Pressure-protected water medium swash plate axial piston pump

Abstract

The application belongs to the technical field of fluid transmission and control equipment, and relates to a water medium swash plate type axial plunger pump with pressure protection, which comprises a shell, one end of the shell is connected with an inlet-outlet water flange in a sealing mode, the outer end surface of the inlet-outlet water flange is fixedly connected with a front cover plate, and the other end of the shell is fixed with a rear end cover; a main shaft is rotatably arranged on the inlet-outlet water flange and the front cover plate, the shaft diameter of the main shaft extending into the shell is matched and connected with the inner hole of a cylinder body, a main spring is arranged in the inner hole of the cylinder body and corresponds to the end of the main shaft, a ball hinge is arranged on the end surface of the inner hole of the cylinder body, the main spring is pressed on the ball hinge, the ball hinge is matched and connected with a return plate, a plunger is arranged on the cylinder body and corresponds to the outer ring of the inner hole, and the return plate and the plunger press a sliding shoe on the first inclined surface of a swash plate. The plunger pump can reduce the output flow of the pump when the pressure is too high, and can protect each part of the pump body.

Description

Technical Field

[0001] This invention belongs to the technical field of fluid transmission and control equipment, and relates to a water medium swashplate axial piston pump with pressure protection. Background Technology

[0002] A green transmission technology that has re-emerged in the 20th century, using water (including seawater and freshwater) as the working medium, is currently a cutting-edge research direction in the field of fluid transmission and control internationally. Seawater hydraulic transmission technology, which directly uses seawater as the working medium, has become the development direction of power drive systems for underwater equipment internationally. It has been proven by years of practical application in developed Western countries to be the best power drive method and has become the inevitable choice for the power drive system of underwater equipment.

[0003] Hydraulic pumps are the core power components of hydraulic transmission systems. For many years, Western countries have listed them as high-tech projects with significant engineering application value, and have developed a series of mature hydraulic pump products. Currently, the products on the market are mainly of the axial piston type. In recent years, major universities in China, such as Huazhong University of Science and Technology and Zhejiang University, have also gradually carried out research on hydraulic transmission and control, and have gradually developed several prototype hydraulic axial piston pumps.

[0004] Currently, axial piston pumps for water media are mainly fixed displacement pumps. The system is typically equipped with a safety valve; when the system pressure is too high, the safety valve opens to overflow, thereby controlling the system pressure. However, this method has the following disadvantages:

[0005] 1) The pump continues to operate at full power while the safety valve is in operation;

[0006] 2) The power consumption is very high, and the system heats up quickly;

[0007] 3) Increases unnecessary wear on the pump;

[0008] 4) If the safety valve becomes stuck, it will cause damage to the water pump and other components. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides a pressure-protected swashplate axial piston pump for water media. This piston pump can reduce the pump's output flow rate when the pressure is too high, thus protecting the various components of the pump body.

[0010] According to the technical solution of the present invention: a water medium swash plate axial piston pump with pressure protection, characterized in that: it includes a housing, one axial end of the housing is sealed to an inlet and outlet flange, the outer end face of the inlet and outlet flange is fastened to a front cover plate, and the other axial end of the housing is fixed to a rear end cover.

[0011] The main shaft is rotatably mounted on the inlet and outlet flanges and the front cover plate. The shaft diameter of the main shaft extends into the housing and is connected to the inner hole of the cylinder body. A main spring is installed in the inner hole of the cylinder body corresponding to the end of the main shaft. A ball joint is installed on the end face of the inner hole of the cylinder body. The main spring is pressed against the ball joint. The ball joint is connected to the return plate. A plunger is installed on the outer ring of the cylinder body corresponding to the inner hole. The return plate and the plunger press the slipper against the first inclined surface of the swashplate. A rotating steel ball is installed between the second inclined surface of the swashplate and the contact surface of the rear end cover. The swashplate is also provided with a third inclined surface. The third inclined surface extends to the outer end of the second inclined surface and forms an obtuse angle with the second inclined surface.

[0012] A control valve assembly is installed on the inlet and outlet flanges. The control valve assembly includes a valve body, on which a high-pressure water port and a control water port are provided. The valve body is provided with a control mechanism to control the connection or disconnection of the high-pressure water port and the control water port. The control water port is connected to one end of a flow channel on the valve body, and the other end of the flow channel extends to a support position on the rear end cover. The support can move axially relative to the rear end cover, and a support spring is provided between the support and the rear end cover. The high-pressure water port is connected to the water pump outlet provided on the inlet and outlet flanges.

