JP4661614B2 - Cooling pipe fixing structure and electric vehicle - Google Patents

Description

  The present invention relates to a cooling pipe fixing structure and an electric vehicle, and more particularly to a cooling pipe fixing structure through which a cooling liquid flows and an electric vehicle including the structure.

  Japanese Patent Application Laid-Open No. 8-130856 (Patent Document 1) discloses a motor cooling circuit that cools oil by flowing oil through an oil passage using an oil pump and dropping the oil onto a coil end.

  Japanese Patent Laying-Open No. 2005-253263 (Patent Document 2) also discloses a cooling device for an electric motor that performs cooling using an oil pump and an oil passage in the same manner as described above.

  Japanese Patent Application Laid-Open No. 7-298524 (Patent Document 3) discloses providing a passage through which a refrigerant passes inside the stator.

Japanese Patent Laying-Open No. 2004-72950 (Patent Document 4) discloses a support structure for a cooling pipe attached to a stator core.
JP-A-8-130856 JP 2005-253263 A JP 7-298524 A JP 2004-72950 A

  As described in Patent Documents 1 and 2, when cooling is performed using an oil pump and an oil passage, it is necessary to firmly fix the cooling pipe. If the cooling pipe fixing structure is damaged by vibration, the refrigerant may not be supplied to an appropriate position, and the cooling performance may deteriorate. On the other hand, from the viewpoint of downsizing the equipment, it is desirable to configure a compact cooling pipe fixing structure.

  On the other hand, Patent Documents 1 and 2 do not specifically disclose a pipe fixing structure capable of exhibiting sufficient fixing strength. The structure described in Patent Document 3 is provided with a refrigerant passage inside the stator, and is completely different from the present invention in which a pipe is provided separately from an object to be cooled. In Patent Document 4, a pipe is fixed using a bracket. However, when fixing using a bracket, it is necessary to fix with a bolt, and it is necessary to secure a space for installing the bolt. As a result, downsizing of the device on which the cooling pipe is mounted is hindered.

  The present invention has been made in view of the above problems, and an object of the present invention includes a cooling pipe fixing structure that is compact and suppresses a decrease in cooling efficiency during vibration, and the structure. It is to provide an electric vehicle.

The cooling pipe fixing structure according to the present invention is provided separately from the casing, the object to be cooled provided in the casing, and provided at one end of the pipe through which the liquid for cooling the object to be cooled flows. A support portion that contacts the inner surface of the housing and an elastic member that is provided at the other end of the pipe and is press-fitted into the housing, and one end of the pipe is inserted into an insertion hole provided in the housing The hole has a tapered portion whose opening width narrows toward the downstream side in the pipe insertion direction.

  According to the above configuration, when the elastic member is press-fitted into the casing, even when vibration is applied, the vibration is absorbed by the elastic member, and a firm fixed state is maintained. As a result, a decrease in cooling performance is suppressed. In addition, the support structure is reduced in size by supporting the cooling pipe by sandwiching it. As a result, it is possible to obtain a cooling pipe fixing structure that is compact and suppresses a decrease in cooling efficiency during vibration.

  In the cooling pipe fixing structure, preferably, a cooling liquid discharge port is provided on a side surface of the pipe, and a rotation preventing structure for suppressing rotation of the pipe around the axial direction is provided.

  According to the above configuration, it is possible to stabilize the discharge direction of the liquid from the discharge port by suppressing the rotation of the pipe. As a result, the cooling efficiency of the object to be cooled can be improved.

  In the cooling pipe fixing structure, preferably, the pipe has a protruding portion protruding from a side surface of the pipe, and the elastic member is sandwiched between the protruding portion and the housing in the axial direction of the pipe.

  According to the said structure, the elastic force by a deformation | transformation of an elastic member can be hold | maintained by clamping an elastic member with a protrusion part and a housing | casing. As a result, a firmly fixed state of the pipe is maintained.

  In the cooling pipe fixing structure, as an example, the object to be cooled is a stator of a rotating electrical machine.

  The stator generates heat when the rotating electrical machine is driven. On the other hand, according to the fixing structure of the cooling pipe, the stator can be efficiently cooled while suppressing an increase in the size of the rotating electrical machine.

  The electric vehicle according to the present invention includes the cooling pipe fixing structure described above. As a result, an electric vehicle including a cooling pipe fixing structure having sufficient fixing strength against vibration during traveling and collision can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the fixing structure of the cooling pipe which was compact and suppressed the fall of the cooling efficiency at the time of a vibration is obtained.

