Hydraulic system, powertrain and vehicle

Abstract

The utility model provides a kind of hydraulic system of transmission, power system and vehicle, the hydraulic system of transmission includes: valve body assembly and external electronic pump;Valve body assembly has mechanical pump, main oil circuit and cooling oil circuit;Mechanical pump is connected with the control oil circuit of clutch by main oil circuit, to control the engagement or separation of clutch;External electronic pump is communicated with main oil circuit by cooling oil circuit, to supplement oil supply to valve body assembly when mechanical pump oil supply is insufficient.Such, only integrated one mechanical pump in valve body assembly, simple structure, less space requirement arrangement;And, by external electronic pump, reduce the demand of valve body assembly to arrangement space, so that the arrangement of valve body assembly is more flexible, and can reduce cost;At the same time, external electronic pump can realize accurate control to flow, can supplement the oil quantity lacking in time when mechanical pump oil supply is insufficient, reduce the energy consumption of complete machine, to further reduce cost.

Description

Technical Field

[0001] This utility model relates to the field of vehicle technology, specifically to a hydraulic system for a transmission, a power system, and a vehicle. Background Technology

[0002] In a transmission, a hydraulic system is used to control the pressure of the clutch, enabling the clutch to disengage and engage, and thus allowing switching between different power modes. Simultaneously, the transmission also requires a hydraulic system to provide cooling oil to cool and lubricate components such as the clutch, drive motor, generator, and gears, and to adjust the oil flow in each circuit as needed.

[0003] In existing technologies, whether the pump body is driven by an electric motor or by gear meshing, a large layout space is required, and various auxiliary components are needed to control, cool, and lubricate the clutch, resulting in high costs and significant software control difficulties. Utility Model Content

[0004] In view of this, the present invention aims to provide a hydraulic system, a power system, and a vehicle for a transmission, in order to solve the problems of large layout space, complex structure, high cost, and difficulty in control of the power system in the prior art.

[0005] To solve the above-mentioned technical problems, this utility model provides a hydraulic system for a transmission, comprising: The valve body assembly includes a mechanical pump, a main oil passage, and a cooling oil passage; the mechanical pump is connected to the clutch control oil passage through the main oil passage to control the engagement or disengagement of the clutch; An external electronic pump is connected to the main oil circuit through the cooling oil circuit to supplement the oil supply to the valve body assembly when the mechanical pump's oil supply is insufficient.

[0006] In one embodiment, the valve body assembly includes a solenoid valve disposed on the main oil line and located between the mechanical pump and the clutch, the solenoid valve being used to connect or disconnect the connection between the mechanical pump and the clutch.

[0007] In one embodiment, the valve body assembly includes a pressure regulating valve and a first drive oil circuit; the pressure regulating valve has a first control terminal; One end of the first drive oil circuit is connected to the main oil circuit, and the other end is connected to the first control terminal; The mechanical pump supplies oil to the first control terminal through the first drive oil circuit and drives the valve core of the pressure regulating valve to move, so as to open the oil inlet and oil outlet of the pressure regulating valve. The oil inlet of the pressure regulating valve is connected to the main oil circuit, and the oil outlet of the pressure regulating valve is connected to the cooling oil circuit. The oil in the main oil circuit flows into the cooling oil circuit through the pressure regulating valve to reduce the pressure in the main oil circuit.

[0008] In one embodiment, the valve body assembly includes a second drive oil passage; The pressure regulating valve has a second control terminal, one end of the second drive oil circuit is connected to the main oil circuit, and the other end is connected to the second control terminal; When the electromagnetic switch valve is opened, a portion of the oil is supplied to the second control terminal via the second drive oil circuit, and the valve core of the pressure regulating valve is driven to move in the opposite direction to close the oil inlet of the pressure regulating valve.

[0009] In one embodiment, the hydraulic system includes a first cooling oil passage and a second cooling oil passage, the first cooling oil passage and the second cooling oil passage respectively supplying cooling oil to components in the power system; the valve body assembly includes an oil cooler; The oil cooler is installed on the cooling oil circuit. One end of the cooling oil circuit is connected to the pressure regulating valve and the external electronic pump, and the other end is connected to the first cooling oil passage and the second cooling oil passage.

[0010] In one embodiment, the valve body assembly includes a directional valve and a third drive oil circuit; the directional valve has a control end; One end of the third drive oil circuit is connected to the main oil circuit, and the other end is connected to the control terminal; The mechanical pump supplies oil to the control terminal through the third drive oil circuit and drives the valve core of the reversing valve to move, so as to open the oil inlet and oil outlet of the reversing valve. The cooling oil circuit includes a first output section and a second output section, wherein the first output section is connected to the first cooling oil passage and the second output section is connected to the second cooling oil passage; The oil inlet of the reversing valve is connected to the second output section, and the oil outlet of the reversing valve is connected to the first output section, which is used to adjust the flow distribution between the first cooling oil passage and the second cooling oil passage.

[0011] In one embodiment, the hydraulic system includes a suction filter, one end of the main oil circuit is connected to the suction filter, and the other end is connected to the mechanical pump and / or the external electronic pump, respectively, for providing filtered oil to the mechanical pump and / or the external electronic pump respectively; In the first mode, the main oil circuit is connected to the external electric pump, and the external electric pump is connected to the first cooling oil passage and the second cooling oil passage respectively through the cooling oil circuit; wherein the first mode is the vehicle's power system in pure electric mode.

[0012] In one embodiment, the hydraulic system includes a suction filter, one end of the main oil circuit is connected to the suction filter, and the other end is connected to the mechanical pump and / or the external electronic pump, respectively, for providing filtered oil to the mechanical pump and / or the external electronic pump respectively; In the second mode, the mechanical pump is driven by the vehicle engine, the main oil circuit is connected to the mechanical pump and the external electronic pump respectively, the electromagnetic switch valve is closed, and the mechanical pump drives the valve core of the pressure regulating valve through the first drive oil circuit, and opens the oil inlet and outlet of the pressure regulating valve; wherein the second mode is the vehicle's power system in series mode; The oil flowing through the main oil circuit flows into the cooling oil circuit via the pressure regulating valve, where it mixes with the oil supplied by the external electronic pump and flows together into the first and second cooling oil passages. The mechanical pump drives the valve core of the reversing valve through the third drive oil circuit and opens the inlet and outlet of the reversing valve to distribute the oil volume of the first and second cooling oil passages.

