Motor

Abstract

To suppress leakage of a coolant in an annular coolant passage.SOLUTION: A motor comprises a stator core, a case in which the stator core is accommodated, a guide ring, and a seal member. The case includes an opposed part which is opposed to one end face of the stator core. The guide ring has a ring shape extending around a motor shaft and is held between the end face and the opposed part. The seal member is disposed on a target interface that is at least one of an interface between the guide ring and the end face and an interface between the guide ring and the opposed part. An annular coolant passage consists of a space enclosed by an inner surface of the case, an outer peripheral surface of the guide ring, and the end face. The seal member consists of a linear member. The linear member is held by the target interface while being bent in an annular shape along the guide ring in such a manner that both ends are brought into contact with each other.SELECTED DRAWING: Figure 5

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 guide ring are housed in a cylindrical case. The guide ring has a base that contacts the end face of the stator core and an annular protrusion that extends radially outward from the base. The outer circumferential surface of the stator core and the outer circumferential surface of the annular protrusion contact the inner circumferential surface of the case. The space surrounded by the stator core, the guide ring, and the case forms an annular coolant flow path. Coolant (e.g., oil) is supplied from the annular coolant flow path to various parts inside the case, thereby cooling the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-204980 Summary of the Invention [Problem 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) contacts 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. If a gap occurs between the case and the guide ring, the coolant in the annular coolant flow path will leak. This specification proposes a technology that can suppress the leakage of the coolant in the annular coolant flow path. [Means for solving the problem]

[0005] (Configuration 1) The motor of configuration 1 disclosed in this specification has a stator core, a case, a guide ring, and a seal member. The case houses the stator core. The case has a facing portion facing one end face of the stator core. The guide ring is housed within the case, has a ring shape extending around the motor shaft, and is sandwiched between the end face and the facing portion. The seal member is provided on a target interface, which is at least one of the interface between the guide ring and the end face and the interface between the guide ring and the facing 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 face. The seal member is formed of a linear member. The linear member is bent into an annular shape along the guide ring so that both ends contact each other and is sandwiched by the target interface.

[0006] In this motor, the guide ring is sandwiched between the end face of the stator core and the opposing surface of the case. Therefore, the interface between the guide ring and the end face of the stator core and the interface between the guide ring and the opposing surface of the case are sealing surfaces that form an annular coolant flow path. A sealing member is provided at at least one of these interfaces, which is the target interface, thereby preventing coolant leakage at the target interface. The sealing member is also made of a linear member. The linear member is bent into an annular shape along the guide ring so that both ends are in contact with each other and sandwiched between the target interfaces, thereby sealing the annular target interface. Because the linear member can be continuously molded by extrusion molding, it can be manufactured more efficiently than a sealing member (e.g., an O-ring) that is pre-formed into a ring shape. Therefore, the linear member can be manufactured at a lower cost than a sealing member pre-formed into a ring shape. This motor can therefore be manufactured at a lower cost. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is an exploded perspective view of the motor according to the embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the motor according to the embodiment. [Figure 3]FIG. 3 is a plan view of the stator as viewed in the axial direction. [Figure 4] FIG. [Figure 5] FIG. 4 is a plan view of the guide ring as viewed in the axial direction. [Figure 6] An enlarged view of the groove in range X (the bottom of the guide ring) in Figure 5. [Figure 7] 6 is an enlarged view of a groove and a seal member in a range X (the lowest part of the guide ring) in FIG. 5. [Figure 8] FIG. [Figure 9] FIG. 10 is an enlarged view of a wide portion 71w of a modified example. [Figure 10] FIG. 10 is a plan view of a guide ring according to a modified example, viewed in the axial direction. [Figure 11] FIG. 10 is an enlarged view of a joint portion between both end surfaces of a seal member according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] The motor disclosed in this specification may have the following configuration. (Configuration 2) 2. The motor according to claim 1, wherein the linear member has a laminated portion in which both ends are overlapped in the radial direction of the guide ring. (Configuration 3) an annular groove is provided on a surface of the guide ring that constitutes the target interface; the linear member is disposed in the annular groove, the annular groove has a narrow portion and a wide portion that is wider than the narrow portion, The laminated portion is disposed within the wide portion. 3. The motor according to claim 2. (Configuration 4) The motor according to configuration 1, wherein one end surface and the other end surface of the linear member are bonded or welded to each other. (Configuration 5) The sealing member is disposed at an angle with respect to a horizontal plane, a portion where the both ends of the linear member are in contact with each other is disposed in a range including the lowermost portion of the sealing member; The motor according to any one of the first to fourth aspects. (Configuration 6) A coolant is stored in the case, a portion where the both ends of the linear member are in contact with each other is disposed below the water level of the cooling liquid in the case; The motor according to any one of the first to fifth aspects. (Configuration 7) The motor according to any one of configurations 1 to 6, wherein an in-core coolant flow path through which the coolant supplied from the annular coolant flow path flows is provided inside the stator core. (Configuration 8) The coil ends are disposed on the inner circumferential side of the guide ring, The guide ring is provided with a coolant discharge flow path that penetrates the guide ring in the radial direction. The motor according to any one of the first to seventh aspects.

