motor

Abstract

This technology enhances the cooling effect on the coil ends. [Solution] The motor comprises a motor case, a stator, a coil disposed on the stator, and a flow path forming member that forms a flow path through which a refrigerant flows for cooling the coil end, which is one end of the motor in the axial direction, and is provided in an annular shape along the inner periphery of the motor case, wherein the flow path forming member comprises a first wall portion that faces the coil end over a range of at least a portion of the axial length of the coil end, and has a discharge port for discharging the refrigerant to a first portion spaced apart from the tip of the coil end in the axial direction in the opposite direction to the first portion, and a second wall portion that extends along the radial direction of the motor toward a second portion which is a portion of the coil end that is more proximal to the tip in the axial direction than the first portion.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a motor.

[0002] Vehicle drive devices such as e-axles include a motor case and a motor disposed within the motor case. A coil is disposed in the stator core of the motor, and the coil protrudes from the end face of the stator core to form a coil end. For example, the refrigerant introduced from the outside of the motor case may be introduced into an annular refrigerant flow path provided in a ring shape or the like along the outer periphery of the coil end. It is disclosed that the refrigerant is circulated axially from the end of the stator core through the inside of the stator core via such a refrigerant flow path to cool the stator core (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The refrigerant discharged from such a refrigerant flow path can also be discharged toward the coil end. However, the refrigerant discharged toward the coil end may hit the coil end and scatter beyond the outer side in the radial direction of the motor or the tip of the coil end. The scattered refrigerant flows downward in the gravitational direction without reaching the coil end again and is discharged outside the motor case. Therefore, depending on the amount of the scattered refrigerant, it is conceivable that the cooling effect on the coil end cannot be sufficiently obtained.

[0005] This specification provides a technique for enhancing the cooling effect on the coil end.

[0006] The motor disclosed herein comprises a motor case, a stator, a coil disposed on the stator, and a flow path forming member that forms a flow path through which a coolant flows for cooling the coil end, which is one end of the motor in the axial direction, and is provided in an annular shape along the inner periphery of the motor case. The flow path forming member comprises a first wall portion facing the coil end over a range of at least a portion of the axial length of the coil end, and a second wall portion extending radially toward the coil end of the motor.

[0007] The first wall portion has a discharge port for discharging the refrigerant to a first portion spaced apart from the tip of the coil end in the axial direction opposite to the first portion, and the second wall portion extends toward a second portion which is more proximal to the tip in the axial direction than the first portion.

[0008] According to the above configuration, refrigerant is discharged from the discharge port of the refrigerant forming member toward the coil end. The discharged refrigerant strikes the coil end and scatters radially outward and toward one side in the axial direction of the motor.

[0009] When the refrigerant discharged toward the coil end is scattered radially outward from the motor, it mainly hits the first wall. When the refrigerant hits the first wall, it again adheres to the portion of the coil end facing the first wall, cooling that portion. On the other hand, when the refrigerant is scattered to one side in the axial direction, it hits the second wall. The second wall extends radially toward the coil end at a second portion that is proximal to the tip in the axial direction than the first portion where the discharge port is formed. Therefore, when the refrigerant hits the second wall, it travels along the second wall and again adheres to the portion of the coil end that the second wall points to, cooling that portion.

[0010] From the above, even if the refrigerant discharged toward the coil end is scattered, the refrigerant will again adhere to the area including the first part of the coil end, as well as to the second part, which is the tip or its vicinity, thereby cooling these parts. As a result, the cooling effect on the coil end is improved.

[0011] In this configuration, when the coil end has an outer circumference that protrudes radially outward at the first portion and an outer circumference that is retracted radially inward at the second portion, the cooling effect on the coil end is further improved. [Brief explanation of the drawing]

[0012] [Figure 1] A cross-sectional view of the motor. [Figure 2] Enlarged cross-sectional view of the refrigerant flow path and its surroundings. [Figure 3] An explanatory diagram regarding the discharge and re-adhesion of refrigerant to the coil end. [Modes for carrying out the invention]

[0013] The motors disclosed herein will be described below with reference to the drawings as appropriate. These motors can be used as part of a vehicle drive system.

[0014] As shown in Figure 1, the motor 10 has a rotor 20, a stator 30, and a motor case (hereinafter simply referred to as the case) 50. The rotor 20 has a shaft 24. The stator 30 has a cylindrical shape. The rotor 20 is positioned within the central hole of the stator 30 such that the central axis of the shaft 24 coincides with the central axis of the stator 30. The rotor 20 and the stator 30 are housed in the case 50. Hereafter, the direction parallel to the rotation axis of the motor 10 (i.e., the central axis of the shaft 24) will be referred to as the axial direction, and the direction along the radius of the circle centered on the rotation axis of the motor 10 will be referred to as the radial direction.

