Open type plunger variable pump
By integrating flow control valves and pressure valves into the variable pump, the linkage control of flow and pressure is realized, solving the adjustment problem of variable pump under complex operating conditions and improving the system's response speed and stability.
Patent Information
- Application Number
- CN202520538487.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-03-26
AI Technical Summary
Existing variable pumps have limitations in flow and pressure control, especially in complex operating conditions where precise adjustment is difficult, resulting in high system energy consumption and slow response speed.
An open-type variable piston pump with integrated flow control valve and pressure valve achieves linkage control of flow and pressure through the intermediate oil passage. The variable piston pushes the swashplate to change the tilt and adjust the oil discharge. Combined with the manually adjustable handle, precise control is achieved.
It improves the system's response speed and stability, adapts to different working conditions, and enhances the accuracy of flow and pressure regulation and ease of operation.
Smart Images
Figure CN223952724U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to hydraulic technology field, concretely relates to an open type plunger variable pump. BACKGROUND
[0002] In the current engineering machinery market, axial piston pumps are widely used in mobile engineering machinery such as excavators, loaders, tractors and bulldozers due to their high power-to-weight ratio and flexible flow and power control characteristics. As the core power component, the performance of the variable pump directly affects the working efficiency and stability of the entire system. The traditional variable pump mainly controls the displacement of the oil by adjusting the inclination angle of the swash plate, thereby achieving flow regulation. However, the existing variable pump has certain limitations in flow and pressure control, especially under complex working conditions, it is difficult to achieve accurate flow and pressure regulation, resulting in high system energy consumption and slow response speed.
[0003] Currently, the variable pumps commonly seen in the market mostly use a single control valve to achieve flow or pressure regulation. Although this design is simple in structure, it often fails to meet the needs of multiple working conditions in actual applications. For example, in cases where the load changes significantly, a single control valve cannot simultaneously ensure the stability of the flow and the precise control of the pressure, leading to a decline in system performance, which needs to be improved. SUMMARY
[0004] The utility model aims at the above -mentioned problem provides a kind of open type plunger variable pump that can automatically regulate and control oil flow and pressure.
[0005] To achieve the above purpose, the utility model discloses an open type plunger variable pump, comprising a pump body, an oil inlet and an oil outlet are provided on the pump body, a swash plate for controlling the displacement of oil is installed in the pump body, a variable cavity is provided in the pump body, a variable piston for pushing the swash plate to change the inclination of the swash plate is installed in the variable cavity, and the structural characteristics are as follows: a control valve body is installed on the pump body, the control valve body comprises a flow control valve and a pressure valve, a flow valve cavity is provided in the flow control valve, a pressure valve cavity is provided in the pressure valve, an intermediate oil passage connecting the flow valve cavity and the pressure valve cavity is provided in the control valve body, a pressure oil passage connecting the pressure valve cavity and the variable cavity is provided in the control valve body, a flow oil passage connecting the flow valve cavity and the pressure valve cavity is provided in the control valve body, a return oil passage is provided on the pump body, one end of the return oil passage is connected to the flow oil passage, the other end of the return oil passage is connected to the oil outlet, a load oil port connecting the load pipeline is provided on the control valve body, the load oil port is in communication with the flow valve cavity, a flow valve core for connecting or cutting off the intermediate oil passage and the flow oil passage is movably installed in the flow valve cavity, and a pressure valve core for connecting or cutting off the intermediate oil passage and the pressure oil passage is movably installed in the pressure valve cavity.
[0006] The flow control valve and the pressure valve can realize linkage control of flow and pressure through the intermediate oil passage, the variable piston is displaced, the swash plate is pushed by the variable piston, the inclination of the swash plate is changed, the oil displacement of the variable pump is adjusted, the flow control of the variable pump is realized, the response speed and stability of the system are improved, and different working condition requirements can be met.
[0007] The flow valve cavity movably installs a flow plug, the flow valve cavity installs a flow spring, and the flow spring is located between the flow valve core and the flow plug. The flow spring pushes the flow valve core, so that the flow valve is in a normal state, the intermediate oil passage and the flow oil passage are in a cut-off state, when the oil from the load oil port enters the flow valve cavity, the oil pushes the flow valve core and overcomes the resistance of the flow spring, so that the intermediate oil passage and the flow oil passage are in a communication state.
