Hydraulic system for a hybrid transmission

Abstract

The application belongs to the technical field of hybrid power assemblies, and particularly relates to a kind of hybrid power gearbox hydraulic systems, including lubrication cooling subsystem, clutch control system and oil supply subsystem, lubrication cooling subsystem includes oil cooler and multiple cooling lubrication throttle holes, multiple cooling lubrication throttle holes are connected with the oil cooler by oil circuit;Clutch control system includes clutch C1, proportional electromagnetic pressure regulating valve, filter screen, constant pressure reducing valve and high pressure filter, the clutch C1 is connected with proportional electromagnetic pressure regulating valve by oil circuit, the proportional electromagnetic pressure regulating valve is connected with constant pressure reducing valve by oil circuit, the constant pressure reducing valve is connected with the high pressure filter by oil circuit;First electronic pump and second electronic pump of the application work independently, and oil supply is carried out respectively according to system requirement, control is more flexible;Second electronic pump stops working when separation clutch C1 does not work, realizes intermittent work of second electronic pump, reduces system loss, and improves system efficiency.

Description

Technical Field

[0001] This invention relates to the field of hybrid powertrain technology, and more particularly to a hydraulic system for a hybrid power transmission. Background Technology

[0002] With the continuous advancement of new energy vehicles, the market demand for hybrid power systems, as a form of new energy vehicle, has been increasing year by year. Hybrid power systems have various layout designs, with hydraulically controlled wet clutches being a relatively mature one. This design can meet multiple driving conditions, including pure electric driving, series driving, high-speed engine direct drive, and parallel driving, ensuring that both the electric motor and engine operate at high efficiency, ultimately achieving low fuel consumption, low emissions, and long driving range. It offers good power and economy at a relatively low cost.

[0003] The existing electronic pump operates continuously, which greatly affects its service life. It cannot adjust the oil supply flow according to different operating conditions of the transmission, and thus cannot meet the demand.

[0004] To address the aforementioned issues, this application proposes a hydraulic system for a hybrid power transmission. Summary of the Invention

[0005] (a) Purpose of the invention

[0006] To address the technical problems existing in the background art, the present invention proposes a hydraulic system for a hybrid power transmission.

[0007] (II) Technical Solution

[0008] To address the aforementioned problems, the present invention provides a hydraulic system for a hybrid power transmission, comprising a lubrication and cooling subsystem, a clutch control system, and an oil supply subsystem. The lubrication and cooling subsystem includes an oil cooler and multiple cooling and lubrication throttling orifices, wherein the multiple cooling and lubrication throttling orifices are connected to the oil cooler via oil passages.

[0009] The clutch control system includes a clutch C1, a proportional electromagnetic pressure regulating valve, a filter screen, a setpoint pressure reducing valve, and a high-pressure filter. The clutch C1 is connected to the proportional electromagnetic pressure regulating valve through an oil circuit. The proportional electromagnetic pressure regulating valve is connected to the setpoint pressure reducing valve through an oil circuit. The setpoint pressure reducing valve is connected to the high-pressure filter through an oil circuit.

[0010] The oil supply subsystem includes an oil pump assembly, a suction filter, and an oil tank. The oil cooler and high-pressure filter are connected to the oil pump assembly via oil circuits. The oil pump assembly is connected to the suction filter, and the suction filter is connected to the oil tank.

[0011] Furthermore, the clutch control system also includes an accumulator, which is installed in the oil line between the clutch C1 and the proportional electromagnetic pressure regulating valve.

[0012] Furthermore, the clutch control system also includes a pressure sensor installed in the oil line between the clutch C1 and the proportional electromagnetic pressure regulating valve.

[0013] Furthermore, a temperature sensor is installed inside the fuel tank.

[0014] Furthermore, four cooling and lubrication throttling orifices are provided, which are respectively connected to the LUB oil passage, C1 oil passage, EM1 oil passage and EM2 oil passage through oil passages.

