A large displacement coaxial four-stage high-pressure pump
By designing a large-displacement coaxial four-stage high-pressure pump, and adopting a four-cylinder synchronous coaxial operation and cooling chamber structure, the problems of excessive machine temperature and piston ring wear caused by increased exhaust volume in the existing technology have been solved, achieving efficient and stable high-pressure delivery and processing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANTONG GUANGXING PNEUMATIC EQUIP
- Filing Date
- 2025-12-15
- Publication Date
- 2026-06-23
AI Technical Summary
The existing method of increasing the exhaust volume of a three-stage high-pressure pump can lead to problems such as excessively high machine temperature, piston ring wear, and increased machine load.
Design a large-displacement coaxial four-stage high-pressure pump, which uses four cylinders to operate synchronously and coaxially. The three pistons are driven to slide synchronously in the same direction, while the other two cylinders expand synchronously in opposite directions. Combined with the cooling chamber structure, the synchronous compression and expansion of the four cylinders are achieved.
The increased exhaust volume of the high-pressure pump ensures stable operation of the drive components, reduces machine temperature and piston ring wear, and meets the requirements of high-pressure conveying and processing.
Smart Images
Figure CN121382583B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of gas compression device technology, and in particular to a large-displacement coaxial four-stage high-pressure pump. Background Technology
[0002] High-pressure air pumps are widely used in daily production and life as air compression equipment. They are usually divided into single-stage and multi-stage. The higher the number of stages, the greater the pressure boosting efficiency.
[0003] The existing three-stage high-pressure pump has a composite cylinder body that is nested in sequence. That is, the third-stage cylinder (or high-pressure cylinder) is located on the innermost side, so that the volume of the three-stage cylinder decreases in sequence to achieve the purpose of increasing pressure step by step.
[0004] To better serve various high-pressure conveying and processing needs, the original three-stage high-pressure pump needs to increase its exhaust volume. However, according to the existing technology, the only way to increase the exhaust volume of the high-pressure pump is to increase the motor output speed by increasing the cylinder diameter or reducing the reduction ratio, or to increase the cylinder diameter. However, increasing the motor speed will cause the machine temperature to be too high and increase the wear of the piston rings, while increasing the cylinder diameter will increase the load on the machine.
[0005] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention
[0006] The purpose of this application is to provide a large-displacement coaxial four-stage high-pressure pump to solve the problems of excessive machine temperature, increased piston ring wear, and increased machine load caused by increasing the displacement of traditional three-stage high-pressure pumps.
[0007] To achieve the above objectives, this application provides the following technical solution:
[0008] This application provides a large-displacement coaxial four-stage high-pressure pump, comprising: four cylinders coaxially arranged inside the cylinder body, wherein the piston of one cylinder is fixed inside the cylinder body, and the pistons of the other three cylinders are integrally assembled. By driving the three integrally assembled pistons to slide synchronously and in the same direction inside the cylinder body, two of the cylinders can be compressed synchronously and in the same direction to reduce their volume, while the other two cylinders expand synchronously in the opposite direction to increase their volume.
[0009] Preferably, a crankcase is installed at one end of the cylinder block, and a motor is installed on one side of the crankcase to drive the crankshaft inside the crankcase to rotate.
[0010] The crankshaft inside the crankcase is connected to the piston inside the cylinder via a connecting rod, with the two ends of the connecting rod hinged to the crankshaft and the piston inside the cylinder, respectively.
[0011] Preferably, a high-pressure cylinder seat is installed at one end of the cylinder body and a primary connecting seat is installed at the other end, and the primary connecting seat is fixed to the crankcase. A fourth-stage cylinder liner extends from the middle of the high-pressure cylinder seat to the other end of the cylinder body.
[0012] The extended end of the fourth-stage cylinder liner is fitted with a third-stage piston, that is, the extended end of the fourth-stage cylinder liner is inserted into the tail of the third-stage piston for sealing and fixing.
[0013] The third-stage piston has a channel at its shaft center that communicates with the cavity of the fourth-stage cylinder liner.
[0014] Preferably, a third-stage inner cylinder liner extends from the middle of the high-pressure cylinder seat to the other end of the cylinder body, and the fourth-stage cylinder liner is located in the center of the third-stage inner cylinder liner, so that a first-stage cooling chamber is formed between the fourth-stage cylinder liner and the third-stage inner cylinder liner.
[0015] The extended end sealing sleeve of the third-stage inner cylinder liner is located on the outer side of the tail of the third-stage piston, and the outer diameter of the third-stage inner cylinder liner is smaller than the head diameter of the third-stage piston.
