KR102700843B1 - Rotor shaft - Google Patents

Abstract

The present invention comprises: a first member having a length; a second member having a length, one side of which is friction-welded to the other side of the first member; and a third member having a length, one side of which is friction-welded to the other side of the second member; wherein the first member, the second member, and the third member are each hollow and communicate with each other and have different strengths, and the members are characterized in that they each have a fitting portion including at least one inclined portion to enable a fitting.

Description

ROTOR SHAFT

The present invention relates to a rotor shaft, and more particularly, to a rotor shaft that serves as a rotational power shaft of an electric vehicle motor, which is formed by friction welding two or more materials, minimizing the occurrence of beads during friction welding, and uniformly forming the center of the rotational axis of the rotor shaft that may occur during rotational friction welding.

In general, a rotor shaft is a rotating shaft to which a rotor, which is a rotating part of a rotating machine such as a generator, electric motor, turbine, or water wheel, is connected, and is composed of a flange and a shaft portion that extends from the flange and has a diameter smaller than the diameter of the flange.

In the past, rotor shafts were mainly manufactured using a cutting processing method. This cutting processing method prepares a raw material having a diameter larger than the flange diameter of the rotor shaft, and then removes the outer surface of the raw material by cutting it using a cutting tool having high hardness.

In addition, when forming longitudinal holes in deep processing, such as for internal cooling water supply channels and hydraulic oil supply channels, through a drilling process, there is a problem that cracks or perforations may occur due to weakening of the internal quality of the metal structure around the holes formed when the longitudinal holes are formed closely together.

In addition, due to the characteristics of the rotor shaft, it is meshed with multiple rotating axes, and each axle is formed of a different material, so the required strength can be formed differently. Accordingly, there is a problem that the degree of wear of each part of the rotor shaft is different.

Accordingly, the industry is continuously and actively conducting research and development to supplement the problems of the rotor shaft.

The present invention has been created to solve the problems of the prior art as described above and to expand the scope of application. The purpose of the present invention is to provide a rotor shaft which, when friction welding different materials using the rotor shaft, enables a rotation axis to be formed consistently and minimizes the occurrence of beads.

The present invention comprises: a first member having a length; a second member having a length, one side of which is friction-welded to the other side of the first member; and a third member having a length, one side of which is friction-welded to the other side of the second member; wherein the first member, the second member, and the third member are each hollow and communicate with each other and have different strengths, and the members may each have a fitting portion including at least one inclined portion to enable a fitting.

Specifically, the first member has a first inclined portion having a tapered cross-section at the first end, the second member has a second inclined portion having a tapered cross-section at the second end and the second end, and the third member has a third inclined portion having a tapered cross-section at the third end, and the first inclined portion and the second inclined portion formed at one end of the second member are fitted so that at least a portion thereof is in contact, and the second inclined portion and the third inclined portion formed at one end of the second member can be fitted so that at least a portion thereof is in contact.

Specifically, when the first inclined portion and the second inclined portion formed at one end of the second member are fitted together, a tolerance in which at least a portion is spaced apart can be formed between the first member and the second member due to the contact between the first inclined portion and the second inclined portion.

Specifically, when the second inclined portion and the third inclined portion formed at the other end of the second member are fitted, a tolerance in which at least a portion is spaced apart can be formed between the second member and the third member due to contact between the second inclined portion and the third inclined portion.

Specifically, the inclination angles of the first inclined portion and the second inclined portion formed on one end of the second member may be the same, and the inclination angles of the second inclined portion and the third inclined portion formed on the other end of the second member may be the same.

Specifically, the inclination angles of the first inclined portion and the second inclined portion formed on one end of the second member may be different, and the inclination angles of the second inclined portion and the third inclined portion formed on the other end of the second member may be different.

Specifically, the first member may be provided by processing the inner and outer surfaces of the ring, the second member may be provided as a ring, and the third member may be provided by processing the inner and outer surfaces of the ring.

Specifically, the tolerance may be such that a receiving space may be formed to receive a bead generated from a bead generating portion.

A rotor shaft according to one embodiment of the present invention has the effect of enabling the rotation axis to be formed identically during friction welding.

In addition, the rotor shaft according to one embodiment of the present invention can minimize the portion of the bead that is generated during friction welding and protrudes outward, thereby minimizing the influence of oil generated on the bead when using the rotor shaft.

FIG. 1 is a drawing schematically showing the overall shape of a rotor shaft according to one embodiment of the present invention.
Figure 2 is a drawing schematically showing a cross-section of a conventional rotor shaft.
Figure 3 is a schematic drawing showing a cross-section of another conventional rotor shaft.
FIG. 4 is a drawing schematically showing a cross-section of a rotor shaft before welding according to one embodiment of the present invention.
FIG. 5 is a schematic drawing showing a cross-section of a welded rotor shaft according to one embodiment of the present invention.
FIG. 6 is a drawing schematically showing a cross-section before welding of a rotor shaft having a fitting according to one embodiment of the present invention.
FIG. 7 is a schematic drawing showing a cross-section after welding of a rotor shaft having a fitting according to one embodiment of the present invention.
FIG. 8 is a drawing schematically showing a cross-section before welding of a rotor shaft having a guide portion according to one embodiment of the present invention.
FIG. 9 is a drawing schematically showing a cross-section after welding of a rotor shaft having a guide portion according to one embodiment of the present invention.
FIG. 10 is a drawing schematically showing a cross-section before welding of a rotor shaft having an inclined portion according to one embodiment of the present invention.
FIG. 11 is a schematic drawing showing a cross-section after welding of a rotor shaft having an inclined portion according to one embodiment of the present invention.
FIG. 12 is a drawing schematically showing a cross-section before welding of a rotor shaft having a facing portion according to one embodiment of the present invention.
FIG. 13 is a schematic drawing showing a cross-section after welding of a rotor shaft having a facing portion according to one embodiment of the present invention.
FIG. 14 is a schematic drawing showing a cross-section before welding of a rotor shaft having a concave portion according to one embodiment of the present invention.
FIG. 15 is a schematic drawing showing a cross-section after welding of a rotor shaft having a concave portion according to one embodiment of the present invention.
FIG. 16 is a drawing schematically illustrating a method for manufacturing a rotor shaft according to one embodiment of the present invention.

The purpose, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. In this specification, when adding reference numerals to components in each drawing, it should be noted that the same components are given the same numerals as much as possible even if they are shown in different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, a detailed description will be provided along with the drawings illustrated below.

FIG. 1 is a drawing schematically showing the overall shape of a rotor shaft according to one embodiment of the present invention, FIG. 2 is a drawing schematically showing a cross-section of a conventional rotor shaft, FIG. 3 is a drawing schematically showing a cross-section of another conventional rotor shaft, FIG. 4 is a drawing schematically showing a cross-section of a rotor shaft before welding according to one embodiment of the present invention, FIG. 5 is a drawing schematically showing a cross-section of a welded rotor shaft according to one embodiment of the present invention, FIG. 6 is a drawing schematically showing a cross-section before welding of a rotor shaft with a fitting part according to one embodiment of the present invention, FIG. 7 is a drawing schematically showing a cross-section after welding of a rotor shaft with a fitting part according to one embodiment of the present invention, FIG. 8 is a drawing schematically showing a cross-section before welding of a rotor shaft with a guide part according to one embodiment of the present invention, FIG. 9 is a drawing schematically showing a cross-section after welding of a rotor shaft with a guide part according to one embodiment of the present invention, FIG. 10 is a drawing schematically showing a cross-section before welding of a rotor shaft with an inclined part according to one embodiment of the present invention, and FIG. 11 is a drawing schematically showing a cross-section before welding of a rotor shaft with a tilted part according to one embodiment of the present invention. FIG. 12 is a drawing schematically illustrating a cross-section after welding of a rotor shaft having an inclined portion, FIG. 13 is a drawing schematically illustrating a cross-section after welding of a rotor shaft having a facing portion according to an embodiment of the present invention, FIG. 14 is a drawing schematically illustrating a cross-section before welding of a rotor shaft having a concave portion according to an embodiment of the present invention, FIG. 15 is a drawing schematically illustrating a cross-section after welding of a rotor shaft having a concave portion according to an embodiment of the present invention, and FIG. 16 is a drawing schematically illustrating a method for manufacturing a rotor shaft according to an embodiment of the present invention.