[0008] A support sleeve is installed on the flow control valve, a first handle is installed on the support sleeve, the first handle comprises a rotating cylinder, the rotating cylinder is sleeved on the end of the support sleeve, a top rod is arranged at the bottom of the rotating cylinder, the top rod penetrates through the support sleeve and extends into the flow valve cavity, one end of the top rod extending into the flow valve cavity abuts against the flow plug, and threads capable of cooperating with each other are arranged on the outer wall of the top rod and the inner wall of the support sleeve. When the first handle is rotated, the top rod and the support sleeve are screwed, at the same time, the top rod pushes or pulls the flow plug, so that the compression degree of the flow spring is changed, the greater the compression degree of the flow spring, the smaller the displacement of the variable pump ultimately fed back, and vice versa.
[0009] A ball bowl is arranged on one side of the flow plug close to the top rod, a ball head is arranged on the top rod, and the ball head is installed in the ball bowl and ball-hinged with the ball bowl. The ball-hinged cooperation of the ball head and the ball bowl reduces friction and improves the movement flexibility and service life of the top rod.
[0010] A scale is arranged on the support sleeve and used for displaying the rotating distance of the rotating cylinder, so that an operator can intuitively know the compression degree of the flow spring and the accuracy of flow adjustment of the variable pump is improved.
[0011] A pressure plug is movably installed in the pressure valve, a pressure spring is installed in the pressure valve, the pressure spring is located between the pressure valve core and the pressure plug, a second handle for controlling the compression degree of the pressure spring is installed on the pressure valve, and the installation structure of the second handle is the same as that of the first handle.
[0012] A second handle for controlling the compression degree of the pressure spring is installed on the pressure valve, a support sleeve is installed on the pressure valve, the second handle is installed on the support sleeve, the second handle comprises a rotating cylinder, the rotating cylinder is sleeved on the end of the support sleeve, a top rod is arranged at the bottom of the rotating cylinder, the top rod penetrates through the support sleeve and extends into the pressure valve cavity, one end of the top rod extending into the pressure valve cavity abuts against the pressure plug, and threads capable of cooperating with each other are arranged on the outer wall of the top rod and the inner wall of the support sleeve. The first handle and the second handle have the same structure principle, and excessive description is not given here
[0013] The pump body is provided with a top spring for tilting the swash plate towards the variable piston, which ensures the automatic reset of the swash plate without external force, thereby improving the safety and stability of the system.
[0014] The pump body is provided with a cylinder body, and the pump body is provided with a main shaft for driving the cylinder body to rotate, and the cylinder body is provided with a plunger abutting against the swash plate.
[0015] The pump body is provided with an oil injection flow channel, one end of which is communicated with the rodless cavity of the variable cavity, and the other end is communicated with the pressure oil channel.
[0016] In summary, the beneficial effects of the utility model lie in that the flow control valve and the pressure valve are integrated on the pump body, realizing the double regulation of flow and pressure. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 Figure 6 is a structural schematic view of the variable pump when the swash plate is at the maximum inclination angle;
[0018] Figure 2 Figure 7 is a structural schematic view of the variable pump when the swash plate is at the minimum inclination angle;
[0019] Figure 3 Figure 8 is a bottom view of the control valve body;
[0020] Figure 4 Figure 9 is a sectional view along the A-A line of the control valve body; Figure 3
[0021] Figure 5 Figure 10 is an external structural schematic view of the flow control valve and the pressure valve;
[0022] Figure 6 Figure 11 is a structural schematic view of the oil inlet and the oil outlet.
[0023] In the figure: pump body 1, plunger 2, swash plate 3, top spring 4, main shaft 5, flow control valve 6, pressure valve 7, support sleeve 8, oil return oil way 9, oil injection flow channel 10, first rotating handle 11, second rotating handle 12, scale 13, flow oil way 14, pressure oil way 15, flow valve core 16, intermediate oil way 17, pressure valve core 18, pressure valve cavity 19, flow valve cavity 20, flow spring 21, pressure spring 22, flow top plug 23, pressure top plug 24, top rod 25, rotating drum 26, thread 27, ball bowl 28, ball head 29, cylinder body 30, top spring 31, oil inlet 32, oil outlet 33, variable cavity 34, variable piston 35, load oil port 36. DETAILED DESCRIPTION
[0024] The specific embodiments of the present application will be further described in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application, but not to limit the scope of the present application.
[0025] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0026] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.
[0027] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0028] The following is a description of the preferred embodiments of the present application in conjunction with the accompanying drawings.
