Motor

Abstract

To easily and properly arrange a guide ring in a case of a motor.SOLUTION: A motor includes: a stator core; a case having a facing portion facing an end surface of the stator core; and a guide ring having a ring shape extending around a motor shaft and sandwiched between the end surface and the facing portion. An annular coolant flow path is formed by a space surrounded by an inner surface of the case, an outer peripheral surface of the guide ring, and the end surface. A plurality of in-core coolant flow paths are provided inside the stator core. An inflow port of each of the in-core coolant flow paths opens in the end surface at a position outside the guide ring in a radial direction and is connected to the annular coolant flow path.SELECTED DRAWING: Figure 2

Description

Technical Field

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

[0002] The motor disclosed in Patent Document 1 has a case, a stator core, and a guide ring. The stator core and the guide ring are accommodated in a cylindrical case. The guide ring has a base portion that contacts the end face of the stator core and an annular convex portion that extends radially outward from the base portion. A gap is provided between the annular convex portion and the end face of the stator core. The outer peripheral surface of the stator core and the outer peripheral surface of the annular convex portion are in contact with the inner peripheral surface of the case. An annular coolant flow path is formed by the space surrounded by the stator core, the guide ring, and the case. Further, a plurality of coolant flow paths inside the core are provided inside the stator core. The inlet of each coolant flow path inside the core is connected to the annular coolant flow path. When coolant (for example, oil) is supplied from the outside of the case to the annular coolant flow path, the coolant flows from the annular flow path to each coolant flow path inside the core. Thereby, the stator core is cooled from the inside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the motor of Patent Document 1, the outer peripheral surface of the guide ring (i.e., the outer peripheral surface of the annular convex portion) is in contact with the inner peripheral surface of the case. Therefore, if the diameters and roundness of the inner peripheral surface of the case and the outer peripheral surface of the guide ring are not accurate, a gap will occur between the case and the guide ring. When a gap occurs between the case and the guide ring, problems such as a decrease in the shape accuracy of the entire motor and leakage of the coolant in the annular flow path will occur. Further, when the inner peripheral surface of the case and the outer peripheral surface of the guide ring are processed with high precision so that no gap occurs between the case and the guide ring, problems such as an increase in processing cost and difficulty in inserting the guide ring into the case will occur. In this specification, a technique that can easily and appropriately arrange a guide ring in the case of a motor is proposed.

Means for Solving the Problems

[0005] (Configuration 1) The motor of Configuration 1 disclosed in this specification includes a stator core, a case, and a guide ring. The case houses the stator core. The case has an opposing portion that opposes one end surface of the stator core. The guide ring is housed in the case, has a ring shape extending around the motor shaft, and is sandwiched between the end surface and the opposing portion. An annular coolant flow path is formed by the inner surface of the case, the outer peripheral surface of the guide ring, and the space surrounded by the end surface. A plurality of coolant flow paths inside the core are provided inside the stator core. The inlet of each coolant flow path inside the core opens to the end surface at a position radially outside the guide ring and is connected to the annular coolant flow path.

[0006] In this specification, the radial direction means the direction along the radius of a circle centered on the motor shaft.

[0007] In this motor, the guide ring is sandwiched and fixed between the end face of the stator core and the opposing portion of the case in the axial direction (i.e., the direction parallel to the motor axis). By laminating the opposing portion, the guide ring, and the stator core in the axial direction, the guide ring can be easily fixed. Further, by laminating in this way, the gap between the guide ring and the case can be suppressed regardless of the shape accuracy of the guide ring. Thus, according to the structure of this motor, the guide ring can be easily and appropriately arranged within the motor case.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0009] The additional configuration of the motor disclosed in this specification will be described below.