[0016] Preferably, the cylinder block is composed of a primary cylinder liner and a secondary cooling chamber sleeve, and the primary cylinder liner and the secondary cooling chamber sleeve are connected by a primary cylinder seat.
[0017] The end of the first-stage cylinder liner furthest from the first-stage cylinder seat is connected to the high-pressure cylinder seat, and the end of the second-stage cooling chamber sleeve furthest from the first-stage cylinder seat is connected to the first-stage connecting seat.
[0018] The end of the first-stage cylinder seat facing the second-stage cooling chamber sleeve is connected to a second-stage connecting seat.
[0019] Preferably, a secondary cylinder liner is coaxially sleeved inside the secondary cooling chamber sleeve, so that a secondary cooling chamber is formed between the secondary cooling chamber sleeve and the secondary cylinder liner;
[0020] The first-stage piston, first-stage connecting seat, second-stage connecting seat, and first-stage cylinder seat are all annular, so that the two ends of the second-stage cylinder liner are respectively fixedly sealed inside the annular openings of the first-stage connecting seat and the second-stage connecting seat, and the head of the third-stage piston extends into the annular opening of the first-stage cylinder seat, and the diameter of the head of the third-stage piston is smaller than the diameter of the annular opening of the first-stage cylinder seat.
[0021] Preferably, the fourth-stage cylinder liner is fitted with a sliding seal and a fourth-stage piston to form a fourth-stage cylinder with the high-pressure cylinder seat. The high-pressure cylinder seat is provided with a high-pressure one-way valve and a high-pressure outlet. The high-pressure one-way valve enables the fourth-stage cylinder to be unidirectionally connected to the high-pressure outlet.
[0022] A first-stage piston is slidably disposed inside the first-stage cylinder liner, and the first-stage piston is slidably sealed to the outside of the third-stage inner cylinder liner; a second-stage piston is slidably disposed inside the second-stage cylinder liner.
[0023] The end of the secondary piston facing the crankcase is hinged to the end of the connecting rod.
[0024] A piston rod is connected between the middle of the fourth-stage piston and the second-stage piston.
[0025] Preferably, a third-stage outer cylinder liner is connected between the first-stage piston and the second-stage piston. The end of the third-stage outer cylinder liner that connects with the first-stage piston is slidably sealed to the outside of the third-stage piston, so that the second-stage cylinder liner, the second-stage piston and the third-stage piston together constitute the second-stage cylinder. The third-stage outer cylinder liner and the third-stage inner cylinder liner also form a third-stage cylinder. At the same time, the third-stage outer cylinder liner is slidably sealed to the annulus of the first-stage cylinder seat to form the first-stage cylinder.
[0026] The outer diameter of the third-stage outer cylinder liner is smaller than the inner diameter of the second-stage cylinder liner, so that an intake passage is formed between the third-stage outer cylinder liner and the second-stage cylinder liner, and the end of the third-stage outer cylinder liner near the second-stage piston is provided with an air hole that communicates with the intake passage.
[0027] Preferably, the first-stage cylinder seat is provided with an air inlet, a first-stage one-way valve, and a second-stage one-way valve;
[0028] The first-stage one-way valve enables the air inlet to be connected to the first-stage cylinder in one direction.
[0029] The two-stage one-way valve enables the first-stage cylinder to be unidirectionally connected to the second-stage cylinder.
[0030] The third-stage piston is equipped with a three-stage one-way valve, and the fourth-stage piston is equipped with a four-stage one-way valve.
[0031] The three-stage one-way valve enables one-way communication between the second-stage cylinder and the third-stage cylinder, and the four-stage one-way valve enables one-way communication between the third-stage cylinder and the fourth-stage cylinder.
[0032] The high-pressure cylinder seat is provided with a breather hole, through which air is supplied to the cylinder body between the first-stage piston and the high-pressure cylinder seat for intake and exhaust.
[0033] Preferably, the high-pressure cylinder seat is also provided with a water outlet that connects to the primary cooling chamber;
[0034] The primary connecting seat is provided with a water inlet that connects to the secondary cooling chamber;
[0035] A delivery pipe is connected between the high-pressure cylinder seat and the first-stage connecting seat. The delivery pipe connects the first-stage cooling chamber and the second-stage cooling chamber, so that the outlet and inlet are connected to an external cold source, allowing the cooling medium to circulate between the cooling chamber and the external cold source.