[0029] An open type piston variable pump comprises a pump body 1, an oil inlet 32 and an oil outlet 33 arranged on the pump body 1, a swash plate 3 arranged in the pump body 1 for controlling the oil displacement, a variable chamber 34 arranged in the pump body 1, a variable piston 35 arranged in the variable chamber 34 for pushing the swash plate 3 to change the inclination of the swash plate 3, a control valve body arranged on the pump body 1, the control valve body comprising a flow control valve 6 and a pressure valve 7, a flow valve chamber 20 arranged in the flow control valve 6, a pressure valve chamber 19 arranged in the pressure valve 7, an intermediate oil passage 17 connecting the flow valve chamber 20 and the pressure valve chamber 19 arranged in the control valve body, a pressure oil passage 15 connecting the pressure valve chamber 19 and the variable chamber 34 arranged in the control valve body, a flow oil passage 14 connecting the flow valve chamber 20 and the pressure valve chamber 19 arranged in the control valve body, an oil return passage 9 arranged on the pump body 1, one end of the oil return passage 9 being connected with the flow oil passage 14 and the other end of the oil return passage 9 being connected with the oil outlet 33, a load oil port 36 arranged on the control valve body for connecting a load pipeline, the load oil port 36 being communicated with the flow valve chamber 20, a flow valve core 16 movably arranged in the flow valve chamber 20 for connecting or cutting off the intermediate oil passage 17 and the flow oil passage 14, and a pressure valve core 18 movably arranged in the pressure valve chamber 19 for connecting or cutting off the intermediate oil passage 17 and the pressure oil passage 15.
[0030] Refer to the drawings Figure 4, the flow control valve 6 and the pressure valve 7 can realize the linkage control of the flow and the pressure through the intermediate oil passage 17, so that the variable piston 35 is displaced, and then the variable piston 35 pushes the swash plate 3 to change the inclination of the swash plate 3, thereby adjusting the oil displacement of the variable pump, realizing the flow control of the variable pump, improving the response speed and stability of the system, and adapting to different working conditions. The flow plug 23 is movably installed in the flow valve cavity 20, the flow spring 21 is installed in the flow valve cavity 20, and the flow spring 21 is located between the flow valve core 16 and the flow plug 23. The flow spring 21 pushes the flow valve core 16, so that the flow valve is in a normal state, the intermediate oil passage 17 and the flow oil passage 14 are in a cut-off state, when the oil from the load oil port 36 enters the flow valve cavity 20, the oil pushes the flow valve core 16, and overcomes the resistance of the flow spring 21, so that the intermediate oil passage 17 and the flow oil passage 14 are in a communication state. The support sleeve 8 is installed on the flow control valve 6, the first handle 11 is installed on the support sleeve 8, the first handle 11 includes the rotating barrel 26, the rotating barrel 26 is sleeved on the end of the support sleeve 8, the bottom of the rotating barrel 26 is provided with the top rod 25, the top rod 25 extends into the flow valve cavity 20 through the support sleeve 8, one end of the top rod 25 extending into the flow valve cavity 20 abuts against the flow plug 23, and threads 27 capable of cooperating with each other are arranged on the outer wall of the top rod 25 and the inner wall of the support sleeve 8. When the first handle 11 is rotated, the top rod 25 and the support sleeve 8 are screwed, at the same time, the top rod 25 pushes or pulls the flow plug 23, so that the compression degree of the flow spring 21 is changed, the greater the compression degree of the flow spring 21, the smaller the final displacement feedback to the variable pump, and vice versa. The side of the flow plug 23 close to the top rod 25 is provided with the ball bowl 28, the top rod 25 is provided with the ball head 29, the ball head 29 is installed in the ball bowl 28 and the two are ball-hinged. The ball-hinged cooperation of the ball head 29 and the ball bowl 28 reduces friction and improves the movement flexibility and service life of the top rod 25. The support sleeve 8 is provided with the scale 13 for displaying the rotation distance of the rotating barrel 26, so that the operator can intuitively understand the compression degree of the flow spring 21, and the accuracy of the flow adjustment of the variable pump is improved.