  Embodiments of a cooling pipe fixing structure and an electric vehicle according to the present invention will be described below. Note that the same or corresponding portions are denoted by the same reference numerals, and the description thereof may not be repeated.

  FIG. 1 is a cross-sectional view of a drive unit to which a cooling pipe fixing structure according to one embodiment of the present invention is applied.

  Referring to FIG. 1, drive unit 1 mounted on a hybrid vehicle as an “electric vehicle” includes rotating electric machines 100, 200, a planetary gear mechanism 300, a speed reduction mechanism 400, a differential mechanism 500, and a drive shaft receiving portion. 600. The rotating electrical machines 100 and 200, the planetary gear mechanism 300, the speed reduction mechanism 400, and the differential mechanism 500 are provided in the casing 700.

  The rotating electrical machines 100 and 200 are motor generators having a function as an electric motor or a generator. The rotating electrical machines 100 and 200 include rotating shafts 110 and 210 rotatably attached to the casing 700 via bearings 120 and 220, rotors 130 and 230 attached to the rotating shafts 110 and 210, and a stator 140, 240.

  Rotors 130 and 230 each have a rotor core and a magnet embedded in the rotor core. The rotor core is configured by stacking plate-like magnetic bodies such as iron or iron alloy. For example, the magnets are arranged at substantially equal intervals in the vicinity of the outer periphery of the rotor core.

  The stators 140 and 240 have ring-shaped stator cores 141 and 241 and stator coils 142 and 242 wound around the stator cores 141 and 241, respectively. Stator coils 142 and 242 are each electrically connected to the battery via a cable.

  The stator cores 141 and 241 are configured by laminating plate-like magnetic bodies such as iron or iron alloy. A plurality of teeth portions (not shown) and slot portions (not shown) as recesses formed between the teeth portions are formed on the inner peripheral surfaces of the stator cores 141 and 241. The slot portion is provided so as to open to the inner peripheral side of the stator cores 141 and 241.

  Stator coils 142 and 242 including three winding phases, U phase, V phase, and W phase, are wound around the tooth portion so as to fit into the slot portion. The U phase, V phase and W phase of the stator coils 142 and 242 are wound so as to deviate from each other on the circumference.

  Planetary gear mechanism 300 is constituted by a plurality of planetary gears, for example, and has a power split function and a speed reduction function. Here, the ring gear in the plurality of planetary gears may be constituted by one cylindrical member.

  During operation of the drive unit 1, power output from an engine (not shown) is transmitted to the shaft 2 and divided into two paths by the planetary gear mechanism 300.

  One of the two paths is a path that is transmitted from the speed reduction mechanism 400 to the drive shaft receiving portion 600 via the differential mechanism 500. The driving force transmitted to the drive shaft receiving portion 600 is transmitted as a rotational force to a wheel (not shown) via a drive shaft (not shown), thereby causing the vehicle to travel.

  The other is a path for driving the rotating electrical machine 100 to generate power. The rotating electrical machine 100 generates electric power using the engine power distributed by the planetary gear mechanism 300. The electric power generated by the rotating electrical machine 100 is properly used according to the traveling state of the vehicle and the state of the battery (not shown). For example, during normal running and sudden acceleration of the vehicle, the electric power generated by the rotating electrical machine 100 becomes the power for driving the rotating electrical machine 200 as it is. On the other hand, under the conditions determined in the battery, the electric power generated by the rotating electrical machine 100 is stored in the battery via an inverter and a converter (not shown).

  The rotating electric machine 200 is driven by at least one of the electric power stored in the battery and the electric power generated by the rotating electric machine 100. The driving force of the rotating electrical machine 200 is transmitted from the speed reduction mechanism 400 to the drive shaft receiving portion 600 via the differential mechanism 500. In this way, the driving force of the engine can be assisted by the driving force from the rotating electrical machine, or the vehicle can be driven only by the driving force from the rotating electrical machine 200.

  On the other hand, during regenerative braking of the hybrid vehicle, the wheels are rotated by the inertial force of the vehicle body. The rotating electrical machine 200 is driven through the drive shaft receiving portion 600, the differential mechanism 500, and the speed reduction mechanism 400 by the rotational force from the wheels. At this time, the rotating electrical machine 200 operates as a generator. Thus, the rotating electrical machine 200 acts as a regenerative brake that converts braking energy into electric power. The electric power generated by the rotating electrical machine 200 is stored in the battery via the inverter.