[0013] In one embodiment, the hydraulic system includes a suction filter, one end of the main oil circuit is connected to the suction filter, and the other end is connected to the mechanical pump and / or the external electronic pump, respectively, for providing filtered oil to the mechanical pump and / or the external electronic pump respectively; In the third mode, the mechanical pump is driven by the vehicle engine, the main oil circuit is connected to the mechanical pump and the external electronic pump respectively, the electromagnetic switch valve is opened, the mechanical pump drives the clutch to engage, and drives the valve core of the pressure regulating valve through the second drive oil circuit to close the oil inlet of the pressure regulating valve; wherein the third mode is the vehicle's power system in parallel mode; The oil supplied by the external electronic pump flows through the cooling oil circuit to the first cooling oil passage and the second cooling oil passage; the mechanical pump drives the valve core of the reversing valve through the third drive oil circuit and opens the oil inlet and outlet of the reversing valve to distribute the oil volume of the first cooling oil passage and the second cooling oil passage. When the vehicle's power system exits the third mode, the electromagnetic switch valve is turned off, and the clutch is disengaged.

[0014] In one embodiment, the valve assembly includes a first check valve and a second check valve. The first check valve is disposed between the oil outlet of the pressure regulating valve and the cooling oil circuit, allowing unidirectional flow of oil through the oil outlet of the pressure regulating valve to the cooling oil circuit. The second check valve is disposed between the external electric pump and the cooling oil circuit, allowing unidirectional flow of oil through the external electric pump to the cooling oil circuit; and / or, The valve body assembly includes a first safety valve and a second safety valve. The first safety valve is connected to the main oil circuit and opens when the pressure in the main oil circuit exceeds a predetermined pressure, thereby discharging oil from the main oil circuit into the valve body assembly. The second safety valve is connected to the cooling oil circuit and opens when the pressure in the cooling oil circuit exceeds a predetermined pressure, thereby discharging oil from the cooling oil circuit into the valve body assembly. And / or, The valve assembly includes a filter press and a bypass valve. The main oil circuit has an oil supply branch. The filter press is located on the main oil circuit, and the bypass valve is located on the oil supply branch. The oil supply branch is connected in parallel with the main oil circuit. When the oil pressure in the main oil circuit is greater than a predetermined pressure, the bypass valve opens the oil supply branch.

[0015] To solve the above-mentioned technical problems, this utility model embodiment also provides a power system, including an engine and a hydraulic system of the transmission as described above; The engine has an input shaft connected to the mechanical pump, and the engine drives the mechanical pump to operate through the input shaft.

[0016] To address the aforementioned technical problems, this utility model also provides a vehicle, including the power system described above.

[0017] Compared with existing valve body assemblies, the hydraulic system of the transmission provided in this embodiment of the invention has the following advantages: This utility model provides a hydraulic system for a transmission, including a valve body assembly and an external electronic pump. The valve body assembly has a mechanical pump, a main oil circuit, and a cooling oil circuit. The mechanical pump is connected to the clutch control oil circuit through the main oil circuit to control the engagement or disengagement of the clutch. The external electronic pump is connected to the main oil circuit through the cooling oil circuit to supplement the valve body assembly with oil when the mechanical pump's oil supply is insufficient. Thus, only one mechanical pump is integrated into the valve body assembly, resulting in a simple structure and smaller space requirements. Furthermore, by externalizing the electronic pump, the space required for the valve body assembly is reduced, thereby reducing costs. Simultaneously, the external electronic pump can precisely control the flow rate, supplementing insufficient oil and reducing overall energy consumption, further reducing costs. Attached Figure Description

[0018] Figure 1 A schematic diagram of a hydraulic system provided for an embodiment of this utility model.

[0019] Figure 2 This is a schematic diagram of a hydraulic system provided in an embodiment of the present invention.

[0020] Figure 3This is another structural schematic diagram of the hydraulic system provided in an embodiment of the present utility model.

[0021] The explanations of the reference numerals in the accompanying drawings are as follows: 1-Clutch; 2-Mechanical pump; 3-External electronic pump; 4-Main oil line; 40-First oil line; 41-Second oil line; 42-Third oil line; 43-Fourth oil line; 44-Fifth oil line; 420-First branch line; 421-Second branch line; 422-Third branch line; 423-Fourth branch line; 424-Fifth branch line; 430-Sixth branch line; 431-Seventh branch line; 5-Cooling oil circuit; 50-Sixth oil circuit; 51-Seventh oil circuit; 52-Eighth oil circuit; 53-Ninth oil circuit; 510-Eighth branch circuit; 511-Ninth branch circuit; 520-Tenth branch circuit; 521-Eleventh branch circuit; 522-Twelfth branch circuit; 6-Solenoid switch valve; 7-Pressure regulating valve; 70-First control terminal; 71-Second control terminal; 8-Directional control valve; 80-Control terminal; 90-Suction filter; 91-Filter press; 92-Bypass valve; 93-First throttle orifice; 94-Second throttle orifice; 95-Third throttle orifice; 96-First safety valve; 97-Fourth throttle orifice; 98-First check valve; 99-Second check valve; 100-Oil cooler; 101-Second safety valve; 102-First cooling oil passage; 103-Second cooling oil passage; 104-Fifth throttle orifice; 105-Sixth throttle orifice; 106-Engine; 200-Transmission gear; 201-Transmission shaft; 202-Inner rotor; 203-Outer rotor; 204-Upper valve plate; 205-Intermediate partition plate; 206-Lower valve plate; 207-Electronic pump inlet; 208-Electronic pump outlet. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] As will be understood by those skilled in the art, existing valve body assembly designs can be divided into two categories. One category integrates the inner and outer rotors of both the high-pressure and low-pressure pumps into the valve body assembly, each driven by a separate motor, eliminating the need for gear drives. It also integrates an electromagnetic proportional valve and a pressure sensor. In this type of design, the high-pressure pump primarily controls the clutch engagement, and excess hydraulic oil, along with the hydraulic oil pumped by the low-pressure pump, can be used to cool and lubricate components such as the clutch, motor, and shaft gears. This type of design requires a dual-motor configuration, with the corresponding mechanical rotors integrated into a single valve body assembly. This necessitates a large layout space, and the use of an electromagnetic proportional valve and pressure sensor to regulate the clutch chamber oil pressure increases costs, complicates wiring harness layout, and raises both hardware and software design costs and control complexity.