[0010] (Configuration 2) It further has a coil wound around the stator core at a position inside the guide ring in the radial direction. Each coolant flow path in the core is arranged outside the guide ring in the radial direction and includes a first flow path connected to the inlet. extends from a position outside the guide ring to a position inside the guide ring in the radial direction and is a second flow path connected to the first flow path. is arranged inside the guide ring in the radial direction, extends along the axial direction, and is a third flow path connected to the second flow path. It has the motor according to Configuration 1. (Configuration 3) The motor according to Configuration 2, wherein each of the second flow paths extends along the radial direction. (Configuration 4) The stator core is composed of a plurality of electromagnetic steel sheets laminated in the axial direction. A first through hole arranged outside the guide ring in the radial direction is provided in a first electromagnetic steel sheet, which is one or more electromagnetic steel sheets existing in the range including the end face among the plurality of electromagnetic steel sheets. A second through hole extending along the radial direction is provided in a second electromagnetic steel sheet, which is one or more electromagnetic steel sheets adjacent to the first electromagnetic steel sheet among the plurality of electromagnetic steel sheets. A third through hole arranged inside the guide ring in the radial direction is provided in a third electromagnetic steel sheet, which is a plurality of electromagnetic steel sheets adjacent to the second electromagnetic steel sheet among the plurality of electromagnetic steel sheets. The first flow path is formed by the first through hole. The second flow path is formed by the second through hole. The third flow path is formed by the third through hole. The motor according to Configuration 2 or 3. (Configuration 5) The stator core has a back yoke and a plurality of teeth protruding inward in the radial direction from the back yoke. The coil is wound around the plurality of teeth. The third flow path is provided inside the corresponding teeth. The motor according to any one of Configurations 2 to 4. (Configuration 6) The motor according to Configuration 5, wherein the third flow path is provided at a boundary between the back yoke and the corresponding teeth. (Configuration 7) A coil end is provided on the end face. The inner diameter of the guide ring is larger than the outer diameter of the coil end. The motor according to any one of Configurations 1 to 6. (Configuration 8) A coil end is provided inside the guide ring in the radial direction. The guide ring is provided with a coolant discharge flow path penetrating the guide ring in the radial direction. The motor according to any one of Configurations 1 to 7. (Configuration 9) The case has a contact portion that contacts the end face. A seal member is provided at an interface between the end face and the contact portion. The motor according to any one of Configurations 1 to 8. (Configuration 10) The motor according to any one of Configurations 1 to 9, wherein a recess is provided on an inner peripheral surface of the case.

[0011] According to Configurations 2 and 3, the coil can be efficiently cooled.

[0012] According to Configuration 4, a coolant flow path inside the core can be easily formed.

[0013] According to Configurations 5 and 6, the coil can be efficiently cooled.

[0014] According to Configuration 7, a guide ring can be attached to the stator core with a coil provided thereon.

[0015] According to Configuration 8, the coil ends can be efficiently cooled.

[0016] According to Configuration 9, the coolant can be efficiently supplied to the coolant flow path in the core.

[0017] Even if a recess is provided on the inner peripheral surface of the case as in Configuration 10, the guide ring can be appropriately provided.

[0018] The motor 10 of the embodiment shown in FIGS. 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 disposed in 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 accommodated 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) is referred to as the axial direction, and the direction along the radius of the circle centered on the rotation axis of the motor 10 is referred to as the radial direction.

[0019] The case 50 has a so-called bottomed cylindrical shape and has an outer peripheral wall 52 and a partition wall 54. The outer peripheral wall 52 has a cylindrical shape. The partition wall 54 is provided at one end in the axial direction of the outer peripheral wall 52. A through hole 54a is provided at the center of the partition wall 54.

[0020] The stator 30 has a stator core 32 and a coil 40. In FIG. 2, the coil 40 is shown in a simplified manner. The stator core 32 has a cylindrical shape. The coil 40 is wound around the stator core 32 (more specifically, the teeth 34 described later). The stator core 32 has an end face 32a, an end face 32b, and an outer peripheral face 32c. The end face 32a is one end face of the stator core 32 in the axial direction, and the end face 32b is the end face on the opposite side of the end face 32a. A coil end 42a is provided on the end face 32a. The end face 32b is provided with a coil end 42b. The coil ends 42a and 42b are bent portions of the coil 40 wound around the stator core 32. The coil end 42a protrudes from the end face 32a, and the coil end 42b protrudes from the end face 32b. As shown in FIG. 3, the coil ends 42a are distributed annularly on the end face 32a. Similarly, the coil ends 42b are distributed annularly on the end face 32b.

