JPWO2012101813A1 - Motor cooling device - Google Patents

Abstract

Provided is a motor cooling device capable of increasing a cooling amount of a coil end portion of a motor. A stator 3 having a stator core 6 fixed to the case 2 and a coil 7 having a wire wound around a winding portion 6 a protruding to the inner peripheral side of the stator core 6, and disposed on the inner peripheral side of the stator 3 In the cooling device for the motor 5 including the rotor 4, a covering portion 13 in which at least a part of the coil 7 projecting in the axial direction from the stator core 6 is covered with a resin 13 a and a predetermined gap is provided in the covering portion 13. And the cover portion 12 covering the covering portion 13, and the predetermined gap is a flow path 11 through which oil for cooling the coil 7 flows.

Description

  The present invention relates to an apparatus for cooling a motor, and more particularly to an apparatus for cooling a coil end portion protruding in an axial direction of a stator provided in the motor.

  Motors that can output high torque are used for drive systems such as hybrid vehicles and electric vehicles. On the other hand, a motor mounted on a vehicle has a large output torque, but generates a large amount of heat. In particular, since the amount of heat generated at the coil end portion of the motor increases, various devices for cooling the coil end portion of the motor have been developed.

  As an example, an annular cooling oil passage that covers the coil end portion is formed by a motor case, a stator core, and a cylindrical member that is formed in the axial direction of the case, and the cooling oil is lubricated in the cooling oil passage to thereby end the coil end. Japanese Patent Application Laid-Open Nos. 2004-23805 and 2003-289650 describe devices for cooling the unit. Moreover, the apparatus described in Unexamined-Japanese-Patent No. 2004-23805 has integrally formed the resin plate in the both end surfaces in the axial direction of a stator core.

Furthermore, Japanese Patent Application Laid-Open No. 2004-120923 describes an apparatus configured to cover a coil end portion with a resin mold by filling a gap between the coil end portion and the case with resin. The device described in Japanese Patent Application Laid-Open No. 2004-120923 is provided with a cylindrical wall surface with a gap inside the outer wall forming the appearance of the case, and cooling water is provided between the outer wall and the cylindrical wall surface. By making it flow, it is comprised so that a stator and a coil end part may be cooled.

  As described above, in the apparatuses described in Japanese Patent Application Laid-Open Nos. 2004-23805 and 2003-289650, an annular cooling oil passage that covers the coil end portion is formed, and the cooling oil is supplied to the cooling oil passage. As a result, the coil at the coil end portion and the cooling oil are in direct contact with each other, so that the coil cooling efficiency can be improved as compared with the case where the coil end portion is covered with resin. However, when the amount of cooling oil for cooling the coil end portion is small, or a so-called mechanical oil pump that drives the oil pump using the power of the motor is used, and the rotational speed of the motor is low. In some cases, the cooling amount of the coil end portion may decrease.

The present invention has been made paying attention to the above technical problem, and an object of the present invention is to provide a motor cooling device capable of increasing the cooling amount of the coil end portion of the motor.

  In order to achieve the above object, the present invention provides a stator having a stator core fixed to a case, a coil having a wire wound around a winding portion protruding toward the inner peripheral side of the stator core, and an inner portion of the stator. In a motor cooling device including a rotor disposed on a circumferential side, a covering portion in which at least a part of a coil protruding in an axial direction from the stator core is covered with a resin, and a predetermined gap is provided in the covering portion. And a cover portion covering the covering portion, wherein the predetermined gap is a flow path through which oil for cooling the coil flows.

  Moreover, this invention is comprised in the said invention so that the said coating | coated part may cover a part of said coil and the said stator core in the state which exposed at least one part of the said coil to the said flow path. This is a motor cooling device.

  Further, according to the present invention, in the above invention, the covering portion is formed by bending the element wire at a position protruding in an axial direction of the stator core, and the resin is interposed between the bent element wire and an end surface of the stator core. The motor cooling device is configured to cover a part of the coil and the stator core in a state in which is satisfied.

  Furthermore, this invention is the motor cooling device according to any one of the above inventions, wherein an end surface of the covering portion is formed in parallel with an inner surface of the cover portion facing the end surface. .

