JP2009171767A - Drive unit for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit for a vehicle, which enhances output efficiency of a motor, in the drive unit with a differential and the motor integrated. <P>SOLUTION: The drive unit for the vehicle with the motor 30 and the differential 14 integrated includes: a housing 16 for holding the motor and the differential; a water gallery 70 which is provided in the housing and cools the drive unit; a radiator 86 to cool cooling water; a cooling-water pump 80; a cooling water control means; and a temperature detecting means of the differential. At least a portion of the water gallery is provided between the motor and the differential. When the differential temperature detected by the temperature detecting means of the differential is higher than a predetermined temperature, the cooling water control means operates the cooling-water pump, and controls cooling so that the cooling water may flow through the water gallery provided between the motor and the differential. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle drive device, and more particularly to a vehicle drive device in which a motor that drives a drive shaft and a differential provided downstream of the drive shaft are integrated.

Patent Document 1 discloses a vehicle drive device in which a motor provided on a drive shaft to which engine output is transmitted and drives a wheel and a differential provided at a downstream end of the drive shaft are integrated. Yes.
Patent Document 2 discloses a cooling device for cooling a motor that drives wheels in a hybrid electric vehicle.

Japanese Translation of National Publication No. 07-505591 JP 2002-004860 A

  Here, in the drive device described in Patent Document 1 described above, for example, when the differential generates heat and becomes high temperature during high-speed traveling or the like, the heat of the differential is applied to the motor housed in the housing integrally with such differential. As a result, the output efficiency of the motor may be reduced. On the other hand, since the motor operates efficiently at an appropriate temperature, the output efficiency of the motor decreases when the engine is cold such as immediately after the engine is started. Problems such as these cannot be solved by the cooling device described in Patent Document 2 described above. At present, the motor temperature is efficiently reduced when the motor is hot, and the motor temperature is prevented from increasing when the motor is cold. There is a need for a motor cooling system that does not exist.

  The present invention has been made to solve the above-described problems of the prior art, and provides a vehicle drive device that can increase the output efficiency of a motor in a drive device in which a differential and a motor are integrated. With the goal.

  In order to achieve the above object, according to the present invention, a motor that is provided on a drive shaft and drives a wheel via the drive shaft, and a differential that is provided at a downstream end portion of the drive shaft, A vehicle drive device in which a motor and a differential are integrated, a housing for housing the motor and a differential so as to be integrated, and cooling the drive water provided in the housing to circulate cooling water. A water gallery, a radiator for cooling the cooling water, a cooling water pump for circulating the cooling water, a cooling water control means for controlling the cooling water pump, and a differential temperature detection means for detecting the temperature of the differential. However, at least a part of the water gallery is provided between the motor and the differential, and the cooling water control means is the differential. When the differential temperature detected by the temperature detecting means is higher than a predetermined temperature, the cooling water pump is operated to control the cooling so that the cooling water flows through the water gallery provided between the motor and the differential. It is a feature.

  In the present invention configured as described above, at least a part of the water gallery is provided between the motor and the differential, and when the temperature of the differential is higher than a predetermined temperature, the cooling water flows through the water gallery. Therefore, when the temperature of the differential is high, the temperature of the differential can be lowered and the transfer of heat from the differential to the motor can be prevented. As a result, the temperature rise of the motor can be prevented, and the output efficiency of the motor can be increased.

In the present invention, it is preferable that the apparatus further includes motor temperature detection means for detecting the temperature of the motor, and the cooling water control means detects the differential temperature detected by the differential temperature detection means by the motor temperature detection means. Cooling control is performed when the motor temperature is higher.
In the present invention configured as described above, when there is a large temperature difference where heat is largely transferred from the differential to the motor, that is, when the temperature of the differential is higher than the motor temperature, the motor and the differential Since the cooling water flows through the water gallery provided between the two, the heat transfer from the differential to the motor can be suppressed more reliably, and the temperature rise of the motor can be prevented.

In the present invention, it is preferable that the cooling water control unit is configured to control the motor in the cooling control as the temperature difference between the differential temperature detected by the differential temperature detection unit and the motor temperature detected by the motor temperature detection unit increases. The cooling water pump is operated so that the amount of cooling water flowing in the water gallery provided between the first and second differentials increases.
In the present invention configured as described above, as the temperature difference between the differential temperature and the motor temperature is larger, the amount of cooling water flowing through the water gallery provided between the motor and the differential is increased. It is possible to prevent the temperature of the motor from rising by suppressing the transfer of heat to the motor.