[0021] As shown in FIGS. 1 and 2, the inner surface 52a of the outer peripheral wall 52 of the case 50 has a cylindrical shape extending along the outer peripheral face 32c of the stator core 32. The inner surface 52a of the outer peripheral wall 52 faces the outer peripheral face 32c of the stator core 32. The partition wall 54 of the case 50 faces the end face 32a of the stator core 32. The partition wall 54 is an example of a facing portion. As shown in FIG. 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 disposed within the gap. As shown in FIG. 1, a plurality of convex portions 38 are provided on the outer peripheral face 32c of the stator core 32. Further, a plurality of concave portions 58 are provided on the inner surface 52a of the outer peripheral wall 52. The stator core 32 is accommodated in the case 50 such that each convex portion 38 is disposed within the corresponding concave portion 58. Each convex portion 38 is provided with a bolt fastening hole extending along the axial direction. A bolt 49 is inserted through each bolt fastening hole. The stator core 32 is fastened to the case 50 by the bolt 49.

[0022] The rotor 20 is arranged within the central hole of the stator core 32 in a state concentric with the stator core 32. The shaft 24 of the rotor 20 is inserted into the through-hole 54a of the case 50. The rotor 20 is rotatably supported within the case 50 by bearings or the like.

[0023] As shown in FIGS. 1 and 2, the motor 10 has a guide ring 60. The guide ring 60 has a ring shape. As shown in FIG. 3, the outer diameter of the guide ring 60 (i.e., the diameter at the portion with the largest diameter) is smaller than the diameter of the outer peripheral surface 32c of the stator core 32. The inner diameter of the guide ring 60 (i.e., the diameter at the portion with the smallest diameter) is larger than the outer diameter of the coil end 42a. As shown in FIGS. 1 and 2, the guide ring 60 is housed within the case 50. The guide ring 60 is arranged to extend annularly around the axis of the motor 10 (i.e., the shaft 24). The guide ring 60 is arranged between the end face 32a of the stator core 32 and the partition wall 54 of the case 50 in a state concentric with the rotor 20 and the stator core 32. The guide ring 60 is sandwiched and fixed between the end face 32a and the partition wall 54. The coil end 42a is arranged radially inside the guide ring 60. The guide ring 60 divides the space between the stator core 32 and the partition wall 54 into an outer peripheral side space 56 and an inner peripheral side space 57. The outer peripheral side space 56 is a space surrounded by the inner surface of the case 50, the outer peripheral surface of the guide ring 60, and the end face 32a, and has an annular shape. Hereinafter, the outer peripheral side space 56 will be referred to as the annular coolant flow path 56.

[0024] As shown in FIG. 4, one end of the guide ring 60 is in contact with the end face 32a of the stator core 32. An O-ring 66 is provided at the connection portion between the guide ring 60 and the end face 32a. The O-ring 66 seals the connection portion between the guide ring 60 and the end face 32a. Note that, instead of the O-ring 66, other sealing members (for example, a metal gasket, a liquid gasket, etc.) may be provided. Also, in FIG. 4, the guide ring 60 is in contact with the end face 32a, but a configuration may be adopted in which the guide ring 60 is connected to the end face 32a via a sealing member (that is, the guide ring 60 itself is not in contact with the end face 32a). The other end of the guide ring 60 is in contact with the partition wall 54. An O-ring 68 is provided at the connection portion between the guide ring 60 and the partition wall 54. The O-ring 68 seals the connection portion between the guide ring 60 and the partition wall 54. Note that, instead of the O-ring 68, other sealing members (for example, a metal gasket, a liquid gasket, etc.) may be provided. Also, in FIG. 4, the guide ring 60 is in contact with the partition wall 54, but a configuration may be adopted in which the guide ring 60 is connected to the partition wall 54 via a sealing member (that is, the guide ring 60 itself is not in contact with the partition wall 54).

[0025] A stepped portion 59 is provided on the inner surface 52a of the case 50. The stepped portion 59 is provided over the entire circumferential direction. The end face 32a of the stator core 32 is in contact with the stepped portion 59 in the axial direction. The stepped portion 59 is an example of a contact portion. The end face 32a is in close contact with the stepped portion 59. Note that a sealing member (for example, an O-ring, a metal gasket, a liquid gasket, etc.) may be provided at the interface between the end face 32a and the stepped portion 59.

