Integrated hydraulic cylinder

Abstract

The utility model provides an integrated hydraulic cylinder which comprises a cylinder body, a piston and a piston rod, the piston and the piston rod are arranged in the cylinder body, an inner cavity of the cylinder body is divided into a rod cavity and a rodless cavity by the piston and the piston rod, the outer wall of the cylinder body is sleeved with an oil tank sleeve, and the oil tank sleeve is arranged at the two ends of the oil tank sleeve and used for storing hydraulic oil. The oil tank sleeve is communicated with the electric control valve group device through a pipeline, and the electric control valve group device is communicated with a cavity of the oil tank sleeve; a pump head is further arranged at one end of the cylinder body and is communicated with the electric control valve group device through a pipeline; the motor is mechanically connected with the pump head to drive the pump head to supply liquid; and a compressed air bag is arranged in the oil tank sleeve so as to compensate the volume difference between the rod cavity and the rodless cavity. The hydraulic oil tank and the hydraulic cylinder are integrated together, so that the problem that an existing hydraulic cylinder is provided with more pipelines to be connected with the hydraulic oil tank is solved, and the problem that the thrust of an electric push rod is insufficient is solved. The compressed air bag can make up the volume difference between the rod cavity and the rodless cavity.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinders, and in particular to an integrated hydraulic cylinder. Background Technology

[0002] Existing hydraulic cylinders require piping to connect to a hydraulic power unit, which supplies high-pressure hydraulic oil to drive the piston rod. However, when using a large number of hydraulic cylinders, these piping lines significantly interfere with their operation. A structure integrating the hydraulic power unit and hydraulic cylinders is needed for easier mobility and cluster deployment. Chinese patent document CN115711247A describes an integrated electro-hydraulic actuation device and its control method based on magnetic modulation. It integrates the motor, oil tank, and vane pump outside the cylinder body, achieving integration and eliminating the need for an external oil tank, thus greatly improving portability. However, the vane pump is a rotary positive displacement pump, and the hydraulic oil pressure output by the vane pump is relatively low, resulting in insufficient output force from the hydraulic cylinder. Furthermore, this structure is very complex, leading to insufficient space in the oil tank, and the hydraulic cylinder can only adopt a double-ended piston rod structure, further affecting the thrust of the hydraulic cylinder. At this thrust, a simpler electric actuator can replace it, making this structure lack usable application scenarios. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide an integrated hydraulic cylinder that can significantly reduce the overall size of the hydraulic cylinder system, improve the mobility of the hydraulic cylinder, and facilitate its use as a power component in high-power equipment.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: an integrated hydraulic cylinder, including a cylinder body, a piston and a piston rod disposed in the cylinder body, the piston and piston rod dividing the inner cavity of the cylinder body into a rod chamber and a rodless chamber, an oil tank sleeve is sleeved on the outer wall of the cylinder body, and oil tank end caps are provided at both ends of the oil tank sleeve. The oil tank sleeve is used to store hydraulic oil, and the oil tank sleeve is connected to an electric control valve assembly through a pipeline. The electric control valve assembly is connected to the cavity of the oil tank sleeve.

[0005] A pump head is also provided at one end of the cylinder body. The pump head is connected to the electronically controlled valve assembly through a pipeline. The motor is mechanically connected to the pump head to drive the pump head to supply liquid.

[0006] A compressed air bladder is installed inside the fuel tank sleeve to compensate for the volume difference between the rod chamber and the rodless chamber.

[0007] In a preferred embodiment, multiple support blocks are also provided between the oil tank sleeve and the cylinder block;

[0008] A filter is installed in the cylinder.

[0009] In the preferred embodiment, the motor, pump head, and electronically controlled valve assembly are arranged sequentially along the axial direction;

[0010] The electronically controlled valve assembly is located on the end cap at one end of the rodless chamber of the cylinder.

[0011] In a preferred embodiment, the electronically controlled valve assembly is equipped with a first reversing valve and a second reversing valve. The pump head is connected to the oil inlet of the first reversing valve and the second reversing valve through the first pump head pipeline and the second pump head pipeline, respectively. The oil return ports of the first reversing valve and the second reversing valve are connected to the oil tank sleeve through the first oil return pipeline and the second oil return pipeline, respectively.

[0012] The drain port of the first directional valve is connected to the rod chamber through the first cylinder body pipeline, and the drain port of the second directional valve is connected to the rodless chamber through the second cylinder body pipeline.

