Variable displacement oil pump and control system
By incorporating a valve chamber and solenoid valve control system into the variable displacement oil pump, the problem of insufficient pressure regulation capability of existing oil pumps is solved, achieving more flexible pressure regulation and fuel-saving effects, and making it suitable for a wide range of vehicle models.
Patent Information
- Application Number
- CN202511275959.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-08
- Publication Date
- 2025-11-18
AI Technical Summary
Existing variable displacement oil pumps struggle to balance pressure regulation capability and cost, limiting their application in low- to mid-range and high-end vehicles, and also suffer from lag in response and limited pressure regulation.
A variable displacement oil pump and control system were designed. By setting a valve chamber on the side wall of the pump body cavity, installing a valve spring and a valve core, and using a solenoid valve and ECU to control the opening and closing of the second oil circuit and the amount of oil leakage, second-order or multi-order pressure regulation can be achieved, and the preload of the variable spring and the eccentricity of the rotor assembly can be adjusted.
It enables two-stage or multi-stage pressure regulation of the engine lubrication system, improving fuel efficiency and response speed, making it suitable for more vehicle models and reducing costs.
Smart Images
Figure CN120968808A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the lubrication system of an automobile engine, and more specifically to a variable displacement oil pump and its control system. Background Technology
[0002] Engine lubrication systems currently rely primarily on fixed displacement gear pumps and rotary pumps. However, with increasing emphasis on fuel economy and the application of new engine technologies, higher demands are being placed on oil pumps used in lubrication systems. Variable displacement vane pumps are becoming increasingly widely used in engines. Currently, the types of variable displacement vane pumps that are being mass-produced include single-stage variable displacement vane pumps with pressure feedback, two-stage pressure feedback variable displacement vane pumps with solenoid valve switching, and variable displacement vane pumps employing MAP (Magnetic Mapping) strategies for global control.
[0003] Single-stage variable displacement vane pumps have a simple structure and low cost, but high operating energy consumption, and are generally only used in low- to mid-range vehicles, with limited fuel-saving effects. Second-stage variable displacement vane pumps have low operating energy consumption, but a complex structure, generally controlled by a pilot valve and a switching solenoid valve. Although the fuel-saving effect is significantly improved compared to single-stage variable displacement pumps, the cost is high, and there are problems such as not being able to cover the entire range to achieve maximum fuel-saving effect through ECU calibration, response lag, and limited pressure adjustment. They are generally only used in mid- to high-end passenger vehicles. Variable oil pumps using MAP strategy for full-range control are basically the same as second-stage pressure feedback variable oil pumps using solenoid valve switching under typical engine speeds and typical loads, but the cost is higher, limiting their application. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a variable displacement oil pump with greater pressure regulation capability and a control system based on the oil pump, which can realize second-order or multi-order pressure regulation.
[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a variable displacement oil pump, comprising a pump body, a pump cover, a variable displacement slider, and a variable displacement spring. The pump body is provided with a cavity for accommodating the variable displacement slider and the variable displacement spring. A pressure feedback chamber is formed between the variable displacement slider and the side wall of the pump body cavity through a partial seal. A valve chamber is provided on the side wall of the pump body cavity. A valve spring and a valve core are installed in the valve chamber. The valve chamber is connected to the oil outlet chamber of the oil pump through an oil passage. One end of the variable displacement spring abuts against the valve core, and the other end abuts against the variable displacement slider.
[0006] In the above technical solution, a valve chamber is provided on the side wall of the pump body cavity. A valve spring and a valve core are installed in the valve chamber. The valve chamber is connected to the oil outlet chamber of the oil pump through an oil passage. In this way, pressurized oil can be introduced into the valve chamber. The pressurized oil and the valve spring together push the valve core to move upward, compressing the variable spring and thus increasing the preload of the variable spring.
[0007] In one embodiment, the valve core has a "Ji" - shaped structure with one end closed and the other end having a flanging. The valve cavity is adapted to the structure of the valve core, and the valve core can axially move within the valve cavity.