[0013] As a further improvement of the present invention, the control mechanism includes a nut connected to the axial hole of the valve housing, a plug also provided in the axial hole of the valve housing, a variable valve core between the plug and the nut, a spring seat and a spring provided in the inner hole of the nut, the spring and the spring seat being fastened together, the other end of the spring pressing against one axial end of the variable valve core, the other axial end of the variable valve core passing through the end through hole of the plug and pressing against a control steel ball provided on the outside of the plug, the steel ball being used to adjust the opening and closing of the control port, and there is a moving gap between the variable valve core and the axial end of the nut.

[0014] As a further improvement of the present invention, the core of the variable valve core is provided with a limiting flange, the core of the variable valve core corresponding to the limiting flange side extends into the nut, and the end of the core of the variable valve core corresponding to the limiting flange side is provided with an axial extension portion, the axial extension portion passing through the end through hole of the nut.

[0015] As a further improvement of the present invention, the inlet and outlet flanges are fixed to a distribution plate on one side of the shell, and the cylinder body is provided with a floating plate on one side of the distribution plate.

[0016] As a further improvement of the present invention, semi-circular ball sockets are respectively provided on the second inclined surface of the rear end cover and the swashplate, and rotating steel balls are provided in the ball sockets that cooperate with each other on the second inclined surface of the rear end cover and the swashplate.

[0017] The technical advantages of this invention are as follows: When the system pressure is too high during operation, the water pump first changes its swashplate angle to reduce the pump output flow, protecting all system components. Simultaneously, it works in conjunction with the system safety valve for double protection. Specifically, this is reflected in the following aspects: 1. A control valve assembly is installed in the pump body, which can control the opening of the high-pressure / low-pressure valves at the bottom of the support according to the pump outlet pressure; 2. Throttling orifices are installed inside the control valve assembly and at the bottom of the support to control the swashplate swing speed and avoid impacts during the swing of the variable-angle swashplate; 3. The bottom of the variable-angle swashplate is supported by two steel balls and a support, and it can swing along the axis of the two steel balls under the action of the support. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the present invention.

[0019] Figure 2 This is a schematic diagram of the pressure control valve assembly.

[0020] Figure 3 This is a schematic diagram of the swashplate.

[0021] Figure 4 This is the bottom view of the swashplate.

[0022] Figure 5 This is a side view of the swashplate.

[0023] Figure 6 This is a schematic diagram of the present invention. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0025] Figures 1-6 The components include: spindle 1, front cover plate 2, inlet and outlet flanges 3, high-pressure water port 3-1, control water port 3-2, housing 4, distribution plate 5, floating plate 6, cylinder block 7, plunger 8, slipper 9, return plate 10, ball joint 11, rear end cover 12, support spring 13, support 14, swashplate 15, first inclined plane 15-1, second inclined plane 15-2, third inclined plane 15-3, ball socket 15-4, swashplate variable axis 15-5, pressure control valve assembly 16, valve housing 17, control steel ball 18, screw plug 19, variable valve core 20, spring 21, spring seat 22, nut 23, lock nut 24, adjusting screw 25, etc.

[0026] like Figures 1-6 As shown, the present invention is a pressure-protected water medium swashplate axial piston pump, including a housing 4. One end of the housing 4 is axially sealed to an inlet / outlet flange 3, and the outer end face of the inlet / outlet flange 3 is fastened to a front cover plate 2. The other end of the housing 4 is axially fixed to a rear end cover 12.

[0027] The main shaft 1 is rotatably mounted on the inlet / outlet flange 3 and the front cover plate 2. The shaft diameter of the main shaft 1 extends into the housing 4 and is connected to the inner hole of the cylinder body 7. A main spring is provided in the inner hole of the cylinder body 7 corresponding to the end of the main shaft 1. A ball joint 11 is provided on the end face of the inner hole of the cylinder body 7. The main spring is pressed against the ball joint 11. The ball joint 11 is connected to the return plate 10. A plunger 8 is provided on the outer ring of the cylinder body 7 corresponding to the inner hole. The return plate 10 and the plunger 8 press the slipper 9 against the first inclined surface 15-1 of the swashplate 15. A rotating steel ball is provided between the second inclined surface 15-2 of the swashplate 15 and the contact surface of the rear cover 12. The swashplate 15 is also provided with a third inclined surface 15-3. The third inclined surface 15-3 extends to the outer end of the second inclined surface 15-2 and forms an obtuse angle with the second inclined surface 15-2. The third inclined surface 15-3 and the second inclined surface 15-2 form the swashplate movement axis 15-5.

