JP2023176954A - Rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine capable of suppressing a drop in axial force of a fastening member.SOLUTION: A rotary electric machine 10 includes a stator 12, a vanish 29 provided on the stator 12, and a pair of end brackets 14, 15. The stator 12 has a cylindrical stator core 21 in which a plurality of disc-like electromagnetic steel plates 30 are laminated. The pair of end brackets 14, 15 are arranged at both sides of the stator 12, and also restrain the stator core 21 in an axial direction by being fastened to each other by a stud bolt and a nut N. The stator core 21 includes a welded part 25 at which outer peripheral surfaces of the plurality of electromagnetic steel plates 30 are welded, and a first outer peripheral part 27 being an outer peripheral part of the stator core 21 and being a part with the welded part 25 provided. A gap between the electromagnetic steel plates 30 in the first outer peripheral part 27 is smaller than a gap between the electromagnetic steel plates 30 in other parts. The pair of end brackets 14, 15 give a binding load to the first outer peripheral part 27.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotating electric machine.

Patent Document 1 discloses a motor including a stator and a housing. The stator has a cylindrical stator core and a coil wound around the stator core. The stator core is formed by laminating a plurality of disc-shaped electromagnetic steel plates. The coil is coated with varnish for fixing the coil and the stator core. The stator is fixed to the housing by bolts.

Japanese Patent Application Publication No. 2013-128339

Varnish may penetrate between electrical steel plates. In this case, when the motor reaches a high temperature during operation, the varnish that has entered between the electromagnetic steel plates may creep, which may reduce the axial force of the bolt.

A rotating electric machine for solving the above problems includes a stator having a cylindrical stator core in which a plurality of disc-shaped electromagnetic steel plates are laminated, a resin coating provided on the stator, and a resin paint disposed on the stator core in the axial direction of the stator core. a pair of end brackets arranged on both sides of the stator core and axially restraining the stator core by being fastened to each other by fastening members, the stator core having outer circumferential surfaces of the plurality of electromagnetic steel plates welded together. a welded portion, and a first outer peripheral portion that is an outer peripheral portion of the stator core and is provided with the welded portion, and the gap between the electromagnetic steel plates in the first outer peripheral portion is the same as that in other portions. The gist is that the pair of end brackets is smaller than the gap between the electromagnetic steel plates and applies a restraining load to the first outer peripheral portion.

The gap between the electromagnetic steel plates in the first outer peripheral portion is smaller than the gap between the electromagnetic steel plates in other parts. Therefore, in the first outer peripheral portion, since the resin paint is difficult to penetrate between the electromagnetic steel plates, the amount of resin paint that penetrates between the electromagnetic steel plates is small. Therefore, when restraining the stator core, the pair of end brackets apply a restraining load to the first outer periphery where the amount of resin paint that has penetrated is small, thereby preventing the resin paint from creeping between the electromagnetic steel plates. A decrease in the axial force of the fastening member can be suppressed.

In the rotating electrical machine, each of the pair of end brackets has a bottomed cylindrical shape having an end wall and a cylindrical peripheral wall erected from a peripheral edge of the end wall, and the pair of end brackets each have a bottomed cylindrical shape, and the stator in the axial direction of the stator core. both end portions of are housed in the pair of end brackets, the peripheral wall has an abutment surface on an inner periphery that is recessed than the tip end surface of the peripheral wall, and the abutment surface is in contact with the first outer peripheral portion. They may be in contact with each other.

As a method for suppressing a decrease in the axial force of the fastening member, for example, a coating layer may be provided on the surface of the stator core, and then a resin paint may be provided on the coating layer. In this case, the presence of the coating layer makes it difficult for the resin paint to penetrate between the electromagnetic steel plates, thereby suppressing a decrease in the axial force of the fastening member due to creep of the resin paint that has penetrated between the electromagnetic steel plates. However, with this method, it is necessary to add new materials and processes to prevent the resin paint from penetrating between the electromagnetic steel sheets. In contrast, in the above configuration, the contact surfaces of the pair of end brackets abut against the first outer circumferential portion of the stator core, thereby directly applying a restraining load to the first outer circumferential portion. In this case, the decrease in the axial force of the fastening member can be suppressed without adding any member or process to prevent the resin paint from entering between the electromagnetic steel plates.

In the rotating electric machine, an intervening member is disposed between the first outer circumferential portion of the stator core and the end bracket in the axial direction of the stator core, and the pair of end brackets are connected to the first outer peripheral portion of the stator core through the intervening member. A restraining load may be applied to the outer peripheral portion.

The pair of end brackets apply a restraining load to the first outer peripheral portion of the stator core via an intervening member that is a separate member from the end brackets. Therefore, if the number or position of the welded parts of the stator core is changed, this can be done by simply changing the number or arrangement of intervening members without changing the shape of the end bracket. Therefore, end brackets having the same shape can be used for multiple types of stator cores having different numbers and positions of welded parts.

In the rotating electrical machine, each of the plurality of electromagnetic steel plates has a bent portion bent in the thickness direction, and the bent portion includes a convex portion protruding from the first surface of the electromagnetic steel plate, and a convex portion of the electromagnetic steel plate. the stator core has a concave portion recessed from a second surface that is an opposite surface to the first surface, and the stator core is formed by engaging the convex portion of the electromagnetic steel sheet with the concave portion of the adjacent electromagnetic steel sheet. A plurality of the electromagnetic steel plates have engaging portions that are engaged with each other in a concave and convex manner, and the pair of end brackets are connected to a second outer circumferential portion of the stator core that is a portion where the engaging portions are provided. However, it is not necessary to apply a restraining load.