[0015] Furthermore, the oil pump assembly includes a first electronic pump and a second electronic pump. The first electronic pump is connected to the oil cooler via an oil circuit, and the second electronic pump is connected to the high-pressure filter via an oil circuit.

[0016] Furthermore, the oil pump assembly includes a first mechanical pump and a third electronic pump. The first mechanical pump is connected to the oil cooler via an oil circuit, and the third electronic pump is connected to the high-pressure filter via an oil circuit. Two suction filters are provided, which are respectively connected to the first mechanical pump and the third electronic pump.

[0017] Furthermore, a pressure relief valve is connected in parallel to the oil circuit of the first mechanical pump.

[0018] Furthermore, a safety valve is connected to the end of the high-pressure filter.

[0019] The above-described technical solution of the present invention has the following beneficial technical effects:

[0020] This invention incorporates a high-pressure filter, which offers higher filtration accuracy than a suction filter, resulting in higher cleanliness of the high-pressure oil flowing through the pressure reducing valve and the downstream proportional valve. This reduces the risk of jamming in the set-value pressure reducing valve and the proportional electromagnetic pressure regulating valve. After being filtered by the high-pressure filter and passing through the set-value pressure reducing valve, the high-pressure oil pressure is stabilized at a relatively stable fixed value.

[0021] Advantages of the clutch control subsystem of the present invention: The subsystem is equipped with a small filter screen at the inlet and outlet of the proportional electromagnetic pressure regulating valve, which improves the cleanliness of the hydraulic oil entering and exiting the clutch cavity and avoids the spool valve from getting stuck due to impurities.

[0022] In this invention, both the first and second electronic pumps operate independently, supplying oil according to system requirements, thus providing more flexible control. When the disengagement clutch C1 is not in operation, the second electronic pump stops working, achieving intermittent operation of the second electronic pump, reducing system losses, and improving system efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of a hybrid power transmission hydraulic system of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of a hybrid power transmission hydraulic system of the present invention.

[0025] In the picture:

[0026] 1. Lubrication and Cooling Subsystem; 101. Oil Cooler; 102. Cooling and Lubrication Throttling Orifice; 103. LUB Oil Circuit; 104. C1 Oil Circuit; 105. EM1 Oil Circuit; 106. EM2 Oil Circuit; 2. Clutch Control System; 201. Clutch C1; 202. Accumulator; 203. Proportional Electromagnetic Pressure Regulator; 204. Filter Screen; 205. Setpoint Pressure Reducing Valve; 206. High Pressure Filter; 207. Safety Valve; 208. Pressure Sensor; 3. Oil Supply Subsystem; 301. First Electronic Pump; 302. Second Electronic Pump; 303. Suction Filter; 304. Oil Tank; 305. Temperature Sensor; 306. First Mechanical Pump; 307. Third Electronic Pump; 308. Pressure Relief Valve. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0028] Example 1: As Figure 1 As shown, the present invention provides a hydraulic system for a hybrid power transmission, including a lubrication and cooling subsystem 1, a clutch control system 2, and an oil supply subsystem 3. The lubrication and cooling subsystem 1 includes an oil cooler 101 and a plurality of cooling and lubrication throttling orifices 102, and the plurality of cooling and lubrication throttling orifices 102 are connected to the oil cooler 101 through an oil circuit.

[0029] The clutch control system 2 includes a clutch C1 201, a proportional electromagnetic pressure regulating valve 203, a filter screen 204, a setpoint pressure reducing valve 205, and a high-pressure filter 206. The clutch C1 201 is connected to the proportional electromagnetic pressure regulating valve 203 through an oil circuit. The proportional electromagnetic pressure regulating valve 203 is connected to the setpoint pressure reducing valve 205 through an oil circuit. The setpoint pressure reducing valve 205 is connected to the high-pressure filter 206 through an oil circuit.