[0009] In any of the configurations 2 to 4, leakage of the coolant from the contact portions at both ends of the linear member can be suppressed.

[0010] In configuration 5, the seal member is disposed at an angle relative to the horizontal plane. In other words, the central axis of the annular seal member is inclined relative to the vertical axis. With this configuration, the coolant tends to accumulate around the bottom of the seal member, and the accumulated coolant can prevent the coolant from leaking from the contact areas between both ends of the linear member.

[0011] According to the sixth aspect, the cooling liquid stored in the case can prevent the cooling liquid from leaking from the contact portions at both ends of the linear member.

[0012] In either configuration 7 or 8, the motor can be cooled efficiently.

[0013] The motor 10 of 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 disposed in the center hole of the stator 30 so that the center axis of the shaft 24 coincides with the center axis of the stator 30. The rotor 20 and the stator 30 are housed in the case 50. Hereinafter, the direction parallel to the rotation axis of the motor 10 (i.e., the center axis of the shaft 24) is referred to as the axial direction, the direction along the radius of a circle centered on the rotation axis of the motor 10 is referred to as the radial direction, and the direction along that circle is referred to as the circumferential direction. In this embodiment, the rotation axis of the motor 10 is disposed horizontally.

[0014] The case 50 has an outer peripheral wall 52 and a partition wall 54. The outer peripheral wall 52 has a cylindrical or box 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 in the center of the partition wall 54.

[0015] The stator 30 has a stator core 32 and a coil 40. Note that FIG. 2 shows simplified coil ends 42a and 42b of the coil 40. The stator core 32 has a cylindrical shape. The coil 40 is wound around the stator core 32 (more specifically, around teeth 34, which will be described later). The stator core 32 has an end face 32a, an end face 32b, and an outer peripheral surface 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 opposite to the end face 32a. The end face 32a is provided with a coil end 42a. 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. 3, the coil ends 42a are distributed in an annular pattern on the end face 32a, and the coil ends 42b are distributed in an annular pattern on the end face 32b.

[0016] 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 surface 32c of the stator core 32. The inner surface 52a of the outer peripheral wall 52 faces the outer peripheral surface 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 protrusions 38 are provided on the outer peripheral surface 32c of the stator core 32. Furthermore, a plurality of recesses 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 protrusion 38 is positioned within the corresponding recess 58. Each protrusion 38 has a bolt fastening hole extending along the axial direction. A bolt 49 is inserted into each bolt fastening hole. The stator core 32 is fastened to a case 50 by bolts 49 .

[0017] The rotor 20 is arranged concentrically with the stator core 32 and in the center hole of 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 a bearing or the like.

[0018] As shown in FIGS. 1 and 2 , the motor 10 includes a guide ring 60. The guide ring 60 is ring-shaped and housed within the case 50. The guide ring 60 is disposed so as to extend annularly around the rotation axis (i.e., the shaft 24) of the motor 10. The guide ring 60 is disposed concentrically with the rotor 20 and the stator core 32, between the end face 32 a of the stator core 32 and the partition wall 54 of the case 50. The guide ring 60 is fixedly sandwiched between the end face 32 a and the partition wall 54. The coil end 42 a is disposed 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 space 56 and an inner space 57. The outer 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 32 a, and has an annular shape. Hereinafter, the space 56 on the outer periphery side will be referred to as an annular coolant flow path 56.

