KR20200034486A - Motor and Manufacturing method of the same - Google Patents

Abstract

A motor according to an embodiment of the present invention includes: a rotary shaft; a rotor mounted on the rotary shaft; a stator surrounding the outer circumference of the rotor; an impeller mounted apart from the rotor on the rotary shaft; a bearing housing; and a gas bearing disposed at the bearing housing. The gas bearing includes: a bush unit which has an inner circumferential surface surrounding the outer circumferential surface of the rotary shaft and has one end and the other end spaced apart from each other in the circumferential direction; a plurality of protrusions protruding integrally from the outer surface of the bush unit and coming in contact with the inner circumferential surface of the bearing housing; and a coating layer coated on the inner circumferential surface of the bush unit and having a bearing gap with the outer circumferential surface of the rotary shaft.

Description

Motor and manufacturing method of the same

The present invention relates to a motor and its manufacturing method, and more particularly, to a motor having a bearing and its manufacturing method.

The motor may be installed in a household appliance such as a vacuum cleaner, and in this case, a driving force that draws air into the dust collecting portion may be generated.

An example of such a motor may include a motor housing, a stator installed in the motor housing, a rotor rotated by the stator, and a rotating shaft on which the rotor is mounted. The rotating shaft of the motor may be rotatably supported by at least one bearing, and the rotating shaft may be rotated at a high speed while being supported by the bearing.

The at least one bearing installed on the motor may be a journal bearing such as a foil air bearing that supports the rotating shaft in the radial direction. As such, an example of a motor in which the journal bearing supports the rotating shaft in the radial direction is disclosed in Korean Patent Publication 10--10. 2018-0069490 A (June 25, 2018).

The journal bearing disclosed in Republic of Korea Patent Publication No. 10-2018-0069490 A includes a bump foil disposed inside a hollow cylindrical bearing housing and a top foil disposed inside the bump foil, and the bump foil has a plurality of convex floor portions And a valley portion located between each floor portion, and the bump foil may be elastically deformed by a radial load of the rotating shaft.

The above-described motor may be mounted after each of the bump foil and the top foil is manufactured, and then the bump foil and the top foil may be inserted into and mounted in the bearing housing. The assembly process of the bump foil and the top foil is complicated, and the bottom and valley portions of the bump foil are complicated. There is a problem in that the processing cost for formation is large.

Republic of Korea Patent Publication No. 10-2018-0069490 A (June 25, 2018)

The present invention has an object to provide a motor and its manufacturing method that can minimize the number of parts, and are easy to assemble and manufacture.

A motor according to an embodiment of the present invention includes a rotating shaft; A rotor mounted on the rotating shaft; A stator surrounding the outer circumference of the rotor; An impeller mounted spaced apart from the rotor on the rotating shaft; A bearing housing; It includes a gas bearing disposed in the bearing housing, the gas bearing includes a bush portion having one end and the other end surrounding the outer circumferential surface of the rotating shaft and spaced apart in the circumferential direction; A plurality of protrusions integrally projecting from the outer surface of the bush portion and contacting the inner circumferential surface of the bearing housing; It is coated on the inner circumferential surface of the bush portion and includes a coating layer having an outer circumferential surface of the rotating shaft and a bearing gap.

A passage through which air can pass may be formed between a pair of protrusions adjacent to the outer surface of the bush portion and the inner surface of the bearing housing.

The plurality of protrusions may gradually move away from other protruding protrusions toward the outside.

The thickness of the projection may be thicker than the thickness of the bush.

The protrusion may have a rectangular cross-sectional shape.

The thickness of the projections can be thicker than the bearing clearance.

The arc length of the bushing may be shorter than the circumferential length of the inner circumference of the bearing housing.

Method of manufacturing a motor according to an embodiment of the present invention comprises the steps of forming a plate with a plurality of protrusions protruding from one surface with a polymer; Coating a coating layer on opposite sides of one surface on which the plurality of protrusions protrude from both sides of the plate; Manufacturing a gas bearing by rolling the plate in an arc shape such that the plurality of protrusions are located on the outside and the coating layer is located on the inside; Inserting the gas bearing into a bearing housing; And passing a rotating shaft inside the gas bearing.

According to an embodiment of the present invention, the protrusion is formed to protrude from the bush portion and the coating layer is coated on the inner circumferential surface of the bush portion, so that the number of parts of the gas bearing can be minimized and the assembly process of the gas bearing can be simplified.

In addition, a pair of protrusions adjacent to the outer surface of the bush portion and a passage through which air passes through the inner surface of the bearing housing are formed, so that the heat of the coating layer can be transferred to the air passing through the passage through the bush portion, so that the coating layer can be rapidly cooled. have.

In addition, the plurality of protrusions are formed to gradually move away from other protruding protrusions toward the outside direction, so that sufficient flow paths for air to pass between the adjacent pair of protrusions can be formed, and a large amount of air is formed between the pair of protrusions. The gas bearing can be dissipated while passing through.

