JP2011078148A - Cooling structure of electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more properly cool an electric motor by securing the amount of a refrigerant necessary for cooling a stator coil. <P>SOLUTION: In a motor unit 10, a cooling pipe 28 having openings 28a, 28b located above coil ends 25, 26 of the stator coil 24 is arranged outside a fixed ring 27 to be substantially in parallel with the central axis of a rotor 21. Then, a flow regulation wall 27b which regulates a cooling oil flowing out of the opening 28b from flowing into an outer peripheral face of a cylinder 27a is extended from the cylinder 27a of the fixed ring 27 toward the vicinity of the opening 28b of the cooling pipe 28. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling structure for an electric motor.

  Conventionally, a cooling structure for this type of motor has been proposed in which cooling oil flows out from a cooling pipe fixed to a casing that houses the motor toward the coil end portion of the stator coil to cool the coil ( For example, see Patent Document 1). In this electric motor cooling structure, a support ring provided at one end of the cooling pipe is brought into contact with the casing, and a rubber cap provided at the other end of the cooling pipe is press-fitted into the casing to fix the cooling pipe to the casing. The Accordingly, since the vibration is absorbed by the rubber cap, the cooling pipe can be firmly fixed to the casing even during vibration.

JP 2007-209160 A

  However, in the motor cooling structure described above, the cooling oil is discharged from the discharge port formed on the side surface of the cooling pipe toward the coil end portion of the stator coil, so that the cooling oil reaches a portion other than the stator coil. In other words, the cooling oil cannot be stably supplied to the coil end portion, and the cooling oil amount necessary for cooling the stator coil cannot be secured, and the cooling performance of the electric motor may be deteriorated.

  The main object of the cooling structure of the electric motor of the present invention is to secure a refrigerant amount necessary for cooling the stator coil and to cool the electric motor better.

  The motor cooling structure of the present invention employs the following means in order to achieve the above-mentioned main object.

The cooling structure of the electric motor of the present invention is
A plurality of divided cores arranged in an annular shape, a fixing member having a cylindrical portion for fixing the plurality of divided cores, and a winding wound around each of the plurality of divided cores Cooling structure for an electric motor comprising a stator including a stator coil having a coil end portion protruding from both sides of the cylindrical portion without being covered by the cylindrical portion of the fixing member, and a rotor disposed in the stator In
An opening that is disposed outside the fixed member so as to be substantially parallel to the central axis of the rotor, is connected to a coolant supply source for cooling the electric motor, and is located above one of the coil end portions A refrigerant passage having a portion,
The fixing member extends from the tubular portion to the vicinity of the opening of the refrigerant passage, and restricts the refrigerant flowing out of the opening from flowing into the outer peripheral surface of the tubular portion. It is characterized by having.

  In the motor cooling structure of the present invention, the refrigerant passage having an opening located above one of the coil end portions of the stator coil is disposed outside the stator fixing member so as to be substantially parallel to the central axis of the rotor. . An inflow restricting wall that restricts the refrigerant flowing out from the opening of the refrigerant passage from flowing into the outer peripheral surface of the cylindrical portion extends from the cylindrical portion of the stator fixing member to the vicinity of the opening of the refrigerant passage. ing. As a result, the refrigerant can be introduced into the coil end portion without flowing into the outer peripheral surface of the cylindrical portion of the fixing member, so that the amount of refrigerant necessary for cooling the stator coil is secured and the electric motor is cooled better. It becomes possible to do.

  The cooling structure of the electric motor includes an outflow restriction wall that is positioned in the vicinity of the opening of the refrigerant passage so as to face the inflow restriction wall and restricts the refrigerant from flowing beyond the coil end portion. Further, it may be provided. As a result, the refrigerant can be introduced into the coil end portion without flowing out beyond the coil end portion, so that the amount of refrigerant necessary for cooling the stator coil can be ensured and the electric motor can be cooled even better. It becomes possible.

  Further, the cooling structure of the electric motor includes the outflow regulating wall and is positioned in the vicinity of the opening of the refrigerant passage, receives the refrigerant flowing out of the opening, and passes the received refrigerant to the coil end portion. And a refrigerant receiving part that drops.

  The refrigerant passage is disposed offset from the top of the stator, and the refrigerant receiving portion receives the refrigerant flowing out from the opening of the refrigerant passage, and the received refrigerant is near the top. And may be dropped onto the coil end portion. As a result, even if the refrigerant passage is offset from the top of the stator, the refrigerant can be dropped from the vicinity of the top of the stator coil to the coil end, so that the refrigerant can be uniformly supplied to the entire stator coil. Thus, it becomes possible to cool the electric motor better.