In the present invention, it is preferable that the cooling water control unit does not perform cooling control when the motor temperature detected by the motor temperature detection unit is lower than a predetermined temperature, and does not perform cooling control and is provided between the motor and the differential. The operation of the cooling water pump is suppressed so that the cooling water does not flow through the gallery.
In the present invention configured as described above, when the temperature of the motor is lower than a predetermined temperature, for example, a temperature at which the output efficiency of the motor is lowered, the cooling water does not flow into the water gallery between the motor and the differential, It is possible to increase the output efficiency of the motor by raising the temperature of the motor by deliberately transferring the heat to the motor.

In the present invention, it is preferable to further include a cooling fan for cooling the radiator, and the cooling water control means performs cooling control and operates the cooling fan when the vehicle is stopped.
In the present invention configured as above, the cooling fan is operated when the vehicle is stopped when the traveling wind does not hit the radiator, and the cooling water flowing in the water gallery between the motor and the differential is cooled more reliably. Thus, the heat transfer from the differential to the motor can be suppressed more reliably, and the temperature rise of the motor can be prevented.

In the present invention, it is preferable that the engine further includes an engine that is connected to the drive shaft and drives the wheels via the drive shaft, and intermittent means that connects or disconnects the motor and the drive shaft. The control means performs cooling control when the output of the engine is transmitted to the drive shaft and the motor and the drive shaft are not connected by the intermittent means.
In the present invention configured as described above, when the output of the engine is transmitted to the drive shaft and the motor and the drive shaft are not connected, that is, the temperature of the differential rises, the temperature of the differential and the basic In particular, in the travel mode in which the difference from the temperature of the stopped motor becomes large, the heat transfer from the differential to the motor can be suppressed more reliably, and the temperature rise of the motor can be prevented.

  According to the vehicle drive device of the present invention, the output efficiency of the motor can be increased in the drive device in which the differential and the motor are integrated.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic view showing a configuration of a drive unit to which a vehicle drive device according to an embodiment of the present invention is applied. FIG. 2 is a cross-sectional view of the vehicle drive device according to the embodiment of the present invention as viewed from the side. is there.

  The drive unit 1 can properly use the driving states of the motor running mode, the engine running mode, the motor torque assist running mode, and the deceleration energy regeneration mode, and includes the engine 2, the motor generator 4, the torque converter 6, the automatic transmission 8, and the propeller. It has a shaft (drive shaft) 10, a drive device 12, and a rear differential device (differential device) 14.

  As shown in FIG. 2, the drive device 12 includes a housing (accommodating chamber) 16 that accommodates a motor (30) and a rear differential device 14 described later. A front case 17 that houses a planetary gear (22) and an intermittent device (34), which will be described later, is attached to the front of the housing 16, and a cover 18 that covers the differential device 14 from the rear is attached to the housing 16 behind the housing 16. It has been. The cover 18 is provided with cooling fins 19.

  The rear differential device 14 is driven by a pinion drive shaft (drive shaft) 11 connected to the rear end portion of the propeller shaft 10, a pinion gear 20 formed at the rear end portion of the pinion drive shaft 11, and the pinion gear 20. A ring gear 22 and a differential case 24 attached to the ring gear 22. From the side of the rear differential device 14, a drive shaft 26 extends through each gear of the differential so as to drive a wheel (not shown).

Next, the drive device 12 includes a motor (motor generator) 30, a planetary gear 32, and an intermittent device (multi-plate brake) 34.
The motor 30 includes a stator 36 and a rotor 38, and the rotor 38 is connected to the sun gear 40 of the planetary gear 32.

As a planetary gear, several pinion gears 42 are provided around the sun gear 40, and a carrier 48 is fixed to these pinion gears 42 via a bearing 44 and a pinion shaft portion 46. The carrier 48 can be rotated by a bearing 44 and a pinion shaft 46, and the pinion gear 42 revolves.
The carrier 48 is connected to the pinion drive shaft 11 that is a drive shaft, and the rotational power of the rotor 38 and the sun gear 40 is decelerated by the pinion gear 42 to transmit the power to the pinion drive shaft 11.