[0026] The case 50 is provided with a coolant supply passage 53a. The coolant supply passage 53a connects the outside of the case 50 and the annular coolant flow passage 56. As shown in FIG. 2, a coolant discharge passage 53b is provided at the lower part of the case 50. The coolant discharge passage 53b connects the inside and the 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 passage 56. As will be described in detail later, the coolant supplied to the annular coolant flow passage 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 through the circulation passage and the case 50. In this embodiment, the coolant is a cooling oil. The cooling oil functions as a coolant for cooling the motor 10 and also functions as a lubricating oil for lubricating the rotor 20.

[0027] As shown in FIG. 1, the guide ring 60 is provided with a plurality of coolant discharge passages 62. As shown in FIG. 4, each coolant discharge passage 62 penetrates the guide ring 60 in the circumferential direction. As shown in FIG. 1, a plurality of coolant discharge passages 62 are provided in a dispersed manner in the circumferential direction on the guide ring 60. As shown in FIG. 4, the coolant discharge passages 62 connect the annular coolant flow passage 56 and the space 57 (that is, the space where the coil end 42a exists). Each coolant discharge passage 62 discharges the coolant in the annular coolant flow passage 56 toward the coil end 42a.

[0028] FIG. 5 shows an exploded view of the stator core 32. As shown in FIG. 5, the stator core 32 is composed of a plurality of electromagnetic steel sheets 36 laminated in the axial direction. The stator core 32 has a back yoke 33 and a plurality of teeth 34. The back yoke 33 has a cylindrical shape. Each tooth 34 projects from the inner peripheral surface of the back yoke 33. That is, each tooth 34 projects radially inward from the back yoke 33. Each tooth 34 extends along the axial direction. The plurality of teeth 34 are arranged at intervals in the circumferential direction. As described above, the coil 40 is wound around the teeth 34. Each tooth 34 is located radially inward of the guide ring 60. Therefore, as shown in FIG. 3, the coil 40 is arranged radially inward of the guide ring 60.

[0029] The electromagnetic steel sheet 36a shown in FIG. 5 is an electromagnetic steel sheet located at the end in the axial direction among the plurality of electromagnetic steel sheets 36. The electromagnetic steel sheet 36a constitutes the end face 32a of the stator core 32. The electromagnetic steel sheet 36b is adjacent to the electromagnetic steel sheet 36a, and the electromagnetic steel sheet 36c is adjacent to the electromagnetic steel sheet 36b. A plurality of electromagnetic steel sheets 36d are laminated at positions adjacent to the electromagnetic steel sheet 36c. The electromagnetic steel sheets 36a to 36c are thinner than the electromagnetic steel sheet 36d. The electromagnetic steel sheet 36a is provided with a plurality of through holes 37a penetrating the electromagnetic steel sheet 36a in the thickness direction. The plurality of through holes 37a are provided dispersedly in the circumferential direction. As shown in FIG. 4, the through holes 37a are arranged outside the guide ring 60 in the radial direction and are connected to the annular coolant flow path 56. As shown in FIG. 5, the electromagnetic steel sheet 36b is provided with a plurality of through holes 37b penetrating the electromagnetic steel sheet 36b in the thickness direction. Each through hole 37b extends long in the radial direction. The plurality of through holes 37a are provided dispersedly in the circumferential direction at the same interval as the through holes 37a. The electromagnetic steel sheet 36c is provided with a plurality of through holes 37c penetrating the electromagnetic steel sheet 36c in the thickness direction. Each through hole 37c extends long in the radial direction. The plurality of through holes 37c are provided dispersedly in the circumferential direction at the same interval as the through holes 37a. Each electromagnetic steel sheet 36d is provided with a plurality of through holes 37d penetrating the electromagnetic steel sheet 36d in the thickness direction. In each electromagnetic steel sheet 36d, the plurality of through holes 37d are provided dispersedly in the circumferential direction at the same interval as the through holes 37a. As shown in FIG. 4, the through holes 37d are arranged inside the guide ring 60 in the radial direction. As shown in FIGS. 5 and 6, the through holes 37d are provided at the boundary between the back yoke 33 and the teeth 34. That is, the through holes 37d are provided straddling the back yoke 33 and the teeth 34.