[0013] The first pump head pipeline and the second pump head pipeline are connected to the pump head through a main pipe. An overflow valve is installed on the main pipe, and the overflow port of the overflow valve is connected to the oil tank sleeve.

[0014] In a preferred embodiment, a stroke sensor is also provided on the piston or piston rod to detect the stroke of the piston rod;

[0015] The travel sensor is one or more of the following: magnetostrictive linear displacement sensor, inductive proximity switch, resistive displacement sensor, photoelectric sensor, Hall effect sensor, ultrasonic sensor, incremental or absolute encoder, or magnetic encoder.

[0016] In a preferred embodiment, a battery is provided at the end of the motor, and the battery is electrically connected to the motor.

[0017] In a preferred embodiment, a pressure sensor is provided on the main pipe or the first pump head pipe and the second pump head pipe;

[0018] A flow sensor is installed on the main pipe or the first pump head pipe and the second pump head pipe;

[0019] It also has a main control system, in which the main control chip is electrically connected to the stroke sensor, pressure sensor and flow sensor;

[0020] The main control chip is also electrically connected to the relief valve, the first directional valve, the second directional valve, and the motor to drive the relief valve, the first directional valve, the second directional valve, and the motor to operate.

[0021] In the preferred embodiment, the main control chip is also electrically connected to the overflow valve, the first directional valve, the second directional valve, and the feedback module of the motor.

[0022] In a preferred embodiment, there are multiple integrated hydraulic cylinders, and the main control chip of each integrated hydraulic cylinder is electrically connected to one or more communication chips to communicate with a host computer or host network through the communication chips.

[0023] It also includes a time synchronization chip, which is electrically connected to each main control chip to achieve synchronization of the main control chips.

[0024] In a preferred embodiment, the pump head is a gear pump. The pump head housing is provided with a meshing drive gear and a driven gear. The end faces of the drive gear and the driven gear, as well as the outer edge faces away from the meshing position, form a sealing structure with the housing, dividing the inner cavity of the housing into two chambers. The two chambers constitute a high-pressure chamber and a low-pressure chamber according to the different rotation directions of the drive gear. Each chamber is provided with a liquid port, which is connected to the first pump head pipeline and the second pump head pipeline, respectively.

[0025] Alternatively, the pump head is an axial piston pump, and the piston cylinder is provided with multiple piston chambers arranged along the motor axis and circumference. Multiple pistons are slidably installed in the piston chambers. An eccentric disk is also provided at the end of the piston. The eccentric disk contacts the end of the piston and is fixedly connected to the output shaft of the motor to drive the eccentric disk to rotate and drive each piston to reciprocate.

[0026] The bottom of each plunger chamber is connected to a drain check valve and a feed check valve, which are respectively connected to the first pump head pipeline and the second pump head pipeline.

[0027] This utility model provides an integrated hydraulic cylinder, which has the following advantages:

[0028] 1. This utility model integrates the hydraulic oil tank and the hydraulic cylinder, solving the problem of existing hydraulic cylinders having numerous pipelines connected to the hydraulic oil tank. Furthermore, the thrust generated by the hydraulic cylinder also addresses the issue of insufficient thrust from the electric actuator. This utility model achieves a balance between high thrust and portability.

[0029] 2. This utility model has a compressed air bladder installed in the hydraulic oil tank, which can compensate for the volume difference between the rod chamber and the rodless chamber.

[0030] 3. The structure of this utility model simplifies the power design of some complex mechanical mechanisms, provides high-power power for compact equipment such as robots and special equipment, and lays the foundation for realizing ready-to-use equipment.

[0031] 4. The intelligent single-control or group-control system of this utility model can realize automated control or even intelligent control, enabling clustered equipment to complete complex actions. Attached Figure Description

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0033] Figure 1 This is a cross-sectional view of the overall structure of this utility model.

[0034] Figure 2This is a schematic diagram of the power structure of this utility model.

[0035] Figure 3 This is a schematic diagram of the cross-sectional structure of the pump head of this utility model.

[0036] Figure 4 This is a schematic diagram of the vertical cross-sectional structure of another preferred pump head of this utility model.

[0037] Figure 5 This invention relates to a single-control automated control system.

[0038] Figure 6 This invention relates to a group control intelligent control system.