  Furthermore, the present invention is characterized in that, in any one of the above inventions, a seal member provided between the outer peripheral side of the covering portion protruding in the axial direction from the stator core and the cover portion is provided. This is a motor cooling device.

  And this invention is characterized in that, in any one of the above inventions, said strand includes a flat wire formed so that a cross section is rectangular, and an end surface of said flat wire is formed flat. This is a motor cooling device.

  According to this invention, the covering portion that covers at least a part of the coil protruding in the axial direction from the stator core by filling the resin with the resin, and the cover portion that covers the covering portion with a predetermined gap therebetween is provided. Since the predetermined gap is a flow path through which oil for cooling the coil flows, the coil wound around the stator core can be cooled by the oil. Moreover, since the flow velocity of the oil flowing through the flow path can be increased by reducing the cross-sectional area of the flow path, the apparent thermal resistance between the coil and the oil can be reduced, and the cooling amount of the coil can be reduced. Can be increased.

  According to the present invention, the covering portion is configured to cover a part of the coil and the stator core in a state where at least a part of the coil is exposed to the flow path, so that the exposed coil is directly cooled by the oil. The amount of cooling of the coil can be improved.

  According to the present invention, the covering portion is formed by bending the element wire at a position protruding in the axial direction of the stator core, and filling the resin between the bent element wire and the end surface of the stator core. Since it is comprised so that a stator core may be covered, generation | occurrence | production of the flow resistance and turbulent flow by the oil which flows through a flow path flowing between a stator core and the bent strand can be suppressed or prevented. As a result, a decrease in the oil flow rate can be suppressed or prevented, and a decrease in the cooling amount of the coil can be suppressed or prevented.

  Further, according to the present invention, since the end surface of the covering portion is formed in parallel with the inner surface of the cover portion facing the end surface, the cross-sectional area of the flow path formed by the covering portion and the cover portion is constant. can do. Therefore, the flow resistance of the oil flowing through the flow path can be reduced, and the decrease in the cooling amount of the coil can be suppressed or prevented.

  Furthermore, according to the present invention, since the sealing material is provided between the outer peripheral side of the covering portion protruding in the axial direction from the stator core and the cover portion, it is possible to suppress or prevent oil leakage. . Therefore, it is possible to suppress or prevent a decrease in the flow rate due to oil leakage, and it is possible to suppress or prevent a decrease in the cooling amount of the coil.

  According to the present invention, the element wire includes a flat wire having a rectangular cross section, and the end surface of the flat wire is formed flat, so that the oil flows on the end surface of the flat wire. The resistance can be reduced, and as a result, a decrease in the cooling amount of the coil can be suppressed or prevented.

It is sectional drawing for demonstrating the structural example of the motor which concerns on this invention. It is a perspective view for demonstrating the structure of the stator provided in the motor. It is a figure for demonstrating the filling state of resin. It is a figure which shows another filling state. It is a figure which shows another filling state.

  Next, the present invention will be specifically described. A motor that can be an object of the present invention generates heat when energized. For example, a motor (motor / generator) mounted on an industrial machine or a hybrid vehicle, or an in-wheel provided for each wheel. Various conventionally known motors such as motors can be mentioned. FIG. 1 shows a cross section of an in-wheel motor 1. As shown in the figure, a motor 5 composed of a stator 3 and a rotor 4 is provided inside a motor housing 2.

  The stator 3 includes a stator core 6 formed integrally with the motor housing 2 and a coil 7 formed by winding a wire around the stator core 6. Specifically, the stator core 6 is configured by laminating electromagnetic steel plates in the axial direction, and has a plurality of winding portions 6a that protrude to the inner peripheral side and that are formed at intervals in the circumferential direction. A coil 7 having a rectangular cross section is wound around the portion 6a. As shown in FIG. 2, the coil 7 is disposed along the axial direction of the stator core 6 on the side surface of the winding portion 6 a, and is bent at a position protruding in the axial direction of the stator core 6, so as to extend in the circumferential direction of the stator core 6. Along the end surface of the stator core 6. Further, the rectangular wires arranged on the side surface and the end surface of the stator core 6 are arranged continuously in the radial direction.

  The rotor 4 disposed on the inner peripheral side of the stator 6 is configured by laminating electromagnetic steel plates in the axial direction in the same manner as the stator core 6, and is formed integrally with the output shaft 8. Further, a permanent magnet is attached to the outer peripheral side of the rotor 4.

