A swash plate piston type hydraulic pump

Abstract

The present application relates to the field of hydraulic pump, especially to a swash plate piston type hydraulic pump. The swash plate piston type hydraulic pump comprises a shell and a plunger, the shell is provided with a liquid outlet channel communicated with the plunger cavity, and a liquid outlet check valve is further arranged in the liquid outlet channel; the shell is further provided with a liquid inlet channel communicated with the plunger cavity; the plunger comprises a solid section, the solid section cooperates with the plunger cavity to separate the plunger cavity and the oil cavity, the two ends of the liquid inlet channel are respectively communicated with the oil cavity and the plunger cavity, and a liquid inlet check valve is arranged in the liquid inlet channel. By arranging the liquid inlet channel communicated with the plunger cavity on the shell, the oil inlet position is changed from the plunger to the shell, the solid section separates the oil cavity and the plunger cavity, and the problem that the existing technology opens a through hole on the plunger for oil inlet, the gap exists between the plunger and the main shaft due to the sliding fit, and the internal leakage easily occurs on the swash plate surface to cause the oil loss or even the problem that the oil cannot be pumped is solved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic pumps, and more particularly to a swashplate piston hydraulic pump. Background Technology

[0002] Hydraulic transmission technology boasts advantages such as high power density, convenient control, fast response speed, and precise displacement / force control, and is widely used in various sectors of national economic development, including transportation, engineering construction, and resource extraction. The increasing demand for green, lightweight, and electrified high-end equipment such as aircraft, legged robots, mobile machinery, and deep-sea submersibles is driving the development of hydraulic pumps towards miniaturization and higher pressure.

[0003] Chinese invention patent application CN109798231A discloses a swashplate miniature piston pump, which includes a swashplate (i.e., main shaft), a slipper, a return plate, a return rod, a piston, and a piston cylinder. The swashplate and slipper are in sliding engagement. One end of the piston is spherical and engages with a spherical cavity on the slipper, while the other end engages with the piston cylinder. To facilitate hydraulic oil transfer, a waist-shaped hole is provided on the swashplate, and a through hole is provided at the piston axis position, communicating with the piston cavity in the piston cylinder. When the slipper aligns with the waist-shaped hole, it can draw in oil. When the slipper is misaligned with the waist-shaped hole, the piston compresses the volume of the piston cavity, allowing the oil in the piston cavity to flow through the flow channel to the outlet, thus enabling continuous operation of the piston pump.

[0004] In the above technical solution, the oil intake of the plunger pump is achieved by drilling holes in the plunger and using the cooperation of the slipper and the spindle swashplate. However, the spindle swashplate and the slipper are in sliding fit, so a gap will be generated between the slipper and the spindle swashplate. When the plunger pumps oil outward, some of the oil in the plunger cavity will escape outward along the gap between the slipper and the spindle swashplate, resulting in internal leakage. This causes the plunger to pump less oil per round trip or even fail to pump oil at all. Summary of the Invention

[0005] The purpose of this invention is to provide a swashplate plunger hydraulic pump to solve the problem in the prior art where oil is introduced through a hole in the plunger, and the plunger and the spindle have a sliding fit with a gap, which can easily lead to internal leakage on the swashplate surface, resulting in oil loss or even failure to pump oil.

[0006] To achieve the above objectives, the swashplate piston hydraulic pump of this invention adopts the following technical solution:

[0007] A swashplate plunger hydraulic pump includes a housing and a plunger. The housing has an oil inlet and an oil chamber and a plunger chamber inside the housing. One end of the plunger is inserted into the plunger chamber and used to change the volume of the plunger chamber. The housing has an outlet channel communicating with the plunger chamber and an outlet check valve is installed in the outlet channel. The plunger includes a solid section for preventing communication between the plunger chamber and the oil chamber. The housing has an inlet channel with its inlet port communicating with the oil chamber and its outlet port communicating with the plunger chamber. An inlet check valve is installed in the inlet channel.