[0039] In the diagram: Motor 1, Pump head 2, Housing 201, Inlet 202, Drive gear 203, Driven gear 204, Outlet 205, Eccentric disc 206, Plunger 207, Plunger cavity 208, Plunger cylinder 209, Return spring 210, Drain check valve 211, Inlet check valve 212, Electrically controlled valve assembly 3, Overflow valve 31, First directional valve 32, Second directional valve 33, Pressure sensor 34, Flow sensor 35, First cylinder tube 4. Second cylinder pipe 5. Oil tank sleeve 6. Cylinder 7. Piston 8. Piston rod 9. Compression air bag 10. Battery 11. First pump head pipe 12. Second pump head pipe 13. First return oil pipe 14. Second return oil pipe 15. Oil tank cavity 16. Support block 17. Filter 18. Oil tank end cover 19. Stroke sensor 20. Hydraulic cylinder 100. Main control system 200. Main control chip 220. Communication chip 221. Time synchronization chip 222. Detailed Implementation

[0040] Example 1:

[0041] like Figure 1 , 2 As shown, an integrated hydraulic cylinder includes a cylinder body 7, a piston 8 and a piston rod 9 disposed inside the cylinder body 7. The piston 8 and piston rod 9 divide the inner cavity of the cylinder body 7 into a rod chamber and a rodless chamber. An oil tank sleeve 6 is sleeved on the outer wall of the cylinder body 7. Oil tank end caps 19 are provided at both ends of the oil tank sleeve 6. The oil tank sleeve 6 is used to store hydraulic oil. The oil tank sleeve 6 is connected to an electronically controlled valve assembly 3 through a pipeline. The electronically controlled valve assembly 3 is connected to the cavity of the oil tank sleeve 6.

[0042] like Figure 1 , 2 As shown, a pump head 2 is also provided at one end of the cylinder body 7. The pump head 2 is connected to the electronically controlled valve assembly 3 through a pipeline. The motor 1 is mechanically connected to the pump head 2 to drive the pump head 2 to supply liquid.

[0043] like Figure 1As shown, a compression bladder 10 is provided inside the oil tank sleeve 6 to compensate for the volume difference between the rod chamber and the rodless chamber. When all the hydraulic oil enters the rodless chamber, the compression bladder 10 expands to fill the missing space. When all the hydraulic oil enters the rod chamber, the return oil volume increases, and the compression bladder 10 contracts to provide space for the excess hydraulic oil. Preferably, the compression bladder 10 is an annular bladder.

[0044] This structure ensures that the cavity of the tank sleeve 6 can still function normally in a sealed state.

[0045] Preferred solutions include Figure 1 In the middle, multiple support blocks 17 are also provided between the oil tank sleeve 6 and the cylinder body 7;

[0046] like Figure 1 In the middle, a filter 18 is provided in the cylinder 7.

[0047] Preferred solutions include Figure 1 In the middle, motor 1, pump head 2 and electronically controlled valve assembly 3 are arranged sequentially along the axial direction;

[0048] The electronically controlled valve assembly 3 is located on the end cap at one end of the rodless chamber of the cylinder 7. This structure makes the overall structure more compact.

[0049] Preferred solutions include Figure 2 In the middle, the electronically controlled valve group device 3 is equipped with a first reversing valve 32 and a second reversing valve 33. The pump head 2 is connected to the oil inlet of the first reversing valve 32 and the second reversing valve 33 through the first pump head pipeline 12 and the second pump head pipeline 13 respectively. The oil return ports of the first reversing valve 32 and the second reversing valve 33 are connected to the oil tank sleeve 6 through the first oil return pipeline 14 and the second oil return pipeline 15 respectively.

[0050] The oil outlet of the first directional valve 32 is connected to the rod chamber through the first cylinder pipe 4, and the oil outlet of the second directional valve 33 is connected to the rodless chamber through the second cylinder pipe 5.

[0051] The first pump head pipeline 12 and the second pump head pipeline 13 are connected to the pump head 2 through a main pipe. An overflow valve 31 is provided on the main pipe, and the overflow port of the overflow valve 31 is connected to the oil tank sleeve 6.

[0052] Preferred solutions include Figure 3 In the above, the pump head 2 is a gear pump. The housing 201 of the pump head 2 is provided with a driving gear 203 and a driven gear 204 that mesh with each other. The end faces of the driving gear 203 and the driven gear 204 and the outer edge faces away from the meshing position form a sealing structure with the housing 201, and divide the inner cavity of the housing 201 into two chambers. The two chambers constitute a high-pressure chamber and a low-pressure chamber according to the different rotation directions of the driving gear 203. Each chamber is provided with a liquid port, which is connected to the first pump head pipeline 12 and the second pump head pipeline 13 respectively.

