JP2016046853A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which attains downsizing in an axial direction and is capable of reducing the number of fastening members.SOLUTION: The rotary electric machine includes: a housing 12 which is formed cylindrical by die-casting and includes a coolant flow passage 20 that is opened in a circumferential direction on one end face in the axial direction; a front plate 13 which closes an opening 20e of the coolant flow passage 20 in the housing 12 via a metal gasket 30; a rotor 17 which is supported in a rotatable manner within the housing 12; a stator 16 which is fixed within the housing 12; and a bolt which generates an axial force in the front plate 13 and a bottom part 47 of the coolant flow passage 20 of the housing 12 and generates bearing on sealing surfaces between an outer diameter side and an inner diameter side of the coolant flow passage 20 and the front plate 13 on the end face of the housing 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotating electrical machine.

  As a cooling structure for a motor for driving a vehicle, a structure in which a refrigerant flow path is provided in a cylindrical housing in which a rotor and a stator are disposed inside, and a refrigerant flow path is formed in the housing by casting is proposed. The refrigerant flow path formed in the housing is disposed so as to surround the outer periphery of the stator, which is the main heat generating portion of the motor, and thereby appropriate cooling is performed. Since the housing having such a refrigerant flow path is usually molded using a core of a casting, the housing is inferior in mass productivity and causes a high cost. In contrast, a housing is formed by die casting (for example, Patent Document 1).

JP 2008-253024 A

  By the way, when the housing is formed by die casting, a plate is fastened to the end surface of the housing with a bolt or the like via a gasket, and the opening of the coolant channel is closed by the gasket. In this way, the refrigerant flow path has a structure in which one side is open, and in order to ensure the sealing performance by securing the gasket surface pressure, the inner diameter side and the outer diameter side of the opening of the refrigerant flow path on the housing end surface are provided. Bolt holes need to be disposed respectively, and the physique becomes large due to the arrangement of the boss portions for fastening the bolts.

  An object of the present invention is to provide a rotating electrical machine capable of reducing the number of fastening members while reducing the axial size.

  According to the first aspect of the present invention, a housing having a refrigerant flow path that is formed in a cylindrical shape by die casting and that opens along the circumferential direction at least at one end face in the axial direction, and an opening portion of the refrigerant flow path in the housing is provided. Axial force is applied to the lid member that is closed via the seal member, the rotor that is rotatably supported in the housing, the stator that is fixed in the housing, and the bottom of the refrigerant flow path of the lid member and the housing. And a fastening member that generates a surface pressure on the sealing surface between the outer diameter side and the inner diameter side of the refrigerant flow path on the end surface of the housing and the lid member.

  According to the first aspect of the present invention, when the opening of the refrigerant flow path is closed, the fastening member causes an axial force to be generated on the lid member and the bottom of the refrigerant flow path of the housing so that the refrigerant flow on the end surface of the housing Surface pressure is generated on the seal surface between the outer and inner diameter sides of the path and the lid member. As a result, the surface pressure of the seal member is ensured and the sealing performance is ensured. That is, it is not necessary to dispose bolt holes on the inner diameter side and the outer diameter side of the refrigerant flow path on the end surface of the housing, so that the axial size can be reduced and the number of fastening members can be reduced.

As described in claim 2, in the rotating electrical machine according to claim 1, the fastening member may be disposed in the refrigerant flow path.
As described in claim 3, in the rotating electrical machine according to claim 2, the fastening member may be disposed in a partition portion formed between a refrigerant inlet and a refrigerant outlet in the refrigerant flow path.

As described in claim 4, in the rotating electrical machine according to claim 1, the fastening member may be disposed outside the refrigerant flow path.
As described in claim 5, in the rotating electrical machine according to any one of claims 1-4, the fastening member may be a bolt.

  According to the present invention, the axial size can be reduced and the number of fastening members can be reduced.

The sectional side view which shows the motor in embodiment. Sectional drawing in the AA of FIG. Sectional drawing in the BB line of FIG. Sectional drawing which shows the motor of another example. The sectional side view which shows the motor of another example. The sectional side view which shows the motor for a comparison.

  Hereinafter, an embodiment in which the present invention is embodied in a motor (rotary electric motor) as a rotating electrical machine will be described. In addition, the motor of this embodiment is mounted in a vehicle in order to transmit the rotational driving force of the drive shaft to the drive wheels via the speed reducer.