[0008] The beneficial effects of the above technical solution are as follows: This invention improves upon existing swashplate plunger hydraulic pumps by providing an inlet channel connecting the plunger cavity to the housing, thus changing the oil inlet position from the plunger to the housing. This eliminates the need for a through hole in the plunger at the axis, allowing the plunger to include a solid section that separates the oil cavity from the plunger cavity. This means that during the reciprocating motion of the plunger, oil is drawn directly from the oil cavity without needing to pass through the through hole in the plunger. Furthermore, by providing a one-way valve, the plunger cavity can be selectively connected to either the inlet or outlet channel, allowing the oil to flow unidirectionally within both channels. This solves the problem in existing technologies where a through hole is opened in the plunger for oil inlet, and the sliding fit between the plunger and the spindle creates a gap, leading to internal leakage on the swashplate surface, resulting in oil loss or even pumping failure.

[0009] Furthermore, the housing is provided with a one-way valve mounting hole and an oil suction hole communicating with the oil chamber. The oil suction hole constitutes the inlet of the liquid inlet channel. The one-way valve mounting hole is arranged facing the outside of the housing, and a sealing element is installed in the one-way valve mounting hole.

[0010] The advantages of the above technical solution are: it is easy to install, and the sealing component can be used to seal the one-way valve mounting hole after installation to prevent oil leakage.

[0011] Furthermore, the sealing member is provided with an operating hole extending inward to the inside of the sealing member.

[0012] The advantages of the above technical solution are that it facilitates the installation of the sealing components and also facilitates the reduction of the weight of the device.

[0013] Furthermore, the housing is provided with a tubular structure that protrudes relative to the surface of the housing, and the one-way valve mounting hole is provided inside the tubular structure.

[0014] The advantages of the above technical solution are: it facilitates the setting of the one-way valve mounting hole and avoids the outer diameter of the housing being too large.

[0015] Furthermore, at least four tube structures are uniformly arranged on the shell, and the number of tube structures is the same as the number of plunger cavities and corresponds one-to-one. The axis of the tube structure is a tangent to the same circle.

[0016] The advantages of the above technical solution are: compact structure, high pumping efficiency, and uniform distribution, which makes the swashplate plunger hydraulic pump pump oil more evenly during operation.

[0017] Furthermore, the swashplate piston hydraulic pump includes a slipper, the slipper comprising a slipper return body and a slipper support body connected by threads, with a ball socket formed between the slipper return body and the slipper support body to receive the end of the piston.

[0018] The beneficial effects of the above technical solution are as follows: the size of the ball socket can be changed by the threaded sliding shoe return body and sliding shoe support body. When the plunger and ball socket wear and a gap appears between the plunger and ball socket, the gap between the end of the ball socket and the plunger can be reduced by adjusting the thread, thereby avoiding the impact and vibration caused by the existence of the gap during the reciprocating motion of the plunger.

[0019] Furthermore, the return body and the support body of the skid are provided with an anti-loosening structure to prevent the return body and the support body of the skid from becoming loose.

[0020] The beneficial effect of the above technical solution is that it avoids loosening between the skate return body and the skate support body during the movement.

[0021] Furthermore, the return body of the slipper is provided with a circumferential array of anti-rotation grooves, and the slipper support is provided with a pin hole, in which a pin is provided. The pin cooperates with the anti-rotation groove to prevent rotation.

[0022] The advantages of the above technical solution are: simple structure, and the ability to use the spindle to limit the pin and prevent the pin from coming out.

[0023] Furthermore, the swashplate plunger hydraulic pump also includes a main shaft, a slipper, and a return plate. The end face of the main shaft is provided with a threaded hole. The return plate and the slipper are limited by a fixing bolt fitted in the threaded hole. The fixing bolt passes through the return plate and is threadedly engaged with the threaded hole. The bolt head of the fixing bolt is used to engage with the stop of the return plate.

[0024] The advantages of the above technical solution are: the gap between the inclined end of the spindle and the slipper can be adjusted, which makes it easier to adjust the magnitude of the friction between the two, and the connection is firm, making it easier to withstand a large torque.

[0025] Furthermore, the swashplate piston hydraulic pump also includes a spindle and a slipper. The spindle includes a spindle body and a wear-resistant disc disposed on the end face of the spindle body. The wear-resistant disc and the slipper slide in contact.