[0008] The present invention also provides a control system based on a variable - displacement oil pump, which includes an oil pump, a main oil passage, an oil pan, a solenoid valve, and an ECU. The oil pump includes a pump body, a pump cover, a variable slider, and a variable spring. A cavity is provided on the pump body for accommodating the variable slider and the variable spring. A rotor cavity is provided in the middle of the variable slider for accommodating a rotor assembly. A pressure feedback cavity is formed by local sealing between the variable slider and the side wall of the pump body cavity; A valve cavity is provided on the side wall of the pump body cavity, and a valve spring and a valve core are installed in the valve cavity. The valve cavity communicates with the oil outlet cavity of the oil pump through a first oil passage and communicates with the oil pan through a second oil passage. The solenoid valve is arranged on the second oil passage for controlling the on - off and oil discharge amount of the second oil passage, and the solenoid valve is controlled by the ECU; One end of the variable spring abuts against the valve core, and the other end abuts against the variable slider.
[0009] In one embodiment, the valve core has a "Ji" - shaped structure with one end closed and the other end having a flanging. The valve cavity is adapted to the structure of the valve core, and the valve core can axially move within the valve cavity.
[0010] In one embodiment, the solenoid valve is a two - position two - way proportional solenoid valve.
[0011] In one embodiment, the pressure feedback cavity communicates with the main oil passage through an oil passage.
[0012] The working principle of the above - mentioned control system is as follows: Since a valve cavity is provided on the side wall of the pump body cavity, a valve spring and a valve core are installed in the valve cavity, and the valve cavity communicates with the oil outlet cavity of the oil pump through a first oil passage, pressure oil can be introduced into the valve cavity. The pressure oil and the valve spring jointly push the valve core upward to compress the variable spring, thereby increasing the pre - compression force of the variable spring; Since the valve cavity also communicates with the oil pan through a second oil passage, the solenoid valve is arranged on the second oil passage for controlling the on - off of the second oil passage, and the solenoid valve is controlled by the ECU. Thus, the ECU can adjust the amount of pressure oil in the valve cavity, making the pre - compression force of the variable spring adjustable. As the pre - compression force of the variable spring changes, the torque of the oil in the pressure feedback cavity acting on the slider also changes. In this way, by giving different PWM duty - cycle signals to the solenoid valve by the ECU and performing MAP calibration, the oil pressure in the valve cavity changes, and the compression stroke of the variable spring is also different. Furthermore, together with the pressure oil in the pressure feedback cavity, the eccentricity of the rotor assembly and the variable slider is adjusted, and the displacement of the oil pump continuously changes. Thus, the oil flowing out to the engine lubrication system is also different, and the pressure of the engine main oil passage shows second - order pressure regulation or multi - order pressure regulation. Description of the Drawings
[0013] Figure 1 This is a schematic diagram of the overall structure of the solenoid valve in the de-energized state in the embodiments of the present invention;
[0014] Figure 2 This is a schematic diagram of the overall structure of the solenoid valve in the energized state in the embodiments of the present invention;
[0015] The reference numerals are as follows:
[0016] 1. Pump body; 2. Rotating pin; 3. Variable slider; 4. Variable spring; 5. Rotor; 6. Vane; 7. Pressure feedback chamber; 8. Valve chamber; 9. Valve spring; 10. Valve core; 11. Main oil passage; 12. Oil sump; 13. Solenoid valve. Detailed implementation manners
[0017] For the convenience of those skilled in the art to understand, the present invention will be further described below in conjunction with embodiments and the accompanying drawings. The content mentioned in the implementation manners does not limit the present invention.
[0018] It should be noted in advance that in the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.
[0019] Embodiment 1
[0020] As Figure 1 、 2 shown, a variable displacement oil pump includes a pump body 1, a pump cover, a rotating pin 2, a variable slider 3 and a variable spring 4. A cavity is provided on the pump body 1 to accommodate the variable slider 3 and the variable spring 4. A rotor cavity is provided in the middle of the variable slider 3 to accommodate the rotor 5 and the vane 6. A pressure feedback chamber 7 is formed between the variable slider 3 and the side wall of the cavity of the pump body 1 through local sealing. The variable slider 3 can swing left and right around the rotating pin 2; a valve chamber 8 is provided on the side wall of the cavity of the pump body 1. A valve spring 9 and a valve core 10 are installed in the valve chamber 8. The valve chamber 8 is communicated with the oil outlet chamber of the oil pump through an oil passage; one end of the variable spring 4 abuts against the valve core 10, and the other end abuts against the pressing block of the variable slider 3. In this embodiment, the valve core 10 has a "J" - shaped structure with one end closed and the other end having a flanging. The structure of the valve chamber 8 is adapted to the valve core 10, and the valve core 10 can axially move in the valve chamber 8.
