JP4935839B2 - Motor housing structure - Google Patents

Description

  The present invention relates to a motor housing structure, and more particularly to a motor housing structure in which a cooling medium flow path is formed inside the housing.

  Travel drive motors used in electric vehicles, hybrid vehicles, etc. need to be mounted in a limited space in the vehicle, so miniaturization is required, and higher output is required to obtain higher power performance. Is also sought. For this reason, the output per volume of the motor will be improved. However, since it is necessary to cool the heat generation that increases as the output increases with a small heat dissipation area, a water cooling method with high cooling efficiency is used for cooling the motor. It is generally used (for example, Patent Document 1).

  In the motor of Patent Document 1, a cooling water passage for circulating cooling water is formed inside a motor housing containing motor components such as a rotor and a stator around which a coil is wound, and cooling water is supplied to the cooling water passage. In this configuration, the motor is cooled by removing heat generated from a coil or the like when the motor is driven.

JP 2004-140881 A

  By the way, other parts are also arranged in the vicinity of the outer peripheral surface of the motor mounted in the vehicle, and along the circumferential direction in the motor housing due to restrictions on the layout of the cooling water circulation piping in the vehicle. The range of the cooling water channel formed in this way may be limited. For this reason, the motor housing includes a region where the arc-shaped cooling water channel exists along the circumferential direction of the motor housing and a large region where the cooling water channel does not exist.

  For this reason, there is a difference in the thickness of the motor housing between the region where the cooling water channel exists in the circumferential direction of the motor housing and the region where the cooling water channel does not exist, and the rigidity of the motor housing in the circumferential direction becomes uneven. End up.

  As a result, when the stator is shrink fitted on the inner peripheral surface of the motor housing and contracted and tightened, the rigidity of the motor housing is biased, so there is a place where stress is partially concentrated on the motor housing. The internally generated stress is significantly higher than other parts. Therefore, when the stator is shrink-fitted and shrink-fitted on the inner peripheral surface of the motor housing, the motor housing is protected from damage or the like even if high stresses are concentrated on the motor housing. Must be formed of an expensive material having high strength.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides a motor housing structure capable of reducing a rigidity imbalance due to uneven thickness between a portion having a cooling water passage and a portion having no cooling water passage formed therein. For the purpose.

  In order to achieve the above object, the housing structure of the motor according to the present invention has a cooling medium supply port on one end side or a cooling medium discharge port on the other end side of the cooling medium flow path provided along the circumferential direction inside the housing. From any one of the above, a flow path extension extending along the circumferential direction inside the housing is integrally formed.

  According to the motor housing structure of the present invention, the flow extending along the circumferential direction inside the housing from either the cooling medium supply port on one end of the cooling medium flow path or the cooling medium discharge port on the other end side. By integrally forming the path extension portion, the thickness in the circumferential direction of the housing becomes substantially uniform, so that the rigidity in the circumferential direction of the housing becomes substantially uniform.

  Thus, for example, when the stator is shrink-fitted and contracted and fastened to the inner peripheral surface of the housing, the internally generated stress generated in the housing is substantially uniform in the circumferential direction without high stress being partially concentrated on the housing. And the maximum internally generated stress on the housing is reduced. As a result, the motor housing can be formed of an inexpensive material.

1 is a perspective view showing an external appearance of a motor according to Embodiment 1 of the present invention. 1 is a schematic cross-sectional view showing a motor according to Embodiment 1 of the present invention. 1 is a schematic cross-sectional view showing a housing structure of a motor according to Embodiment 1 of the present invention. (A) is a schematic perspective view which shows the housing structure of the motor which concerns on Embodiment 1, (b) is a perspective view which shows the cooling water channel which formed the water channel extension part integrally. The schematic sectional drawing which shows the housing structure of the motor which concerns on Embodiment 2 of this invention. (A) is a schematic perspective view which shows the housing structure of the motor which concerns on Embodiment 2, (b) is a perspective view which shows the cooling water channel which formed the water channel extension part integrally. The figure which shows the state which installed the motor related components in the motor housing surface to which the housing structure of the motor which concerns on Embodiment 2 is applied. The schematic diagram at the time of casting of the motor housing to which the housing structure of the motor which concerns on Embodiment 1, 2 is applied. The schematic perspective view which shows the housing structure of the motor which concerns on Embodiment 3 of this invention. The schematic perspective view which shows the housing structure of the motor which concerns on Embodiment 4 of this invention.