[0026] The beneficial effects of the above technical solution are that the material and forming method of the wear-resistant disc can be improved separately, thereby improving the wear resistance of the wear-resistant disc and avoiding damage to the spindle. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the swashplate piston hydraulic pump in this invention;

[0028] Figure 2 for Figure 1 View from AA direction;

[0029] Figure 3 This is a schematic diagram of the fit between the slipper and the plunger in Embodiment 1 of the swashplate plunger hydraulic pump of the present invention;

[0030] Figure 4 This is a schematic diagram of the piston structure in Embodiment 1 of the swashplate piston hydraulic pump of the present invention;

[0031] Figure 5 This is a rear view of the slipper in Embodiment 1 of the swashplate piston hydraulic pump of the present invention;

[0032] Figure 6 This is a schematic diagram of the slipper return body in Embodiment 1 of the swashplate piston hydraulic pump of the present invention;

[0033] Figure 7 This is a side view of the slipper return body in Embodiment 1 of the swashplate piston hydraulic pump of the present invention;

[0034] Figure 8 This is a schematic diagram of the cylinder block in Embodiment 1 of the swashplate piston hydraulic pump of the present invention;

[0035] Figure 9 This is a side view of the cylinder block in Embodiment 1 of the swashplate piston hydraulic pump of the present invention;

[0036] Figure 10 This is a schematic diagram of the housing body in Embodiment 1 of the swashplate plunger hydraulic pump of the present invention.

[0037] In the diagram: 11. Main spindle body; 12. Wear-resistant disc; 13. Fixing screw; 21. Slipper support body; 22. Slipper return body; 221. Anti-rotation groove; 23. Pin; 24. Lubricating oil passage; 31. Housing body; 311. Oil inlet; 32. Cylinder; 321. Plunger chamber; 322. Liquid inlet; 324. One-way valve mounting hole; 33. Valve seat; 34. Plug; 35. Inlet one-way valve; 36. Outlet one-way valve; 4. Return disc; 5. Plunger; 51. Spherical end; 52. Cylindrical end; 6. End cap; 71. Sealing ring; 72. Bearing; 73. Snap ring. Detailed Implementation

[0038] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0039] In Embodiment 1 of the swashplate piston hydraulic pump of the present invention:

[0040] In this embodiment, the hydraulic channel is set on the housing, the plunger is set as a closed component, and a plunger cavity connected to the hydraulic channel is provided, so that the oil flows out of the hydraulic channel after being compressed by the plunger. At the same time, the hydraulic channel includes an inlet channel and an outlet channel, and a one-way valve is provided in the inlet channel and the outlet channel, so that when the plunger moves, it can selectively connect the plunger cavity with the inlet channel or the outlet channel, thereby enabling the oil in the inlet channel to be continuously delivered to the outlet channel.

[0041] like Figure 1 As shown, the swashplate piston hydraulic pump (hereinafter referred to as the piston pump) in this embodiment includes a housing, a main shaft, slippers, a piston 5, and an end cap 6. The main shaft is rotatably mounted inside the housing via a bearing 72 and is sealed by a sealing ring 71. The housing includes a housing body 31 and a cylinder 32. The cylinder 32 is fixedly connected to the housing body 31 via a threaded section, forming an oil chamber between them. Figure 1 , Figure 9 , Figure 10 As shown, an oil inlet 311 is provided on the housing body 31, and a plunger cavity 321 and a hydraulic channel are provided on the cylinder body 32. The plunger cavity 321 and the hydraulic channel are interconnected. As the plunger 5 reciprocates within the plunger cavity 321, it can compress the plunger cavity 321, thereby driving the oil to flow within the plunger cavity 321. The end cap 6 is fixedly connected to the cylinder body 32, and the end cap 6 is provided with an oil outlet that communicates with the outlet of the hydraulic channel on the cylinder body 32. That is to say, the oil flows in from the oil inlet 311 on the housing body 31, passes through the plunger cavity 321 and the hydraulic channel, and then flows out from the oil outlet of the end cap 6, completing the directional movement of the oil.

