JP2017118773A - Oil cooling system for vehicle driving motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil cooling system for a vehicle driving motor which reduces an electric oil pump in size, reduces costs, and can suppress electric power consumption.SOLUTION: An oil cooling system for a vehicle driving motor comprises: the vehicle driving motor having an oil sump storing lubricating oil therein; a first electric oil pump pressure-feeding the lubricating oil into the vehicle driving motor and lubricating it while sucking the lubricating oil from the oil sump; a second electric oil pump being provided in parallel to the first electric oil pump, pressure-feeding the lubricating oil into the vehicle driving motor and lubricating it while sucking the lubricating oil from the oil sump; a temperature sensor measuring a temperature of the lubricating oil; and a control device controlling activation of the first electric oil pump and the second electric oil pump on the basis of measurement results of the temperature sensor. Further, torque output capability of the first electric oil pump is greater than that of the second electric oil pump.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an oil cooling system for an electric motor for driving a vehicle.

  A vehicle driving motor mounted on an electric vehicle generates heat with operation and becomes high temperature, and is cooled using a cooling system. As a cooling system for cooling a vehicle drive motor, an oil cooling system is known in which lubricating oil cooled by an oil cooler is supplied to the inside of the vehicle drive motor by an electric oil pump and cooled. An oil cooling system that cools a motor for driving a vehicle with lubricating oil has an advantage that the bearing can be lubricated with the lubricating oil while being cooled.

JP-A-6-98417

  The viscosity of the lubricating oil increases remarkably from about 10 ° C. toward low temperatures. Therefore, if the torque of the electric oil pump driving motor is not sufficient with respect to the viscosity of the lubricating oil, the discharge amount of the lubricating oil is insufficient, and it is considered that the bearing in the motor for driving the vehicle runs out of oil. Therefore, the electric oil pump driving force requires a high torque to cope with a low temperature.

  Generally, the viscosity of the lubricating oil varies depending on the oil type, but if the viscosity at 10 ° C. is 1, the viscosity increases by about 1.7 to 1.8 times at 0 ° C., and about 3 times at −10 ° C. , At about −30 ° C., it increases about 13 to 18 times. The need for driving overcoming this viscous resistance increases the size of the electric oil pump.

  On the other hand, the electric oil pump needs to send a large amount of lubricating oil to the vehicle drive motor in order to cool the vehicle drive motor when the temperature of the vehicle drive motor becomes high. When the internal temperature of the motor for driving the vehicle increases, it is necessary to increase the amount (flow rate) of the lubricating oil. At that time, the oil is warmed and the oil temperature is well above 10 ° C. Therefore, the absolute value of the oil viscosity is Since it is small and the viscosity difference between 10 ° C. and 150 ° C. is small, it does not require a large driving force as at low temperatures. In other words, since a small amount is sufficient at low temperatures, the driving force of the electric oil pump for supplying lubricating oil to the bearings, and at high temperatures, a large amount of oil transport (flow rate) is required for internal cooling of the electric motor. A large number of rotations is required.

  For this reason, in the past, a high-output type electric oil pump that satisfies both low temperature and high temperature requirements was used, and both the low temperature characteristics and the high temperature characteristics were provided. Has become larger, making it difficult to mount on vehicles.

  An object of the present invention is to provide an oil cooling system for an electric motor for driving a vehicle that can reduce the size of an electric oil pump, reduce costs, and suppress power consumption.

  In order to solve the above-mentioned problems, the present invention has an oil cooling system for a vehicle driving motor configured as follows. An oil cooling system for a vehicle driving motor includes a vehicle driving motor having an oil reservoir for storing lubricating oil therein, and a first lubricating oil that is sucked from the oil reservoir and pumped into the vehicle driving motor for lubrication. An electric oil pump and a second electric oil pump that are provided in parallel with the first electric oil pump and suck the oil from the oil reservoir and pressurize and lubricate the lubricating oil inside the vehicle driving motor, and measure the temperature of the lubricating oil A temperature sensor that controls the operation of the first electric oil pump and the second electric oil pump based on the measurement result of the temperature sensor. The torque output capability of the first electric oil pump is greater than that of the second electric oil pump.