Referring to Fig. 1, the rotor shaft (10) may be formed in a different shape depending on its use or the connecting portion when used in a motor. For example, the connecting portions of the first body (100), the second body (200), and the third body (300) may be formed differently, so that their shapes (outer surfaces) may be formed differently.

Referring to Fig. 2, a conventional rotor shaft (1) was formed by inserting a mandrel (not shown in the drawing) into the radius of a round bar and then forming a main body (1a) through a radial forging or rotary swaging process. When the inserted mandrel was removed, a hollow space (1b) was formed inside the main body (1a). Since radial forging or rotary swaging is a method of forming by striking a round bar, there is a problem that the shape of the rotor shaft (1) is not uniformly formed around the rotation axis.

Referring to Fig. 3, the conventional rotor shaft (2) was formed by turning the outer diameter of the main body (2a) and then forming a hollow space (2b) through gun drilling. When the hollow space (2b) is formed through gun drilling, there is a problem in that the rotor shaft (1) becomes heavy because the shape of the hollow space (2b) does not correspond to the shape of the main body (2a) and is formed in a straight shape.

In order to solve the problem described above, the rotor shaft (10) of the present invention may be manufactured by dividing it into three parts and processing them, and welding each processed part to manufacture one rotor shaft (10).

Specifically, referring to FIG. 4, the rotor shaft (10) of the present invention may be formed to include a first member (100), a second member (200), and a third member (300) in which a hollow portion (400) may be formed and in which the hollow portion (400) is formed to be in communication. The first member (100), the second member (200), and the third member (300) may be formed to have different strengths. Specifically, the first member (100), the second member (200), and the third member (300) may be formed to extend in the longitudinal direction.

In addition, when looking at the cross-section of the rotor shaft (10) with reference to FIG. 5, the first member (100), the second member (200), and the third member (300) can be arranged in a row and can be formed to extend in one direction. For example, the first member (100) can be formed to extend in the longitudinal direction of the rotor shaft (10). For example, the second member (200) can be formed to extend in the longitudinal direction of the rotor shaft (10). For example, the third member (300) can be formed to extend in the longitudinal direction of the rotor shaft (10). The first member (100), the second member (200), and the third member (300) can be arranged along the longitudinal direction of the rotor shaft (10).

A hollow portion (400) may be formed inside the rotor shaft (10). The hollow portion (400) may be formed in each of the first member (100), the second member (200), and the third member (300). The hollow portions (400) formed in the first member (100), the second member (200), and the third member (300) may be connected to each other. In other words, the hollow portion (400) may be connected from one end of the rotor shaft (10) to the other end, and may penetrate the rotor shaft (10).

In addition, each member of the rotor shaft (10) may be in the form of a circular bar. The first member (100), the second member (200), and the third member (300) may be in the form of a machined outer surface or inner surface of the circular bar.

In addition, the first member (100) of the rotor shaft (10) can be coupled with another part and supported by the next part. The rotor (not shown) can be coupled to the second member (200). The second member (200) can receive rotational force from the rotor (not shown). The third member (300) can be coupled to a load and transmit the rotational force.

The first member (100) may be formed by extending from one side to the other side. One side of the first member (100) may be a first end portion (101). The other side of the first member (100) may be a first end portion (102). The first end portion (101) may refer to a left end portion of the first member (100) in FIG. 4, and the first end portion (102) may refer to a right end portion in FIG. 4. The longitudinal direction of the first member (100) may be a direction from the first end portion (101) toward the first end portion (102). The rotational axis of the first member (100) may be the same as the center line (CL) of the rotor shaft (10). The longitudinal direction of the first member (100) may be parallel to the rotational axis of the first member (100).

In addition, the first end portion (102) of the first member (100) may be extended by a first length (L1). The first length (L1) may mean a length lost when the first member (100) and the second member (200) are in contact. The first member (100) and the second member (200) may be joined by welding. For example, the first member (100) and the second member (200) may be joined by a friction welding method. In the process of joining the first member (100) and the second member (200), the longitudinal length of the first member (100) may be shortened by the first length (L1).

In addition, the first member (100) may include a first main body (110). The first main body (110) may be formed by processing the outer surface and the inner surface of the ring. For example, the first main body (110) may be formed by cutting the outer surface and the inner surface of the ring.

The first hollow (120) can be formed to penetrate the first body (110) in the longitudinal direction of the first body (110). The first hollow (120) can be formed by processing the inner side of the round bar. For example, the first hollow (120) can be formed by cutting the inner side of the round bar. As a result, the first member (100) can be manufactured without a forging facility. As a result, the first member (100) can be manufactured with a uniform shape with respect to the rotational axis of the first member (100). The first hollow (120) can be formed to correspond to the outer shape of the first body (110). As a result, the first member (100) can be made as lightweight as possible.

Additionally, the radius of the first hollow (120) may vary along the longitudinal direction of the first member (100). The radius of the first hollow (120) may gradually increase from one side to the other.

The second member (200) may be formed by extending from one side to the other side. One side of the second member (200) may be the second end (201). The other side of the second member (200) may be the second other end (202). The second end (201) may refer to the left end in FIG. 4, and the second other end (202) may refer to the right end in FIG. 4.

The longitudinal direction of the second member (200) may be a direction from the second end (201) to the second end (202). The rotational axis of the second member (200) may be the same as the center line (CL) of the rotor shaft (10). The longitudinal direction of the second member (200) may be parallel to the rotational axis of the second member (200). The longitudinal direction of the second member (200) may be the same as the longitudinal direction of the first member (100). The longitudinal direction of the second member (200) may be the same as the longitudinal direction of the third member (300).

The second end (201) of the second member (200) may be extended by a second length (L2). The second length (L2) may refer to a length lost when joining the second member (200) and the first member (100). The second member (200) and the first member (100) may be joined by welding. For example, the first member (100) and the second member (200) may be joined by friction welding. In the process of joining the first member (100) and the second member (200), the longitudinal length of the second member (200) may be shortened by the second length (L2).

The second end (202) of the second member (200) may be extended by a third length (L3). The third length (L3) may refer to a length lost when joining the second member (200) and the third member (300). The second member (200) and the third member (300) may be joined by welding. For example, the second member (200) and the third member (300) may be joined by friction welding. In the process of joining the second member (200) and the third member (300), the longitudinal length of the second member (200) may be shortened by the third length (L3).

The second member (200) may include a second body (210). The second hollow (220) may be formed to penetrate the second body (210) in the longitudinal direction of the second body (210). The radius of the second hollow (220) may be constant along the longitudinal direction of the second member (200). The second member (200) may be provided as a circular bar. The second hollow (220) may be the same as the hollow of the circular bar. As a result, the second member (200) may be manufactured without a forging facility. As a result, the second member (200) may be manufactured in a uniform shape with respect to the rotational axis of the second member (200).

The third member (300) may be formed by extending from one side to the other side. One side of the third member (300) may be a third end (301). The other side of the third member (300) may be a third end (302). The third end (301) may refer to a left end in FIG. 4, and the third end (302) may refer to a right end in FIG. 4. The longitudinal direction of the third member (300) may be a direction from the third end (301) toward the third end (302). The rotational axis of the third member (300) may be the same as the center line (CL) of the rotor shaft (10). The longitudinal direction of the third member (300) may be parallel to the rotational axis of the third member (300).

The third end (301) of the third member (300) may be extended by a fourth length (L4). The fourth length (L4) may refer to a length that is lost when the third member (300) and the second member (200) are joined. The third member (300) and the second member (200) may be joined by welding. For example, the second member (200) and the third member (300) may be joined by friction welding. In the process of joining the second member (200) and the third member (300), the longitudinal length of the third member (300) may be shortened by the fourth length (L4).

Additionally, the bead generated when joining the first member (100) and the second member (200) or when joining the second member (200) and the third member (300) may be formed to protrude inside or outside the rotor shaft (10).