  Accordingly, when the coil 7 wound around the stator core 6 is energized, an electromagnetic force corresponding to the electric power is generated. Therefore, the electromagnetic force and the magnetic force of the permanent magnet attached to the rotor 4 attract or repel each other. Torque is obtained.

  On the other hand, in the in-wheel motor 1, when a high torque is required such as when the vehicle is traveling on a steeply uphill road, the power supplied to the coil 7 increases, so the amount of heat generated by the coil 7 increases due to copper loss. To do. The in-wheel motor 1 is mounted inside the wheel, and an oil pump 10 that pressurizes and discharges oil used for cooling the motor 5 and lubricating the gear train portion 9 and the like is also mounted inside the wheel. Since it is configured, the mounting space is limited. For this reason, a so-called mechanical oil pump in which the oil pump 10 is driven by the power of the motor 5 is used. Therefore, when the vehicle is traveling at a low speed, the amount of oil discharged from the oil pump 10 is reduced.

  Therefore, the cooling device for the motor 5 according to the present invention is configured to cool the motor 5 with a small amount of oil. That is, the flow rate of the oil for cooling the motor 5 is secured to increase the flow rate of the oil, and the apparent thermal resistance between the oil and the cooling part of the motor 5 is reduced. Yes. FIG. 1 is a diagram for explaining an example of the configuration, and a flow path 11 for cooling a portion protruding in the axial direction from the stator core 6 (hereinafter referred to as a coil end portion 7a) is formed.

  The configuration of the flow path 11 will be specifically described. A coil end cover portion 12 is provided on the outer peripheral side of the motor housing 2 so as to cover the coil end portion 7a. The coil end cover portion 12 has an outer peripheral wall 12a projecting in the axial direction from the motor housing 2 with a gap on the outer peripheral side of the coil end portion 7a in the radial direction of the motor 5, and an inner peripheral side of the coil end portion 7a. An inner peripheral wall 12b that protrudes in the axial direction from the motor housing 2 with a gap is provided, and is formed in an annular shape so as to collectively cover the plurality of coil end portions 7a.

  Further, a resin 13 a for fixing the coil 7 to the stator core 6 is filled on the stator core 6 side of the coil end portion 7 a in the axial direction. That is, the resin mold 13 is formed by filling the resin 13a between the coil end portions 7a protruding at both ends of the stator core 6 in the axial direction. A resin mold 13 is also formed between the winding portions 6a in the circumferential direction. Therefore, a cylindrical resin mold 13 is formed, and a part of the coil end portion 7a protrudes from the resin mold 13, and an O-ring or the like is formed in the gap between the resin mold 13 and the outer peripheral wall 12a and the inner peripheral wall 12b. The sealing material 14 is provided.

  As described above, the coil end portion 7 a is disposed so as to protrude into the annular gap formed by the coil end cover portion 12, the motor housing 2, and the resin mold 13. Therefore, the oil is lubricated by using the gap as the flow path 11 so that the coil end portion 7a and the oil are in direct contact with each other to cool the coil end portion 7a. In addition, since the flow rate of the oil flowing through the flow channel 11 can be maintained by forming the flow channel 11, that is, the flow rate can be prevented from decreasing due to the oil flowing out to the outside. By making the cross-sectional area small, the flow velocity can be improved, and as a result, the cooling amount of the coil end portion 7a can be increased. Furthermore, by forming the end surface of the resin mold 13 in parallel with the inner wall surface of the motor housing 2 facing the end surface, the flow resistance of the oil flowing through the flow path 11 can be further reduced.

  In order to reduce the flow resistance of oil, the cooling device for the motor 5 according to the present invention includes an end face in the axial direction of the stator core 6 and a coil disposed along the end face of the stator core 6 as shown in FIG. 7 is filled with a resin 13a. That is, since the coil 7 is bent at a position protruding in the axial direction of the stator core 6, there is a possibility that there is not a small gap between the end surface of the stator core 6 and the bent coil 7, so that the gap is filled. Resin 13a is filled. 3A is an enlarged view of arrow a in FIG. 2, and FIG. 3B is an enlarged view of arrow b in FIG. By filling the resin 13a in this way, the flow resistance caused by the oil flowing through the flow path 11 flowing into the gap between the coil 7 and the resin 13a can be reduced, or the turbulent flow can be suppressed or prevented. Therefore, the flow rate of oil can be maintained, and as a result, a decrease in the cooling amount of the coil end portion 7a can be suppressed or prevented. Moreover, since the flat wire is continuously arranged in the radial direction as described above, the end surface thereof becomes flat, and the flow resistance can be further reduced.