  ADVANTAGE OF THE INVENTION According to this invention, the electric oil pump can be reduced in size, cost can be reduced, and the oil cooling system of the vehicle drive motor which can reduce the electric power consumption of an electric oil pump can be provided.

The perspective view which shows the vehicle provided with the oil cooling system of the motor for a vehicle drive of one Embodiment concerning this invention. The perspective view which shows the electric motor for a vehicle drive. The fragmentary sectional view which shows the electric motor for a vehicle drive. Sectional drawing which shows the motor for a vehicle drive. The block diagram which shows the oil cooling system of the electric motor for a vehicle drive. Sectional drawing which shows the motor for a vehicle drive of other embodiment.

  An oil cooling system for an electric motor for driving a vehicle according to an embodiment of the present invention will be described. FIG. 1 shows a vehicle 10 provided with an oil cooling system for a vehicle driving motor. The vehicle 10 includes a front wheel 12, a rear wheel 14, an electric motor 16, and a cooling device 18 that cools the electric motor 16 with lubricating oil. The oil cooling system for the motor for driving the vehicle basically refers to a combination of the motor 16 and the cooling device 18.

  The electric motor 16 is a vehicle driving electric motor as a driving source for traveling of the vehicle 10, and includes a rotating shaft 26 at substantially the center as shown in FIG. Hereinafter, regarding the oil cooling system of the motor for driving the vehicle, the side on which the rotating shaft 26 of the motor 16 is provided is the front of the motor 16 and the opposite is the rear, and the oil cooling system of the motor for driving the vehicle is attached to the vehicle 10. The up-down direction of the vehicle 10 in the state in which it is being used will be described as the up-down direction of the electric motor 16 and the cooling device 18.

  As shown in FIGS. 3 and 4, the electric motor 16 includes a casing 30, a stator 32, and a rotor 34. The casing 30 includes a substantially cylindrical outer peripheral wall 36, a front wall 38 provided in front of the outer peripheral wall 36, a rear wall 40 provided behind the outer peripheral wall 36, and an oil reservoir 42. . FIG. 3 is a partial cross-sectional view taken along the line F3-F3 in FIG. 4 is a cross-sectional view taken along a plane passing through the line F4-F4 in FIG.

  The rear wall 40 is formed integrally with the outer peripheral wall 36 behind the outer peripheral wall 36. The rear wall 40 is substantially flat and has a second bearing 62 that supports the rotating shaft 26 assembled thereto. An inlet 44 is provided in the upper part of the outer peripheral wall 36.

  The inflow port 44 is cylindrical and communicates with the guide portion 48. The guide portion 48 is provided on the upper portion of the outer peripheral wall 36. A cooling device 18 described later is connected to the upper part of the inflow port 44.

  The guide portion 48 includes a lateral passage 22 and a plurality of vertical holes 24. As shown in FIG. 3, the lateral passage 22 is formed inside the outer peripheral wall 36 in parallel with the rotation shaft 26 of the electric motor 16. The lateral passage 22 has a circular cross section and is formed from the front end surface of the casing 30 to the vicinity of the rear wall 40. The front end of the horizontal passage 22 opens at the front end of the casing 30. The opening in front of the lateral passage 22 is closed by a front wall 38 attached to the casing 30.

  A vertical hole 24 communicates with the horizontal passage 22. The vertical holes 24 are formed in the horizontal passage 22 at a predetermined interval. The vertical hole 24 is formed in a direction directly below the horizontal passage 22, and one end of the vertical hole 24 opens to the ceiling surface 46 of the casing 30.

  In addition, you may change suitably the installation space | interval and diameter of the vertical hole 24 with the center and the edge part of the casing 30, for example. Further, instead of the horizontal passage 22 and the vertical hole 24, a pipe communicating with the inlet 44 may be provided on the inner surface of the outer peripheral wall 36. Perforations for opening the pipes are appropriately provided on the side surfaces of the pipes as with the vertical holes 24. An oil sump 42 is provided at the lower portion of the outer peripheral wall 36.