Since the bent portion creates tension around the bent portion of the electromagnetic steel plate, the gap between the electromagnetic steel plates at the second outer peripheral portion tends to be larger than the gap between the electromagnetic steel plates at other portions. Therefore, in the second outer peripheral portion, the resin paint tends to penetrate between the electromagnetic steel plates, and the amount of resin paint that penetrates between the electromagnetic steel plates tends to increase. Therefore, when restraining the stator core, the pair of end brackets does not apply a restraining load to the second outer periphery where a large amount of resin paint tends to enter, thereby preventing the resin paint that has entered between the electromagnetic steel plates from creeping. It is possible to further suppress a decrease in the axial force of the fastening member.

In the rotating electrical machine, each of the pair of end brackets has a bottomed cylindrical shape having an end wall and a cylindrical peripheral wall erected from a peripheral edge of the end wall, and the pair of end brackets each have a bottomed cylindrical shape, and the stator in the axial direction of the stator core. are housed in the pair of end brackets, the peripheral wall has an abutment surface on its inner periphery that is recessed from the tip end surface of the peripheral wall, and the peripheral wall of at least one of the pair of end brackets is , the contact surface may further include a relief portion recessed from the contact surface, the contact surface may contact the first outer peripheral portion, and the relief portion may face the second outer peripheral portion.

As a method for suppressing a decrease in the axial force of the fastening member, for example, it is possible to provide a coating layer on the surface of the stator core in advance. In this case, the presence of the coating layer makes it difficult for the resin paint to penetrate between the electromagnetic steel plates, thereby suppressing a decrease in the axial force of the fastening member. However, it is necessary to newly provide members and processes to prevent the resin paint from penetrating between the electromagnetic steel plates. In contrast, in the above configuration, by devising the shape of the pair of end brackets that are the members for restraining the stator core, new members and processes are added to make it difficult for the resin paint to enter between the electromagnetic steel plates. Therefore, it is possible to suppress a decrease in the axial force of the fastening member.

Further, by arranging the relief portion provided in the end bracket to face the second outer circumferential portion of the stator core, it is possible to prevent the pair of end brackets from applying a restraining load to the second outer circumferential portion of the stator core. In addition, as a configuration for preventing the pair of end brackets from applying a restraining load to the second outer circumferential portion, for example, it is possible to provide a relief portion recessed than the outer circumferential surface of the stator core on the second outer circumferential portion of the stator core. . However, in this case, it is necessary to change the shapes of both the end bracket and the stator core. On the other hand, when providing a relief part in the end bracket, the pair of end brackets can apply a restraining load to the first outer circumference and apply a restraining load to the second outer circumference without changing the shape of the stator core. Therefore, it is possible to avoid applying a restraining load.

In the above rotating electrical machine, the second outer circumferential portion may have a relief portion that is recessed from an outer circumferential surface of the stator core.
Since the second outer circumferential portion of the stator core has the relief portion that is recessed from the outer circumferential surface of the stator core, it is possible to prevent the pair of end brackets from applying a restraining load to the second outer circumferential portion of the stator core. In this case, even if the number and position of the engaging parts of the stator core are changed, this can be handled by simply changing the number and position of the relief parts of the stator core. Therefore, the end bracket having the same shape can be used for multiple types of stator cores having different numbers and positions of engaging portions.

According to the present invention, a decrease in the axial force of the fastening member can be reduced.

FIG. 1 is a side sectional view showing a rotating electrical machine in an embodiment. It is an exploded perspective view showing a stator and a pair of end brackets in an embodiment. It is a front view showing a stator core in an embodiment. 4 is a sectional view taken along line 4-4 in FIG. 3. FIG. It is a front view showing the 1st end bracket in an embodiment. It is a front view showing a stator core and a first end bracket in an embodiment. FIG. 1 is a side sectional view showing a rotating electrical machine in an embodiment. It is a side sectional view showing the rotating electrical machine in the example of a change. It is a front view which shows the 1st end bracket in the example of a change. FIG. 7 is a front view showing a stator core and a first end bracket in a modified example.

An embodiment of a rotating electric machine will be described below with reference to FIGS. 1 to 7.
As shown in FIG. 1, the rotating electrical machine 10 includes a rotating shaft 11, a stator 12, a rotor 13, and a pair of end brackets 14 and 15.

<Stator>
As shown in FIGS. 1 and 2, the stator 12 includes a cylindrical stator core 21 and a coil 22 wound around the stator core 21. As shown in FIGS. Stator core 21 has a plurality of electromagnetic steel plates 30.

As shown in FIG. 3, the stator core 21 has a cylindrical yoke 23 and a plurality of teeth 24. Teeth 24 extend from yoke 23 toward the inside of yoke 23 in the radial direction. The plurality of teeth 24 are arranged at equal intervals in the circumferential direction of the yoke 23. The coil 22 is wound around the teeth 24. Note that in FIGS. 1 and 2, the coil 22 is illustrated in a simplified manner.

The electromagnetic steel sheet 30 has a disk shape. The electromagnetic steel plate 30 has a disk-shaped yoke component 31 and a plurality of teeth components 32. The teeth forming portion 32 extends from the yoke forming portion 31 toward the radially inner side of the yoke forming portion 31 . The plurality of teeth components 32 are arranged at equal intervals in the circumferential direction of the yoke component 31.

The electromagnetic steel sheet 30 has a plurality of welded parts 33. The electromagnetic steel sheet 30 of this embodiment has eight welded parts 33. The welded portion 33 is a portion recessed from the outer peripheral surface of the electromagnetic steel sheet 30. The plurality of welded parts 33 are arranged at equal intervals in the circumferential direction of the electromagnetic steel sheet 30.

