JP2012019580A - Electric motor rotor, method for manufacturing electric motor and electric motor rotor and air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor rotor capable of certainly fixing an insulation part arranged between a load side shaft and an anti-load side shaft by a simple method to restrain electric corrosion of a bearing.SOLUTION: In an electric motor rotor of the present invention where a magnet of the rotor and a shaft are integrated by a resin portion formed on a periphery of the shaft and roller bearings are arranged at both axial end faces of the resin portion, the shaft comprises a load side shaft, an anti-load side shaft and a resin insulation part arranged between the load side shaft and the anti-load side shaft.

Description

  The present invention relates to an electric motor rotor using a rolling bearing, and more particularly to an electric motor rotor suitable for an electric motor driven by an inverter. Furthermore, the present invention relates to an electric motor using the rotor of the electric motor, a method for manufacturing the rotor of the electric motor, and an air conditioner equipped with the electric motor.

  Conventionally, when an electric motor is operated using an inverter, the carrier frequency of the inverter is set high for the purpose of reducing the noise of the electric motor that is generated due to switching of the transistors in the power circuit. As the carrier frequency is set higher, the shaft voltage generated on the shaft of the motor based on the high frequency induction increases, and the potential difference existing between the inner ring and the outer ring of the rolling bearing supporting the shaft increases. This makes it easier for current to flow through the rolling bearing. The current flowing through the rolling bearings causes corrosion called electro-corrosion on the rolling surfaces of both the inner and outer ring raceways and the rolling elements (balls and rollers rolling between the inner and outer rings), thereby deteriorating the durability of the rolling bearings. There was a problem.

  Therefore, in order to obtain an electric motor that is easy to assemble with a simple configuration that can prevent electric current from flowing through the rolling bearing provided between the shaft and the motor case and prevent electric corrosion from occurring in the rolling bearing. A stator around which a coil is wound, a frame for fixing the stator, a rotor facing the stator with a slight gap, and the rotor are fixed, and can be freely rotated via a rolling bearing. In an electric motor having a shaft to be supported and a bearing bracket that supports a rolling bearing through an insulating material, the stator core is short-circuited to the bracket via the core connection terminal and the bracket connection terminal, and the static There has been proposed an electric motor having a structure for reducing electric capacity. (See Patent Document 1)

  In addition, the stator including the stator core wound with the winding, the rotating body holding a plurality of permanent magnets in the circumferential direction facing the stator, and the rotating body are fastened so as to pass through the center of the rotating body A motor including a rotor including a fixed shaft, a bearing that supports the shaft, and a bracket that fixes the bearing is provided with a dielectric layer between the shaft and the outer periphery of the rotating body. Has been. (For example, refer to Patent Document 2).

JP 2007-159302 A WO2009 / 113311 A1

  However, the electric motor of Patent Document 1 has a configuration in which the stator iron core is short-circuited with the bracket via the iron core connection terminal and the bracket connection terminal. Therefore, it is necessary to provide a separate connection terminal, which increases the number of parts. There was a problem that the cost would be high.

  Further, since the electric motor of Patent Document 2 has a configuration in which a dielectric layer is provided between the shaft and the rotating body holding the permanent magnet, it is necessary to provide a separate dielectric layer, which increases the number of manufacturing steps. There was a problem that the cost would be high.

  The present invention has been made to solve the above-described problems. In order to suppress the electrolytic corrosion of the bearing, an insulating component provided between the load-side shaft and the anti-load-side shaft of the shaft is simplified. An electric motor rotor, an electric motor, a method for manufacturing the electric motor rotor, and an air conditioner that can be securely fixed by a simple method are provided.

The rotor of the electric motor according to the present invention is an electric motor rotor in which a magnet and a shaft of the rotor are integrated by a resin portion, and rolling bearings are disposed on both end surfaces in the axial direction of the resin portion formed on the outer periphery of the shaft. ,
The shaft includes a load side shaft, an anti-load side shaft, and a resin insulating part provided between the load side shaft and the anti-load side shaft.

  The rotor of the electric motor according to the present invention provides an insulating part made of resin between the load-side shaft and the anti-load-side shaft, thereby preventing the shaft current flowing through the rolling bearing and suppressing electrolytic corrosion. There is an effect to prevent the generation of sound. Moreover, there exists an effect which can fix an insulation component reliably by a simple method.

FIG. 3 shows the first embodiment and is a cross-sectional view of the electric motor 100. FIG. 3 shows the first embodiment and is a cross-sectional view of the mold stator 10. FIG. 3 shows the first embodiment, and is a cross-sectional view showing a state where a rotor 20 is inserted into a mold stator 10. FIG. 5 shows the first embodiment, and is a cross-sectional view of the bracket 30. FIG. 5 shows the first embodiment, and is a perspective view of a stator 40. FIG. 3 shows the first embodiment and is a cross-sectional view of a rotor 20. FIG. 3 shows the first embodiment and is an exploded view of the rotor 20. FIG. 5 shows the first embodiment, and is a cross-sectional view of the rotor resin assembly 20-1. FIG. 5 shows the first embodiment, and is a side view of the rotor resin assembly 20-1 viewed from the load side. FIG. 5 shows the first embodiment and is a front view of a shaft 23; FIG. 5 shows the first embodiment and is an exploded view of the shaft 23. The B section enlarged view of FIG. The A section enlarged view of FIG. FIG. 3 shows the first embodiment and shows the insulating component 26 ((a) is a side view and (b) is a front view). The C section enlarged view of FIG. FIG. 5 shows the first embodiment, and is an enlarged side view of a convex portion 26b of the insulating component 26; The D section enlarged view of FIG. FIG. 4 is a diagram illustrating the first embodiment and is a diagram illustrating a resin magnet 22 of a rotor ((a) is a left side view, (b) is a cross-sectional view taken along line EE of (a), and (c) is a right side view). FIG. 3 is a diagram illustrating the first embodiment and is a diagram illustrating a position detection resin magnet 25 ((a) is a left side view, (b) is a front view, and (c) is an enlarged view of a portion F in (b)). It is a figure shown for a comparison, and sectional drawing (The current path of an axial current is also shown) of the electric motor 400 (it does not use an insulation component) which uses a rotor core. The figure shown for a comparison and the figure which shows the measurement result of the axial current of the electric motor 400. It is a figure shown for a comparison, and sectional drawing (the current path of an axial current is also shown) of the electric motor 500 (it does not use an insulation component) which shape | molds a rotor with resin. The figure shown for a comparison and the figure which shows the measurement result of the axial current of the electric motor. FIG. 3 shows the first embodiment, and is a cross-sectional view of the electric motor 100 (shows a current path of axial current). FIG. 5 shows the first embodiment, and shows the measurement result of the shaft current of the electric motor 100. FIG. FIG. 5 shows the first embodiment, and is a cross-sectional view of a rotor 20a of a first modification. FIG. 5 shows the first embodiment, and is a cross-sectional view of a rotor 20b of a second modification. FIG. 5 shows the first embodiment, and is an exploded view of a shaft 23-2 of a rotor 20b of a second modification. FIG. 5 shows the first embodiment, and is a cross-sectional view of an insulating component 26-1 of a rotor 20b of a second modification. FIG. 5 shows the first embodiment, and is a cross-sectional view of a rotor 20c of a third modification. FIG. 5 shows the first embodiment, and is an exploded view of a shaft 23-3 of a rotor 20c of a third modification. FIG. 10 shows the first embodiment, and is a cross-sectional view of an insulating component 26-2 of the rotor 20c of Modification 3. FIG. 6 shows the first embodiment, and is a cross-sectional view of a rotor 20d of a fourth modification. FIG. 10 shows the first embodiment, and is an exploded view of a shaft 23-4 of a rotor 20d of a fourth modification. FIG. 10 shows the first embodiment, and is a cross-sectional view of an insulating component 26-3 of a rotor 20d according to Modification 4. FIG. 10 shows the first embodiment, and is a cross-sectional view of a rotor 20e of a fifth modification. FIG. 10 shows the first embodiment, and is an exploded view of a shaft 23-5 of a rotor 20e of a fifth modification. FIG. 10 shows the first embodiment, and is a cross-sectional view of an insulating component 26-4 of a rotor 20e of a fifth modification. FIG. 10 shows the first embodiment, and is a cross-sectional view of a rotor 20f of a sixth modification. FIG. 10 shows the first embodiment and is an exploded view of a shaft 23-6 of a rotor 20f according to a sixth modification. FIG. 11 shows the first embodiment and is a cross-sectional view of an insulating component 26-5 of a rotor 20f according to Modification 6. FIG. 5 shows the first embodiment and is a configuration diagram of a drive circuit 200 that drives the electric motor 100; FIG. 5 shows the first embodiment, and shows a manufacturing process of the rotor 20. FIG. 5 shows the second embodiment and is a configuration diagram of an air conditioner 300.

Embodiment 1 FIG.
(Overview)
The electric motor according to the present embodiment is characterized in that the electric corrosion of the bearing can be suppressed. The method for suppressing the electric corrosion of the bearing is to provide an insulating component between the load side rolling bearing arrangement portion and the anti-load side rolling bearing arrangement portion of the shaft. Insulating parts are molded separately, and the insulating parts, magnets (which may include position detection magnets), and shafts (load-side rolling bearing arrangement parts, anti-load-side rolling bearing arrangement parts) are made of resin. The rotor resin assembly is formed by integral molding. Further, the rotor does not use the rotor core in order to suppress the shaft current. A magnet (which may also include a position detection magnet), a shaft (load-side rolling bearing arrangement portion, anti-load-side rolling bearing arrangement portion), and insulating parts are integrally formed of resin. The kind of magnet used is not ask | required.

  Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 shows the first embodiment and is a cross-sectional view of an electric motor 100. An electric motor 100 shown in FIG. 1 includes a mold stator 10, a rotor 20 (defined as a rotor of the electric motor), and a metal bracket 30 attached to one axial end of the mold stator 10. The electric motor 100 is, for example, a brushless DC motor having a permanent magnet in the rotor 20 and driven by an inverter. Other symbols shown in FIG. 1 will be described later.

  FIG. 2 is a diagram showing the first embodiment, and is a cross-sectional view of the mold stator 10. The mold stator 10 is open at one axial end (the right side in FIG. 2), and an opening 10b is formed here. The rotor 20 is inserted from this opening 10b. A hole 11a that is slightly larger than the diameter of the shaft 23 of the rotor 20 is formed in the other axial end portion of the mold stator 10 (left side in FIG. 2). Other configurations of the mold stator 10 will be described later.

  FIG. 3 shows the first embodiment, and is a cross-sectional view showing a state where the rotor 20 is inserted into the mold stator 10. The rotor 20 inserted from the opening 10b (see FIG. 2) at one axial end of the mold stator 10 has a load side shaft 23a in the hole 11a at the other axial end of the mold stator 10 (see FIG. 2). To the outside (left side of Fig. 3). Then, the load-side rolling bearing 21 a (an example of a rolling bearing) of the rotor 20 is pushed in until it comes into contact with the bearing support portion 11 at the axial end portion on the side opposite to the opening of the mold stator 10. At this time, the load-side rolling bearing 21 a is supported by the bearing support portion 11 formed at the axial end of the mold stator 10 on the side opposite to the opening.

  The rotor 20 has an anti-load-side rolling bearing 21b (an example of a rolling bearing) attached to the anti-load-side shaft 23b (right side in FIG. 1) (generally by press-fitting).

  Although details will be described later, an insulating component 26 is provided between the load side shaft 23a and the anti-load side shaft 23b of the shaft 23.

  FIG. 4 shows the first embodiment, and is a cross-sectional view of the bracket 30. The opening 10b of the mold stator 10 is closed, and the bracket 30 that supports the anti-load-side rolling bearing 21b is press-fitted into the mold stator 10. The bracket 30 supports the anti-load-side rolling bearing 21b with a bearing support portion 30a. The bracket 30 is press-fitted into the mold stator 10 by using a press-fit portion 30b having a substantially ring shape of the bracket 30 and a U-shaped cross section as an opening 10b in the inner peripheral portion 10a (mold resin portion) of the mold stator 10. This is done by press-fitting to the side. The outer diameter of the press-fit portion 30b of the bracket 30 is larger than the inner diameter of the inner peripheral portion 10a of the mold stator 10 by the press-fit allowance. The material of the bracket 30 is made of metal, for example, a galvanized steel plate. However, it is not limited to galvanized steel sheet.

  Since the present embodiment is characterized by the structure of the rotor 20, the mold stator 10 will be briefly described.

  A mold stator 10 shown in FIG. 2 includes a stator 40 and a mold resin 50 for molding. For the mold resin 50, for example, a thermosetting resin such as an unsaturated polyester resin is used. Since the stator 40 is attached with a substrate and the like which will be described later and has a weak structure, low pressure molding is desirable. Therefore, thermosetting resins such as unsaturated polyester resins are used.

FIG. 5 is a perspective view of the stator 40 showing the first embodiment. The stator 40 shown in FIG. 5 has the following configuration.
(1) An electromagnetic steel sheet having a thickness of about 0.1 to 0.7 mm is punched into a strip shape, and a strip-shaped stator core 41 is manufactured by laminating by caulking, welding, bonding, or the like. The strip-shaped stator core 41 includes a plurality of teeth 41a. The inner side to which a concentrated winding coil 42 described later is applied is a tooth 41a.
(2) The insulation part 43 is given to the teeth 41a. The insulating portion 43 is formed integrally with or separately from the stator core 41 using, for example, a thermoplastic resin such as PBT (polybutylene terephthalate).
(3) The concentrated coil 42 is wound around the tooth 41a provided with the insulating portion 43. A plurality of concentrated winding coils 42 are connected to form a three-phase single Y-connection winding. However, distributed winding may be used.
(4) Since it is a three-phase single Y connection, a terminal 44 (power supply to which power is supplied) is connected to the connection side of the insulating portion 43 to the coil 42 of each phase (U phase, V phase, W phase). Terminal 44a and neutral point terminal 44b) are assembled. There are three power terminals 44a and three neutral point terminals 44b.
(5) The board | substrate 45 is attached to the insulation part 43 (side in which the terminal 44 is assembled | attached) on the connection side. A substrate 45 on which a lead wire lead-out component 46 that leads out the lead wire 47 is assembled is assembled to the insulating portion 43 to form the stator 40. The chamfered rectangular column 48 of the insulating part 43 formed in the stator core 41 is inserted into a rectangular column insertion hole (not shown) provided in the substrate 45, thereby positioning in the rotational direction and the insulating unit 43. The position in the axial direction is determined by installing the substrate 45 on the substrate installation surface (not shown). Further, by thermally welding the prisms 48 protruding from the substrate 45, the substrate 45 and the insulating portion 43 are fixed, and the portion protruding from the substrate 45 of the terminal 44 provided in the stator 40 is electrically soldered. Are also joined. On the substrate 45, an IC 49a (drive element) for driving the electric motor 100 (for example, a brushless DC motor), a Hall IC 49b (position detection element, see FIG. 1) for detecting the position of the rotor 20, and the like are mounted. IC 49a, Hall IC 49b, etc. are defined as electronic components.

  Next, the configuration of the rotor 20 will be described. 6 to 11 show the first embodiment. FIG. 6 is a sectional view of the rotor 20, FIG. 7 is an exploded view of the rotor 20, and FIG. 8 is a sectional view of the rotor resin assembly 20-1. 9 is a side view of the rotor resin assembly 20-1 as viewed from the load side, FIG. 10 is a front view of the shaft 23, and FIG. 11 is an exploded view of the shaft 23.

  As shown in FIGS. 6 and 7, the rotor 20 includes a rotor resin assembly 20-1, a load side rolling bearing 21 a, and an anti-load side rolling bearing 21 b.

  The rotor resin assembly 20-1 includes a shaft 23 (see FIGS. 10 and 11), a ring-shaped rotor resin magnet 22 (an example of a rotor magnet), and a ring-shaped position detection resin magnet 25 (position detection). An example of a magnet for use), and a resin portion 24 for integrally molding them.

  The resin magnet 22 of the ring-shaped rotor, the shaft 23, and the position detection resin magnet 25 are integrated by a resin portion 24 injected by a vertical molding machine. At this time, the resin part 24 is formed on the outer periphery of the shaft 23, and a central cylinder part 24g (formed inside the rotor resin magnet 22), which will be described later, and the rotor resin magnet 22 are arranged in the central cylinder part 24g. And a plurality of axial ribs 24j (see FIG. 9) radially formed around the shaft 23 in the radial direction. A cavity 24k (see FIG. 9) penetrating in the axial direction is formed between the ribs 24j.

  A thermoplastic resin such as PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide) is used for the resin used for the resin portion 24. Those in which a glass filler is blended with these resins are also suitable.

  An anti-load side rolling bearing 21b is attached to the anti-load side shaft 23b (right side in FIG. 6) (generally by press fitting). A load-side rolling bearing 21a is attached to a load-side shaft 23a (left side in FIG. 6) to which a fan or the like is attached.

  Since the load side rolling bearing 21a and the anti-load side rolling bearing 21b are well-known rolling bearings, detailed description is omitted.

  The load-side rolling bearing 21a includes an inner ring 21a-1 that is press-fitted into the shaft 23, an outer ring 21a-2 that is supported by the bearing support portion 11 of the mold stator 10, and an inner ring 21a-1 and an outer ring 21a-2. And rolling elements 21a-3 that roll. A ball or a roller is used for the rolling element 21a-3.

  The anti-load-side rolling bearing 21b includes an inner ring 21b-1 that is press-fitted into the shaft 23, an outer ring 21b-2 that is supported by the bearing support portion 30a of the bracket 30, and an inner ring 21b-1 and an outer ring 21b-2. A rolling element 21b-3 that rolls. A ball or a roller is used for the rolling element 21b-3.

  In this embodiment, an insulating component 26 is interposed between the load-side shaft 23a and the anti-load-side shaft 23b of the metal (having conductivity) shaft 23, and the insulating component 26 is insulated to suppress the axial current. This is characterized in that the occurrence of electrolytic corrosion at the load-side rolling bearing 21a and the anti-load-side rolling bearing 21b is suppressed.

  Furthermore, the insulating component 26 provided between the load-side shaft 23a and the anti-load-side shaft 23b of the shaft 23 has a load-side shaft 23a and an anti-load-side shaft 23b at both ends (recesses 26a (FIG. 11)) of the insulating component 26. The end of each is inserted. Although not shown, some of the ends on the insulating component 26 side of the load side shaft 23a and the anti-load side shaft 23b are notched so as to be substantially D-shaped.