In addition, it is possible to minimize damage to the rotating shaft, which may occur when the thickness of the projection is thin.

In addition, it is possible to minimize the overlap of a part of the bush in the radial direction, and the dispersion of the bearing gap can be minimized.

In addition, since the coating layer is formed on the opposite side of one surface of the plate where the protrusion protrudes, the coating layer can be coated as evenly as possible, and dispersion of the bearing gap can be minimized.

In addition, since the gas bearing is made of an elastic polymer, the shock that may occur when the rotating shaft strikes the gas bearing can be absorbed by the gas bearing, and the gas bearing is a bearing by a simple operation of inserting the gas bearing into the bearing housing. Mounting to the housing can be completed.

1 is a side view of a motor according to an embodiment of the present invention,
2 is a cross-sectional view of a motor according to an embodiment of the present invention,
3 is an exploded perspective view of a motor according to an embodiment of the present invention,
Figure 4 is a cross-sectional view of the rotor assembly according to an embodiment of the present invention,
5 is an enlarged perspective view showing a gas bearing according to an embodiment of the present invention,
6 is a flowchart illustrating a method of manufacturing a motor according to an embodiment of the present invention,
7 is a perspective view of a plate according to an embodiment of the present invention before it is dried in an arc shape;
8 is a cross-sectional view when the gas bearing shown in FIG. 5 is inserted inside the bearing housing,
9 is a cross-sectional view when the rotating shaft penetrates into the gas bearing shown in FIG. 8.

Hereinafter, a specific embodiment of the present invention will be described in detail with the accompanying drawings.

1 is a side view of a motor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a motor according to an embodiment of the present invention, FIG. 3 is an exploded perspective view of a motor according to an embodiment of the present invention, and FIG. 4 is a A cross-sectional view of a rotor assembly according to an embodiment of the invention, Figure 5 is an enlarged perspective view of a gas bearing according to an embodiment of the present invention.

The motor includes a rotating shaft 1; A rotor 2 mounted on the rotating shaft 1; A stator 3 surrounding the outer circumference of the rotor 2; An impeller 4 mounted spaced apart from the rotor 2 on the rotating shaft 1; A bearing housing 5; It can include a gas bearing (7) disposed in the bearing housing (5). In addition, the motor may further include a motor body 8 forming an exterior.

An impeller space S1 in which the impeller 4 is accommodated may be formed inside the motor body 8. In addition, a motor space S2 in which the rotor 2 and the stator 3 are accommodated may be formed inside the motor body 8.

A suction port 91 through which air is sucked into the impeller space S1 may be formed in the motor body 8. In addition, an outlet 101 through which air in the motor space S2 is discharged to the outside of the motor may be formed in the motor body 8.

The motor body 8 may be formed of a single member, or may be composed of a combination of a plurality of members.

When the motor body 8 is a combination of a plurality of members, the motor body 8 may include an inlet body 9 and a motor housing 10.

The inlet body 9 may be formed with a suction port 91 through which air is sucked. The inlet body 9 may be arranged to surround the outer circumference of the impeller 4. Inside the inlet body 9, an impeller space S1 in which the impeller 4 is rotatably received may be formed.

The inlet body 9 may be coupled to the motor housing 10 on the opposite side of the intake 91. The inlet body 9 may surround all or a part of the outer circumference of the motor housing 10.

The motor housing 10 may surround the outer circumference of the stator 3. A motor space S2 in which the rotating shaft 1 and the rotor 2 and the stator 3 are accommodated may be formed inside the motor housing 10. The motor housing 10 may be formed with a discharge port 101 through which the air flowing into the motor space S2 after flowing by the impeller 4 is discharged to the outside of the motor body 8. The discharge port 101 may be formed on the opposite side of the suction port 91.

The motor housing 10 may be hollow. In the motor of this embodiment, the rotating shaft 1 is not supported by the motor housing 10, and the motor housing 10 may not include a separate rotating shaft supporter for supporting the rotating shaft 1.

The rotating shaft 1 may be disposed to extend from the motor space S2 to the impeller space S1. One end 1A of the rotation shaft 1 may be located in the motor space S2, and the other end 1B of the rotation shaft 1 may be located in the impeller space S2.

One end 1A of the rotating shaft 1 may be close to the rotor 2 of the rotor 2 and the impeller 4, and may be a free end on the rotor side.

The other end 1B of the rotating shaft 1 may be closer to the impeller 4 of the rotor 2 and the impeller 4, and may be an impeller-side free end.

Referring to FIG. 2, the rotating shaft 1 may include an impeller coupling portion 16 to which the impeller 4 is coupled, and a rotor coupling portion 17 to which the rotor 2 is coupled. In addition, the rotation shaft 1 may further include a support portion 19 (see FIG. 2) supported by the gas bearing 7.

The impeller coupling portion 16 may constitute a small diameter portion 12 (refer to FIG. 4), which will be described later.