  The use of rotating electrical machines 100 and 200 is not limited to a hybrid vehicle (HV), but may be mounted on another “electric vehicle” (for example, a fuel cell vehicle or an electric vehicle).

  In the drive unit 1 configured as described above, the stator coils 142 and 242 of the rotating electrical machines 100 and 200 generate heat when driving force is generated and when power is generated. On the other hand, in the drive unit 1, the stator coils 142 and 242 are cooled by supplying lubricating oil (cooling oil) to the stator coils 142 and 242. For example, the cooling oil is scraped up by the rotation of the ring gear of the differential mechanism 500, temporarily stored in the oil reservoir, and supplied to the stator coil by flowing from the oil reservoir toward the stator coil.

  However, depending on the structure of the drive unit 1, the stator coils 142 and 242 may not be cooled only by the oil that is scraped up by the ring gear. In some cases, a cooling oil pipe (cooling pipe) is installed in the vicinity of the stator, and the oil is supplied to the stator coil by flowing oil into the cooling pipe using an oil pump. In this case, it is necessary to form a cooling pipe fixing structure that is compact and secures a strong fixing. For example, when the cooling pipe fixing structure is a cantilever structure, the tip of the pipe is likely to swing, and the discharge direction of the cooling oil becomes unstable. As a result, the cooling performance may deteriorate. In addition, in the case of a cantilever structure, excessive stress is applied to the pipe fixing structure due to vehicle vibration, collision vibration, or the like, which may cause damage.

  FIG. 2 is an enlarged cross-sectional view showing the periphery of the stator 140 of the drive unit 1 according to the present embodiment. Referring to FIG. 2, cooling pipe 800 is provided on the outer peripheral side of stator core 141. By driving an oil pump (not shown), the oil flows into the cooling pipe 800 from the direction of the arrow DR1 through the oil passage 900. The oil flowing into the cooling pipe 800 flows in the direction of the arrow DR2 in the cooling pipe 800. A discharge port 810 for discharging oil is provided on the side surface of the cooling pipe 800. Oil flowing through the cooling pipe 800 is discharged from the discharge port 810 toward the coil end of the stator coil 142. Thereby, the stator coil 142 is cooled.

  A support ring 820 is attached to one end of the cooling pipe 800, and the end is inserted into an insertion hole 710 provided in the casing 700. The other end of the cooling pipe 800 is supported by a cover 720 that is a part of the casing 700 via a rubber cap 830.

  When the cooling pipe 800 is assembled to the casing 700, first, the support ring 820 and the rubber cap 830 are attached to the cooling pipe 800. Then, the end of the cooling pipe 800 on which the support ring 820 is attached is inserted into the insertion hole 710 of the casing 700. Then, the cover 720 is assembled from above the rubber cap 830. At this time, the rubber cap 830 is press-fitted into a hole provided in the cover 720 and is deformed by the pressure of the cover assembly. The cooling pipe 800 is firmly fixed by the elastic force accompanying this deformation.

  FIG. 3 is a view showing a state in which the rubber cap 830 is viewed from the axial direction of the cooling pipe 800. FIG. 4 is an enlarged view showing a state where the support ring 820 and the rubber cap 830 are attached to the cooling pipe 800. 3 and 4, the pipe 800 is provided with a bracket 840 that protrudes from the side surface of the pipe. When the bracket 840 comes into contact with the case or the cover, the rotation of the cooling pipe 800 around the axial direction is suppressed. By suppressing the rotation of the cooling pipe 800, the oil discharge direction from the discharge port 810 is stabilized. Then, the cooling oil can be stably supplied to a predetermined object to be cooled (here, the stator coil 142). In addition, by holding the rubber cap 830 in the axial direction of the cooling pipe 800 between the bracket 840 and the cover 720 that are harder than the rubber cap 830, the elastic force due to the deformation of the rubber cap 830 can be maintained. Note that the end surface in the axial direction of the bracket 840 that contacts the rubber cap 830 is formed flat.

