motor

Abstract

Efficiently cools the coil ends. [Solution] A motor comprising: a stator core; a case housing the stator core; a guide ring housed within the case, having a ring shape extending around the motor shaft and in contact with the end face of the stator core; an annular coolant flow channel provided between the inner circumferential surface of the case and the outer circumferential surface of the guide ring; and a coil wound around the stator core, the coil having a coil end positioned on the inner circumferential side of the guide ring. The guide ring has a discharge port for discharging coolant from the annular coolant flow channel toward the coil end, the discharge port discharging coolant in a direction inclined in the circumferential direction of the coil end with respect to the radial direction of the coil end.

Description

Technical Field

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

[0002] The motor disclosed in Patent Document 1 cools the coil end by discharging a coolant from above the coil end of the stator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When discharging a coolant to the coil end as in Patent Document 1, the flow rate of the coolant decreases on the surface of the coil end, and the coil end cannot be efficiently cooled. In this specification, a technique for efficiently cooling the coil end is proposed.

Means for Solving the Problems

[0005] The motor disclosed in this specification includes a stator core, a case that houses the stator core, a guide ring that is housed in the case, has a ring shape extending around the motor shaft, and contacts an end face of the stator core, an annular coolant flow path provided between an inner peripheral surface of the case and an outer peripheral surface of the guide ring, and a coil wound around the stator core and having a coil end disposed on an inner peripheral side of the guide ring. The guide ring has a discharge port that discharges the coolant in the annular coolant flow path toward the coil end, and the discharge port discharges the coolant along a direction inclined in a circumferential direction of the coil end with respect to a radial direction of the coil end.

[0006] In this motor, the discharge port provided in the guide ring discharges the coolant along a direction inclined in the circumferential direction of the coil end relative to the radial direction of the coil end. Therefore, the coolant flows easily along the circumferential direction on the surface of the coil end, and the decrease in the flow velocity of the coolant on the surface of the coil end can be suppressed. As a result, the coil end can be cooled efficiently. [Brief explanation of the drawing]

[0007] [Figure 1] Exploded perspective view of the motor in the embodiment. [Figure 2] A partial cross-sectional view of the motor in the embodiment. [Figure 3] A plan view of the stator along the axial direction. [Modes for carrying out the invention]

[0008] The motor 10 in the embodiment shown in Figures 1 and 2 has a rotor 20, a stator 30, and a 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 stator 30 are housed in the case 50. Hereinafter, 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.

[0009] 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 is cylindrical in shape. The partition wall 54 is provided at one end of the outer circumferential wall 52 in the axial direction. A through hole 54a is provided at the center of the partition wall 54.

[0010] The stator 30 has a stator core 32 and a coil 40. The stator core 32 has a cylindrical shape. Although not shown, the inner circumferential surface of the stator core 32 is provided with a plurality of teeth that project toward the central axis of the stator core 32. The coil 40 is wound around each tooth. The stator core 32 has end faces 32a and 32b. End face 32a is one axial end face of the stator core 32, and end face 32b is the end face opposite to 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 the coil end 42b protrudes from end face 32b. As shown in Figure 3(a), the coil ends 42a are distributed in an annular pattern on the end face 32a. Similarly, the coil ends 42b are distributed in an annular pattern on the end face 32b. As shown in Figures 1 and 2, the stator core 32 is housed within the case 50. The stator core 32 is fastened to the case 50 by bolts 49.

[0011] As shown in Figures 1 and 2, the outer peripheral wall 52 of the case 50 has a cylindrical shape that extends along the outer peripheral surface of the stator core 32. The outer peripheral wall 52 faces the outer peripheral surface of the stator core 32. The partition wall 54 of the case 50 faces the end face 32a of the stator core 32. As shown in Figure 2, a gap is provided between the partition wall 54 and the end face 32a of the stator core 32, and the coil end 42a is positioned within this gap.

[0012] 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.

[0013] As shown in Figures 1 and 2, the motor 10 has a guide ring 60. The guide ring 60 has a ring shape. The outer diameter of the guide ring 60 (i.e., the diameter at its largest diameter) is smaller than the diameter of the stator core 32. The inner diameter of the guide ring 60 (i.e., the diameter at its smallest diameter) is larger than the outer diameter of the coil end 42a. The guide ring 60 is housed within the case 50. The guide ring 60 is arranged to extend in an annular shape around the axis of the motor 10 (i.e., the shaft 24). The guide ring 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. The guide ring 60 is sandwiched and fixed between the end face 32a and the partition wall 54. The coil end 42a is positioned radially inward of the guide ring 60. The guide ring 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 a space enclosed by the inner circumferential surface of the outer circumferential wall 52, the outer circumferential surface of the guide ring 60, the partition wall 54, and the end face 32a of the stator core 32, and has an annular shape. Hereinafter, the outer circumferential space 56 will be referred to as the annular coolant flow path 56.