[0015] The case 50 has a so-called bottomed cylindrical shape and has an outer circumferential wall 52 and a partition wall 54. The outer circumferential wall 52 has a cylindrical shape. The partition wall 54 is provided at one end of the outer circumferential wall 52 in the axial direction X (hereinafter referred to as the X direction). A through hole 54a is provided at the center of the partition wall 54.

[0016] The stator 30 has a stator core 32 and a coil 40. In Figure 1, the coil 40 is shown in a simplified form. The stator core 32 has a cylindrical shape. The coil 40 is wound around the stator core 32. The stator core 32 has end faces 32a and 32b. End face 32a is the end face of the stator core 32 in the X direction, and end face 32b is the end face in the other direction Y (hereinafter referred to as the Y direction), which is the opposite direction in the axial direction from end face 32a. A coil end 42a is provided on end face 32a. A coil end 42b is provided on end face 32b. The coil ends 42a and 42b are the bent portions of the coil 40 wound around the stator core 32. The coil end 42a protrudes from end face 32a and has a tip portion 43 at its tip in the X direction. The coil end 42b also protrudes from end face 32b. The coil ends 42a and 42b are distributed in an annular shape on the end faces 32a and 32b, respectively. As shown in Figure 2, the stator core 32 is fastened and fixed to the case 50 by bolts or the like, with the outer peripheral edge of the end face 32a in contact with a stepped portion 59 that protrudes radially inward from the outer peripheral wall 52 of the case 50.

[0017] The shape of the coil end 42a is not particularly limited. The outer periphery 46 of the coil end 42a may have an uneven shape in the radial direction. For example, as shown in an enlarged view in Figure 2, the coil end 42a has an outer periphery 46a that protrudes radially outward at a predetermined distance from the tip 43 in the Y direction, and an outer periphery 46b that is receding radially inward at a portion proximal to the tip 43 than the outer periphery 46a in the axial direction. The outer periphery 46b is formed in a range that extends all the way to the tip 43. When the outer periphery 46 of the coil end 42a has such an uneven shape, the flow path forming member 60 may be even more meaningful.

[0018] As shown in Figure 1, the rotor 20 is positioned concentrically with the stator core 32 and within the central hole of the stator core 32. The shaft 24 of the rotor 20 is inserted through the through hole 54a of the case 50. The rotor 20 is rotatably supported within the case 50 by bearings or the like.

[0019] As shown in Figures 1 and 2, the motor 10 has a flow path forming member 60. The flow path forming member 60 has a ring shape. As shown in Figure 2, the outer diameter of the flow path forming member 60 (i.e., the diameter at the largest diameter portion) is smaller than the diameter of the outer circumferential surface of the stator core 32. The inner diameter of the flow path forming member 60 (i.e., the diameter at the smallest diameter portion) is larger than the outer diameter of the coil end 42a.

[0020] As shown in Figures 1 and 2, the flow path forming member 60 is housed within the case 50. The flow path forming member 60 is arranged to extend in an annular shape around the axis of the motor 10 (i.e., the shaft 24). The flow path forming member 60 is positioned concentrically with the rotor 20 and the stator core 32, between the end face 32a of the stator core 32 and the partition wall 54 of the case 50.

[0021] As shown in Figure 2, the flow path forming member 60 is fixed by being sandwiched between the end face 32a and the partition wall 54. The coil end 42a is positioned radially inward of the flow path forming member 60. The flow path forming member 60 divides the space between the stator core 32 and the partition wall 54 into an outer circumferential space 56 and an inner circumferential space 57. The outer circumferential space 56 is the space enclosed by the inner surface of the case 50, the outer circumferential surface of the flow path forming member 60, and the end face 32a, forming an annular refrigerant flow path.

[0022] The flow path forming member 60 is provided with a wall portion 60a that faces the coil end 42a from its outer circumference. The wall portion 60a is formed over approximately the entire length that protrudes along the axial direction of the coil end 42a. The wall portion 60a is an example of a first wall portion.

[0023] The wall portion 60a is provided with a plurality of discharge ports 62 along the circumferential direction. As shown in FIG. 2, each discharge port 62 is formed at a portion A which is separated from the tip portion 43 by a predetermined distance in the Y direction at the coil end 42a. At the same time, each discharge port 62 is formed so as to face the outer peripheral portion 46a of the coil end 42a. The portion A is an example of the first portion.

[0024] The discharge port 62 penetrates the wall portion 60a in the radial direction. As shown in FIG. 2, the refrigerant flow path 56 and the space 57 (that is, the space where the coil end 42a exists) are connected by the discharge port 62. Each discharge port 62 discharges the refrigerant in the refrigerant flow path 56 from the outside in the radial direction with respect to the outer peripheral portion 46a of the coil end 42a.