  In this state, the load side shaft 23a, the insulating component 26, and the anti-load side shaft 23b are not integrated. The shaft 23 (the load side shaft 23a, the insulating component 26, the anti-load side shaft 23b), the ring-shaped rotor resin magnet 22 and the ring-shaped position detection resin magnet 25 are integrated in the resin portion 24 to integrate the rotor resin. By molding 20-1, the insulating component 26 is also integrated.

  Thus, since the insulating component 26 assembled between the load side shaft 23a and the anti-load side shaft 23b of the shaft 23 is integrated and fixed by the resin portion 24, the fixing of the insulating component 26 becomes extremely simple. In addition, the possibility of the insulation component 26 being detached from the shaft 23 is reduced.

  The present embodiment also includes a rotor 20 that does not have the ring-shaped position detecting resin magnet 25.

  FIG. 12 is an enlarged view of a portion B in FIG. As shown in FIG. 12, the resin portion 24 has a bearing abutment surface 24d for positioning in the axial direction when the anti-load-side rolling bearing 21b is inserted into the anti-load-side shaft 23b. It is formed at the opposite end of the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery with the component 26 as the center.

  And the step part 24e is provided in the center cylinder part 24g of the resin part 24 formed in the outer periphery centering on the insulation component 26 assembled | attached to the shaft 23 at the bearing contact surface 24d side. The diameter of the stepped portion 24e is smaller by a predetermined amount than the diameter of the other portion of the central cylindrical portion 24g.

  It is essential that the diameter of the stepped portion 24e is smaller than the inner diameter of the outer ring 21b-2 of the anti-load side rolling bearing 21b. FIG. 13 is an enlarged view of part A of FIG. In the rotor 20 shown in FIG. 13, the diameter of the stepped portion 24e is substantially the same as or slightly smaller than the outer diameter of the inner ring 21b-1 of the anti-load side rolling bearing 21b.

  Generally, a rolling bearing is provided with a cover between an outer ring and an inner ring so that grease does not leak out from the inside of the rolling bearing or dust does not enter from the outside. This cover is located inside the both end faces of the rolling bearing.

  Therefore, even if the diameter of the stepped portion 24e is made larger than the outer diameter of the inner ring 21b-1 of the anti-load side rolling bearing 21b, the portion larger than the outer diameter of the inner ring 21b-1 becomes the anti-load side rolling bearing 21b. Do not touch. Accordingly, the diameter of the stepped portion 24e is practically the same as or slightly smaller than the outer diameter of the inner ring 21b-1 of the anti-load side rolling bearing 21b.

  By providing the stepped portion 24e, when the shaft 23 (the load side shaft 23a, the insulating component 26, the anti-load side shaft 23b), the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrally formed with resin, the resin When the bearing contact surface 24d of the central cylindrical part 24g of the part 24 is formed by erection, it is formed by the erection up to the step part 24e. For this reason, the mating surface of the mold becomes the anti-load side end surface 24h (see FIG. 12) of the central cylindrical portion 24g. Therefore, even if burrs occur on the mating surface of the mold, the anti-load side rolling bearing 21b The burr is not in contact with the anti-load-side rolling bearing 21b because it is separated from the anti-load-side end surface 24h that is the mating surface by the stepped portion 24e. Therefore, there is little possibility of adversely affecting the anti-load side rolling bearing 21b.

  Further, when the rotor 20 receives a thermal shock, the central cylindrical portion 24g of the resin portion 24 may break. Even in such a case, the step portion 24e is provided in the central cylindrical portion 24g, the radial dimension of the step portion 24e is constant, and the radial direction of the central cylindrical portion 24g between the step portions (the load side and the anti-load side) at both ends is provided. This can be dealt with by increasing the thickness.

  Since the diameter of the stepped portion 24e is smaller than the inner diameters of the outer rings 21a-2 and 21b-2 of the load side rolling bearing 21a and the anti-load side rolling bearing 21b, the diameter of the central cylindrical portion 24g between the stepped portions 24e is reduced. It is also possible to make it larger than the inner diameter of the outer rings 21a-2 and 21b-2.

  14 to 17 are diagrams showing the first embodiment, FIG. 14 is a diagram showing the insulating component 26 ((a) is a side view, (b) is a front view), and FIG. 15 is an enlarged view of a portion C in FIG. FIG. 16 is an enlarged side view of the convex portion 26b of the insulating component 26, and FIG. 17 is an enlarged view of the D portion of FIG.

  As shown in FIG. 14, the insulating component 26 is provided with a concave portion 26a for assembling a shaft that is substantially cylindrical and that is secured coaxially at both ends. By making the diameter of the recess the same as the outer diameter of the shaft, it is possible to suppress the processing cost of the shaft. Although not shown, the recess 26a has a substantially D shape when viewed from the side, and a part of the circular shape protrudes inward. When a notch corresponding to the D-shaped concave portion provided at the end of the shaft on the side where the insulating part is assembled is fitted, and when rotating integrally with the load side shaft 23a and the anti-load side shaft 23b, the rotation between the insulating part and the shaft is stopped. As a result, the quality of the rotor of the electric motor can be improved. In the case where the concave portion is provided with a protruding portion, the protruding portion is located on the side opposite to the gate of the insulating component 26, so that the weld strength of the insulating component can be improved. The insulating component 26 includes seven convex portions 26b formed at equal intervals in the circumferential direction on the outer periphery of a substantially central portion in the axial direction. In short, the shape of the convex portion 26b is “substantially a quadrangular pyramid”. One of the five corners of the quadrangular pyramid is the apex 26b-1 (FIGS. 15 to 17) at the substantially central portion in the axial direction, and the two corner portions are the outer circumferential circle of the insulating component 26 at the substantially central portion in the axial direction. It is located at intersecting points a and b (FIG. 16), and the remaining two corners are located at intersecting points c and d at a predetermined distance in the axial direction from the substantially central portion in the axial direction (FIG. 17).

The convex part 26b is the structure shown below.
(1) First of all, the shape at the substantially central portion in the axial direction is defined as a vertex 26b-1 at a position away from the outer periphery by a predetermined distance, and a radius passing through the vertex 26b-1 (the outer periphery of the vertex 26b-1 and the insulating component 26). (A line connecting the centers of the circles) at substantially equal triangles (α) on both sides at intersections a and b with the outer circumference circle of the insulating component 26 (see FIG. 16).
(2) Secondly, the shapes on both sides in the axial direction from the substantially central portion in the axial direction intersect at the intersections c and d with the outer peripheral surface of the insulating component 26 in the axial direction at a predetermined angle (β) from the vertex 26b-1. It has a substantially triangular shape (see FIG. 17).
(3) As shown in FIG. 14A, the plurality of convex portions 26b are formed at substantially equal intervals in the circumferential direction. In the example of FIG. 14A, seven convex portions 26b are formed at intervals of approximately 45 °.

  The insulating component 26 has a gate cutting portion 26c of a resin injection port having a predetermined height and extending in the axial direction with a predetermined width at the time of resin molding in the vicinity of a substantially central portion in the axial direction, as shown in FIG. As described above, each of the two convex portions 26b is positioned at a substantially central portion of the two convex portions 26b at an interval of approximately 45 °.

  The convex portion 26b of the insulating component 26 shown in FIG. 14 is an example, and the shape thereof is not limited to “substantially a quadrangular pyramid”. The convex part 26b has a vertex in the vicinity of the substantially central part in the axial direction of the insulating component 26, and any configuration may be used as long as the convex part 26b faces the outer peripheral surface of the convex part 26b for a while in the circumferential direction or the axial direction. And the outer peripheral surface of the convex part 26b may not be a plane, but a curved surface may be sufficient as it.

  When the insulating part 26 is integrated by the resin part 24, the central cylindrical part 24g covers and integrates the convex part 26b in the vicinity of the substantially central part in the axial direction of the insulating part 26, so that the axial direction and the circumferential direction of the insulating part 26 are integrated. The movement of is suppressed.

  When the convex portion 26b of the insulating component 26 is embedded in the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the shaft 23, the convex portion 26b is predetermined (substantially central in the axial direction) with respect to the outer peripheral surface of the insulating component 26. The outer peripheral surface is reached at an equal angle (α) from the apex 26b-1 in the vicinity of the portion (see FIG. 16). Thereby, since the space between the convex portions 26b becomes a part of the central cylindrical portion 24g of the resin portion 24, the thickness of the central cylindrical portion 24g of the resin portion 24 in the vicinity of the insulating component 26 can be secured.

  Further, by causing the convex portion 26b of the insulating component 26 to reach the outer peripheral surface of the insulating component 26 at a predetermined angle (β) with respect to the axial direction from the apex 26b-1 (see FIG. 17), the resin portion 24 The thickness in the vicinity of the end surface in the axial direction of the central cylindrical portion 24g can be secured.

  By forming the convex portion 26b that prevents the insulation component 26 integrally formed with the resin portion 24 from rotating and coming off as described above, the central cylindrical portion 24g of the resin portion 24 is formed in the vicinity of the convex portion 26b. . Therefore, the thickness of the central cylinder part 24g of the resin part 24 can be ensured. This makes it possible to reduce costs and ensure quality.