[0036] Compared with the closest prior art, the technical solution of this application has the following beneficial effects:
[0037] This application enables four cylinders to operate synchronously, greatly improving the compression ratio and thus effectively increasing the exhaust volume of the high-pressure pump to meet the needs of high-pressure transmission and processing. Furthermore, the pistons of the four cylinders in this application operate in the same direction, which can ensure the balance of crankshaft tension and pressure, making it efficient and stable in operation. Attached Figure Description
[0038] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein:
[0039] Figure 1 This is a schematic diagram of the front sectional view of this application;
[0040] Figure 2 for Figure 1 Enlarged view of point A in the middle;
[0041] Figure 3 This is a schematic side view sectional view of this application;
[0042] Figure 4 for Figure 3 A magnified view of a portion of the image.
[0043] In the diagram: 1. Crankcase; 2. Motor; 3. Crankshaft; 4. Connecting rod; 5. High-pressure cylinder head; 6. First-stage connecting seat; 7. Fourth-stage cylinder liner; 8. Third-stage piston; 9. Third-stage inner cylinder liner; 10. First-stage cooling chamber; 11. Delivery pipe; 12. First-stage cylinder liner; 13. Second-stage cooling chamber sleeve; 14. First-stage cylinder head; 15. Second-stage connecting seat; 16. Second-stage cylinder liner; 17. Second-stage cooling chamber; 18. Fourth-stage piston; 19. Fourth-stage cylinder; 2 0. High-pressure check valve; 21. High-pressure outlet; 22. First-stage piston; 23. Second-stage piston; 24. Piston rod; 25. Third-stage outer cylinder liner; 26. Second-stage cylinder; 27. Third-stage cylinder; 28. First-stage cylinder; 29. Intake passage; 30. Air hole; 31. Inlet; 32. First-stage check valve; 33. Second-stage check valve; 34. Third-stage check valve; 35. Fourth-stage check valve; 36. Breathing hole; 37. Outlet; 38. Inlet. Detailed Implementation
[0044] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.
[0045] In the following description, the terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.
[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to limit this disclosure.
[0047] In the description of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and do not require that this application be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. The terms "connected," "linked," and "set up" used in this application should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; direct connections or indirect connections through intermediate components; wired connections, radio connections, or wireless communication signal connections. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0048] This application provides a large-displacement coaxial four-stage high-pressure pump. By employing four cylinders to operate synchronously and coaxially, the pump's exhaust volume is increased, and the stable operation of the drive components is ensured.
[0049] Example, refer to Figure 1 and Figure 3The four-stage high-pressure pump includes a cylindrical cylinder body. The upper part of the cylinder body is a primary cylinder liner 12, and the lower part of the cylinder body is a secondary cooling chamber sleeve 13. A primary cylinder seat 14 is fixedly connected between the primary cylinder liner 12 and the secondary cooling chamber sleeve 13. A high-pressure cylinder seat 5 is fixedly and sealed to the upper end of the primary cylinder liner 12, and a primary connecting seat 6 is fixedly and sealed to the lower end of the secondary cooling chamber sleeve 13. A crankcase 1 is installed at the bottom of the primary connecting seat 6. A motor 2 is fixed on the right side of the crankcase 1. The shaft of the motor 2 extends into the crankcase 1 and is connected to the crankshaft 3 so that the motor 2 controls the rotation of the crankshaft 3. The crankshaft 3 in the crankcase 1 is connected to the piston located in the cylinder body through a connecting rod 4. The two ends of the connecting rod 4 are respectively hinged to the piston of the crankshaft 3 and the cylinder body.
[0050] Reference Figure 3 and Figure 4 A fourth-stage cylinder liner 7 extends vertically downward from the middle of the high-pressure cylinder seat 5. A fourth-stage piston 18 is fitted inside the fourth-stage cylinder liner 7 in a sliding sealing fit to form a fourth-stage cylinder 19 with the high-pressure cylinder seat 5. A high-pressure one-way valve 20 is provided in the center of the high-pressure cylinder seat 5. A high-pressure outlet 21 connected to the high-pressure one-way valve 20 is provided on the side of the high-pressure cylinder seat 5. The fourth-stage cylinder 19 is connected to the high-pressure outlet 21 in one direction through the high-pressure one-way valve 20. A third-stage piston 8 is installed at the extended end of the fourth-stage cylinder liner 7. That is, the extended end of the fourth-stage cylinder liner 7 is inserted into the tail of the third-stage piston 8 for sealing and fixing. A channel connected to the fourth-stage cylinder 19 is provided at the axis of the third-stage piston 8.