The rotor coupling portion 17 may constitute a large diameter portion 11 (see FIG. 4), which will be described later.

The support portion 19 may be a portion at least a portion of which is directed to the gas bearing 7 in the radial direction R. The support part 19 may be located between the rotor coupling part 17 and the impeller coupling part 16. The rotating shaft 1 may be in the order of the rotor engaging portion 17, the supporting portion 19 and the impeller engaging portion 16 in the axial direction (L).

Referring to FIG. 4, the rotating shaft 1 may include a large diameter portion 11 and a small diameter portion 12. The large-diameter portion 11 and the small-diameter portion 12 may be continuous in the axial direction. The small diameter portion 12 may be a portion having a smaller diameter than the large diameter portion 11.

The large diameter portion 11 is a portion to which the rotor 2 is mounted, and its outer diameter may be larger than the outer diameter of the small diameter portion 12. The large-diameter portion 11 may include one end 1A of the rotating shaft 1. The large diameter portion 11 may be located in the motor space (S2).

The large diameter portion 11 may include a rotor coupling portion 17 to which the rotor 2 is coupled. The outer circumferential surface of the rotor coupling portion 17 may be surrounded by the rotor 2. The rotor coupling portion 17 may include one end 1A of the rotating shaft 1.

The small-diameter portion 12 is a portion on which the impeller 4 is mounted, and may extend in the axial direction from the axial end 11A of the large-diameter portion 11. The small diameter portion 12 may penetrate the through hole H of the bearing housing 5. The small diameter portion 12 may include the other end 1B of the rotating shaft 1. A portion of the small diameter portion 12 may be located in the motor space S1, and the rest of the small diameter portion 12 may be located in the impeller space S1. As illustrated in FIG. 4, the small diameter portion 12 may further include an impeller coupling portion 16 to which the impeller 4 is coupled.

The small diameter portion 12 may face the gas bearing 7 in the radial direction R.

The rotor 2 can be mounted on the rotating shaft 1. The rotor 2 may be arranged to surround the outer circumference of the rotating shaft 1. The rotor 2 may be mounted in a portion accommodated in the motor space S2 of the rotating shaft 1.

The rotor 2 may be spaced apart from the gas bearing 7 in the axial direction L.

The rotor 2 may include a magnet 21. The rotor 2 may further include a magnet core 22 on which the magnet 21 is mounted. The rotor 2 may further include a pair of end plates 23 and 24 spaced apart in the axial direction L.

The rotor 2 may constitute the rotor assembly A together with the rotating shaft 1 and the impeller 4.

The rotor 2 may be heavier than the impeller 4. The center of gravity of the rotor assembly A may be closer to the rotor 2 of the impeller 4 and the rotor 2.

2, the stator 3 may be disposed on the inner circumference of the motor body 8. The stator 3 may be disposed on the inner circumference of the motor housing 10. The stator 3 may include a stator core 31 and a coil 32 wound on the stator core.

The impeller 4 may be mounted on the rotating shaft 1. The impeller 4 may be mounted spaced apart from the rotor 2 and the gas bearing 7. The impeller 4 may be spaced apart from each of the gas bearing 7 and the rotor 2 in the axial direction L.

The impeller 4 may be made of a lighter material than the rotor 2, and may be formed of a high-strength synthetic resin material such as PEEK.

The impeller 4 may be a centrifugal impeller that sucks gas such as air in the axial direction L and discharges it in the centrifugal direction R. The impeller 4 may include a hub 42 and a plurality of blades 44 formed on the outer circumference of the hub 42.

The motor may further include a diffuser 46 (see FIGS. 2 and 3) for guiding air flowed from the impeller 4. The diffuser 46 can be located inside the motor body 8, especially the inlet body 9, and its circumference can face the inner circumferential surface of the motor body 8, especially the inlet body 9.

A passage may be formed between the diffuser 46 and the inlet body 9 to guide gas such as air flowed by the impeller 4 to the motor space S2.

The bearing housing 5 can be located between the impeller 4 and the rotor 2. A through hole H through which the rotating shaft 1 passes may be formed in the bearing housing 5. The bearing housing 5 may surround the outer circumference of a part of the rotating shaft 1 (ie, the support portion 19). The bearing housing 5 may surround a part of the outer circumference of the small diameter portion 12 of the rotating shaft 1. The minimum inner diameter of the bearing housing 5 may be larger than the outer diameter of the small diameter portion 12.

The bearing housing 5 may be formed integrally with the motor body 1, or may be manufactured separately from the motor body 1 and then coupled to the motor body 1. When the bearing housing 5 is formed integrally with the motor body 1, the assembly tolerance can be minimized.

When the bearing housing 5 is manufactured separately from the motor body 1, it may be fastened to the motor body 8, in particular, the inlet body 9 or the motor housing 10 with fastening members such as screws.

