Rotary electric machine

Abstract

The purpose of the present invention is to provide a rotary electric machine in which cooling of a coil end is improved. This rotary electric machine is characterized in that: the rotary electric machine has at least one refrigerant discharge pipe which is disposed on an upper side in a vertical direction of a stator; the refrigerant discharge pipe has a first piping part which supplies a refrigerant into the refrigerant discharge pipe, a second piping part which supplies the refrigerant supplied from the first piping part in an axial direction, and a communication part through which the first piping part and the second piping part communicate with each other; the first piping part has a first flow path which is a flow path of the refrigerant supplied from the outside; the second piping part has a second flow path which supplies the refrigerant from the first flow path to one side in the axial direction via the communication part, a third flow path which supplies the refrigerant from the first flow path to the other side in the axial direction via the communication part, a first discharge port which discharges the refrigerant from the second flow path to a first coil end, and a second discharge port which discharges the refrigerant from the third flow path to a second coil end; and the first piping part is inclined with respect to the second piping part.

Description

rotating electrical machines

[0001] The present invention relates to a rotating electric machine.

[0002] Conventionally, structures for cooling a rotating electric machine have been known. Patent Document 1 discloses a cooling structure for a rotating electric machine in which a through hole is provided in a starter core of the rotating electric machine so that cooling oil flows from one axial side of the through hole to the other axial side, thereby supplying cooling oil to coil ends at both ends of the starter core.

[0003] JP 2012-5180 A

[0004] In the cooling structure of Patent Document 1, a pipe provided on one axial side of the through hole of the stator core is provided with a discharge hole that discharges cooling oil to the coil end on one axial side, and a pipe provided on the other axial side of the through hole of the stator core is provided with a discharge hole that discharges cooling oil to the coil end on the other axial side. Cooling oil is supplied from one axial end of the pipe on one axial side and flows into the through hole of the stator core and the pipe on the other axial side.

[0005] As a result, a difference in pressure loss occurs between the upstream and downstream sides of the cooling oil flow path formed by the pipe on one axial side, the through hole in the stator core, and the pipe on the other axial side, which causes a difference in the amount of cooling oil discharged from the discharge hole of the pipe on one axial side and the discharge hole of the pipe on the other axial side, resulting in the problem that the coil ends on both axial ends of the stator core cannot be cooled evenly.

[0006] In order to ensure a sufficient discharge volume also at the discharge hole of the pipe on the other axial side, it is possible to increase the output of the pump that supplies cooling oil from one axial end of the pipe on one axial side, but this would result in problems such as an increase in the size of the pump, increased costs, and worsening electricity consumption.For this reason, there has traditionally been room for improvement in cooling of the coil ends.

[0007] The present invention has been made in view of the above-mentioned points, and has an object to provide a rotating electric machine with improved cooling of the coil ends.

[0008] A rotating electric machine according to one aspect of the present invention includes a stator core, a stator having a first coil end protruding from one axial end of the stator core and a second coil end protruding from the other axial end of the stator core, a rotor disposed radially inside the stator and facing the stator across an air gap, and at least one refrigerant discharge pipe disposed vertically above the stator, the refrigerant discharge pipe including a first piping section that supplies refrigerant into the refrigerant discharge pipe, a second piping section that supplies the refrigerant supplied from the first piping section in the axial direction, and a second piping section that supplies the refrigerant from the first piping section in the axial direction. and a communication portion that communicates the first piping portion with the second piping portion, the first piping portion having a first flow path that is a flow path for refrigerant supplied from an outside, the second piping portion having a second flow path that supplies refrigerant from the first flow path to one axial side via the communication portion, a third flow path that supplies refrigerant from the first flow path to the other axial side via the communication portion, a first discharge port that discharges refrigerant from the second flow path to the first coil end, and a second discharge port that discharges refrigerant from the third flow path to the second coil end, and the first piping portion is inclined with respect to the second piping portion.

[0009] According to one aspect of the present invention, it is possible to provide a rotating electric machine with improved cooling of the coil ends.

[0010] It is a side cross-sectional view of the motor 10 according to the first embodiment of the present invention. It is a plan view showing an upper part of the stator 200 from the motor 10 excluding the motor frame 100. It is a partial perspective view showing the vicinity of the refrigerant tank 600. It is a diagram showing the refrigerant discharge pipe 510.

