Rotating electric machine

Abstract

To provide a rotating electric machine with improved cooling of the coil ends. [Solution] The stator has at least one refrigerant discharge pipe 510 located vertically above it, and the refrigerant discharge pipe has a first piping section 512 that supplies refrigerant into the refrigerant discharge pipe, a second piping section 511 that supplies the refrigerant supplied from the first piping section in the axial direction, and a connecting section 515 through which the first piping section and the second piping section communicate. The first piping section has a first flow path 512b which is a flow path for refrigerant supplied from the outside, the second piping section has a second flow path 511a that supplies refrigerant from the first flow path to one side in the axial direction via the connecting section, a third flow path 511b that supplies refrigerant from the first flow path to the other side in the axial direction via the connecting section, a first discharge port 511c that discharges refrigerant from the second flow path to the first coil end, and a second discharge port 511f that discharges 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.

Description

Technical Field

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

Background Art

[0002] Conventionally, a structure for cooling a rotating electric machine has been known. Patent Document 1 discloses a cooling structure for a rotating electric machine in which a through hole penetrating axially is provided in a starter core of the rotating electric machine, and cooling oil is caused to flow from one axial side of the through hole toward the other axial side, thereby supplying the cooling oil to the coil ends at both ends of the starter core.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the cooling structure of Patent Document 1, a discharge hole for discharging cooling oil to the coil end on one axial side is provided in a pipe provided on one axial side of the through hole of the stator core, and a discharge hole for discharging cooling oil to the coil end on the other axial side is provided in a pipe provided on the other axial side of the through hole of the stator core. The cooling oil is supplied from one axial end of the pipe on one axial side and flows through the through hole of the stator core and the pipe on the other axial side.

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

[0006] To ensure a sufficient discharge volume at the discharge port of the pipe on the other axial side, it is conceivable to increase the output of the pump supplying cooling oil from the axial end of the pipe on one axial side. However, this would lead to problems such as a larger pump, increased costs, and worsened energy efficiency. For this reason, there has been room for improvement in the cooling of the coil ends.

[0007] The present invention has been made in view of the above points, and aims to provide a rotating electric machine with improved cooling of the coil end. [Means for solving the problem]

[0008] A rotating electric machine according to one aspect of the present invention includes a stator 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 inward of the stator and facing the stator via an air gap, and at least one refrigerant discharge pipe arranged vertically above the stator, wherein the refrigerant discharge pipe includes 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 the first piping The first piping section has a connecting section that connects the first piping section and the second piping section, the first piping section has a first flow path which is a flow path for refrigerant supplied from the outside, the second piping section has a second flow path which supplies refrigerant from the first flow path to one axial side via the connecting section, a third flow path which supplies refrigerant from the first flow path to the other axial side via the connecting section, a first discharge port which discharges refrigerant from the second flow path to the first coil end, and a second discharge port which discharges 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. [Effects of the Invention]

[0009] According to one aspect of the present invention, a rotating electric machine with improved cooling of the coil ends can be provided. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side cross-sectional view of a motor 10 according to Embodiment 1 of the present invention. [Figure 2] This is a plan view showing the upper part of the stator 200, excluding the motor frame 100 from the motor 10. [Figure 3] This is a partial perspective view showing the vicinity of the refrigerant tank 600. [Figure 4] This is a diagram of the refrigerant discharge pipe 510. [Modes for carrying out the invention]

[0011] The following description of a rotating electric machine according to an embodiment of the present invention will be made with reference to the drawings. Note that in the following drawings, the scale and number of components in each structure may differ from the actual structure in order to make the components easier to understand.

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

[0013] Furthermore, in the drawings, the XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system where appropriate. In the XYZ coordinate system, the Y-axis direction is parallel to the axis direction of the central axis J shown in Figure 1. The Z-axis direction is the vertical direction in Figure 1, which is the radial direction with respect to the central axis J. The X-axis direction is perpendicular to both the Y-axis and Z-axis directions. In the X-axis, Y-axis, and Z-axis directions, the side indicated by the arrow in the drawing is the + side, and the opposite side is the - side.

[0014] Furthermore, in the following explanation, 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 merely names used for explanatory purposes and do not limit the actual positional relationship or direction. Also, unless otherwise specified, the direction parallel to the central axis J (Y-axis direction) will be simply referred to as the "axis direction," the radial direction centered on the central axis J will be simply referred to as the "radial direction," and the circumferential direction centered on the central axis J, that is, around the axis of the central axis J, will be simply referred to as the "circumferential direction." In the radial direction, the side approaching the central axis J will be referred to as the "inside radial direction," and the side moving away from the central axis J will be referred to as the "outside radial direction." In the circumferential direction, the clockwise side when looking from the -Y side to the +Y side will be referred to as the "one side circumferential," and the counterclockwise side will be referred to as the "other side circumferential."