  The electric motor 100 (including the rotor 20) is required to have thermal shock resistance. The resin portion 24 made of a thermoplastic resin such as PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide) and the shaft 23 made of iron have different linear expansion coefficients. There is a possibility that the central tube portion 24g of the resin portion 24 may break. Therefore, the central cylindrical part 24g of the resin part 24 needs to have a predetermined thickness. By forming the convex part 26b that prevents the insulation component 26 integrally formed with the resin part 24 from rotating and coming off as described above, the thickness of the central cylindrical part 24g of the resin part 24 near the convex part 26b is increased. It can be ensured without increasing the outer diameter of the central cylindrical portion 24g.

As the material of the insulating component 26, it is preferable to use a resin material having substantially the same linear expansion coefficient as that of iron (the shaft 23). As such a resin material, for example, a BMC resin of a thermosetting resin can be given. BMC (bulk molding compound) resin is a block clay-like thermosetting resin in which various additives are added to an unsaturated polyester resin. BMC resin has the following characteristics.
(1) Good productivity due to shorter curing time than epoxy resin;
(2) Good balance between material cost and properties;
(3) Possible to mold at low pressure;
(4) High dimensional stability;
(5) High surface hardness and hardly scratched;
(6) Lighter than metal, excellent in moldability of complex shapes, and excellent in vibration absorption.

  In the rotor of the electric motor, stress is generated when the thermal history of rising and falling heat is received and the linear expansion coefficients of iron and resin are different. For this reason, the resin undergoes a creep phenomenon (a phenomenon in which the deformation of the material increases with time under a constant load), and the portion where the load side shaft and the anti-load side shaft are inserted is the initial dimension. May not be maintained. In this case, there is a possibility that the coaxiality between the shafts on both sides and the resin magnet of the rotor may be lowered or the shaft may be slipped, and there is a concern that the quality may be lowered. On the other hand, quality can be improved by using a thermosetting resin having high creep resistance and using a BMC resin having a linear expansion coefficient close to that of iron.

  The insulation part thickness d (FIG. 14B) in the axial direction of the insulation component 26 is, for example, 1.0 to 4.0 mm. However, it is not limited to this range.

  18A and 18B are views showing the resin magnet 22 of the rotor, FIG. 18A is a left side view, FIG. 18B is a cross-sectional view taken along line AA of FIG. 18A, and FIG. is there. A configuration of the resin magnet 22 of the ring-shaped rotor will be described with reference to FIG. The rotor resin magnet 22 has an axial end of the inner diameter (on the right side in FIG. 18B) to ensure the coaxiality of the shaft 23 and the rotor resin magnet 22 during mold clamping during resin molding. The notch 22a is formed. In the example of FIG. 18, the notches 22a are formed at eight locations at substantially equal intervals in the circumferential direction (FIG. 18 (c)).

  In addition, on the resin magnet 22 of the rotor, pedestals 22b for mounting the position detection resin magnet 25 are formed at substantially equal intervals in the circumferential direction on the end surface of the other axial end portion (left side in FIG. 18B). ing.

  The pedestal 22b is formed from the vicinity of the inner diameter of the resin magnet 22 of the rotor toward the outer diameter, and the positioning projection 22c is radially directed from the tip of the pedestal 22b toward the outer periphery of the resin magnet 22 of the rotor. It extends to. The positioning protrusions 22c are used for positioning the rotor resin magnet 22 in the circumferential direction (rotation direction) when the rotor magnet, the position detection magnet, and the shaft are integrally formed by the resin portion 24.

  FIG. 19 is a diagram illustrating the first embodiment, and is a diagram illustrating the position detecting resin magnet 25 ((a) is a left side view, (b) is a front view, and (c) is an enlarged view of a portion F in (b)). It is. The structure of the ring-shaped position detection resin magnet 25 will be described with reference to FIG. FIG. 19A is a left side view of the position detection resin magnet 25, FIG. 19B is a front view of the position detection resin magnet 25, and FIG. 19C is an enlarged view of a portion F of FIG.

  The position detecting resin magnet 25 includes steps 25b at both axial end portions on the inner diameter side. The step 25b is necessary to prevent the position detecting resin magnet 25 from coming off in the axial direction by filling the step 25b on the axial end portion side of the rotor 20 with a part of the resin portion 24.

  In FIG. 19, the step provided with the step 25 b at both ends is shown, but the step 25 b may be provided at either one end, and it should be positioned on the axial end portion side of the rotor 20. However, when both ends are provided with a step 25b, the position detection resin magnet 25 is set without worrying about the front and back when the resin magnet 24 for position detection is set on the mold (lower mold) when the resin portion 24 of the rotor 20 is integrally formed. Excellent workability because it can.

  Further, the position detecting resin magnet 25 includes eight ribs 25a (substantially triangular in cross section) that are circumferentially detented when embedded in the resin portion 24 in the step 25b at substantially equal intervals in the circumferential direction. However, the number, shape, and arrangement interval of the ribs 25a may be arbitrary.

  As shown in FIG. 8, in the resin portion 24, the inner diameter pressing portion 24a of the mold for holding the inner diameter of the position detection resin magnet 25 and the position detection resin magnet 25 are set in the mold (lower mold). A taper part 24b for facilitating and a resin injection part 24c at the time of resin molding are formed after resin molding.

  The rotor resin magnet 22 is formed by mixing a thermoplastic material with a magnetic material. As shown in FIG. 18, the inner diameter is provided with a notch 22a in a tapered shape from one end surface in the axial direction. A pedestal 22b on which the position detecting resin magnet 25 is placed is provided on the other axial end surface opposite to one axial end surface.

  The pedestal 22b of the rotor resin magnet 22 formed integrally with the shaft 23 enables the position detection resin magnet 25 to be separated from the end surface of the rotor resin magnet 22, and the thickness of the position detection resin magnet 25 is increased. Can be disposed at an arbitrary position, and the cost can be reduced by filling a thermoplastic resin cheaper than the resin magnet 22 of the rotor.

  As shown in FIG. 19, the position detecting resin magnet 25 has steps 25b on both sides in the thickness direction, and ribs 25a that prevent rotation when embedded in the resin, on the steps 25b on both sides. Further, the coaxiality between the inner diameter of the position detecting resin magnet 25 and the outer diameter of the position detecting resin magnet 25 is made with high accuracy.

  When molded integrally with the shaft 23, the outer periphery of the position detection resin magnet 25 is filled with a taper-shaped resin (resin portion 24). Correspondingly, the resin to be filled is blocked by the axial end face (outer side) on one side of the position detection resin magnet 25 and the axial end faces of the rotor resin magnet 22, so that the outer diameter of the rotor resin magnet 22 is variable. It is possible to suppress the occurrence of the problem, and the quality is improved.

  Further, by arranging the gate port at the time of integral molding with the shaft 23 further inside than the inner diameter of the resin magnet 22 of the rotor and arranging the resin injection portion 24c in a convex shape, the concentration of pressure is alleviated, and the resin Can be easily filled, and the convex portion of the resin injection portion 24c can be used for positioning.

  Next, the effect of insulating the load side shaft 23a and the anti-load side shaft 23b of the shaft 23 by the insulating component 26 will be described.

  First, for comparison, an electric motor 400 that uses a rotor core as a rotor and does not use an insulating component 26 will be described.

  20 and 21 are diagrams for comparison. FIG. 20 is a cross-sectional view of an electric motor 400 using a rotor core (insulating parts are not used) (and also shows a current path of an axial current), and FIG. It is a figure which shows the measurement result of an axial current.

  The electric motor 400 that uses the rotor core for the rotor and does not use the insulating component 26 uses the rotor core for the rotor and does not use the insulating component 26, so that the shaft current easily flows. As shown in FIG. 20, on the board side, axial current flows in the path of shaft → rotor core → stator core → coil → board → load-side rolling bearing → shaft.

  Further, as shown in FIG. 20, on the side opposite to the board, axial current flows in the path of shaft → rotor core → stator core → coil → bracket → counter load bearing on the opposite side → shaft. Since the axial current is alternating current, when the polarities are opposite, the reverse path is obtained.

  However, a part of the axis current path shown in FIG. 20 is shown. There are actually multiple paths. Therefore, in the axial current measurement results shown below, the axial current values are different between the substrate side and the non-substrate side.

And the measurement result of the axial current of the electric motor 400 was a result as shown in FIG.
(1) On the substrate side, the maximum value (single amplitude) of the axial current is 5.0 mA and the minimum value (single amplitude) is −5.0 mA;
(2) On the side opposite to the substrate, the maximum value (single amplitude) of the axial current is 59.17 mA, and the minimum value (single amplitude) is −60.0 mA.
The measurement result shown in FIG. 21 is an example, and the value of the axial current may be large on the substrate side, and the value of the axial current may be small on the non-substrate side.

  Next, for comparison, an electric motor 500 in which the rotor is molded from resin without using the rotor core as the rotor and the insulating component 26 is not used will be described.

  22 and 23 are diagrams for comparison, and FIG. 22 is a cross-sectional view of an electric motor 500 (not using an insulating component) that molds a rotor with resin (also shows a current path of an axial current). FIG. 23 is a diagram showing the measurement result of the shaft current of the electric motor 500.