For example, when friction-bonding a first member (100) and a second member (200) occurs, a first bead (130) and a second one-sided bead (231) may occur on both sides based on the first joining portion (J1), and when friction-bonding a second member (200) and a third member (300) occurs, a second other-sided bead (232) and a third bead (330) may occur on both sides based on the second joining portion (J2).

The third member (300) may include a third main body (310). For example, the third main body (310) may be formed by machining the outer surface and the inner surface of a circular bar. The third main body (310) may be formed by cutting the outer surface and the inner surface of the circular bar. For example, the third main body (310) may be formed by machining the outer surface of a cylinder and machining a hole on the inner surface of the cylinder. The third main body (310) may be formed by cutting the outer surface of a cylinder, drilling a hole on the inner surface of the cylinder, and cutting the inner surface of the hole.

The third hollow (320) can be formed to penetrate the third main body (310) in the longitudinal direction of the third main body (310). The third hollow (320) can be formed by processing the inner side of the round bar. For example, the third hollow (320) can be formed by cutting the inner side of the round bar. As a result, the third member (300) can be manufactured without a forging facility. As a result, the third member (300) can be manufactured with a uniform shape with respect to the rotational axis of the third member (300).

The radius of the third hollow (320) can vary along the longitudinal direction of the third member (300). The radius of the third hollow (320) can gradually decrease from one side to the other.

The first end (102) of the first member (100) can be joined to the second end (201) of the second member (200), and the second end (202) of the second member (200) can be joined to the third end (301) of the third member (300). For example, each of the joinings can be joined using friction welding. After joining, the first hollow (120), the second hollow (220), and the third hollow (320) can be connected to each other.

Friction welding can be used to join different materials. It can be a part that supports the rotor shaft (10) of the first member (100). The rigidity required for the first member (100) can be lower than the rigidity required for the second member (200) and the third member (300). The rigidity of the material constituting the first member (100) can be relatively lower than the rigidity of the material constituting the second member (200) and the third member (300). This can reduce the cost.

Referring to FIG. 5, a portion where the first member (100) and the second member (200) are joined may be referred to as a first joining portion (J1). A bead (130, 230 (231)) may be formed in the first joining portion (J1). The bead (130, 230 (231)) may mean at least one of the first bead (130) and the second one-sided bead (231).

The portion where the second member (200) and the third member (300) are joined may be referred to as a second joining portion (J2). A bead (230 (232), 330) may be formed in the second joining portion (J2). The bead (230 (232), 330) may mean at least one of the second other bead (232) and the third bead (330).

The first member (100) may include a first bead (130). The first bead (130) may be formed at a first end (102) of the first member (100). The first bead (130) may be formed to protrude inwardly from the first body (110) of the first body (110), and may be formed to protrude in an outwardly direction of the first body (110). The inwardly direction of the first body (110) may be a direction toward the first hollow (120), and the outwardly direction of the first body (110) may mean a direction away from the first hollow (120).

The first bead (130) may be formed to protrude outwardly from the first main body (110), and the outward direction of the first main body (110) may be a direction away from the first hollow (120). The first bead (130) protruding outwardly from the first main body (110) may be removed through outer processing of the first main body (110).

The first member (100) may include a second bead (230). The second bead (230) may include a second one-sided bead (231). The second one-sided bead (231) may be formed on a second end (201) of the second member (200). The second one-sided bead (231) may be formed to protrude inwardly from the second body (210) of the second body (210). The inward direction of the second body (210) may be a direction toward the second hollow (220).

The second one-sided bead (231) may be formed to protrude from the second main body (210) in an outward direction of the second main body (210). The outward direction of the second main body (210) may be a direction away from the second hollow (220). The second one-sided bead (231) protruding in the outward direction of the second main body (210) may be removed through outer processing of the second main body (210).

The second bead (230) may include a second other-side bead (232), and the second other-side bead (232) may be formed on the second other end (202) of the second member (200). The second other-side bead (232) may be formed to protrude in the inner and outer directions of the second main body (210). The inner direction of the second main body (210) may be in the direction of the second hollow (220) portion, and the outer direction may be in the opposite direction of the second hollow (220) portion. The second other-side bead (232) may be removed through outer processing.

The third member (300) may include a third bead (330). The third bead (330) may be formed on a third end (301) of the third member (300). The third bead (330) may be formed to protrude inwardly and outwardly from the third main body (310) of the third main body (310). The inward direction of the third main body (310) may be a direction toward the third hollow (320) portion, and the outward direction may be an opposite direction to the third hollow (320) portion.

The third bead (330) is formed to protrude outwardly from the third main body (310) and can be removed through external processing.

The hollow portion (400) of the rotor shaft (10) according to one embodiment of the present invention may include a first hollow portion (120), a second hollow portion (220), and a third hollow portion (320). When oil is injected into the hollow portion (400), a problem of oil accumulating on the beads may occur.

Accordingly, another embodiment of the present invention is an embodiment that can minimize the influence of beads on oil. This will be described in detail below.

According to one embodiment of the present invention with reference to FIGS. 6 and 7, a first member (100) having a length; a second member (200) having a length and one side of which is friction-welded to the other side of the first member (100); and a third member (300) having a length and one side of which is friction-welded to the other side of the second member (200); wherein the first member (100), the second member (200), and the third member (300) are each hollow and communicate with each other and have different strengths, and the members may each have at least one fitting portion (150, 250, 350) to enable fitting.

The first member (100), the second member (200), and the third member (300) are each formed so as to be capable of being joined and may be friction-joined using rotational friction.

The first member (100) may form a first fitting portion (150) at the first other end (102), the second member (200) may form a second fitting portion (250) at the second one end (201) and the second other end (202), and the third member (300) may form a third fitting portion (350) at the third one end (301).

Here, the first fitting portion (150) to the third fitting portion (350) may be formed to extend from each of the first to third main bodies (110, 210, 310) and may be formed to extend to half the thickness of the main body. Accordingly, when the fitting portions are joined together, there is an effect of being able to fix the central axis so that it does not become distorted.

In addition, when the first to third fitting parts (350) are combined, a first tolerance (H1) may be formed. Here, the first tolerance (H1) may be a space where a bead generated by friction welding is positioned while the center axis is fixed by the fitting part. Accordingly, it is possible to prevent the bead from protruding outward or inward.

The bead is generated during friction welding between the first fitting portion and the second fitting portion (250) or between the second fitting portion (250) and the third fitting portion (350), and may be generated at the bead generating portion (1000a, 1000b) that is in contact with each other. The bead generating portion (1000a, 1000b) may be generated when heat is generated due to direct friction and the heat spreads to the surroundings, reaching the melting point and becoming one. At this time, a certain degree of proximity may be required between them. For example, if the amount of beads generated during friction welding is too small, a shape that is dented inward may occur after friction welding is completed, which may be fatal to durability. Accordingly, an operation of rotating and approaching each other may be performed during friction welding. At this time, it may be to ensure that the beads are positioned within the first tolerance (H1).

Below, a rotor shaft (10) having a fitting part (150, 250, 350) including a guide part (151, 251, 351) will be described in detail.

According to one embodiment of the present invention with reference to FIGS. 8 and 9, a first member (100) having a length; a second member (200) having a length and one side of which is friction-welded to the other side of the first member (100); and a third member (300) having a length and one side of which is friction-welded to the other side of the second member (200); wherein the first member (100), the second member (200), and the third member (300) are each hollow and communicate with each other and have different strengths, and the members may each have a fitting part (150, 250, 350) including at least one guide part (151, 251, 351) so that the members can be fitted together.

Here, the first member (100), the second member (200), and the third member (300) may each be provided in a cylindrical shape and may be integrated by friction welding. At this time, each member may have a fitting part so that the central axis is formed identically.

Here, the fitting portion may be formed on each of the first member (100), the second member (200), and the third member (300), and may be formed so that the central axes are fitted in the same manner when the first member (100) and the second member (200) are friction-welded.