  A ring gear 50 is provided around the pinion gear 42. When the ring gear 50 is fixed, the rotation of the sun gear 40 is transmitted to the pinion gear 42 and power is transmitted to the pinion drive shaft 11. However, if the ring gear 50 is not fixed, the pinion gear 42 and the ring gear 50 idle. No power is transmitted to the pinion drive shaft 11.

  Thus, the intermittent device 34 engages or disengages the ring gear 50 with the housing 16 in order to fix or unfix the ring gear 50. The interrupting device 34 is fixed to the outer periphery of the ring gear 50, is provided on the housing 16 side with two rotating plates 52 that rotate together with the ring gear 50, and can move in the axial direction but cannot rotate in the rotating direction. A fixing plate 54 and a retaining plate 56. The fixing plate 54 and the retaining plate 56 are urged in the axial direction by a snap ring (not shown) and a disc spring (not shown).

  A piston 60 is engaged with the fixed plate 54, and the fixed plate 52 is pressed in the axial direction by the piston 60 and moves only in the axial direction. A hydraulic chamber 62 is formed between the piston 60 and the front case 17, and the piston 60 is pressed by the hydraulic pressure. The piston 60 is normally urged toward the hydraulic chamber 62 by a return spring (not shown).

When the piston 60 is pressed by hydraulic pressure, the disc spring is pressed, and the disc spring presses the fixed plate 54 toward the retaining plate 56, whereby the fixed plate 54 and the rotating plate 52 of the ring gear 50 are engaged. It comes to match. In other words, the fixed plate 54 serves as a friction plate, and prevents the fixed plate 50 of the ring gear 50 from rotating when engaged. On the other hand, when the piston 60 is not pressed by hydraulic pressure, the fixed plate 54 and the rotating plate 52 of the ring gear 50 are disengaged.
The rotary plate 52, the fixed plate 54, the retaining plate 56, the piston 60, the hydraulic chamber 62, and the like constitute a multi-plate brake portion 64.

Next, referring to FIGS. 2 and 3, a water gallery which is a part of the cooling system of the drive device 12 according to the embodiment of the present invention will be described. FIG. 3 is a cross-sectional view taken along line III-III in FIG.
As shown in FIGS. 2 and 3, the driving device 12 has a cooling water channel formed in the housing 16. Specifically, a first water gallery 70 is formed between the motor 30 in the housing 16 and the differential device 14, and a second water gallery 72 is formed on the outer peripheral side of the motor 30.

  More specifically, in the first water gallery 70, the cooling water flows from the inlet portion 70a, and the cooling water that has taken the heat of the motor 30 and the differential device 14 flows out from the outlet portion 70b. . The first water gallery 70 is provided between the motor 30 and the differential device 14 in the housing 16 that houses the motor 30 and the differential device 14, and makes one round around the pinion gear 20 of the differential device 14. It is arranged to do.

  According to the first water gallery 70, it is possible to make it difficult for heat generated by the operation of the differential device 14 to be transmitted to the motor 30, thereby suppressing a decrease in output efficiency due to the motor 30 becoming high temperature. I can do it. Further, the differential device 14 itself can be cooled by the first water gallery 70 as described above, and the cooling efficiency of the entire drive device 12 in which the motor 30 and the differential device 14 are integrated is also considered while placing importance on the cooling of the motor 30. It can be raised.

  In addition, the first water gallery 70 is disposed around the pinion gear 20 of the differential device 14, and the pinion gear 20 is substantially between the motor 30 and the differential device 14, so that the first water gallery 70 is arranged around the pinion gear 20. The drive device 12 can be cooled more reliably by the provided first water gallery 70.

  Further, in the second water gallery 72, the cooling water flows from the inlet portion 72a, and the cooling water deprived of the heat of the motor 30 flows out from the outlet portion (not shown). The second water gallery 72 is provided so as to make one turn around the motor 30, and can suppress a decrease in output efficiency due to the motor 30 becoming high temperature.