[0026] Another type integrates both high-pressure and low-pressure mechanical pumps into the valve body assembly, driven by gear meshing within the transmission. In this approach, the high-pressure pump also controls clutch engagement, and excess hydraulic oil, along with the hydraulic oil pumped by the low-pressure pump, cools and lubricates components such as the clutch, motor, and shaft gears. This type of solution requires a dual-pump configuration integrated into a single valve body assembly, necessitating significant space requirements. Furthermore, since both mechanical pumps are driven by transmission gears, their speed cannot be freely controlled. At high speeds, the hydraulic oil supply exceeds demand, resulting in high energy consumption and low efficiency.

[0027] Based on this, please refer to Figures 1-3This utility model provides a hydraulic system for a transmission, including: a valve body assembly and an external electronic pump 3; the valve body assembly has a mechanical pump 2, a main oil circuit 4, and a cooling oil circuit 5; the mechanical pump 2 is connected to the control oil circuit of the clutch 1 through the main oil circuit 4 to control the engagement or disengagement of the clutch 1; the external electronic pump 3 is connected to the main oil circuit 4 through the cooling oil circuit 5 to supplement the oil supply to the valve body assembly when the oil supply from the mechanical pump 2 is insufficient. Thus, by externalizing the electronic pump, the space requirement for the valve body assembly is reduced, making the valve body assembly layout more flexible and reducing costs; at the same time, the external electronic pump 3 can achieve precise flow control, and can promptly supplement the missing oil when the oil supply from the mechanical pump 2 is insufficient, reducing overall energy consumption and further reducing costs.

[0028] Please refer to Figures 2-3 As an example, the hydraulic system of the aforementioned transmission may also include a transmission gear 200, a transmission shaft 201, an inner rotor 202, an outer rotor 203, an upper valve plate 204, an intermediate partition 205, a lower valve plate 206, an electronic pump inlet 207, and an electronic pump outlet 208. The inner rotor 202 and outer rotor 203 serve as the power source of the hydraulic system. Through the change in volume caused by the meshing of the inner and outer rotors, they generate oil suction and pressure actions, providing a stable pressure oil source for the entire hydraulic system. The transmission gear 200 transmits power through gear meshing and achieves speed reduction and torque amplification, amplifying a small input force to drive the valve opening and closing. The transmission shaft 201 can transmit the rotational power generated by the gear mechanism to the valve opening and closing components (such as gates or valve cores). The upper valve plate 204 is typically equipped with various control valves and solenoid valves, which can receive electrical signal commands and precisely control the oil circuits leading to various actuators (such as clutches and brakes); the intermediate partition plate 205 is located between the upper valve plate 204 and the lower valve plate 206, and has oil holes and channels, which are responsible for connecting, switching or isolating specific oil circuits between the upper valve plate 204 and the lower valve plate 206; the lower valve plate 206 typically contains basic valve bodies such as the main pressure regulating valve, which is responsible for establishing and stabilizing the basic pressure of the hydraulic system.

[0029] In this embodiment, both the electronic pump inlet 207 and the electronic pump outlet 208 are located on the lower valve plate 206. The external electronic pump 3 is connected to both the electronic pump inlet 207 and the electronic pump outlet 208 to replenish oil to the valve body assembly. Thus, the external electronic pump 3 is entirely located outside the valve body assembly, which integrates only a single mechanical pump. This results in a simple structure, requires less space, and reduces costs.

[0030] In an optional embodiment, the hydraulic system further includes a first cooling oil passage 102 and a second cooling oil passage 103; the main oil circuit 4 is a high-pressure oil circuit, which is mainly supplied with oil by the mechanical pump 2, and controls the internal pressure of the clutch 1 by supplying oil to the clutch 1, thereby realizing the disengagement or engagement of the clutch 1; the cooling oil circuit 5 is a low-pressure oil circuit, which is mainly supplied with oil by an external electric pump 3, and forms a cooling oil body through the oil cooler 100, and cools and lubricates components such as the clutch 1, electric motor, generator, and shaft gears through the first cooling oil passage 102 and the second cooling oil passage 103 respectively. In this embodiment, the external electric pump 3 is mainly used to replenish the oil body in the cooling oil circuit 5 to the valve body assembly to ensure the cooling and lubrication effect, thereby reducing energy consumption.

[0031] Specifically, such as Figure 1 As shown, the main oil circuit 4 mainly includes a first oil circuit 40, a second oil circuit 41, a third oil circuit 42, a fourth oil circuit 43, and a fifth oil circuit 44. The mechanical pump 2 is connected to the clutch 1 through the second oil circuit 41 and the third oil circuit 42. The cooling oil circuit 5 mainly includes a sixth oil circuit 50, a seventh oil circuit 51, an eighth oil circuit 52, and a ninth oil circuit 53. The external electronic pump 3 is connected to the first cooling oil passage 102 and the second cooling oil passage 103 through the sixth oil circuit 50, the seventh oil circuit 51, the eighth oil circuit 52, and the ninth oil circuit 53. In some embodiments, the main oil circuit 4 and the cooling oil circuit 5 may also be composed of other oil circuits depending on the actual situation; this embodiment does not impose such limitations.

[0032] Furthermore, the valve body assembly includes an electromagnetic switch valve 6, which is disposed on the main oil circuit 4 and located between the mechanical pump 2 and the clutch 1. The electromagnetic switch valve 6 is used to connect or disconnect the connection between the mechanical pump 2 and the clutch 1. Thus, in this embodiment, the electromagnetic switch valve 6 replaces the proportional pressure valve and pressure sensor commonly used in the prior art, and only performs the connection or disconnection of the main oil circuit 4 between the mechanical pump 2 and the clutch 1, reducing the requirements for current control. It also allows for a larger valve core clearance in the electromagnetic switch valve 6, reducing the anti-contamination requirements of the electromagnetic switch valve 6 and significantly improving the anti-contamination capability of the valve body assembly. At the same time, compared with the electromagnetic proportional valve, the electromagnetic switch valve 6 has a simpler structure and control method, and eliminates the need for a pressure sensor, further optimizing space, weight, and cost.