[0019] As shown in FIG. 4, the guide ring 60 has an end face 60a and an end face 60b on opposite sides in the axial direction. The end face 60a of the guide ring 60 is in contact with the end face 32a of the stator core 32. A groove 71 is provided in the end face 60a. The groove 71 extends annularly along the guide ring 60. A seal member 66 is provided in the groove 71. The seal member 66 is fixed in the groove 71 by being sandwiched and pressurized between the stator core 32 and the guide ring 60. The seal member 66 seals the interface (i.e., the contact surface) between the guide ring 60 and the stator core 32.

[0020] FIG. 5 shows the seal member 66 and groove 71 as viewed in the axial direction. As shown in FIG. 5, the groove 71 extends annularly along the end surface 60a of the guide ring 60. As shown in FIG. 6, the groove 71 has a wide portion 71w and a narrow portion 71n. The wide portion 71w is wider than the narrow portion 71n. The wide portion 71w is located at a position that includes the bottom of the groove 71. The portion of the groove 71 other than the wide portion 71w is composed of the narrow portion 71n. The seal member 66 is composed of a linear member made of rubber. As shown in FIG. 5, the linear member is a linear member that extends from the tip surface 66c to the tip surface 66d. The linear member is fitted into the groove 71 to form an annular shape. The seal member 66 is composed of an annular linear member. The seal member 66 is positioned so that its central axis coincides with the rotational axis of the motor 10. Therefore, the seal member 66 is disposed perpendicular to the horizontal plane. As shown in FIG. 7, a portion of the linear member near the tip surface 66c (hereinafter referred to as the end 66a) and a portion near the tip surface 66d (hereinafter referred to as the end 66b) are radially overlapped within the wide portion 71w. The end portions 66a and 66b are pressed radially by being sandwiched between both side surfaces of the wide portion 71w. Therefore, the end portions 66a and 66b are in close contact with each other. The overlapping portion of the end portions 66a and 66b is disposed at the bottom of the seal member 66.

[0021] As shown in FIG. 4, the end face 60b of the guide ring 60 contacts the inner surface of the partition wall 54 of the case 50. A groove 72 is formed in the end face 60b. The groove 72 extends annularly along the guide ring 60. A seal member 68 is provided in the groove 72. The seal member 68 is fixed in the groove 72 by being sandwiched and pressurized between the partition wall 54 and the guide ring 60. The seal member 68 seals the interface (i.e., the contact surface) between the guide ring 60 and the partition wall 54.

[0022] The seal member 68 and groove 72 are arranged in the same manner as the seal member 66 and groove 71 shown in FIGS. 5 to 7. In FIGS. 5 to 7, the reference numerals corresponding to the seal member 68 and groove 72 are written in parentheses. As shown in FIG. 5, the groove 72 extends annularly along the end surface 60b of the guide ring 60. As shown in FIG. 6, the groove 72 has a wide portion 72w and a narrow portion 72n. The wide portion 72w is wider than the narrow portion 72n. The wide portion 72w is located at a position that includes the bottom of the groove 72. The portion of the groove 72 other than the wide portion 72w is made up of the narrow portion 72n. The seal member 68 is made up of a linear member made of rubber. As shown in FIG. 5, the linear member is a linear member that extends from the tip surface 68c to the tip surface 68d. The linear member is fitted into the groove 72 to form an annular shape. The seal member 68 is made up of a ring-shaped linear member. The seal member 68 is disposed so that its central axis coincides with the rotational axis of the motor 10. Therefore, the seal member 68 is disposed perpendicular to the horizontal plane. As shown in FIG. 7 , a portion of the linear member near a tip end surface 68c (hereinafter referred to as end 68a) and a portion near a tip end surface 68d (hereinafter referred to as end 68b) are radially overlapped within the wide portion 72w. The ends 68a and 68b are pressed radially by being sandwiched between both side surfaces of the wide portion 72w. Therefore, the ends 68a and 68b are in close contact with each other. The overlapping portion of the ends 68a and 68b is disposed at the bottom of the seal member 68.

