Motor cooling and lubrication system for hybrid transmission

Abstract

A motor cooling and lubrication system for a hybrid transmission comprises an oil tank, a filter, and an oil cooler. The oil tank is connected to an oil inlet of the filter through a main oil circuit. The oil inlet of a first mechanical pump is connected to a first oil outlet of the filter through a first oil circuit. The oil outlet of the first mechanical pump is connected to the oil cooler. The first mechanical pump is driven by a gear circumferentially fixed on an input shaft of the transmission. The oil inlet of a second mechanical pump is connected to a second oil outlet of the filter through a second oil circuit. The oil outlet of the second mechanical pump is connected to the oil cooler. A first bypass is provided between the oil outlet of the second mechanical pump and the second oil circuit. A second bypass is provided between the oil inlet of the second mechanical pump and a downstream end of a second one-way valve. A driven gear of the second mechanical pump meshes with a main reduction gear of a differential. The oil outlet of the oil cooler provides cooling and lubricating oil to a bearing subsystem, a motor stator, and an electronic rotor through a cooling and lubricating oil circuit. The bearing subsystem and the motor stator are respectively connected to the oil tank through an oil return circuit.

Description

Technical Field

[0001] The invention relates to the technical field of cooling and lubrication, and in particular to a motor cooling and lubrication system of a hybrid power transmission. Background Art

[0002] At present, the existing hybrid transmission cooling and lubrication system usually consists of an electronic pump and a mechanical pump to suck oil. The electronic pump is driven by the oil pump motor, and the mechanical pump is connected to the gear set at the output end. When the whole vehicle is in reverse condition, the gear set at the output end will reverse, causing the mechanical pump to reverse under the drive of the reversed gear set. Since the oil circuit where the mechanical pump is located cannot make the lubricating oil flow in the opposite direction, the mechanical pump will idle under the reverse condition, causing the lubricating oil circuit to be oil-free, affecting the lubrication effect. Summary of the invention

[0003] The purpose of the present invention is to address the deficiencies in the prior art and provide a motor cooling and lubrication system for a hybrid transmission, which has a simple structure and a small size, can prevent the mechanical pump from idling under reverse gear conditions, and can provide lubricating oil for the cooling and lubricating oil circuit under any operating conditions.

[0004] The technical solution of the present invention is: a motor cooling and lubrication system of a hybrid transmission, comprising an oil tank, a filter, and an oil cooler, wherein the oil tank is connected to an oil inlet of the filter through a main oil circuit, and further comprises a first mechanical pump and a second mechanical pump, wherein an oil inlet of the first mechanical pump is connected to a first oil outlet of the filter through a first oil circuit, and an oil outlet of the first mechanical pump is connected to an oil cooler through a first one-way valve, wherein the first mechanical pump is driven by a gear circumferentially fixed on a transmission input shaft, and an oil inlet of the second mechanical pump is connected to a second oil outlet of the filter through a second oil circuit, and an oil outlet of the second mechanical pump is connected to an oil cooler through a second one-way valve. The second mechanical pump is connected to the oil cooler, a first bypass is arranged between the oil outlet of the second mechanical pump and the second oil circuit, a third one-way valve is arranged on the first bypass, a second bypass is arranged between the oil inlet of the second mechanical pump and the downstream end of the second one-way valve, a fourth one-way valve is arranged on the second bypass, a driven gear is circumferentially fixed on the driving shaft of the second mechanical pump, and the driven gear is used to mesh with the main reduction gear of the differential, the oil outlet of the oil cooler provides cooling lubricating oil to the bearing subsystem, the motor stator and the electronic rotor through the cooling lubricating oil circuit, and the bearing subsystem and the motor stator are respectively connected to the oil tank through the return oil circuit.

[0005] Furthermore, a fifth one-way valve is provided on the second oil circuit.