[0030] As shown in Fig. 4, by connecting the through holes 37a to 37d to each other, a coolant flow path 39 inside the core is formed in the stator core 32. The through hole 37a constitutes a first flow path (hereinafter referred to as the first flow path 37a) that forms an inlet (i.e., an inlet opening to the end face 32a) disposed outside in the radial direction with respect to the guide ring 60. The through holes 37b and 37c constitute a second flow path (hereinafter referred to as the second flow paths 37b and 37c) that extends from a position outside the guide ring 60 in the radial direction to a position inside. The plurality of through holes 37d constitute a third flow path (hereinafter referred to as the third flow path 37d) that is disposed inside the guide ring 60 in the radial direction and extends along the axial direction. The first flow path 37a and the third flow path 37d are connected by the second flow paths 37b and 37c. The coolant flow path 39 inside the core is formed by the first flow path 37a, the second flow paths 37b, and the third flow path 37d. A plurality of coolant flow paths 39 inside the core are provided dispersedly in the circumferential direction inside the stator core 32. As shown in Fig. 2, the downstream end of each coolant flow path 39 inside the core opens to the end face 32b.

[0031] During the operation of the motor 10, a coolant is supplied into the case 50. The coolant is supplied from the coolant supply passage 53a to the annular coolant flow passage 56. The coolant in the annular coolant flow passage 56 flows into the coolant discharge passage 62 and the coolant flow passage 39 in the core. The coolant flowing in the coolant discharge passage 62 is discharged toward the coil end 42a. Thereby, the coil end 42a is cooled. The coolant discharged toward the coil end 42a flows to the lower part of the case 50. Further, the coolant flowing in the coolant flow passage 39 in the core flows in the third flow passage 37d. The third flow passage 37d is provided inside the tooth 34. Therefore, the coil 40 wound around the tooth 34 is efficiently cooled by the coolant flowing in the third flow passage 37d. In particular, in this embodiment, since the third flow passage 37d is provided at the boundary between the tooth 34 and the back yoke 33, the tooth 34 and the back yoke 33 can be effectively cooled. The coolant flowing to the downstream end in the third flow passage 37d is discharged from the end face 32b. The coil end 42b is cooled by the coolant discharged from the end face 32b. The coolant discharged from the end face 32b flows to the lower part of the case 50. The coolant flowing to the lower part of the case 50 is sent from the coolant discharge passage 53b to the coolant supply passage 53a via an external pump.

[0032] As described above, the motor 10 is cooled by the coolant flowing in the case 50. Since the coolant flow passage 39 in the core extends from an inlet on the outer peripheral side of the guide ring 60 to the third flow passage 37d on the inner peripheral side of the guide ring 60, the coil 40 wound around the stator core 32 on the inner peripheral side of the guide ring 60 can be efficiently cooled.

[0033] Also, in the motor 10, the guide ring 60 is sandwiched between the case 50 and the stator core 32 in the axial direction. According to this configuration, regardless of the shape accuracy of the guide ring 60, the connection portion between the guide ring 60 and the case 50 and the connection portion between the guide ring 60 and the stator core 32 can be tightly connected. Further, by simply laminating the partition wall 54 of the case 50, the guide ring 60, and the stator core 32 in order, the connection portion between the guide ring 60 and the case 50 and the connection portion between the guide ring 60 and the stator core 32 can be pressurized. Therefore, these connection portions can be properly sealed. In particular, when a sealing member is disposed at these connection portions, pressure is appropriately applied to the sealing member, so that these connection portions can be properly sealed. Thereby, leakage of the coolant at each connection portion can be prevented, and the flow rate of the coolant in each flow path can be accurately controlled. Also, in the motor 10, the stator core 32 is in contact with the stepped portion 59 of the case 50 in the axial direction. Therefore, appropriate pressure can also be applied to the connection portion between the stator core 32 and the stepped portion 59, and this connection portion can be properly sealed. Note that, by disposing a sealing member at the connection portion between the stator core 32 and the stepped portion 59, the sealing performance of this connection portion can be further enhanced. By enhancing the sealing performance of the connection portion between the stator core 32 and the stepped portion 59, leakage of the coolant at this connection portion can be prevented, and the flow rate of the coolant in each flow path can be more accurately controlled. Note that even if the coolant flows to the outer peripheral surface 32c of the stator core 32 through the connection portion between the stator core 32 and the stepped portion 59, no particular problem occurs. Therefore, when it is not necessary to control the flow rate of the coolant in each flow path so accurately, the sealing performance of the connection portion between the stator core 32 and the stepped portion 59 may be low.

