Rotating electric machine

Abstract

In a rotating electric machine provided with a rotor and a stator, one of the rotor and the stator has: a groove portion formed on a circumferential surface facing the other of the rotor and the stator and extending in a direction intersecting the circumferential direction; and a covering part made of resin, wherein the covering part made of resin covers the groove part. The groove portion includes a retaining portion formed so that a groove width at a second position farther from the opening in a radial direction than the first position is larger than a groove width at the first position. The anti-falling part clamps the resin material filled in the groove part so as to prevent the covering part from falling off.

Description

Technical Field

[0001] The present invention relates to rotating electrical machines. Background Art

[0002] In the past, as one of the mechanical losses of a rotating electric machine, it is known that there is wind loss caused by the friction resistance between the rotor and the air near the rotor. If there are bumps on the surface of the rotor or stator, the wind loss will become greater. For example, the tooth slots of the stator that accommodate the coils, the grooves formed on the surface of the stator or the surface of the rotor to reduce torque pulsation, etc., generate eddy currents when the rotor rotates, which becomes the main reason for the increase in wind loss. For example, in order to reduce the wind loss of the rotating electric machine, Patent Document 1 also proposes a structure in which a resin covering layer that fills the bumps is formed on the inner circumference of the stator to flatten the inner circumference of the stator.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-185032 Summary of the invention

[0006] Problems to be solved by the invention

[0007] When a resin coating layer is formed on the surface of a stator to suppress wind loss as in Patent Document 1, the resin coating layer is easily peeled off from the surface of the stator due to external forces such as vibration and centrifugal force.

[0008] The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to provide a rotating electric machine capable of suppressing peeling of a resin cover layer for reducing wind loss.

[0009] Means for solving problems

[0010] One embodiment of the present invention is a rotating electric machine having a rotor and a stator. One of the rotor and the stator has: a groove portion formed on a circumferential surface facing the other of the rotor and the stator and extending in a direction intersecting the circumferential direction; and a resin covering portion, the resin covering portion covering the groove portion. The groove portion includes an anti-slip portion, the anti-slip portion being formed such that the groove width at a second position radially farther from the opening than the first position is larger than the groove width at the first position. The anti-slip portion locks the resin material filled in the groove portion to prevent the covering portion from falling off.

[0011] The groove portion may be formed at the tip of the tooth portion of the stator, and the covering portion may be formed over the entire circumference of the inner circumference of the stator.

[0012] In addition, the resin material of the covering portion may further cover the inside of the slots of the stator to insulate the coils arranged in the slots from the stator.

[0013] Furthermore, the tooth grooves may have flow paths for allowing the refrigerant to flow toward the outer diameter side of the coil.

[0014] The groove portion may be formed on the outer circumference of the rotor, and the covering portion may cover at least the groove portion on the outer circumferential surface of the rotor.

[0015] Effects of the Invention

[0016] According to one aspect of the present invention, it is possible to provide a rotating electrical machine capable of suppressing separation of a resin cover layer for reducing wind loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing a configuration example of a rotating electrical machine according to the present embodiment.

[0018] Figure 2 yes Figure 1 A partial enlarged view of .

[0019] Figure 3 yes Figure 2 An enlarged view of the area surrounded by the dotted line. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0021] In the embodiments, for easy understanding of the description, the structure and elements other than the main part of the present invention are simplified or omitted. In addition, in the drawings, the same elements are marked with the same reference numerals. It should be noted that the shapes, sizes, etc. of the elements shown in the drawings are schematically represented and do not represent the actual shapes, sizes, etc.

[0022] In the following description, the direction parallel to the extension direction of the rotation axis Ax is referred to as the axial direction, the circumferential direction centered on the rotation axis Ax is referred to as the circumferential direction, and the radial direction centered on the rotation axis Ax is referred to as the radial direction. In addition, in the following description, "extending in the axial direction" includes not only the case of strictly extending in the axial direction, but also the case of extending in a direction inclined within a range of less than 45° relative to the axial direction. In addition, in this specification, "extending in the radial direction" includes not only the case of strictly extending in the radial direction, that is, the direction perpendicular to the axial direction, but also the case of extending in a direction inclined within a range of less than 45° relative to the radial direction. In addition, "parallel" includes not only the case of strictly parallel, but also the case of being inclined within a range of less than 45° at an angle formed by each other.