  The oil sump 42 has a substantially rectangular parallelepiped shape with a bottom plate 54 at the bottom. A temperature sensor 58 is provided inside the oil sump 42. The temperature sensor 58 is connected to the control device 100 (see FIG. 5) via a signal line, measures the temperature of the lubricating oil stored in the oil sump 42, and transmits the value to the control device 100. The bottom plate 54 is provided with an outlet 56. A cooling device 18 to be described later is connected to the outlet 56.

  The front wall 38 is attached to the front of the outer peripheral wall 36 with screws or the like. A first bearing 60 that supports the rotary shaft 26 is assembled to the front wall 38. The outer peripheral wall 36, the front wall 38 and the rear wall 40 form a basically sealed space inside the casing 30. A stator 32 is provided inside the casing 30.

  The stator 32 is cylindrical, and is fixed to the casing 30 with a predetermined gap a from the inner surface of the outer peripheral wall 36. A rotor 34 is provided inside the stator 32.

  The rotor 34 has a rotation shaft 26 at the center, and is provided concentrically with the stator 32. The rotating shaft 26 is supported by the first bearing 60 and the second bearing 62. The front end of the rotating shaft 26 passes through the first bearing 60 and protrudes forward of the electric motor 16. The rotating shaft 26 is connected to at least the front wheel 12 of the vehicle 10 via a differential gear or the like. The electric motor 16 may be connected to the rear wheel 14 or both the front wheel 12 and the rear wheel 14 instead of the front wheel 12 of the vehicle 10.

  The first bearing 60 is assembled to the front wall 38. The first bearing 60 is assembled in the same plane as the inner surface of the front wall 38. The inner surface side of the casing 30 of the first bearing 60 has no cover or the like, and the rolling elements between the outer ring and the inner ring are exposed.

  The second bearing 62 is assembled to the rear wall 40. The second bearing 62 is assembled in the same plane as the inner surface of the rear wall 40. The inner surface side of the casing 30 of the second bearing 62 has no cover or the like, and the rolling elements between the outer ring and the inner ring are exposed.

  Next, the cooling device 18 will be described. FIG. 5 shows the configuration of the cooling device 18. As shown in FIG. 5, the cooling device 18 includes a first electric oil pump 72, a second electric oil pump 74, an oil cooler 76, an on-off valve 80, and a control device 100. The cooling device 18 is provided between the outlet 56 of the electric motor 16 and the inlet 44 with the outlet 56 of the electric motor 16 as the upstream side and the inlet 44 as the downstream side.

  One end of the first oil feeding pipe 70 is connected to the outlet 56. The other end of the first oil feeding pipe 70 is provided with a branching member 84 branched into two outflow pipes. One outflow pipe of the branch member 84 is connected to the inlet of the first electric oil pump 72. The other outflow pipe of the branch member 84 is connected to the inlet of the second electric oil pump 74.

  The first electric oil pump 72 is a high torque electric oil pump including a pump driving electric motor, a reduction gear, and a pump unit. When the power is turned on, the pump driving motor rotates the rotating shaft at a predetermined rotational speed. The speed reducer is connected to the rotating shaft of the pump driving electric motor, reduces the rotation of the rotating shaft by the gear train, and drives the pump unit. The pump unit operates at a high torque when the rotation speed is reduced by the speed reducer. As a result, the first electric oil pump 72 can, for example, reliably convey lubricating oil having a low temperature and high viscosity (conveying oil with pressure).

  The pump drive motor built in the first electric oil pump 72 is generally a small motor. Although it is a small motor, since the reduction gear is interposed, a large torque can be obtained as the output shaft torque of the reduction gear. On the other hand, since the engine speed is low, the oil discharge amount is not large. However, since the purpose is to supply lubricating oil to the bearings of the motor for driving the vehicle, the function and performance are satisfied in this respect. Moreover, since it is a small motor, power consumption is small.