It is a perspective view which shows the principal part of the motor unit 10 which has the cooling structure of the motor 20 which concerns on the Example of this invention. It is a front view which shows the principal part of the motor unit 10 which has the cooling structure of the motor 20 which concerns on the Example of this invention. It is sectional drawing which shows the AA cross section in FIG.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a perspective view illustrating a main part of a motor unit 10 having a cooling structure for a motor 20 according to an embodiment of the present invention, and FIG. 2 is a front view of the motor unit 10. A motor unit 10 shown in these drawings is mounted on a vehicle and outputs driving power, or recovers kinetic energy of the vehicle to generate electric power. The motor unit 10 of the embodiment is connected to a motor 20 configured as a PM-type synchronous generator motor housed in a casing (not shown) and a cooling oil pump (not shown) that supplies cooling oil for cooling the motor 20. And a cooling pipe 28 fixed to the casing.

  The motor 20 includes a rotor 21 that rotates around a rotation axis and a stator 22 that has a hollow portion that accommodates the rotor 21 in the center. The rotor 21 has a plurality of permanent magnets embedded in a rotor core formed by laminating a plurality of substantially annular plates. The plate body constituting the rotor core is formed into a plate shape and a substantially annular shape by punching an electromagnetic steel plate that is a magnetic material such as iron. As shown in FIG. 2, the stator 22 includes a stator core 23 composed of a plurality of divided cores 23a arranged in an annular shape, a fixing ring 27 having a cylindrical portion 27a for fixing the plurality of divided cores 23a, and a stator core. And a stator coil 24 composed of windings wound around each of the split cores 23a constituting the core 23a. The split core 23a may be formed by laminating a plurality of electromagnetic steel plates that are magnetic materials such as iron, or may be a powder magnetic material obtained by compression-molding magnetic powder with a molding die. In addition, the axial length of the cylindrical portion 27a of the fixing ring 27 is shorter than the axial length of the stator coil 24, so that the stator coil 24 is not covered by the cylindrical portion 27a. Coil end portions 25 and 26 projecting from.

  As shown in FIG. 1 and FIG. 2, the cooling pipe 28 is fixed to the casing so as to be substantially parallel to the central axis of the rotor 21 and offset from the top of the stator 22 to be positioned outside the fixing ring 27 of the stator 22. Is done. 1, the cooling pipe 28 is opened in the axial direction of the cooling pipe 28 at the upper part of the coil end part 25 and at the upper part of the coil end part 26, as shown in FIG. And an opening 28b. As a result, the cooling oil sent from the cooling oil pump (not shown) to the cooling pipe 28 flows out from the openings 28a and 28b toward the coil end portions 25 and 26.

  In addition, oil guide members 29 and 30 made of resin or the like are attached to the stator 22 so as to cover the upper half of the coil end portions 25 and 26. The oil guide members 29 and 30 have storage portions 29a and 30a (a range indicated by arrows in FIG. 2) formed so as to be able to store cooling oil to some extent, and cooling oil is supplied to the coil end portions 25 and 26. Each includes guiding portions 29b and 30b for guiding to the lower half side. The reservoirs 29a and 30a are provided with dripping holes (not shown) for dripping cooling oil onto the coil end portions 25 and 26 at predetermined intervals. Further, the oil guide member 30 on the coil end portion 26 side includes an oil receiving portion 32 located in the vicinity of the opening 28 b of the cooling pipe 28. As shown in FIG. 3, the oil receiving portion 32 includes an outflow regulating wall 32a for restricting cooling oil from the opening 28b of the cooling pipe 28 from flowing out beyond the coil end portion 26, and a lower portion of the opening 28b. The bottom portion 32b is positioned, and is formed integrally with the storage portion 30a and the guide portion 30b. As shown in FIGS. 1 and 2, the outflow restricting wall 32a and the bottom 32b, that is, the oil receiving portion 32 extends from the vicinity of the opening 28b of the cooling pipe 28 to the vicinity of the top of the stator 22 and the coil end near the top. It is formed so that the cooling oil can be dropped onto the portion 26 and the cooling oil can be introduced into the storage portion 30a.