  In the motor cooling device according to the present invention, the coil end portion 7a can be cooled by direct contact between the coil end portion 7a and the oil, and the coil end portion 7a and the stator core 6 are filled with resin. 4 and 5, the end of the resin mold 13 may be extended to the center of the bent rectangular wire in the thickness direction, or up to the end of the bent rectangular wire, that is, the coil end. It is good also as a location where the edge part of the part 7a and the end surface of the resin mold 13 become the same position in an axial direction.

  Here, an oil lubrication path for lubricating oil to the motor 5 shown in FIG. 1 will be described. As described above, the in-wheel motor 1 is mounted with the oil pump 10 that is driven by the power of the motor 5 because the mounting space is limited. A part of the oil discharged from the oil pump 10 is supplied for lubrication of the other gear train portion 9 and the like, and the other oil is supplied to the right channel 11a shown in the drawing. And the oil which flowed through the annular flow path 11a is supplied to the left flow path 11b shown in the figure. That is, the flow path 11a includes a supply port to which oil is supplied from the oil pump 10 and a discharge port in the vicinity of the supply port, and a shielding plate that shields the flow path 11a is provided between the supply port and the discharge port. . With such a configuration, the oil supplied to the flow path 11a flows in one direction, and as a result, the flow velocity can be improved. The left channel 11b shown in the figure similarly includes a supply port and a discharge port, and a shielding wall is provided between the supply port and the discharge port.

  Then, the oil that has flowed through the left flow path 11b shown in the figure flows through the gap between the outer peripheral surface of the stator 6 and the inner wall surface of the motor housing 2, and is discharged to the oil pan 15. Since the stator 6 is assembled to the motor housing 2, a gap due to a dimensional error or a margin for assembly is formed at least on the outer peripheral surface of the stator 6 and the inner wall surface of the motor housing 2. Therefore, by flowing the oil that has cooled the coil end portion 7 a into the gap between the stator 6 and the motor housing 2, air intervening in the gap between the stator 6 and the motor housing 2 can be discharged. Cooling efficiency can be improved.

  Note that the present invention can be directed to the motor 5 that generates heat when energized, and thus may be a conventionally known synchronous motor or induction motor. Further, it is sufficient that the flow rate of oil is increased or the flow resistance is lowered in order to cool the coil end portion 7a, and the end surface of the resin mold 13 may be formed flat, or oil A groove may be formed along the flow direction.

[0002]
In the apparatus described in the 89650 publication, an annular cooling oil passage that covers the coil end portion is formed, and the cooling oil is allowed to flow through the cooling oil passage so that the coil at the coil end portion and the cooling oil are in direct contact with each other. The coil cooling efficiency can be improved as compared with the case where the coil end portion is covered with resin. However, when the amount of cooling oil for cooling the coil end portion is small, or a so-called mechanical oil pump that drives the oil pump using the power of the motor is used, and the rotational speed of the motor is low. In some cases, the cooling amount of the coil end portion may decrease.
SUMMARY OF THE INVENTION [0006]
The present invention has been made paying attention to the above technical problem, and an object of the present invention is to provide a motor cooling device capable of increasing the cooling amount of the coil end portion of the motor.
[0007]
In order to achieve the above object, the present invention provides a stator having a stator core fixed to a case, a coil having a wire wound around a winding portion protruding toward the inner peripheral side of the stator core, and an inner portion of the stator. In a motor cooling device including a rotor disposed on a circumferential side, a covering portion in which at least a part of a coil protruding in an axial direction from the stator core is covered with a resin, and a predetermined gap is provided in the covering portion. A cover portion covering the covering portion, wherein the predetermined gap is a flow path in which oil for cooling the coil flows in a circumferential direction, and the element wire is an end portion in the axial direction of the stator core. Is wound in a state of being laminated in the radial direction of the stator core and in the radial direction of the stator core.
[0008]
Moreover, this invention is comprised in the said invention so that the said coating | coated part may cover a part of said coil and the said stator core in the state which exposed at least one part of the said coil to the said flow path. This is a motor cooling device.
[0009]
Further, according to the present invention, in the above invention, the covering portion is formed by bending the element wire at a position protruding in an axial direction of the stator core, and the resin is interposed between the bent element wire and an end surface of the stator core. Is configured to cover a part of the coil and the stator core in a state where