Hereinafter, the present invention will be described based on the illustrated embodiments.
<Embodiment 1>
1 is a perspective view showing an external appearance of a motor according to Embodiment 1 of the present invention, FIG. 2 is a schematic sectional view showing the motor according to this embodiment, and FIG. 3 shows a housing structure of the motor according to this embodiment. 4A is a schematic perspective view showing a housing structure of the motor according to the present embodiment, and FIG. 4B is a perspective view showing a cooling water channel in which a water channel extension is integrally formed. .

  As shown in FIGS. 1 and 2, a stator (stator) 4 around which a coil 3 is wound and a rotor (rotor) are disposed inside a cylindrical motor housing 2 that is a frame of the motor 1 of the present embodiment. ) A motor shaft 6 and the like in which 5 is fitted to the peripheral surface are installed. The motor 1 is, for example, a travel drive motor installed in a drive system of an electric vehicle or a hybrid vehicle, and is driven and controlled via an inverter by receiving power supply from a battery (for example, a lithium ion battery).

  As shown in FIGS. 2, 3, 4 (a), and (b), the motor housing 2 has an arc shape for flowing cooling water (cooling medium) along the circumferential direction of the motor housing 2. The cooling water channel 7 is formed. A cooling water supply port 8 is provided on one end side of the cooling water channel 7, and a cooling water drain port 9 is provided on the other end side of the cooling water channel 7. In the present embodiment, the cooling water passage 7 is formed in a range of about 60% of the entire circumference of the motor housing 2 due to restrictions on the layout of the cooling water circulation piping in the vehicle. The cooling water supply port 8 on one end side of the cooling water channel 7 is arranged obliquely below the motor housing 2, and the cooling water drain port 9 on the other end side of the cooling water channel 7 is obliquely above the motor housing 2. Has been placed.

  During the cooling operation of the motor 1, the cooling water is supplied from the cooling water supply port 8 to the cooling water passage 7 inside the motor housing 2 through the cooling water circulation pipe 10 a by the operation of a pump (not shown) and flows in the cooling water passage 7. The cooling water absorbs heat generated from the coil 3 or the like wound around the stator 4 installed inside the motor housing 2 when the motor 1 is driven. The cooling water that has absorbed heat is discharged from the cooling water drain port 9 and is cooled by heat exchange with outside air by a heat exchanger (not shown) provided in the middle of the cooling water circulation pipe 10b. The cooled cooling water is circulated and supplied again from the cooling water supply port 8 into the cooling water channel 7 through the cooling water circulation pipe 10a. Thus, the motor 1 that rises in temperature due to heat generated when the motor is driven can be cooled by the cooling water flowing through the cooling water passage 7 inside the motor housing 2.

  In this embodiment, as shown in FIGS. 2 and 3, inside the motor housing 2, in the circumferential direction (counterclockwise direction) from the cooling water supply port 8 of the cooling water passage 7 to the cooling water drain port 9 side. An arc-shaped waterway extension 7a (portion shown by a mesh) is integrally formed. The closed tip of the water channel extension 7 a is located near the front of the cooling water drain 9 in the motor housing 2. In addition, although the base end side of the water channel extension part 7a is integrally formed so as to communicate with the cooling water channel 7, in order to distinguish the cooling water channel 7 part and the water channel extension part 7a part, A mesh is provided in the portion (the same applies to the following embodiments).

  The water channel extension 7a extending from the cooling water supply port 8 of the cooling water channel 7 to the cooling water drain port 9 side is not for flowing cooling water, but has a thickness in the circumferential direction of the motor housing 2 on the side of the water channel extension 7a. It is for making it the same as the cooling water channel 4 side. That is, in the conventional motor housing structure, the range of the cooling water passage formed along the circumferential direction inside the motor housing is limited due to restrictions on the layout of the cooling water circulation piping in the vehicle. The thickness of the region where the cooling water channel is formed and the other region (the region where the cooling water channel is not formed) are greatly different, and the rigidity of the motor housing in the circumferential direction is non-uniform.