Next, the configuration of the cooling system according to the embodiment of the present invention will be described with reference to FIG. FIG. 4 is a conceptual diagram showing the configuration of the cooling system of the drive device according to the embodiment of the present invention.
As shown in FIG. 4, the drive device 12 is supplied with cooling water from a water pump (cooling water pump) (W / P) 80, and the supplied cooling water is supplied by a flow control valve (flow rate adjusting valve) 82. The first water gallery 70 is distributed through the first flow path 100, and is distributed to the second water gallery 72 through the second flow path 102. The cooling water having the heat flowing out from the first water gallery 70 and the second water gallery 72 is sent to a radiator (heat radiator) 86 to be cooled. A cooling fan 88 that cools the cooling water in the radiator 86 is attached to the radiator 86.

Next, the configuration of the flow control valve according to the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic view showing a flow control valve according to an embodiment of the present invention.
First, as shown in FIG. 5, the flow control valve 82 includes a solenoid valve 90, a rod 92, a spool 94, a positioning cylindrical portion 96, and a spring 98.

  As shown in FIG. 5, the spool 94 is biased toward the spring 98 at the biased position where the current flows through the solenoid valve 90, and at this biased position, the spool 94 is in the first flow path 100. And the second flow path 102 is closed. Therefore, in this energized position, the cooling water flows through the first flow path 100 communicated between the motor 30 and the differential device 14 and flows into the first water gallery 70 between the motor and the differential device. It has become.

  On the other hand, although not shown, in an initial position where no current flows through the solenoid valve 90, the spool 94 is urged toward the solenoid valve 90 by the spring 98, and the positioning cylindrical portion 96 abuts on the solenoid valve 90, Positioning is done. In this initial position, the spool 94 closes the first flow path 100 and opens the second flow path 102. Therefore, in this initial position, the cooling water flows into the second water gallery 72 on the motor 30 side through the second flow path 102 communicating with the motor 30 side.

  The flow control valve 82 can be stopped at an arbitrary position between the initial position and the biasing position by controlling the current value of the solenoid valve 90. Therefore, the amount of cooling water discharged from the water pump 80 is in accordance with the position of the spool 94 and the second flow channel communicating with the first flow channel 100 and the second water gallery 72 communicating with the first water gallery 70. Cooling water having a predetermined flow rate can be distributed to each flow path 102.

  Since the cooling water can be arbitrarily distributed in this way, the first water gallery 70 provided between the motor 30 and the differential device 14 and the first provided around the motor 30 according to the traveling state. The flow rate distribution of the cooling water with the 2-water gallery 72 can be adjusted, and the flow rate of the cooling water can be made appropriate according to the running state.

  Next, the control content of the flow control valve according to the embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a flowchart showing the control contents of the flow control valve according to the embodiment of the present invention, and FIG. 7 is a map for determining the amount of cooling water to flow to the second water gallery on the outer periphery of the motor according to the motor temperature. FIG. 8 is a map for determining the amount of cooling water flowing to the first water gallery between the motor and the differential according to the difference between the motor temperature and the differential oil temperature, and FIG. 9 shows the rotation speed of the water pump. It is a map for determining according to the amount of cooling water of a water pump. In FIG. 6, S represents each step.

First, in S1 of FIG. 6, vehicle speed, motor temperature Tm, and differential oil temperature Td are detected. Next, in S2, the flow rate Qm of the cooling water to the second water gallery 72 provided around the motor 30 corresponding to the motor temperature Tm detected in S1 is determined and read by Map1 shown in FIG.
Next, in S3, it is detected whether or not the oil temperature Td of the differential 14 is equal to or higher than a predetermined temperature Td0. When the oil temperature Td is not equal to or higher than the predetermined temperature Td0, the process proceeds to S4, and cooling that flows to the first water gallery 70 provided between the motor 30 and the differential device 14 is performed on the assumption that the differential 14 need not be cooled. Set the water volume Qmd to 0.

  In S3, when the oil temperature Td is equal to or higher than the predetermined temperature Td0, the process proceeds to S5, and whether or not the difference (Td−Tm) between the oil temperature Td of the differential 14 and the motor temperature Tm is equal to or higher than a predetermined value Tmd1 ( If the oil temperature Td of the differential 14 is higher than the motor temperature Tm), or whether the difference (Td−Tm) between the oil temperature Td of the differential 14 and the motor temperature Tm is equal to or less than a predetermined value Tmd2 (oil of the differential 14 When the temperature Td is lower than the motor temperature Tm). If the difference is not greater than Tmd1 and not less than Tmd2, the difference between the oil temperature Td of the differential 14 and the motor temperature Tm is small, so that the difference 14 is transmitted from the differential 14 to the motor 30 or from the motor 30 to the differential 14. Assuming that the amount of heat to be generated is small, the process proceeds to S4, where the cooling water amount Qmd flowing to the first water gallery 70 provided between the motor 30 and the differential device 14 is set to zero.

