JP4341577B2 - Vehicle drive device - Google Patents

Description

  The present invention relates to a vehicle drive device, and more particularly to a vehicle drive device including a pressure release valve provided in a sealed case.

In recent years, automobiles equipped with motors for propelling vehicles such as electric cars and hybrid cars have become familiar. Japanese Patent Laid-Open No. 9-48250 (Patent Document 1) discloses an air breather structure of a power train for an electric vehicle. In this technique, air around the motor is released to the outside of the motor case through the air breather chamber, and the high temperature and high pressure of the space due to the heat generated from the motor and the accompanying condensation can be reduced.
JP-A-9-48250 Japanese Utility Model Publication 1-115083

  However, in the technique disclosed in Japanese Patent Laid-Open No. 9-48250 (Patent Document 1), the space for accommodating the motor is connected to the air breather chamber through a plurality of valve passages, but the air breather chamber communicates with the outside air. Is one place.

  For this reason, the internal pressure of a motor case will rise, when problems, such as clogging or destruction by this environmental factor etc., occur in the part connected with this external air. For this reason, in order to prevent a pressure rise, it is possible to provide a pressure release valve.

  FIG. 5 is a schematic view showing the structure of the pressure release valve.

  Referring to FIG. 5, the pressure release valve 500 has a structure in which a sphere 506 placed on a cylindrical projection 502 is pulled from the inside of the case with a spring 508 and the sphere 506 is covered with a cap 504. As a result, when the internal pressure of the case rises, the sphere 506 is pushed up and air is discharged as shown by the arrow in FIG.

  However, it is set when the sphere 506 and the cylindrical projection 502 are fixed or the cap 504 and the cylindrical projection 502 are fixed due to environmental factors such as adhesion of snow melting agent or generation of rust in winter. The internal pressure will rise above the open pressure.

  Motors and the like are composed of parts containing a large amount of insulating materials such as enameled wires and interphase insulators. When the internal pressure rises, degradation of these insulating materials due to hydrolysis is promoted. For this reason, it is necessary to use an expensive grade insulating material having high hydrolysis resistance.

  An object of the present invention is to provide a vehicle drive device with reduced costs while maintaining reliability.

  In summary, the present invention is a vehicle drive device, and includes a sealed case that houses a rotating electrical machine for driving a vehicle, and a plurality of pressure release valves provided in the sealed case.

  Preferably, the directions in which the plurality of pressure release valves are attached to the sealed case are different from each other.

  Preferably, the plurality of pressure release valves include first and second pressure release valves having different release pressures.

  Preferably, the vehicle drive device further includes first and second rotating electric machines. The sealed case includes a partition wall having a communication path that partitions the first space that houses the first rotating electrical machine from the second space that houses the second rotating electrical machine. A first pressure release valve of the plurality of pressure release valves is provided in the first space portion. A second pressure relief valve of the plurality of pressure relief valves is provided in the second space portion.

  According to the present invention, it is possible to reduce the cost while maintaining the insulation reliability of the vehicle drive device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a cross-sectional view showing a structure of a vehicle drive device 1 according to the first embodiment. In addition, although the vehicle drive device mounted in a hybrid vehicle is demonstrated as an example, this invention is applicable suitably also to vehicles, such as an electric vehicle and a fuel cell vehicle.

  Referring to FIG. 1, vehicle drive device 1 includes a motor generator MG1, a motor generator MG2, and a composite gear 80.

  Motor generator MG1 mainly starts an engine (not shown) and generates electric power after the engine is started.

  Motor generator MG1 includes a rotor 24 and a stator 16. The stator 16 includes a stator core 18 and a stator coil 20. The stator core 18 is fixed by a case 8 and bolts 22.

  The rotor 24 includes a hollow shaft 30, a rotor core 26 on which electromagnetic steel plates are laminated, and a permanent magnet 28 embedded in the rotor core 26. A rotating shaft 14 that transmits the rotation of the engine is passed through the hollow shaft 30. The rotation of the engine is transmitted to the rotating shaft 14 via the transaxle damper 13.

  A lid 10 is attached to the case 8 with bolts 12. A seal member 32 is provided in the gap between the lid 10 and the rotary shaft 14.

  The shaft 30 is supported by a ball bearing 34 so as to be rotatable with respect to the case. A resolver 38 as a rotation sensor is attached to the shaft 30. A part of resolver 38 is fixed by a bolt 40 to a partition wall that divides a space for accommodating motor generator MG1 from a space for accommodating composite gear 80 and motor generator MG2. A ball bearing 36 is provided between the partition wall and the shaft 30 to rotatably support the shaft 30.

  Since the partition wall to which the bolt 40 is attached is provided with a communication path at the top, the space in which the motor generator MG1 is accommodated and the space in the other part have the same atmospheric pressure.

  Motor generator MG2 is driven mainly by a high voltage battery and operates as a motor for generating wheel driving force. However, it also operates as a generator that recovers electric power by performing regenerative braking during braking.