  As described above, the water channel extension 7a is formed in the motor housing 2 so as to extend from the cooling water supply port 8 of the cooling water channel 7 to the vicinity of the cooling water drain port 9 in the counterclockwise direction (counterclockwise direction). Since the thickness of the motor housing 2 in the circumferential direction becomes substantially uniform, the rigidity of the motor housing 2 in the circumferential direction becomes substantially uniform. As a result, when the stator 4 is shrink-fitted on the inner peripheral surface of the motor housing 2 and contracted and fastened, high stress is not concentrated on the motor housing 2 and the internally generated stress generated in the motor housing 2 is reduced to the circle. It is made substantially uniform in the circumferential direction, and the maximum internally generated stress on the motor housing 2 is reduced.

  As a result, even when the motor housing 2 is formed using a low-strength material when the stator 4 is shrink fitted and contracted to the inner peripheral surface of the motor housing 2, the motor housing 2 may be damaged due to internally generated stress. It is possible to prevent the occurrence. Therefore, an inexpensive material with low strength can be used as the material of the motor housing 2, and the thickness of the entire motor housing 2 can be reduced, so that the material cost can be reduced.

  Further, since an inexpensive material with low strength can be used for the motor housing 2, the stator 4 is shrink-fitted on the inner peripheral surface of the motor housing 2 by shrinkage as compared with the case where the motor housing 2 is formed of a material with high strength. It becomes possible to relax the heat treatment conditions (heating time, heating temperature, etc.) at the time of fastening.

<Embodiment 2>
In this embodiment, as shown in FIGS. 5, 6 (a), (b), inside the motor housing 2, the cooling water from the cooling water outlet 9 of the cooling water passage 7 in the circumferential direction (clockwise direction). An arcuate water channel extension 7a (portion shown by a mesh) that extends toward the supply port 8 is formed integrally. The closed tip of the water channel extension 7 a is located near the front of the cooling water supply port 8 inside the motor housing 2. Other configurations are the same as those of the first embodiment.

  Thus, even when the water channel extension 7a extending from the cooling water drain port 9 of the cooling water channel 7 to the cooling water supply port 8 side is formed, the same effect as that of the first embodiment can be obtained. Furthermore, in this embodiment, as shown in FIG. 5, the closed end side of the water channel extension 7a is located on the lower side (cooling water supply port 8 side) of the motor housing 2, and the cooling water channel 7 of the water channel extension 7a. The base end side communicating with the cooling water drain port 9 is located in the vicinity.

  Accordingly, the residual air heated in the water channel extension 7a due to heat generated by driving the motor is discharged together with the cooling water from the upper cooling water drain 9 without remaining in the water channel extension 7a. As a result, air with low thermal conductivity does not exist in the water channel extension 7a, and a decrease in cooling performance can be suppressed.

  Further, as in the first and second embodiments, the water channel extension 7a is formed in the cooling water supply port 8 or the cooling water drain port 9 of the cooling water channel 7, so that the rigidity of the motor housing 2 in the circumferential direction is substantially uniform. Can be. Thereby, for example, as shown in FIG. 7, the arrangement positions of the cooling water supply port 8 and the cooling water drain port 9 of the cooling water channel 7 are limited depending on the positions of the motor-related parts 11 installed on the surface of the motor housing 2. Even in this case, the rigidity in the circumferential direction of the motor housing 2 can be made substantially uniform by forming the water channel extension 7a so as to extend from the cooling water drain port 9 (or the cooling water supply port 8).

  As a result, the rigidity in the circumferential direction of the motor housing 2 is made substantially uniform regardless of the position of the cooling water passage 7 (the cooling water supply port 8 and the cooling water drain port 9) arranged in the circumferential direction of the motor housing 2. Therefore, the degree of freedom in layout when the motor 1 is mounted on the vehicle is improved, and the motor installation space can be further reduced.

  In the case where the motor housing 2 in which the water channel extension 7a is formed on the cooling water supply port 8 side or the cooling water drain port 9 side of the cooling water channel 7 in the first and second embodiments is manufactured by a casting method, for example, As shown in FIG. 8, the outer end portions of the cores 12 provided on both end surfaces of the adjacent cooling water channel 7 and water channel extension 7a can be held by the core holding member 12a. Reference numerals 13a to 13d are core supports.