[0011] Hereinafter, a rotating electric machine according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0012] <Embodiment 1> Fig. 1 is a side cross-sectional view of a motor 10 according to Embodiment 1 of the present invention. The motor 10 rotates around a shaft 400 extending along a central axis J as a rotation axis. The motor 10 is an example of a rotating electric machine. Fig. 1 is a side cross-sectional view of the motor 10 cut along a plane that passes through the central axis J and is parallel to the direction in which the central axis J extends and the vertical direction.

[0013] In addition, in the drawings, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. In the XYZ coordinate system, the Y axis direction is parallel to the axis of the central axis J shown in Figure 1. The Z axis direction is the vertical direction in Figure 1, among the radial directions relative to the central axis J. The X axis direction is perpendicular to both the Y axis direction and the Z axis direction. In each of the X axis direction, the side indicated by the arrow in the drawing is the positive side, and the opposite side is the negative side.

[0014] In the following description, the positive side in the Y-axis direction (+Y side) will be referred to as "one side," and the negative side in the Y-axis direction (-Y side) will be referred to as "the other side." Note that "one side" and "the other side" are names used merely for the purpose of explanation and do not limit the actual positional relationship or direction. Unless otherwise specified, the direction parallel to the central axis J (Y-axis direction) will be referred to simply as "axial direction," the radial direction centered on the central axis J will be referred to simply as "radial direction," and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J, will be referred to simply as "circumferential direction." In the radial direction, the side closer to the central axis J will be referred to as "radially inner," and the side away from the central axis J will be referred to as "radially outer." In the circumferential direction, the clockwise side when viewed from the -Y side to the +Y side will be referred to as "one circumferential side," and the counterclockwise side will be referred to as "the other circumferential side."

[0015] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction but also extending in a direction tilted by less than 45° with respect to the axial direction. In addition, in this specification, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction, but also extending in a direction tilted by less than 45° with respect to the radial direction. Furthermore, "parallel" includes not only being strictly parallel but also being tilted by an angle of less than 45° with respect to the direction perpendicular to the axial direction. Furthermore, "extending in a direction perpendicular to the axial direction" includes not only extending in a direction strictly perpendicular to the axial direction but also extending in a direction tilted by less than 45° with respect to the direction perpendicular to the axial direction.

[0016] Motor 10 has a stator 200, a rotor 300 disposed radially inside stator 200 across an air gap, and a shaft 400 fixed to the radially inside of rotor 300 and extending along central axis J. Stator 200 has a stator core 210, a first coil end 230 protruding axially to one side from one axial end of stator core 210, and a second coil end 220 protruding axially to the other side from the other axial end of stator core 210.

[0017] The motor 10 also has a motor frame 100 that covers the stator 200 from the radially outer side. The motor frame 100 covers the stator 200 from the radially outer side, thereby accommodating the stator 200, the rotor 300, and the shaft 400.

[0018] Furthermore, the motor 10 has a refrigerant discharge pipe 510 (see FIG. 2 ) and a refrigerant discharge pipe 520 that discharge the refrigerant toward the stator 200, and a refrigerant tank 600 that temporarily stores the refrigerant and allows it to flow vertically downward. The refrigerant discharge pipe 510, the refrigerant discharge pipe 520, and the refrigerant tank 600 are provided within the stator 200 and vertically above the stator 200. The refrigerant is, for example, cooling oil. The refrigerant supplied to the stator 200 cools the stator 200. In this embodiment, the Z direction is the vertical direction, and the refrigerant supplied to the stator 200 from the refrigerant discharge pipe 510, the refrigerant discharge pipe 520, and the refrigerant tank 600 flows toward the +Z side and is stored in an oil pan (not shown) provided vertically below the motor frame 100. The refrigerant stored in the oil pan is pumped up by a pump 700, cooled in an oil cooler (not shown), and then returned to the refrigerant discharge pipes 510 and 520. The refrigerant discharge pipes 510 and 520 are made of, for example, iron or resin.

[0019] 2 is a plan view showing the upper part of the stator 200 of the motor 10, excluding the motor frame 100. The refrigerant discharge pipe 510 is disposed offset to one side in the circumferential direction from directly above the central axis J, and the refrigerant discharge pipe 520 is disposed offset to the other side in the circumferential direction from directly above the central axis J. The refrigerant discharge pipe 510 and the refrigerant discharge pipe 520 extend parallel to the axial direction. In this embodiment, two discharge pipes, the refrigerant discharge pipe 510 and the refrigerant discharge pipe 520, are provided, but the present invention is not limited to this, and it is sufficient to provide at least one refrigerant discharge pipe.