  The fixing ring 27 for fixing the plurality of divided cores 23a constituting the stator 22 includes an outflow regulating wall 32a constituting the oil receiving portion 32 of the oil guide member 30 in the vicinity of the opening 28b of the cooling pipe 28. An inflow regulating wall 27b is formed so as to face each other. In the embodiment, the inflow restricting wall 27b is extended from the tubular portion 27a by bending one end of the tubular portion 27a by drawing or the like when the fixing ring 27 is manufactured. Further, as shown in FIG. 3, the oil guide member 30 described above is attached to the stator 22 so that the end surface of the bottom portion 32b of the oil receiving portion 32 comes into contact with the inflow restricting wall 27b.

  A vehicle equipped with the motor unit 10 configured as described above generates a magnetic field by passing a current through the stator coil 24 of the motor 20 to rotate the rotor 21 and transmit the rotational torque to the vehicle drive system. Travel by. Accordingly, Joule heat is generated when a current flows through the stator coil 24, and the stator coil 24 generates heat. Therefore, in a vehicle equipped with the motor unit 10, the cooling oil pump is driven when a predetermined condition is satisfied, and the cooling oil supplied from the cooling oil pump to the cooling pipe 28 is supplied from the openings 28 a and 28 b of the cooling pipe 28. It flows out toward the coil end portions 25 and 26.

  The cooling oil that has flowed out of the opening 28 a of the cooling pipe 28 is dropped directly on the coil end portion 25 or is dropped on the coil end portion 25 via the oil guide member 29. That is, the cooling oil that has flowed out of the opening 28a into the oil guide member 29 is temporarily stored in the storage portion 29a and then dropped into the upper region of the coil end portion 25 through the dropping hole. As a result, the cooling oil can be evenly distributed to the upper half side of the coil end portion 25. A part of the cooling oil is further guided from the storage portion 29a to the guide portion 29b, and then guided from the guide portion 29b to the lower half side of the coil end portion 25 by surface tension. As a result, the cooling oil can be spread over the lower half region of the coil end portion 25.

  Further, as can be seen from FIGS. 1 and 3, the cooling oil flowing out from the opening 28 b is restricted from flowing out beyond the coil end portion 26 by the outflow regulating wall 32 a, and the cylindrical portion of the fixing ring 27. The inflow restricting wall 27b extending from 27a restricts the inflow to the outer peripheral surface of the cylindrical portion 27a. Further, as can be seen from FIG. 2, the cooling oil flowing out from the opening 28 b and received by the oil receiving portion 32 is guided to the vicinity of the top of the stator 22 by the oil receiving portion 32 and then directly to the coil end portion 26. It is dropped or dropped onto the coil end portion 26 via the oil guide member 30. The cooling oil guided from the opening 28b to the oil guide member 30 is dropped onto the coil end portion 26 through the storage portion 30a and the guide portion 30b, similarly to the oil guide member 29 side. Thus, the cooling oil flows into the coil end portions 25 and 26 to cool the coil end portions 25 and 26, whereby the entire stator coil 24 is cooled.

  As described above, in the motor unit 10 having the cooling structure of the motor 20 of the embodiment described above, the cooling pipe 28 having the openings 28 a and 28 b positioned above the coil end portions 25 and 26 of the stator coil 24 is the central axis of the rotor 21. Is disposed outside the fixing ring 27 so as to be substantially parallel to the outer ring. And from the cylindrical part 27a of the fixing ring 27 of the stator 22, the inflow restricting wall 27b that restricts the cooling oil flowing out from the opening part 28b of the cooling pipe 28 from flowing into the outer peripheral surface of the cylindrical part 27a is a cooling pipe. 28 extends in the vicinity of the opening 28b. As a result, the cooling oil can be introduced into the coil end portion 26 without flowing into the outer peripheral surface of the cylindrical portion 27a of the fixing ring 27. Therefore, the amount of refrigerant necessary for cooling the stator coil 24 is ensured and the motor is secured. It becomes possible to cool 20 better.

  The motor unit 10 of the embodiment is positioned near the opening 28b of the cooling pipe 28 so as to face the inflow regulating wall 27b, and the outflow regulating wall that regulates the cooling oil from flowing out beyond the coil end portion 26. 32a. Thus, since the cooling oil can be introduced into the coil end portion 26 while restricting the flow of the cooling oil beyond the coil end portion 26, the amount of cooling oil necessary for cooling the stator coil 24 is ensured and the motor 20. Can be cooled more satisfactorily. When the inner wall of the casing (not shown) is opposed to the inflow restricting wall 27b of the fixing ring 27 in the state of being close to the coil end portion 26, the outflow restricting wall 32a is omitted and the cooling oil is cooled by the inner wall of the casing. May flow out beyond the coil end portion 26.