  In S5, if the difference is equal to or greater than Tmd1, or if the difference is equal to or less than Tmd2, the process proceeds to S6, and it is determined whether or not the motor temperature Tm is equal to or less than a predetermined temperature Tm0. When the motor temperature Tm is equal to or lower than the predetermined temperature Tm0, the process proceeds to S4, and the cooling water amount Qmd flowing to the first water gallery 70 provided between the motor 30 and the differential device 14 is set to zero. This is to prevent the heat transfer from the differential 14 to the motor 30 from being suppressed. That is, the heat of the differential 14 is intentionally transferred to the motor 30 so that the motor 30 reaches a temperature at which the efficiency is increased. It is going to rise.

  Proceeding to S6, if the motor temperature Tm is not equal to or lower than the predetermined temperature Tm0, proceeding to S7, it is determined whether or not the propeller shaft 10 is driven by the engine 2 and the interrupting device 34 is OFF. When the propeller shaft 10 is driven by the engine 2 and the interrupting device 34 is not OFF, the temperature difference between the differential 14 and the motor 30 is difficult to increase, and the differential 14 to the motor 30 or Assuming that it is not necessary to prevent the heat transfer from the motor 30 to the differential 14, the process proceeds to S <b> 4, and the cooling water amount Qmd flowing to the first water gallery 70 provided between the motor 30 and the differential device 14 is set to 0. To do.

  In S7, when the propeller shaft 10 is driven by the engine 2 and the intermittent device 34 is OFF, the temperature of the differential 14 becomes higher than the temperature of the motor 30, and the temperature difference between them becomes large. Assuming that the state is present, the process proceeds to S8. In S8, the amount of cooling water Qmd flowing to the first water gallery 70 provided between the motor 30 and the differential device 14 is determined according to the difference between the motor temperature Tm and the differential oil temperature Td by Map2 shown in FIG. And read. In Map 2, the larger the temperature difference between the motor temperature Tm and the differential oil temperature Td, the larger the amount of cooling water Qmd that flows to the first water gallery 70. Therefore, even if the temperature difference is large, the differential 14 to the motor 30. It is possible to more reliably suppress the heat transfer to or the heat transfer from the motor 30 to the differential 14.

Next, proceeding to S9, the flow rate Qm of cooling water to the second water gallery 72 provided around the motor 30 read in S2 and the motor 30 read in S8 and the differential device 14 are provided. The total amount Qw / p of cooling water to be passed by the water pump 80 is determined by adding the amount of cooling water Qmd to be passed to the first water gallery 70.
Next, proceeding to S10, the rotational speed Nw / p of the water pump 80 for obtaining the total amount Qw / p of the cooling water flowing by the water pump 80 determined in S9 is read. Next, in S11, the water read in S9 is read. The water pump 80 is controlled so that the rotation speed Nw / p of the pump 80 is reached.

Next, it progresses to S12 and it is determined from the vehicle speed detected by S1 whether the vehicle has stopped. When the vehicle is stopped, the process proceeds to S13, and it is determined whether or not the coolant temperature Tw of the water pump 80 is equal to or higher than a predetermined temperature Tw0.
In S12 and S13, when the vehicle stops and the cooling water temperature Tw of the water pump 80 is equal to or higher than the predetermined temperature Tw0, the process proceeds to S14 to further cool the cooling water of the water pump 80, and the cooling fan 88 Is operated to cool the cooling water in the radiator 86.

  On the other hand, in S12, when the vehicle is not stopped, that is, when traveling, the radiator 86 hits the traveling wind, so that it is not particularly necessary to operate the cooling fan 88. Proceed to S15. In S13, even when the cooling water temperature Tw of the water pump 80 is not equal to or higher than the predetermined temperature Tw0, the cooling water temperature Tw is small, so that it is not particularly necessary to operate the cooling fan 88. Proceed to

  Next, in S15, the flow rate Qm of the cooling water to the second water gallery 72 provided around the motor 30 and the first water gallery provided between the motor 30 and the differential device 14 read in S8. The flow rate control valve 82 is controlled so as to obtain the cooling water amount Qmd to be flowed to 70 respectively.