[0030] The oil supply subsystem 3 includes an oil pump group, a suction filter 303, and an oil tank 304. The oil cooler 101 and the high-pressure filter 206 are connected to the oil pump group through an oil circuit. The oil pump group is connected to the suction filter 303, and the suction filter 303 is connected to the oil tank 304.

[0031] In this embodiment, it should be noted that, as Figure 1 As shown, the clutch control system 2 also includes an accumulator 202, which is installed in the oil line between the clutch C1 201 and the proportional electromagnetic pressure regulating valve 203.

[0032] In this embodiment, it should be noted that, as Figure 1 As shown, the clutch control system 2 also includes a pressure sensor 208, which is installed in the oil line between the clutch C1 201 and the proportional electromagnetic pressure regulating valve 203.

[0033] In this embodiment, it should be noted that, as Figure 1 As shown, a temperature sensor 305 is installed inside the oil tank 304.

[0034] In this embodiment, it should be noted that, as Figure 1 As shown, the cooling and lubrication throttling orifice 102 is provided with four holes, which are respectively connected to the LUB oil passage 103, C1 oil passage 104, EM1 oil passage 105 and EM2 oil passage 106 through oil passages.

[0035] In this embodiment, it should be noted that, as Figure 1 As shown, a safety valve 207 is connected to the end of the high-pressure filter 206.

[0036] In this embodiment, it should be noted that, as Figure 1 As shown, the oil pump assembly includes a first electronic pump 301 and a second electronic pump 302. The first electronic pump 301 is connected to the oil cooler 101 through an oil circuit, and the second electronic pump 302 is connected to the high-pressure filter 206 through an oil circuit.

[0037] Clutch C1 201 is controlled by a proportional electromagnetic pressure regulating valve 203 to meet the pressure requirements of the clutch under various operating conditions. An accumulator 202 and a pressure sensor 208 are added to the oil circuit at the rear end of the proportional electromagnetic pressure regulating valve 203. The accumulator 202 can absorb oil pressure fluctuations, thereby achieving smooth engagement and disengagement of clutch C1 201. The pressure sensor 208 can monitor the real-time pressure of the clutch, enabling closed-loop control of the system and making the control more precise.

[0038] Lubrication and cooling subsystem: Composed of oil cooler 101 and cooling and lubrication throttling orifice 102, it can achieve sufficient cooling and lubrication of gearbox bearings, gears, clutches, motors and synchronizers, so that the components of the entire gearbox can work within a reasonable temperature range;

[0039] Oil supply subsystem: This subsystem mainly consists of oil tank 304, temperature sensor 305, suction filter 303, first electronic pump 301, second electronic pump 302, and safety valve 207. The first electronic pump 301 and second electronic pump 302 draw oil from oil tank 304 through suction filter 303 to supply oil to the entire hydraulic system. The safety valve ensures that the entire system operates within a reasonable pressure range, protecting the entire hydraulic system.

[0040] The main function of oil tank 304 is to provide oil for the entire system.

[0041] The main function of the suction filter 303 is to filter impurities in the oil, providing the entire system with a high degree of cleanliness, preventing impurities from entering the oil pump assembly and causing pump wear; preventing impurities from entering the clutch control subsystem and causing valve core jamming; and preventing impurities from entering the lubrication and cooling subsystem and causing wear on components.

[0042] In hydraulic systems, the viscosity of the hydraulic fluid varies with temperature, significantly impacting the entire control system. Therefore, monitoring the temperature of the entire system is crucial. The primary function of temperature sensor 305 is to monitor the temperature of the entire hydraulic system, providing parameters for the control of the oil pump assembly and the clutch proportional valve. In electronic pump control, the pump speed is adjusted according to different temperature ranges.

[0043] The main function of a safety valve is to release oil in a timely manner when abnormal high pressure occurs in the system, so that the system operates within a reasonable pressure range and protects the safety of the entire hydraulic system.

