Power transmission device

Abstract

The present invention provides a power transmission device. The power transmission device includes: a single oil pump configured to deliver oil; an electric motor; a lubricated component lubricated by oil; an oil circuit configured to supply oil delivered from the oil pump to the electric motor and the lubricated component; a flow rate adjustment unit configured to be provided in the oil circuit and to control the amount of oil supplied to the electric motor; and a control unit configured to control the flow rate adjustment unit.

Description

Technical Field

[0001] This disclosure relates to power transmission devices. Background Technology

[0002] For example, Japanese Patent Application Publication No. 2016-125629 discloses a transmission mounted on a vehicle. This transmission includes a first rotary motor, a second rotary motor, planetary gears, and an oil pump.

[0003] In the transmission described in Japanese Patent Application Publication No. 2016-125629, the oil pump operates at a higher frequency under lubrication requirements than under the requirements of the rotating motors. Furthermore, the workload required by the oil pump under the requirements of the rotating motors is greater than that required under lubrication requirements. To meet these requirements, the oil pump needs to be driven at a frequency that meets both the requirements of the rotating motors and the lubrication requirements. Therefore, the workload (power consumption) of the oil pump increases. Summary of the Invention

[0004] Therefore, this disclosure provides a power transmission device that can reduce the workload of the oil pump.

[0005] This disclosure relates to a power transmission device comprising a single oil pump, an electric motor, a lubricated component, an oil passage, a flow rate adjustment unit, and a control unit. The single oil pump is configured to deliver oil, and the lubricated component is lubricated by the oil. The oil passage is configured to supply the oil delivered from the oil pump to the electric motor and the lubricated component. The flow rate adjustment unit is configured to be provided in the oil passage and to adjust the amount of oil supplied to the electric motor. The control unit is configured to control the flow rate adjustment unit.

[0006] According to the power transmission device described above, since the control unit can adjust the oil supply to the motor, for example, by increasing the oil supply to the motor, the motor can be effectively cooled, thus reducing the frequency of cooling requirements for the motor. Therefore, the workload of the oil pump can be reduced.

[0007] According to the power transmission device of this disclosure, the oil circuit may also include: a first oil circuit configured to supply oil from the oil pump to the electric motor; and a second oil circuit configured to branch off from the first oil circuit and supply oil from the oil pump to the lubricated component. Furthermore, the flow adjustment unit may be provided at the junction of the first oil circuit and the second oil circuit, between the first oil circuit and the electric motor.

[0008] According to the power transmission device with the above structure, since a flow adjustment unit is provided on the downstream side of the connection between the first oil circuit and the second oil circuit in the first oil circuit, the amount of oil supplied to the motor can be adjusted more accurately.

[0009] According to the power transmission device of the present disclosure, the control unit may also be configured to control the opening degree of the flow adjustment unit based on the temperature of the electric motor.

[0010] According to the power transmission device with the above structure, the control unit can also be configured to increase the opening degree of the flow adjustment unit when the temperature of the motor is above the high reference temperature.

[0011] According to the power transmission device of the present disclosure, the control unit may also be configured to control the opening degree of the flow rate adjustment unit based on the temperature of the oil flowing into the electric motor.

[0012] According to the power transmission device of the present disclosure, the control unit may also be configured to control the opening degree of the flow adjustment unit based on the pressure around the electric motor.

[0013] According to the power transmission device of this disclosure, the electric motor may also have a housing that houses the rotor and stator. Furthermore, the control unit may also be housed within the housing.

[0014] According to the power transmission device of this disclosure, the flow adjustment unit may also be composed of a solenoid valve.

[0015] The power transmission device according to the present disclosure may also include a pump control unit configured to control the aforementioned oil pump. Furthermore, the pump control unit may be configured to control the rotational speed of the oil pump based on the opening degree of the flow adjustment unit.

[0016] According to the power transmission device with the above structure, for example, when the opening of the flow adjustment section is relatively small, i.e., when the oil supply required by the motor is relatively small, the rotational speed (workload) of the oil pump can be reduced.

[0017] As described above, the power transmission device according to this disclosure can provide a power transmission device that reduces the workload of the oil pump.

[0018] The features, advantages, and technical and industrial importance of embodiments of the present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals denote the same elements. Attached Figure Description

[0019] Figure 1 This is a perspective view schematically illustrating a power transmission device in one embodiment of the present disclosure.

[0020] Figure 2 It is a general representation Figure 1 The circuit diagram of the power transmission device is shown.

[0021] Figure 3 It is a general representation Figure 1 The diagram shows the electric motor.

[0022] Figure 4 It means Figure 2 The flowchart shows an example of the control content of the control unit. Detailed Implementation

[0023] Embodiments of this disclosure will be described with reference to the accompanying drawings. Furthermore, in the drawings referred to below, the same or equivalent parts are labeled with the same reference numerals.