[0006] Furthermore, a driving gear is circumferentially fixed on the driving shaft of the first mechanical pump, and the driving gear is meshed with a gear circumferentially fixed on the transmission input shaft.

[0007] Furthermore, the cooling lubricating oil circuit provides lubricating oil to the bearing subsystem via a first lubricating branch, and a first throttling hole is arranged on the first lubricating branch.

[0008] Furthermore, the cooling lubricating oil circuit provides cooling lubricating oil to the motor rotor via a second lubricating branch, and a second throttling hole is arranged on the second lubricating branch.

[0009] Furthermore, the cooling lubricating oil circuit provides cooling lubricating oil to the motor stator via a third lubricating branch, and a third throttling hole is arranged on the third lubricating branch.

[0010] Furthermore, a fourth lubrication branch is provided between the bearing subsystem and the motor rotor, and a fourth throttle hole is provided on the fourth lubrication branch.

[0011] Furthermore, a fifth lubrication branch is provided between the motor rotor and the motor stator.

[0012] Adopting the above technical solution: This cooling and lubrication system uses two mechanical pumps to realize cooling and lubrication of the motor system and the bearing subsystem, wherein the first mechanical pump meshes with the gear circumferentially fixed on the input shaft through the driving gear, and the first mechanical pump can work with the operation of the engine, and the second mechanical pump meshes with the main reduction gear of the differential through the driven gear, and the second mechanical pump can work forward when the whole vehicle is moving forward, and can work reversely when the whole vehicle is in reverse gear, so that this system can provide cooling lubricating oil for the motor and the transmission under any working conditions, solving the problem of no oil in the lubricating oil circuit of the existing lubrication system when the whole vehicle is in reverse gear. Moreover, the control strategy of this system is simple, and it only needs to control the distribution of oil through the throttle hole, and does not need to use a hydraulic module for flow distribution, which can reduce production costs.

[0013] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the system principle diagram of the present invention;

[0015] Figure 2 It is the principle diagram of mode 1 of the present invention;

[0016] Figure 3 This is a schematic diagram of the second mode of the present invention;

[0017] Figure 4 This is a schematic diagram of the third mode of the present invention;

[0018] Figure 5 This is a schematic diagram of mode 4 of the present invention. DETAILED DESCRIPTION

[0019] See also Figures 1 to 5A motor cooling and lubrication system for a hybrid transmission includes an oil tank 1, a filter 2, and an oil cooler 6. The oil tank 1 is connected to the oil inlet of the filter 2 through the main oil circuit L1. The filter 2 filters out impurities and particles in the lubricating oil, thereby protecting the motor and the transmission. It also includes a first mechanical pump 3 and a second mechanical pump 7. The oil inlet of the first mechanical pump 3 is connected to the first oil outlet of the filter 2 through the first oil circuit L2. The oil outlet of the first mechanical pump 3 is connected to the oil cooler 6 through the first check valve 5. The first check valve 5 prevents the lubricating oil in the oil cooler 6 from flowing back to the filter 2. The first mechanical pump 3 is driven by a gear circumferentially fixed on the input shaft of the transmission. A driving gear is circumferentially fixed on the driving shaft of the first mechanical pump 3. The driving gear is meshed with a gear circumferentially fixed on the input shaft of the transmission. When the engine is running, the gear circumferentially fixed on the input shaft rotates, thereby driving the first mechanical pump 3 to work. The flow rate of lubricating oil in the first oil circuit L2 is controlled by the engine. The higher the engine speed, the higher the speed of the first mechanical pump 3, and the greater the flow rate of lubricating oil in the first oil circuit L2. The oil inlet of the second mechanical pump 7 is connected to the second oil outlet of the filter 2 via the second oil circuit L3, and the oil outlet of the second mechanical pump 7 is connected to the oil cooler 6 via the second one-way valve 10, and the lubricating oil in the oil cooler 6 is prevented from flowing back through the second one-way valve 10. The second oil circuit L3 is provided with a fifth one-way valve 18, and the lubricating oil in the second oil circuit L3 is prevented from flowing back to the filter 2 through the fifth one-way valve 18. A first bypass L32 is provided between the oil outlet of the second mechanical pump 7 and the second oil circuit L3, and a third one-way valve 19 is provided on the first bypass L32. A second bypass L31 is provided between the oil inlet of the second mechanical pump 7 and the downstream end of the second one-way valve 10, and a fourth one-way valve 9 is provided on the second bypass L31, and the lubricating oil in the first bypass L32 is prevented from flowing back to the filter 2 through the third one-way valve 19. A driven gear is fixed circumferentially on the driving shaft of the second mechanical pump 7, and the driven gear is used to mesh with the main reduction gear of the differential. When the vehicle moves forward or reverses, the transmission shaft will drive the main reduction gear to rotate forward or reverse, thereby driving the second mechanical pump 7 to work, so that the second mechanical pump 7 can work to pump oil no matter what working condition the vehicle is in. The flow rate of the second oil circuit L3 is controlled by the vehicle speed. The higher the vehicle speed, the greater the flow rate of the second oil circuit L3.