[0015] In this specification, "extending in the axial direction" includes not only cases where the material extends strictly in the axial direction, but also cases where the material extends in a direction inclined to the axial direction by an angle of less than 45°. Furthermore, in this specification, "extending radially" includes not only cases where the material extends strictly radially, i.e., perpendicular to the axial direction, but also cases where the material extends in a direction inclined to the radial direction by an angle of less than 45°. Furthermore, "parallel" includes not only cases where the material is strictly parallel, but also cases where the angle between the material and the material is inclined to each other by an angle of less than 45°. Furthermore, "spreading in a direction perpendicular to the axial direction" includes not only cases where the material spreads in a direction perpendicular to the axial direction, but also cases where the material spreads in a direction inclined to the direction perpendicular to the axial direction by an angle of less than 45°.

[0016] The motor 10 includes a stator 200, a rotor 300 positioned opposite the stator 200 radially inward with an air gap in between, and a shaft 400 fixed radially inward of the rotor 300 and extending along a central axis J. The stator 200 includes a stator core 210, a first coil end 230 projecting axially in one direction at one axial end of the stator core 210, and a second coil end 220 projecting axially in the other direction at the other axial end of the stator core 210.

[0017] Further, the motor 10 has a motor frame 100 that covers the stator 200 from the radially outer side. By covering the stator 200 from the radially outer side, the motor frame 100 houses 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 refrigerant toward the stator 200, and a refrigerant tank 600 that temporarily stores the refrigerant and allows it to flow downward in the vertical direction. The refrigerant discharge pipe 510, the refrigerant discharge pipe 520, and the refrigerant tank 600 are provided above the stator 200 in the vertical direction within the stator 200. The refrigerant is, for example, cooling oil. The refrigerant supplied to the stator 200 cools the stator 200. In the present embodiment, the Z direction is the vertical direction, and the refrigerant supplied from the refrigerant discharge pipe 510, the refrigerant discharge pipe 520, and the refrigerant tank 600 to the stator 200 flows to the +Z side and is stored in an oil pan (not shown) provided on the lower side in the vertical direction within the motor frame 100. The refrigerant stored in the oil pan is sucked up by a pump 700, cooled by an oil cooler (not shown), and then circulated and supplied to the refrigerant discharge pipe 510 and the refrigerant discharge pipe 520. The materials of the refrigerant discharge pipe 510 and the refrigerant discharge pipe 520 are, for example, iron or resin.

[0019] FIG. 2 is a plan view showing the upper part of the stator 200 excluding the motor frame 100 from the motor 10. The refrigerant discharge pipe 510 is arranged offset to one side in the circumferential direction from directly above the central axis J, and the refrigerant discharge pipe 520 is arranged 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 the present 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 at least one refrigerant discharge pipe may be provided.

[0020] FIG. 3 is a partial perspective view showing the vicinity of the refrigerant tank 600. The refrigerant tank 600 is located directly above the central axis J and is arranged between the refrigerant discharge pipe 510 and the refrigerant discharge pipe 520 in the circumferential direction. The refrigerant tank 600 has a storage portion 610, a recess portion 620, a through hole 621, a through hole 622, and a through hole 623.

[0021] The storage part 610 is a recess where the refrigerant discharged by the refrigerant discharge pipes 510 and 520 is temporarily stored. The storage part 610 has a constant depth except for the part where the recessed part 620 is formed. The bottom surface of the storage part 610 is orthogonal to the Z-axis direction. The recessed part 620 is a recess elongated in the X-axis direction formed at the bottom of the storage part 610. The recessed part 620 has a constant depth except for the part 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 penetrating the bottom of the recessed part 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 etc. by flowing downward the refrigerant temporarily stored in the storage part 610.

[0022] The refrigerant discharge pipes 510 and 520 are both pipes through which the refrigerant flows inside. The refrigerant discharge pipes 510 and 520 both have holes for discharging the refrigerant for cooling the motor 10 to the storage part 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] FIG. 4 is a diagram showing the refrigerant discharge pipe 510. FIG. 4(A) is a side view of the refrigerant discharge pipe 510 viewed from the -X side. FIG. 4(B) is a side cross-sectional view showing the refrigerant discharge pipe 510 of FIG. 4(A) cut along a plane passing through the pipe axis of the refrigerant discharge pipe 510 extending in the Y-axis direction and orthogonal to the X-axis direction. Since the structure of the refrigerant discharge pipe 520 is the same as the structure of the refrigerant discharge pipe 510, only the refrigerant discharge pipe 510 will be described here.