[0031] Referring to the drawings Figure 4A pressure plug 24 is movably installed in the pressure valve 7. A pressure spring 22 is installed in the pressure valve 7. The pressure spring 22 is located between the pressure valve core 18 and the pressure plug 24. A second handle 12 for controlling the compression degree of the pressure spring 22 is installed on the pressure valve 7. The second handle 12 has the same installation structure as the first handle 11. The valve core structure of the pressure valve 7 and the adjustment structure of the second handle 12 for the pressure spring 22 are the same as those of the flow regulating valve. The pressure valve 7 is equipped with a second handle 12 for controlling the compression degree of the pressure spring 22. The pressure valve 7 is equipped with a support sleeve 8, and the support sleeve 8 is equipped with the second handle 12. The second handle 12 includes a rotating cylinder 26, which is sleeved on the end of the support sleeve 8. The bottom of the rotating cylinder 26 is provided with a push rod 25, which passes through the support sleeve 8 and extends into the pressure valve cavity 19. One end of the push rod 25 extending into the pressure valve cavity 19 abuts against the pressure plug 24. The outer wall of the push rod 25 and the inner wall of the support sleeve 8 are provided with threads 27 that can cooperate with each other.
[0032] See attached document Figure 1 Appendix Figure 2 The pump body 1 is equipped with a top spring that pushes the swashplate 3 towards the variable piston 35. The top spring ensures that the swashplate 3 can automatically return to its original position when no external force is applied, improving the safety and stability of the system. A cylinder 30 is rotatably mounted in the pump body 1, and a main shaft 5 is installed in the pump body 1 to drive the cylinder 30 to rotate. A plunger 2 is mounted on the cylinder 30 and rests against the swashplate 3. The cooperation between the plunger 2 and the swashplate 3 ensures stable oil delivery and improves the pump's working efficiency. The pump body 1 is provided with an oil injection channel 10. One end of the oil injection channel 10 is connected to the rodless chamber of the variable pump 34, and the other end is connected to the pressure oil passage 15. After the oil from the pressure oil passage 15 enters the rodless chamber of the variable pump 34, it pushes the variable piston 35, which in turn pushes the swashplate 3, ultimately changing the displacement of the variable pump.
[0033] When the equipment is working, the main shaft 5 drives the cylinder 30 to rotate. The plunger 2 on the cylinder 30 presses against the swashplate 3. When the cylinder 30 rotates, the plunger 2 in the cylinder 30 plunger 2 hole gradually moves upward from the lowest point (bottom dead center) at the bottom of the hole to the highest point (top dead center). At this time, the sealing working volume of the cylinder hole at the bottom of the plunger 2 increases, forming a negative pressure, and hydraulic oil is drawn in from the oil inlet 32 to complete the oil suction process.
[0034] Due to the constraint of swashplate 3 and the effect of variable piston 35 changing the tilt angle of swashplate 3, plunger 2 gradually moves downward, from the highest point (top dead center) to the lowest point (bottom dead center). The cylinder bore volume decreases, the oil is compressed and discharged through the pressure window of the distributor plate, and finally discharged from the outlet 33, thus completing the oil compression process. For each revolution of cylinder 30, plunger 2 completes one oil suction and oil compression process, and so on, continuously providing hydraulic energy to the working system.
[0035] The flow control valve 6 is connected with the load sensitive valve through a load line, and the load sensitive valve senses the highest load pressure, when the flow of the variable pump is greater than the set value, the oil at the oil outlet 33 enters the flow valve cavity 20 through the oil return oil channel 9 and the flow oil channel 14, when the oil pressure at the oil outlet 33 is greater than the oil pressure at the load line plus the resistance of the flow spring 21, the flow valve core 16 moves to the right, the annular plug on the flow valve core 16 is separated from the middle oil channel 17, the middle oil channel 17 and the flow oil channel 14 are communicated, the oil at the oil outlet 33 enters the pressure valve cavity 19 through the middle oil channel 17, and then enters the rodless cavity of the variable valve cavity through the pressure flow channel, so as to drive the variable piston 35 to move left, the variable piston 35 drives the swash plate 3 to reduce the inclination angle, at this time, the displacement of the variable pump is reduced.
[0036] When the pressure at the oil outlet 33 of the variable pump is higher than the set pressure of the pressure valve 7, the pressure valve core 18 moves to the right, the oil at the oil outlet 33 enters the flow valve cavity 20 and the pressure valve cavity 19 through the oil return oil channel 9 and the flow oil channel 14, at this time, the oil fails to drive the flow valve core 16, but the oil pressure is greater than the elastic force of the pressure spring 22, and the pressure valve core 18 can be driven to move right, the flow oil channel 14 and the pressure flow channel are communicated, the oil enters the rodless cavity of the variable valve cavity through the pressure flow channel, and drives the variable piston 35, so as to change the displacement of the variable pump.
[0037] The above only describes the preferred embodiments of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and substitutions can be made, and these improvements and substitutions should also be considered as the protection scope of the present application.