  The second electric oil pump 74 is an electric oil pump including a pump driving electric motor and a pump unit. When the power supply is turned on, the pump driving motor rotates at a predetermined rotation speed, and the pump unit is driven by the rotation shaft of the pump driving motor. The second electric oil pump 74 has a torque lower than the pumping torque of the first electric oil pump 72 and is unsuitable for pumping highly viscous lubricating oil. On the other hand, the second electric oil pump 74 is capable of sending more lubricating oil having a lower viscosity than the delivery amount per hour that the first electric oil pump 72 has.

  The outflow port of the first electric oil pump 72 and the outflow port of the second electric oil pump 74 are respectively connected to the two inflow pipes of the confluence member 86. The joining member 86 joins two inflow pipes into one outflow pipe.

  The outflow pipe of the junction member 86 is connected to the inlet of the oil cooler 76. The oil cooler 76 is a heat exchanger for lubricating oil including a plurality of tubes and fins. The outlet of the oil cooler 76 is connected to the inlet 44 of the electric motor 16 via the second oil feeding pipe 82. The oil cooler 76 is provided with a bypass pipe 78. The bypass pipe 78 bypasses the oil cooler 76 and is opened and closed by an opening / closing valve 80 provided in the bypass pipe 78.

  A signal line from the control device 100 is connected to each actuator of the first electric oil pump 72, the second electric oil pump 74, and the on-off valve 80.

  Next, the operation and effect of the oil cooling system for the vehicle drive motor will be described. When the main switch of the vehicle 10 is turned on, the control device 100 reads the temperature of the lubricating oil stored in the oil reservoir 42 from the temperature sensor 58 and compares the read temperature of the lubricating oil with a threshold value. When the temperature of the lubricating oil is equal to or lower than the threshold value, control device 100 determines that electric motor 16 is in a low temperature state.

  When the accelerator pedal of the vehicle 10 is stepped on by the driver, the electric motor 16 is activated and the vehicle 10 starts running. Based on the determination result that the electric motor 16 is in a low temperature state, the control device 100 sends an operation signal to the first electric oil pump 72 to operate the first electric oil pump 72.

  The first electric oil pump 72 has a large torque and has a performance of pumping highly viscous lubricating oil. Accordingly, the lubricating oil having high viscosity at low temperature is sucked from the oil reservoir 42 through the first oil feeding pipe 70 by the operation of the first electric oil pump 72. The lubricating oil sucked from the oil reservoir 42 is pushed out from the outlet of the first electric oil pump 72. The on-off valve 80 is opened based on an operation signal from the control device 100 determined to be in a low temperature state. Therefore, the lubricating oil pushed out from the first electric oil pump 72 does not flow into the oil cooler 76 but flows into the second oil feeding pipe 82 through the bypass pipe 78. The lubricating oil is fed into the electric motor 16 from the inlet 44 through the second oil feeding pipe 82.

  Lubricating oil fed into the electric motor 16 from the inlet 44 passes through the lateral passage 22, appropriately passes through the vertical hole 24, falls to the outer periphery of the stator 32, flows down along the stator 32, and is fixed to the stator. It falls from the end part of the front-back direction of 32, and adheres to the rotating shaft 26. FIG. The lubricating oil adhering to the rotating shaft 26 reaches the first bearing 60 and the second bearing 62 through the rotating shaft 26 and lubricates the first bearing 60 and the second bearing 62.

  When the lubricating oil reaches the front wall 38 and the rear wall 40 of the electric motor 16, the lubricating oil flows down along the inner surfaces of the front wall 38 and the rear wall 40. A first bearing 60 and a second bearing 62 are provided on the front wall 38 and the rear wall 40, respectively. Therefore, the lubricating oil that has flowed down from the guide portion 48 along the front wall 38 and the rear wall 40 reaches the first bearing 60 and the second bearing 62 that support the rotating shaft 26 and lubricates the first bearing 60 and the like. To do. As described above, since the first electric oil pump 72 has a large torque, at low temperatures, the highly viscous lubricating oil is pumped into the electric motor 16 to reliably supply the lubricating oil to the first bearing 60 and the like.