  As shown in FIG. 1, the motor 11 includes a cylindrical housing 12, a disk-shaped front plate 13 that closes one end opening 12 a of the housing 12, and a disk that closes the other end opening 12 b of the housing 12. Shaped rear plate 14 is provided. The housing 12, the front plate 13, and the rear plate 14 are made of a metal material (for example, aluminum) and are manufactured by die casting. Therefore, the housing 12, the front plate 13, and the rear plate 14 can be produced at low cost.

  A drive shaft 15 is accommodated in the housing 12. The output end side (one end side) of the drive shaft 15 is rotatably supported by a cylindrical first shaft support portion 131 protruding from the front plate 13 via a first bearing Be1. The counter-output end side (the other end side) of the drive shaft 15 is rotatably supported by a cylindrical second shaft support portion 141 protruding from the rear plate 14 via a second bearing Be2. The output end of the drive shaft 15 penetrates through the front plate 13 and protrudes outward. A transmission (not shown) is attached to the output end of the drive shaft 15. In addition, since the radial load acting on the drive shaft 15 from the transmission side when driving the transmission is larger than that on the non-output end side of the drive shaft 15 at the output end side of the drive shaft 15, this radial load. So that the first bearing Be1 is larger than the second bearing Be2. In addition, an annular flange 13 a for attaching the motor 11 to the transmission side is formed on the outer peripheral portion of the front plate 13.

  A stator (stator) 16 is fixed in the housing 12. The stator 16 is inserted into the housing 12 through the other end opening 12b of the housing 12, and the stator core 16a is fixed to the inner peripheral surface of the housing 12 by shrink fitting. The stator 16 is configured by winding a coil 16 b around a tooth (not shown) of an annular stator core 16 a fixed to the inner peripheral surface of the housing 12. Coil ends 16c protrude from both end surfaces in the axial direction of the drive shaft 15 in the stator core 16a. The stator core 16a is configured by laminating a plurality of magnetic bodies (electromagnetic steel plates).

  A rotor (rotor) 17 is rotatably supported in the housing 12. Specifically, a rotor 17 that rotates integrally with the drive shaft 15 is disposed inside the stator 16. The rotor 17 includes a rotor core 17a fixed to the drive shaft 15 and a plurality of permanent magnets 17b embedded in the rotor core 17a. The rotor core 17a is configured by laminating a plurality of magnetic bodies (electromagnetic steel plates).

  An annular flange portion 15 a that protrudes radially outward of the drive shaft 15 from the outer peripheral surface of the drive shaft 15 is formed on the side opposite to the output end of the drive shaft 15. The end face of the rotor core 17a on the side opposite to the output end of the drive shaft 15 is in contact with the flange portion 15a. Further, on the outer peripheral surface of the drive shaft 15, a fixing member 18 (for example, a nut) is disposed between the end surface of the rotor core 17a on the output end side of the drive shaft 15 and the first bearing Be1. The fixing member 18 is attached to the outer peripheral surface of the drive shaft 15 from the output end side of the drive shaft 15. And the rotor core 17a is pinched | interposed between the fixing member 18 and the flange part 15a, and the movement to the axial direction of the drive shaft 15 is controlled.

  An annular oil seal 19 is disposed between the outer peripheral surface of the drive shaft 15 and the front plate 13. The oil seal 19 is located closer to the output end of the drive shaft 15 than the first bearing Be1. The oil seal 19 prevents foreign matter from entering the motor from the outside via the space between the outer peripheral surface of the drive shaft 15 and the front plate 13.

  An annular coolant channel (water jacket) 20 that extends in the axial direction of the drive shaft 15 and surrounds the stator 16 and the rotor 17 is formed in the housing 12. The refrigerant channel 20 has an inner wall surface 20a on the inner diameter side and an inner wall surface 20b on the outer diameter side. Moreover, the refrigerant | coolant flow path 20 has the refrigerant | coolant inlet 20c and the refrigerant | coolant outlet 20d, as shown in FIG. Further, as shown in FIG. 1, the refrigerant flow path 20 has an opening 20 e on the output end side of the drive shaft 15.