[0020] The oil outlet of the oil cooler 6 provides cooling lubricating oil to the bearing subsystem 15, the motor stator 17 and the electronic rotor 14 through the cooling lubricating oil circuit L4. The bearing subsystem 15 and the motor stator 17 are respectively connected to the oil tank 1 through the return oil circuit L5. The cooling lubricating oil circuit L4 provides lubricating oil to the bearing subsystem 15 through the first lubricating branch L43, and the first throttle hole 13 is provided on the first lubricating branch L43. The cooling lubricating oil circuit L4 provides cooling lubricating oil to the motor rotor 14 through the second lubricating branch L42, and the second throttle hole 12 is provided on the second lubricating branch L42. The cooling lubricating oil circuit L4 provides cooling lubricating oil to the motor stator 17 through the third lubricating branch L41, and the third throttle hole 11 is provided on the third lubricating branch L41. The flow rate of the lubricating oil is reduced through the first throttle hole 13, the second throttle hole 12, and the third throttle hole 11. A fourth lubrication branch L422 is arranged between the bearing subsystem 15 and the motor rotor 14, and a fourth throttle hole 16 is arranged on the fourth lubrication branch L422. A fifth lubrication branch L421 is arranged between the motor rotor 14 and the motor stator 17. No throttle hole is arranged on the fifth lubrication branch L421, so that most of the cooling oil can be provided to the motor stator 17. A fourth throttle hole 16 is arranged on the fourth lubrication branch L422, so that less lubrication oil is provided to the bearing subsystem 15, thereby giving full play to the cooling and lubrication effect of the system.

[0021] In practical applications, this cooling and lubrication system has multiple working modes:

[0022] Mode 1, such as Figure 2 As shown, under the parking power generation condition, the whole vehicle is in a parking state, and the engine is running to drive the generator for charging. At this time, the engine drives the first mechanical pump 3 to work through the input shaft, and the second mechanical pump 7 stops. The lubricating oil in the oil tank 1 enters the first oil circuit L2 through the main oil circuit L1 and the filter 2, and then enters the oil cooler 6 through the first mechanical pump 3 and the first non-return valve 5. After the lubricating oil is cooled in the oil cooler 6, it is distributed to the bearing subsystem 15 through the cooling lubricating oil circuit L4 and the first lubricating branch L43 for lubrication, and is distributed to the motor rotor 14 and the motor stator 17 through the second lubricating branch L42 and the third lubricating branch L41 respectively to cool the motor. The lubricating oil entering the motor rotor 14 is provided to the bearing subsystem 15 and the motor stator 17 through the fourth lubricating branch L422 and the fifth lubricating branch L421 respectively. Finally, the lubricating oil in the bearing subsystem 15 and the motor stator 17 is collected in the return oil circuit L5 and returned to the oil tank 1.