  On the other hand, when the vehicle 10 continues to run, the temperature of the electric motor 16 rises due to heat generation. When the measurement result from the temperature sensor 58 exceeds the threshold value, the control device 100 determines that the electric motor 16 has reached a high temperature state. When determining that the electric motor 16 has reached a high temperature state, the control device 100 sends an operation signal to the second electric oil pump 74 to operate the second electric oil pump 74. In addition, the control device 100 sends an operation signal for closing to the on-off valve 80 and closes the bypass pipe 78.

  When the second electric oil pump 74 is activated, the second electric oil pump 74 sucks the lubricating oil from the oil reservoir 42 of the electric motor 16 through the first oil feeding pipe 70 and sends it out from the outlet. The lubricating oil sent out from the second electric oil pump 74 flows into the oil cooler 76, is cooled by heat exchange in the oil cooler 76, and is sent from the inlet 44 into the electric motor 16 through the second oil feeding pipe 82. It is.

  The lubricating oil sent to the electric motor 16 flows through the vertical holes 24 from the horizontal passages 22 and flows down onto the stator 32, thereby cooling the stator 32. Further, the lubricating oil that has cooled the stator 32 flows down from the front and rear ends of the stator 32 to the rotor 34, cools the rotor 34, reaches the rotating shaft 26, and lubricates the first bearing 60 and the like. Further, since the lubricating oil has a high temperature and low viscosity and the rotational speed of the rotor 34 is high, the lubricating oil easily scatters around, and the lubricating oil scattered around lubricates the first bearing 60 and the like. .

  Further, a part of the lubricating oil flowing into the casing 30 from the vertical hole 24 flows down the inner surfaces of the front wall 38 and the rear wall 40 in the same manner as the lubricating oil at a low temperature, and causes the first bearing 60 and the second bearing 62 to flow. Lubricate.

  The lubricating oil that has cooled the electric motor 16 flows down to the lower portion of the casing 30, and is stored and stored in the oil reservoir 42. The lubricating oil stored in the oil reservoir 42 is sucked again by the second electric oil pump 74 through the outlet 56 and cooled by the oil cooler 76 to cool the electric motor 16 again.

  The second electric oil pump 74 has a larger amount of lubricating oil delivered per hour than the first electric oil pump 72, and can cool the electric motor 16 with a large amount of lubricating oil. The lubricating oil has a low viscosity because of its high temperature, and the second electric oil pump 74 having a lower torque than the torque of the first electric oil pump 72 can sufficiently pump the lubricating oil. Further, since the second electric oil pump 74 has a small torque, the second electric oil pump 74 is operated with less electric power than when the lubricating oil is pumped by the electric oil pump having the same torque as the first electric oil pump 72.

  Compared with the electric pump of the prior art, the second electric oil pump 74 consumes less power because it does not have to serve to convey oil when the viscosity resistance of the oil increases at low temperatures. That is, since there is no role to convey oil with a large torque in a low speed rotation region, power consumption is small.

  Further, since the second electric oil pump 74 does not have a built-in speed reducer, if a large torque is output in the low-speed rotation region equivalent to the first electric oil pump 72 and an attempt is made to convey oil having a high viscosity, the current consumption However, since the first electric oil pump 72 is responsible for transporting oil when the viscosity is large, it is not necessary to supply a large current to the second electric oil pump 74 to move it. Few.

  As described above, in the oil cooling system for the motor for driving the vehicle, when the temperature of the electric motor 16 is low, the first electric oil pump 72 is operated and the highly viscous lubricating oil is pumped to the electric motor 16, and the first bearing 60. The second bearing 62 is lubricated to prevent the bearing from seizing. The first electric oil pump 72 does not have a large discharge amount per hour, but can supply a sufficient amount of lubricating oil to lubricate the first bearing 60 and the like. In addition, since it is not necessary to supply a large amount of lubricating oil to the first bearing 60 or the like at low temperatures, the first electric oil pump 72 can be reduced in size and the power consumption during operation can be reduced because the pumping amount is small. .