  A refrigerant for cooling the motor 11 flows in the refrigerant flow path 20. Cooling water is used as the refrigerant. The refrigerant flow path 20 opens on the output end side of the drive shaft 15 in the axial direction of the drive shaft 15 and is closed on the opposite output end side of the drive shaft 15. Here, since the housing 12 is manufactured by die casting, the coolant flow path 20 injects a molten metal material (aluminum) into the mold, and after the molten metal material is solidified, the mold is easily pulled out. In order to be able to do so, the diameter is increased toward the opening side. That is, the refrigerant flow path 20 has a gradient for die cutting.

  In this way, the housing 12 is formed in a cylindrical shape by die casting, and has the refrigerant flow path 20 that opens along the circumferential direction on one end face. The opening 20 e of the refrigerant flow path 20 is closed by the front plate 13 via a metal gasket 30 as a seal member, and the refrigerant in the refrigerant flow path 20 is sealed by the metal gasket 30. Therefore, in the present embodiment, the front plate 13 corresponds to a lid member that closes the opening 20 e of the refrigerant flow path 20 in the housing 12 via the metal gasket 30.

As shown in FIG. 1, the rear plate 14 is attached to the housing 12 by bolts 31.
As shown in FIG. 1, the rear plate 14 is provided with a refrigerant inlet pipe 21 communicating with the refrigerant flow path 20, and the refrigerant is supplied from the refrigerant inlet pipe 21 to the refrigerant flow path 20. The rear plate 14 is provided with a refrigerant outlet pipe 22 communicating with the refrigerant flow path 20, and the refrigerant after passing through the refrigerant flow path 20 is discharged to the refrigerant outlet pipe 22.

  The refrigerant flow path 20 extends in the circumferential direction, and as shown in FIGS. 2 and 3, a partition portion 23 extending in the axial direction is provided in a part of the circumferential direction. As shown in FIG. 2, the refrigerant flow path 20 is provided with a refrigerant inlet 20 c and a refrigerant outlet 20 d separated from each other on one side surface in the axial direction. And the refrigerant | coolant which entered from the refrigerant | coolant inlet 20c flows toward the other side surface in the refrigerant | coolant flow path 20, while flowing along the circumferential direction, and comes out from the refrigerant | coolant outlet 20d.

  As shown in FIGS. 1 and 2, bolts 41, 42, 43, 44, 45 and 46 are provided as fastening members. Bolt holes 48 are formed in the bottom surface (back side in the axial direction) of the refrigerant flow path 20 in the housing 12. Bolts 41, 42, 43, 44, 45, 46 extending through the front plate 13 in the axial direction are screwed into the bolt holes 48. The bolts 41, 42, 43, 44, 45, 46 for fastening the front plate 13 are disposed in the refrigerant flow path 20, and are disposed in the central portion in the radial direction of the refrigerant flow path 20. Bolts 41 to 46 are made of stainless steel. The bolts 41 to 46 are arranged at equal intervals in the circumferential direction of the drive shaft 15.

  The bolts 41, 42, 43, 44, 45, 46 generate an axial force on the front plate 13 and the bottom 47 of the refrigerant flow path 20 of the housing 12 formed by die casting, so that the refrigerant flow path at the end face of the housing 12 is obtained. Surface pressure is generated on the seal surface between the front plate 13 and the outer diameter side (end surface 12 c) and the inner diameter side (end surface 12 d) of 20.

Next, the operation of this embodiment will be described.
The refrigerant flow path 20 of the housing 12 has an opening on one side and the opening surface is a sealing surface. Bolt holes 48 are provided on the opposite side of the sealing surface, and surface pressure is applied to both sides of the inner diameter and outer diameter of the refrigerant flow path 20. To seal. That is, the seal surface pressure is applied by the axial force by the bolts 41 to 46 extending in the axial direction between the bottom 47 of the refrigerant flow path 20 in the axial direction and the front plate 13. Therefore, when closing the opening 20 e of the refrigerant flow path 20, the bolts 41 to 46 generate an axial force on the front plate 13 and the bottom 47 of the refrigerant flow path 20 of the housing 12 to cause the refrigerant flow on the end surface of the housing 12. Surface pressure is generated on the seal surface between the outer diameter side (end surface 12 c) and inner diameter side (end surface 12 d) of the path 20 and the front plate 13.