[0044] Lubrication and cooling subsystem:

[0045] The first electronic pump 301 draws oil from the oil tank 305 through the suction filter 303 to supply oil to the gearbox lubrication and cooling system. This system mainly consists of cooling and lubrication oil circuits to LUB, C1, EM1, and EM2. After passing through the outlet of the first electronic pump 301, the oil reaches the oil cooler 101. After cooling, the lubricating and cooling oil is divided into four paths: one for cooling motor EM1, one for cooling motor EM2, one for cooling clutch C1 201, and one for the LUB lubrication oil circuit. The flow rate of the lubricating and cooling oil into the gearbox is mainly distributed by throttling orifices located in various pipelines of the gearbox. The size of the cooling and lubrication throttling orifice 102 adjusts the flow rate distribution to different lubrication and cooling points. Cooling and lubrication throttling orifices 102 are provided in the cooling oil circuits of C1, EM1, and EM2 to distribute the cooling flow to EM1 and EM2 respectively. The LUB oil circuit also has cooling and lubrication throttling orifices 102 to lubricate various lubrication points such as synchronizers, bearings, and gears.

[0046] Clutch actuator subsystem:

[0047] The second electronic pump 302 draws oil from the oil tank 305 through the suction filter 303 to supply oil to the clutch actuation subsystem of the transmission. The clutch control subsystem is supplied with oil independently by the second electronic pump 302. When engine intervention is not required, the clutch is in the disengaged state, and the second electronic pump 302 stops working.

[0048] This subsystem is equipped with a high-pressure filter 206, which has a higher filtration accuracy than the suction filter 303, ensuring higher cleanliness of the high-pressure oil flowing through the pressure reducing valve and the downstream proportional valve, thus reducing the risk of jamming in the setpoint pressure reducing valve 205 and the proportional solenoid pressure regulating valve 203. After being filtered by the high-pressure filter 206, the high-pressure oil passes through the setpoint pressure reducing valve 205, stabilizing the oil pressure at a relatively stable fixed value. The setpoint pressure reducing valve 205 is normally open when not in operation. When the setpoint pressure reducing valve 205 is in operation, hydraulic oil flows through it, and a portion of the oil acts on the pilot end of the valve. The hydraulic pressure generated at the pilot end interacts with the spring force at the spring end of the pressure reducing valve, ultimately achieving dynamic equilibrium, and the downstream pressure of the setpoint pressure reducing valve 205 reaches a relatively stable fixed value. When the second electronic pump 302 rotates at a high speed, the flow rate through the constant pressure reducing valve 205 is also large, and the pressure before the constant pressure reducing valve 205 is high. Due to the balance of forces at both ends of the constant pressure reducing valve 205 in the axial direction, the constant pressure reducing valve 205 moves to the left, and the opening of the constant pressure reducing valve 205 decreases. A portion of the oil is supplied to the lubrication circuit through the oil circuit, which achieves the effect of efficient utilization. A portion of the oil is continuously supplied to the rear clutch after passing through the constant pressure reducing valve 205, so that the pressure at the rear of the constant pressure reducing valve 205 is stabilized at a relatively stable fixed value.

[0049] The clutch C1 201 is controlled by a proportional electromagnetic pressure regulating valve 203, also known as a VFS solenoid valve, which is characterized by precise control of pressure and flow. Hydraulic oil passing through the setpoint pressure reducing valve 205 is filtered through a filter before reaching the clutch control valve VFS. After passing through the control valve VFS, the hydraulic oil is further filtered by filter 204 before reaching clutch C1 201. The main function of filter 204 is to ensure that when the clutch is disengaged, the hydraulic oil draining from the clutch piston chamber passes through this filter before draining through the clutch control valve VFS. This ensures that the clutch control valve is not blocked by impurities during draining. A feedback circuit is provided at the rear end of the clutch control valve VFS, i.e., a feedback oil path is provided at the spring end. This improves the accuracy of clutch engagement and disengagement control when the solenoid valve is in operation. Simultaneously, an accumulator is located at the rear end of the clutch control valve VFS. This accumulator absorbs oil vibrations and hydraulic shocks caused by fluctuations in the main oil circuit, making the clutch engagement and disengagement states smoother. A pressure sensor 208 is installed near the clutch piston chamber in the control oil circuit. The measured pressure value is closer to the actual value of the clutch control pressure, providing more accurate data support for software control.