[0042] The spindle includes a spindle body 11 and a wear-resistant disc 12. The spindle body 11 is generally cylindrical, with a stepped section protruding radially from its end face. A retaining spring 73 is also provided on the end of the spindle body 11 extending out of the housing to limit the position of the spindle and prevent relative movement between the spindle and the housing. The stepped section of the spindle body 11 forms a beveled end, with a threaded hole for mounting a fixing bolt. The wear-resistant disc 12 has an opening in the middle for a fixing screw 13 to pass through. Multiple slippers are also in contact with the end face of the wear-resistant disc 12 away from the spindle body 11. In this embodiment, four slippers are provided, and the four slippers are kept in a constant relative position by a return disc 4. Specifically, the return disc 4 has a through hole on the axis for the fixing bolt to pass through and engage with the bolt head. Four slipper through holes for the slippers to pass through and be fixed are also evenly distributed on the surface of the return disc 4. In other words, the fixing bolts limit the return plate 4 to the corresponding position, and the return plate 4 fixes the slipper to the corresponding position through the slipper hole.

[0043] like Figure 4 As shown, the plunger 5 is a solid section, comprising a spherical end 51 at one end and a cylindrical end 52 at the other end. The diameter of the spherical end 51 is larger than the diameter of the cross-section of the cylindrical end 52. The spherical end 51 is hinged to the slipper, and the cylindrical end 52 extends into the cylinder block 32. Each slipper has the same structure; the structure of one slipper will be described using it as an example. Figure 3 As shown, the slipper includes a slipper return body 22 and a slipper support body 21 connected by threads. The slipper return body 22 and the slipper support body 21 are each provided with a spherical recess. The slipper return body 22 and the slipper support body 21 cooperate to form a ball socket located between them to accommodate the spherical end 51 of the plunger 5. The plunger pump also includes an anti-loosening structure located on the slipper return body 22 and the slipper support body 21 to prevent them from becoming loose. Specifically, as shown... Figure 6 and Figure 7 As shown, in this embodiment, the return body 22 of the slipper is provided with a circumferential array of anti-rotation grooves 221, such as... Figure 3 and Figure 5 As shown, the slipper support 21 is provided with a pin hole through which the pin 23 passes and a pin 23 is inserted. When the slipper return body 22 and the slipper support 21 move into place, the pin 23 cooperates with the anti-rotation groove 221 to prevent rotation. In addition, a cross-shaped lubrication oil channel 24 is provided on the end face of the slipper support 21 that contacts the wear-resistant disc 12. Oil can enter between the slipper support 21 and the wear-resistant disc 12 through the lubrication oil channel 24, reducing the friction between the two and carrying away the heat generated by friction.

[0044] The cylinder body 32 is provided with a plunger cavity 321 for the cylindrical end 52 of the plunger 5 to be inserted. The hydraulic channel includes an inlet channel located upstream of the plunger cavity 321 and an outlet channel located downstream of the plunger cavity 321. The inlet 322 of the hydraulic channel is located on the end of the cylinder body 32 facing the oil cavity and communicating with the oil cavity, that is, the inlet 322 is located in the inlet channel, and the inlet 322 on the cylinder body 32 is parallel to the axis of the plunger cavity 321. In this embodiment, the inlet 322 is an oil suction hole. The outlet channel is provided with an outlet for pumping out oil. Valves for unidirectional flow of oil from the inlet 322 to the outlet are respectively provided in the inlet channel and the outlet channel of the hydraulic channel. In this embodiment, the valve is a ball valve pushed by a spring. The structure of the ball valve is prior art and will not be described in detail here.

[0045] like Figure 2 , Figure 8 and Figure 9 As shown, the cylinder body 32 also has four protruding tubular structures relative to the surface of the shell. The number of tubular structures is the same as the number of plunger cavities 321, and their positions correspond one-to-one. The axes of the tubular structures are tangents to the same circle. A one-way valve mounting hole 324 is provided within the tubular structure, connecting to the hydraulic passage. The one-way valve mounting hole 324 communicates with the ball valve upstream of the plunger cavity 321, facilitating the one-way valve in the inlet passage and allowing for sealing of the mounting port using a sealing component after the ball valve is installed. In this embodiment, the sealing component includes a valve seat 33 and a screw plug 34. Both the valve seat 33 and the screw plug 34 have operating holes, which facilitate installation and reduce the weight of the sealing component. The sealing component ensures that the hydraulic passage is connected to the external hydraulic passage of the cylinder body 32, specifically the inlet 322 and outlet.