  The electric motor 500 in which the rotor is formed of resin without using a rotor core as the rotor and the insulating component 26 is not used has a reduced shaft current compared to the electric motor 400. The path of the shaft current is shaft → anti-load side rolling bearing → bracket → coil → stator core → coil → substrate → load side rolling bearing → shaft. Since the axial current is alternating current, when the polarities are opposite, the reverse path is obtained.

And the measurement result of the axial current of the electric motor 500 was a result as shown in FIG.
(1) On the substrate side, the maximum value (single amplitude) of the axial current is 9.2 mA and the minimum value (single amplitude) is −16.7 mA;
(2) On the side opposite to the substrate, the maximum value (single amplitude) of the axial current is 27.5 mA, and the minimum value (single amplitude) is −26.7 mA.
Thus, compared to the electric motor 400, the axial current is reduced to about 50%, particularly on the non-substrate side. This is the effect of molding the rotor with resin without using a rotor core for the rotor.

  The shaft current path and the measurement result of the shaft current of the electric motor 100 according to the present embodiment (which insulates between the load side shaft 23a and the anti-load side shaft 23b of the shaft 23 by the insulating component 26) will be described.

  24 and 25 are diagrams showing the first embodiment, FIG. 24 is a cross-sectional view of the electric motor 100 (showing a current path of the axial current), and FIG. 25 is a diagram showing a measurement result of the axial current of the electric motor 100.

  The shaft current path of the electric motor 100 in the present embodiment is as follows: anti-load side shaft → anti-load side rolling bearing → bracket → coil → stator core → coil → board → load side rolling bearing → load side shaft → insulating component → anti It becomes the load side shaft. Since the axial current is alternating current, when the polarities are opposite, the reverse path is obtained.

  In the electric motor 100 of the present embodiment, the load-side shaft 23a and the anti-load-side shaft 23b of the shaft 23 are insulated by the insulating component 26, so that the shaft current is reduced as compared with the electric motor 500 of the comparative example.

The measurement result of the shaft current of the electric motor 100 of the present embodiment was as shown in FIG.
(1) On the substrate side, the maximum value (single amplitude) of the axial current is 7.5 mA, and the minimum value (single amplitude) is −10.8 mA;
(2) On the side opposite to the substrate, the maximum value (single amplitude) of the axial current is 17.5 mA, and the minimum value (single amplitude) is -17.5 mA.
Thus, compared to the electric motor 500, the axial current is reduced to about 60%, particularly on the non-substrate side. This is an effect in which the load-side shaft 23a and the anti-load-side shaft 23b of the shaft 23 are insulated by the insulating component 26.

  FIG. 26 is a diagram showing the first embodiment, and is a cross-sectional view of a rotor 20a of a first modification. A difference from the rotor 20 shown in FIG. 6 is that center holes 23g are formed at the ends of the load side shaft 23-1a and the anti-load side shaft 23-1b.

  The rotor 20a of Modification 1 includes a rotor resin assembly 20-1a, a load side rolling bearing 21a, and an anti-load side rolling bearing 21b. The rotor resin assembly 20-1a is different from the rotor resin assembly 20-1 of the rotor 20.

  The mold (upper mold) is provided with a protrusion that fits in the center hole 23g of the shaft 23-1 and is coaxial with the upper mold and the lower mold shaft insertion portion. When the shaft 23-1, the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24, the protrusion of the mold (upper mold) becomes the center hole 23g of the shaft 23-1. The degree of coaxiality between the rotor resin magnet 22 and the shaft 23-1 can be improved.

  27 to 29 are diagrams showing the first embodiment. FIG. 27 is a cross-sectional view of the rotor 20b of the second modification. FIG. 28 is an exploded view of the shaft 23-2 of the rotor 20b of the second modification. These are sectional drawings of the insulation component 26-1 of the rotor 20b of the modification 2. FIG.

  The rotor 20b of Modification 2 is different from the rotor 20 shown in FIG. 6 in that the shaft insertion recess 26-1a provided on both end faces of the insulating component 26-1 decreases in diameter from the opening toward the bottom. The end part on the insulating component 26-1 side of the load side shaft 23-2a and the anti-load side shaft 23-2b is also a taper shape corresponding to the taper of the concave part 26-1a. (See FIG. 28).

  The rotor 20b of Modification 2 includes a rotor resin assembly 20-1b, a load side rolling bearing 21a, and an anti-load side rolling bearing 21b. The rotor resin assembly 20-1b is different from the rotor resin assembly 20-1 of the rotor 20.

  As shown in FIG. 29, in the insulating component 26-1, a shaft insertion recess 26-1a provided on both end faces has a tapered shape whose diameter decreases from the opening toward the bottom. The convex portion 26-1b formed at the substantially central portion in the axial direction of the insulating component 26-1 is the same as the convex portion 26b of the insulating component 26. Further, the gate cutting part 26-1c of the resin injection port is the same as the gate cutting part 26c of the insulating component 26.

  The shaft 23-2 (load side shaft 23-2a, anti-load side shaft 23-2b, insulating component 26-1), the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24. In doing so, the load-side shaft 23-2a and the anti-load-side shaft 23-2b are fitted into the end of the insulation component 26-1 side in the tapered recess 26-1a of the insulation component 26-1, so that the load side It is possible to improve the coaxiality of the shaft 23-2a and the anti-load side shaft 23-2b.

  30 to 32 are diagrams showing the first embodiment. FIG. 30 is a cross-sectional view of the rotor 20c of the third modification. FIG. 31 is an exploded view of the shaft 23-3 of the rotor 20c of the third modification. These are sectional drawings of the insulation component 26-2 of the rotor 20c of the modification 3. FIG.

  The rotor 20c of Modification 3 is different from the rotor 20 shown in FIG. 6 in that the insulating component 26-2, the load side shaft 23-3a and the anti-load side shaft 23-3b are assembled with screws. .

  The rotor 20c of Modification 3 includes a rotor resin assembly 20-1c, a load side rolling bearing 21a, and an anti-load side rolling bearing 21b. The rotor resin assembly 20-1c is different from the rotor resin assembly 20-1 of the rotor 20.

  A threaded portion 23-3c is cut at the end of the load side shaft 23-3a on the insulating component 26-2 side. Further, a threaded portion 23-3d is cut at the end of the anti-load side shaft 23b-3 on the insulating component 26-2 side (see FIG. 31).

  As for the insulating component 26-2, the screw part 26-2d is cut in the inner periphery of each recessed part 26-2a. The convex portion 26-2b and the gate cutting portion 26-2c of the resin injection port are the same as the convex portion 26b and the gate cutting portion 26c (see FIG. 32).

  The shaft 23-3 (load-side shaft 23-3a, anti-load-side shaft 23b-3, insulating component 26-2), the rotor resin magnet 22 and the position detection resin magnet 25 are integrated (molded) by the resin portion 24. When the insulating component 26-2, the load side shaft 23-3a and the anti-load side shaft 23b-3 are assembled with screws, the load side shaft 23-3a and the anti-load side shaft 23b-3 are coaxial. It is possible to improve the degree.

  33 to 35 are diagrams showing the first embodiment. FIG. 33 is a cross-sectional view of the rotor 20d according to the fourth modification. FIG. 34 is an exploded view of the shaft 23-4 of the rotor 20d according to the fourth modification. These are sectional drawings of insulation component 26-3 of rotor 20d of modification 4.

  The rotor 20d of Modification 4 is different from the rotor 20 shown in FIG. 6 in that the portion where the insulating component 26-3 of the load side shaft 23-4a and the anti-load side shaft 23-4b is assembled is the insulating component 26. -3, and the diameter (center part) of the load side shaft 23-4a and the anti-load side shaft 23-4b is substantially the same as the diameter of the insulating component 26-3.

  The rotor 20d of Modification 4 includes a rotor resin assembly 20-1d, a load side rolling bearing 21a, and an anti-load side rolling bearing 21b. The rotor resin assembly 20-1d is different from the rotor resin assembly 20-1 of the rotor 20.

  An insulating component fitting portion 23-4c thinner than the central portion is formed at the end of the load side shaft 23-4a on the insulating component 26-3 side. Further, an insulating component fitting portion 23-4d that is thinner than the center portion is formed at the end of the anti-load side shaft 23-4b on the insulating component 26-3 side (see FIG. 34).

  In the insulating component 26-3, each concave portion 26-3a corresponds to the insulating component fitting portion 23-4c of the load side shaft 23-4a or the insulating component fitting portion 23-4d of the anti-load side shaft 23-4b. Yes. The recess 26-3a of the insulating component 26-3 has a smaller inner diameter than the recess 26a of the insulating component 26. Further, the convex portion 26-3b and the gate cutting portion 26-3c of the resin injection port are the same as the convex portion 26b and the gate cutting portion 26c (see FIG. 35).

  The shaft 23-4 (the load side shaft 23-4a, the anti-load side shaft 23-4b, the insulating component 26-3), the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24. In this case, it is possible to improve the quality of the rotor 20d by securing the thickness of the resin portion 24 formed around the insulating component 26-3. In addition, the end of the insulating component 26-3 is brought into contact with the ends of the load side shaft 23-4a and the anti-load side shaft 23-4b to perform axial positioning, thereby improving the quality of the rotor 20d. Is possible.

  36 to 38 are diagrams showing the first embodiment. FIG. 36 is a cross-sectional view of the rotor 20e of the fifth modification. FIG. 37 is an exploded view of the shaft 23-5 of the rotor 20e of the fifth modification. These are sectional drawings of insulation component 26-4 of rotor 20e of modification 5.