[0028] A control valve assembly 16 is provided on the inlet / outlet flange 3. The control valve assembly 16 includes a valve housing 17. The valve housing 17 is provided with a high-pressure water port 3-1 and a control water port 3-2. The valve housing 17 is provided with a control mechanism to control the connection or disconnection of the high-pressure water port 3-1 and the control water port 3-2. The control water port 3-2 is connected to one end of the flow channel on the housing 4. The other end of the flow channel extends to the support 14 on the rear end cover 12. The support 14 can move axially relative to the rear end cover 12, and a support spring 13 is provided between the support 14 and the rear end cover 12. The high-pressure water port 3-1 is connected to the water pump outlet provided on the inlet / outlet flange 3.

[0029] The control mechanism includes a nut 23 connected to the axial hole of the valve housing 17. A plug 19 is also provided in the axial hole of the valve housing 17. A variable valve core 20 is provided between the plug 19 and the nut 23. A spring seat 22 and a spring 21 are provided in the inner hole of the nut 23. The spring 21 and the spring seat 22 are fastened together. The other end of the spring 21 is pressed against one axial end of the variable valve core 20. The other axial end of the variable valve core 20 passes through the end through hole of the plug 19 and is pressed against the control steel ball 18 provided on the outside of the plug 19. The steel ball 18 is used to adjust the opening and closing of the control port 3-2. There is a movement gap between the axial ends of the variable valve core 20 and the nut 20.

[0030] The variable valve core 20 has a limiting flange on its core body. The core body of the variable valve core 20 corresponding to the limiting flange extends into the nut 23. The end of the core body of the variable valve core 20 corresponding to the limiting flange on the other side has an axial extension. The axial extension passes through the end through hole of the plug 19.

[0031] The inlet and outlet flanges 3 are fixed to the distribution plate 5 on one side of the shell 4, and the cylinder body 7 is equipped with a floating plate 6 on one side of the distribution plate 5.

[0032] Semi-circular ball sockets 15-4 are respectively provided on the second inclined surface 15-2 of the rear end cover 12 and the swash plate 15, and rotating steel balls are provided in the ball sockets 15-4 that cooperate with each other on the second inclined surface 15-2 of the rear end cover 12 and the swash plate 15.

[0033] The working process of the product of this invention is as follows: the main shaft 1 is driven to rotate, thereby driving the cylinder 7 to rotate. The cylinder 7 drives the plunger 8, the slipper 9, the return plate 10, and the floating plate 6 to rotate. Under the combined action of the central spring, the ball joint 11, and the return plate 10, the slipper 9 is in close contact with the variable displacement swashplate 15 to rotate. This realizes that the plunger 8 reciprocates relative to the cylinder 7, realizing the water pump's suction and discharge process.

[0034] When the water pump outlet pressure is lower than the set pressure of the control valve assembly 16, the control steel ball 18 in the control valve assembly 16 is pressed against the left cone surface of the valve body 17 under the action of the spring 21. At this time, the control oil port in the control valve assembly 16 is connected to the low pressure chamber 3-3, that is, the bottom of the support 14 is at low pressure, the water pump swashplate angle is α, and the water pump works normally.

[0035] When the pump outlet pressure exceeds the set pressure of the control valve assembly 16, the control ball 18 in the control valve assembly 16 overcomes the action of the spring 21 under the action of high-pressure water, pressing the control ball tightly onto the conical surface of the screw plug 19. At this time, the control port closes with the low-pressure chamber 3-3 and simultaneously connects with the high-pressure port, meaning the bottom of the support 14 is under high pressure. Under the action of high-pressure water, the support 14 pushes the variable angle swashplate 15, using the steel balls in the two ball sockets 15-4 at the bottom as fulcrums, to swing along the swashplate's variable axis to a position where the small plane fits against the pump's rear end cover 12. At this time, the pump swashplate angle becomes (α-β), and the pump switches to a small displacement. At this displacement, the pump's output flow is only used to compensate for system leakage to maintain the pressure required for pump variable displacement, and the output power is almost zero. This achieves protection for the pump and other system components.