[0023] Mode 2, such as Figure 3As shown, the second mechanical pump 7 works alone. At this time, the vehicle is moving at a high speed. At this time, the amount of lubricating oil provided by the second mechanical pump 7 can meet the consumption of the entire system. The main reduction gear drives the second mechanical pump 7 to operate, and the lubricating oil enters the second oil circuit L3 through the main oil circuit L1 and the filter 2, and is then transported to the oil cooler 6 for cooling through the second one-way valve 10. Under the action of the first one-way valve 5, the lubricating oil in the oil cooler 6 will not flow back to the first oil circuit L2. The cooled lubricating oil is distributed to the bearing subsystem 15, the motor rotor 14 and the motor stator 17 through the cooling lubricating oil circuit L4. The lubricating oil entering the motor rotor 14 is respectively provided to the bearing subsystem 15 and the motor stator 17 through the fourth lubricating branch L422 and the fifth lubricating branch L421. Finally, the lubricating oil in the bearing subsystem 15 and the motor stator 17 is collected in the return oil circuit L5 and returned to the oil tank 1.

[0024] Mode three, such as Figure 4 As shown, the first mechanical pump 3 and the second mechanical pump 7 work simultaneously, which is the main working mode of the system. The lubricating oil enters the oil cooler 6 through the main oil circuit L1 and the filter 2 respectively through the first oil circuit L2 and the second oil circuit L3 for cooling. The cooled lubricating oil is distributed to the bearing subsystem 15, the motor rotor 14 and the motor stator 17 through the cooling lubricating oil circuit L4. The lubricating oil entering the motor rotor 14 is respectively provided to the bearing subsystem 15 and the motor stator 17 through the fourth lubricating branch L422 and the fifth lubricating branch L421. Finally, the lubricating oil in the bearing subsystem 15 and the motor stator 17 is collected in the return oil circuit L5 and returned to the oil tank 1. The flow rate of the lubricating oil in the first oil circuit L2 is controlled by the engine. The higher the engine speed, the greater the flow rate. The flow rate of the lubricating oil in the second oil circuit L3 is controlled by the vehicle speed. The higher the vehicle speed, the greater the flow rate. When the flow rate of the second oil circuit L3 is insufficient, the engine speed can be increased to increase the speed of the first mechanical pump 3 to increase the flow rate, which is used to supplement the flow rate of the second oil circuit L3.

[0025] Mode 4, such as Figure 5 As shown, the whole vehicle is in the reversing condition, and the second mechanical pump 7 is driven to reverse through the main reduction gear, and the lubricating oil enters the filter 2 through the main oil circuit L1, and the filtered lubricating oil enters the oil cooler 6 through the first bypass L32 and the second bypass L31 for cooling, and the cooled lubricating oil is distributed to the bearing subsystem 15, the motor rotor 14 and the motor stator 17 through the cooling lubricating oil circuit L4, and the lubricating oil entering the motor rotor 14 is respectively provided to the bearing subsystem 15 and the motor stator 17 through the fourth lubricating branch L422 and the fifth lubricating branch L421, and finally the lubricating oil in the bearing subsystem 15 and the motor stator 17 is collected in the return oil circuit L5 and returned to the oil tank 1. This mode can ensure that the second mechanical pump 7 will not idle when the whole vehicle is reversing, thereby ensuring that the lubricating oil can lubricate the entire system under the reversing condition.