[0046] During the operation of the plunger pump, the main shaft rotates. As the main shaft rotates, the wear-resistant disc 12 oscillates around its center, causing the slipper at the contact point with the wear-resistant disc 12 to slide relative to it. The slipper reciprocates along its axial direction, thus driving the plunger 5 to reciprocate. When the plunger 5 moves outward, a negative pressure is created in the plunger cavity 321, causing the inlet check valve 35 in the inlet channel to open, allowing oil to enter the inlet channel from the oil chamber, completing the oil intake. When the plunger 5 moves inward, the space within the plunger cavity 321 is compressed, causing the outlet check valve 36 in the outlet channel to open, allowing liquid to be squeezed out of the outlet channel, completing the pumping process.

[0047] In Embodiment 2 of the swashplate plunger hydraulic pump of the present invention: Regarding the arrangement of the spindle, this embodiment proposes a new arrangement. Unlike Embodiment 1, in this embodiment, the spindle includes the spindle body and no longer has a wear-resistant disc. At this time, the end face of the spindle body is in direct contact with the slipper.

[0048] In Embodiment 3 of the swashplate piston hydraulic pump of the present invention: Regarding the arrangement of the return plate, this embodiment proposes a new arrangement. Unlike Embodiment 1, in this embodiment, the main shaft and the return plate are no longer connected by fixing bolts, but are pressed against the main shaft by an elastic element located on the cylinder body.

[0049] In Embodiment 4 of the swashplate piston hydraulic pump of the present invention: Regarding the anti-loosening structure, this embodiment proposes a new arrangement. Unlike Embodiment 1, the anti-loosening structure in this embodiment is an adhesive tape that bonds the slipper return body and the slipper support body together. Of course, in other embodiments, the anti-loosening structure may not be required.

[0050] In Embodiment 5 of the swashplate plunger hydraulic pump of the present invention: Regarding the arrangement of the slipper, this embodiment proposes a new arrangement. Unlike Embodiment 1, in this embodiment, the slipper is no longer a split structure but a one-piece structure with a spherical cavity.

[0051] In Embodiment 6 of the swashplate plunger hydraulic pump of the present invention: Regarding the arrangement of the pipe structure, this embodiment proposes a new arrangement. Unlike Embodiment 1, this embodiment no longer sets four evenly distributed pipe structures, but sets five pipe structures. Of course, in other embodiments, the number of pipe structures can be less than four, such as three.

[0052] In Embodiment 7 of the swashplate plunger hydraulic pump of the present invention: Regarding the arrangement of the pipe structure, this embodiment proposes a new arrangement. Unlike Embodiment 1, in this embodiment, the number and position of the pipe structure and the plunger cavity are not one-to-one, and two pipe structures correspond to one plunger cavity.

[0053] In Embodiment 8 of the swashplate piston hydraulic pump of the present invention: Regarding the setting of the check valve mounting hole, this embodiment proposes a new arrangement. Unlike Embodiment 1, in this embodiment, the check valve mounting hole is no longer set in the pipe structure, but is set on the cylinder.

[0054] In Embodiment 9 of the swashplate plunger hydraulic pump of the present invention: Regarding the arrangement of the sealing member, this embodiment proposes a new arrangement. Unlike Embodiment 1, the sealing member in this embodiment no longer has an operating hole, but instead has a force-applying hexagonal prism protruding from the sealing member.

[0055] In Embodiment 10 of the swashplate plunger hydraulic pump of the present invention: Regarding the housing arrangement, this embodiment proposes a new arrangement. Unlike Embodiment 1, this embodiment no longer provides a check valve mounting hole, but instead provides a check valve at the junction of the cylinder and the housing body.

[0056] In Embodiment 11 of the swashplate plunger hydraulic pump of the present invention: Regarding the arrangement of the plunger, this embodiment proposes a new arrangement. Unlike Embodiment 1, in this embodiment, the plunger is no longer entirely a solid section, but also includes a hollow section, with the solid and hollow sections arranged alternately.