  FIG. 5 is an enlarged view showing the insertion hole 710 of the cooling pipe 800 provided in the casing 700. Referring to FIG. 5, insertion hole 710 has a tapered portion 711 whose opening width becomes narrower toward the downstream side in the insertion direction of cooling pipe 800. By doing in this way, it becomes easy to perform axial alignment when inserting the cooling pipe 800 into the insertion hole 710. As a result, productivity is improved. In addition, since the mounting angle of the cooling pipe 800 can be determined with high accuracy, oil can be stably supplied to a predetermined position. As a result, the cooling efficiency of the stator coil 142 is improved.

  In addition, although the example which provided the cooling pipe 800 in the outer periphery of the rotary electric machine 100 was demonstrated above, the cooling pipe 800 may be provided in the outer periphery of the rotary electric machine 200. FIG.

  The above contents are summarized as follows. That is, the cooling pipe fixing structure according to the present embodiment is provided separately from the casing 700 as the “casing” and the stator 140 as the “object to be cooled” provided in the casing 700. A cooling pipe 800 through which a cooling liquid (cooling oil) flows, a support ring 820 provided at one end of the cooling pipe 800 as a “supporting portion” that contacts the inner surface of the casing 700, and the other end of the cooling pipe 800. And a rubber cap 830 as an “elastic member” that is press-fitted into the cover 720 (or provided integrally with the cover 720). The rubber cap 830 can be deformed by the pressure when the cover 720 is assembled. A cooling oil discharge port 810 is provided on the side surface of the cooling pipe 800. The cooling pipe 800 is provided with a bracket 840 as a “non-rotating structure” that suppresses the rotation of the cooling pipe 800 around the axial direction. The bracket 840 is a “projection” that projects from the side surface of the cooling pipe 800. The rubber cap 830 is sandwiched between the bracket 840 and the cover 720 in the axial direction of the cooling pipe 800.

  According to the fixing structure of the cooling pipe according to the present invention, even when vibration is applied, the vibration is absorbed by the rubber cap 830 and a firm fixed state is maintained. As a result, a decrease in cooling performance is suppressed. Further, the support structure is reduced in size by supporting the cooling pipe 800 in a sandwiched manner. As a result, it is possible to obtain a cooling pipe fixing structure that is compact and suppresses a decrease in cooling efficiency during vibration. Moreover, the rotation direction of the cooling pipe 800 is suppressed by the bracket 840, so that the oil discharge direction from the discharge port 810 can be stabilized.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing of the drive unit to which the fixing structure of the cooling pipe which concerns on one embodiment of this invention is applied. It is an expanded sectional view which shows the stator periphery of the drive unit shown by FIG. It is a figure which shows the state which looked at the rubber cap shown by FIG. 2 from the axial direction of a cooling pipe. It is an enlarged view which shows the state which attached the support ring and the rubber cap to the cooling pipe shown by FIG. It is an enlarged view which shows the insertion hole of the cooling pipe provided in the casing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Drive unit, 2 shafts, 100,200 Rotary electric machine, 110,210 Rotary shaft, 120,220 Bearing, 130,230 Rotor, 140,240 Stator, 141,241 Stator core, 142,242 Stator coil, 300 Planetary gear mechanism, 400 Deceleration mechanism, 500 differential mechanism, 600 drive shaft receiving part, 700 casing, 710 insertion hole, 711 taper part, 720 cover, 800 cooling pipe, 810 discharge port, 820 support ring, 830 rubber cap, 840 bracket, 900 oil passage.

Claims (5)

A housing,
A pipe provided separately from an object to be cooled provided in the housing, and a pipe through which a liquid for cooling the object to be cooled flows;
A support provided at one end of the pipe and in contact with the inner surface of the housing;
Provided at the other end of the pipe, and an elastic member which is press-fitted into the housing,
One end of the pipe is inserted into an insertion hole provided in the housing, and the insertion hole has a tapered portion whose opening width becomes narrower toward the downstream side in the insertion direction of the pipe. . A discharge port of the cooling liquid is provided on a side surface of the pipe;
The cooling pipe fixing structure according to claim 1, further comprising a rotation prevention structure that suppresses rotation of the pipe around an axial direction. The pipe has a protrusion protruding from a side surface of the pipe;
The cooling pipe fixing structure according to claim 1 or 2, wherein the elastic member is sandwiched in the axial direction of the pipe by the protrusion and the housing.   The cooling pipe fixing structure according to claim 1, wherein the object to be cooled is a stator of a rotating electric machine.   An electric vehicle comprising the cooling pipe fixing structure according to any one of claims 1 to 4.

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