[0026] The control strategy of the cooling and lubrication system is simple. It only needs to control the distribution of oil through the throttle hole, and does not need to use a hydraulic module for flow distribution, which can reduce production costs. Two mechanical pumps are used to realize the cooling and lubrication of the motor system and the bearing subsystem 15, wherein the first mechanical pump 3 is meshed with the gear circumferentially fixed on the input shaft through the driving gear, so the first mechanical pump 3 can work with the operation of the engine, and the second mechanical pump 7 is meshed with the main reduction gear of the differential through the driven gear, so the second mechanical pump 7 can work in forward rotation when the whole vehicle is moving forward, and can work in reverse when the whole vehicle is in reverse gear, so that the system can provide cooling lubricating oil for the motor and the inside of the transmission under any working conditions, solving the problem of no oil in the lubricating oil circuit of the existing lubrication system when the whole vehicle is in reverse gear.

Claims

1. A motor cooling and lubrication system for a hybrid transmission, comprising an oil tank (1), a filter (2), and an oil cooler (6), wherein the oil tank (1) is connected to an oil inlet of the filter (2) via a main oil circuit (L1), and is characterized in that: The transmission also comprises a first mechanical pump (3) and a second mechanical pump (7), wherein the oil inlet of the first mechanical pump (3) is connected to the first oil outlet of the filter (2) via a first oil circuit (L2), and the oil outlet of the first mechanical pump (3) is connected to the oil cooler (6) via a first non-return valve (5); the first mechanical pump (3) is driven by a gear circumferentially fixed on the input shaft of the transmission, the oil inlet of the second mechanical pump (7) is connected to the second oil outlet of the filter (2) via a second oil circuit (L3), a fifth non-return valve (18) is provided on the second oil circuit (L3), the oil outlet of the second mechanical pump (7) is connected to the oil cooler (6) via a second non-return valve (10), and a valve (18) is provided between the oil outlet of the second mechanical pump (7) and the second oil circuit (L3). A first bypass (L32) is provided, a third one-way valve (19) is provided on the first bypass (L32), a second bypass (L31) is provided between the oil inlet of the second mechanical pump (7) and the downstream end of the second one-way valve (10), a fourth one-way valve (9) is provided on the second bypass (L31), a driven gear is circumferentially fixed on the drive shaft of the second mechanical pump (7), the driven gear is used to mesh with the main reduction gear of the differential, the oil outlet of the oil cooler (6) provides cooling lubricating oil to the bearing subsystem (15), the motor stator (17) and the electronic rotor through the cooling lubricating oil circuit (L4), and the bearing subsystem (15) and the motor stator (17) are respectively connected to the oil tank (1) through the oil return circuit (L5).

2. The motor cooling and lubrication system of the hybrid transmission according to claim 1, characterized in that: A driving gear is circumferentially fixed on the driving shaft of the first mechanical pump (3), and the driving gear is meshed with a gear circumferentially fixed on the transmission input shaft.

3. The motor cooling and lubrication system of the hybrid transmission according to claim 1, characterized in that: The cooling lubricating oil circuit (L4) provides lubricating oil to the bearing subsystem (15) via a first lubricating branch circuit (L43), and a first throttling hole (13) is provided on the first lubricating branch circuit (L43).

4. The motor cooling and lubrication system of the hybrid transmission according to claim 1, characterized in that: The cooling lubricating oil circuit (L4) provides cooling lubricating oil to the motor rotor (14) via a second lubricating branch circuit (L42), and a second throttling hole (12) is provided on the second lubricating branch circuit (L42).

5. The motor cooling and lubrication system of the hybrid transmission according to claim 1, characterized in that: The cooling lubricating oil circuit (L4) provides cooling lubricating oil to the motor stator (17) via a third lubricating branch circuit (L41), and a third throttle hole (11) is provided on the third lubricating branch circuit (L41).

6. The motor cooling and lubrication system of the hybrid transmission according to claim 1, characterized in that: A fourth lubrication branch (L422) is provided between the bearing subsystem (15) and the motor rotor (14), and a fourth throttling hole (16) is provided on the fourth lubrication branch (L422).

7. The motor cooling and lubrication system of the hybrid transmission according to claim 1, characterized in that: A fifth lubrication branch (L421) is provided between the motor rotor (14) and the motor stator (17).

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