[0023] As shown in Fig. 4, a step portion 59 is provided on the inner surface 52a of the case 50. The step portion 59 is provided over the entire circumferential area. The end face 32a of the stator core 32 is in contact with the step portion 59 in the axial direction. The end face 32a is in close contact with the step portion 59. A sealing member (e.g., an O-ring, a metal gasket, a liquid gasket, etc.) may be provided at the interface between the end face 32a and the step portion 59.

[0024] A coolant supply path 53a is provided in the case 50. The coolant supply path 53a connects the outside of the case 50 to the annular coolant flow path 56. As shown in FIG. 2, a coolant discharge path 53b is provided in the lower part of the case 50. The coolant discharge path 53b connects the inside and outside of the case 50. The coolant discharge path 53b is connected to the coolant supply path 53a via a circulation path (not shown) provided outside the case 50. A pump (not shown) is provided in the circulation path. A coolant is stored inside the case 50. When the pump is operated, the coolant inside the case 50 is supplied to the annular coolant flow path 56 via the coolant discharge path 53b and the coolant supply path 53a. As will be described in detail later, the coolant supplied to the annular coolant flow path 56 is discharged into the inside of the case 50. In this manner, the coolant circulates between the circulation path and the case 50. In this embodiment, the coolant is cooling oil. The cooling oil functions as a coolant that cools the motor 10 and also as a lubricant that lubricates the rotor 20 .

[0025] 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 radial direction. As shown in Fig. 1, the guide ring 60 is provided with a plurality of coolant discharge passages 62 dispersed in the circumferential direction. As shown in Fig. 4, the annular coolant passage 56 and a space 57 (i.e., the space in which the coil end 42a is present) are connected by the coolant discharge passages 62. Each coolant discharge passage 62 discharges the coolant in the annular coolant passage 56 toward the coil end 42a.

[0026] As shown in FIG. 8, the stator core 32 is made up of a plurality of electromagnetic steel plates 36 stacked 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 protrudes from the inner circumferential surface of the back yoke 33. That is, each tooth 34 protrudes 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. 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 end 42a is located radially inward of the guide ring 60.

[0027] As shown in Fig. 2, multiple in-core coolant flow paths 39 are provided inside the stator core 32. Each in-core coolant flow path 39 extends along the axial direction. One end of each in-core coolant flow path 39 opens to the end face 32a and is connected to the annular coolant flow path 56. The other end of each in-core coolant flow path 39 opens to the end face 32b. The multiple in-core coolant flow paths 39 are provided dispersed in the circumferential direction.

[0028] When the motor 10 is operating, the coolant is supplied from the coolant supply path 53a to the annular coolant flow path 56. The coolant in the annular coolant flow path 56 flows to the coolant discharge path 62 and the in-core coolant flow path 39. The coolant in the coolant discharge path 62 is discharged toward the coil ends 42a, thereby cooling the coil ends 42a. The coolant discharged toward the coil ends 42a flows toward the bottom of the case 50. The coolant flowing through the in-core coolant flow path 39 cools the stator core 32. The coolant in the in-core coolant flow path 39 is discharged from the end face 32b into the case 50. The coolant discharged from the end face 32b cools the coil ends 42b. The coolant discharged from the end face 32b flows toward the bottom of the case 50. The coolant that has flowed to the bottom of the case 50 and accumulated in the case 50 is sent from the coolant discharge path 53b to the coolant supply path 53a via an external pump. In this way, the motor 10 is cooled by circulating the coolant.

[0029] In the motor 10, the guide ring 60 is sandwiched between the case 50 and the stator core 32 in the axial direction. With this configuration, it is possible to apply pressure to the interface between the guide ring 60 and the case 50 and the interface between the guide ring 60 and the stator core 32. Appropriate pressure is applied to the seal members 66, 68, so these interfaces can be properly sealed. This prevents leakage of the coolant at each interface and allows accurate control of the flow rate of the coolant in each flow path.