[0024] Figure 1 This is a diagram that schematically illustrates a power transmission device in one embodiment of the present disclosure. Figure 2 It is a circuit diagram that roughly represents a power transmission device.

[0025] In this embodiment, the power transmission device 1 is mounted on a vehicle. Examples of vehicles include hybrid electric vehicles, plug-in hybrid electric vehicles, and battery electric vehicles.

[0026] like Figure 1 and Figure 2 As shown, the power transmission device 1 includes a housing 10, a single oil pump 100, an electric motor 200, a lubricated component 300, an oil passage L, a flow adjustment unit 400, and a control device 500.

[0027] The housing 10 houses a single oil pump 100, an electric motor 200, a lubricated component 300, an oil passage L, a flow adjustment unit 400, and a control device 500. The lower part of the housing 10 forms an oil storage section 12.

[0028] Oil pump 100 can deliver oil. Oil pump 100 draws oil from oil reservoir 12 via filter 110.

[0029] The electric motor 200 is, for example, composed of a motor. Figure 3 This is an example of an electric motor 200. For example... Figure 3 As shown, the electric motor 200 has a stator 210, a rotor 220, a drive shaft 230, a housing 240, and a gear section 250.

[0030] A rotor 220 is disposed inside the stator 210, and a drive shaft 230 is disposed inside the rotor 220. A housing 240 houses the stator 210, the rotor 220, and the drive shaft 230.

[0031] The gear section 250 is connected to the drive shaft 230. The gear section 250 is disposed within the housing 240. The gear section 250 includes a sun gear 251, a stepped pinion 252, a ring gear 253, a planet carrier 254, and a differential gear 255.

[0032] The sun gear 251 is connected to the drive shaft 230. The stepped pinion 252 has two gear sections. One of the two gear sections meshes with the sun gear 251, and the other meshes with the ring gear 253. The ring gear 253 is fixed to the housing 240. The stepped pinion 252 is supported by the planet carrier 254. Input from the sun gear 251 is input to the stepped pinion 252 supported by the planet carrier 254. The stepped pinion 252, under the reaction force of the ring gear 253, transmits power to the planet carrier 254. The planet carrier 254 transmits power to the differential gear 255, thereby transmitting power to the drive shaft 230 via the differential shaft.

[0033] The lubricated component 300 is a component that is lubricated by oil. Examples of lubricated components 300 include gears and shafts. The lubricated component 300 may also include cooled components such as terminal blocks.

[0034] Oil passage L is a flow path for supplying oil from oil pump 100 to motor 200 and lubricated components 300. Oil passage L is formed within housing 10. Figure 2 As shown, the oil circuit L includes the first oil circuit L1 and the second oil circuit L2.

[0035] The first oil passage L1 is a flow path for supplying oil from the oil pump 100 to the electric motor 200. The first oil passage L1 connects the oil pump 100 and the electric motor 200. In addition, the oil supplied to the electric motor 200 flows into the oil storage section 12.

[0036] In this embodiment, an oil cooler 120 is provided in the first oil passage L1. The oil cooler 120 is, for example, a heat exchanger. The oil cooler 120 cools the oil flowing in the first oil passage L1 using a cooling medium. Alternatively, the oil cooler 120 may be provided outside the housing 10.

[0037] The second oil passage L2 is a flow path used to supply oil from the oil pump 100 to the lubricated component 300. The second oil passage L2 branches off from the first oil passage L1. Figure 2 As shown, the second oil passage L2 branches off from the downstream side of the oil cooler 120 in the first oil passage L1. Furthermore, oil supplied to the lubricated component 300 flows into the oil reservoir 12.

[0038] The flow rate regulating unit 400 is capable of adjusting the amount of oil supplied to the electric motor 200. The flow rate regulating unit 400 is composed of a solenoid valve. The flow rate regulating unit 400 is provided in the oil passage L. In this embodiment, the flow rate regulating unit 400 is provided at the connection point P between the first oil passage L1 and the second oil passage L2 and the electric motor 200. Alternatively, the flow rate regulating unit 400 may be provided in the second oil passage L2. Furthermore, the flow rate regulating unit 400 may also be composed of a three-way valve provided at the connection point P.

[0039] The control device 500 controls various equipment. For example... Figure 1 As shown, the control device 500 can also be disposed within the housing 10. The control device 500 includes a control unit 501, a vehicle-side ECU 502, and a pump control unit 503.

[0040] The control unit 501 controls the flow adjustment unit 400. Specifically, the control unit 501 controls the opening degree of the flow adjustment unit 400. The control unit 501 is composed of an ECU (Electronic Control Unit). For example, the control unit 501 may also control the opening degree of the flow adjustment unit 400 based on the temperature T of the motor 200. The temperature T of the motor 200 is detected, for example, by a temperature sensor 801 provided on the stator 210.