[0020] 3 is a partial perspective view showing the vicinity of refrigerant tank 600. Refrigerant tank 600 is disposed directly above central axis J, circumferentially between refrigerant discharge pipe 510 and refrigerant discharge pipe 520. Refrigerant tank 600 has a storage portion 610, a recessed portion 620, a through hole 621, a through hole 622, and a through hole 623.

[0021] The storage portion 610 is a recess that temporarily stores the refrigerant discharged from the refrigerant discharge pipe 510 and the refrigerant discharge pipe 520. The storage portion 610 has a constant depth except for the portion where the recess portion 620 is formed. The bottom surface of the storage portion 610 is perpendicular to the Z-axis direction. The recess portion 620 is a long, narrow recess formed in the bottom of the storage portion 610 in the X-axis direction. The recess portion 620 has a constant depth except for the portion where the through hole 621, the through hole 622, or the through hole 623 is formed. The through hole 621, the through hole 622, and the through hole 623 are all cylindrical holes that penetrate the bottom of the recess portion 620 in the Z-axis direction. The through hole 621, the through hole 622, and the through hole 623 are all formed to cool the first coil end 230 and the like by flowing the refrigerant temporarily stored in the storage portion 610 downward.

[0022] The refrigerant discharge pipe 510 and the refrigerant discharge pipe 520 are both pipes through which a refrigerant flows. The refrigerant discharge pipe 510 and the refrigerant discharge pipe 520 each have holes for discharging the refrigerant that cools the motor 10 to the reservoir 610, the stator core 210, the first coil end 230, the second coil end 220, etc. The positions, shapes, dimensions, etc. of these holes are not particularly limited.

[0023] 4A and 4B are diagrams showing the refrigerant discharge pipe 510. Fig. 4A is a side view of the refrigerant discharge pipe 510 as seen from the -X side. Fig. 4B is a side cross-sectional view of the refrigerant discharge pipe 510 in Fig. 4A, cut along a plane that passes through the pipe axis of the refrigerant discharge pipe 510 extending in the Y-axis direction and is perpendicular to the X-axis direction. The structure of the refrigerant discharge pipe 520 is the same as that of the refrigerant discharge pipe 510, so only the refrigerant discharge pipe 510 will be described here.

[0024] The refrigerant discharge pipe 510 has a first piping section 512 that supplies the refrigerant into the refrigerant discharge pipe 510, a second piping section 511 that supplies the refrigerant in the axial direction, and an attachment section 513 for fixing the refrigerant discharge pipe 510 to the motor frame 100. The refrigerant discharge pipe 510 is fixed within the motor frame 100 by attaching the attachment section 513 to the upper vertical side within the motor frame 100.

[0025] The first piping section 512 has a supply port 512a through which refrigerant is supplied from the outside and a first flow path 512b through which the refrigerant supplied from the supply port 512a flows. The second piping section 511 has a second flow path 511a through which the refrigerant is supplied to one axial direction and a third flow path 511b through which the refrigerant is supplied to the other axial direction. The second flow path 511a and the third flow path 511b may have the same flow path diameter or different flow path diameters. The refrigerant discharge pipe 510 has a communication section 515 through which the first piping section 512 and the second piping section 511 communicate with each other. The communication section 515 connects the first flow path 512b, the second flow path 511a, and the third flow path 511b.

[0026] The second piping portion 511 is not open at both axial ends, and the second flow path 511a is closed at one axial end and the third flow path 511b is closed at the other axial end. The second piping portion 511 has a first outlet port 511c that penetrates from the second flow path 511a to the outside and discharges the refrigerant toward the first coil end 230 and the storage portion 610, and a third outlet port 511d that penetrates from the second flow path 511a to the outside and discharges the refrigerant toward the stator core 210. The second piping portion 511 has a fourth outlet port 511e that penetrates from the third flow path 511b to the outside and discharges the refrigerant toward the stator core 210, and a second outlet port 511f that penetrates from the third flow path 511b to the outside and discharges the refrigerant toward the second coil end 220. That is, the second piping portion 511 has a pair of outlets, namely, a first outlet 511 c that supplies the refrigerant to the first coil end 230 and a second outlet 511 f that supplies the refrigerant to the first coil end 230 .