Next, the operation and effect of the above-described embodiment will be described with reference to FIG. FIG. 10 is a diagram mainly showing changes in motor temperature and differential temperature together with the prior art according to an embodiment of the present invention.
As shown in FIG. 10, in the portion indicated by the symbol A, the cooling water amount Qmd flows through the first water gallery 70 provided between the motor 30 and the differential device 14, so that heat is transferred from the motor 30 to the differential 14. Therefore, the temperature of the differential 14 can be made lower than that of the prior art.

  In the portion indicated by the symbol B, the amount of cooling water Qmd flows through the first water gallery 70 provided between the motor 30 and the differential device 14, so that heat is prevented from being transferred from the differential 14 to the motor 30. The temperature of the motor 30 can be lowered. On the other hand, the temperature of the differential 14 can also be made lower than that of the prior art by such a water amount Qmd. And in the area | region like the code | symbol B, it turns out that the temperature of the motor 30 can fully be lowered | hung even if the cooling water poured into the 2nd water gallery 72 by the side of a motor is set to zero.

  In the portion indicated by the symbol C, the temperature of the motor becomes high in the prior art and sufficient energy regeneration by the motor cannot be obtained, but in the present embodiment, the first provided between the motor 30 and the differential device 14. By flowing the amount of cooling water Qmd through the one water gallery 70, the heat of the differential 14 can be prevented from being transmitted to the motor 30 and the temperature of the motor 30 can be kept low, so that sufficient energy regeneration is possible.

  Further, in the portion indicated by reference sign D, the temperature of the motor becomes high in the prior art and sufficient acceleration force by the motor cannot be obtained, but in this embodiment, it is provided between the motor 30 and the differential device 14. By flowing the cooling water amount Qmd through the first water gallery 70, the heat of the differential 14 can be prevented from being transmitted to the motor 30 and the temperature of the motor 30 can be kept low. Can be obtained.

  As described above, in the embodiment of the present invention, the water gallery 70 is provided between the motor 30 and the differential 14, and when the temperature of the differential 14 is higher than a predetermined temperature, the water gallery 70 is supplied with cooling water. Since it is made to flow, while the temperature of the differential 14 can be reduced, the transfer of heat from the differential 14 to the motor 30 can be prevented. As a result, the temperature rise of the motor 30 can be prevented and the output efficiency of the motor 30 can be increased.

Further, in the present embodiment, when there is a large temperature difference where heat is largely transferred from the differential 14 to the motor 30, that is, when the temperature of the differential 14 is higher than the temperature of the motor 30, Since the cooling water is allowed to flow through the water gallery 70 provided between the differential 14 and the heat, the heat transfer from the differential 14 to the motor 30 can be more reliably suppressed, and the temperature rise of the motor 30 can be prevented.
On the contrary, in the present embodiment, when there is a large temperature difference where heat is largely transferred from the motor 30 to the differential 14, that is, when the temperature of the motor 30 is higher than the temperature of the differential 14. Since the cooling water is caused to flow through a water gallery 70 provided between the motor 14 and the differential 14, the heat transfer from the motor 30 to the differential 14 can be more reliably suppressed and the temperature increase of the differential 14 can be prevented.

Furthermore, in the present embodiment, the larger the temperature difference between the temperature of the differential 14 and the temperature of the motor 30, the more cooling water flowing through the water gallery 70 provided between the motor 30 and the differential 14 is increased. In addition, the heat transfer from the differential 14 to the motor 30 can be suppressed, and the temperature rise of the motor 30 can be prevented.
Conversely, in this embodiment, the greater the temperature difference between the temperature of the motor 30 and the differential 14, the greater the amount of cooling water flowing through the water gallery 70 provided between the motor 30 and the differential 14. Heat transfer from the motor 30 to the differential 14 can be reliably suppressed, and the temperature rise of the differential 14 can be prevented.

  Furthermore, in this embodiment, when the temperature of the motor 30 is lower than a predetermined temperature, for example, a temperature at which the output efficiency of the motor 30 is reduced, the cooling water is not allowed to flow to the water gallery 70 between the motor 30 and the differential 14. The heat of the differential 14 is intentionally transmitted to the motor 30 to raise the temperature of the motor 30 and increase the output efficiency of the motor.