[0051] A third-stage inner cylinder liner 9 extends vertically downward from the middle of the high-pressure cylinder seat 5, and a fourth-stage cylinder liner 7 is located in the center of the third-stage inner cylinder liner 9 and is coaxial with it, so that a first-stage cooling chamber 10 is formed between the fourth-stage cylinder liner 7 and the third-stage inner cylinder liner 9. The first-stage cooling chamber 10 dissipates heat from the third-stage cylinder 27 and the fourth-stage cylinder 19. The first-stage cylinder liner 12 is located on the cylinder block surface and can directly dissipate heat from the outside to the first-stage cylinder 28. A water outlet 37 communicating with the first-stage cooling chamber 10 is provided on the high-pressure cylinder seat 5. The extended end of the third-stage inner cylinder liner 9 is sealed and fitted on the outer side of the tail of the third-stage piston 8, and the outer diameter of the third-stage inner cylinder liner 9 is smaller than the head diameter of the third-stage piston 8.
[0052] Reference Figure 1 , Figure 3 and Figure 4The bottom of the first-stage cylinder seat 14 is fixedly connected to the second-stage connecting seat 15. The second-stage connecting seat 15 is sealed and fitted inside the second-stage cooling chamber sleeve 13 and fixed. The second-stage cylinder liner 16 is coaxially fitted inside the second-stage cooling chamber sleeve 13. The first-stage piston 22, the first-stage connecting seat 6, the second-stage connecting seat 15, and the first-stage cylinder seat 14 are all annular. The lower and upper ends of the second-stage cylinder liner 16 are respectively fixedly sealed and fitted into the annular openings of the first-stage connecting seat 6 and the second-stage connecting seat 15, so that a second-stage cooling chamber sleeve 13 and the second-stage cylinder liner 16 form a two-stage cooling chamber sleeve. The first-stage cooling chamber 17 is provided, and the side of the first-stage connecting seat 6 is provided with an inlet 38 that communicates with the second-stage cooling chamber 17. The second-stage cylinder 26 is cooled through the second-stage cooling chamber 17. A delivery pipe 11 is connected between the high-pressure cylinder seat 5 and the first-stage connecting seat 6. The first-stage cooling chamber 10 and the second-stage cooling chamber 17 are connected through the delivery pipe 11, so that the outlet 37 and the inlet 38 are connected to an external cold source, so that the cooling medium circulates between the two cooling chambers and the external cold source, thereby achieving the purpose of cooling the pump body.
[0053] A first-stage piston 22 is slidably mounted inside the first-stage cylinder liner 12. The first-stage piston 22 is slidably sealed to the outside of the third-stage inner cylinder liner 9. A second-stage piston 23 is slidably mounted inside the second-stage cylinder liner 16. The lower end of the second-stage piston 23 is hinged to the upper end of the connecting rod 4. A piston rod 24 is connected between the lower end of the fourth-stage piston 18 and the middle of the upper end of the second-stage piston 23. A third-stage outer cylinder liner 25 is connected between the first-stage piston 22 and the second-stage piston 23, thereby assembling the first-stage piston 22, the second-stage piston 23 and the fourth-stage piston 18 into one unit.
[0054] Reference Figures 1-4 The head of the third-stage piston 8 extends into the annular opening of the first-stage cylinder seat 14, and the diameter of the head of the third-stage piston 8 is smaller than the diameter of the annular opening of the first-stage cylinder seat 14, so as to reserve space for the passage of the third-stage outer cylinder liner 25. This allows the upper end of the third-stage outer cylinder liner 25 to be slidably sealed onto the outside of the third-stage piston 8, so that the second-stage cylinder liner 16, the second-stage piston 23, and the third-stage piston 8 together constitute the second-stage cylinder 26. Furthermore, it creates a third-stage cylinder between the third-stage outer cylinder liner 25 and the third-stage inner cylinder liner 9. Cylinder 27, and the third-stage outer cylinder liner 25 is slidably sealed within the annulus of the first-stage cylinder seat 14 to form the first-stage cylinder 28 with the first-stage piston 22, the first-stage cylinder seat 14 and the first-stage cylinder liner 12; the outer diameter of the third-stage outer cylinder liner 25 is smaller than the inner diameter of the second-stage cylinder liner 16 so that an intake passage 29 is formed between the third-stage outer cylinder liner 25 and the second-stage cylinder liner 16, and the end of the third-stage outer cylinder liner 25 near the second-stage piston 23 is provided with a vent 30 that communicates with the intake passage 29.