The electromagnetic steel sheet 30 has a plurality of bent portions 34. The electromagnetic steel sheet 30 of this embodiment has eight bent portions 34. The plurality of bent portions 34 are arranged at equal intervals in the circumferential direction of the electromagnetic steel sheet 30. The welded parts 33 and the bent parts 34 are arranged alternately in the circumferential direction of the electromagnetic steel sheet 30. The bent portion 34 is provided in the yoke component 31. The bent portion 34 is located inside the welded portion 33 in the radial direction of the electromagnetic steel sheet 30.

As shown in FIG. 4, the electromagnetic steel sheet 30 has a first surface 30a and a second surface 30b. The first surface 30a and the second surface 30b are each a surface perpendicular to the thickness direction of the electromagnetic steel sheet 30. The second surface 30b is a surface located opposite to the first surface 30a in the thickness direction of the electromagnetic steel sheet 30. The bent portion 34 is formed by bending the electromagnetic steel sheet 30 from the second surface 30b toward the first surface 30a. The bent portion 34 has a convex portion 34a protruding from the first surface 30a of the electromagnetic steel sheet 30, and a concave portion 34b recessed from the second surface 30b of the electromagnetic steel sheet 30.

Note that among the plurality of electromagnetic steel plates 30, one electromagnetic steel plate 30 has a plurality of through holes 35 that penetrate the electromagnetic steel plate 30 in the thickness direction instead of the bent portions 34. In this embodiment, the electromagnetic steel sheet 30 has eight through holes 35. The plurality of through holes 35 are arranged at equal intervals in the circumferential direction of the electromagnetic steel sheet 30. The welded parts 33 and the through holes 35 are arranged alternately in the circumferential direction of the electromagnetic steel sheet 30. The through hole 35 is provided in the yoke component 31. The through hole 35 is located inside the welded portion 33 in the radial direction of the electromagnetic steel sheet 30.

As shown in FIG. 1, the stator core 21 is formed by laminating a plurality of electromagnetic steel sheets 30. The yoke 23 is formed by laminating yoke constituent parts 31 of a plurality of electromagnetic steel sheets 30. The teeth 24 are formed by laminating the teeth constituent parts 32 of a plurality of electromagnetic steel sheets 30. The stacking direction of the electromagnetic steel sheets 30 coincides with the axial direction of the stator core 21. An electromagnetic steel plate 30 having a through hole 35 is arranged at one end in the stacking direction. The outer circumferential surface of the stator core 21 is formed by the outer circumferential surfaces of a plurality of electromagnetic steel plates 30.

As shown in FIG. 2, the welded parts 33 of the plurality of electromagnetic steel sheets 30 are arranged in the stacking direction. The plurality of electromagnetic steel sheets 30 are fixed to each other by welding the welded parts 33 together while being compressed under pressure in the stacking direction. The stator core 21 has a plurality of welded portions 25 in the circumferential direction in which the outer peripheral surfaces of a plurality of electromagnetic steel plates 30 are welded together. The plurality of welds 25 are provided at equal intervals in the circumferential direction of the stator core 21.

As shown in FIG. 4, the bent portions 34 of the plurality of electromagnetic steel sheets 30 are arranged in the stacking direction. The convex portion 34a of the bent portion 34 of the electromagnetic steel sheet 30 is engaged with the recessed portion 34b of the bent portion 34 of the adjacent electromagnetic steel sheet 30 in the stacking direction. In addition, the convex part 34a of the bent part 34 of the electromagnetic steel sheet 30 adjacent in the lamination direction is inserted into the through hole 35 of the electromagnetic steel sheet 30 located at one end in the lamination direction.

As shown in FIG. 3, the stator core 21 has a plurality of engagement portions 26 in the circumferential direction in which a plurality of electromagnetic steel plates 30 are engaged with each other. The plurality of engaging portions 26 are provided at equal intervals in the circumferential direction of the stator core 21. The welded portions 25 and the engaging portions 26 are provided alternately in the circumferential direction of the stator core 21. The engaging portion 26 is located inside the welded portion 25 in the radial direction of the stator core 21 .

Stator core 21 has a plurality of first outer peripheral parts 27 and a plurality of second outer peripheral parts 28. The first outer circumferential portion 27 and the second outer circumferential portion 28 are the outer circumferential portions of the stator core 21, respectively. The outer circumferential portion of the stator core 21 is a portion of the stator core 21 that is located on the outer side in the radial direction than the coil 22, that is, the yoke 23. Note that the outer circumferential surface of the yoke 23, which is the outer circumferential surface of the stator core 21, is a part of the outer circumferential portion of the stator core 21. The first outer peripheral portion 27 is a portion of the outer peripheral portion of the stator core 21 where the welded portion 25 is provided. The second outer peripheral portion 28 is a portion of the outer peripheral portion of the stator core 21 where the engaging portion 26 is provided. The first outer circumferential portions 27 and the second outer circumferential portions 28 exist alternately in the circumferential direction of the stator core 21.

In the drawings, the thickness of the stator core 21 in the axial direction is shown to be the same around the entire circumference of the stator core 21, but in reality, the thickness of the stator core 21 in the axial direction is slightly different in the circumferential direction of the stator core 21. It's different.

