Double-acting curve plunger pump supported by balls

Abstract

The invention provides a double-acting curve plunger pump supported by balls, the plunger pump comprises a pump shell assembly and a pump core assembly, the pump core assembly is coaxially arranged in the pump shell assembly along the axis, the pump core assembly comprises a rotor structure and a stator structure, the pump shell assembly is matched with the pump core assembly to achieve flow distribution on the inner side and the outer side of the plunger pump. According to the axial plunger pump, the so-called ceiling effect formed by increasing the rotating speed of a traditional axial plunger pump can be broken through, and the power density is increased.

Description

Technical Field

[0001] This invention belongs to the field of fluid machinery technology and relates to a ball-bearing double-acting curved piston pump, which is suitable for working conditions where fuel oil or hydraulic oil is used as the working medium. Background Technology

[0002] A pump is an energy conversion device that transforms mechanical energy into fluid pressure energy, typically used to output high-pressure fluids. Traditional pumps, such as piston, vane, gear, and screw pumps, rely primarily on sliding friction in their mechanical structure during operation, resulting in significant frictional energy loss. Furthermore, the complex shapes of their components lead to high manufacturing costs. Traditional piston pumps, using swashplates and slippers, further increase frictional losses, leading to low efficiency. They also suffer from poor self-priming capabilities and significant churning losses, making them unsuitable for high-speed applications. Therefore, there is an urgent need to overcome the so-called "ceiling effect" of increasing the rotational speed of traditional axial piston pumps. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0004] To address this, the present invention provides a ball-supported double-acting curved piston pump, which can overcome the so-called "ceiling effect" caused by increasing the rotational speed of traditional axial piston pumps and improve power density.

[0005] The technical solution of the present invention is as follows:

[0006] This invention provides a ball-supported double-acting curved piston pump, the piston pump comprising:

[0007] A pump housing assembly, comprising an upper end cover, a pump housing, and a rear end cover arranged coaxially along an axis, the upper end cover, the pump housing, and the rear end cover being fixedly connected to form a pump housing assembly, the pump housing being provided with a high-pressure flow channel and a high-pressure outlet;

[0008] A pump core assembly is coaxially arranged within the pump housing assembly. The pump core assembly includes a rotor structure and a stator structure. The rotor structure includes a distribution shaft, cams, balls, a double-acting plunger, a distribution sleeve, and a synchronizing pin. The stator structure includes a cylinder block, a plunger sleeve, and a plunger sleeve baffle. The distribution shaft and cam transmit torque through a transmission flat structure, and their axial movement is restricted by bearings and the distribution shaft. The distribution sleeve rotates synchronously with the cam and distribution shaft via the synchronizing pin, jointly completing the distribution function. The double-acting plunger, plunger sleeve, and cylinder block form a closed annular space, i.e., a plunger cavity. Due to the presence of the stator structure, when the rotor structure rotates, the double-acting plunger reciprocates axially under the action of the cams at both ends, causing the plunger cavity to simultaneously expand and contract, completing the expansion and compression of the fluid medium.

[0009] The pump housing assembly and the pump core assembly work together to achieve flow distribution on both the inner and outer sides of the plunger pump.

[0010] Furthermore, the cam is an end-face cam structure and adopts a double-peak double-valley profile. A ball groove with the same undulation as the profile is provided in the middle part of the profile. In the pump core, there are two cams with the same structure, but the peaks and valleys are distributed correspondingly on the distribution shaft. The cam undertakes the axial reciprocating motion of the double-acting plunger.

[0011] Furthermore, the double-acting plunger is designed to be thicker in the middle and thinner at both ends, with hollow ends. Multiple pressure-equalizing grooves and flow holes are symmetrically arranged on the outer diameter surfaces at both ends of the double-acting plunger. Ball sockets are located at both ends. At the larger diameter in the middle, the hollow inner diameters at both ends communicate with the outer diameter of the thinner shaft on the opposite side through oblique holes. When the double-acting plunger moves to the left, the left plunger cavity becomes smaller, the fluid is compressed, and the high-pressure fluid enters the right central hole through the oblique hole, then flows out through the flow holes and pressure-equalizing grooves, forming a static pressure oil film on the right smaller diameter. The high-pressure fluid in the right central hole can also leak into the housing through the right ball socket. Due to the presence of the balls, a lubricating oil film can be formed at the balls, creating static pressure support for the balls. Simultaneously, the balls and the double-acting plunger are separated by the lubricating oil film, and the balls and cams exhibit pure rolling motion.