Specifically, a first fitting portion (150) may be formed at a first length (L1) formed at the right end of a first member (100), a second fitting portion (250) may be formed at a second length (L2) formed at the left end of a second member (200) and a third length (L3) formed at the right end of the second member (200), and a third fitting portion (350) may be formed at a fourth length (L4) formed at the left end of a third member (300). For example, a first fitting part (150) may be formed at a first end (102) of a first member (100), a second fitting part (250) may be formed at a second end (201) and a second end (202) of a second member (200), and a third fitting part (350) may be formed at a third end (301) of a third member (300).

For example, when the first member (100) and the second member (200) are friction-welded, the first fitting portion (150) formed on the first member (100) and the second member (200) and the second fitting portion (250) formed on one end of the second member (200) are fitted so that the central axes of the first member (100) and the second member (200) coincide, and when friction welding is performed later, the central axes are prevented from being twisted due to rotation. In addition, the second fitting portion (250) formed on the other end of the second member (200) and the third fitting portion (350) formed on the third member (300) are fitted so that the central axes of the second member (200) and the third member (300) coincide, and when friction welding is performed later, the central axes are prevented from being twisted due to rotation.

The first member (100) and the second member (200) fitted by the fitting may be formed at a predetermined distance apart to form a second tolerance (H2). Here, an example of the second tolerance (H2) may be formed differently depending on the distance that the first member (100) and the second member (200) are close to each other, but preferably, the second tolerance (H2) may be formed to have the size of the bead that generates friction welding. In addition, the part that generates heat during friction welding may be the part that is in contact with and overlaps each other (the bead generating part (1000a, 1000b)), and the size of the bead generating part (1000a, 1000b) and the size of the second tolerance (H2) may be formed to have the most efficient size. For example, if the bead generating portion (1000a, 1000b) is formed narrowly, the area that generates heat is reduced, so friction welding may not be completely achieved. In addition, if the bead generating portion (1000a, 1000b) is formed too large, heat is easily generated, but the bead may be formed larger than the volume of the second tolerance (H2) and protrude. It may be desirable to form an optimal size to prevent this. The bead generating portion (1000a, 1000b) may be formed on the contact surfaces of the first member (100) and the second member (200) and the contact surfaces of the second member (200) and the third member (300), respectively.

Additionally, each of the fittings formed in the first member (100), the second member (200), and the third member (300) may form a guide member (151, 251, 351).

Here, the guide portion (151, 251, 351) may be configured to maintain the size of the second tolerance (H2) constant.

For example, it may be formed to have at least a portion of the length of the second tolerance (H2). Accordingly, when the first member (100) and the second member (200) are brought into contact, the second tolerance (H2) may be formed as long as the length of the guide portion (151, 251, 351). At this time, the second tolerance (H2) may be formed so that the bead generated from the bead generating portion (1000a, 1000b) by friction welding is formed gently without a protruding portion inside the second tolerance (H2).

In addition, the first member (100), the second member (200), and the third member (300) may be formed to be connected to different places when used in a motor, and thus different strengths may be required. Depending on the different strengths required, the first member (100), the second member (200), and the third member (300) may be formed of different materials, and may be welded using friction welding rather than integral welding to form them of different materials.

According to one embodiment of the present invention, the first member (100) has a first fitting portion having an “L” shape in cross-section at the first other end (102), the second member (200) has a second fitting portion (250) having an “L” shape in cross-section at the second one end (201) and the second other end (202), and the third member (300) has a third fitting portion (350) having an “L” shape in cross-section at the third one end (301), and the first fitting portion and the second fitting portion (250) formed at one end of the second member (200) may be fitted, and the second fitting portion (250) and the third fitting portion (350) formed at the other end of the second member (200) may be fitted.

Here, the second fitting portion (250) formed on one end of the first fitting portion (150) and the second member (200) is formed to be fitted and may be formed to have a thickness equal to half of the wall thickness of the second member (200), but is not limited thereto, and the thickness of the first fitting portion formed on the outer surface may be formed thicker. In addition, the inner and outer sides of the second fitting portion (250) formed on one end of the first fitting portion and the second member (200) may be mutually variable. For example, the second fitting portion (250) may be formed to surround the first fitting portion (not shown in the drawing).

In addition, the second fitting portion (250) formed on the other end of the second member (200) and the third fitting portion (350) formed on the third member (300) may be formed to be fit-fittable so that the second member (200) and the third member (300) can be fit-fittable. The fitting method of the first fitting portion (150) and the second fitting portion (250) described above may be used in the same manner. For example, they may be formed to have the same thickness and friction-welded using frictional force due to rotational force after being fit-fitted.

This type of fitting method can enable friction welding to be achieved while maintaining the rotational axes of the first member (100), the second member (200), and the third member (300) the same.

According to one embodiment of the present invention, the first fitting part (150), the second fitting part (250), and the third fitting part (350) may be formed to have the same outer diameter and inner diameter, and may form a second tolerance (H2) such that at least a portion of them is spaced apart when each is fitted.

Here, since the second fitting portion (250) is formed in multiple numbers at one end and the other end of the second member (200) and has a cylindrical shape with the same thickness, the thicknesses of the first fitting portion (150), the second fitting portion (250), and the third fitting portion (350) can be formed to be the same. For example, the widths of the protruding portions of the first fitting portion (150) and the second fitting portion (250) can be the same, and the widths of the protruding portions of the second fitting portion (250) and the third fitting portion (350) can be formed to be the same. In addition, the outermost diameter and the inner diameter of the first fitting portion (150) and the second fitting portion (250) can be the same, and the second fitting portion (250) and the third fitting portion (350) can also be the same.

In addition, the first fitting portion (150), the second fitting portion (250), and the third fitting portion (350) may be spaced apart from each other by a predetermined distance when fitted, thereby forming a second tolerance (H2). The second tolerance (H2) may be a space where a bead generated during friction welding is located. If a bead generated from a bead generating portion (1000c, 1000d) is formed to protrude to the outside or inside, oil or foreign substances may be generated in the bead, thereby weakening durability, and therefore, it may be important to minimize the bead.

Here, the bead generating portion (1000c, 1000d) may be an area where the first fitting portion (150) and the second fitting portion (250) come into contact and an area where the second fitting portion (250) and the third fitting portion (350) come into contact.

According to one embodiment of the present invention, the first fitting part (150) includes a first guide part (151) that is formed protrudingly on a part of the cross-section that contacts the second fitting part (250), the second fitting part (250) includes a second guide part (251) that is formed protrudingly on a part of the cross-section that contacts the first fitting part (150) and the third fitting part (350), and the third fitting part (350) includes a third guide part (351) that is formed protrudingly on a part of the cross-section that contacts the second fitting part (250), and when the first fitting part (150) and the second fitting part (250) are fitted, the width of the second tolerance (H2) is formed uniformly by the first guide part (151) and the second guide part (251), and when the second fitting part (250) and the third fitting part (350) are fitted, At this time, the width of the second tolerance (H2) may be formed at a constant level by the second guide portion (251) and the third guide portion (351).

Here, the guide part may include a first guide part (151), a second guide part (251), and a third guide part (351).

In addition, the second guide part (251) may include a second one-side guide part formed at a second length (L2) of the left end of the second main body (210) and a second other-side guide part formed at a third length (L3) of the right end of the second main body (210).

Specifically, the first guide part (151) and the second one-side guide part may be combined, and the second other-side guide part and the third guide part (351) may be combined.

When the first fitting part (150) and the second fitting part (250) are combined, a state of being spaced apart by a certain distance can be maintained by the first guide part (151) and the second one-sided guide part.

For example, when the first fitting part (150) and the second fitting part (250) are combined, the first guide part (151) comes into contact with the left end of the second fitting part (250) and is fixed so as not to advance any further, so that the horizontal length of the second tolerance (H2) has the horizontal length of the first guide part (151). Similarly, the second one-sided guide part is formed so as to come into contact with the first fitting part (150) and is fixed so as not to advance any further, so that the horizontal length of the second tolerance (H2) has the horizontal length of the second one-sided guide part.

In addition, when the second fitting part (250) and the third fitting part (350) are combined, the second other-side guide part comes into contact with the right end of the third fitting part (350) and is fixed so as not to advance any further, so that the horizontal length of the second tolerance (H2) has the horizontal length of the second other-side guide part. Similarly, the second other-side guide part is formed so as to come into contact with the third fitting part (350) and is fixed so as not to advance any further, so that the horizontal length of the second tolerance (H2) has the horizontal length of the third guide part (351).