[0033] Specifically, in this embodiment, the electromagnetic switch valve 6 is controlled by an electrical signal. The electromagnetic switch valve 6 has a P port, an A port, and a T port. When the electromagnetic switch valve 6 is open, the P port and the A port are connected, and oil is supplied to the clutch 1 through the electromagnetic switch valve 6, and the clutch 1 is engaged. When the electromagnetic switch valve 6 is closed, the T port and the A port are connected, and the oil in the clutch 1 flows out of the valve body assembly through the T port, and the clutch 1 is disengaged.

[0034] As an optional embodiment, the valve body assembly includes a pressure regulating valve 7 and a first drive oil circuit; the pressure regulating valve 7 has a first control terminal 70; one end of the first drive oil circuit is connected to the main oil circuit 4, and the other end is connected to the first control terminal 70; the mechanical pump 2 supplies oil to the first control terminal 70 through the first drive oil circuit and drives the valve core of the pressure regulating valve 7 to move, thereby opening the oil inlet and outlet of the pressure regulating valve 7; the oil inlet of the pressure regulating valve 7 is connected to the main oil circuit 4, and the oil outlet of the pressure regulating valve 7 is connected to the cooling oil circuit 5. The oil in the main oil circuit 4 flows into the cooling oil circuit 5 through the pressure regulating valve 7 to reduce the pressure in the main oil circuit 4. In this way, the pressure regulating valve 7 can accurately regulate and control the working pressure in the valve body assembly. It can reduce and stabilize the high oil pressure generated by the oil pump to the pressure level required by the actuator, and can also limit the maximum oil pressure to prevent the internal pressure of the valve body assembly from being too high, thereby protecting the valve body and actuator from damage.

[0035] Specifically, in Figure 1 In the illustrated example, the first drive oil circuit is the second branch 421 of the third oil circuit 42. When the mechanical pump 2 delivers oil to the first control terminal 70 of the pressure regulating valve 7 through the second branch 421, the oil enters the valve body of the pressure regulating valve 7 and exerts a force on the valve core to push the valve core to move inside the valve body, so that the oil inlet and oil outlet of the pressure regulating valve 7 can be connected inside the valve body to form a passage.

[0036] Exemplary, in Figure 1 In this embodiment, the first control terminal 70 is located at the end of the pressure regulating valve 7. In other embodiments, the first control terminal 70 may also be located at the center of the pressure regulating valve 7. This embodiment does not limit this.

[0037] In some embodiments, the valve body assembly includes a second drive oil circuit; the pressure regulating valve 7 has a second control terminal 71, one end of the second drive oil circuit is connected to the main oil circuit 4, and the other end is connected to the second control terminal 71; when the solenoid switch valve 6 is open, a portion of the oil is supplied to the second control terminal 71 via the second drive oil circuit, and drives the valve core of the pressure regulating valve 7 to move, thereby closing the oil inlet of the pressure regulating valve 7. Optionally, the second control terminal 71 and the first control terminal 70 are disposed opposite to each other inside the valve body of the pressure regulating valve 7, so that after the oil enters the valve body through the second control terminal 71, it can generate a force opposite to that of the first control terminal 70, thereby driving the valve core to move in the opposite direction, thereby closing the oil inlet of the pressure regulating valve 7.

[0038] Specifically, such as Figure 1As shown, the second drive oil circuit is the seventh branch 431 in the fourth oil circuit 43. When the solenoid switch valve 6 is open, part of the oil flows directly to the clutch 1 and drives the clutch 1 to engage; part of the oil flows through the seventh branch 431 to the second control terminal 71 of the pressure regulating valve 7. The oil enters the valve body of the pressure regulating valve 7 and exerts a force on the valve core to push the valve core to move inside the valve body in the opposite direction, so that the valve core blocks the oil inlet of the pressure regulating valve 7.

[0039] Optional, in Figure 1 In this embodiment, the first control terminal 70 and the second control terminal 71 are respectively located at opposite ends of the pressure regulating valve 7. In other embodiments, the first control terminal 70 and the second control terminal 71 may also be located at the center or other positions of the pressure regulating valve 7. This embodiment does not impose any restrictions on this.

[0040] Exemplary, the hydraulic system includes a first cooling oil passage 102 and a second cooling oil passage 103, which are used to supply cooling oil to components in the hydraulic system. The valve body assembly includes an oil cooler 100, which is disposed on a cooling oil circuit 5. One end of the cooling oil circuit 5 is connected to a pressure regulating valve 7 and an external electric pump 3, and the other end is connected to the first cooling oil passage 102 and the second cooling oil passage 103. Thus, by supplying cooling oil to the first cooling oil passage 102 and the second cooling oil passage 103 through the cooling oil circuit 5, cooling and lubricating components such as the clutch 1, drive motor, generator, and shaft gears, the system can be cooled and de-cooled, reducing wear during operation and ensuring optimal system performance, thereby improving the efficiency of the power system.

[0041] As will be understood by those skilled in the art, the oil cooler 100 mainly works through heat exchange. The high-temperature oil flows through the pipes or heat dissipation fins inside the oil cooler 100, and the cooling medium flows through the outside of the pipes or heat dissipation fins, carrying away the heat of the oil and thus achieving cooling. The cooled oil then returns to the valve body assembly for circulation.

[0042] Please continue to refer to this. Figure 1The valve assembly includes a reversing valve 8 and a third drive oil circuit. The reversing valve 8 has a control terminal 80. One end of the third drive oil circuit is connected to the main oil circuit 4, and the other end is connected to the control terminal 80. The mechanical pump 2 supplies oil to the control terminal 80 through the third drive oil circuit and drives the valve core of the reversing valve 8 to move, thereby opening the oil inlet and outlet of the reversing valve 8. The cooling oil circuit 5 includes a first output section and a second output section. The first output section is connected to the first cooling oil passage 102, and the second output section is connected to the second cooling oil passage 103. The oil inlet of the reversing valve 8 is connected to the second output section, and the oil outlet of the reversing valve 8 is connected to the first output section, used to adjust the flow distribution between the first cooling oil passage 102 and the second cooling oil passage 103. Thus, by setting the reversing valve 8, the flow rate to the first cooling passage and the second cooling passage can be adjusted to achieve flow control and distribution. Among them, the first cooling oil passage 102 is connected to the generator, and the second cooling oil passage 103 is connected to the drive motor. Exemplarily, in Figure 1 In the middle, the first output section is the ninth oil line 53, and the second output section is the tenth branch 520 of the eighth oil line 52.