[0053] Alternatively, another option is as follows: Figure 4 In the above, the pump head 2 is an axial piston pump. The piston cylinder body 209 is provided with a plurality of piston chambers 208 arranged along the axial direction of the motor 1 and along the circumference. A plurality of pistons 207 are slidably installed in the piston chambers 208. An eccentric disk 206 is also provided at the end of the piston 207. The eccentric disk 206 contacts the end of the piston 207. The eccentric disk 206 is fixedly connected to the output shaft of the motor 1 so as to drive the eccentric disk 206 to rotate and drive each piston 207 to reciprocate.

[0054] The bottom end of each plunger chamber 208 is connected to the drain check valve 211 and the inlet check valve 212, which are respectively connected to the first pump head pipeline 12 and the second pump head pipeline 13.

[0055] In addition to the pump head options mentioned above, pump head 2 can also be a vane-type positive displacement pump or a high-pressure diaphragm pump. During operation, pump head 2 outputs hydraulic oil. At this time, the first directional valve 32 switches to the rod chamber of hydraulic cylinder 100, and the second directional valve 33 switches to the oil tank sleeve 6. The piston rod 9 retracts, and the compression bladder 10 contracts. During reversal, the first directional valve 32 switches to the oil tank sleeve 6, and the second directional valve 33 switches to the rodless chamber of hydraulic cylinder 100. The piston rod 9 extends, and the compression bladder 10 inflates.

[0056] Example 2:

[0057] Preferred solutions include Figure 1 In the process, a stroke sensor 20 is also provided on the piston 8 or piston rod 9 to detect the stroke of the piston rod 9;

[0058] The travel sensor 20 is one or more of the following: magnetostrictive linear displacement sensor, inductive proximity switch, resistive displacement sensor, photoelectric sensor, Hall effect sensor, ultrasonic sensor, incremental or absolute encoder, or magnetic encoder.

[0059] Preferred solutions include Figure 1 In this embodiment, a battery 11 is provided at the end of the motor 1, and the battery 11 is electrically connected to the motor 1. The battery 11 is preferably a lithium battery, such as a ternary lithium battery, and adopts a quick-release structure. In this example, the motor 1 is preferably a DC permanent magnet motor or a servo motor.

[0060] Preferred solutions include Figure 2 In the process, a pressure sensor 34 is provided on the main pipe or the first pump head pipe 12 and the second pump head pipe 13;

[0061] A flow sensor 35 is installed on the main pipe or the first pump head pipe 12 and the second pump head pipe 13;

[0062] Pressure sensor 34 and flow sensor 35 are relatively common components.

[0063] like Figure 5 As shown, a main control system 200 is also provided. In the main control system 200, the input port of the main control chip 220 is electrically connected to the stroke sensor 20, the pressure sensor 34 and the flow sensor 35.

[0064] The main control chip 220 is preferably a main control chip 220 with certain wireless communication functions, such as ESP32-S2, ESP32-S3 or STM32 series main control chips. The chip that integrates WIFI wireless communication module is selected as the main control chip so as to improve adaptability through integration with other communication modules.

[0065] The output port of the main control chip 220 is also electrically connected to the overflow valve 31, the first reversing valve 32, the second reversing valve 33 and the motor 1 to drive the overflow valve 31, the first reversing valve 32, the second reversing valve 33 and the motor 1 to operate.

[0066] The relief valve 31 is used to control the pressure of the pipeline. Using a remotely adjustable relief valve 31 facilitates intelligent control, such as the DB / DBW series pilot-operated relief valve, the EDG-01V series proportional relief valve, and the RV-P-02M stacked relief valve. Through precise control of the relief pressure, the integrated hydraulic cylinder of this invention can also achieve some special functions. For example, as a buffer, when facing an impact, such as a high-speed falling construction elevator, the initial relief valve 31 is set to a small relief pressure. After the integrated hydraulic cylinder contacts the falling construction elevator, the relief pressure of the relief valve 31 is gradually increased. This buffers the high-speed impact while slowly decelerating the construction elevator until it comes to a complete stop within the stroke of the integrated hydraulic cylinder. The first directional valve 32 and the second directional valve 33 are preferably 4WE6 series, D03, D05, D08 series, or 4WREE12G24NCDC / 24VDC series directional valves to achieve remote automated control, especially the interlocking synchronous control of the first directional valve 32 and the second directional valve 33.