[0014] As shown in Figure 2, the case 50 is provided with a coolant supply passage 53a. The coolant supply passage 53a connects the outside of the case 50 to the annular coolant flow path 56. A coolant discharge passage 53b is provided at the bottom of the case 50. The coolant discharge passage 53b connects the inside and outside of the case 50. The coolant discharge passage 53b is connected to the coolant supply passage 53a via a circulation passage (not shown) provided outside the case 50. A pump (not shown) is provided in the circulation passage. When the pump operates, coolant is supplied from the coolant supply passage 53a to the annular coolant flow path 56. The coolant supplied to the annular coolant flow path 56 flows inside the case 50 and is discharged from the coolant discharge passage 53b to the circulation passage outside the case 50. In this way, the coolant circulates between the circulation passage and the case 50. In this embodiment, the coolant is cooling oil. The cooling oil functions as a coolant to cool the motor 10, and also as a lubricant to lubricate the rotor 20.

[0015] As shown in Figure 2, multiple internal coolant flow channels 39 are formed within the stator core 32. The upstream end of each internal coolant flow channel 39 is connected to an annular coolant flow channel 56. The downstream end of each internal coolant flow channel 39 opens to the end face 32b. Multiple internal coolant flow channels 39 are provided inside the stator core 32, distributed circumferentially.

[0016] As shown in Figure 3(a), the inner circumferential surface of the guide ring 60 is provided with a plurality of protrusions. Each portion with a protrusion is a thickened portion 62 that is thicker than the rest of the guide ring 60. The guide ring 60 has a plurality of thickened portions 62 distributed in the circumferential direction. Each thickened portion 62 is provided with a discharge port 64. Each discharge port 64 penetrates the guide ring 60. The discharge ports 64 connect the annular coolant flow path 56 to the space 57 (i.e., the space where the coil end 42a exists). Each discharge port 64 discharges the coolant in the annular coolant flow path 56 toward the coil end 42a. Each discharge port 64b, except for the uppermost discharge port 64a, extends so as to be inclined along the circumferential direction with respect to the radial direction of the coil end 42a. Each discharge port 64b discharges the coolant diagonally downward along the circumferential direction toward the coil end 42a. More specifically, each discharge port 64b discharges the coolant along the tangential direction of the coil end 42a.

[0017] When the motor 10 is operating, coolant is supplied to the inside of the case 50. The coolant is supplied from the coolant supply passage 53a to the annular coolant passage 56. The coolant in the annular coolant passage 56 flows to the core coolant passage 39 and the discharge port 64. The stator core 32 is cooled by the coolant flowing in the core coolant passage 39. The coolant that has flowed through the core coolant passage 39 to the downstream end is discharged from the end face 32b. The coil end 42b is cooled by the coolant discharged from the end face 32b. In addition, the coolant that has flowed into the discharge port 64 is discharged toward the coil end 42a. This cools the coil end 42a. The coolant discharged from the core coolant passage 39 and the discharge port 64 flows toward the bottom of the case 50. The coolant that has flowed toward the bottom of the case 50 is sent from the coolant discharge passage 53b to the coolant supply passage 53a via an external pump. In this way, the motor 10 is cooled by the circulation of the coolant.

[0018] As described above, each outlet 64b discharges coolant diagonally downward along the circumferential direction relative to the coil end 42a. That is, each outlet 64b discharges coolant along the tangential direction of the coil end 42a. Therefore, the flow velocity of the coolant does not decrease easily at each point where the coolant discharged from the outlet 64b hits the coil end 42a. Consequently, the coolant discharged from the outlet 64b flows circumferentially at a relatively fast speed at the coil end 42a, and the coolant does not easily stagnate on the surface of the coil end 42a. As a result, the coil end 42a is cooled efficiently. As explained above, the inclination of the outlet 64b with respect to the radial direction improves the cooling efficiency of the coil end 42a.

[0019] In Figure 3(a), the thickened portion 62 was formed by providing a protrusion on the inner circumferential surface of the guide ring 60, but as shown in Figure 3(b), the thickened portion 62 may also be formed by providing a protrusion on the outer circumferential surface of the guide ring 60. In this configuration as well, each thickened portion 62 can be provided with a discharge port 64b that is inclined along the radial direction.

[0020] Although embodiments have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness. [Explanation of Symbols]

[0021] 10: Motor, 30: Stator, 32: Stator core, 42a: Coil end, 50: Case, 52: Outer wall, 54: Partition, 56: Annular coolant flow path, 60: Guide ring, 62: Outlet

Claims

[Claim 1] It is a motor, Stator core and The case housing the stator core, Housed within the aforementioned case, it has a ring shape extending around the motor shaft, and includes a guide ring that contacts the end face of the stator core, An annular coolant flow path is provided between the inner circumferential surface of the case and the outer circumferential surface of the guide ring, A coil wound around the stator core, the coil having a coil end positioned on the inner circumference side of the guide ring, It has, The guide ring has a discharge port for discharging the coolant in the annular coolant flow path toward the coil end, and the discharge port has a direction inclined toward the circumferential direction of the coil end with respect to the radial direction of the coil end. Motor.

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