[0023] Figure 1 It is a diagram showing a configuration example of a rotating electrical machine according to the present embodiment. Figure 2 yes Figure 1 A partial enlarged view of . Figure 1 , Figure 2It shows the cross section in the direction orthogonal to the rotation axis Ax in the rotating electrical machine.

[0024] Figure 1 The rotating electric machine 1 shown is an inner rotor type electric machine used as an example for a motor for a vehicle, etc. The rotating electric machine 1 includes a rotor 2 and a cylindrical stator 3 arranged on the outer periphery of the rotor 2. Figure 1 , Figure 2 In FIG. 1 , the extension direction of the rotation axis Ax of the rotary electric machine 1 is the direction perpendicular to the paper surface.

[0025] The rotor 2 is, for example, a magnet embedded type or a surface magnet type rotor. The rotor 2 has, for example, a rotor core 4 in which a plurality of electromagnetic steel sheets are stacked in the axial direction and the overall shape is cylindrical. On the rotor core 4, a plurality of permanent magnets (not shown) are arranged in a manner that forms main magnetic poles at equal intervals along the circumferential direction. In addition, a shaft 5 is embedded in the center of the rotor core 4 in a manner that penetrates the rotor core 4 in the axial direction along the rotation axis Ax. The shaft 5 is axially supported by a bearing not shown.

[0026] The outer circumference of the rotor core 4 is provided with axially extending slots 4a to reduce torque pulsation. A plurality of slots 4a are formed in parallel at equal intervals in the circumferential direction of the rotor 2. The plurality of slots 4a may be formed in an oblique shape with respect to the axial direction.

[0027] In addition, a rotor cover layer 6 made of resin is formed on the outer periphery of the rotor core 4. The rotor cover layer 6 covers the outer peripheral surface of the rotor core 4 and the slots 4a, and has the function of filling the gaps in the slots 4a and forming the outer peripheral surface of the rotor 2 into a uniform circular shape when viewed from the axial direction. The rotor cover layer 6 is formed of, for example, a thermosetting resin and is a non-magnetic body that allows magnetic flux to pass.

[0028] The stator 3 accommodates the rotor 2 in a central space portion centered on the rotation axis Ax. That is, the stator 3 is disposed concentrically with the rotor 2 on the outer periphery of the rotor 2 with a small air gap therebetween.

[0029] The stator 3 includes a stator core 7, a coil 8, and a stator cover 9 made of resin. The stator core 7 is formed by punching out Figure 1 The stator core 7 includes a yoke portion 7a formed radially outward over the entire circumference and a plurality of teeth 7b extending radially inward from the inner circumference of the yoke portion 7a.

[0030] A plurality of tooth portions 7b are arranged at equal intervals in the circumferential direction. In addition, tooth slots are formed between adjacent tooth portions 7b. In each tooth slot, a coil 8 is installed along the outer circumference of the rotor 2, for example, in a distributed winding or concentrated winding manner. Thus, on the stator 3, magnetic poles are formed by the coils 8 at equal intervals along the circumferential direction. In the rotating electric machine 1, the magnetic field of the stator 3 is switched in sequence by controlling the current of the coil 8, and an attractive force or a repulsive force with the magnetic field of the stator 3 is generated in the rotor 2. Thus, the rotor 2 rotates around the rotation axis Ax, and the rotating electric machine 1 is driven.

[0031] In addition, if Figure 2 As shown, a flange portion 7c extending circumferentially to both sides is formed at the front end of the tooth portion 7b located radially inward. In addition, a groove 7d extending axially is formed at the front end of the tooth portion 7b on the surface facing the outer periphery of the rotor 2 to reduce torque pulsation.

[0032] The stator covering layer 9 is a resin layer covering the front end of the tooth portion 7b of the stator core 7 and each tooth slot, and is formed of an insulating and non-magnetic resin material (e.g., a thermosetting resin). It should be noted that the resin material of the stator covering layer 9 may be the same as or different from the resin material of the rotor covering layer 6.