As described above, the plurality of electromagnetic steel plates 30 are welded under pressure. Thereby, in the first outer circumferential portion 27, even if the pressurization is released after welding, the state in which the electromagnetic steel sheets 30 are brought close to each other by the welded portion 25 is maintained. Therefore, the gap between the electromagnetic steel plates 30 in the first outer peripheral portion 27 is smaller than the gap between the electromagnetic steel plates 30 in other parts. Here, "the gap between the electromagnetic steel plates 30 in the first outer circumferential portion 27 is small" includes cases where the electromagnetic steel plates 30 are in contact with each other or cases where the electromagnetic steel plates 30 are connected by the welded part 25, etc. This also includes cases where there is no gap between 30 and 30 mm.

In addition, since the size of the gap between the electromagnetic steel plates 30 varies from gap to gap, all the gaps between the electromagnetic steel plates 30 in the first outer peripheral part 27 are smaller than the gaps between the electromagnetic steel plates 30 in other parts. It doesn't necessarily mean that However, when looking at the average size of a plurality of gaps rather than the size of each gap, the gap between the electromagnetic steel plates 30 in the first outer peripheral portion 27 is the same as the gap between the electromagnetic steel plates 30 in other parts. smaller than the gap. Therefore, the thickness of stator core 21 in the axial direction at first outer peripheral portion 27 is thinner than the thickness of stator core 21 at other portions of the outer peripheral portion of stator core 21 .

On the other hand, in a portion other than the first outer circumferential portion 27, when the pressurization is released after welding, the electromagnetic steel plates 30 return to their original state from being brought close to each other, so the gap between the electromagnetic steel plates 30 increases. In particular, since the bent portion 34 creates tension around the bent portion 34 in the electromagnetic steel sheet 30, the gap between the electromagnetic steel sheets 30 tends to increase in the second outer peripheral portion 28. Therefore, the thickness of the stator core 21 in the axial direction at the second outer peripheral portion 28 is thicker than the thickness of the stator core 21 at other portions of the outer peripheral portion of the stator core 21.

In this embodiment, the thickness of the stator core 21 in the axial direction gradually increases from the first outer circumference 27 to the second outer circumference 28 in the circumferential direction of the stator core 21 . In this embodiment, the difference between the axial thickness of the stator core 21 at the first outer circumference 27 and the axial thickness of the stator core 21 at the second outer circumference 28 is about several hundred microns.

As shown in FIGS. 1 and 2, the stator 12 is provided with varnish 29 as a resin paint. In this embodiment, varnish 29 is provided on the outer peripheral surface of stator core 21. The varnish 29 of this embodiment is a rust-preventing varnish for suppressing the formation of rust on the stator core 21. Varnish 29 is provided on the outer circumferential surface of stator core 21 by being applied to the outer circumferential surface of stator core 21 and then dried. Note that when the varnish 29 is applied to the outer circumferential surface of the stator core 21, the varnish 29 is considered to enter between the electromagnetic steel sheets 30 from the outer circumferential surface of the stator core 21. Therefore, among the gaps between the electromagnetic steel plates 30 in the first outer circumferential portion 27, the smaller the gap between the electromagnetic steel plates 30 on the outer circumferential surface of the stator core 21, the more preferable. The smaller the gap between the electromagnetic steel plates 30 on the outer circumferential surface of the stator core 21, the more difficult it becomes for the varnish 29 applied to the outer circumferential surface of the stator core 21 to enter between the electromagnetic steel plates 30.

As shown in FIG. 1, a cylindrical rotor 13 is arranged inside the stator 12. The rotating shaft 11 is fixed to the rotor 13 while being inserted through the rotor 13. The rotating shaft 11 rotates together with the rotor 13.

<Pair of end brackets>
In the following description, one of the pair of end brackets 14 and 15 will be referred to as a first end bracket 14, and the other end bracket 15 will be referred to as a second end bracket 15.

As shown in FIGS. 2 and 5, the first end bracket 14 includes a first end wall 41 as an end wall, and a cylindrical shape extending from the peripheral edge of the first end wall 41 in the thickness direction of the first end wall 41. It has a cylindrical shape with a bottom and a first circumferential wall 42 as a circumferential wall. The first end bracket 14 has a first shaft hole 41a that passes through the first end wall 41 in the thickness direction. The first end bracket 14 has a plurality of first bolt holes 42 a passing through the first peripheral wall 42 . The first end bracket 14 of this embodiment has four first bolt holes 42a. The direction in which the first bolt holes 42a extend corresponds to the direction in which the first peripheral wall 42 extends from the first end wall 41. An opening 42b is provided in the middle of the first peripheral wall 42 in the circumferential direction.

As shown in FIGS. 1 and 5, the first peripheral wall 42 has a plurality of first contact surfaces 43 as contact surfaces on its inner periphery. The first contact surface 43 is a surface that is more concave than the tip surface 421 of the first peripheral wall 42 . The width of the first contact surface 43 in the circumferential direction of the first peripheral wall 42 is larger than the width of the first outer peripheral portion 27 of the stator core 21 in the circumferential direction. Further, the first peripheral wall 42 has a plurality of relief portions 44 on the inner periphery. The relief portion 44 is a portion recessed from the first contact surface 43. The width of the relief portion 44 in the circumferential direction of the first circumferential wall 42 is larger than the width of the second outer circumferential portion 28 of the stator core 21 in the circumferential direction. The first contact surfaces 43 and the relief portions 44 are provided alternately in the circumferential direction of the first peripheral wall 42 . In this embodiment, the depth from the first contact surface 43 to the bottom surface of the relief part 44 is the axial thickness of the stator core 21 at the first outer peripheral part 27 and the axial thickness of the stator core 21 at the second outer peripheral part 28. It's bigger than the difference between the two.