[0050] The VFS solenoid valve core spring mainly serves a reset function. Its pressure control principle is as follows: hydraulic oil at port A is connected to one end of the valve core through the feedback oil circuit, and electromagnetic force acts on the other end of the valve core. The hydraulic pressure and electromagnetic force are compared with each other in real time to control the relative position of the valve core and the valve sleeve, which determines whether the solenoid valve P port is connected to port A or closed. The magnitude of the electromagnetic force is controlled by the magnitude of the current, thereby controlling the maximum pressure at port A, realizing feedback control, and achieving the transmission of different torques of the clutch.

[0051] Advantages of the clutch control subsystem:

[0052] The subsystem has a small filter screen 204 at the oil inlet and outlet of the proportional electromagnetic pressure regulating valve 203, which improves the cleanliness of the hydraulic oil in the clutch chamber and avoids the spool valve from getting stuck due to impurities.

[0053] The subsystem has an accumulator 202 installed in the oil circuit leading to the clutch chamber, which avoids hydraulic shock caused by fluctuations in the oil circuit during the clutch engagement process.

[0054] The clutch control spool valve has a feedback oil circuit at the spring end, which makes the spring force, feedback pressure and electromagnetic force form a dynamic balance, and the clutch pressure can be controlled in a smooth curve linear control.

[0055] The pressure sensor 208 is installed, and the measured pressure value is closer to the true value of the clutch pressure, providing a reliable closed-loop control for the TCU to control the clutch accurately.

[0056] The subsystem is equipped with a pressure reducing valve 205, which ensures that the pressure supplied to the clutch P port is always at a stable value, thus improving the accuracy of control.

[0057] Advantages of the lubrication and cooling subsystem:

[0058] After passing through the oil cooler 101, the lubricating and cooling oil lubricates and cools the gearbox components, especially the dual motors and the clutch, thus improving the lubrication and cooling effect.

[0059] The flow rate at each lubrication point is controlled by the cooling lubrication throttling orifice 102, which reduces costs.

[0060] advantage:

[0061] In this subsystem, the first electronic pump 301 and the second electronic pump 302 both operate independently, supplying oil according to system requirements, thus providing more flexible control.

[0062] When the disengagement clutch C1 201 is not working, the second electronic pump 302 stops working, realizing the intermittent operation of the second electronic pump 302, reducing system losses and improving system efficiency.

[0063] Clutch control subsystem:

[0064] The pressure reducing valve 205 can provide stable oil pressure to the clutch control subsystem when the second electronic pump 302 is running at a high speed, and excess oil is released back to the oil tank.

[0065] Example 2: As Figure 2 As shown, the oil pump assembly includes a first mechanical pump 306 and a third electronic pump 307. The first mechanical pump 306 is connected to the oil cooler 101 through an oil circuit, and the third electronic pump 307 is connected to the high-pressure filter 206 through an oil circuit. Two suction filters 303 are provided, which are respectively connected to the first mechanical pump 306 and the third electronic pump 307.

[0066] In this embodiment, it should be noted that, as Figure 2 As shown, a pressure relief valve 308 is connected in parallel on the oil circuit of the first mechanical pump 306.

[0067] The difference between this embodiment and Embodiment 1 lies in the oil supply subsystem. The rest of the components are the same as in Embodiment 1 and will not be repeated here.

[0068] Fuel supply subsystem:

[0069] The subsystem mainly consists of an oil tank 304, two suction filters 303, a first mechanical pump 306, a third electronic pump 307, and a pressure relief valve 308.

[0070] The operation of the third electronic pump 307 is the same as that in Example 1.