  The rotor 20e of the modified example 5 differs from the rotor shown in FIG. 6 in that the insulating component 26-4 is substantially cylindrical and the shaft assembly portion is a through hole 26-4a.

  The rotor 20e of Modification 5 includes a rotor resin assembly 20-1e, a load side rolling bearing 21a, and an anti-load side rolling bearing 21b. The rotor resin assembly 20-1e is different from the rotor resin assembly 20-1 of the rotor 20.

  The shaft 23-5 includes a load side shaft 23-5a, an anti-load side shaft 23-5b, and an insulating component 26-4. The shaft 23-5 of the modification 5 is different from the shaft 23-4 of the modification 4 in the insulating component 26-4.

  An insulating component fitting portion 23-5c thinner than the center portion is formed at the end of the load side shaft 23-5a on the insulating component 26-4 side. Further, an insulating component fitting portion 23-5d that is thinner than the center portion is formed at the end of the anti-load side shaft 23-5b on the insulating component 26-5 side (see FIG. 37).

  The insulating component 26-4 has a substantially cylindrical shape, and the through hole 26-4a has an insulating component fitting portion 23-5c of the load side shaft 23-5a or an insulating component fitting portion 23-5d of the anti-load side shaft 23-5b. It corresponds to. The convex portion 26-4b and the gate cutting portion 26-4c of the resin injection port are the same as the convex portion 26b and the gate cutting portion 26c (see FIG. 38).

  The shaft 23-5 (load-side shaft 23-5a, anti-load-side shaft 23-5b, insulating component 26-4), the rotor resin magnet 22 and the position detection resin magnet 25 are integrated (molded) by the resin portion 24. In this case, the through hole 26-4a of the insulating component 26-4 is formed on one of the upper and lower molds for forming the insulating component 26-4, and the insulating component of the load side shaft 23-5a is formed in the through hole 26-4a. The coaxiality of the load side shaft 23-5a and the anti-load side shaft 23-5b is improved by assembling the fitting portion 23-5c and the insulating part fitting portion 23-5d of the anti-load side shaft 23-5b. It is possible to do.

  39 to 41 are diagrams showing the first embodiment. FIG. 39 is a cross-sectional view of the rotor 20f according to the sixth modification. FIG. 40 is an exploded view of the shaft 23-6 of the rotor 20f according to the sixth modification. These are sectional drawings of insulation component 26-5 of rotor 20f of modification 6.

  The rotor 20f of the modified example 6 is different from the rotor shown in FIG. 6 in that the insulating component 26-5 is slightly smaller than the outer diameters of the load side shaft 23-6a and the anti-load side shaft 23-6b. It is cylindrical and is provided with a flange portion 26-5e (FIG. 41) that protrudes to the same outer diameter as the outer diameter of the load side shaft 23-6a and the opposite load side shaft 23-6b.

  The rotor 20f of Modification 6 includes a rotor resin assembly 20-1f, a load side rolling bearing 21a, and an anti-load side rolling bearing 21b. The rotor resin assembly 20-1f is different from the rotor resin assembly 20-1 of the rotor 20.

  The shaft 23-6 includes a load side shaft 23-6a, an anti-load side shaft 23-6b, and an insulating component 26-5.

  An insulating component fitting recess 23-6c is formed at the end of the load side shaft 23-5a on the insulating component 26-5 side. Further, an insulating component fitting recess 23-6d is formed at the end of the non-load side shaft 23-6b on the insulating component 26-5 side (see FIG. 40).

  The insulating component 26-5 has a substantially cylindrical shape that is slightly smaller than the outer diameter of the load side shaft 23-6a and the anti-load side shaft 23-6b, and the load side shaft 23-6a and the anti-load side shaft 23- It has a flange portion 26-5e that protrudes to the same outer diameter as that of 6b. Shaft portions 26-5d are formed on both sides of the flange portion 26-5e. The shaft portion 26-5d corresponds to the insulating component fitting recess 23-6c of the load side shaft 23-6a and the insulating component fitting recess 23-6d of the anti-load side shaft 23-6b. Further, the convex part 26-5b and the gate cutting part 26-5c of the resin injection port are the same as the convex part 26b and the gate cutting part 26c (see FIG. 41).

  The shaft 23-6 (load-side shaft 23-6a, anti-load-side shaft 23-6b, insulating component 26-5), the rotor resin magnet 22 and the position detection resin magnet 25 are integrated (molded) with the resin portion 24. In this case, the thickness of the resin portion 24 formed around the insulating component 26-5 is substantially uniform, and the strength of the resin portion 24 is ensured while preventing defects such as sinks in the resin portion 24, and the rotor 20f. It is possible to improve quality. Further, the ends of the load side shaft 23-6a and the anti-load side shaft 23-6b are brought into contact with the flange portion 26-5e of the insulating component 26-5 to perform axial positioning, thereby improving the quality of the rotor 20f. It is possible to plan.

  In addition, although the electric motor 100 shown in FIG. 1 showed what the mold stator 10 side becomes a load side and the bracket 30 side becomes an anti-load side, the reverse may be sufficient.

  The rotor 20 and the rotors 20a to 20f shown in FIGS. 6, 26, 27, 30, 33, 36, and 39 are formed by mixing a permanent magnet with a thermoplastic material and a magnetic material. However, other permanent magnets (rare earth magnets (neodymium, samarium iron nitrogen), ferrite sintered, etc.) may be used.

  Similarly, other permanent magnets (rare earth magnets (neodymium, samarium iron nitrogen), sintered ferrite, etc.) may be used for the position detecting resin magnet 25.

  As described above, when an electric motor is operated using an inverter, the carrier frequency of the inverter is set high for the purpose of reducing the noise of the electric motor generated due to the switching of the transistor in the power circuit. Yes. As the carrier frequency is set higher, the shaft voltage generated on the shaft of the motor based on the high frequency induction increases, and the potential difference existing between the inner ring and the outer ring of the rolling bearing supporting the shaft increases. This makes it easier for current to flow through the rolling bearing. The current flowing through the rolling bearings causes corrosion called electro-corrosion on the rolling surfaces of both the inner and outer ring raceways and the rolling elements (balls and rollers rolling between the inner and outer rings), thereby deteriorating the durability of the rolling bearings. .

  Therefore, the rotor 20 and the rotors 20a to 20f of the present embodiment are particularly effective for reducing the shaft current when the electric motor 100 is operated using an inverter.

  FIG. 42 is a configuration diagram of a drive circuit 200 that drives the electric motor 100. As shown in FIG. 42, the inverter type drive circuit 200 includes a position detection circuit 110, a waveform generation circuit 120, a pre-driver circuit 130, and a power circuit 140.

  The position detection circuit 110 detects the magnetic pole of the position detection resin magnet 25 of the rotor 20 using the Hall IC 49b.

  The waveform generation circuit 120 generates a PWM (Pulse Width Modulation) signal for driving the inverter based on a speed command signal for instructing the rotation speed of the rotor 20 and a position detection signal from the position detection circuit 110, and a pre-driver Output to the circuit 130.

  The pre-driver circuit 130 outputs a transistor drive signal that drives the transistors 141 (six) of the power circuit 140.

  The power circuit 140 includes a DC power supply input unit and an inverter output unit, and includes an arm in which a transistor 141 and a diode 142 are connected in parallel and further connected in series.

  Since the electric motor 100 has three phases, a three-arm inverter output unit is connected to each coil 42. Connected to the DC power supply input section is a 140V or 340V DC power supply +, − obtained by rectifying 240V from AC 100V of commercial power.

  When the speed command signal is input to the drive circuit 200, the waveform generation circuit 120 sets the energization timing to each of the three-phase coils 42 according to the position detection signal and generates a PWM signal according to the input of the speed command signal. The pre-driver circuit 130 that outputs the PWM signal drives the transistor 141 in the power circuit 140.

  The inverter output unit drives the transistor 141 to apply a voltage to the coil 42, a current flows through the coil 42, torque is generated, and the rotor 20 rotates. It becomes the rotational speed of the electric motor 100 according to a speed command signal. The motor 100 is also stopped by a speed command signal.

FIG. 43 shows a manufacturing process of the rotor 20.
(1) Forming and demagnetizing the resin magnet 25 for position detection and the resin magnet 22 of the rotor. The load side shaft 23a and the anti-load side shaft 23b are processed, and the insulating component 26 is formed (step 1).
(2) The position detection resin magnet 25 is set in the lower mold with the end portion having the step 25b facing downward, and the inner diameter pressing portion provided in the lower mold holds the inner diameter of the position detection resin magnet 25 (step 2). ).
(3) The positioning projection 22c of the resin magnet 22 of the rotor is fitted into the positioning projection insertion portion provided in the lower mold and set in the lower mold (step 3).
(4) The shaft 23 assembled with the insulating component 26 is set in the lower mold, and the mold is clamped so that the notch 22a of the resin magnet 22 of the rotor is pressed by the notch holding portion of the upper mold (step 4). .
(5) Resin (resin portion 24) is molded (step 5). When the resin magnet 22 of the rotor, the resin magnet 25 for position detection, and the shaft 23 are integrally formed by the resin portion 24, the insulating component 26 is interposed between the load side shaft 23a and the anti-load side shaft 23b. Is integrally molded.
(6) The position detecting resin magnet 25 and the rotor resin magnet 22 are magnetized (step 6).
(7) The load-side rolling bearing 21a and the anti-load-side rolling bearing 21b are assembled to the shaft 23 (step 7).