According to one embodiment of the present invention, the first guide part (151), the second guide part (251), and the third guide part (351) may be formed to have at least a portion of a thickness from the bead generating part (1000c, 1000d) where friction occurs between the fitting parts.

Here, the bead generating portion (1000c, 1000d) may be a portion that is subject to friction after the first member (100) and the second member (200) or the second member (200) and the third member (300) are joined during friction welding. Accordingly, the bead generating portion (1000c, 1000d) may be a portion where beads are generated by heat generated due to rotation of the first member (100) to the third member.

In addition, the bead generating portion (1000c, 1000d) may be a contact portion formed at the second end (201) and the second end (202) based on the second member (200).

For example, the part where one side of the first guide part (151) and the second guide part (251) are in contact may be a bead generating part (1000c, 1000d).

At this time, the guide portion (151, 252, 352) may be formed to have a constant thickness based on the horizontal portion of the bead generating portion (1000c, 1000d).

Specifically, the guide portion may have a constant thickness. For example, the length of the second tolerance (H2) formed by the first guide portion (151) and the second guide portion (251) is the same, and since the friction area and the amount of beads generated are the same, the thickness of the guide portions may be the same in order to make the area of the protruding portion the same.

According to one embodiment of the present invention, the lengths of the protruding portions of the first fitting portion (150) and the second fitting portion (250) may be the same, the lengths of the first guide portion (151) and the second guide portion (251) formed at the second end (201) may be the same, and the lengths of the second guide portion (251) formed at the second other end (202) and the third guide portion (351) may be the same.

Here, the first fitting portion (150) may be a portion extended from the first main body (110). Specifically, the first fitting portion (150) may be formed at the first other end (102) of the first main body (110) and may be extended to have a thickness equal to half the thickness of the first main body (110).

The second fitting portion (250) may be a portion extended from the second main body (210). Specifically, the second fitting portion (250) may be formed at each of the second end (201) and the second other end (202) of the second main body (210). In addition, it may be extended to have a thickness equal to half the thickness of the second main body (210).

The third fitting portion (350) may be a portion extended from the third main body (310). Specifically, the third fitting portion (350) may be formed on the third end (301) of the third main body (310) and may be formed to have a thickness that is half the thickness of the third main body (310).

In this way, when the first fitting part (150) to the third fitting part (350) are joined to each other by having the same thickness, the center axis is prevented from being misaligned, and the first member (100), the second member (200), and the third member (300) can all form the same melting area due to the generation of heat during friction welding.

According to one embodiment of the present invention, the first member (100) may be provided by processing the inner and outer surfaces of a circular bar, the second member (200) may be provided as a circular bar, and the third member (300) may be provided by processing the inner and outer surfaces of the circular bar.

Here, the rotation may mean the form of a first member (100), a second member (200), and a third member (300).

The second absence (200) may be in the shape of a cylinder with the interior also being cut in the same manner.

The first member (100) and the third member (300) may have the radii of the first hollow (120) portion and the third hollow (320) portion formed inside different along the longitudinal direction.

Specifically, the first member (100) may have a radius that becomes smaller as it moves toward the first end (101). For example, it may be formed so that the radius becomes smaller in a stepwise manner. At this time, the thickness of the outer pillar of the first main body (110) is maintained at a certain thickness or more to maintain strength, and is formed to have a maximum thickness at which strength is maintained, so that material costs can be minimized.

In addition, the third absence (300) may be formed so that the radius of the third hollow (320) portion becomes smaller as it approaches the third other end (302). For example, the third hollow (320) portion may be formed so that the radius becomes rapidly smaller in a funnel shape as it approaches the third other end (302), and then the smaller radius is maintained.

According to one embodiment of the present invention, the second tolerance (H2) may be formed by a receiving space that receives a bead generated from a bead generating unit (1000c, 1000d).

Here, the bead generating portion (1000c, 1000d) may be a portion that is melted due to heat generated by friction when friction welding is performed in a state where the first member (100) to the third member (300) are joined in a fitting manner of the first fitting portion (150) to the third fitting portion (350) as described above. When the welding of the dissimilar materials is completed by melting, the melted area hardens and generates a bead.

These beads can be areas where oil builds up and creates impurities in the final product, so minimizing them may be best for your product use.

Accordingly, the accommodation space formed by the second tolerance (H2) can position the beads to minimize beads generated on the outside and inside of the rotor shaft.

Below, an example of a rotor shaft (10) having a tailored portion (150, 250, 350) including an inclined portion (152, 252, 352) is described in detail.

The fitting according to one embodiment of the present invention with reference to FIGS. 10 and 11 may include an inclined portion.

Specifically, the first member (100) may include a first fitting portion (150) formed at a first length (L1) of the first other end and a first inclined portion (152) having a tapered shape.

In addition, the second member (200) may include a second inclined portion (252) having a tapered shape, a second fitting portion (250) formed at a second length (L2) of the second one-sided end, and a second inclined portion (252) having a tapered shape, a second fitting portion (250) formed at a third length (L3) of the second other-sided end.

Additionally, the third absence (300) may include a third slanted portion (352) having a tapered shape and a third fitting portion (350) formed at the fourth length (L4) of the third one-sided end.

In addition, the first inclined portion (152), the second inclined portion (252), and the third inclined portion (352) may be provided in an entirely tapered shape, but are not limited thereto, and at least a portion may be a tapered shape, and at least one of the first inclined portion (152), the second inclined portion (252), and the third inclined portion (352) may be in an angular step shape, but any shape that can form friction may be formed.

According to one embodiment of the present invention, the first member (100) has a first inclined portion (152) provided with a tapered cross-section at the first other end (102), the second member (200) has a second inclined portion (252) provided with a tapered cross-section at the second one end (201) and the second other end (202), and the third member (300) has a third inclined portion (352) provided with a tapered cross-section at the third one end (301), and the first inclined portion (152) and the second inclined portion (252) formed at one end of the second member (200) are fitted so that at least a portion thereof is in contact, and the second inclined portion (252) and the third inclined portion (352) formed at one end of the second member (200) can be fitted so that at least a portion thereof is in contact.

Here, the first inclined portion (152) may be formed at a first length (L1) formed at the first other end (102) of the first member (100). It may be an area forming a first joining portion (J1) that is joined during friction welding.

In addition, the second inclined portion (252) may be formed at both ends of the second member (200). Specifically, it may be formed at a second length (L2) formed at a second end (201) of the second main body (210), and may be formed at a third length (L3) formed at a second other end (202) of the second main body (210). The second length (L2) and the third length (L3) may form a first joining portion (J1) and a second joining portion (J2), respectively, during friction welding.

Additionally, the third inclined portion (352) may be formed at a fourth length (L4) formed at the third end (301) of the third member (300). The fourth length (L4) may form a second joining portion (J2) during friction welding.

In addition, when the first member (100), the second member (200), and the third member (300) are friction-welded by rotational force in a combined state, in order to generate heat due to friction, at least some of the first inclined portion (152) and the second inclined portion (252) may be in contact, and at least some of the second inclined portion (252) and the third inclined portion (352) may be in contact. In addition, the first member (100) and the second member (200) or the second member (200) and the third member (300) may be brought into close proximity, respectively, during friction welding.

According to one embodiment of the present invention, when the first inclined portion (152) and the second inclined portion (252) formed at one end of the second member (200) are fitted together, a third tolerance (H3) can be formed between the first member (100) and the second member (200) by at least a portion of the space due to the contact between the first inclined portion (152) and the second inclined portion (252).

Here, the third tolerance (H3) may be the length spaced between the first main body (110) and the second main body (210) when the first inclined portion (152) and the second inclined portion (252) are in contact.

The third tolerance (H3) may be formed when the first inclined portion (152) and the second inclined portion (252) come into contact and cannot be approached any further, and thus may be formed to have a constant size.

According to one embodiment of the present invention, when the second inclined portion (252) and the third inclined portion (352) formed at the other end of the second member (200) are fitted, a third tolerance (H3) can be formed between the second member (200) and the third member (300) by at least a portion of the space due to the contact between the second inclined portion (252) and the third inclined portion (352).