[0071] The first mechanical pump 306 operates as follows: Driven by the input shaft, the first mechanical pump 306 provides lubricating and cooling oil to the lubrication and cooling subsystem. The displacement of the first mechanical pump 306 is determined based on system requirements. When the input shaft speed is high, the output flow of the first mechanical pump 306 is large. Since the oil cooler 101 has a certain pressure resistance range, a pressure relief valve 308 is provided to ensure that the oil pressure supplied to the lubrication and cooling subsystem is always maintained within a certain pressure range. When the pressure exceeds the set pressure, the oil acts on the pilot end of the pressure relief valve 308, pushing the pressure relief valve 308 downward. The pressure relief valve 308 operates in the upper position, and the excess oil is discharged to the oil inlet between the first mechanical pump 306 and the suction filter 303.

[0072] Advantages: When the pump is working and drawing oil, there is some power consumption as it passes through the suction filter 303. When the first mechanical pump 306 is at a relatively high speed, excess oil passes through the pressure relief valve to the oil inlet between the first mechanical pump 306 and the suction filter 303. This part of the oil has already been filtered by the suction filter 303 and is a relatively clean oil. Since the oil intake at the oil inlet is constant at a fixed speed, some oil does not need to be filtered again, thereby improving the efficiency of the entire system.

[0073] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic system for a hybrid power transmission, comprising a lubrication and cooling subsystem (1), a clutch control system (2), and an oil supply subsystem (3), characterized in that, The lubrication and cooling subsystem (1) includes an oil cooler (101) and a plurality of cooling and lubrication throttling orifices (102), wherein the plurality of cooling and lubrication throttling orifices (102) are connected to the oil cooler (101) through an oil passage; The clutch control system (2) includes a clutch C1 (201), a proportional electromagnetic pressure regulating valve (203), a filter screen (204), a setpoint pressure reducing valve (205), and a high-pressure filter (206). The clutch C1 (201) is connected to the proportional electromagnetic pressure regulating valve (203) through an oil circuit. The proportional electromagnetic pressure regulating valve (203) is connected to the setpoint pressure reducing valve (205) through an oil circuit. The setpoint pressure reducing valve (205) is connected to the high-pressure filter (206) through an oil circuit. The oil supply subsystem (3) includes an oil pump group, a suction filter (303) and an oil tank (304). The oil cooler (101) and the high-pressure filter (206) are connected to the oil pump group through an oil circuit. The oil pump group is connected to the suction filter (303), and the suction filter (303) is connected to the oil tank (304). The clutch control system (2) further includes an accumulator (202), which is installed in the oil line between the clutch C1 (201) and the proportional electromagnetic pressure regulating valve (203); The clutch control system (2) also includes a pressure sensor (208), which is installed in the oil line between the clutch C1 (201) and the proportional electromagnetic pressure regulating valve (203); A temperature sensor (305) is installed inside the oil tank (304); The cooling and lubrication throttling holes (102) are provided in four parts, which are respectively connected to the LUB oil passage (103), C1 oil passage (104), EM1 oil passage (105) and EM2 oil passage (106) through oil passages; The oil pump assembly includes a first electronic pump (301) and a second electronic pump (302). The first electronic pump (301) is connected to the oil cooler (101) via an oil circuit, and the second electronic pump (302) is connected to the high-pressure filter (206) via an oil circuit. Alternatively, the oil pump assembly includes a first mechanical pump (306) and a third electronic pump (307). The first mechanical pump (306) is connected to the oil cooler (101) via an oil circuit, and the third electronic pump (307) is connected to the high-pressure filter (206) via an oil circuit. Two suction filters (303) are provided, which are respectively connected to the first mechanical pump (306) and the third electronic pump (307).

2. The hydraulic system for a hybrid power transmission according to claim 1, characterized in that, A pressure relief valve (308) is connected in parallel to the oil circuit of the first mechanical pump (306).

3. The hydraulic system for a hybrid power transmission according to claim 1, characterized in that, The high-pressure filter (206) is connected to a safety valve (207) at its end.

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