  According to the manufacturing process described above, the shaft 23 (load-side shaft 23a, anti-load-side shaft 23b, insulating component 26), the rotor resin magnet 22 and the position detection resin magnet 25 are made of resin (resin portion 24). When integrating, all parts are set in a mold and resin-molded, so that the cost of the rotor 20 can be reduced by reducing the work process.

  Further, the pedestal 22b of the rotor resin magnet 22 enables the position detection resin magnet 25 to be separated from the end surface of the rotor resin magnet 22, and the thickness of the position detection resin magnet 25 is minimized and arbitrary. The cost can be reduced by filling a thermoplastic resin that is cheaper than the resin magnet 22 of the rotor.

  Further, since the position detecting resin magnet 25 is symmetrical in the thickness direction, it can be set in the mold without matching the orientation.

  In addition, since the portion through which the outer diameter passes when setting the lower mold position detection resin magnet 25 is tapered (tapered portion 24b of the resin portion 24), the lower die position detecting resin magnet 25 is set without being caught by the lower die. Therefore, the cost can be reduced with the improvement of productivity by simplifying the work process.

  Further, when the position detecting resin magnet 25 is set in the lower mold, the inner diameter is held by the inner diameter pressing portion provided in the lower mold, thereby ensuring the coaxiality between the shaft 23 and the resin magnet 22 of the rotor. .

  Further, the notch holding portion provided in the upper die presses the notch 22a provided in the inner diameter of the resin magnet 22 of the rotor, so that the coaxiality between the shaft 23 and the resin magnet 22 of the rotor is ensured.

  As described above, in the present embodiment, the insulating component 26 is interposed between the load side shaft 23 a and the anti-load side shaft 23 b, and the insulating component 26 is integrated with the resin portion 24. The insulating component 26 insulates the load side shaft 23a and the anti-load side shaft 23b and suppresses the shaft current, thereby suppressing the occurrence of electrolytic corrosion of the anti-load side rolling bearing 21b and the load side rolling bearing 21a. .

  Further, by providing a step portion 24e between the central cylindrical portion 24g of the resin portion 24 formed on the outer periphery of the central portion of the shaft 23 and the bearing contact surface 24d, the shaft 23, the resin magnet 22 of the rotor, and When the position detecting resin magnet 25 is integrally formed of resin, when the bearing contact surface 24d of the central cylindrical portion 24g of the resin portion 24 is formed of ileco, the step portion 24e is formed of the eleco. Therefore, since the mating surface of the mold is the anti-load side end surface 24h of the central cylinder portion 24g, the anti-load side rolling bearing 21b is the anti-load that becomes the mating surface of the mold even if burrs occur on the mating surface of the mold. Since the stepped portion 24e is separated from the side end face 24h, the burr does not contact the anti-load side rolling bearing 21b. Therefore, there is little possibility of adversely affecting the anti-load side rolling bearing 21b.

  Further, when the rotor 20 receives a thermal shock, the central cylindrical portion 24g of the resin portion 24 may break, but a stepped portion 24e is provided in the central cylindrical portion 24g, and the radial direction of the central cylindrical portion 24g between the stepped portions 24e. Can be dealt with by increasing the thickness.

  Moreover, like the rotor 20a of the modification 1 shown in FIG. 26, the center hole 23g is formed in the both ends of the shaft 23-1, and it fits in the center hole 23g of the shaft 23-1 in a metal mold | die (upper mold). Protrusions that are confined and secured coaxially with the shaft inserts of the upper mold and the lower mold are provided. When the shaft 23-1, the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24, the protrusion of the mold (upper mold) becomes the center hole 23g of the shaft 23-1. The degree of coaxiality between the rotor resin magnet 22 and the shaft 23-1 can be improved.

  Moreover, like the rotor 20b of the modification 2 shown in FIG. 27, the concave portion 26-1a for shaft insertion provided on both end faces of the insulating component 26-1 has a tapered shape whose diameter decreases from the opening toward the bottom. The ends of the load-side shaft 23-2a and the anti-load-side shaft 23-2b on the insulating component 26-1 side are also tapered corresponding to the taper of the recess 26-1a. Thereby, the shaft 23-2 (the load side shaft 23-2a, the anti-load side shaft 23-2b, the insulating component 26-1), the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated by the resin portion 24. (Molding) by fitting into the end of the insulating component 26-1 side of the load side shaft 23-2a and the anti-load side shaft 23-2b in the tapered recess 26-1a of the insulating component 26-1. The coaxiality of the load side shaft 23-2a and the anti-load side shaft 23-2b can be improved.

  Moreover, like the rotor 20c of the modification 3 shown in FIG. 30, it is set as the structure which assembles the insulation components 26-2, the load side shaft 23-3a, and the anti-load side shaft 23b-3 with a screw, and the shaft 23-3. (Load side shaft 23-3a, anti-load side shaft 23b-3, insulating component 26-2), the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) in the resin portion 24. The coaxiality of the load side shaft 23-3a and the anti-load side shaft 23b-3 is improved by assembling the insulating component 26-2, the load side shaft 23-3a and the anti-load side shaft 23b-3 with screws. Take possible.

  Moreover, like the rotor 20d of the modification 4 shown in FIG. 33, the part where the insulating component 26-3 of the load side shaft 23-4a and the anti-load side shaft 23-4b is assembled is the meat of the insulating component 26-3. By cutting only the thickness, the diameter (center portion) of the load side shaft 23-4a and the anti-load side shaft 23-4b and the diameter of the insulating component 26-3 are approximately the same, so that the shaft 23-4 (load side) When the shaft 23-4a, the anti-load side shaft 23-4b, the insulating component 26-3), the rotor resin magnet 22 and the position detecting resin magnet 25 are integrated (molded) by the resin portion 24, the insulating component 26 By ensuring the thickness of the resin portion 24 formed around -3, it is possible to improve the quality of the rotor 20d. In addition, the end of the insulating component 26-3 is brought into contact with the ends of the load side shaft 23-4a and the anti-load side shaft 23-4b to perform axial positioning, thereby improving the quality of the rotor 20d. Can take.

  Further, as in the rotor 20e of the fifth modification shown in FIG. 36, the insulating component 26-4 is substantially cylindrical and the shaft assembly portion is a through hole 26-4a, so that the shaft 23-5 ( When the load side shaft 23-5a, the anti-load side shaft 23-5b, the insulating component 26-4), the resin magnet 22 of the rotor and the resin magnet 25 for position detection are integrated (molded) by the resin portion 24, insulation is performed. The through hole 26-4a of the component 26-4 is formed in one of the upper and lower molds for molding the insulating component 26-4, and the insulating component fitting portion 23- of the load side shaft 23-5a is formed in the through hole 26-4a. It is possible to improve the coaxiality of the load side shaft 23-5a and the antiload side shaft 23-5b by assembling the 5c and the insulating part fitting portion 23-5d of the antiload side shaft 23-5b. Become.

  Further, like the rotor 20f of the modified example 6 shown in FIG. 39, the insulating component 26-5 has a substantially cylindrical shape that is slightly smaller than the outer diameters of the load side shaft 23-6a and the anti-load side shaft 23-6b. By providing the flange portion 26-5e (FIG. 41) projecting to the outer diameter substantially the same as the outer diameter of the load side shaft 23-6a and the anti-load side shaft 23-6b at the center portion, the shaft 23-6 (Load side shaft 23-6a, anti-load side shaft 23-6b, insulating component 26-5), resin magnet 22 of the rotor and resin magnet 25 for position detection are integrated (molded) in the resin portion 24. The thickness of the resin portion 24 formed around the insulating component 26-5 is substantially uniform, and the strength of the resin portion 24 is ensured while preventing defects such as sinks in the resin portion 24, and the quality of the rotor 20f is improved. It is possible to plan You have me. Further, the ends of the load side shaft 23-6a and the anti-load side shaft 23-6b are brought into contact with the flange portion 26-5e of the insulating component 26-5 to perform axial positioning, thereby improving the quality of the rotor 20f. Can be achieved.

  In addition, when the motor is operated using an inverter, the carrier frequency of the inverter is set higher for the purpose of reducing the noise of the motor. However, as the carrier frequency is set higher, the shaft of the motor is increased. In addition, the shaft voltage generated based on the high-frequency induction increases, and the potential difference existing between the inner ring and the outer ring of the rolling bearing supporting the shaft increases, so that the current flowing through the rolling bearing also increases. Therefore, the rotor 20 of the present embodiment is particularly effective for reducing the shaft current when the electric motor 100 is operated using an inverter. Here, a method of detecting using the Hall IC 49b which is a sensor for detecting the magnetic pole of the position detection resin magnet 25 of the rotor 20 has been described. However, the drive circuit 200 is driven by the electric motor without using the position detection resin magnet 25. The same effect can be obtained in a sensorless drive system that is provided outside of 100, detects the current flowing through the coil with a current detector (not shown), and operates the motor 100 using a microcomputer or the like in the waveform generation circuit 120. Needless to say.