Here, the third tolerance (H3) may be the length spaced between the second main body (210) and the third main body (310) when the second inclined portion (252) and the third inclined portion (352) are in contact.

The third tolerance (H3) may be formed when the second inclined portion (252) and the third inclined portion (352) come into contact and cannot be approached any further, and thus may be formed to have a constant size.

According to one embodiment of the present invention, the inclination angles of the first inclined portion (152) and the second inclined portion (252) formed at one end of the second member (200) may be the same, and the inclination angles of the second inclined portion (252) formed at the other end of the second member (200) and the third inclined portion (352) may be the same.

Here, the first inclined portion (152) and the second inclined portion (252) may have the same inclination angle, so that when they come into contact, the entire inclined surface may come into contact.

In addition, the second inclined portion (252) and the third inclined portion (352) may have the same inclination angle, so that when they come into contact, the entire inclined surface may come into contact.

When the entire inclined surface is in contact, the frictional area increases, which increases the frictional force and the resulting heat generation, enabling rapid friction welding.

According to one embodiment of the present invention, the inclination angles of the first inclined portion (152) and the second inclined portion (252) formed at one end of the second member (200) may be different, and the inclination angles of the second inclined portion (252) formed at the other end of the second member (200) and the third inclined portion (352) may be different.

Here, the inclination angles of the first inclined portion (152) and the second inclined portion (252) may be formed differently so that only a portion of them comes into contact when they come into contact.

In addition, the inclination angles of the second inclined portion (252) and the third inclined portion (352) may be formed differently so that only a portion of them comes into contact when they come into contact.

When the slopes are formed differently, only a portion of the first slope portion (152) and the second slope portion (252) or the second slope portion (252) and the third slope portion (352) may come into contact, and accordingly, a space may be additionally formed between the first main body (110) and the second main body (210) or between the second main body (210) and the third main body (310) so that the bead can be positioned.

According to one embodiment of the present invention, the first member (100) may be provided by processing the inner and outer surfaces of a circular bar, the second member (200) may be provided as a circular bar, and the third member (300) may be provided by processing the inner and outer surfaces of the circular bar.

Here, the circle can mean a cylindrical shape.

The first member (100), the second member (200), and the third member (300) may each be formed in different shapes, and may be provided with different shapes depending on the use after being pressed.

For this purpose, a separate processing step can be used. In addition, the shape of the hollow interior can be formed differently to minimize the material, thereby reducing the weight while maintaining strength.

According to one embodiment of the present invention, the third tolerance (H3) may be formed with a receiving space that receives a bead generated from a bead generating unit (1000e, 1000f).

Here, the accommodation space may be a space formed by the third tolerance (H3).

The receiving space may be a space that receives beads generated during friction welding. Beads are generated on the inside or outside of the rotor shaft (10) and cause oil residues to accumulate during use, so it may be desirable to remove them as much as possible.

Accordingly, the rotor shaft (10) may form an accommodation space by forming a third tolerance (H3) when the first inclined portion (152) and the second inclined portion (252) or the second inclined portion (252) and the third inclined portion (352) come into contact.

The bead generating portion (1000e, 1000f) may be an area where the first inclined portion (152) and the second inclined portion (252) are in contact, or an area where the second inclined portion (252) and the third inclined portion (352) are in contact.

For example, it could be an area where heat is generated by friction due to rotational force. It could be a bead that forms as the metal melts and solidifies again due to the heat.

The tolerances (H1, H2, H3) described above can be applied in various ways depending on the shape of the fitting (150, 250, 350).

According to one embodiment of the present invention with reference to FIGS. 12 and 13, the fitting portion (150, 250, 350) may include a facing portion (153, 253, 353).

Specifically, the first member (100) may include a first facing portion (153) having at least a portion of a first fitting portion (150) formed in a first length (L1) of the first other end portion in a protruding shape.

Additionally, the second member (200) may include a second facing portion (253) having at least a portion of a second fitting portion (250) formed in a second length (L2) of the second one-sided end portion in a protruding shape.

Additionally, the second member (200) may include a second facing portion (253) having at least a portion of a second fitting portion (250) formed in a third length (L3) of the second other end portion in a protruding shape.

Additionally, the third member (300) may include a third facing member (353) having at least a portion of a third fitting member (350) formed on the fourth fork of the third one-sided end portion in a protruding shape.

According to one embodiment of the present invention, the first facing portion (153) is formed to be in contact with at least a portion of the second end portion (201), the second facing portion (253) formed on one end of the second member (200) is formed to be in contact with at least a portion of the first other end portion (102), and the third facing portion (353) is formed to be in contact with at least a portion of the other end of the second member (200), so that the first member (100), the second member (200), and the third member (300) can be fitted together.

Here, the rotor shaft (10) may be fitted by the combination of the first facing portion (153) and the second facing portion (253) formed on the second end portion (201).

The fitted rotor shaft (10) can be formed identically without the center axis being distorted when the first member (100) and the second member (200) are combined.

According to one embodiment of the present invention, the fitted first member (100) and second member (200) or the second member (200) and third member (300) may be friction-welded by rotational force.

At this time, a bead may be generated at the bead generating portion (1000g) where the first member (100) and the second member (200) are in contact.

Additionally, beads may be generated at the bead generating portion (1000h) where the second member (200) and the third member (300) are in contact.

According to one embodiment of the present invention, the first facing portion (153) region and the third facing portion (353) region may be laser welded, and the second facing portion (253) region may be TIG welded.

Specifically, the second facing portion (253) formed to be weldable on the outside of the rotor shaft (10) may be TIG welded.

Conversely, the first facing portion (153) and the third facing portion (353) formed outside the rotor shaft (10) so that TIG welding is impossible may be laser welded.

The rotor shaft (10) of the present invention may be formed by welding the first member (100), the second member (200), and the third member (300). At this time, various welding methods may be used, and friction welding, TIG welding, laser welding, etc. may be used as described above. These welding methods may be used singly or polymerically.

According to one embodiment of the present invention, when welding the first facing portion (153), the second facing portion (253), and the third facing portion (353), only the areas in contact may be welded, but this is not limited thereto. For example, as shown in FIG. 13, when the second member (200) and the third member (300) are welded, when welding the second facing portion (253) formed on the second other end portion (202) of the second member (200), not only the second facing portion (253) but also the entire thickness of the third main body (310) may be welded. Such welding can further improve durability.

Here, the method of welding the entire thickness of the third main body (310) may be used for the entire first facing portion (153), the second facing portion (253), and the third facing portion (353). For example, the entire thickness may be welded by using a method such as increasing the heat generated during TIG welding or laser welding.

Below, a detailed description will be given of a rotor shaft (10) in which a fitting portion (150, 250, 350) includes a facing portion (153, 253, 353), and the facing portion (153, 253, 353) has a concave portion (154, 254, 354).

According to one embodiment of the present invention with reference to FIGS. 14 and 15, the invention comprises: a first member (100) having a length; a second member (200) having a length, one side of which is friction-welded to the other side of the first member (100); and a third member (300) having a length, one side of which is friction-welded to the other side of the second member (200); wherein the first member (100), the second member (200), and the third member (300) are each hollow and communicate with each other and have different strengths, and the members each have at least one facing portion (150, 250, 350) including a fitting portion so that the facing portions (153, 253, 353) can have a concave portion (154, 254, 354) having at least a portion that is concave.

Specifically, the first member (100) may include a first facing portion (153), and the first facing portion (153) may have a first concave portion (154). The first concave portion (154) may be a blank area having a shape symmetrical on both sides so that its center coincides with the first facing portion (153). In this case, a part of the first concave portion (154) may include a shape in which a part of the second member (200) is missing.

In addition, the second member (200) may include a second facing portion (253), and the second facing portion (253) may have a second concave portion (254). The second concave portion (254) may be formed at a second length (L2) and a third length (L3) formed at one end and the other end of the first member (100), and may have a shape in which at least a portion is missing. For example, it may be formed at the lower ends of one end and the other end of the second facing portion (253), and may be formed at the lower middle portions of one end and the other end. At this time, the second concave portion (254) may be provided in a shape in which a part of the center coincides with the end of the second facing portion (253) and both sides are symmetrical.