As shown in FIG. 2, the second end bracket 15 includes a second end wall 51 as an end wall, and a cylindrical peripheral wall extending from the peripheral edge of the second end wall 51 in the thickness direction of the second end wall 51. It has a cylindrical shape with a bottom and a second peripheral wall 52 . The second end bracket 15 has a second shaft hole 51a that passes through the second end wall 51 in the thickness direction. The second end bracket 15 has a plurality of second bolt holes 52a provided in the second peripheral wall 52. The second end bracket 15 of this embodiment has four second bolt holes 52a. A female thread is formed on the inner circumferential surface that defines the second bolt hole 52a. The second bolt hole 52a is open at the distal end surface 521 of the second peripheral wall 52. The second peripheral wall 52 has a second contact surface 53 on its inner periphery, which is a contact surface that is recessed from the tip end surface 521 of the second peripheral wall 52 . The second contact surface 53 is provided all around the second peripheral wall 52 .

As shown in FIG. 1, one end of the stator 12 in the axial direction of the stator core 21 is housed in a first end bracket 14, and the other end of the stator 12 in the axial direction of the stator core 21 is housed in a second end bracket. It is housed within 15. Specifically, the first end wall 41 of the first end bracket 14 and the second end wall 51 of the second end bracket 15 are arranged on both sides of the stator 12 in the axial direction of the stator core 21. The first peripheral wall 42 of the first end bracket 14 is located on the outer periphery of the coil 22 at one end of the stator core 21 in the axial direction, and the second peripheral wall 52 of the second end bracket 15 is located at the other end of the stator core 21 in the axial direction. It is located on the outer periphery of the coil 22.

As shown in FIG. 6, the stator core 21 is arranged such that the first outer peripheral part 27 corresponds to the first contact surface 43 and the second outer peripheral part 28 corresponds to the relief part 44 with respect to the first end bracket 14. It is located in The first outer circumferential portion 27 of the stator core 21 is arranged to overlap with the first contact surface 43 of the first end bracket 14 in the axial direction of the stator core 21 . The second outer peripheral portion 28 of the stator core 21 is arranged so as to overlap the relief portion 44 of the first end bracket 14 in the axial direction of the stator core 21 .

As shown in FIG. 1, the first outer peripheral portion 27 of the stator core 21 is located between the first abutment surface 43 and the second abutment surface 53 in the axial direction of the stator core 21. The first outer peripheral portion 27 contacts the first contact surface 43 at one end of the stator core 21 in the axial direction, and contacts the second contact surface 53 at the other end of the stator core 21 in the axial direction.

As shown in FIG. 7, the second outer peripheral portion 28 of the stator core 21 is located between the bottom surface of the relief portion 44 and the second contact surface 53 in the axial direction of the stator core 21. The second outer peripheral portion 28 faces the bottom surface of the relief portion 44 . In this embodiment, a gap exists between the bottom surface of the relief part 44 and the second outer peripheral part 28. The second outer peripheral portion 28 is in contact with the second contact surface 53 of the second end bracket 15 .

As shown in FIG. 2, the first end bracket 14 and the second end bracket 15 are fastened to each other by a stud bolt B and a nut N as fastening members. Specifically, the stud bolt B is inserted into the first bolt hole 42a of the first end bracket 14 and then screwed into the second bolt hole 52a of the second end bracket 15. A washer W is inserted into a portion of the stud bolt B that protrudes from the first end wall 41 of the first end bracket 14, and then a nut N is screwed into the portion. The first end bracket 14 and the second end bracket 15 are fastened to each other by the axial force of the fastening member. The first end bracket 14 and the second end bracket 15 restrain the stator core 21 in the axial direction by being fastened to each other by a fastening member.

As shown in FIG. 1, the first end bracket 14 and the second end bracket 15 apply a restraining load to the first outer peripheral portion 27 of the stator core 21. As shown in FIG. In the present embodiment, the first end bracket 14 and the second end bracket 15 are arranged such that the first contact surface 43 and the second contact surface 53 contact the first outer peripheral portion 27 of the stator core 21 . A restraining load is directly applied to 27. Therefore, the axial force of the fastening member acts on the first outer peripheral portion 27 of the stator core 21 via the first end bracket 14 and the second end bracket 15.

On the other hand, as shown in FIG. 7, the first end bracket 14 and the second end bracket 15 do not apply a restraining load to the second outer peripheral portion 28 of the stator core 21. Therefore, the axial force of the fastening member does not act on the second outer peripheral portion 28 of the stator core 21 .

That is, the first end bracket 14 and the second end bracket 15 constrain the stator core 21 in the axial direction by applying a constraint load to the first outer peripheral portion 27 of the stator core 21.

As shown in FIG. 1, the first end of the rotating shaft 11 is inserted into the first shaft hole 41a. A first end of the rotating shaft 11 is rotatably supported by the first end bracket 14 via a first bearing 16 . A second end of the rotating shaft 11, which is an end opposite to the first end, is inserted into the second shaft hole 51a. A second end of the rotating shaft 11 is rotatably supported by the second end bracket 15 via a second bearing 17.