  Further, in the motor unit 10, the cooling pipe 28 is arranged offset from the top of the stator 22, so that the height of the motor unit 10 is higher than when the cooling pipe 28 is arranged near the top of the stator 22. It is possible to suppress an increase in dimension in the vertical direction. The motor unit 10 includes the outflow regulating wall 32a and is positioned near the opening 28b of the cooling pipe 28. The motor unit 10 receives the cooling oil flowing out from the cooling pipe 28 and passes the received cooling oil to the coil end portion 26. The oil receiving section 32 has a dripping oil receiving section 32 that receives the cooling oil flowing out from the cooling pipe 28, guides the received cooling oil to the vicinity of the top of the stator 22, and leads to the coil end section 26. Dripping. As a result, even if the cooling pipe 28 is offset from the top of the stator 22, the cooling oil can be dropped from the vicinity of the top of the stator coil 24 to the coil end portion 26, so that the refrigerant is fed to the entire stator coil 24. Therefore, the motor 20 can be cooled more satisfactorily.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor 20 is equivalent to “electric motor”, the split core 23 a is equivalent to “split core”, the fixing ring 27 is equivalent to “fixing member”, and the cylindrical portion 27 a of the fixing ring 27 is “cylindrical”. The coil end portions 25 and 26 are equivalent to the “coil end portion”, the stator coil 24 is equivalent to the “stator coil”, the stator 22 is equivalent to the “stator”, and the rotor 21 is “rotor”. The opening 28b is equivalent to the “opening”, the cooling pipe 28 is equivalent to the “refrigerant passage”, the inflow restriction wall 27b is equivalent to the “inflow restriction wall”, and the outflow restriction wall 32a is equivalent to the “outflow restriction”. The oil receiving portion 32 constituted by the outflow regulating wall 32a and the bottom portion 32b is equivalent to the “refrigerant receiving portion”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a manufacturing industry of a unit having an electric motor and its cooling structure and a vehicle equipped with the unit.

  DESCRIPTION OF SYMBOLS 10 Motor unit, 20 Motor, 21 Rotor, 22 Stator, 23a Division | segmentation core, 23 Stator core, 24 Stator coil, 25, 26 Coil end part, 27 Fixing ring, 27a Cylindrical part, 27b Inflow control wall, 28 Cooling pipe, 28a 28b Opening part, 29, 30 Oil guide member, 29a, 30a Reserving part, 29b, 30b Guide part, 32 Oil receiving part, 32a Outflow regulating wall, 32b Bottom part.

Claims (4)

A plurality of divided cores arranged in an annular shape, a fixing member having a cylindrical portion for fixing the plurality of divided cores, and a winding wound around each of the plurality of divided cores Cooling structure for an electric motor comprising a stator including a stator coil having a coil end portion protruding from both sides of the cylindrical portion without being covered by the cylindrical portion of the fixing member, and a rotor disposed in the stator In
An opening that is disposed outside the fixed member so as to be substantially parallel to the central axis of the rotor, is connected to a coolant supply source for cooling the electric motor, and is located above one of the coil end portions A refrigerant passage having a portion,
The fixing member extends from the tubular portion to the vicinity of the opening of the refrigerant passage, and restricts the refrigerant flowing out of the opening from flowing into the outer peripheral surface of the tubular portion. An electric motor cooling structure characterized by comprising: In the cooling structure of the electric motor according to claim 1,
A cooling structure for an electric motor, further comprising an outflow restriction wall that is positioned in the vicinity of the opening of the refrigerant passage so as to face the inflow restriction wall and restricts the refrigerant from flowing out beyond the coil end portion. In the cooling structure of the electric motor according to claim 2,
A refrigerant receiving portion that includes the outflow regulating wall and is positioned near the opening of the refrigerant passage, receives the refrigerant flowing out from the opening, and drops the received refrigerant onto the coil end portion. Electric motor cooling structure. In the cooling structure of the electric motor according to claim 3,
The refrigerant passage is arranged offset from the top of the stator,
The cooling structure for an electric motor, wherein the refrigerant receiving portion receives the refrigerant flowing out from the opening portion of the refrigerant passage, guides the received refrigerant to the vicinity of the top portion, and drops the refrigerant to the coil end portion.

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