  Thus, when manufacturing the motor housing 2 which has the cooling water channel 7 and the water channel extension part 7a in an inside by a casting process, each core provided in the both end surfaces of the adjacent cooling water channel 7 and the water channel extension part 7a at the front end side is provided. By holding the outer end of 12 with the core holding member 12a, the stability when arranging each core 12 is improved, and the shape accuracy of the cooling water channel 7 and the water channel extension 7a can be improved. . Thereby, productivity can be improved by improving the casting yield.

  In addition, since it is not necessary to increase the thickness of the motor housing 2 in consideration of variations when the cores are arranged, the motor housing 2 can be reduced in weight.

<Embodiment 3>
In the present embodiment, as shown in FIG. 9, two cooling water passages 7b and 7c are arranged in the axial direction of the motor housing 2 (motor axial direction), and the respective cooling water passages 7b and 7c are provided via a water passage bent portion 7d. Communicate.

  Each of the cooling water channels 7b and 7c is formed along the circumferential direction inside the motor housing 2 in the same manner as in the first and second embodiments. The cooling water channel 7b has a cooling water supply port 8 provided at the front end side. The water channel extension 7a formed so as to extend from the cooling water supply port 8 toward the water channel bent portion 7d is integrally provided. A cooling water drain port 9 is provided at the tip of the cooling water channel 7c.

  The vicinity of the distal end of the water channel extension 7a and the cooling water drain port 9 face each other so as to be close to the front end side of the water channel bent portion 7d. Further, the vicinity of the tip of the water channel extension 7 a and the cooling water drain port 9 are provided at substantially the same position with respect to the axial direction (motor axial direction) of the motor housing 2.

  In the motor having the motor housing structure of the present embodiment, the cooling water is supplied from the cooling water supply port 8 to the cooling water passage 7b in the motor housing 2 through the cooling water circulation pipe (not shown) by the operation of the pump (not shown). The cooling water supplied to the cooling water channel 7 b flows into the cooling water channel 7 c through the water channel bending portion 7 d and is discharged from the cooling water drain port 9. As described above, the motor that rises in temperature due to the heat generated when the motor is driven can be cooled by the cooling water flowing through the cooling water passage 7b, the water-bending portion 7d, and the cooling water passage 7c inside the motor housing 2.

  Thus, in this embodiment, since a plurality of cooling water channels (in this embodiment, the two cooling water channels 7b and 7c) are provided in the axial direction of the motor housing 2, one wide cooling water channel is provided. Compared with the case where it provides, the channel cross-sectional area per one can be made small. Thereby, the flow velocity of the cooling water flowing through each cooling water channel 7b, 7c is increased, and the cooling capacity can be further increased.

  In the present embodiment, the water channel extension 7a is formed in the motor housing 2 so as to extend from the cooling water supply port 8 of the cooling water channel 7b toward the water channel bent portion 7d in the clockwise direction (clockwise direction). As a result, the thickness of the motor housing 2 in the circumferential direction becomes substantially uniform, so that the rigidity of the motor housing 2 in the circumferential direction becomes substantially uniform. Thereby, even when a plurality of cooling water channels (in this embodiment, two cooling water channels 7b and 7c) are arranged in the axial direction of the motor housing 2, the same effects as those of the first and second embodiments can be obtained. it can.

<Embodiment 4>
In the present embodiment, as shown in FIG. 10, two cooling water passages 7b and 7c are arranged in the axial direction of the motor housing 2 (motor axial direction), and the respective cooling water passages 7b and 7c are provided via the water passage bent portion 7d. Communicate.

  Each of the cooling water channels 7b and 7c is formed along the circumferential direction inside the motor housing 2 in the same manner as in the first and second embodiments, and the cooling water supply port 8 is provided at the tip of the cooling water channel 7b. A cooling water drain port 9 is provided at the tip of 7c. The respective leading end portions of the cooling water passage 7b and the cooling water passage 7c are shifted with respect to the axial direction (motor axial direction) of the motor housing 2 so that the leading end portion of the cooling water passage 7c is positioned on the lower side. Moreover, in this embodiment, the water channel extension part 7a formed so that it may extend in the cooling water drain port 9 side from the water channel bending part 7d of the cooling water channel 7c is provided integrally.