The bearing housing 5 may include a housing portion 54 (see FIGS. 3 and 4) supporting the gas bearing 7. The bearing housing 5 may further include a fastening portion 55 (see FIG. 3) fastened to the motor body 1. The bearing housing 5 may further include a plurality of bridge portions 56 (see FIG. 3) connecting the housing portion 54 and the fastening portion 55.

The through hole H through which the rotation shaft 1 passes may be formed in the housing part 54. A bearing space in which the humidifying bearing 7 is accommodated may be formed inside the housing part 54.

The gas bearing 7 may be an oilless bearing. The gas bearing 7 may be a bearing having a low friction coating layer 78 (see FIG. 5) having excellent wear resistance. The low friction coating layer 78 may be formed on the inner circumference of the gas bearing 7.

Gas such as air can support the rotating shaft 1 between the low friction coating layer 78 of the gas bearing 7 and the outer circumferential surface of the rotating shaft 1.

The gas bearing 7 may be a dynamic pressure gas bearing, and the rotation shaft 1 may be supported by gas such as air introduced between the inner circumferential surface of the gas bearing 7 and the rotation shaft 1 around the gas bearing 7.

When the rotating shaft 1 is rotated, a velocity component of airflow is generated on the outer circumference of the rotating shaft 1, and the rotating shaft 1 is eccentric toward one side of the gas bearing 7 among the inner positions of the gas bearing 7 Can be located. When the rotating shaft 1 is eccentric, a narrower gap is formed between the rotating shaft 1 and the gas bearing 7 than the bearing gap when the rotating shaft 1 is not eccentric, and is located inside the gas bearing 7 Gas such as air may be sucked toward the narrow gap, and air outside the gas bearing 7 may be drawn between the gas bearing 7 and the rotating shaft 1.

The gas bearing 7 has an inner surface 71 (see FIG. 5) spaced apart from the outer circumferential surface of the rotating shaft 1, and a contact end 72 (FIG. 5) in contact with the bearing housing portion 54 formed in the bearing housing 5 Reference).

The gas bearing 7 may have long slits 73 (see FIG. 5) in the axial direction L on one side. The slit 73 can be opened radially in the gas bearing 7.

The gas bearing 7 includes a bush portion 74 whose inner circumferential surface surrounds the outer circumferential surface of the rotary shaft 1 and has one end 74A and the other end 74B spaced apart in the circumferential direction; It may include a plurality of projections (76) integrally projecting from the outer surface (74D) of the bush portion 74 and contacting the inner circumferential surface of the bearing housing (5).

The gas bearing 7 is capable of absorbing shock when the rotating shaft 1 is in contact with the bush portion 74, but preferably has a material and shape capable of maintaining a state in close contact with the bearing housing 5 as much as possible. .

When the gas bearing 7 is inserted into the bearing housing 5, it is easily inserted into the bearing housing 5 with a part bent, and when it is inserted into the bearing housing 5, before it is inserted into the bearing housing 5 It is desirable to have a restoring force to be restored to the shape of the.

In addition, the gas bearing 7 preferably has a ductility that allows the projection 76 to be pressed flat, and when the rotating shaft 1 is spaced apart from the bush portion 74, the projection 76 is restored to its original shape. , It is preferable that the protrusion 76 has an elastic force capable of pushing the bush 74 in the inner direction in which the rotating shaft 1 is located. In addition, since the weight of the motor increases when the gas bearing 7 is heavy, the gas bearing 7 is preferably formed of a lightweight material.

The preferred material of the gas bearing 7 may be a polymer, and for example, it is preferable to be molded of a synthetic resin such as plastic having elasticity or rubber (natural rubber or synthetic rubber).

The arc length of the bush portion 74 may be shorter than the circumferential length of the inner circumference of the bearing housing 5. If the arc length of the bush portion 74 is equal to the circumferential length of the inner circumferential surface of the bearing housing 5 or longer than the circumferential length of the inner circumferential surface of the bearing housing 5, the bush portion 74 is the peripheral portion of one end 74A. And the periphery of the other end 74B may overlap in the radial direction. In this case, the bearing gap G between the gas bearing 7 and the rotating shaft 1 may be uneven and the dispersion of the bearing gap G may be large. have.

On the other hand, as described above, when the arc length of the bush portion 74 is shorter than the circumferential length of the inner circumference of the bearing housing 5, one end 74A and the other end 74B of the bush portion 74 are circumferential. The spaced apart state can be maintained, and the dispersion of the bearing gap G formed between the gas bearing 7 and the rotating shaft 1 can be minimized.

The thickness of the protrusion 76 (the width protruding from the bush portion 74, see FIG. 9) may be thicker than the thickness of the bush portion 74 (see T2, FIG. 9). The protrusion 76 is a portion pressed by the bush 74 when the portion surrounded by the gas bearing 7 of the rotating shaft 1 is eccentric, but if the thickness is too thin, it may not sufficiently absorb the impact. have.