[0034] Further, in the motor 10, a recess 58 exists on the inner surface 52a of the case 50. In the technique of connecting and sealing the outer peripheral surface of the guide ring and the inner peripheral surface of the case as in Patent Document 1, appropriate sealing performance cannot be obtained when a recess exists on the inner peripheral surface of the case. That is, leakage of the coolant occurs in the recess. In contrast, in the present embodiment, since the guide ring 60 and the case 50 are connected in the axial direction, even if the recess 58 exists on the inner surface 52a of the case 50, the connection portion between the guide ring 60 and the case 50 can be appropriately sealed.

[0035] Further, in the motor 10, the inner diameter of the guide ring 60 is larger than the outer diameter of the coil end 42a. Therefore, after winding the coil 40 around the stator core 32 to complete the stator 30, the guide ring 60 can be attached to the stator core 32. That is, the step of winding the coil 40 around the stator core 32 can be carried out in a state where the guide ring 60 does not exist. Therefore, the stator 30 can be efficiently manufactured.

[0036] In the above-described embodiment, the third flow path 37d was provided at the boundary between the teeth 34 and the back yoke 33. However, as shown in FIG. 7, the entire third flow path 37d may be provided within the teeth 34. Further, as shown in FIG. 8, the entire third flow path 37d may be provided within the back yoke 33. Further, as shown in FIG. 9, a plurality of coolant flow paths 39 within the core may be densely provided at the outermost peripheral portion of the back yoke 33.

[0037] Further, in the above-described embodiment, the inlet (that is, the through hole 37a) was independent for each coolant flow path 39 within the core, but as shown in FIG. 10, the through hole 37a may be provided so as to straddle a plurality of coolant flow paths 39 within the core.

[0038] Also, in FIGS. 6 to 8, one coolant flow path 39 in the core was provided for one tooth 34, but the number of coolant flow paths 39 in the core may be less than that of the teeth 34. For example, as shown in FIG. 11, one coolant flow path 39 in the core may be provided for two teeth 34. By reducing the number of coolant flow paths 39 in this way, the pressure loss in the coolant flow path can be reduced.

[0039] Also, in the above-described embodiment, the coolant discharge flow path 62 was provided in the guide ring 60. However, the coolant discharge flow path 62 may not be provided in the guide ring 60. In this case, by enhancing the sealing performance of the connection portion between the guide ring 60 and the partition wall 54 and the connection portion between the guide ring 60 and the end face 32a, the coolant can be efficiently flowed through the annular coolant flow path 56.

[0040] Also, in the above-described embodiment, the stator core 32 was fixed to the case 50 by bolts 49. However, the stator 30 may be fixed to the case 50 by shrink fitting. In shrink fitting, the stator 30 is arranged in the case 50 in a state where the case 50 is heated, and then the case 50 is cooled and contracted. Then, the inner surface 52a of the case 50 is in close contact with the outer peripheral surface 32c of the stator core 32, and the stator 30 is fixed to the case 50. In this case, the recess 58 and the protrusion 38 can be eliminated from the inner surface 52a of the case 50 and the outer peripheral surface 32c of the stator core 32. Thus, even when the stator 30 is fixed to the case 50 by shrink fitting, the annular coolant flow path 56 can be easily formed by arranging the guide ring 60 so as to be sandwiched between the partition wall 54 and the end face 32a.

[0041] Also, in the above-described embodiment, the partition wall 54 and the outer peripheral wall 52 were integrated, but the partition wall 54 may be constituted separately from the outer peripheral wall 52, and the partition wall 54 may be fixed to the outer peripheral wall 52 by bolts or the like.

[0042] In the above-described embodiments, the first flow path is constituted by a single electromagnetic steel plate 36a. However, the first flow path may be constituted by a plurality of laminated electromagnetic steel plates. Also, in the above-described embodiments, the second flow path is constituted by a plurality of laminated electromagnetic steel plates 36b and 36c. The second flow path may be constituted by a single electromagnetic steel plate.