[0030] The seal members 66, 68 are formed from a linear member bent into an annular shape around the guide ring 60. A linear member can be efficiently manufactured by extrusion molding or other methods, resulting in low manufacturing costs. Therefore, using a linear member as a seal member reduces the manufacturing cost of the motor 10. The seal members 66, 68 can be installed in the manufacturing process of the motor 10 as follows. First, a very long linear rubber member wound on a bobbin or the like is cut to a predetermined length to prepare the linear member. Next, the linear member is fitted into the grooves 71, 72, forming an annular shape and positioned within the grooves 71, 72. Next, the guide ring 60 and the stator core 32 are assembled into the case 50 so that the guide ring 60 is sandwiched between the partition wall 54 and the stator core 32. This allows the seal members 66, 68 to be properly installed within the case 50.

[0031] In addition, in the sealing members 66, 68, both ends of the linear members are stacked in the radial direction and in close contact with each other. This prevents the coolant from leaking from the stacked portions at both ends. In order to further improve the sealing performance of the stacked portions at both ends, protrusions 80 may be provided on the side surfaces of the wide portions, as shown in FIG. 9.

[0032] The dashed line 100 in Figure 5 indicates the level of the coolant that accumulates inside the case 50 while the motor 10 is in operation. As shown in Figure 5, the lowermost parts of the guide ring 60 and the seal members 66, 68 are located below the coolant level 100. As a result, the laminated portions at both ends of the linear member are immersed in the coolant. This makes it more difficult for the coolant to leak from the laminated portions at both ends.

[0033] 5, the stacked portions of the linear members are arranged at the lowest parts of the sealing members 66 and 68, but leakage of the coolant at the stacked portions can be suppressed no matter where the stacked portions are arranged as long as the stacked portions are arranged below the liquid level 100. For example, as shown in FIG. 10, the stacked portions of the linear members may be arranged at a position that does not include the lowest parts of the sealing members 66 and 68.

[0034] In the above-described embodiment, both ends of the linear member are stacked in the radial direction. However, as shown in Fig. 11, the tip surfaces 66c and 66d on both sides of the linear member may be welded or glued to each other. Even in this configuration, an annular seal member can be formed using the linear member.

[0035] Although the embodiments have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or 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. Furthermore, the technology exemplified in this specification or drawings simultaneously achieves multiple objectives, and achieving one of these objectives itself has technical utility. [Explanation of symbols]

[0036] 32: stator core, 39: coolant flow path in core, 42a: coil end, 50: case, 54: partition wall, 56: annular coolant flow path, 60: guide ring, 62: coolant discharge flow path, 66, 68: seal members, 71, 72: grooves

Claims

1. A motor, A stator core; a case that houses the stator core and has a facing portion that faces one end surface of the stator core; a guide ring housed in the case, having a ring shape extending around the motor shaft, and sandwiched between the end face and the opposing portion; a seal member provided at a target interface, which is at least one of an interface between the guide ring and the end face and an interface between the guide ring and the opposing portion; and 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; The sealing member is formed of a linear member, The linear member is bent into a ring shape along the guide ring so that both ends thereof are in contact with each other, and is sandwiched between the target interface. Motor.

2. The motor according to claim 1 , wherein the linear member has a laminated portion in which the both end portions are laminated in the radial direction of the guide ring.

3. an annular groove is provided on a surface of the guide ring that constitutes the target interface; the linear member is disposed in the annular groove, the annular groove has a narrow portion and a wide portion that is wider than the narrow portion, The laminated portion is disposed within the wide portion. The motor according to claim 2 .

4. 2. The motor according to claim 1, wherein one end surface of said linear member and the other end surface of said linear member are bonded or welded to each other.

5. The sealing member is disposed at an angle with respect to a horizontal plane, a portion where the both ends of the linear member are in contact with each other is disposed in a range including the lowermost portion of the sealing member; The motor according to any one of claims 1 to 4.

6. A coolant is stored in the case, a portion where the both ends of the linear member are in contact with each other is disposed below the water level of the cooling liquid in the case; The motor according to any one of claims 1 to 4.

7. 5. The motor according to claim 1, wherein an in-core coolant flow passage is provided inside the stator core, through which the coolant supplied from the annular coolant flow passage flows.

8. The coil ends are disposed on the inner circumferential side of the guide ring, The guide ring is provided with a coolant discharge flow path that penetrates the guide ring in the radial direction. The motor according to any one of claims 1 to 4.

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