[0043] Specifically, such as Figure 1 As shown, the third drive oil circuit is the fourth branch 423 of the third oil circuit 42. The control end 80 of the reversing valve 8 is located at the end of the valve body of the reversing valve 8. After the mechanical pump 2 delivers oil to the valve body of the reversing valve 8 through the fourth branch 423 of the third oil circuit 42, the oil exerts a force on the valve core of the reversing valve 8 and pushes the valve core of the reversing valve 8 to move, so that the oil inlet and oil outlet of the reversing valve 8 can be connected inside the valve body to form a passage.

[0044] Preferably, the valve body assembly includes a first check valve 98 and a second check valve 99. The first check valve 98 is located between the oil outlet of the pressure regulating valve 7 and the cooling oil circuit 5, allowing unidirectional flow of oil through the oil outlet of the pressure regulating valve 7 to the cooling oil circuit 5. The second check valve 99 is located between the external electric pump 3 and the cooling oil circuit 5, allowing unidirectional flow of oil through the external electric pump 3 to the cooling oil circuit 5. The check valves maintain the pressure in the oil circuit, establish back pressure, and isolate the circuit, ensuring that the oil flows only in a specific direction and does not leak or flow back into other parallel oil circuits, thus ensuring the accuracy of control. At the same time, the check valves also prevent oil backflow, avoid unnecessary heat exchange, and ensure the efficient operation of the valve body assembly.

[0045] Optionally, the valve body assembly includes a first safety valve 96 and a second safety valve 101. The first safety valve 96 is connected to the main oil circuit 4. When the pressure in the main oil circuit 4 exceeds a predetermined pressure, the first safety valve 96 opens to discharge oil from the main oil circuit 4 into the valve body assembly. The second safety valve 101 is connected to the cooling oil circuit 5. When the pressure in the cooling oil circuit 5 exceeds a predetermined pressure, the first safety valve 96 opens to discharge oil from the cooling oil circuit 5 into the valve body assembly. The safety valves are designed to automatically open and release pressure when the pressure in the oil circuit abnormally rises and exceeds a specified limit, preventing damage to the power system from excessive pressure and ensuring the safe operation of the power system.

[0046] Specifically, when the pressure in the oil circuit is normal, the safety valve is kept closed by force (such as spring force), sealing the pressure of the valve body assembly. When the pressure in the oil circuit rises abnormally for some reason and exceeds the predetermined pressure of the safety valve, the oil pressure will overcome the spring force and push the valve core of the safety valve to open. At this time, the excess oil will flow out through the channel opened by the safety valve (usually flowing back to the oil pan) to quickly reduce the pressure in the oil circuit. When the pressure in the oil circuit drops back to the normal range, the spring force is greater than the oil circuit pressure, pushing the valve core to reset, the safety valve closes, and the valve body assembly returns to normal working state.

[0047] Please refer to Figure 1 The valve body assembly includes a filter press 91 and a bypass valve 92. The main oil circuit 4 has an oil supply branch. The filter press 91 is located on the main oil circuit 4, and the bypass valve 92 is located on the oil supply branch, forming a parallel connection with the main oil circuit 4. When the oil pressure in the main oil circuit 4 is greater than a predetermined pressure, the bypass valve 92 opens the oil supply branch. The design of the filter press 91 can keep the oil clean, extend the service life of the valve body assembly, and improve the reliability of the hydraulic system. When the filter element of the filter press 91 is clogged with impurities due to prolonged use, causing an excessive pressure difference, the bypass valve 92 can be opened, allowing the oil to flow through the oil supply branch to the main oil circuit 4 and continue to supply oil, thus avoiding more serious damage to the hydraulic system due to oil supply interruption.

[0048] Preferred, in Figure 1 In the example shown, the main oil passage 4 and the cooling oil passage 5 are also provided with multiple throttling orifices. As those skilled in the art will understand, a throttling orifice is a small hole with a fixed diameter. When the oil flows through this small hole, the oil will be resisted due to the sudden reduction in the flow area, which will cause the oil flow rate to increase and the pressure to decrease, thereby achieving control of the oil flow rate.

[0049] In another embodiment, this utility model provides a power system including an engine 106 and a hydraulic system for the transmission as described above. The engine 106 has an input shaft connected to a mechanical pump 2, and the engine 106 drives the mechanical pump 2 to operate via the input shaft. The mechanical pump 2 is arranged next to the input shaft of the engine 106 and is driven by a drive gear on the input shaft. The driving method in this embodiment eliminates the need for a dedicated oil pump drive motor and a complex oil pump controller design, achieving more precise and efficient control with only a simple mechanical structure. Furthermore, integrating the mechanical pump 2 into the valve body assembly optimizes space, weight, and cost.

[0050] The following will combine Figure 1 The oil supply routes in the valve body assembly under different modes will be further explained.

[0051] exist Figure 1 In the middle, the valve body assembly includes a mechanical pump 2, a main oil circuit 4, a cooling oil circuit 5, a solenoid switch valve 6, a pressure regulating valve 7, a reversing valve 8, a filter press 91, a bypass valve 92, a safety valve, a check valve, and a throttle orifice; the power system includes an external electronic pump 3, a clutch 1, an engine 106, and a suction filter 90.