[0033] like Figure 2 As shown, the stator cover layer 9 is formed in an annular shape over the entire circumference at a radially inner position of the stator 3. Specifically, on the radially inner side of the stator 3, the front end of the tooth portion 7b and the gap between the adjacent tooth portions 7b are covered by the stator cover layer 9. Moreover, the inner peripheral surface of the stator 3 facing the outer periphery of the rotor 2 is formed into a uniform circular shape by the stator cover layer 9 when viewed from the axial direction.

[0034] Thus, on the inner periphery of the stator 3, the recessed portion of the tooth slot and the groove 7d at the front end of the tooth portion 7b are filled with the resin material of the stator cover layer 9 and are not exposed to the outside, and the inner peripheral surface of the stator 3 becomes uniform in the circumferential direction by the stator cover layer 9. In addition, by covering the inner peripheral side of the stator 3 with the stator cover layer 9 over the entire circumference, it is also possible to suppress the formation of resin burrs at the position of the recessed portion of the tooth slot.

[0035] In addition, the stator covering layer 9 covers the surface of the tooth portion 7b and the surface of the yoke portion 7a in the tooth slot in a thin film shape. Thus, the stator covering layer 9 in the tooth slot plays a role in insulating the stator core 7 and the coil 8. In addition, in each tooth slot, a gap 10 of a predetermined length is provided in the radial direction between the coil 8 and the yoke portion 7a. The gap 10 between the coil 8 and the yoke portion 7a extends in the axial direction and penetrates the stator 3, and functions as a flow path for allowing a refrigerant (such as oil, etc.) for cooling the coil 8 to flow in the axial direction of the stator 3.

[0036] Figure 3 yes Figure 2 An enlarged view of the portion surrounded by the dashed line. The resin material of the stator covering layer 9 is filled in the slot 7d formed in the stator 3. In a cross-section orthogonal to the axial direction, the slot 7d has an anti-disengagement portion 7e, and the anti-disengagement portion 7e is formed such that the slot width w12 at the second position on the outer diameter side, which is farther from the opening than the first position on the inner diameter side, is greater than the slot width w11 at the first position (the width in the direction orthogonal to the radial direction) (w11 < w12). Therefore, when an external force for pulling out toward the inner diameter side is applied to the stator covering layer 9, the resin material of the anti-disengagement portion 7e is caught at the first position where the slot width is narrow and becomes a resistance to the force in the pulling-out direction. Therefore, through the anti-disengagement portion 7e of the slot 7d, it is difficult for the stator covering layer 9 to peel off toward the inner peripheral side of the stator 3.

[0037] Similarly, the resin material of the rotor covering layer 6 is filled in the slot 4a formed in the rotor 2. In a cross-section orthogonal to the axial direction, the slot 4a has an anti-disengagement portion 4b, and the anti-disengagement portion 4b is formed such that the slot width w22 at the second position on the inner diameter side, which is farther from the opening than the first position on the outer diameter side, is greater than the slot width w21 at the first position (the width in the direction orthogonal to the radial direction) (w21 < w22). Therefore, when an external force for pulling out toward the outer diameter side is applied to the rotor covering layer 6, the resin material of the anti-disengagement portion 4b is caught at the first position where the slot width is narrow and becomes a resistance to the force in the pulling-out direction. Therefore, through the anti-disengagement portion 4b of the slot 4a, it is difficult for the rotor covering layer 6 to peel off toward the outer peripheral side of the rotor 2.

[0038] As described above, in the rotating electric machine 1 of the present embodiment, the stator 3 has: a slot 7d formed in the inner peripheral surface facing the rotor 2 and extending in the axial direction intersecting the circumferential direction; and a resin-made stator covering layer 9 covering the slot 7d. By forming the slot 7d, the torque ripple of the rotating electric machine 1 can be suppressed, and by the stator covering layer 9, the inner peripheral surface of the stator 3 becomes uniform in the circumferential direction, and the windage loss caused by the slot 7d and the cogging can be suppressed.