When the rotating shaft 1 hits the bush portion 74, the protrusion 76 preferably has a thickness T1 that can minimize the reaction acting on the rotating shaft 1, and the thickness of the protrusion 76 ( T1) is preferably 1.1 to 6 times the thickness of the bush portion 74 (T2).

The protrusion 76 may have a rectangular cross-sectional shape. When the gas bearing 7 rotates in the circumferential direction inside the bearing housing 5, the outer end of the projection 76 may be worn by the bearing housing 5, and the projection 76 is preferably a bearing housing 5 ). The outer end 76A of the projection 76 may be planar prior to mounting in the bearing housing 5, and when the gas bearing 7 is inserted and mounted in the bearing housing 5, the outside of the projection 76 The end 76A may be deformed into a curved shape to match the inner circumferential surface shape of the bearing housing 5, and the protrusion 76 may be in a state where the outer end 76A is in surface contact with the inner circumferential surface of the bearing housing 6. Can be maintained.

The protrusion 76 may have a rectangular parallelepiped shape.

The projection 76 may be pressed in a flat shape by an external force acting on the rotating shaft 1 from the bush 74, and when the external force acting on the bush 74 is removed, it may be restored to its original shape.

The plurality of protrusions 76 may gradually move away from other protruding protrusions toward the outside. The plurality of protrusions 76 may be parallel to adjacent rudders prior to being mounted on the bearing housing 5, but the bush portion 74 may gradually move away from adjacent rudders as it goes outward as it deflects in an arc shape.

The thickness T2 of the projection 76 may be thicker than the bearing gap G.

The gas bearing 7 may further include a coating layer 78 (see FIG. 5) coated on the inner circumferential surface 74C of the bush portion 74 and having an outer circumferential surface of the rotating shaft 1 and a bearing gap G. have.

The coating layer 78 may be polytetrafluoroethylene (PTFE), diamond like carbon (DLC), lubrite, Mos2, D10, boron nitride, ceramic powder, soft metal such as soap or copper or lead.

The inner surface 71 of the gas bearing 7 may be a surface facing the outer circumferential surface of the rotating shaft 1 among the coating layers 78.

The coating layer 78 may be applied to one surface of the plate when the gas bearing 7 is in a plate-chain state before being dried in a friendly shape or a ring shape, in which case the thickness uniformity of the coating layer 78 becomes high, and the gas bearing (7) may be easy to manage the thickness distribution as a whole.

Manufacturing and mounting of the gas bearing 7 will be described later with reference to FIGS. 6 to 9.

Meanwhile, the gas bearing 7 may support the rotation shaft 1 together with the sub bearing 6 (see FIGS. 2 to 4).

The sub bearing 6 may be either a gas bearing, a magnetic bearing, or a rolling bearing.

When the sub-bearing 6 is a rolling bearing, the sub-bearing 6 can support the rotating shaft 1 in a state where the rotating shaft 1 is defective, and when the rotating shaft 1 is stationary or low speed, the sub-bearing ( 6) can support the rotating shaft 1 in both directions of the axial direction (L) and the radial direction (R), and the gas bearing (7) has a sub-bearing (6) the rotating shaft (1) in the axial direction (L) Because it is supported by, it can be composed of a radial gas bearing, and in particular a journal gas bearing.

Hereinafter, the sub-bearing 6 will be described as being a rolling bearing and will be described using the same reference numerals for convenience of explanation. However, it is needless to say that the sub-bearing 6 of the present embodiment is not limited to a rolling bearing, but may be composed of a magnetic bearing or the like.

An example of the rolling bearing 6 is coupled to the support 19 and it is possible to support the support 19 together with the gas bearing 7. In this case, the rolling bearing 6 can be coupled to the bearing housing 5, and the gas bearing 7 and the rolling bearing 6 are arranged spaced apart in the axial direction in one bearing housing 5, The support portion 19 can be supported together.

As described above, when the gas bearing 7 and the rolling bearing 6 support the support portion 19, each of the one end 1A of the rotating shaft 1 and the other end 1B of the rotating shaft 1 is a motor body 8 ) And a free end that is not supported by the bearing housing 5. The rotating shaft 1 has a support 19 between the one end 1A and the other end 1B, in particular, between the rotor joint 17 and the impeller joint 16, the gas bearing 7 and the rolling bearing 6 Can be supported by.

As described above, if the support 19 is supported by the gas bearing 7 and the rolling bearing 6, the resistance and noise will be reduced than if the support 19 is supported by the pair of rolling bearings 6 It is possible to more stably support the rotating shaft 1 rotating at high speed.

On the other hand, another example of the rolling bearing 6 is the rolling bearing 6 and the gas bearing 7 are located with the rotor 2 interposed therebetween, and the rolling bearing 6 is in the axial direction L with the rotor 2. It is possible to be spaced apart. That is, it is possible to be arranged in the order of the rolling bearing 6, the rotor 2 and the gas bearing 7 in the axial direction. In this case, the rolling bearing 6 can be coupled to a portion located between one end 1A of the rotating shaft 1 and the rotor 2 of the rotating shaft 1, and the motor 8, in particular, the motor housing 10 ).