[Actions and effects of this embodiment]
The operation and effects of this embodiment will be explained.
(1) The stator core 21 is formed by laminating a plurality of electromagnetic steel sheets 30. The stator core 21 has a welded portion 25 in which the outer peripheral surfaces of a plurality of electromagnetic steel plates 30 are welded. Stator core 21 has a first outer circumferential portion 27 that is the outer circumferential portion of stator core 21 and is a portion where welded portion 25 is provided. The gap between the electromagnetic steel plates 30 in the first outer peripheral portion 27 is smaller than the gap between the electromagnetic steel plates 30 in other parts. Therefore, in the first outer circumferential portion 27, since the varnish 29 is difficult to penetrate between the electromagnetic steel plates 30, the amount of the varnish 29 that penetrates between the electromagnetic steel plates 30 is small. Therefore, when the pair of end brackets 14 and 15 restrain the stator core 21, they apply a restraining load to the first outer circumferential portion 27 where the amount of varnish 29 that has penetrated is small. Thereby, it is possible to suppress a decrease in the axial force of the fastening member when the varnish 29 that has entered between the electromagnetic steel plates 30 creeps.

(2) As a method for suppressing a decrease in the axial force of the fastening member, for example, the following first to third methods can be considered.
As a first method, a coating layer is formed on the surface of the stator core 21 before applying the varnish 29 to the stator 12. In this case, the presence of the coating layer makes it difficult for the varnish 29 to penetrate between the electromagnetic steel plates 30, so that the axial force of the fastening member is suppressed from decreasing when the varnish 29 that has penetrated between the electromagnetic steel plates 30 creeps. However, this method requires new members and processes for making it difficult for the varnish 29 to enter between the electromagnetic steel sheets 30.

As a second method, after the pair of end brackets 14 and 15 are fastened together by a fastening member, the varnish 29 that has entered between the electromagnetic steel plates 30 is forced to creep. Then, tighten the fastening member again. In this case, since the pair of end brackets 14 and 15 are fastened after the varnish 29 has creeped, a decrease in the axial force of the fastening member is suppressed. However, this method requires an aging process to force the varnish 29 to creep.

As a third method, when applying the varnish 29 to the stator core 21, the varnish 29 is applied to the area where the axial force of the fastening member does not act, and the varnish 29 is not applied to the area where the axial force acts. Then, after the pair of end brackets 14 and 15 are fastened together by the fastening member, that is, with the axial force of the fastening member acting on the stator core 21, varnish 29 is applied to the area where varnish 29 is not applied. In this case, in the range where the axial force of the fastening member in the stator core 21 acts, the varnish 29 becomes difficult to penetrate between the electromagnetic steel plates 30, so that a decrease in the axial force of the fastening member is suppressed. However, this method complicates the first coating process and requires a second coating process.

In contrast, in the present embodiment, the first end bracket 14 has a bottomed cylindrical shape that has a first end wall 41 and a cylindrical first peripheral wall 42 that stands upright from the peripheral edge of the first end wall 41. It is. The second end bracket 15 has a bottomed cylindrical shape and includes a second end wall 51 and a cylindrical second circumferential wall 52 that stands upright from the peripheral edge of the second end wall 51 . Both ends of the stator 12 in the axial direction of the stator core 21 are housed within a pair of end brackets 14 and 15. The first peripheral wall 42 has a first contact surface 43 on its inner periphery that is recessed from the tip end surface 421 of the first peripheral wall 42 . The second peripheral wall 52 has a second contact surface 53 on the inner periphery that is recessed from the tip surface 521 of the second peripheral wall 52 . The pair of end brackets 14 and 15 apply a restraining load to the first outer circumferential portion 27 by abutting the first abutment surface 43 and the second abutment surface 53 with the first outer circumferential portion 27 . In this case, by devising the shape of the pair of end brackets 14 and 15, which are members for restraining the stator core 21, a decrease in the axial force of the fastening member is suppressed. Therefore, unlike the first method, there is no need to newly provide members and processes for making it difficult for the varnish 29 to enter between the electromagnetic steel sheets 30. Further, it is possible to avoid increasing the number of steps and complicating the steps as in the second method and the third method.

(3) In the stator core 21, a plurality of electromagnetic steel plates 30 are engaged with each other in a concave-convex manner by engaging the convex portion 34a of the bent portion 34 of the electromagnetic steel plate 30 with the concave portion 34b of the bent portion 34 of the adjacent electromagnetic steel plate 30. It has an engaging portion 26. The stator core 21 has a second outer peripheral portion 28 that is the outer peripheral portion of the stator core 21 and is a portion where the engaging portion 26 is provided. Since the bending portion 34 creates a tension around the bending portion 34 in the electromagnetic steel sheet 30, the gap between the electromagnetic steel sheets 30 at the second outer peripheral portion 28 is larger than the gap between the electromagnetic steel sheets 30 at other portions. Cheap. Therefore, in the second outer peripheral portion 28, the varnish 29 easily enters between the electromagnetic steel plates 30, and the amount of varnish 29 that enters between the electromagnetic steel plates 30 tends to increase. Therefore, when the pair of end brackets 14 and 15 restrain the stator core 21, they do not apply a restraining load to the second outer peripheral portion 28, where a large amount of varnish 29 tends to enter. Thereby, it is possible to further suppress a decrease in the axial force of the fastening member when the varnish 29 that has entered between the electromagnetic steel plates 30 creeps.

(4) The first end bracket 14 has a relief portion 44 that is recessed from the first contact surface 43. The relief portion 44 faces the second outer peripheral portion 28 of the stator core 21 . Thereby, the pair of end brackets 14 and 15 can be prevented from applying a restraining load to the second outer peripheral portion 28 of the stator core 21.