[0003]
This is a motor cooling device.
[0010]
Furthermore, this invention is the motor cooling device according to any one of the above inventions, wherein an end surface of the covering portion is formed in parallel with an inner surface of the cover portion facing the end surface. .
[0011]
Furthermore, the present invention is characterized in that, in any one of the above inventions, a seal member provided between the outer peripheral side of the covering portion protruding in the axial direction from the stator core and the cover portion is provided. This is a motor cooling device.
[0012]
Furthermore, this invention is characterized in that, in any one of the above inventions, the strand includes a flat wire formed so that a cross section is rectangular, and an end surface of the flat wire is formed flat. This is a motor cooling device.
According to the present invention, in any one of the above inventions, the flow path is formed in an annular shape, the supply port for supplying oil to the flow path, the vicinity of the supply port, and the annular shape The flow direction of the oil flowing through the flow path is made one direction by shielding the flow path between the discharge port for discharging the oil flowing through the flow channel to the outside and the supply port and the discharge port. The motor cooling device further includes a shielding plate formed as described above.
[0013]
According to this invention, the covering portion that covers at least a part of the coil protruding in the axial direction from the stator core by filling the resin with the resin, and the cover portion that covers the covering portion with a predetermined gap therebetween is provided. Since the predetermined gap is a flow path through which oil for cooling the coil flows, the coil wound around the stator core can be cooled by the oil. Moreover, since the flow velocity of the oil flowing through the flow path can be increased by reducing the cross-sectional area of the flow path, the apparent thermal resistance between the coil and the oil can be reduced, and the cooling amount of the coil can be reduced. Can be increased.
[0014]
According to the present invention, the covering portion is configured to cover a part of the coil and the stator core in a state where at least a part of the coil is exposed to the flow path, so that the exposed coil is directly cooled by the oil. The amount of cooling of the coil can be improved.
[0015]
According to the present invention, the covering portion is formed by bending the element wire at a position protruding in the axial direction of the stator core, and filling the resin between the bent element wire and the end surface of the stator core. Since it is comprised so that a stator core may be covered, generation | occurrence | production of the flow resistance and turbulent flow by the oil which flows through a flow path flowing between a stator core and the bent strand can be suppressed or prevented. As a result, to suppress or prevent a decrease in oil flow rate

Claims (6)

A motor comprising: a stator having a stator core fixed to a case; a coil having a wire wound around a winding portion protruding toward the inner peripheral side of the stator core; and a rotor disposed on the inner peripheral side of the stator In the cooling device,
A covering portion in which at least a part of the coil protruding in the axial direction from the stator core is covered with a resin;
A cover part covering the covering part with a predetermined gap in the covering part,
The motor cooling device, wherein the predetermined gap is a flow path through which oil for cooling the coil flows.   The said coating | coated part is comprised so that a part of said coil and the said stator core may be covered in the state which exposed at least one part of the said coil to the said flow path. Motor cooling device.   The covering portion is formed by bending the element wire at a position protruding in the axial direction of the stator core, and filling the resin between the bent element wire and the end surface of the stator core. The motor cooling device according to claim 2, wherein the motor cooling device is configured to cover the stator core.   The motor cooling device according to any one of claims 1 to 3, wherein an end surface of the covering portion is formed in parallel with an inner surface of the cover portion facing the end surface.   5. The motor cooling according to claim 1, further comprising: a sealing material provided between an outer peripheral side of a covering portion protruding in an axial direction from the stator core and the cover portion. apparatus. The strand includes a rectangular wire formed so that a cross section is rectangular,
6. The motor cooling device according to claim 2, wherein an end surface of the flat wire is formed flat.

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