Hereinafter, for convenience, an example in which the rolling bearing 6 supports the support portion 19 together with the gas bearing 7 will be described in more detail.

The rolling bearing 6 may include an inner ring 61 fixed to the rotating shaft 1, an outer ring 62 and a rolling member 63, as shown in FIG. 4.

The rolling bearing 6 may be a contact bearing that supports the rotating shaft 1 in a state of constant contact with the rotating shaft 1, and may have a higher load bearing capacity than the gas bearing 7.

The rolling bearing 6 can form part of the rotor assembly A when combined with the rotating shaft 1.

When the rolling bearing 6 is mounted on the bearing housing 5 together with the gas bearing 7, the rolling bearing 6 is to be located between the gas bearing 7 and the rotor 2 in the axial direction L. You can.

The rolling bearing 6 may be closer to the rotor 2 of the rotor 2 and the impeller 4. When the rotor 3 and the impeller 4 are mounted on the rotating shaft 1, the center of gravity of the assembly A of the rotating shaft 1, the rotor 3, and the impeller 4 is the rotor 3 than the impeller 4 ).

The inner ring 61 of the rolling bearing 6 may be coupled to the small diameter portion 11 or to the large diameter portion 12. When coupled to the small diameter portion 11, the size of the rolling bearing 6 may be small. have.

The gas bearing 7 may be arranged to face either the small diameter portion 11 or the large diameter portion 12, the gas bearing 7 has a small diameter portion 11 or a large diameter portion 12 and an appropriate bearing gap G ).

The gas bearing 7 preferably forms a sufficient flow path through which gas such as air can support the rotating shaft 1, and this flow path can be determined by the area of the inner surface 71 of the gas bearing 7.

Assuming that the area of the inner surface 71 of the gas bearing 7 is constant, when the diameter of the inner surface 71 of the gas bearing 7 is small, the length of the axial direction L of the gas bearing 7 must be long, and the gas When the diameter of the inner surface 71 of the bearing 7 is large, the length of the axial direction L of the gas bearing 7 may be short.

When the gas bearing 7 faces the small diameter portion 11, the bearing gap G may be between the gas bearing 7 and the small diameter portion 11, and the diameter of the gas bearing 7 is small and the gas bearing 7 ) May be long in the axial direction L.

On the other hand, when the gas bearing 7 faces the large-diameter portion 12, the bearing gap G may be the gas bearing 7 between the large-diameter portions 12, and the diameter of the gas bearing 7 is large and gas The length of the bearing 7 in the axial direction L may be short.

That is, when it is desired to shorten the axial length of the motor, it is preferable that the gas bearing 7 faces the large-diameter portion 12.

On the other hand, when the rolling bearing 6 is coupled to the small diameter portion 12, it is possible that the rolling bearing 6 is supported in the axial direction L by the rotating shaft 1.

The outer diameter of the axial end 11A of the large-diameter portion 11 may be larger than the inner diameter of the inner ring 61 of the rolling bearing 6. In this case, the inner ring 61 of the rolling bearing 6 may be hung on one end 11A of the large-diameter portion 11 in the axial direction L. The axial end 11A of the large-diameter portion 11 may be in contact with the inner ring 61 of the rolling bearing 6, and the rolling bearing 6 is hung at the axial end 11A of the large-diameter portion 11 and the rotor (2) Does not slip toward.

 Meanwhile, the rotating shaft 1 may further include a spacer 20 separating the rolling bearing 6 and the rotor 2. The spacer 20 may include an axial end 11A of the large diameter portion 11. The spacer 20 may have an outer diameter having a step with the small diameter portion 12. The spacer 20 may have an outer diameter having a step with the rotor coupling portion 17.

The spacer 20 may include a locking jaw in which the inner ring 61 of the rolling bearing 6 is axially caught, and this locking jaw is between the inner ring 61 and the rotor 2 of the rolling bearing 6. It can be projected to be located.

When the rolling bearing 6 is coupled to the small-diameter portion 12, and the gas bearing 7 faces the small-diameter portion 12, the small-diameter portion 12 is the inner ring to which the inner ring 61 of the rolling bearing 6 contacts The contact portion 13, the gas bearing 7 toward the radial direction R, the gas bearing facing portion 14, and the impeller 4 may include an impeller coupling portion 16 to which the coupling is performed. In this case, the outer diameter of the inner ring contact portion 13 and the outer diameter of the gas bearing facing portion 14 may be the same.

If the inner ring contact portion 13 and the gas bearing opposing portion 14 have a step difference, the manufacturing process of the rotating shaft 1 may be complicated, whereas, the outer diameter of the inner ring contact portion 13 and the gas bearing opposing portion 14 If the outer diameter of is the same, the manufacturing process of the rotating shaft 1 may be simple.