[0041] Figure 4 This is an example of the control flow of control unit 501. For example... Figure 4 As shown, if the motor 200 is driven (step S1), the control unit 501 determines whether the temperature T of the motor 200 is above the high reference temperature TH (step S2). As a result, if the temperature T of the motor 200 is above the high reference temperature TH, the control unit 501 increases the opening of the flow rate adjustment unit 400, that is, increases the cooling amount of the motor 200 (step S3).

[0042] After step S3, or if the result of step S2 is negative, control unit 501 determines whether the temperature T of motor 200 is lower than the low reference temperature TL, which is lower than the high reference temperature TH (step S4). As a result, if the temperature T of motor 200 is lower than the low reference temperature TL, control unit 501 reduces the opening of flow adjustment unit 400, i.e., reduces the cooling amount of motor 200 (step S5), and returns to step S2. On the other hand, if the temperature T of motor 200 is higher than the low reference temperature TL in step S4, control unit 501 returns to step S2.

[0043] In addition, the high reference temperature TH and the low reference temperature TL are preset.

[0044] The control unit 501 can also control the opening degree of the flow adjustment unit 400 based on the temperature of the oil flowing into the motor 200. The temperature of the oil flowing into the motor 200 is detected downstream of the oil cooler 120. Figure 2 In the example shown, the temperature of the oil flowing into the motor 200 is detected by a temperature sensor 802 located in the second oil circuit L2. However, the temperature sensor 802 may also be located downstream of the oil cooler 120 in the first oil circuit L1. Even in this case, the flowchart of the control unit 501 remains the same as described above.

[0045] Alternatively, the control unit 501 may control the opening of the flow adjustment unit 400 based on the pressure surrounding the motor 200. The pressure surrounding the motor 200 may refer, for example, to the pressure inside the housing 240. The pressure inside the housing 240 is detected by a pressure sensor 803 installed inside the housing 240.

[0046] Here, the temperature of the motor 200, the temperature of the oil flowing into the motor 200, and the pressure around the motor 200 can be calculated, for example, based on the current value of the motor 200, the rotational speed, the rotational speed of the oil pump 100, and the cooling capacity of the oil cooler 120.

[0047] The vehicle-side ECU 502 controls various devices in the vehicle. The control unit 501 can also control the flow adjustment unit 400 based on signals from the vehicle-side ECU 502.

[0048] The pump control unit 503 controls the oil pump 100. The pump control unit 503 can adjust the workload (rotation speed) of the oil pump 100 according to the opening degree of the flow adjustment unit 400. The opening degree of the flow adjustment unit 400 can be detected by sensing the flow adjustment unit 400 itself, or it can be detected based on the signal sent to the flow adjustment unit 400 by the control unit 501.

[0049] As explained above, in the power transmission device 1 of this embodiment, since the control unit 501 can adjust the amount of oil supplied to the motor 200, for example, by increasing the amount of oil supplied to the motor 200, the motor 200 can be effectively cooled, thus reducing the frequency of cooling requirements for the motor 200. Therefore, the workload of the oil pump 100 can be reduced.

[0050] Furthermore, the embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of this disclosure is not shown by the description of the embodiments above but by the technical solutions, and further includes all modifications within the meaning and scope of equivalent technical solutions.

Claims

1. A power transmission device, characterized in that, Include: A single oil pump is configured to deliver oil. Electric motor; The lubricated component is lubricated by the oil; The oil circuit is configured to supply the oil pumped from the oil pump to the electric motor and the lubricated components; A flow rate adjustment unit is configured to be installed in the oil circuit and to adjust the oil supply to the electric motor; and The control unit is configured to control the flow adjustment unit.

2. The power transmission device according to claim 1, characterized in that, The oil circuit has: The first oil circuit is configured to supply oil from the oil pump to the electric motor; and The second oil passage is configured to branch off from the first oil passage and supply the oil pumped from the oil pump to the lubricated component. The flow adjustment unit is located between the connection between the first oil circuit and the second oil circuit and the motor.

3. The power transmission device according to claim 1, characterized in that, The control unit is configured to control the opening degree of the flow adjustment unit based on the temperature of the motor.

4. The power transmission device according to claim 3, characterized in that, When the temperature of the motor is above the high reference temperature, the control unit increases the opening of the flow adjustment unit.

5. The power transmission device according to claim 1, characterized in that, The control unit is configured to control the opening degree of the flow rate adjustment unit based on the temperature of the oil flowing into the electric motor.

6. The power transmission device according to claim 1, characterized in that, The control unit is configured to control the opening degree of the flow adjustment unit based on the pressure around the motor.

7. The power transmission device according to claim 1, characterized in that, The electric motor has a housing that accommodates the rotor and stator. The control unit is located inside the housing.

8. The power transmission device according to claim 1, characterized in that, The flow adjustment unit is composed of a solenoid valve.

9. The power transmission device according to claim 7, characterized in that, It further includes a pump control unit configured to control the oil pump. in, The pump control unit is configured to control the rotational speed of the oil pump based on the opening degree of the flow adjustment unit.

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