[0024] The refrigerant discharge pipe 510 has a first piping part 512 for supplying the refrigerant into the refrigerant discharge pipe 510, a second piping part 511 for supplying the refrigerant in the axial direction, and a mounting part 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 the mounting part 513 being mounted on the upper side in the vertical direction within the motor frame 100.

[0025] The first piping section 512 has a supply port 512a for receiving refrigerant from the outside, and a first flow path 512b which is the flow path for the refrigerant supplied from the supply port 512a. The second piping section 511 has a second flow path 511a which is the flow path for supplying refrigerant in one axial direction, and a third flow path 511b which is the flow path for supplying refrigerant in the other axial direction. The second flow path 511a and the third flow path 511b may have the same flow path diameter or may have different flow path diameters. The refrigerant discharge pipe 510 has a connecting section 515 through which the first piping section 512 and the second piping section 511 communicate. In the connecting section 515, the first flow path 512b, the second flow path 511a, and the third flow path 511b communicate.

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

[0027] In this configuration, the refrigerant branches at the communication section 515 of the second piping section 511 into a second flow path 511a toward the first discharge port 511c on one axial side and a third flow path 511b toward the second discharge port 511f on the other axial side. This suppresses the pressure difference between the first discharge port 511c and the second discharge port 511f, allowing the first coil end 230 and the second coil end 220 to be cooled uniformly.

[0028] The first piping section 512 is inclined with respect to the second piping section 511. Here, inclination means that the first piping section 512 and the second piping section 511 are not perpendicular to each other, but rather the first piping section 512 is tilted axially to one side or the other side relative to the second piping section 511. Therefore, compared to the case where 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, if the first piping section 512 and the second piping section 511 are perpendicular to each other, the first piping section 512 will extend radially outward. In order to supply refrigerant from outside the stator 200 in the smallest possible space, the first flow path 512b needs to communicate with a flow path that extends in a direction perpendicular to the radial direction. In this case, with the configuration in which the first piping section 512 and the second piping section 511 are perpendicular to each other, the point of communication between the flow path that supplies refrigerant to the first flow path 512b and the first flow path 512b is perpendicular, which increases the pressure loss. In contrast, by having the first piping section 512 inclined with respect to the second piping section 511, this pressure loss can be suppressed.

[0030] Furthermore, for example, if the length between the communication section 515 and the second discharge port 511b is shorter than the length between the communication section 515 and the first discharge port 511c, the first piping section 512 may be configured to be tilted axially to the other side relative to the second piping section 511. By doing so, 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, thereby suppressing an increase in pressure loss of the refrigerant flow from the communication section 515 to the first discharge port 511c.

[0031] Furthermore, when operating the motor 10 to cool the first coil end 230 and the second coil end 220, it is desirable to fill the inside of the first piping section 512 and the second piping section 511 with refrigerant. By doing so, 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 embodiments described above, and various improvements and design modifications may be made without departing from the spirit of the invention. For example, the motor 10 may be configured without a 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 in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0034] 10…motor 100...Motor frame 200...Stata 300... Rotor 400...shaft 510, 520...refrigerant discharge pipe

Claims

1. A stator 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 is positioned radially inward of the stator and faces the stator via an air gap, At least one refrigerant discharge pipe positioned vertically above the stator, It has, The refrigerant discharge pipe has 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 connecting section that connects the first piping section and the second piping section. The first piping section has a first flow path which is a flow path for refrigerant supplied from the outside, The second piping section includes a second flow path that supplies refrigerant from the first flow path to one axial direction via the connecting section, a third flow path that supplies refrigerant from the first flow path to the other axial direction via the connecting section, 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. The first piping section is inclined with respect to the second piping section. A rotating electric machine characterized by the following features.

2. The insides of the first and second piping sections are filled with refrigerant. The rotating electric machine according to feature 1.

3. The second piping section has a third discharge port between the first discharge port and the second discharge port for discharging refrigerant to the stator coil. The rotating electric machine according to feature 1.

4. 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. The first piping section is tilted axially to the other side relative to the second piping section. The rotating electric machine according to feature 1.

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