  Motor generator MG2 includes a rotor 54 and a stator 46. The stator 46 includes a stator core 48 and a stator coil 50. The stator core 48 is fixed to the case 4 with bolts 52. A lid 2 is attached to the case 4 with bolts 6.

  The rotor 54 includes a hollow shaft 60, a rotor core 56 on which electromagnetic steel plates are laminated, and a permanent magnet 58 embedded in the rotor core 56. The shaft 60 is rotatably supported by a ball bearing 64 attached to the lid 2 and a ball bearing 66 attached to the partition wall.

  A rotating shaft 72 for transmitting the rotation of the engine to the oil pump passes through a hollow portion of the shaft 60. A resolver 68 for detecting the rotation of the shaft 60 is attached to the lid 2 by a bolt 70.

  Compound gear 80 includes a planetary gear 84 that is a reduction gear that decelerates rotation of motor generator MG2, and a planetary gear 82 that operates as a power split device that splits power between an engine (not shown) and motor generators MG1 and MG2.

  Planetary gear 84 includes a sun gear 92 fitted to shaft 60, a pinion gear 88 meshing with the sun gear, and a planetary carrier 90 fixed to a case supporting the pinion gear. A ball bearing 94 is provided between the planetary carrier 90 and the rotating shaft 14.

  The planetary gear 82 includes a sun gear 96 that is spline-fitted with the shaft 30, a pinion gear 98 that meshes with the sun gear 96, and a planetary carrier 100 that supports the rotation shaft of the pinion gear 98. Planetary carrier 100 is fixed to rotating shaft 14 that transmits the rotation of the engine, and rotates integrally with rotating shaft 14.

  In the compound gear 80, a ring gear that meshes with the pinion gear 88 in the planetary gear 84 is engraved on the inner circumference, a ring gear that meshes with the pinion gear 98 in the planetary gear 82 is engraved on the inner circumference, and a gear that meshes with the counter driven gear 106 is further engraved on the outer circumference. The counter drive gear 86 is included.

  Although not shown, the space in which the counter driven gear 106 is accommodated has an airtight structure using an oil seal.

  In FIG. 1, a pressure release valve 150 is provided in a vertical direction in the case 8 that is a portion that houses the motor generator MG <b> 1. The case 4 that houses the motor generator MG2 is provided with a pressure release valve 152 in the horizontal direction. The detailed structure of the pressure release valves 150 and 152 can be the same as that of the pressure release valve 500 described with reference to FIG.

  As described above, by providing the pressure release valves in which the attachment positions are dispersed so as to be dispersed in the attachment direction, for example, it is possible to reduce the probability that the spray mixed with the snow melting agent is applied to all of the plurality of pressure release valves. As a result, the problem that the pressure release valve is clogged with rust or mud can be avoided, and the internal pressure inside the sealed case can be prevented from rising due to heat from the motor.

  FIG. 2 is a diagram for explaining the effect of the present invention.

  Referring to FIG. 2, the insulating material used for a motor or the like includes an expensive material having a hydrolysis degradation guarantee range indicated by line A and a relatively inexpensive material having a hydrolysis degradation guarantee range indicated by line B. There is.

  In consideration of the failure that the pressure release valve does not function, the maximum motor temperature is Tmax and the pressure P2 is the worst condition, and the hydrolysis deterioration guarantee range is required up to the point Y2. For this reason, expensive materials that guarantee the range indicated by line A must be used.

  Examples of such expensive materials include resins such as polyphenylene sulfide (PPS), polyether nitrile (PEN), and polyether ether ketone (PEEK).

  According to the present invention, by using a plurality of pressure release valves, it is possible to reliably prevent the pressure from becoming equal to or higher than the release pressure P1 of the pressure release valve, so it is only necessary to guarantee the condition indicated by the point Y1. For this reason, an inexpensive material having a guaranteed range indicated by the line B can be used.

  Examples of such an inexpensive material include resins such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and polyamide (PA) 66 (also referred to as nylon 66).

[Embodiment 2]
FIG. 3 is a cross-sectional view showing the structure of vehicle drive device 1A of the second embodiment.

  Referring to FIG. 3, vehicle drive device 1 </ b> A includes pressure release valves 200, 202 instead of pressure release valves 150, 152 in the structure of vehicle drive device 1 shown in FIG. 1. Since the configuration of the other parts is similar to that of vehicle drive device 1, vehicle drive device 1 </ b> A will not be described repeatedly.

  The pressure release valves 200 and 202 are respectively provided in the cases 8 and 4 so as to face in the vertical direction. The detailed structure of the pressure release valves 200 and 202 can be the same as that of the pressure release valve 500 described with reference to FIG. The opening pressure of the pressure release valve 200 is a megapascal (MPa), and the opening pressure of the pressure release valve 202 is b megapascal different from a.