[0052] The main oil circuit 4 consists of a first oil circuit 40, a second oil circuit 41, a third oil circuit 42, a fourth oil circuit 43, and a fifth oil circuit 44. The first oil circuit 40 is connected at one end to a suction filter 90, and at the other end to both a mechanical pump 2 and an external electronic pump 3, supplying hydraulic oil filtered by the suction filter 90 to both pumps. The second oil circuit 41 receives hydraulic oil pumped out by the mechanical pump 2 at one end, and forms a main circuit and a branch circuit at the other end. The main circuit connects to the filter press 91, and the branch circuit connects to a bypass valve 92. The second oil circuit 41 further filters the hydraulic oil through the filter press 91. When the pressure exceeds a set limit, the bypass valve 92 opens, allowing hydraulic oil to flow through the branch circuit. One end of the third oil passage 42 receives the hydraulic oil flowing from the filter press 91 and the bypass valve 92, and the other end forms the first branch 420, the second branch 421, the third branch 422, the fourth branch 423, and the fifth branch 424. The first branch 420 is connected to the P port of the solenoid valve 6 through the first throttle orifice 93; the second branch 421 is connected to the first control terminal 70 of the pressure regulating valve 7 through the second throttle orifice 94, thereby actuating the valve core of the pressure regulating valve 7 to move, thus... The inlet and outlet of the pressure regulating valve 7 are connected; the third branch 422 is connected to the inlet of the pressure regulating valve 7; the fourth branch 423 is connected to the control terminal 80 of the directional valve 8 through the third throttle orifice 95, so as to push the valve core of the directional valve 8 to move, so that the inlet and outlet of the directional valve 8 are connected; the fifth branch 424 is connected to the first safety valve 96. When the pressure of the third oil circuit 42 exceeds the set limit, the first safety valve 96 opens and releases the pressure of the third oil circuit 42. One end of the fourth oil circuit 43 receives the high-pressure oil flowing from port A of the solenoid valve 6, and the other end forms the sixth branch 430 and the seventh branch 431. The sixth branch 430 is connected to port C0 of the valve body assembly and leads to the clutch 1 chamber to control the engagement of the clutch 1. The seventh branch 431 is connected to the second control terminal 71 of the pressure regulating valve 7 through the fourth throttle orifice 97, so as to push the valve core of the pressure regulating valve 7 to move in the opposite direction, gradually closing the oil inlet of the pressure regulating valve 7, thereby regulating the pressure of the third oil circuit 42. One end of the fifth oil circuit 44 receives the hydraulic oil flowing from the outlet of the pressure regulating valve 7, and the other end is connected to the first check valve 98.

[0053] The cooling oil circuit 5 consists of a sixth oil circuit 50, a seventh oil circuit 51, an eighth oil circuit 52, and a ninth oil circuit 53. The sixth oil circuit 50 receives low-pressure oil flowing from the outlet of the external electronic pump 3 at one end, and is connected to the second check valve 99 at the other end. The seventh oil circuit 51 receives hydraulic oil flowing through the first check valve 98 and the second check valve 99 at one end, and forms an eighth branch 510 and a ninth branch 511 at the other end. The eighth branch 510 is connected to the inlet of the oil cooler 100; the ninth branch 511 is connected to the second safety valve 101. When the pressure in the seventh oil circuit 51 exceeds a set limit, the second safety valve 101 opens and releases the pressure in the seventh oil circuit 51. One end of the eighth oil passage 52 receives hydraulic oil from the outlet of the oil cooler 100, and the other end forms the tenth branch 520, the eleventh branch 521, and the twelfth branch 522. The tenth branch 520 is connected to the second cooling oil passage 103; the eleventh branch 521 is connected to the ninth oil passage 53 through the fifth throttle orifice 104; and the twelfth branch 522 is connected to the inlet of the directional valve 8. One end of the ninth oil passage 53 receives hydraulic oil flowing out from the outlet of the directional valve 8 and the fifth throttle orifice 104, and the other end is connected to the first cooling oil passage 102 through the sixth throttle orifice 105.

[0054] In one optional embodiment, the power system has a first mode, a second mode, and a third mode. The first mode is a pure electric mode, the second mode is a series mode, and the third mode is a parallel mode. In pure electric mode, the engine 106 does not operate, and the wheels are driven by a battery-powered motor, primarily used for urban congestion, short-distance commuting, and low-speed cruising. In series mode, the engine 106 only generates electricity and does not directly drive the wheels; the wheels are electrically driven by a battery-powered motor, primarily used for low-speed urban driving and situations where the battery is low on power. In parallel mode, both the engine 106 and the motor drive the wheels simultaneously, primarily used for high-speed overtaking, rapid acceleration, hill climbing, and high-speed cruising.

[0055] In one embodiment, when the power system is in pure electric mode, the main oil circuit 4 of the valve body assembly is connected to the external electric pump 3, and the external electric pump 3 is connected to the first cooling oil passage 102 and the second cooling oil passage 103 through the cooling oil circuit 5.

[0056] Specifically, when engine 106 is not operating and mechanical pump 2 remains closed, the second oil circuit 41, third oil circuit 42, fourth oil circuit 43, and fifth oil circuit 44 are shut off, and the inlets of pressure regulating valve 7 and reversing valve 8 are closed. The first oil circuit 40 supplies oil to the external electronic pump 3 separately. At this time, the external electronic pump 3 supplies oil to the sixth oil circuit 50 and enters the seventh oil circuit 51 through the second check valve 99. Due to the action of the first check valve 98, the seventh oil circuit 51 is disconnected from the fifth oil circuit 44. The oil body is connected to the oil cooler 100 through the eighth branch 510 of the seventh oil circuit 51. After passing through the oil cooler 100, part of the oil body is directly connected to the first low-pressure oil passage through the tenth branch 520 of the eighth oil circuit 52, and the other part is connected to the ninth oil circuit 53 through the fifth throttle orifice 104 in the eleventh branch 521. After entering the ninth oil circuit 53, it is connected to the second low-pressure oil passage through the sixth throttle orifice 105.

[0057] In another embodiment, when the power system is in series mode, the engine 106 drives the mechanical pump 2 to operate. The main oil circuit 4 is connected to the mechanical pump 2 and the external electronic pump 3 respectively. The electromagnetic switch valve 6 is closed. The mechanical pump 2 drives the valve core of the pressure regulating valve 7 through the first drive oil circuit and opens the oil inlet and outlet of the pressure regulating valve 7. The oil flowing through the main oil circuit 4 flows into the cooling oil circuit 5 through the pressure regulating valve 7 and mixes with the oil provided by the external electronic pump 3 in the cooling oil circuit 5, and flows together to the first cooling oil passage 102 and the second cooling oil passage 103. The mechanical pump 2 drives the valve core of the reversing valve 8 through the third drive oil circuit and opens the oil inlet and outlet of the reversing valve 8 to distribute the oil volume of the first cooling oil passage 102 and the second cooling oil passage 103.