Claims

1. A swashplate axial piston pump with pressure protection for water medium, characterized in that: Includes a housing (4), one end of which is axially sealed to an inlet / outlet flange (3), the outer end face of the inlet / outlet flange (3) is fastened to a front cover plate (2), and the other end of the housing (4) is fixed to a rear end cover (12). The main shaft (1) is rotatably mounted on the inlet / outlet flange (3) and the front cover plate (2). The shaft diameter of the main shaft (1) extending into the housing (4) is fitted into the inner hole of the cylinder body (7). A main spring is provided in the inner hole of the cylinder body (7) corresponding to the end of the main shaft (1). A ball joint (11) is fitted on the end face of the inner hole of the cylinder body (7). The main spring is pressed against the ball joint (11). The ball joint (11) is fitted into the return plate (10). A plunger (8) is provided on the outer ring of the cylinder body (7) corresponding to the inner hole. The return plate (10) and the plunger (8) are fitted into the cylinder body (7). The plug (8) presses the slipper (9) against the first inclined surface (15-1) of the swashplate (15). A rotating steel ball is provided between the second inclined surface (15-2) of the swashplate (15) and the contact surface of the rear end cover (12). The swashplate (15) is also provided with a third inclined surface (15-3). The third inclined surface (15-3) extends to the outer end of the second inclined surface (15-2) and forms an obtuse angle with the second inclined surface (15-2). The swashplate movement axis (15-5) is formed between the third inclined surface (15-3) and the second inclined surface (15-2). A control valve assembly (16) is provided on the inlet / outlet flange (3). The control valve assembly (16) includes a valve housing (17). A high-pressure water port (3-1) and a control water port (3-2) are provided on the valve housing (17). A control mechanism is provided on the valve housing (17) to control the connection or disconnection of the high-pressure water port (3-1) and the control water port (3-2). The control water port (3-2) is connected to one end of the flow channel on the housing (4). The other end of the flow channel extends to the support (14) on the rear end cover (12). The support (14) can move axially relative to the rear end cover (12). A support spring (13) is provided between the support (14) and the rear end cover (12). The high-pressure water port (3-1) is connected to the water pump outlet provided on the inlet / outlet flange (3). Semi-circular ball sockets (15-4) are respectively provided on the second inclined surface (15-2) of the rear end cover (12) and the swashplate (15), and rotating steel balls are provided in the ball sockets (15-4) that cooperate with each other on the second inclined surface (15-2) of the rear end cover (12) and the swashplate (15). When the pump outlet pressure is lower than the set pressure of the control valve assembly (16) during operation, the control ball (18) in the control valve assembly (16) is pressed against the left cone surface of the valve body (17) under the action of the spring (21). At this time, the control oil port in the control valve assembly (16) is connected to the low pressure chamber (3-3), the bottom of the support (14) is at low pressure, and the pump works normally. When the pump outlet pressure is higher than the set pressure of the control valve assembly (16), the control steel ball (18) in the control valve assembly (16) overcomes the action of the spring (21) under the action of high pressure water, and presses the control steel ball on the conical surface of the screw plug (19). At this time, the control water port is closed with the low pressure chamber (3-3) and connected with the high pressure water port. The bottom of the support (14) is under high pressure. Under the action of high pressure water, the support (14) pushes the variable angle swashplate (15) with the steel balls in the two ball sockets (15-4) at the bottom as the fulcrum, and swings along the swashplate's variable axis to the position where the small plane fits against the pump's rear end cover (12). The pump switches to a small displacement. There is a movement clearance between the variable valve core (20) and the axial end of the nut (23).

2. The swashplate axial piston pump with pressure protection for water medium as described in claim 1, characterized in that: The control mechanism includes a nut (23) connected to the axial hole of the valve housing (17). A plug (19) is also provided in the axial hole of the valve housing (17). A variable valve core (20) is provided between the plug (19) and the nut (23). A spring seat (22) and a spring (21) are provided in the inner hole of the nut (23). The spring (21) is fastened to the spring seat (22). The other end of the spring (21) is pressed against one axial end of the variable valve core (20). The other axial end of the variable valve core (20) passes through the end through hole of the plug (19) and is pressed against the control steel ball (18) provided on the outside of the plug (19). The steel ball (18) is used to adjust the opening and closing of the control port (3-2).

3. The swashplate axial piston pump with pressure protection for water medium as described in claim 2, characterized in that: The variable valve core (20) has a limiting flange on its core body. The core body of the variable valve core (20) corresponding to the limiting flange extends into the nut (23). The end of the core body of the variable valve core (20) corresponding to the limiting flange on the other side is provided with an axial extension. The axial extension passes through the end through hole of the plug (19).

4. The swashplate axial piston pump with pressure protection for water medium as described in claim 1, characterized in that: The inlet and outlet flanges (3) are fixed to the distribution plate (5) on one side of the shell (4), and the cylinder (7) is provided with a floating plate (6) on one side of the distribution plate (5).

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