  Furthermore, in the embodiment of the present invention, the cooling fan 88 is operated when the vehicle is stopped when the traveling wind does not hit the radiator, so that the cooling water flowing through the water gallery 70 between the motor 30 and the differential 14 is cooled more reliably. As a result, the heat transfer from the differential 14 to the motor 30 can be suppressed more reliably, and the temperature rise of the motor 30 can be prevented.

  Furthermore, in the embodiment of the present invention, when the output of the engine 2 is transmitted to the propeller shaft (drive shaft) 10 and the motor 30 and the propeller shaft (drive shaft) 10 are not connected, that is, the temperature of the differential 14. Rises, and more reliably suppresses heat transfer from the differential 14 to the motor 30 in the travel mode in which the difference between the temperature of the differential 14 and the temperature of the motor 30 that is basically stopped is large. Thus, the temperature rise of the motor 30 can be prevented.

It is the schematic which shows the structure of the drive unit to which the vehicle drive device by embodiment of this invention is applied. It is sectional drawing which looked at the vehicle drive device by embodiment of this invention from the side. It is sectional drawing seen along the III-III line of FIG. It is a conceptual diagram which shows the structure of the cooling system of the drive device by embodiment of this invention. It is the schematic which shows the flow control valve by embodiment of this invention. It is a flowchart which shows the control content of the flow control valve by embodiment of this invention. It is a map for determining the amount of cooling water sent to the 2nd water gallery in the perimeter of a motor according to motor temperature. It is a map for determining the amount of cooling water to flow to the first water gallery between the motor and the differential according to the difference between the motor temperature and the differential oil temperature. It is a map for determining the rotation speed of a water pump according to the amount of cooling water of a water pump. It is a diagram which shows the change of motor temperature and differential temperature mainly with the prior art by embodiment of this invention.

Explanation of symbols

10 Propeller shaft (drive shaft)
12 Drive device 14 Rear differential device 16 Housing 30 Motor 34 Intermittent device 70 First water gallery 72 Second water gallery 80 Water pump 82 Flow control valve 86 Radiator 88 Cooling fan

Claims (6)

A vehicle drive having a motor provided on a drive shaft for driving wheels via the drive shaft and a differential provided at a downstream end of the drive shaft, wherein the motor and the differential are integrated. A device,
A housing for accommodating the motor and the differential so as to be integrated;
A water gallery provided in the housing for cooling the drive device by circulating cooling water;
A radiator that cools the cooling water;
A cooling water pump for circulating cooling water;
Cooling water control means for controlling the cooling water pump;
Differential temperature detection means for detecting the temperature of the differential, and
At least a part of the water gallery is provided between the motor and the differential,
The cooling water control means operates the cooling water pump when the temperature of the differential detected by the differential temperature detection means is higher than a predetermined temperature, and a water gallery provided between the motor and the differential. Cooling control is performed so that cooling water flows through the vehicle drive device. Furthermore, it has a motor temperature detecting means for detecting the temperature of the motor,
The vehicle according to claim 1, wherein the cooling water control unit performs the cooling control when a temperature of the differential detected by the differential temperature detection unit is higher than a temperature of the motor detected by the motor temperature detection unit. Drive device.   The cooling water control means increases the temperature difference between the differential temperature detected by the differential temperature detection means and the motor temperature detected by the motor temperature detection means. The vehicle drive device according to claim 2, wherein the cooling water pump is operated so that the amount of cooling water flowing through a water gallery provided between the differential and the differential increases.   When the temperature of the motor detected by the motor temperature detecting means is lower than a predetermined temperature, the cooling water control means does not perform the cooling control and cools to a water gallery provided between the motor and the differential. The vehicle drive device according to claim 1, wherein the operation of the cooling water pump is suppressed so that water does not flow. And a cooling fan for cooling the radiator.
5. The vehicle drive device according to claim 1, wherein the cooling water control unit performs the cooling control and operates the cooling fan when the vehicle is stopped. 6. Furthermore, an engine that is connected to the drive shaft and drives a wheel via the drive shaft, and an intermittent means that connects or disconnects the motor and the drive shaft,
The cooling water control means performs the cooling control when the output of the engine is transmitted to the drive shaft and the motor and the drive shaft are not connected by the intermittent means. The vehicle drive device according to claim 1.

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