As shown in FIG. 4, the small diameter portion 12 may further include a connection portion opposing portion 15 that directs the connection portion 53 to be described later of the bearing housing 5 in the radial direction R. An empty space S3 may be formed between the outer circumferential surface of the connecting portion facing portion 15 and the inner circumferential surface of the connecting portion 53. The empty space S3 may function as a passage of air flowing in and out between the inner circumferential surface of the gas bearing 7 and the outer circumferential surface of the rotating shaft 1.

The small diameter portion 12 may have a constant outer diameter from the inner ring contact portion 13 to the impeller engaging portion 16, and in this case, the manufacturing process of the rotating shaft 1 may be simple.

The inner ring contact portion 13, the connection portion opposing portion 15 and the gas bearing opposing portion 14 may constitute a support portion 19. That is, the small-diameter portion 12 may largely include an impeller connection portion 16 and a support portion 19, and the support portion 19 is an inner ring contact portion 13 and a connection portion opposite portion positioned in a line in the axial direction L (15) and a gas bearing facing portion (14).

The small diameter portion 12 may have a constant outer diameter of the support portion 19. In this case, the manufacturing process of the rotating shaft 1 can be simplified.

When the gas bearing 7 is disposed in the bearing housing 5 together with the rolling bearing 6, the housing portion 54 may include a rolling bearing housing portion 51 and a gas bearing housing portion 52. .

The rolling bearing housing part 51 may surround the outer circumferential surface of the rolling bearing 6, and may support and protect the rolling bearing 6. The rolling bearing housing part 51 may face the rotor 2 in the axial direction L.

The outer ring 62 of the rolling bearing 6 may be press-fitted against the inner circumferential surface of the rolling bearing housing part 51 and fixed to the inner circumferential surface of the rolling bearing housing part 51.

The gas bearing housing part 52 may surround the outer circumferential surface of the gas bearing 7, and may support and protect the gas bearing 7. The gas bearing housing part 52 may face the impeller 4 in the axial direction L, as shown in FIG. 2. The gas bearing housing part 52 may be spaced apart from the impeller 4 and the axial direction L, and gas, such as air, is provided between the gas bearing housing part 52 and the impeller 4 to form the gas bearing housing part 52. ) A gap for flowing in and out may be formed. The gap may be in communication between the gas bearing 7 and the rotating shaft 1 between the bearing gap G and the axial direction L.

In the bearing housing 5, a first catching jaw that takes an axial end of the gas bearing 7 may protrude, and a second catching jaw that takes an axial end of the gas bearing 7 may protrude.

The first engaging jaw and the second engaging jaw may protrude to a width that is not worn by the rotating shaft 1 and may protrude to a width that is not in contact with the rotating shaft 1. The protrusion width of each of the first and second locking jaws may be thinner than the thickness of the gas bearing 7. In this case, the outer circumferential surface of the rotating shaft 1 may be in contact with the coating layer 78 of the gas bearing 7, and the wear of the rotating shaft 1 in contact with the first and second locking jaws may be minimized. You can.

The gas bearing housing part 52 may have a smaller inner diameter than the rolling bearing housing part 51. The gas bearing housing part 52 is preferably smaller in size than the rolling bearing 6, and the inner diameter of the gas bearing housing part 52 may be smaller than the inner diameter of the rolling bearing housing part 51.

The bearing housing 5 may further include a connection portion 53. The connection part 53 may be formed by connecting the rolling bearing housing part 51 and the gas bearing housing part 52.

The rolling bearing 6 and the gas bearing 7 are spaced apart in the axial direction L, and the rolling bearing housing part 51 and the gas bearing housing part 52 are also spaced apart, and the connection part 53 is such a rolling bearing housing part. The bearing housing part 51 and the gas bearing housing part 52 can be connected between 51 and the gas bearing housing part 52.

On the other hand, the connecting portion 53 may be formed so that the outer ring 62 of the rolling bearing 6 is in the axial direction (L). The inner diameter of the connecting portion 53 may be smaller than the outer diameter of the outer ring 62 of the rolling bearing 6. The inner diameter of the connecting portion 53 may be smaller than the inner diameter of the rolling bearing housing portion 51 and larger than the inner diameter of the gas bearing housing portion 52.

An empty space S3 may be formed between the inner circumference of the connecting portion 53 and the outer circumferential surface of the rotating shaft 1. The empty space S3 may communicate with the bearing gap G between the gas bearing 7 and the rotating shaft 1 in the axial direction L.

The rolling bearing housing part 51, the gas bearing housing part 52, and the connection part 53 may constitute a housing part 54 for supporting gas bearings 7 and rolling bearings 6 of different types. have.

On the other hand, a passage (see P, FIGS. 4 and 9) through which air passes between the pair of protrusions 76 adjacent to the outer surface 74D of the bush 74 and the inner circumferential surface of the bearing housing 5 is formed. Can be.