[0025] The flow path forming member 60 includes a wall portion 60b between the partition wall 54. The wall portion 60b extends along the radial direction toward the tip portion 43 of the coil end 42a. That is, the wall portion 60b is a portion B which is the most proximal portion with respect to the tip portion 43 rather than the portion A in the coil end 42a, that is, extends toward the tip portion 43. Further, the wall portion 60b is formed in an annular shape on the partition wall 54 side of the flow path forming member 60. The wall portion 60b is an example of the second wall portion. The portion B is an example of the second portion.

[0026] The extending width toward the inside in the radial direction of the wall portion 60b can be set as appropriate. For example, it is made to extend to a position where the refrigerant hitting the outer peripheral portion 46a of the coil end 42a scatters and adheres.

[0027] In addition, each connection portion between the flow path forming member 60 and the end face 32a and between the flow path forming member 60 and the partition wall 54 is appropriately sealed with a sealing member (O-ring, metal gasket, liquid gasket, etc.).

[0028] As shown in Figures 1 and 2, the case 50 is provided with a refrigerant supply passage 53a. The refrigerant supply passage 53a connects the outside of the case 50 to the refrigerant flow path 56. As shown in Figure 1, a refrigerant discharge passage 53b is provided at the bottom of the case 50. The refrigerant discharge passage 53b connects the inside and outside of the case 50. The refrigerant discharge passage 53b is connected to the refrigerant supply passage 53a via a circulation passage (not shown) located outside the case 50. A pump (not shown) is provided in the circulation passage. When the pump operates, refrigerant is supplied from the refrigerant supply passage 53a to the refrigerant flow path 56. The refrigerant supplied to the refrigerant flow path 56 flows through the inside of the case 50 and is discharged from the refrigerant discharge passage 53b to the circulation passage outside the case 50. The refrigerant is, for example, cooling oil. The cooling oil functions as a coolant to cool the motor 10 and as a lubricant to lubricate the rotor 20.

[0029] As shown in Figures 1 and 2, the stator core 32 is provided with an internal refrigerant passage 39 that communicates with a refrigerant passage 56. The internal refrigerant passage 39 opens at end faces 32a and 32b, respectively, and is configured to cool the stator core 32 with refrigerant supplied through the refrigerant passage 56. The refrigerant discharged from end face 32b is discharged to the outside of the case 50 through a refrigerant discharge passage 53b.

[0030] Next, the cooling effect of the refrigerant on the coil end 42a during the operation of the motor 10 will be explained with reference to Figure 3. When the motor 10 is in operation, refrigerant is supplied to the inside of the case 50. The refrigerant is supplied from the refrigerant supply passage 53a to the refrigerant flow path 56. The refrigerant flows through the refrigerant flow path 39 inside the core and is also discharged from the discharge port 62 toward the outer circumference 46a of the coil end 42a.

[0031] The discharged solvent adheres to the outer periphery 46a of the coil end 42a, while a portion of it scatters and hits the wall portions 60a and 60b again, then adheres to the outer periphery 46a and 46b, cooling the coil end 42a. In this embodiment, since the solvent is discharged to the outer periphery 46a that is closest to the discharge port 62, the refrigerant can be reliably attached to the outer periphery 46a for effective cooling. Furthermore, by discharging the solvent to the outer periphery 46a that is closest, the solvent can be reliably scattered in the X direction and adhere to the wall portion 60b. As a result, the refrigerant that adheres to the wall portion 60b and flows down is reliably attached to the outer periphery 46b, effectively cooling the outer periphery 46b.

[0032] Furthermore, according to this embodiment, since the discharge port 62 protrudes most radially outward and faces the outer peripheral portion 46a that is close to the discharge port 62, even if only a single discharge port 62 is provided in the axial direction, the coil end 42a can be cooled over almost the entire axial direction.

[0033] The shape of the flow path forming member 60 is not particularly limited, and it is sufficient if it can form an annular refrigerant flow path near the outer edge of the stator core 32. The shape of the outer periphery 46 of the coil end 42a can also be changed as appropriate. [Explanation of symbols]

[0034] 10: Motor, 30: Stator, 32: Stator core, 39: Coolant flow path inside core, 42a: Coil end, 50: Case, 52: Outer wall, 54: Partition wall, 56: Coolant flow path, 60: Flow path forming member

Claims

[Claim 1] It is a motor, Motor case and stator and, The coils arranged in the stator, A flow path forming member that forms a flow path through which a coolant flows for cooling the coil end, which is one end of the motor in the axial direction, and which is provided in an annular shape along the inner periphery of the motor case, Equipped with, The flow path forming member comprises a first wall portion facing the coil end over a range of at least a portion of the axial length of the coil end, and a second wall portion extending toward the coil end along the radial direction of the motor, The first wall portion has a discharge port for discharging the refrigerant to a first portion spaced apart from the tip of the coil end in the axial direction opposite to the one mentioned above. A motor wherein the second wall portion extends toward a second portion that is more proximal to the tip portion in the axial direction than the first portion.

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