[0027] With this configuration, the refrigerant branches into a second flow path 511a directed toward the first outlet port 511c on one axial side and a third flow path 511b directed toward the second outlet port 511f on the other axial side at the communication portion 515 of the second piping portion 511. This reduces the pressure difference between the first outlet port 511c and the second outlet port 511f, enabling the first coil end 230 and the second coil end 220 to be cooled evenly.

[0028] The first piping section 512 is inclined with respect to the second piping section 511. Here, "inclined" means that the first piping section 512 and the second piping section 511 are not perpendicular to each other, and the first piping section 512 is inclined to one axial side or the other axial side with respect to the second piping section 511. Therefore, compared to when the first piping section 512 and the second piping section 511 are perpendicular to each other, the flow path area in the communication section 515 can be increased, and pressure loss can be suppressed.

[0029] Furthermore, when the first piping section 512 and the second piping section 511 are perpendicular to each other, the first piping section 512 extends radially outward. In order to supply refrigerant from the outside of the stator 200 in as small a space as possible, the first flow path 512b needs to communicate with a flow path extending perpendicular to the radial direction. In this case, when the first piping section 512 and the second piping section 511 are perpendicular to each other, the passage that supplies refrigerant to the first flow path 512b and the first flow path 512b communicate at a right angle, which increases pressure loss. However, by inclining the first piping section 512 with respect to the second piping section 511, this pressure loss can be suppressed.

[0030] Furthermore, for example, when the length between the communication portion 515 and the second outlet port 511b is shorter than the length between the communication portion 515 and the first outlet port 511c, the first piping portion 512 may be configured to lean toward the other axial side relative to the second piping portion 511. In this manner, the direction of the refrigerant flow in the first flow path 512b can be aligned with the direction of the refrigerant flow in the second flow path 511a, and an increase in pressure loss of the refrigerant flow from the communication portion 515 to the first outlet port 511c can be suppressed.

[0031] Furthermore, when the motor 10 is operated to cool the first coil end 230 and the second coil end 220, it is desirable to fill the insides of the first piping section 512 and the second piping section 511 with refrigerant. In this way, a uniform amount of refrigerant can be supplied to the pair of coil ends, the first coil end 230 and the second coil end 220.

[0032] The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention. For example, the motor 10 may be configured without the refrigerant tank 600. In this case, the refrigerant is discharged from the first discharge port 511c toward the first coil end 230.

[0033] Furthermore, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0034] This application claims priority based on Japanese Patent Application No. 2024-150464, filed on September 2, 2024, and incorporates by reference all the contents of said Japanese Patent Application.

[0035] REFERENCE SIGNS LIST 10... Motor 100... Motor frame 200... Stator 300... Rotor 400... Shaft 510, 520... Refrigerant discharge pipe

Claims

1. A rotor having a stator core, a first coil end protruding from one axial end of the stator core, and a second coil end protruding from the other axial end of the stator core, a rotor arranged radially inside the stator and facing the stator across an air gap, and at least one refrigerant discharge pipe arranged vertically above the stator, wherein the refrigerant discharge pipe has a first piping section that supplies refrigerant into the refrigerant discharge pipe, a second piping section that supplies refrigerant supplied from the first piping section in the axial direction, and a communication section that communicates between the first piping section and the second piping section, and the first piping section has a first flow path that is a flow path for refrigerant supplied from the outside, a second piping section that supplies the refrigerant from the first flow path to one axial side through the communicating section, a third flow path that supplies the refrigerant from the first flow path to the other axial side through the communicating section, a first discharge port that discharges the refrigerant from the second flow path to the first coil end, and a second discharge port that discharges the refrigerant from the third flow path to the second coil end, and the first piping section is inclined with respect to the second piping section.

2. The rotating electric machine according to claim 1, wherein the first piping section and the second piping section are filled with a refrigerant.

3. A rotating electric machine according to claim 1, characterized in that the second piping section has a third discharge port between the first discharge port and the second discharge port, which discharges refrigerant to the stator coil.

4. A rotating electric machine as described in claim 1, characterized in that the length between the communication portion and the second discharge port is shorter than the length between the communication portion and the first discharge port, and the first piping portion is tilted toward the other axial side relative to the second piping portion.

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