[0055] The first-stage cylinder seat 14 is equipped with an air inlet 31, a first-stage one-way valve 32, and a second-stage one-way valve 33. The first-stage one-way valve 32 connects the air inlet 31 to the first-stage cylinder 28 in one direction, and the second-stage one-way valve 33 and the air hole 30 on the third-stage outer cylinder liner 25 connect the first-stage cylinder 28 to the second-stage cylinder 26 in one direction. The third-stage piston 8 is equipped with a third-stage one-way valve 34, which connects the second-stage cylinder 26 and the third-stage cylinder 27 in one direction. The fourth-stage piston 18 is equipped with a fourth-stage one-way valve 35, which connects the third-stage cylinder 27 and the fourth-stage cylinder 19 in one direction. The high-pressure cylinder seat 5 is equipped with a breather hole 36, which allows air to enter and exit the cylinder between the top of the first-stage piston 22 and the high-pressure cylinder seat 5, ensuring the normal operation of the first-stage cylinder 28.
[0056] In operation, the crankshaft 3 is driven to rotate by the motor 2. The crankshaft 3 pushes and pulls the second-stage piston 23 up and down via the connecting rod 4. The first-stage piston 22 and the fourth-stage piston 18 also move synchronously and in the same direction as the second-stage piston 23. When the crankshaft 3 pushes up, the second-stage cylinder 26 and the fourth-stage cylinder 19 compress synchronously and in the same direction, reducing their volume. At the same time, the first-stage cylinder 28 and the third-stage cylinder 27 expand synchronously in the opposite direction, increasing their volume. Specifically, when the volume of the first-stage cylinder 28 increases, external gas enters through the air inlet 31. When the volume of the first-stage cylinder 28 and the second-stage cylinder 26 decreases, the gas in the second-stage cylinder 26 enters the third-stage cylinder 27 through the three-stage one-way valve 34. When the volume of the fourth-stage cylinder 19 decreases, the gas in the fourth-stage cylinder 19 is discharged through the high-pressure outlet 21. When the volume of the first-stage cylinder 28 decreases, the gas in the first-stage cylinder 28 enters the second-stage cylinder 26 through the two-stage one-way valve 33. When the volume of the third-stage cylinder 27 decreases, the gas in the third-stage cylinder 27 enters the fourth-stage cylinder 19 through the four-stage one-way valve 35.
[0057] The high-pressure pump provided in this embodiment can achieve synchronous operation of four cylinders, which greatly improves the compression ratio and thus effectively increases the pump body's exhaust volume to meet the needs of high-pressure transmission and processing. Furthermore, the pistons of the four cylinders of this pump body are coaxial, which can ensure the balance of tension and pressure on the crankshaft 3, making it efficient and stable in operation.
[0058] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A large-displacement coaxial four-stage high-pressure pump, characterized in that, include: The cylinder body has four cylinders coaxially arranged inside. The piston of one of the cylinders is fixed inside the cylinder body, while the pistons of the other three cylinders are assembled as a whole. By driving the three pistons assembled as a whole to slide synchronously and in the same direction inside the cylinder body, two of the cylinders can be compressed synchronously and in the same direction to reduce their volume, while the other two cylinders expand synchronously in the opposite direction to increase their volume. A crankcase is installed at one end of the cylinder block, and a motor is installed on one side of the crankcase to drive the crankshaft inside the crankcase to rotate. The crankshaft inside the crankcase is connected to the piston inside the cylinder via a connecting rod, and the two ends of the connecting rod are respectively hinged to the crankshaft and the piston inside the cylinder. One end of the cylinder body is equipped with a high-pressure cylinder seat, and the other end is equipped with a primary connecting seat, and the primary connecting seat is fixed to the crankcase. A fourth-stage cylinder liner extends from the middle of the high-pressure cylinder seat to the other end of the cylinder body. The extended end of the fourth-stage cylinder liner is fitted with a third-stage piston, that is, the extended end of the fourth-stage cylinder liner is inserted into the tail of the third-stage piston for sealing and fixing. The third-stage piston has a channel at its shaft center that communicates with the cavity of the fourth-stage cylinder liner. The high-pressure cylinder seat also extends a three-stage inner cylinder liner to the other end of the cylinder body, and the fourth-stage cylinder liner is located in the center of the three-stage inner cylinder liner, so that a first-stage cooling chamber is formed between the fourth-stage cylinder liner and the three-stage inner cylinder liner. The extended end sealing sleeve of the third-stage inner cylinder liner is provided on the outer side of the tail of the third-stage piston, and the