[0057] In Embodiment 12 of the swashplate plunger hydraulic pump of the present invention: Regarding the arrangement of the spindle, this embodiment proposes a new arrangement. Unlike Embodiment 1, in this embodiment, the housing is no longer divided into a housing body and a cylinder connected by a threaded section, but is divided into a housing body and an end cap disposed on the housing body.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A swashplate plunger hydraulic pump, characterized in that: The system includes a spindle, slippers, end caps, a housing, and a plunger (5). The housing comprises a housing body and a cylinder body, which together form an oil chamber. The housing body has an oil inlet, and the cylinder body has a plunger chamber and a hydraulic channel. One end of the plunger (5) is inserted into the plunger chamber (321) and used to change the volume of the plunger chamber (321). The end cap is connected to the cylinder body and has an oil outlet that communicates with the outlet of the hydraulic channel. During use, oil flows into the oil chamber from the oil inlet on the housing body, passes through the plunger chamber and the hydraulic channel, and then flows out from the oil outlet on the end cap. The hydraulic channel includes... The inlet and outlet channels are connected. The inlet of the inlet channel is connected to the oil chamber and the outlet is connected to the plunger chamber. The inlet channel is equipped with an inlet check valve. The outlet channel is connected to the plunger chamber and is equipped with an outlet check valve. The plunger (5) includes a solid section for preventing the plunger chamber (321) and the oil chamber from communicating. The spindle includes the spindle body and the wear-resistant disc. The slipper includes the slipper return body and the slipper support body. The end face of the slipper support body that contacts the wear-resistant disc is provided with a lubricating oil channel. When in use, the spindle rotates and the oil flowing into the oil chamber enters the space between the slipper support body and the wear-resistant disc through the lubricating oil channel.

2. The swashplate piston hydraulic pump according to claim 1, characterized in that: The cylinder body is provided with a one-way valve mounting hole (324) and an oil suction hole that communicates with the oil chamber. The oil suction hole forms the inlet of the liquid inlet channel. The one-way valve mounting hole (324) is arranged facing the outside of the cylinder body, and a sealing component is installed in the one-way valve mounting hole (324).

3. The swashplate plunger hydraulic pump according to claim 2, characterized in that: The sealing element is provided with an operating hole extending inward to the inside of the sealing element.

4. The swashplate plunger hydraulic pump according to claim 2 or 3, characterized in that: The cylinder body is provided with a tube structure that protrudes relative to the surface of the cylinder body, and the tube structure is provided with the one-way valve mounting hole (324).

5. The swashplate piston hydraulic pump according to claim 4, characterized in that: The cylinder body is uniformly provided with at least four tube structures. The number of tube structures is the same as the number of plunger cavities (321) and they correspond one-to-one. The axis of each tube structure is a tangent to the same circle.

6. The swashplate piston hydraulic pump according to any one of claims 1-3, characterized in that: The return body (22) and the support body (21) are threaded together, and a ball socket is formed between the return body (22) and the support body (21) to accommodate the end of the plunger (5).

7. The swashplate piston hydraulic pump according to claim 6, characterized in that: The return body (22) and the support body (21) of the slipper are provided with anti-loosening structures to prevent the return body (22) and the support body (21) of the slipper from becoming loose.

8. The swashplate piston hydraulic pump according to claim 7, characterized in that: The return body (22) of the slipper is provided with a circular array of anti-rotation grooves (221), and the slipper support (21) is provided with a pin hole, and a pin is provided in the pin hole. The pin cooperates with the anti-rotation groove (221) to prevent rotation.

9. The swashplate piston hydraulic pump according to any one of claims 1-3, characterized in that: The swashplate plunger hydraulic pump also includes a return plate (4). A threaded hole is provided on the end face of the main shaft. The return plate (4) and the slipper are limited by a fixing bolt installed in the threaded hole. The fixing bolt passes through the return plate (4) and is threadedly engaged with the threaded hole. The bolt head of the fixing bolt is used to stop the return plate (4).

10. The swashplate piston hydraulic pump according to any one of claims 1-3, characterized in that: The cylinder block and the housing body are fixedly connected by a threaded section.

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