  If the first and second bearings 60 and 62 run out of lubricant, the risk of bearing burnout increases. Also, the amount of lubricating oil required for the bearing is small in terms of function and performance. Therefore, the first electric oil pump 72 may be small.

  On the other hand, when the temperature of the electric motor 16 is high, the second electric oil pump 74 operates and the electric motor 16 can be reliably cooled by a large amount of lubricating oil. When the temperature is high, the lubricating oil also has a high temperature, a low viscosity, and good fluidity. Therefore, the lubricating oil can be sufficiently pumped by the second electric oil pump 74 having a torque smaller than that of the first electric oil pump 72. And since the 2nd electric oil pump 74 has a torque smaller than the 1st electric oil pump 72, it can reduce in size and can reduce the power consumption at the time of an operation | movement from a small torque. In addition, when operating the second electric oil pump 74, it is preferable to stop the operation of the first electric oil pump 72 from the viewpoint of reducing power consumption.

  The first electric oil pump 72 has a design in which a reduction gear is combined with a small electric oil pump, and an output shaft of the reduction gear and a pump unit are coupled to each other. If you look at the output shaft of the reducer, the torque is large although the number of revolutions is low. That is, since the purpose is bearing lubrication, the amount of oil transported may be small.

  On the other hand, the main function of the second electric oil pump 74 is to cool the internal heat generation of the vehicle drive motor. Oil is also supplied to the front and rear bearings (first bearing 60 and second bearing 62) of the same motor that are arranged at the front and rear, but the main role is the cooling described above. The performance required for the second electric oil pump 74 is smaller than that of the first electric oil pump 72 because a large amount of oil transport is required in proportion to the amount of heat generated inside the electric motor. Not always. Generally speaking, it may be larger than the first electric oil pump 72. However, it is smaller than conventional electric oil pumps.

  Since the conventional electric oil pump does not have a reduction gear, a large driving force cannot be obtained. If a reduction gear is attached to a conventional electric oil pump, a high rotational speed cannot be obtained, and the amount of oil transport (flow rate) cannot be obtained. The method of combining the first electric oil pump 72 and the second electric oil pump 74 of the present invention is smaller, consumes less power, and is more economical than the conventional large electric oil pump.

  As described above, according to the oil cooling system for a vehicle driving motor, when the temperature of the motor 16 is low, the first electric oil pump 72 supplies lubricating oil to the first bearing 60 and the like, and the bearing seizes. When the temperature is high, the second electric oil pump 74 can supply a large amount of lubricating oil to the electric motor 16 to perform sufficient cooling, reducing the size of the oil pump, reducing power consumption, and to the vehicle 10. Can be improved.

  Next, an oil cooling system for an electric motor for driving a vehicle according to a second embodiment will be described. FIG. 6 shows an electric motor 17 used in the oil cooling system of this vehicle driving electric motor. As shown in FIG. 6, the electric motor 17 is provided with a guide portion 49 inside the casing 30. The guide portion 49 is formed by a groove provided from the inner surface of the outer peripheral wall 36 at the uppermost portion of the inner surface of the outer peripheral wall 36. The guide portion 49 has a predetermined width and is inclined in the front-rear direction with the opening 52 portion of the inflow port 44 as a vertex. The front of the guide portion 49 extends to the front wall 38 and the rear extends to the rear wall 40. Since the other structure of the electric motor 17 is the same as that of the electric motor 16 of 1st Embodiment, it attaches | subjects the same code | symbol and abbreviate | omits description.

  In the electric motor 17 of this embodiment, when highly viscous lubricating oil is fed from the inlet 44 at low temperatures, the lubricating oil flows back and forth along the inclination of the guide portion 49. Then, the lubricating oil that has reached the front wall 38 and the rear wall 40 flows down along the inner surfaces of the front wall 38 and the rear wall 40 and lubricates the first bearing 60 and the second bearing 62.