[0021] Since there is a valve cavity 8 provided on the side wall of the cavity of the pump body 1, a valve spring 9 and a valve core 10 are installed in the valve cavity 8, and the valve cavity 8 is communicated with the oil outlet cavity of the oil pump through an oil passage, so that pressure oil can be introduced into the valve cavity 8. The pressure oil and the valve spring 9 jointly push the valve core 10 to move upward, compress the variable spring 4, and thus increase the pre-tightening force of the variable spring 4.
[0022] Embodiment 2
[0023] As Figure 1 、 2 shown, a control system based on a variable-displacement oil pump includes a vane pump, a main oil passage 11, an oil pan 12, a solenoid valve 13 and an ECU. The vane pump includes a pump body 1, a pump cover, a rotating pin 2, a variable slider 3 and a variable spring 4. The pump body 1 is provided with a cavity for accommodating the variable slider 3 and the variable spring 4. A rotor cavity is provided in the middle of the variable slider 3 for accommodating a rotor 5 and vanes 6. A pressure feedback cavity 7 is formed between the variable slider 3 and the side wall of the cavity of the pump body 1 through local sealing. The pressure feedback cavity 7 is communicated with the main oil passage 11 through an oil passage. The pressure feedback cavity 7 and the variable spring 4 oppose each other, enabling the variable slider 3 to swing left and right around the rotating pin 2. There is a valve cavity 8 provided on the side wall of the cavity of the pump body 1. A valve spring 9 and a valve core 10 are installed in the valve cavity 8. The valve cavity 8 is communicated with the oil outlet cavity of the oil pump through a first oil passage and is communicated with the oil pan 12 through a second oil passage. The solenoid valve 13 is arranged on the second oil passage for controlling the on / off and oil discharge amount of the second oil passage. The solenoid valve 13 is controlled by the ECU. One end of the variable spring 4 abuts against the valve core 10, and the other end abuts against the pressing block of the variable slider 3.
[0024] In this embodiment, the valve core 10 has a "C" - shaped structure with one end closed and the other end having a flanging. The valve cavity 8 is adapted to the structure of the valve core 10, and the valve core 10 can axially move in the valve cavity 8. The solenoid valve 13 is a two-position two-way proportional solenoid valve, including a P port communicated with the valve cavity 8 and a T port communicated with the oil pan 12.
[0025] The working principle of the above control system is as follows: Since there is a valve cavity 8 provided on the side wall of the cavity of the pump body 1, a valve spring 9 and a valve core 10 are installed in the valve cavity 8, and the valve cavity 8 is communicated with the oil outlet cavity of the oil pump through a first oil passage, so that pressure oil can be introduced into the valve cavity 8. The pressure oil and the valve spring 9 jointly push the valve core 10 to move upward, compress the variable spring 4, and thus increase the pre-tightening force of the variable spring 4. Since the valve cavity 8 is also communicated with the oil pan 12 through a second oil passage, the solenoid valve 13 is arranged on the second oil passage for controlling the on / off and oil discharge amount of the second oil passage, and the solenoid valve 13 is controlled by the ECU. Thus, the amount of pressure oil in the valve cavity 8 can be adjusted through the ECU, so that the pre-tightening force of the variable spring 4 becomes adjustable. As the pre-tightening force of the variable spring 4 changes, the torque of the oil in the pressure feedback cavity 7 acting on the slider will also change accordingly.
[0026] When the two-position two-way proportional solenoid valve 13 is de-energized, the passages of port P and port T are closed, and the valve chamber 8 is filled with pressurized oil. At this time, the pressure of the pressurized oil on the valve core 10 is at its maximum, and the valve core 10 maximizes the compression of the variable spring 4. The torque of the variable spring 4 on the slider is also at its maximum. The pressurized oil in the pressure feedback chamber 7 cannot overcome the pre-compression force of the variable spring 4 and push the slider to swing around the rotating pin 2. At this time, the oil pump works at its maximum displacement state to output flow.