  By providing a plurality of pressure release valves having different release pressures in a case that constitutes one sealed space in this way, usually one of the pressure release valves functions with priority, and if that pressure release valve malfunctions, If it has stuck, the other pressure relief valve operates. If the release pressure of the pressure release valve that operates normally is set in the same way as before and another release valve with a slightly higher release pressure is provided, the disadvantages such as water intrusion from the pressure release valve are conventional. Although it is the same level as technology, it can be avoided that the internal pressure in the sealed case increases. This makes it possible to employ an inexpensive insulating material as in the first embodiment.

[Embodiment 3]
FIG. 4 is a cross-sectional view showing the structure of vehicle drive device 1B of the third embodiment.

  4 includes pressure release valves 250, 252, 254, and 256 instead of pressure release valves 150 and 152 in the configuration of vehicle drive apparatus 1 shown in FIG.

  The detailed structure of the pressure release valves 250, 252, 254, and 256 can be the same as that of the pressure release valve 500 described in FIG.

  The vehicle drive device 1B includes a sealed case including lids 2 and 10 and cases 4 and 8 that house a rotating electrical machine for driving a vehicle, and a plurality of pressure release valves 250, 252, 254, and 256 provided in the sealed case. Prepare. The pressure release valves 250 and 252 are attached to the sealed case in different directions, and the pressure release valves 254 and 256 are attached to the sealed case in different directions.

  Vehicle drive device 1B further includes motor generators MG1 and MG2, which are first and second rotating electric machines. The sealed case includes a partition wall having a communication path that partitions the first space that houses motor generator MG1 from the second space that houses motor generator MG2. Among the plurality of pressure release valves, the pressure release valve 250 is provided in the case 8 which is the first space portion. The pressure release valves 252, 254 and 256 are provided in the case 4 which is the second space portion. Preferably, the opening pressures of the plurality of pressure release valves may be set to different values as in the second embodiment.

  Since the structure of the other parts is the same as that of vehicle drive device 1 described in FIG. 1, vehicle drive device 1B shown in FIG. 4 will not be described repeatedly.

  In the third embodiment, pressure release valve 250 is provided for case 8 accommodating motor generator MG1, pressure release valve 252 is provided for case 4, and pressure release valves 254, 256 are provided for lid 2. ing. The mounting direction of the pressure release valves 250 and 254 is the vertical direction, and the mounting direction of the pressure release valves 252 and 256 is the horizontal direction.

  Thus, by providing a plurality of pressure release valves with different arrangements and different mounting directions for one sealed case, it is possible to more reliably prevent the pressure inside the case from increasing abnormally. be able to. Thereby, an inexpensive insulating material can be used as described in the first and second embodiments.

  The embodiment 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, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a cross-sectional view illustrating a structure of a vehicle drive device 1 according to a first embodiment. It is a figure for demonstrating the effect of this invention. It is sectional drawing which showed the structure of 1 A of vehicle drive devices of Embodiment 2. FIG. It is sectional drawing which showed the structure of the vehicle drive device 1B of Embodiment 3. FIG. It is the schematic which showed the structure of the pressure release valve.

Explanation of symbols

  1,1A, 1B Vehicle drive device, 2,10 lid, 4,8 case, 6,12,22,40,52,70 bolt, 13 transaxle damper, 14 rotating shaft, 16,46 stator, 18,48 stator core , 20, 50 Stator coil, 24, 54 Rotor, 26, 56 Rotor core, 28, 58 Permanent magnet, 60, 30 Shaft, 32 Seal member, 34, 36, 64, 66, 94, 102, 104 Ball bearing, 38, 68 resolver, 72 rotating shaft, 80 compound gear, 82,84 planetary gear, 86 counter drive gear, 88,98 pinion gear, 90,100 planetary carrier, 92,96 sun gear, 106 counter driven gear, 150,152,200,202,250 , 252,254,256,500 Pressure release valve, 502 cylindrical protrusion, 504 cap, 506 sphere, MG1, MG2 motor generator.

Claims (3)

A sealed case that houses a rotating electrical machine for driving the vehicle;
A plurality of pressure release valves provided in the sealed case ;
The vehicle driving device, wherein the plurality of pressure release valves protrude from the sealed case in directions of leading ends . A sealed case that houses a rotating electrical machine for driving the vehicle;
A plurality of pressure release valves provided in the sealed case;
The plurality of pressure relief valves are:
First having different opening pressure each other, comprising a second pressure relief valve, drive both drive. A sealed case that houses a rotating electrical machine for driving the vehicle;
A plurality of pressure release valves provided in the sealed case;
First, a second rotating electric machine,
The sealed case includes a partition wall having a communication path that partitions a first space that houses the first rotating electrical machine from a second space that houses the second rotating electrical machine,
A first pressure relief valve of the plurality of pressure relief valves is provided in the first space portion;
It said second pressure relief valve of the plurality of pressure relief valve is provided in the second space portion, the car two drive devices.

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