  Further, according to the manufacturing process shown in FIG. 43, when the resin magnet 22 of the rotor, the shaft 23 on which the insulating component 26 is assembled, and the position detection resin magnet 25 are integrated with the resin (resin portion 24), Since all the parts are set in a mold and resin-molded, the cost of the rotor 20 can be reduced by reducing the work process.

  Further, the pedestal 22b of the rotor resin magnet 22 enables the position detection resin magnet 25 to be separated from the end surface of the rotor resin magnet 22, and the thickness of the position detection resin magnet 25 is minimized and arbitrary. The cost can be reduced by filling a thermoplastic resin that is cheaper than the resin magnet 22 of the rotor.

  Further, since the position detecting resin magnet 25 is symmetrical in the thickness direction, it can be set in the mold without matching the orientation.

  In addition, since the portion through which the outer diameter passes when setting the lower mold position detection resin magnet 25 is tapered (tapered portion 24b of the resin portion 24), the lower die position detecting resin magnet 25 is set without being caught by the lower die. Therefore, the cost can be reduced with the improvement of productivity by simplifying the work process.

  Further, when the position detecting resin magnet 25 is set in the lower mold, the inner diameter is held by the inner diameter pressing portion provided in the lower mold, thereby ensuring the accuracy of the coaxiality between the shaft 23 and the resin magnet 22 of the rotor. Is done.

  Further, the notch holding portion provided in the upper mold presses the notch 22a provided in the inner diameter of the resin magnet 22 of the rotor, so that the accuracy of the coaxiality between the shaft 23 and the resin magnet 22 of the rotor is ensured. .

Embodiment 2. FIG.
FIG. 44 is a diagram illustrating the second embodiment, and is a configuration diagram of the air conditioner 300.

  The air conditioner 300 includes an indoor unit 310 and an outdoor unit 320 connected to the indoor unit 310. The indoor unit 310 is equipped with an indoor unit blower (not shown), and the outdoor unit 320 is equipped with an outdoor unit blower 330.

  The outdoor unit blower 330 and the indoor unit blower include the electric motor 100 of the first embodiment as a drive source.

  The durability of the air conditioner 300 is improved by mounting the electric motor 100 of the first embodiment on the outdoor unit blower 330 and the indoor unit blower that are main components of the air conditioner 300.

  As an application example of the electric motor 100 of the present invention, the electric motor 100 can be used by being mounted on a ventilation fan, a home appliance, a machine tool, or the like.

  DESCRIPTION OF SYMBOLS 10 Mold stator, 10a Inner peripheral part, 10b Opening part, 11 Bearing support part, 11a Hole, 20 Rotor, 20-1 Rotor resin assembly, 20a Rotor, 20-1a Rotor resin assembly, 20b Rotor, 20-1b Rotor Resin Assembly, 20c Rotor, 20-1c Rotor Resin Assembly, 20d Rotor, 20-1d Rotor Resin Assembly, 20e Rotor, 20-1e Rotor Resin Assembly, 21a Load-side Rolling Bearing, 21a-1 inner ring, 21a-2 outer ring, 21a-3 rolling element, 21b anti-load side rolling bearing, 21b-1 inner ring, 21b-2 outer ring, 21b-3 rolling element, 22 rotor resin magnet, 22a notch, 22b Pedestal, 22c Positioning protrusion, 23 Shaft, 23a Load side shaft, 23b Anti-load side shaft, 23g Center hole, 23 1 shaft, 23-1a load side shaft, 23-1b anti-load side shaft, 23-2 shaft, 23-2a load side shaft, 23-2b anti load side shaft, 23-3 shaft, 23-3a load side shaft, 23-3b Anti-load-side shaft, 23-3c Threaded portion, 23-3d Threaded portion, 23-4 shaft, 23-4a Load-side shaft, 23-4b Anti-load-side shaft, 23-4c Insulating part fitting portion, 23 -4d Insulating part fitting part, 23-5 shaft, 23-5a Load side shaft, 23-5b Anti-load side shaft, 23-5c Insulating part fitting part, 23-5d Insulating part fitting part, 23-6 shaft 23-6a Load side shaft, 23-6b Anti-load side shaft, 23-6c Insulation part fitting recess, 23-6d Insulation part fitting recess, 24 trees Part, 24a inner diameter pressing part, 24b taper part, 24c resin injection part, 24d abutting surface, 24g central cylinder part, 24j rib, 24k cavity, 25 position detection resin magnet, 25a rib, 25b step, 26 insulation part, 26a Concave part, 26b convex part, 26b-1 apex, 26c gate cutting part, 26-1 insulating part, 26-1a concave part, 26-1b convex part, 26-1c gate cutting part, 26-2 insulating part, 26-2a concave part , 26-2b convex part, 26-2c gate cutting part, 26-2d screw part, 26-3 insulating part, 26-3a concave part, 26-3b convex part, 26-3c gate cutting part, 26-4 insulating part, 26-4a Through hole, 26-4b Convex part, 26-4c Gate cutting part, 26-5 Insulating part, 26-5b Convex part, 26-5c Gate cutting part, 26 5d Shaft part, 26-5e collar part, 30 bracket, 30a bearing support part, 30b press-fit part, 40 stator, 41 stator core, 41a teeth, 42 coil, 43 insulation part, 44 terminal, 44a power supply terminal, 44b Sex point terminal, 45 substrate, 46 lead wire lead part, 47 lead wire, 48 prismatic, 49a IC, 49b Hall IC, 50 mold resin, 100 motor, 110 position detection circuit, 120 waveform generation circuit, 130 pre-driver circuit, 140 Power circuit, 141 transistor, 142 diode, 200 drive circuit, 300 air conditioner, 310 indoor unit, 320 outdoor unit, 330 blower for outdoor unit, 400 electric motor, 500 electric motor.

Claims (17)

In the rotor of the electric motor in which the magnet and the shaft of the rotor are integrated by the resin portion, and rolling bearings are arranged on both axial end surfaces of the resin portion formed on the outer periphery of the shaft,
The shaft includes a load-side shaft, an anti-load-side shaft, and a resin insulating component provided between the load-side shaft and the anti-load-side shaft. .   The rotor of an electric motor according to claim 1, wherein the insulating part has a substantially cylindrical shape, and has recesses to which the load side shaft or the anti-load side shaft is assembled at both ends.   The rotor of an electric motor according to claim 2, wherein the recess of the insulating component has a substantially D-shaped cross section.   The rotor of an electric motor according to claim 2, wherein the recess of the insulating component has a tapered shape whose outer diameter decreases from the opening of the recess toward the bottom.   The said recessed part of the said insulation component is provided with the thread part, and the said load side shaft and the said anti-load side shaft are provided with the thread part corresponding to the thread part of the said recessed part of the said insulation part in the edge part. The motor rotor described.   6. The electric motor according to claim 1, wherein the insulating component includes a plurality of convex portions formed in a circumferential direction of an outer peripheral surface and having apexes in the vicinity of a substantially central portion in an axial direction. Rotor. The convex portion of the insulating component is
First, a position at a predetermined distance from the outer peripheral surface of the insulating component is the apex, and extends to the outer peripheral surface at substantially equal angles on both sides with respect to a line connecting the apex and the center of the outer peripheral circle of the insulating component. ,
2ndly, it is the structure which faces the said outer peripheral surface of the said insulation component in the axial direction at a predetermined angle from the said vertex, The rotor of the motor of Claim 6 characterized by the above-mentioned.   The insulating component extends in the axial direction with a predetermined width on an outer periphery, and includes a gate cutting portion of a resin injection port having a predetermined height, and the gate cutting portion is embedded in the resin portion and serves as a detent. The rotor of the electric motor according to any one of claims 1 to 7.   9. The rotor of an electric motor according to claim 1, wherein the material of the insulating component is a resin material having a linear expansion coefficient substantially the same as that of iron.   10. The motor rotor according to claim 9, wherein the material of the insulating component is a thermosetting resin BMC (bulk molding compound) resin.   The electric motor rotor according to claim 9, wherein the material of the insulating component is a thermoplastic resin blended with a glass filler.   The rotor of an electric motor according to any one of claims 1 to 11, wherein a center hole is provided at an end of the shaft.   At the end of the load side shaft or the anti-load side shaft where the insulating part is assembled, the thickness of the insulating part is cut, and the center part of the load side shaft or the anti-load side shaft and the insulating part The rotor of the electric motor according to claim 1, wherein the outer diameters of the motors are substantially the same.   An electric motor using the rotor of the electric motor according to claim 1. A position detection circuit for detecting the magnetic pole of the rotor using a position detection element;
A waveform generation circuit for generating a PWM (Pulse Width Modulation) signal for driving the inverter based on a speed command signal for instructing the rotation speed of the rotor and a position detection signal from the position detection circuit;
A pre-driver circuit that generates a drive signal from the output of the waveform generation circuit;
15. The electric motor according to claim 14, further comprising: an inverter type drive circuit comprising a power circuit having an arm in which a transistor and a diode are connected in parallel and these are connected in series.   An air conditioner using the electric motor according to claim 14 or 15 as an electric motor for a blower. In the method of manufacturing a rotor of an electric motor in which a magnet and a shaft of a rotor are integrated by a resin portion, and rolling bearings are arranged on both axial end surfaces of the resin portion formed on the outer periphery of the shaft,
An insulating part is inserted between a load side shaft and an anti-load side shaft of the shaft, and the insulating part is integrated and fixed by the resin part.

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