Note that as a configuration for preventing the pair of end brackets 14 and 15 from applying a restraining load to the second outer circumferential portion 28, for example, the second outer circumferential portion 28 of the stator core 21 is provided with a relief that is recessed from the outer circumferential surface of the stator core 21. It is conceivable to establish a section. However, in this case, it is necessary to change the shapes of both the first end bracket 14 and the stator core 21. In contrast, in this embodiment, the first end bracket 14 is provided with a relief portion 44 . As a result, the pair of end brackets 14 and 15 can apply a restraining load to the first outer peripheral part 27 of the stator core 21 and restrain the second outer peripheral part 28 without changing the shape of the stator core 21. It is possible to avoid applying any load.

(5) The pair of end brackets 14 and 15 directly apply a restraint load to the first outer peripheral portion 27 of the stator core 21. Therefore, compared to the case where the pair of end brackets 14 and 15 indirectly apply a restraining load to the first outer peripheral part 27 through other members, the restraining load is applied to the first outer peripheral part 27. can be stably provided.

(6) Since the pair of end brackets 14 and 15 are fastened to each other by a plurality of fastening members, they are unlikely to be misaligned. Therefore, the positions at which the pair of end brackets 14 and 15 apply restraint loads to the stator core 21 can be prevented from shifting.

(7) The stator core 21 is restrained by a pair of end brackets 14 and 15. Therefore, rotation of the stator 12 due to a reaction to the output torque of the rotating electric machine 10 can be suppressed.

(8) The electromagnetic steel sheets 30 adjacent in the stacking direction are engaged with each other in a concave and convex manner. Therefore, in the state where the electromagnetic steel plates 30 are stacked before welding, it is possible to suppress the electromagnetic steel plates 30 from being displaced.

[Example of change]
Note that each of the above embodiments can be modified and implemented as follows. The above embodiments and the following modifications can be implemented in combination with each other within a technically consistent range.

In the embodiment described above, the pair of end brackets 14 and 15 directly apply the restraining load to the first outer circumferential portion 27 of the stator core 21, but they may apply the restraining load indirectly.

For example, as shown in FIG. 8, a first intervening member 61 as an intervening member may be disposed between the first end wall 41 and the first outer peripheral portion 27 of the stator core 21 in the axial direction of the stator core 21. good. A second intervening member 62 may be disposed between the second end wall 51 and the first outer peripheral portion 27 of the stator core 21 in the axial direction of the stator core 21 . The pair of end brackets 14 and 15 apply a restraining load to the first outer peripheral portion 27 of the stator core 21 via the first intervening member 61 and the second intervening member 62.

In this case, even if the number or position of the welded portions 25 of the stator core 21 is changed, this can be handled by simply changing the number or arrangement of the first intervening member 61 and the second intervening member 62. Therefore, end brackets 14 and 15 having the same shape can be used for multiple types of stator cores 21 having different numbers and positions of welded portions 25.

Note that it is preferable that the first intervening member 61 is not disposed between the first end wall 41 and the second outer peripheral portion 28 of the stator core 21 in the axial direction of the stator core 21 . It is preferable that the second intervening member 62 is not disposed between the second end wall 51 and the second outer peripheral portion 28 of the stator core 21 in the axial direction of the stator core 21 . In this case, the pair of end brackets 14 and 15 can be prevented from applying a restraining load to the second outer peripheral portion 28 of the stator core 21.

○ The electromagnetic steel sheet 30 does not need to have the bent portion 34. Further, the electromagnetic steel sheet 30 disposed at one end in the stacking direction does not need to have the through hole 35. That is, the stator core 21 does not need to have the engaging portion 26. In this case, the first end bracket 14 does not need to have the relief part 44.

○ The depth from the first contact surface 43 to the bottom surface of the relief portion 44 is greater than or equal to the difference between the axial thickness of the stator core 21 at the first outer circumferential portion 27 and the axial thickness of the stator core 21 at the second outer circumferential portion 28. It is preferable to set it to . The depth from the first contact surface 43 to the bottom surface of the relief part 44 is the same as the difference between the axial thickness of the stator core 21 at the first outer peripheral part 27 and the axial thickness of the stator core 21 at the second outer peripheral part 28 In this case, the second outer peripheral portion 28 of the stator core 21 comes into contact with the bottom surface of the relief portion 44 .

○ Instead of the first end bracket 14, the second end bracket 15 may have a relief portion that is recessed from the second contact surface 53. In this case, the stator core 21 is arranged with respect to the second end bracket 15 such that the second outer peripheral portion 28 faces the relief portion of the second end bracket 15. Thereby, the pair of end brackets 14 and 15 can be prevented from applying a restraining load to the second outer peripheral portion 28 of the stator core 21.

○ Not only the first end bracket 14 but also the second end bracket 15 may have a relief portion recessed from the second contact surface 53. In this case, the stator core 21 is configured such that the second outer peripheral portion 28 faces the relief portion 44 of the first end bracket 14 and the relief portion of the second end bracket 15 with respect to the pair of end brackets 14 and 15. Preferably. Thereby, the pair of end brackets 14 and 15 can be prevented from applying a restraining load to the second outer peripheral portion 28 of the stator core 21.

In the above embodiment, the first end bracket 14 is provided with the relief portion 44 in order to prevent the pair of end brackets 14 and 15 from applying a restraining load to the second outer peripheral portion 28 of the stator core 21. , a relief portion may be provided in the stator core 21.

As shown in FIG. 9, the first contact surface 43 of the first end bracket 14 is provided around the entire circumference of the first peripheral wall 42 excluding the opening 42b. Note that it is not essential that the first contact surface 43 be provided around the entire circumference of the first peripheral wall 42 except for the opening 42b. The first end bracket 14 may have the first contact surfaces 43 and relief portions 44 alternately in the circumferential direction as in the above embodiment.