[0043] In the above-described embodiments, a sealing member is provided at the connection portion between the guide ring 60 and the end face 32a, and at the connection portion between the guide ring 60 and the partition wall 54. However, the sealing member may not be provided. For example, by configuring the guide ring 60 with a highly flexible resin, high sealing performance may be achieved without a sealing member. Also, in order to increase the strength of the guide ring 60, the guide ring 60 may be constituted by metal. Also, a groove may be provided in the partition wall 54, and the guide ring 60 may be in contact with the partition wall 54 within the groove. Also, in FIG. 4, the diameter of the guide ring 60 increases as it approaches the partition wall 54. However, the diameter of the guide ring 60 may decrease as it approaches the partition wall 54, or the diameter of the guide ring 60 may be constant regardless of the axial position.

[0044] In the embodiments, as shown in FIG. 2, the downstream portion of each coolant flow path 39 in the core extends linearly. However, the downstream portion may be shifted radially outward in a stepped manner similar to the upstream portion (i.e., FIG. 4). Thereby, coolant can be efficiently supplied to the coil end 42b.

[0045] The embodiments have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Also, the technology illustrated in this specification or the drawings achieves a plurality of purposes simultaneously, and has technical utility by achieving one of those purposes itself.

Explanation of Reference Numerals

[0046] 10: Motor, 30: Stator, 32: Stator core, 39: Cooling liquid flow path within the core, 42a: Coil end, 50: Case, 52: Outer peripheral wall, 54: Partition wall, 56: Annular cooling liquid flow path, 60: Guide ring, 62: Cooling liquid discharge flow path

Claims

1. A motor, comprising: a stator core; a case housing the stator core, the case having a facing portion facing one end face of the stator core; a guide ring housed in the case, having a ring shape extending around a motor shaft, and sandwiched between the end face and the facing portion; wherein an annular coolant flow path is formed by an inner surface of the case, an outer peripheral surface of the guide ring, and a space surrounded by the end face; a plurality of coolant flow paths inside the stator core are provided; an inlet of each coolant flow path inside the core opens to the end face at a position radially outside the guide ring and is connected to the annular coolant flow path; a motor.

2. further comprising a coil wound around the stator core at a position radially inside the guide ring; each coolant flow path inside the core comprises a first flow path disposed radially outside the guide ring and connected to the inlet; a second flow path extending from a position radially outside the guide ring to a position radially inside the guide ring and connected to the first flow path; a third flow path disposed radially inside the guide ring and extending along an axial direction and connected to the second flow path; wherein the motor according to Claim 1.

3. the motor according to Claim 2, wherein each second flow path extends along the radial direction.

4. the stator core is composed of a plurality of electromagnetic steel sheets laminated in the axial direction; a first through hole disposed radially outside the guide ring is provided in a first electromagnetic steel sheet, which is one or more electromagnetic steel sheets existing in a range including the end face among the plurality of electromagnetic steel sheets; a second through hole extending along the radial direction is provided in a second electromagnetic steel sheet, which is one or more electromagnetic steel sheets adjacent to the first electromagnetic steel sheet among the plurality of electromagnetic steel sheets; a third through hole disposed radially inside the guide ring is provided in a third electromagnetic steel sheet, which is a plurality of electromagnetic steel sheets adjacent to the second electromagnetic steel sheet among the plurality of electromagnetic steel sheets; the first flow path is formed by the first through hole; the second flow path is formed by the second through hole; the third flow path is formed by the third through hole. The motor according to claim 2 or 3.

5. The stator core has a back yoke and a plurality of teeth protruding inward in the radial direction from the back yoke, The coil is wound around the plurality of teeth, The third flow path is provided inside the corresponding tooth, The motor according to claim 2 or 3.

6. The motor according to claim 5, wherein the third flow path is provided at a boundary between the back yoke and the corresponding tooth.

7. A coil end is provided on the end face, The inner diameter of the guide ring is larger than the outer diameter of the coil end, The motor according to any one of claims 1 to 3.

8. A coil end is provided inside the guide ring in the radial direction, The guide ring is provided with a coolant discharge flow path penetrating the guide ring in the radial direction, The motor according to any one of claims 1 to 3.

9. The case has a contact portion that contacts the end face, A seal member is provided at an interface between the end face and the contact portion, The motor according to any one of claims 1 to 3.

10. The motor according to any one of claims 1 to 3, wherein a recess is provided on an inner peripheral surface of the case.

Images