  In the electric motor 17, since the guide portion 49 is inclined, the lubricating oil flowing in from the opening 52 reliably reaches the front wall 38 and the rear wall 40 and lubricates the first bearing 60 and the second bearing 62. When the temperature is low, the viscosity of the lubricating oil is high and the oil flows down reliably along the guide portion 49. Further, since the lubricating oil only needs to be supplied to such an extent that the oil film of the bearing does not break, even the supply from the first electric oil pump 72 with a small amount of oil feeding can be sufficiently lubricated.

  On the other hand, when the temperature is high, the second electric oil pump 74 is activated and the lubricating oil is sent into the electric motor 17. In that case, since the lubricating oil has a large flow rate and a high flow rate, the lubricating oil is directly applied to the stator 32 from the opening 52 regardless of the guide portion 49, and the electric motor 17 can be cooled. The guide portion 49 is not limited to the groove portion provided on the inner surface of the outer peripheral wall 36, and may be formed by a hole provided in the outer peripheral wall 36. Further, it may be formed of an inclined bowl-shaped member immediately below the opening 52.

  According to the electric motor 17 of the second embodiment, the lubricating oil from the first electric oil pump 72 reaches the first bearing 60 and the like through the guide portion 49, and the bearing is reliably lubricated. When the temperature is high, the motor 17 is reliably cooled by the lubricating oil from the second electric oil pump 74.

  In addition, this invention is not restricted to the said embodiment, It can change suitably. For example, the number of openings 52 connected to the inflow port 44 is not limited to one, and a plurality of openings 52 may be provided.

  INDUSTRIAL APPLICABILITY The present invention can be used for an oil cooling system for a vehicle driving motor of an electric vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 16 ... Electric motor, 18 ... Cooling device, 22 ... Side passage, 24 ... Vertical hole, 26 ... Rotating shaft, 30 ... Casing, 32 ... Stator, 34 ... Rotor, 36 ... Outer wall, 38 ... Front Wall 40, rear wall 42, oil sump 44, inlet, 46 ceiling, 48 guide section 54 bottom plate 56 outlet 58 temperature sensor 60 first bearing 62 second Two bearings, 70 ... first oil feeding pipe, 72 ... first electric oil pump, 74 ... second electric oil pump, 76 ... oil cooler, 78 ... bypass pipe, 80 ... open / close valve, 82 ... second oil feeding pipe, 84 ... Branch member, 86... Junction member, 100.

Claims (4)

An electric motor for driving a vehicle having an oil reservoir for storing lubricating oil therein;
A first electric oil pump that sucks the lubricating oil from the oil reservoir and pressurizes and lubricates the lubricating oil into the vehicle driving motor;
A second electric oil pump that is provided in parallel with the first electric oil pump, sucks the lubricating oil from the oil reservoir, and pumps and lubricates the lubricating oil into the vehicle drive motor;
A temperature sensor for measuring the temperature of the lubricating oil;
A control device for controlling the operation of the first electric oil pump and the second electric oil pump based on the measurement result of the temperature sensor;
The oil cooling system for a motor for driving a vehicle has a torque output capability of the first electric oil pump larger than that of the second electric oil pump.   The oil cooling system for an electric motor for driving a vehicle according to claim 1, wherein the first electric oil pump is an oil pump having a reduced speed using a reduction gear. The vehicle drive motor includes a casing, a stator, a rotor, and a bearing.
The bearing is a bearing that is assembled to the casing and supports the rotor;
An inlet through which the lubricating oil from the first electric oil pump and the second electric oil pump flows into the upper part of the casing;
3. The motor for driving a vehicle according to claim 2, wherein the oil reservoir is provided at a lower portion of the casing and has an outlet through which the lubricating oil is sucked by the first electric oil pump and the second electric oil pump. Oil cooling system.   The oil cooling system for an electric motor for driving a vehicle according to claim 3, wherein the casing is provided with a guide portion that extends through the opening of the inflow port to just above the bearing.

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