Claims
1. An open-type variable displacement piston pump, comprising a pump body (1), an oil inlet (32) and an oil outlet (33) provided on the pump body (1), a swashplate (3) for controlling the oil discharge rate installed in the pump body (1), a variable displacement chamber (34) provided in the pump body (1), and a variable displacement piston (35) for pushing the swashplate (3) to change the inclination of the swashplate (3) installed in the variable displacement chamber (34), characterized in that, The pump body (1) is equipped with a control valve body, which includes a flow control valve (6) and a pressure valve (7). The flow control valve (6) has a flow valve chamber (20), and the pressure valve (7) has a pressure valve chamber (19). The control valve body has an intermediate oil passage (17) connecting the flow valve chamber (20) and the pressure valve chamber (19). The control valve body has a pressure oil passage (15) connecting the pressure valve chamber (19) and the variable chamber (34). The control valve body has a flow oil passage (14) connecting the flow valve chamber (20) and the pressure valve chamber (19). The pump body (1) is equipped with... There is a return oil passage (9), one end of which is connected to the flow oil passage (14), and the other end of which is connected to the oil outlet (33). The control valve body is provided with a load oil port (36) for connecting the load pipeline. The load oil port (36) is connected to the flow valve chamber (20). The flow valve chamber (20) is movably installed with a flow valve core (16) for connecting or cutting off the intermediate oil passage (17) and the flow oil passage (14). The pressure valve chamber (19) is movably installed with a pressure valve core (18) for connecting or cutting off the intermediate oil passage (17) and the pressure oil passage (15). A flow top plug (23) is movably installed in the flow valve chamber (20), and a flow spring (21) is installed in the flow valve chamber (20). The flow spring (21) is located between the flow valve core (16) and the flow top plug (23). A support sleeve (8) is installed on the flow control valve (6), and a first rotating handle (11) is installed on the support sleeve (8). The first rotating handle (11) includes a rotating cylinder (26). The rotating cylinder (26) is sleeved on the end of the support sleeve (8). A push rod (25) is provided at the bottom of the rotating cylinder (26). The push rod (25) passes through the support sleeve (8) and extends into the flow valve cavity (20). One end of the push rod (25) extending into the flow valve cavity (20) abuts against the flow top plug (23). The outer wall of the push rod (25) and the inner wall of the support sleeve (8) are provided with threads (27) that can cooperate with each other.
2. The open-type variable displacement piston pump as described in claim 1, characterized in that, The flow top plug (23) has a ball cup (28) on the side near the top rod (25), and a ball head (29) is provided on the top rod (25). The ball head (29) is installed in the ball cup (28) and the two are ball-jointed.
3. The open-type variable displacement piston pump as described in claim 2, characterized in that, The support sleeve (8) is provided with a scale (13) for displaying the advance distance of the rotating drum (26).
4. The open-type variable displacement piston pump as described in claim 1, characterized in that, A pressure plug (24) is movably installed in the pressure valve (7), and a pressure spring (22) is installed in the pressure valve (7). The pressure spring (22) is located between the pressure valve core (18) and the pressure plug (24).
5. The open-type variable displacement piston pump as described in claim 1, characterized in that, The pressure valve (7) is equipped with a second handle (12) for controlling the compression degree of the pressure spring (22). The pressure valve (7) is equipped with a support sleeve (8). The support sleeve (8) is equipped with a second handle (12). The second handle (12) includes a rotating cylinder (26). The rotating cylinder (26) is sleeved on the end of the support sleeve (8). The bottom of the rotating cylinder (26) is provided with a push rod (25). The push rod (25) passes through the support sleeve (8) and extends into the pressure valve cavity (19). One end of the push rod (25) extending into the pressure valve cavity (19) abuts against the pressure plug (24). The outer wall of the push rod (25) and the inner wall of the support sleeve (8) are provided with threads (27) that can cooperate with each other.
6. The open-type variable displacement piston pump as described in claim 1, characterized in that, The pump body (1) is equipped with a top spring (4) for pushing the swashplate (3) toward the variable piston (35).
7. The open-type variable displacement piston pump as described in claim 1, characterized in that, A cylinder (30) is rotatably mounted in the pump body (1), and a main shaft (5) for driving the cylinder (30) to rotate is installed in the pump body (1). A plunger (2) is mounted on the cylinder (30) and rests against the swashplate (3).
8. The open-type variable displacement piston pump as described in claim 1, characterized in that, The pump body (1) is provided with an oil injection channel (10), one end of which is connected to the rodless cavity of the variable cavity (34), and the other end is connected to the pressure oil channel (15).