[0067] Example 3:

[0068] Preferred solutions include Figure 3 In this configuration, the main control chip 220 is also electrically connected to the feedback module of the overflow valve 31, the first reversing valve 32, the second reversing valve 33, and the motor 1. This structure allows for the acquisition of opening information of the overflow valve 31, the first reversing valve 32, and the second reversing valve 33, as well as the rotation angle information of the motor 1, enabling the control system of this invention to achieve higher precision automated control.

[0069] Example 4:

[0070] The greatest advantage of this invention lies in its clustered and intelligent control, enabling the completion of complex engineering construction operations. A preferred solution is as follows: Figure 5 , 6 As shown, there are multiple integrated hydraulic cylinders. Each integrated hydraulic cylinder's main control chip 220 is electrically connected to one or more communication chips 221 to communicate with a host computer or a host network via the communication chips 221. The host computer or host network sends logic control commands, which are then executed by each main control chip 220. The communication chips 221 typically use remote communication modules such as 4G or 5G modules, or less commonly used communication modules such as ZigBee and LoRa modules, to achieve good communication compatibility. Depending on the distance between the integrated hydraulic cylinders, a local area network (LAN) can be formed via wired or WiFi connections. Each LAN has one communication chip 221, communicating with the host computer or host network via a 4G or 5G communication module. Alternatively, sensor data can be collected using ZigBee or LoRa protocols.

[0071] A time synchronization chip 222 is also provided, which is electrically connected to each main control chip 220 to achieve synchronization of the main control chips 220. A common time source is established through the time synchronization chip 222 to ensure that all main control chips 220 trigger operations on the same clock edge, thereby achieving operation synchronization.

[0072] Taking the adjustment of a complex formwork trolley as an example, such as the casting formwork for a large tower column, the BIM design data is first read. At the construction site, the spatial position of the formwork is collected by sensors, including cameras, total stations, or lidar. The actual position is compared with the coordinate position in the design data, thereby generating adjustment data in the network. The control center, such as the centralized control center, distributes the adjustment data to each integrated hydraulic cylinder used to adjust the position of the formwork. Each main control chip 220 receives and confirms the corresponding adjustment data from the communication chip 221, and converts the adjustment data into specific control parameters, such as the rotation angle of motor 1, the overflow pressure parameters of each overflow valve, and the opening parameters of the reversing valve. Each main control chip 220 is synchronized with the assistance of the time synchronization chip 222. Under the control of their respective main control chips 220, each integrated hydraulic cylinder extends or retracts the piston rod 9 at the same or different speeds, so that the formwork is adjusted synchronously.

[0073] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of the claims and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. An integrated hydraulic cylinder, comprising a cylinder body (7), a piston (8) and a piston rod (9) disposed within the cylinder body (7), wherein the piston (8) and the piston rod (9) divide the inner cavity of the cylinder body (7) into a rod-type cavity and a rodless cavity, characterized in that: An oil tank sleeve (6) is fitted on the outer wall of the cylinder body (7). Oil tank end caps (19) are provided at both ends of the oil tank sleeve (6). The oil tank sleeve (6) is used to store hydraulic oil. The oil tank sleeve (6) is connected to the electric control valve assembly (3) through a pipeline. The electric control valve assembly (3) is connected to the cavity of the oil tank sleeve (6). A pump head (2) is also provided at one end of the cylinder (7). The pump head (2) is connected to the electronically controlled valve assembly (3) through a pipeline. The motor (1) is mechanically connected to the pump head (2) to drive the pump head (2) to supply liquid. A compressed air bladder (10) is provided inside the oil tank sleeve (6) to compensate for the volume difference between the rod chamber and the rodless chamber.

2. The integrated hydraulic cylinder according to claim 1, characterized in that: in Multiple support blocks (17) are also provided between the oil tank sleeve (6) and the cylinder body (7); A filter (18) is provided in the cylinder (7).

3. The integrated hydraulic cylinder according to claim 1, characterized in that: The motor (1), pump head (2), and electrically controlled valve assembly (3) are arranged sequentially along the axial direction; The electronically controlled valve assembly (3) is located on the end cap at one end of the rodless chamber of the cylinder (7).