  With such an arrangement configuration of the cooling water channel 7b, the water channel bending portion 7d, the cooling water channel 7c, and the water channel extension portion 7a, the motor housing 2 is arranged in the motor housing 2 with respect to the axial direction of the motor housing 2 (motor axial direction). At least a part of one or more of the cooling water channel 7b, the water channel bending portion 7d, the cooling water channel 7c, and the water channel extension 7a is located in at least a part of the circumferential direction.

  In the motor having the motor housing structure of the present embodiment, the cooling water is supplied from the cooling water supply port 8 to the cooling water passage 7b in the motor housing 2 through the cooling water circulation pipe (not shown) by the operation of the pump (not shown). The cooling water supplied to the cooling water channel 7 b flows into the cooling water channel 7 c through the water channel bending portion 7 d and is discharged from the cooling water drain port 9. As described above, the motor that rises in temperature due to the heat generated when the motor is driven can be cooled by the cooling water flowing through the cooling water passage 7b, the water-bending portion 7d, and the cooling water passage 7c inside the motor housing 2.

  As described above, in the present embodiment as well, as in the third embodiment, a plurality of cooling water passages (in this embodiment, two cooling water passages 7b and 7c) are provided in the axial direction of the motor housing 2. You can increase your ability.

  In the present embodiment, the water channel extension 7a is formed in the motor housing 2 so as to extend from the water channel bent portion 7d of the cooling water channel 7c toward the cooling water drain port 9 in the clockwise direction (clockwise direction). Yes. Further, at least a part of the motor housing 2 in the circumferential direction with respect to the axial direction of the motor housing 2 (motor axial direction) inside the motor housing 2 includes a cooling water channel 7b, a water channel bending portion 7d, a cooling water channel 7c, and a water channel. Since any one or more of the extension portions 7a are located, it is possible to improve the uniformity of the thickness in the axial direction of the motor housing 2 (motor axial direction). Thereby, the uniformity of the rigidity with respect to the axial direction (motor shaft direction) of the motor housing 2 can be further increased.

  In the third and fourth embodiments, the two cooling water channels are arranged in the axial direction (motor axial direction) of the motor housing 2, but three or more depending on the length of the motor housing 2 in the axial direction. The cooling water channel may be arranged.

  In each of the above embodiments, the example of the motor housing structure in the travel drive motor installed in the drive system of the electric vehicle or the hybrid vehicle has been described. However, in addition to this, the cooling water is formed in the cooling water passage formed inside the motor housing. Similarly, the present invention can be applied to an electric motor configured to circulate and cool the air.

1 Motor 2 Motor housing (housing)
3 Coil 4 Stator 7, 7b, 7c Cooling water channel (cooling medium channel)
7a Water channel extension (channel extension)
7d water channel bend (communication flow path)
8 Cooling water supply port (cooling medium supply port)
9 Cooling water drain (cooling medium drain)

Claims (5)

A cooling medium flow path through which a cooling medium for cooling the motor is circulated is provided along a circumferential direction inside the housing, and a cooling medium supply port is provided at one end side of the cooling medium flow path, and the other end of the cooling medium flow path. In the housing structure of the motor, provided with a cooling medium discharge port on the side, and the cooling medium flow path is located in a part of a predetermined range instead of substantially the entire circumference in the circumferential direction inside the housing.
A motor housing, wherein a flow path extension extending along a circumferential direction inside the housing is integrally formed from either the cooling medium supply port or the cooling medium discharge port of the cooling medium flow path. Construction.   The closed tip side extending in the circumferential direction of the flow path extension is located in the vicinity of the cooling medium discharge port or the cooling medium supply port on the other end side of the cooling medium flow path. The motor housing structure according to claim 1.   3. The motor housing according to claim 2, wherein a closed distal end side extending in a circumferential direction of the flow path extension portion is positioned below a proximal end side of the flow path extension portion. Construction.   2. The motor according to claim 1, wherein a plurality of the cooling medium flow paths are provided in the axial direction of the housing, and each of the cooling medium flow paths is connected via a communication flow path portion. Housing structure.   At least one of the cooling medium flow path, the flow path extension, and the communication flow path is located at least in a part of the housing in the circumferential direction with respect to the axial direction of the housing. The motor housing structure according to claim 4.

Images