[0027] When the two-position two-way proportional solenoid valve 13 is energized, the ECU sends a certain PWM duty cycle signal to the solenoid valve 13, opening the P and T ports. The oil in the valve chamber 8 flows back to the oil pan 12 through the second oil circuit, and the pressure oil in the valve chamber 8 decreases accordingly. Since the force of the variable spring 4 (the force generated by spring compression) = the force of the valve spring 9 acting on the valve core 10 + the force of the pressure oil in the valve chamber 8 acting on the slide valve, as the pressure oil in the valve chamber 8 decreases, the above force balance is temporarily broken. The valve core 10 moves downward, the compression of the variable spring 4 decreases, and a new balance is established. For the slider, the torque of the pressure oil in the pressure feedback chamber 7 acting on the slider is equal to the torque of the variable spring 4 acting on the slider. Therefore, the decrease in the compression of the variable spring 4 will affect the eccentricity of the rotor 5 assembly and the variable slider 3, thus changing the flow output. At this time, the variable displacement oil pump enters a partial displacement output state.
[0028] In this way, by giving the solenoid valve 13 different PWM duty cycle signals through the ECU and performing MAP calibration, the oil pressure in the valve chamber 8 changes, and the compression stroke of the variable spring 4 is also different. In turn, together with the pressure oil in the pressure feedback chamber 7, the eccentricity of the rotor 5 and the variable slider 3 is adjusted, so that the displacement of the oil pump changes continuously. Thus, the oil output flowing to the engine lubrication system is also different, and the pressure of the engine main oil passage 11 also exhibits second-order or multi-order pressure regulation.
[0029] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present technical solution are within the protection scope of the present invention.
[0030] To facilitate understanding by those skilled in the art of the improvements of this invention over the prior art, some of the accompanying drawings and descriptions have been simplified, and for clarity, some other elements have been omitted from this application. Those skilled in the art should realize that these omitted elements may also constitute the content of this invention.
Claims
1. A variable displacement oil pump, comprising a pump body (1), a pump cover, a variable displacement slider (3), and a variable displacement spring (4), wherein the pump body (1) has a cavity for accommodating the variable displacement slider (3) and the variable displacement spring (4), the variable displacement slider (3) has a rotor cavity in the middle for accommodating a rotor (5) assembly, and a pressure feedback cavity (7) is formed between the variable displacement slider (3) and the side wall of the cavity of the pump body (1) through a partial seal, characterized in that: A valve cavity (8) is provided on the side wall of the cavity of the pump body (1). A valve spring (9) and a valve core (10) are installed in the valve cavity (8). The valve cavity (8) communicates with the oil outlet cavity of the oil pump through an oil passage; one end of the variable spring (4) abuts against the valve core (10), and the other end abuts against the variable slider (3).
2. The variable displacement oil pump according to claim 1, characterized in that: The valve core (10) has a "U" - shaped structure with one end closed and the other end having a flange. The valve cavity (8) is adapted to the structure of the valve core (10), and the valve core (10) can axially move within the valve cavity (8).
3. A control system based on a variable displacement oil pump, comprising an oil pump, a main oil passage (11), an oil pan (12), a solenoid valve (13), and an ECU, characterized in that: The oil pump includes a pump body (1), a pump cover, a variable slider (3) and a variable spring (4). A cavity is provided on the pump body (1) for accommodating the variable slider (3) and the variable spring (4). A rotor cavity is provided in the middle of the variable slider (3) for accommodating the rotor assembly. A pressure feedback cavity (7) is formed by local sealing between the variable slider (3) and the side wall of the cavity of the pump body (1); A valve cavity (8) is provided on the side wall of the cavity of the pump body (1). A valve spring (9) and a valve core (10) are installed in the valve cavity (8). The valve cavity (8) communicates with the oil outlet cavity of the oil pump through a first oil passage and communicates with the oil pan (12) through a second oil passage. The solenoid valve (13) is arranged on the second oil passage for controlling the on - off of the second oil passage and the oil discharge amount. The solenoid valve (13) is controlled by an ECU; One end of the variable spring (4) abuts against the valve core (10), and the other end abuts against the variable slider (3).
4. The control system based on a variable displacement oil pump according to claim 3, characterized in that: The valve core (10) has a "U" - shaped structure with one end closed and the other end having a flange. The valve cavity (8) is adapted to the structure of the valve core (10), and the valve core (10) can axially move within the valve cavity (8).
5. The control system based on a variable displacement oil pump according to claim 3 or 4, characterized in that: The solenoid valve (13) is a two - position two - way proportional solenoid valve.
6. The control system based on a variable displacement oil pump according to claim 3 or 4, characterized in that: The pressure feedback cavity (7) communicates with the main oil passage (11) through an oil passage.