In addition, the third member (300) may include a third facing portion (353), and the third facing portion (353) may have a third concave portion (354). The third concave portion (354) may be formed at a fourth length (L4) formed at one end of the third member (300). For example, the third concave portion (354) may be a blank area having a shape symmetrical on both sides and having a center that coincides with the third facing portion (353). In this case, a part of the third concave portion (354) may include a shape in which a part of the third member (300) is removed.

According to one embodiment of the present invention, the first member (100) has a first facing portion (153) formed so that at least a portion protrudes from the first other end portion (102), the second member (200) has a second facing portion (253) formed so that at least a portion protrudes from each of the second one end portion (201) and the second other end portion (202), and the third member (300) has a third facing portion (353) formed so that at least a portion protrudes from the third one end portion (301), and the first facing portion (153) is formed so as to be in contact with at least a portion of the second one end portion (201), the second facing portion (253) formed at one end of the second member (200) is formed so as to be in contact with at least a portion of the first other end portion (102), and the third facing portion (353) is formed so as to be in contact with at least a portion of the other end portion of the second member (200). The first member (100), the second member (200), and the third member (300) are formed to be in contact and can be fitted.

Here, the first facing portion (153) is formed to be in contact with the second end portion (201), and the second facing portion (253) formed on the second end portion (201) is formed to be in contact with the first other end portion (102) and can be fitted together. For example, the first facing portion (153) and the second facing portion (253) having a thickness equal to half the thickness of the first member (100) and the second member (200) can be fitted together. Specifically, each member formed as a circular bar can be fitted together by the first facing portion (153) and the second facing portion (253) so that the central axis does not shake.

In addition, the second facing portion (253) may be formed on the second end portion (201) and the second other end portion (202) of the second member (200), respectively, and the second facing portion (253) formed on the second end portion (201) may be formed to be in contact with the first other end portion (102), and the second facing portion (253) formed on the second other end portion (202) may be formed to be in contact with the third end portion (301), such that the first member (100), the second member (200), and the third member (300) may be respectively fitted.

In addition, the third facing portion (353) may be formed on the third end portion (301) of the third member (300) and formed to be in contact with the second end portion (202) so that the second member (200) and the third member (300) are fitted together.

At this time, the first facing portion (153), the second facing portion (253), and the third facing portion (353) may all have the same thickness. Accordingly, when the first member (100), the second member (200), and the third member (300) are fitted together, they may be welded together without any protruding portions on the inside or outside of the ring.

According to one embodiment of the present invention, the first facing portion (153) and the second facing portion (253) may be formed to be in contact, and the second facing portion (253) and the third facing portion (353) may be formed to be in contact.

Here, the first facing portion (153) and the second facing portion (253) may have a protruding shape, and the protruding portions may be in contact with each other so as to be interlocked and contact each other without a gap.

In addition, the second facing portion (253) and the third facing portion (353) may have a protruding shape, and the protruding portions may be in contact with each other so as to be interlocked and contact each other without a gap.

The first facing portion (153), the second facing portion (253), and the third facing portion (353) having this form do not form a spaced gap, thereby increasing durability during welding and preventing weakening of strength due to the gap.

According to one embodiment of the present invention, the first facing portion (153) may include a first concave portion (154) formed in a 'v' shape by missing at least a portion of an upper end, the second facing portion (253) may include at least one second concave portion (254) formed in a 'v' shape by missing at least a portion of a lower end, and the third facing portion (353) may include a third concave portion (354) formed in a 'v' shape by missing at least a portion of an upper end.

Here, the first concave portion (154), the second concave portion (254), and the third concave portion (354) may have a shape in which at least some of the first member (100), the second member (200), and the third member (300) are missing.

Specifically, the first concave portion (154) may have a shape in which the other end of the first facing portion (153) and one end of the second end portion (201) are detached, respectively.

At this time, the dropped shape may be a 'v' shape and may have a size that can be visually confirmed from the outside or inside.

In addition, the second concave portion (254) may be formed in multiple portions on at least one of the second end portion (201) and the second end portion (202) of the second member (200).

Specifically, the second concave portion (254) can be formed at the end and middle portion of the second end portion (201) and the end and middle portion of the second other end portion (202), as shown in FIGS. 14 and 15.

In addition, the third concave portion (354) may be formed at the upper end of the third end portion (301) of the third member (300). At this time, the third concave portion (354) may have a shape in which a part of it is missing, and may have a shape in which a part of the upper side of the second end portion (202) is missing together. Here, the missing shape may be a 'v' shape.

According to one embodiment of the present invention, one of the second concave portions (254) may be formed at a position perpendicular to the first concave portion (154), and one of the second concave portions (254) may be formed at a position perpendicular to the third concave portion (354).

Here, the first concave portion (154) may be formed at the upper end of the first end portion (102), and one of the second concave portions (254) may be formed at a position perpendicular to the first concave portion (154) (lower side of the second end portion (201)).

Additionally, the third concave portion (354) may be formed at the upper end of the third end portion (301), and one of the second concave portions (254) may be formed at a position perpendicular to the third concave portion (354) (lower side of the second end portion (201)).

By using this second concave portion (254), the first concave portion (154) or the third concave portion (354) can be easily confirmed from the outside of the rotor shaft (10).

According to one embodiment of the present invention, welding can be performed from a second concave portion (254) formed at a position perpendicular to the first concave portion (154) to the first facing portion (153), and welding can be performed from a second concave portion (254) formed at a position perpendicular to the third concave portion (354) to the third facing portion (353).

Here, the first concave portion (154) and the third concave portion (354) are formed on the inside of the rotor shaft (10), so they may not be visible from the outside. In addition, for welding, welding must be performed inside the hollow portion (400) of the rotor shaft (10), but this may be inefficient in terms of cost and time. Accordingly, the first concave portion (154) and the third concave portion (354) may be welded on the outside of the rotor shaft (10).

For example, when a second concave portion (254) formed at a position perpendicular to a first concave portion (154) is welded with strong heat, the first concave portion (154) formed inside the rotor shaft (10) may be welded together. In addition, when a second concave portion (254) formed at a position perpendicular to a third concave portion (354) is welded with strong heat, the third concave portion (354) formed inside the rotor shaft (10) may be welded together.

When welding using this method, the first facing portion (153) formed on the inside of the rotor shaft (10) can be welded with minimal cost and time.

According to one embodiment of the present invention, the first facing portion (153) region and the third facing portion (353) region can be TIG welded, and the second facing portion (253) region can be laser welded.

Here, TIG (tungsten inert gas) welding can be welding using tungsten inert gas. Another expression is GTAW (gas tungsten arc welding), and it can be a welding method using a non-consumable tungsten electrode with the highest melting point among metals. The welding area can be protected with an inert gas that does not mix well with other elements such as argon/helium. The principle can be to generate an arc between a non-consumable tungsten electrode and a support material and weld the base material with the arc heat.

Additionally, laser welding can be used to melt and weld materials using a laser-focused heat source. It can exhibit superior performance in terms of speed compared to other welding methods.

The second concave portion (254) formed at the end of the second end portion (201), which is the second facing portion (253) area, may be welded by TIG welding from the outside of the rotor shaft (10). (TIG welding is possible because the second facing portion (253) protrudes outward.)

In addition, since the first facing portion (153) area is formed on the inside of the rotor shaft (10), laser welding may be performed so that welding can be performed from the outside. For example, the entire thickness of the second main body (210) may be melted and welded using the high temperature of laser welding.

According to one embodiment of the present invention, the area where the first facing portion (153) and the second facing portion (253) are in contact and the area where the second facing portion (253) and the third facing portion (353) are in contact may be friction-welded.

Here, the area where the first facing portion (153) and the second facing portion (253) come into contact may mean the area where the first fitting portion (150) and the second fitting portion (250) come into contact when fitted together.

These areas may be friction welded by utilizing the heat of frictional force generated by the rotation of the first member (100) and the second member (200).