[0039] In addition, the slot 7d includes an anti-disengagement portion 7e, and the anti-disengagement portion 7e is formed such that the slot width w12 at the second position farther from the opening toward the outer side in the radial direction than the first position is greater than the slot width w11 at the first position. The anti-disengagement portion 7e catches the resin material filled in the slot 7d to prevent the stator covering layer 9 from coming off. Thereby, the peeling of the stator covering layer 9 for reducing the windage loss can be suppressed.

[0040] In addition, the rotor 2 has: a slot 4a formed in the outer peripheral surface facing the stator 3 and extending in the axial direction intersecting the circumferential direction; and a resin-made rotor covering layer 6 covering the slot 4a. By forming the slot 4a, the torque ripple of the rotating electric machine 1 can be suppressed, and by the rotor covering layer 6, the outer peripheral surface of the rotor 2 becomes uniform in the circumferential direction, and the windage loss caused by the slot 4a can be suppressed.

[0041] In addition, the groove 4a includes a fall-off prevention portion 4b, which is formed so that the groove width w22 at the second position farther from the opening in the radial direction inward from the first position is larger than the groove width w21 at the first position. The fall-off prevention portion 4b locks the resin material filled in the groove 4a to prevent the rotor cover layer 6 from falling off. Thus, the peeling of the rotor cover layer 6 for reducing wind loss can be suppressed.

[0042] The present invention is not limited to the above-described embodiments, and various improvements and design changes may be made without departing from the gist of the present invention.

[0043] For example, in the above-mentioned embodiment, the case where the rotating electrical machine 1 is a motor is described, but the rotating electrical machine 1 may be a generator.

[0044] In the above embodiment, an example is described in which the grooves having the anti-slipping portion are formed on each of the rotor 2 and the stator 3. However, the grooves having the anti-slipping portion may be formed on either the rotor 2 or the stator 3. Furthermore, in the rotor 2 and the stator 3, only a portion of the grooves in the circumferential direction may have the anti-slipping portion, and not all the grooves may have the anti-slipping portion.

[0045] In addition, the rotor cover layer 6 formed on the rotor 2 may be partially formed at the position of the slot 4 a in the circumferential direction of the rotor core 4 .

[0046] In addition, the shape of the groove having the anti-detachment portion is not limited to the above-mentioned embodiment and Figure 3 For example, the cross-sectional shape of the groove perpendicular to the axial direction may be a wedge shape in which the groove is wide at the inner side and the groove width becomes narrower as it approaches the opening. In addition, the cross-sectional shape of the groove does not necessarily have to be a shape symmetrical with respect to the radial line. For example, a portion protruding inward may be formed only on one side of the groove.

[0047] The embodiments disclosed this time should be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0048] Description of Reference Numerals

[0049] 1 rotating electrical machine, 2 rotor, 3 stator, 4 rotor core, 4a slot, 4b anti-slip portion, 5 shaft, 6 rotor cover, 7 stator core, 7a yoke portion, 7b tooth portion, 7c flange portion, 7d slot, 7e anti-slip portion, 8 coil, 9 stator cover, 10 gap.

Claims

1. A rotating electrical machine comprising a rotor and a stator, wherein: One of the rotor and the stator has: a groove portion formed in a circumferential surface facing the other of the rotor and the stator and extending in a direction intersecting the circumferential direction; and a resin covering portion, the resin covering portion covering the groove portion, The groove portion includes an anti-slip portion, wherein the anti-slip portion is formed such that a groove width at a second position radially farther from the opening than the first position is larger than a groove width at the first position, The anti-dropping portion locks the resin material filled in the groove portion to prevent the covering portion from dropping off.

2. The rotating electrical machine according to claim 1, wherein: The groove is formed at the front end of the tooth of the stator. The covering portion is formed on the entire circumference of the inner circumference of the stator.

3. The rotating electrical machine according to claim 2, wherein: The resin material of the covering portion further covers the inside of the slots of the stator, thereby insulating the coils arranged in the slots from the stator.

4. The rotating electrical machine according to claim 3, wherein: The tooth groove has a flow path for allowing the refrigerant to flow toward the outer diameter side of the coil.

5. The rotating electrical machine according to claim 1, wherein: The groove is formed on the outer circumference of the rotor. The covering portion covers at least the groove portion of the outer peripheral surface of the rotor.

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