outer diameter of the third-stage inner cylinder liner is smaller than the head diameter of the third-stage piston. The cylinder block is composed of a primary cylinder liner and a secondary cooling chamber sleeve, and the primary cylinder liner and the secondary cooling chamber sleeve are connected by a primary cylinder seat. The end of the first-stage cylinder liner furthest from the first-stage cylinder seat is connected to the high-pressure cylinder seat, and the end of the second-stage cooling chamber sleeve furthest from the first-stage cylinder seat is connected to the first-stage connecting seat. The end of the primary cylinder seat facing the secondary cooling chamber sleeve is connected to a secondary connecting seat; The secondary cooling chamber sleeve is coaxially fitted with a secondary cylinder liner, so that a secondary cooling chamber is formed between the secondary cooling chamber sleeve and the secondary cylinder liner; The sliding seal of the fourth-stage cylinder liner is fitted with a fourth-stage piston to form a fourth-stage cylinder with the high-pressure cylinder seat. The high-pressure cylinder seat is provided with a high-pressure one-way valve and a high-pressure outlet. The high-pressure one-way valve enables one-way communication between the fourth-stage cylinder and the high-pressure outlet. A first-stage piston is slidably disposed inside the first-stage cylinder liner, and the first-stage piston is slidably sealed to the outside of the third-stage inner cylinder liner; a second-stage piston is slidably disposed inside the second-stage cylinder liner. The end of the secondary piston facing the crankcase is hinged to the end of the connecting rod. A piston rod is connected between the middle of the fourth-stage piston and the second-stage piston; The first-stage piston, first-stage connecting seat, second-stage connecting seat, and first-stage cylinder seat are all annular, so that the two ends of the second-stage cylinder liner are respectively fixedly sealed and fitted into the annular openings of the first-stage connecting seat and the second-stage connecting seat, and the head of the third-stage piston extends into the annular opening of the first-stage cylinder seat, and the diameter of the head of the third-stage piston is smaller than the diameter of the annular opening of the first-stage cylinder seat. A third-stage outer cylinder liner is connected between the first-stage piston and the second-stage piston. The end of the third-stage outer cylinder liner that connects with the first-stage piston is slidably sealed to the outside of the third-stage piston, so that the second-stage cylinder liner, the second-stage piston and the third-stage piston together constitute the second-stage cylinder. The third-stage outer cylinder liner and the third-stage inner cylinder liner also form a third-stage cylinder. At the same time, the third-stage outer cylinder liner is slidably sealed to the annular opening of the first-stage cylinder seat to form the first-stage cylinder. The outer diameter of the third-stage outer cylinder liner is smaller than the inner diameter of the second-stage cylinder liner, so that an intake passage is formed between the third-stage outer cylinder liner and the second-stage cylinder liner, and the end of the third-stage outer cylinder liner near the second-stage piston is provided with an air hole that communicates with the intake passage.
2. The large-displacement coaxial four-stage high-pressure pump according to claim 1, characterized in that, The first-stage cylinder seat is equipped with an air inlet, a first-stage check valve, and a second-stage check valve. The first-stage one-way valve enables the air inlet to be connected to the first-stage cylinder in one direction. The two-stage one-way valve enables the first-stage cylinder to be unidirectionally connected to the second-stage cylinder. The third-stage piston is equipped with a three-stage one-way valve, and the fourth-stage piston is equipped with a four-stage one-way valve. The three-stage one-way valve enables one-way communication between the second-stage cylinder and the third-stage cylinder, and the four-stage one-way valve enables one-way communication between the third-stage cylinder and the fourth-stage cylinder. The high-pressure cylinder seat is provided with a breather hole, through which air is supplied to the cylinder body between the first-stage piston and the high-pressure cylinder seat for intake and exhaust.
3. The large-displacement coaxial four-stage high-pressure pump according to claim 2, characterized in that, The high-pressure cylinder base is also provided with a water outlet that connects to the primary cooling chamber. The primary connecting seat is provided with a water inlet that connects to the secondary cooling chamber; A delivery pipe is connected between the high-pressure cylinder seat and the first-stage connecting seat. The delivery pipe connects the first-stage cooling chamber and the second-stage cooling chamber, so that the outlet and inlet are connected to an external cold source, allowing the cooling medium to circulate between the cooling chamber and the external cold source.