[0058] Specifically, engine 106 operates, driving mechanical pump 2 via input shaft. Electromagnetic switch valve 6 closes, P port and A port are shut off, and fourth oil circuit 43 is closed. Mechanical pump 2 drives the valve core of pressure regulating valve 7 to move via the second branch 421 of third oil circuit 42, thus opening the inlet and outlet of pressure regulating valve 7. Simultaneously, mechanical pump 2 drives the valve core of directional valve 8 to move via the fourth branch 423 of third oil circuit 42, thus opening the inlet and outlet of directional valve 8. First oil circuit 40 supplies oil to mechanical pump 2 and external electronic pump 3 respectively. A portion of the oil flows through the inlet and outlet of mechanical pressure regulating valve 7 to fifth oil circuit 44, and another portion flows through external electronic pump 3 to sixth oil circuit 50. Oil passage 44 and the sixth oil passage 50 are connected to the seventh oil passage 51 through the first check valve 98 and the second check valve 99, respectively. After the oil flows into the seventh oil passage 51, it flows into the oil cooler 100 through the eighth branch 510. After passing through the oil cooler 100, part of the oil flows directly into the first low-pressure oil passage through the tenth branch 520. Another part of the oil flows into the ninth oil passage 53 through the eleventh branch 521 and the fifth throttle orifice 104. In the ninth oil passage 53, it flows into the second low-pressure oil passage through the sixth throttle orifice 105. A third part of the oil flows into the reversing valve 8 through the twelfth branch 522. After flowing out of the reversing valve 8, it flows into the ninth oil passage 53 and finally connects to the second low-pressure oil passage through the sixth throttle orifice 105.

[0059] In another embodiment, when the power system is in parallel mode, the engine 106 drives the mechanical pump 2 to operate. The main oil circuit 4 is connected to the mechanical pump 2 and the external electronic pump 3 respectively. The solenoid switch valve 6 is opened, the mechanical pump 2 drives the clutch 1 to engage, and drives the valve core of the pressure regulating valve 7 through the second drive oil circuit to close the oil inlet of the pressure regulating valve 7. The oil supplied by the external electronic pump 3 flows to the first cooling oil passage 102 and the second cooling oil passage 103 through the cooling oil circuit 5. The mechanical pump 2 drives the valve core of the reversing valve 8 through the third drive oil circuit and opens the oil inlet and outlet of the reversing valve 8 to distribute the oil volume of the first cooling oil passage 102 and the second cooling oil passage 103. When the power system exits the parallel mode, the solenoid switch valve 6 is turned off and the clutch 1 is disengaged.

[0060] Specifically, engine 106 operates, driving mechanical pump 2 via input shaft. Electromagnetic switch valve 6 opens, connecting ports P and A, and opening the fourth oil circuit 43. Mechanical pump 2 drives the valve core of directional valve 8 via the fourth branch 423 of the third oil circuit 42, opening the inlet and outlet of directional valve 8. The first oil circuit 40 supplies oil to mechanical pump 2 and external electronic pump 3 respectively. A portion of the oil, after passing through electromagnetic switch valve 6, connects to clutch 1 via the sixth branch 430 of the fourth oil circuit 43, controlling clutch 1 to engage. Simultaneously, another portion of the oil flows into the second control terminal 71 of pressure regulating valve 7 via the seventh branch 431 of the fourth oil circuit 43, controlling the inlet of pressure regulating valve 7 to close. The remaining portion of the oil flows through external electronic pump 3... In the sixth oil circuit 50, the sixth oil circuit 50 is connected to the seventh oil circuit 51 through the second one-way valve 99, and is disconnected from the fifth oil circuit 44 by the action of the first one-way valve 98. The oil flows through the eighth branch 510 to connect with the oil cooler 100. After passing through the oil cooler 100, part of the oil flows directly to the first low-pressure oil passage through the tenth branch 520; another part flows through the eleventh branch 521, through the fifth throttle orifice 104, to the ninth oil circuit 53, and in the ninth oil circuit 53, it connects with the second low-pressure oil passage through the sixth throttle orifice 105; and yet another part flows through the twelfth branch 522 into the reversing valve 8, and after flowing out of the reversing valve 8, it flows into the ninth oil circuit 53, and finally connects with the second low-pressure oil passage through the sixth throttle orifice 105. When the power system exits the parallel mode, the solenoid switch valve 6 is closed, the P port and A port are disconnected, and the T port and A port are connected. The oil in the clutch 1 flows out of the valve body assembly through the T port, and the clutch 1 is disengaged. In another embodiment, the present invention also provides a vehicle including the power system described above. Thus, by using the aforementioned power system, integrating the mechanical pump 2 into the valve body assembly and externally connecting the electronic pump reduces the space requirements of the valve body assembly, making its arrangement more flexible and effectively reducing costs. Simultaneously, the external electronic pump enables precise flow control, replenishing the missing oil in a timely manner when the mechanical pump 2 is insufficient, thereby reducing overall energy consumption and further lowering costs.

[0061] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications or equivalent substitutions made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hydraulic system for a transmission, characterized in that, include: The valve body assembly includes a mechanical pump, a main oil passage, and a cooling oil passage; the mechanical pump is connected to the clutch control oil passage through the main oil passage to control the engagement or disengagement of the clutch; An external electronic pump is connected to the main oil circuit through the cooling oil circuit to supplement the oil supply to the valve body assembly when the mechanical pump's oil supply is insufficient.

2. The hydraulic system of the transmission according to claim 1, characterized in that, The valve assembly includes an electromagnetic switch valve, which is disposed on the main oil line and located between the mechanical pump and the clutch. The electromagnetic switch valve is used to connect or disconnect the connection between the mechanical pump and the clutch.

3. The hydraulic system of the transmission according to claim 2, characterized in that, The valve body assembly further includes a pressure regulating valve and a first drive oil circuit; the pressure regulating valve has a first control terminal; One end of the first drive oil circuit is connected to the main oil circuit, and the other end is connected to the first control terminal; The mechanical pump supplies oil to the first control terminal through the first drive oil circuit and drives the valve core of the pressure regulating valve to move, so as to open the oil inlet and oil outlet of the pressure regulating valve. The oil inlet of the pressure regulating valve is connected to the main oil circuit, and the oil outlet of the pressure regulating valve is connected to the cooling oil circuit. The oil in the main oil circuit flows into the cooling oil circuit through the pressure regulating valve to reduce the pressure in the main oil circuit.