  FIG. 6 is a sectional view of a motor for comparison. In FIG. 6, the front plate 13 includes a plurality of inner diameter side bolts 100 as fastening members disposed on the inner diameter side of the refrigerant flow path 20 and a plurality of outer members as fastening members disposed on the outer diameter side of the refrigerant flow path 20. A radial bolt 101 is attached to the housing 12. The inner diameter side bolts 100 and the outer diameter side bolts 101 are arranged at equal intervals in the circumferential direction of the drive shaft 15.

  In FIG. 6, sealing is performed by pulling the housing with the force indicated by F <b> 10 and F <b> 11 and pressing with the forces F <b> 12 and F <b> 13 as the bolts 100 and 101 are fastened. The refrigerant flow path 20 has a structure in which one side is opened, and in order to secure the surface pressure of the metal gasket 30 and ensure the sealing performance, the refrigerant flow path 20 is respectively provided on the inner diameter side and the outer diameter side of the refrigerant flow path 20 on the end surface of the housing 12. Bolt holes need to be disposed, and the physique becomes large due to the arrangement of the boss portions for fastening the bolts. Specifically, in FIG. 6, the boss portion for fastening the inner diameter side bolt 100 projects by a thickness t1 in the radial direction and a length L1 in the axial direction. In FIG. 6, the boss portion for fastening the outer diameter side bolt 101 projects by a thickness t2 in the radial direction and a length L2 in the axial direction.

  In this embodiment, as shown in FIG. 1, the bolt hole 48 is arrange | positioned in the radial direction center part and axial direction back side of the refrigerant flow path 20, and the bolts 41-46 are screwed in. In FIG. 1, the housing 12 is pulled by the force indicated by F1, and sealing is performed by simultaneously pressing both the forces F2 and F3. Thereby, the surface pressure of the metal gasket 30 is ensured and the sealing performance is ensured. That is, the housing 12 is provided with the bolt holes 48 in the portion where the inner diameter side and the outer diameter side of the refrigerant flow path 20 in the housing 12 are connected, that is, the bottom surface (bottom 47) of the refrigerant flow path 20. The bolt axial force is evenly transmitted to the inner diameter side and the outer diameter side of the refrigerant flow path 20 in the above, and the seal surface pressure of the front plate 13 is ensured.

  In FIG. 1, the number of bolts can be halved while ensuring sealing performance. Specifically, in the case of FIG. 6, for example, seven outer diameter-side bolts 101 and seven inner-diameter bolts 100 are required, for example, 14 in total, but in the case of FIGS. . That is, it is not necessary to dispose bolt holes on the inner diameter side and the outer diameter side of the refrigerant flow path 20 on the end face of the housing 12 in FIG. Thereby, the lengths L1 and L2 of the projecting portions in the axial direction of the boss portions for fastening the bolts 100 and 101 in FIG. 6 can be made unnecessary, and the axial size can be reduced. Further, the thicknesses t1 and t2 of the projecting portions in the radial direction in the boss portions for fastening the bolts 100 and 101 in FIG. 6 can be made unnecessary, and the size in the radial direction can be reduced. Furthermore, the number of bolts as fastening members can be reduced.

Moreover, since the bolt as a fastening member also functions as a strength member as the housing strength, the inner wall surfaces 20a, 20b and the like can be made thinner than in the conventional structure.
According to the above embodiment, the following effects can be obtained.

  (1) The configuration of the motor 11 includes a housing 12, a front plate 13, a rotor 17, and a stator 16. Further, an axial force is generated at the front plate 13 and the bottom 47 of the refrigerant flow path 20 of the housing 12, so that the end face of the housing 12 faces the seal surface between the outer diameter side and the inner diameter side of the refrigerant flow path 20 and the front plate 13. Bolts 41, 42, 43, 44, 45, and 46 for generating pressure were provided. Therefore, it is possible to reduce the size in the axial direction and reduce the number of fastening members. Moreover, it can be reduced in size in the radial direction.

(2) Bolts 41, 42, 43, 44, 45, 46 are arranged in the refrigerant flow path 20. Therefore, it is possible to reduce the size in the radial direction.
(3) Since the fastening members are bolts 41, 42, 43, 44, 45, 46, an axial force is easily applied.