When the motor 1 is driven, a part of the air flowing into the motor space S1 by the fan 4 may pass through the passage P and cool the bush portion 74. The heat of the coating layer 78 may be transferred to the passage P through the bush portion 74, and the coating layer 78 may be rapidly cooled. In this embodiment, since only the bush portion 74 is located between the bearing gap G and the passage P, the heat of the coating layer 78 can be transferred to the passage P as quickly as possible, and the gas bearing of this embodiment (7) Instead, the heat can be dissipated more quickly than when the bump foil and the top foil are arranged.

 6 is a flow chart illustrating a method of manufacturing a motor according to an embodiment of the present invention, FIG. 7 is a perspective view when the plate according to an embodiment of the present invention is dried in an arc shape, and FIG. 8 is shown in FIG. 5 9 is a cross-sectional view when the gas bearing is inserted into the bearing housing, and FIG. 9 is a cross-sectional view when the rotating shaft penetrates inside the gas bearing shown in FIG.

The motor manufacturing method of this embodiment largely prepares the gas bearing 7 (S1) (S2) (S3) and, as shown in FIG. 8, the gas bearing 7 is inserted into the bearing housing 5 Step S4; As illustrated in FIG. 9, a step (S5) of passing through the rotation shaft 1 inside the gas bearing 7 may be included.

The steps (S1) (S2) (S3) of preparing the gas bearing 7 include forming a plate 74 'with a plurality of protrusions 76 projecting on one surface (S1, see FIG. 7) with a polymer; A step (S2) of coating the coating layer 78 on the opposite surface 73C of the one surface 74D of the plurality of protrusions 76 protruding from both surfaces 74C and 74D of the plate 74 '; As shown in FIG. 5, the gas bearing 7, as shown in FIG. 5, is rolled in an arc shape with the plate 74 ′ (see FIG. 7) such that a plurality of protrusions 76 are located on the outside and a coating layer 78 is located on the inside. It may include the step of manufacturing (S3).

The thickness T1 of the plate 74 'may be formed thicker than the thickness T2 of the protrusion 76 during the step S1 of forming the plate 74' where the plurality of protrusions 76 protrude.

Step S2 of coating the coating layer 78 may be performed before the plate 74 'is dried in an arc shape, and when the coating layer 78 is coated after being dried in an arc shape, coating of the coating layer 78 The process may be complicated, and the thickness of the coating layer 78 may be uneven and the dispersion of the thickness of the coating layer 78 may be large.

On the other hand, as in the present embodiment, when the coating layer 78 is coated on the plate 74 ', the coating layer 78 may be coated evenly throughout, and the coating layer 78 may be coated with the plate 74'. Even if it is in a shape, the coating layer 78 may be maintained on the inner circumferential surface of the plate 74 '.

The plate 74 'may be rolled to have a radius of curvature, and the radius of curvature may be greater than the radius of the axis of rotation and smaller than the radius of the bearing housing 5.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

1: rotating shaft 2: rotor
3: Stator 5: Bearing housing
7: gas bearing 74: boss
76: projection 78: coating layer

Claims (8)

A rotating shaft;
A rotor mounted on the rotating shaft;
A stator surrounding the outer circumference of the rotor;
An impeller mounted spaced apart from the rotor on the rotating shaft,
A bearing housing;
And a gas bearing disposed in the bearing housing,
The gas bearing
A bush portion having an inner circumferential surface surrounding the outer circumferential surface of the rotating shaft and having one end and the other end spaced apart in a circumferential direction;
A plurality of protrusions integrally projecting from the outer surface of the bush portion and contacting the inner circumferential surface of the bearing housing;
A motor comprising a coating layer coated on the inner circumferential surface of the bush portion and having an outer circumferential surface of the rotating shaft and a bearing gap. According to claim 1,
A motor having a passage through which air passes between a pair of protrusions adjacent to the outer surface of the bush portion and an inner surface of the bearing housing. According to claim 1,
The plurality of protrusions gradually move away from the other protrusions that are turned toward the outside. According to claim 1,
The thickness of the protrusion is greater than the thickness of the bush motor. According to claim 1,
The thickness of the protrusion is a motor thicker than the bearing gap. According to claim 1,
The protrusion is a motor having a rectangular cross-sectional shape. According to claim 1,
The bush length of the bush portion is shorter than the circumferential length of the inner circumference of the bearing housing. Forming a plate with a plurality of protrusions protruding from one surface with a polymer;
Coating a coating layer on opposite sides of one surface on which the plurality of protrusions protrude from both sides of the plate;
Manufacturing a gas bearing by rolling the plate in an arc shape such that the plurality of protrusions are located on the outside and the coating layer is located on the inside;
Inserting the gas bearing into a bearing housing;
Method of manufacturing a motor comprising the step of passing through the rotating shaft inside the gas bearing.

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