In addition, the area where the second facing portion (253) and the third facing portion (353) come into contact may mean the area where the second fitting portion (250) and the third fitting portion (350) come into contact when fitted together.

These areas may be friction welded by utilizing the heat of frictional force generated by the rotation of the second member (200) and the third member (300).

The welding methods described above can be used singly or in combination.

According to one embodiment of the present invention, the concave portion can receive a bead generated by welding the facing portion, or guide the position of the facing portion.

Specifically, the first facing portion (153) and the third facing portion (353) formed on the inside of the rotor shaft (10) may not be visible to the naked eye from the outside. Accordingly, welding may be impossible.

These first facing portion (153) and third facing portion (353) can be guided by at least one of the second concave portions (254).

For example, the part where the first facing portion (153) and the second end portion (201) come into contact may be guided by a second concave portion (254) located in an area perpendicular to the first facing portion (153).

Additionally, the part where the third facing portion (353) and the second end portion (202) come into contact may be guided by a second concave portion (254) located in an area perpendicular to the third facing portion (353).

According to one embodiment of the present invention, the first member (100) may be provided by processing the inner and outer surfaces of a circular bar, the second member (200) may be provided as a circular bar, and the third member (300) may be provided by processing the inner and outer surfaces of the circular bar.

Here, the round bar may mean a round and long stick. In the present invention, it may be a round bar with a hollow portion (400) formed inside.

The first member (100), the second member (200), and the third member (300) have different uses and different shapes. Accordingly, they may be processed separately and then welded to form an integrated structure.

For example, the first member (100) may be formed so that the radius of the hollow portion (400) becomes smaller as it goes toward the first end (101), the second member (200) may be formed so that the radius of the hollow portion (400) is the same, and the third member (300) may be formed so that the radius of the hollow portion (400) becomes smaller as it goes toward the third end (302).

In this way, the first member (100), the second member (200), and the third member (300) having different shapes may be formed into one piece by processing the inner and outer sides, respectively.

According to one embodiment of the present invention, a portion where the first fitting part (150) and the second fitting part (250) come into contact and an area where the second fitting part (250) and the third fitting part (350) come into contact may be a bead generating part (1000i, 1000j) where beads are generated.

Here, the bead generating portion (1000i, 1000j) may refer to a bead generated by friction welding, but is not limited thereto. It may include a bead generated by TIG welding or laser welding.

Additionally, beads generated from the bead generating portion (1000i, 1000j) may be received in the concave portion (154, 254, 354).

The concave portion (154, 254, 354) may have a shape in which a portion of the facing portion is removed, and accordingly, when a bead generated from the bead generating portion (1000i, 1000j) protrudes outward through the facing portion, the bead may be positioned in the concave portion (154, 254, 354) to minimize the bead protruding outward.

A method (S10) for manufacturing a rotor shaft (10) according to one embodiment of the present invention may include a material cutting step (S100). The material cutting step (S100) may be a step of cutting a circular bar to prepare a first circular bar that becomes a material of a first member (100), a second circular bar that becomes a material of a second member (200), and a third circular bar that becomes a material of a third member (300). The length of the first circular bar may be cut to have a length that is equal to the first length (L1) with a length that is equal to the second length (L2) and the third length (L3) with a length that is equal to the third length (L3). The third circular bar may be cut to have a length that is equal to the fourth length (L4).

A method (S10) for manufacturing a rotor shaft (10) according to one embodiment of the present invention may include a material forming step (S200). For example, the material forming step (S200) may be a step of processing an outer surface or an inner surface of a first circular bar and a third circular bar prepared in the material cutting step (S100). The first circular bar may be processed to form a first member (100). The third circular bar may be processed to form a third member (300). A fitting part may be formed in the material forming step (S200). The fitting part may include a first fitting part, a second fitting part (250), and a third fitting part (350).

Additionally, the first fitting portion may be formed by any one of the first guide portion (151), the first inclined portion (152), the first facing portion (153), and the first concave portion (154).

Additionally, the second fitting portion (250) may be formed by any one of the second guide portion (251), the second inclined portion (252), the second facing portion (253), and the second concave portion (254).

Additionally, the third fitting portion (350) may be formed by any one of the third guide portion (351), the third inclined portion (352), the third facing portion (353), and the third concave portion (354).

A method (S10) for manufacturing a rotor shaft (10) according to one embodiment of the present invention may include a friction welding step (S300). In the friction welding step (S300), a first bead (130) and a second bead (230) may be formed at a joint between a first member (100) and a second member (200). In addition, a second bead (230) and a third bead (330) may be formed at a joint between a second member (200) and a third member (300).

A method (S10) for manufacturing a rotor shaft (10) according to one embodiment of the present invention may include a post-processing step (S400). For example, the post-processing step (S400) may be a step of removing beads (130, 230, 330) formed on the inner and outer sides of the first member (100), the second member (200), and the third member (300). The post-processing step (S400) may be a step of removing beads formed at the first joint portion (J1) and the second joint portion (J2).

Although the present invention has been described in detail through specific embodiments, this is intended to specifically explain the present invention, and the present invention is not limited thereto, and it will be apparent that modifications or improvements can be made by those skilled in the art within the technical spirit of the present invention.

All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific protection scope of the present invention will be made clear by the appended claims.

10: Rotor shaft
100: 1st absence 101: 1st first part 102: 1st other part
110: 1st body 120: 1st hollow 130: 1st bead
150: 1st fitting part 151: 1st guide part 152: 1st slope part
153: First surface 154: First concave surface
200: Second absence 201: Second first part 202: Second other end
210: Second body 220: Second hollow 230: Second bead
231: Second single-sided bead 232: Second other-sided bead 250: Second fitting
251: 2nd guide section 252: 2nd slope section 253: 2nd facing section
254: Second concave
300: Third Absence 301: Third First Part 302: Third Second Part
310: Third main body 320: Third hollow 330: Third bead
350: Third alignment part 351: Third guide part 352: Third slope part
353: Third face 354: Third concave
400: The Central Department
1000: Bead generating part L1: First length L2: Second length
L3: Third length L2: Fourth length J1: First joint
J2: Second joint H1: First tolerance H2: Second tolerance
H3: Third tolerance CL: Center line

Claims (8)

A first member having a length;
A second member having a length and one side of which is friction-welded to the other side of the first member; and
A third member having a length and one side of which is friction-welded to the other side of the second member;
The first to third members each have a fitting portion including at least one inclined portion to enable fitting,
The first absence above is,
A first inclined portion is provided with a cross-section having a tapered shape at the first end,
The second absence above is,
A second inclined portion is provided with a tapered cross-section at the second end and the second end,
The third absence is,
A third inclined portion is provided with a third end portion having a tapered cross-section,
The second inclined portion formed on the first inclined portion and the second member end are fitted so that at least a portion thereof is in contact with each other, and the second inclined portion and the third inclined portion formed on the second member end are fitted so that at least a portion thereof is in contact with each other.
When the first inclined portion and the second inclined portion formed at one end of the second member are fitted together,
forming a tolerance between the first member and the second member, at least a portion of which is spaced apart;
Rotor shaft.
delete delete In the first paragraph,
When the second inclined portion and the third inclined portion formed at the other end of the second member are fitted together,
By contact between the second inclined portion and the third inclined portion, a tolerance is formed between the second member and the third member, with at least a portion thereof being spaced apart.
Rotor shaft.
In the first paragraph,
The inclination angles of the first inclined portion and the second inclined portion formed on the second member are the same,
The inclination angles of the second slope portion and the third slope portion formed on the second absence end are the same.
Rotor shaft.
In the first paragraph,
The inclination angles of the first inclined portion and the second inclined portion formed on the second member are different,
The inclination angles of the second slope portion and the third slope portion formed on the second absence end are different.
Rotor shaft.
In Article 6,
The above first absence is,
It is provided by processing the inner and outer surfaces of the ring,
The second absence above is,
Equipped with a return gift,
The third absence is,
It is provided by processing the inner and outer surfaces of the ring.
Rotor shaft.
In the first paragraph,
The above tolerance is,
A receiving space is formed to receive beads generated from the bead generating portion.
Rotor shaft.