The embodiment is not limited to the above, and may be embodied as follows, for example.
As shown in FIG. 4 instead of FIG. 3, a bolt 49 that also serves as a refrigerant partitioning member may be inserted in the shorter direction between the refrigerant inlet 20 c and the refrigerant outlet 20 d in the circumferential direction in the refrigerant flow path 20. That is, the bolt 49 may be disposed in a partition portion formed between the refrigerant inlet 20c and the refrigerant outlet 20d in the refrigerant flow path 20. In this case, it is preferable to change the shapes of the inner wall surfaces 20a and 20b and the bottom portion 47 so that the flow passage area is smaller than the other bolt portions. In FIG. 2, the rigidity varies depending on the partition portion 23, but the rigidity can be made uniform by configuring the partition with bolts 49 as shown in FIG. 4. In this way, the bolts 49 are arranged in the partition portion formed between the coolant inlet 20c and the coolant outlet 20d in the coolant channel 20, so that the strength of the bolt 49 is more uniform than when the partition portion is formed only by die casting. Can be achieved.

  As shown in FIG. 5 instead of FIG. 1, the bolt 51 passes through the outer diameter side of the refrigerant flow path 20, and the bolt hole 52 formed in the boss portion 50 disposed on the opposite side of the refrigerant flow path 20 The front plate 13 may be fastened and fixed by screwing bolts 51. That is, a boss portion 50 that protrudes to the outer diameter side with respect to the bottom portion 53 of the refrigerant flow path 20 is provided, and the bolt 51 is screwed into the bolt hole 52 of the boss portion 50 through the front plate 13 and fastened and fixed. Also good.

  As described above, the bolt 51 as the fastening member may be arranged outside the refrigerant flow path 20. In this case, corrosion of the bolt 51 is less likely to occur, and pressure loss can be reduced in the refrigerant flow. Specifically, it is useful when a bolt is arranged in the central portion in the radial direction of the refrigerant flow path 20 so that there is no margin for pressure loss when the refrigerant flows through the refrigerant flow path 20, for example, when the pump capacity is small. Further, the lengths L1 and L2 of the projecting portions in the axial direction in the boss portions for fastening the bolts 100 and 101 in FIG. 6 can be eliminated, and the size can be reduced in the axial direction. Further, the seal around the hole through which the bolt 51 in the front plate 13 passes becomes unnecessary.

  -Although the refrigerant | coolant flow path 20 of the housing 12 was opened to one end surface of an axial direction, ie, one side, you may open to both surfaces. In short, the housing 12 only needs to have a refrigerant flow path (20) that opens along the circumferential direction at least on one end face in the axial direction.

  -A fastening member is not restricted to a volt | bolt, For example, a rivet may be sufficient.

  DESCRIPTION OF SYMBOLS 11 ... Motor, 12 ... Housing, 13 ... Front plate, 16 ... Stator, 17 ... Rotor, 20 ... Refrigerant flow path, 20c ... Refrigerant inlet, 20d ... Refrigerant outlet, 30 ... Metal gasket, 41 ... Bolt, 42 ... Bolt, 43 ... Bolt, 44 ... Bolt, 45 ... Bolt, 46 ... Bolt, 47 ... Bottom, 49 ... Bolt, 51 ... Bolt, 53 ... Bottom.

Claims (5)

A housing that is formed in a cylindrical shape by die casting and has a refrigerant flow path that opens at least in one axial end surface along the circumferential direction;
A lid member for closing the opening of the refrigerant flow path in the housing via a seal member;
A rotor rotatably supported in the housing;
A stator fixed in the housing;
An axial force is generated on the lid member and the bottom of the refrigerant flow path of the housing to generate a surface pressure on the seal surface between the outer diameter side and the inner diameter side of the refrigerant flow path and the lid member on the end surface of the housing. A fastening member to be
A rotating electrical machine comprising:   The rotating electrical machine according to claim 1, wherein the fastening member is disposed in the refrigerant flow path.   The rotating electrical machine according to claim 2, wherein the fastening member is disposed in a partition portion formed between a refrigerant inlet and a refrigerant outlet in the refrigerant flow path.   The rotating electrical machine according to claim 1, wherein the fastening member is disposed outside the refrigerant flow path.   The rotating electrical machine according to claim 1, wherein the fastening member is a bolt.