4. The integrated hydraulic cylinder according to any one of claims 1 to 3, characterized in that: it is electrically controlled. The valve assembly (3) is equipped with a first reversing valve (32) and a second reversing valve (33). The pump head (2) is connected to the oil inlet of the first reversing valve (32) and the second reversing valve (33) through the first pump head pipeline (12) and the second pump head pipeline (13), respectively. The oil return ports of the first reversing valve (32) and the second reversing valve (33) are connected to the oil tank sleeve (6) through the first oil return pipeline (14) and the second oil return pipeline (15), respectively. The oil outlet of the first reversing valve (32) is connected to the rod chamber through the first cylinder pipe (4), and the oil outlet of the second reversing valve (33) is connected to the rodless chamber through the second cylinder pipe (5). The first pump head pipeline (12) and the second pump head pipeline (13) are connected to the pump head (2) through a section of main pipe. An overflow valve (31) is provided on the main pipe, and the overflow port of the overflow valve (31) is connected to the oil tank sleeve (6).

5. The integrated hydraulic cylinder according to claim 4, characterized in that: A stroke sensor (20) is also provided on the piston (8) or piston rod (9) to detect the stroke of the piston rod (9); The travel sensor (20) is one or more of the following: magnetostrictive linear displacement sensor, inductive proximity switch, resistive displacement sensor, photoelectric sensor, Hall effect sensor, ultrasonic sensor, incremental or absolute encoder or magnetic encoder.

6. The integrated hydraulic cylinder according to claim 5, characterized in that: A battery (11) is provided at the end of the motor (1), and the battery (11) is electrically connected to the motor (1).

7. The integrated hydraulic cylinder according to claim 6, characterized in that: in Pressure sensors (34) are provided on the main pipe or the first pump head pipe (12) and the second pump head pipe (13). A flow sensor (35) is provided on the main pipe or the first pump head pipe (12) and the second pump head pipe (13); It also includes a main control system (200), in which the main control chip (220) is electrically connected to the stroke sensor (20), the pressure sensor (34) and the flow sensor (35); The main control chip (220) is also electrically connected to the overflow valve (31), the first reversing valve (32), the second reversing valve (33) and the motor (1) to drive the overflow valve (31), the first reversing valve (32), the second reversing valve (33) and the motor (1) to operate.

8. The integrated hydraulic cylinder according to claim 7, characterized in that: The main control chip (220) is also electrically connected to the feedback module of the overflow valve (31), the first reversing valve (32), the second reversing valve (33) and the motor (1).

9. The integrated hydraulic cylinder according to claim 8, characterized in that: The integrated hydraulic cylinder is multiple, and the main control chip (220) of each integrated hydraulic cylinder is electrically connected to one or more communication chips (221) to communicate with the host computer or host network through the communication chip (221); It also includes a time synchronization chip (222), which is electrically connected to each main control chip (220) to achieve synchronization of the main control chips (220).

10. The integrated hydraulic cylinder according to any one of claims 1-3 and 5-9, characterized in that: The pump head (2) is a gear pump. The housing (201) of the pump head (2) is provided with a driving gear (203) and a driven gear (204) that mesh with each other. The end faces of the driving gear (203) and the driven gear (204) and the outer edge faces away from the meshing position form a sealing structure with the housing (201) and divide the inner cavity of the housing (201) into two chambers. The two chambers form a high-pressure chamber and a low-pressure chamber according to the different rotation directions of the driving gear (203). Each chamber is provided with a liquid port, which is connected to the first pump head pipeline (12) and the second pump head pipeline (13) respectively. Alternatively, the pump head (2) is an axial piston pump. The piston cylinder (209) is provided with multiple piston chambers (208) arranged along the axial direction of the motor (1) and along the circumference. Multiple pistons (207) are slidably installed in the piston chambers (208). An eccentric disk (206) is also provided at the end of the piston (207). The eccentric disk (206) contacts the end of the piston (207). The eccentric disk (206) is fixedly connected to the output shaft of the motor (1) so as to drive the eccentric disk (206) to rotate and drive each piston (207) to reciprocate. The bottom end of each plunger chamber (208) is connected to the drain check valve (211) and the inlet check valve (212), and the drain check valve (211) and the inlet check valve (212) are respectively connected to the first pump head pipeline (12) and the second pump head pipeline (13).

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