4. The hydraulic system of the transmission according to claim 3, characterized in that, The valve body assembly also includes a second drive oil circuit; The pressure regulating valve also has a second control terminal, one end of the second drive oil circuit is connected to the main oil circuit, and the other end is connected to the second control terminal; When the electromagnetic switch valve is opened, a portion of the oil is supplied to the second control terminal via the second drive oil circuit, and drives the valve core of the pressure regulating valve to move, thereby closing the oil inlet of the pressure regulating valve.

5. The hydraulic system of the transmission according to claim 4, characterized in that, The hydraulic system further includes a first cooling oil passage and a second cooling oil passage, which are respectively used to deliver cooling oil to the components in the hydraulic system; the valve body assembly also includes an oil cooler. The oil cooler is installed on the cooling oil circuit. One end of the cooling oil circuit is connected to the pressure regulating valve and the external electronic pump, and the other end is connected to the first cooling oil passage and the second cooling oil passage.

6. The hydraulic system of the transmission according to claim 5, characterized in that, The valve body assembly also includes a reversing valve and a third drive oil circuit; the reversing valve has a control end; One end of the third drive oil circuit is connected to the main oil circuit, and the other end is connected to the control terminal; The mechanical pump supplies oil to the control terminal through the third drive oil circuit and drives the valve core of the reversing valve to move, so as to open the oil inlet and oil outlet of the reversing valve. The cooling oil circuit includes a first output section and a second output section, wherein the first output section is connected to the first cooling oil passage and the second output section is connected to the second cooling oil passage; The oil inlet of the reversing valve is connected to the second output section, and the oil outlet of the reversing valve is connected to the first output section, which is used to adjust the flow distribution between the first cooling oil passage and the second cooling oil passage.

7. The hydraulic system of the transmission according to claim 6, characterized in that, The hydraulic system also includes a suction filter. One end of the main oil circuit is connected to the suction filter, and the other end is connected to the mechanical pump and / or the external electronic pump, respectively, for providing filtered oil to the mechanical pump and / or the external electronic pump. In the first mode, the main oil circuit is connected to the external electric pump, and the external electric pump is connected to the first cooling oil passage and the second cooling oil passage respectively through the cooling oil circuit; wherein the first mode is the vehicle's power system in pure electric mode.

8. The hydraulic system of the transmission according to claim 6, characterized in that, The hydraulic system also includes a suction filter. One end of the main oil circuit is connected to the suction filter, and the other end is connected to the mechanical pump and / or the external electronic pump, respectively, for providing filtered oil to the mechanical pump and / or the external electronic pump. In the second mode, the mechanical pump is driven by the vehicle engine, the main oil circuit is connected to the mechanical pump and the external electronic pump respectively, the electromagnetic switch valve is closed, and the mechanical pump drives the valve core of the pressure regulating valve through the first drive oil circuit, and opens the oil inlet and outlet of the pressure regulating valve; wherein the second mode is the vehicle's power system in series mode; The oil flowing through the main oil circuit flows into the cooling oil circuit via the pressure regulating valve, where it mixes with the oil supplied by the external electronic pump and flows together into the first and second cooling oil passages. The mechanical pump drives the valve core of the reversing valve through the third drive oil circuit and opens the inlet and outlet of the reversing valve to distribute the oil volume of the first and second cooling oil passages.

9. The hydraulic system of the transmission according to claim 6, characterized in that, The hydraulic system includes a suction filter, one end of the main oil circuit is connected to the suction filter, and the other end is connected to the mechanical pump and / or the external electronic pump respectively, for providing filtered oil to the mechanical pump and / or the external electronic pump respectively; In the third mode, the mechanical pump is driven by the vehicle engine, the main oil circuit is connected to the mechanical pump and the external electronic pump respectively, the electromagnetic switch valve is opened, the mechanical pump drives the clutch to engage, and drives the valve core of the pressure regulating valve through the second drive oil circuit to close the oil inlet of the pressure regulating valve; wherein the third mode is the vehicle's power system in parallel mode; The oil supplied by the external electronic pump flows through the cooling oil circuit to the first cooling oil passage and the second cooling oil passage; the mechanical pump drives the valve core of the reversing valve through the third drive oil circuit and opens the oil inlet and outlet of the reversing valve to distribute the oil volume of the first cooling oil passage and the second cooling oil passage. When the vehicle's power system exits the third mode, the electromagnetic switch valve is turned off, and the clutch is disengaged.

10. The hydraulic system of the transmission according to claim 3, characterized in that, The valve assembly further includes a first check valve and a second check valve. The first check valve is disposed between the oil outlet of the pressure regulating valve and the cooling oil circuit, allowing unidirectional flow of oil through the oil outlet of the pressure regulating valve to the cooling oil circuit. The second check valve is disposed between the external electronic pump and the cooling oil circuit, allowing unidirectional flow of oil through the external electronic pump to the cooling oil circuit. And / or, The valve body assembly further includes a first safety valve and a second safety valve. The first safety valve is connected to the main oil circuit and opens when the pressure in the main oil circuit exceeds a predetermined pressure, thereby discharging oil from the main oil circuit into the valve body assembly. The second safety valve is connected to the cooling oil circuit and opens when the pressure in the cooling oil circuit exceeds a predetermined pressure, thereby discharging oil from the cooling oil circuit into the valve body assembly. And / or, The valve assembly includes a filter press and a bypass valve. The main oil circuit has an oil supply branch. The filter press is located on the main oil circuit, and the bypass valve is located on the oil supply branch. The oil supply branch is connected in parallel with the main oil circuit. When the oil pressure in the main oil circuit is greater than a predetermined pressure, the bypass valve opens the oil supply branch.

11. A power system, characterized in that, Includes an engine and a hydraulic system for a transmission as described in any one of claims 1 to 10; The engine has an input shaft connected to the mechanical pump, and the engine drives the mechanical pump to operate through the input shaft.

12. A vehicle, characterized in that, Including the power system as described in claim 11.

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