As shown in FIG. 10 , the second outer circumferential portion 28 of the stator core 21 has a relief portion 70 that is recessed from the outer circumferential surface of the stator core 21 . The first outer peripheral portion 27 of the stator core 21 overlaps the first contact surface 43 in the axial direction of the stator core 21 . On the other hand, the second outer peripheral portion 28 of the stator core 21 does not overlap the first contact surface 43 in the axial direction of the stator core 21 due to the relief portion 70 . Therefore, the pair of end brackets 14 and 15 apply a restraining load to the first outer peripheral part 27 of the stator core 21, and do not apply a restraining load to the second outer peripheral part 28.

In this case, even if the number or position of the engaging parts 26 of the stator core 21 is changed, this can be handled by simply changing the number or position of the relief parts 70 of the stator core 21. Therefore, end brackets 14 and 15 having the same shape can be used for multiple types of stator cores 21 having different numbers and positions of engaging portions 26.

○ The welded portion 33 of the electromagnetic steel sheet 30 does not need to be recessed from the outer peripheral surface of the electromagnetic steel sheet 30.
○ Resin paints are not limited to anti-rust varnishes. The resin paint may be, for example, an adhesive for fixing the stator core 21 and the coil 22.

The resin paint may be provided on areas other than the outer circumferential surface of the stator core 21, such as the inner circumferential surface of the yoke 23 and the side surfaces of the teeth 24. Further, when the resin paint is an adhesive for fixing the stator core 21 and the coil 22, the resin paint may be provided on the coil 22. In this case, the resin paint applied to the coil 22 may adhere to the stator core 21, and the resin paint may enter between the electromagnetic steel plates 30.

○ The fastening member is not limited to the stud bolt B and nut N. The fastening member may be, for example, a bolt having a shaft portion having a male thread on its outer circumferential surface and a head portion at one end of the shaft portion.

DESCRIPTION OF SYMBOLS 10... Rotating electric machine, 12... Stator, 14... First end bracket as an end bracket, 15... Second end bracket as an end bracket, 21... Stator core, 25... Welding part, 26... Engaging part, 27... First Outer peripheral part, 28... Second outer peripheral part, 29... Varnish as resin paint, 30... Electromagnetic steel plate, 30a... First surface, 30b... Second surface, 34... Bent part, 34a... Convex part, 34b... Concave part, 41 ...First end wall as an end wall, 42... First circumferential wall as a peripheral wall, 43... First contact surface as an abutting surface, 44... Relief portion, 51... Second end wall as an end wall, 52... Second peripheral wall as a peripheral wall, 53... Second contact surface as a contact surface, 61... First intervening member as an intervening member, 62... Second intervening member as an intervening member, 70... Relief portion, 421... Tip Surface, 521... tip surface.

Claims (6)

a stator having a cylindrical stator core in which a plurality of disc-shaped electromagnetic steel plates are laminated;
a resin paint provided on the stator;
a pair of end brackets that are arranged on both sides of the stator in the axial direction of the stator core and that are fastened to each other by fastening members to restrain the stator core in the axial direction;
Equipped with
The stator core has a welded portion where the outer peripheral surfaces of the plurality of electromagnetic steel sheets are welded, and a first outer peripheral portion that is the outer peripheral portion of the stator core and is a portion where the welded portion is provided,
The gap between the electromagnetic steel plates in the first outer peripheral portion is smaller than the gap between the electromagnetic steel plates in other parts,
The rotating electric machine, wherein the pair of end brackets apply a restraining load to the first outer peripheral portion. Each of the pair of end brackets has a bottomed cylindrical shape having an end wall and a cylindrical peripheral wall standing upright from a peripheral edge of the end wall,
Both ends of the stator in the axial direction of the stator core are accommodated within the pair of end brackets,
The peripheral wall has an abutment surface on an inner periphery that is recessed from a tip surface of the peripheral wall,
The rotating electric machine according to claim 1, wherein the contact surface is in contact with the first outer peripheral portion. An intervening member is disposed between the first outer peripheral portion of the stator core and the end bracket in the axial direction of the stator core,
The rotating electric machine according to claim 1, wherein the pair of end brackets apply a restraint load to the first outer peripheral portion via the intervening member. Each of the plurality of electromagnetic steel sheets has a bent portion bent in the thickness direction,
The bent portion has a convex portion protruding from a first surface of the electromagnetic steel sheet, and a recessed portion recessed from a second surface of the electromagnetic steel sheet that is a surface opposite to the first surface,
The stator core has an engaging portion in which a plurality of the electromagnetic steel plates are engaged with each other in a concave-convex manner by engaging the convex portions of the electromagnetic steel plates with the concave portions of adjacent electromagnetic steel plates,
The rotating electrical machine according to claim 1, wherein the pair of end brackets do not apply a restraining load to a second outer circumferential portion of the stator core, which is a portion where the engaging portion is provided. Each of the pair of end brackets has a bottomed cylindrical shape having an end wall and a cylindrical peripheral wall standing upright from a peripheral edge of the end wall,
Both ends of the stator in the axial direction of the stator core are accommodated within the pair of end brackets,
The peripheral wall has an abutment surface on an inner periphery that is recessed from a tip surface of the peripheral wall,
The peripheral wall of at least one of the pair of end brackets further has a relief portion recessed from the abutment surface,
The contact surface contacts the first outer peripheral portion,
The rotating electric machine according to claim 4, wherein the relief portion faces the second outer peripheral portion. The rotating electrical machine according to claim 4, wherein the second outer peripheral portion has a relief portion that is recessed than the outer peripheral surface of the stator core.

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