[0012] Furthermore, the distribution shaft is a hollow structure, and a flat keyway, a bearing mounting surface, a pressure relief hole, a distribution shaft sealing strip, a distribution window, and a bearing mounting surface are provided along the axis of the distribution shaft. The interior of the distribution shaft is a central hole. The distribution shaft integrates the functions of support and distribution into one unit. The support surfaces are distributed at both ends of the distribution shaft, and the distribution window is located in the middle of the distribution shaft. There are two sets of distribution windows, which are distributed at 90° to each other. A distribution shaft sealing strip of a certain width is distributed on both sides of the distribution window.

[0013] Furthermore, the distribution sleeve is a thin-walled sleeve structure. One side of the distribution sleeve has a pair of through holes for installing a synchronizing pin to ensure that it rotates synchronously with the cam. The other side has a pair of rectangular distribution windows to complete the distribution of high-pressure fluid. The distribution windows are symmetrically distributed, and the inner wall is subjected to symmetrical hydraulic pressure of the high-pressure fluid, which can ensure that a lubricating oil film is formed between the distribution sleeve and the cylinder.

[0014] Furthermore, the flow distribution sleeve is provided in two parts, and the flow distribution windows on the left and right sides are distributed at 90° to complete the alternating flow distribution on the left and right sides of the plunger cavity.

[0015] Furthermore, the cylinder body has a honeycomb structure, with a central hole in the middle serving as the low-pressure flow channel for the double-acting curved plunger pump. Eight through holes are arranged circumferentially around the central hole, forming a sealed space—the plunger cavity—with the plunger sleeve and the double-acting plunger. The central hole and through holes communicate through rectangular distribution windows, forming low-pressure distribution windows. The through holes communicate with the cylinder outer diameter through distribution windows, forming high-pressure distribution windows. Symmetrically distributed sleeve structures are located on the cylinder outer diameter, forming deep circular grooves with the cylinder outer diameter to create a gap seal with the distribution sleeves. The sleeve structures have the same number and size of rectangular windows distributed circumferentially with the cylinder outer diameter. When the plunger cavity is in the oil discharge stroke, the distribution windows on the distribution sleeves communicate with the high-pressure distribution windows in the cylinder body, allowing the high-pressure fluid to flow through the distribution windows on the sleeve structures to the high-pressure flow channel, thus completing the high-pressure fluid distribution.

[0016] Furthermore, the method for implementing the flow distribution on both the inner and outer sides is as follows:

[0017] During the operation of a double-acting curve piston pump, each pair of adjacent double-acting pistons is under the same working condition. For the left side of the piston chamber, when the two adjacent piston chambers on the left are in the compression stroke, the other two adjacent piston chambers symmetrically positioned on the center are also in the compression stroke. At this time, the distribution window on the distribution shaft is closed to the piston chamber, and the distribution window on the distribution sleeve is connected to the high-pressure flow channel. At the same time, the two piston chambers adjacent to the compression stroke are in the expansion stroke, and the other two piston chambers symmetrically positioned on the center are also in the expansion stroke. At this time, the distribution window on the distribution shaft is connected to the piston chamber, and the distribution window on the distribution sleeve is closed to the high-pressure flow channel. Thus, the piston chambers alternately suck and discharge oil, the low-pressure distribution window of the distribution shaft alternately communicates with the low-pressure distribution window of the cylinder block, and the high-pressure distribution window of the cylinder block alternately communicates through the high-pressure distribution window of the distribution sleeve, completing the "internal and external distribution" of the double-acting curve piston pump.

[0018] Applying the above technical solution, a ball-supported double-acting curved plunger pump is provided. This invention employs a rotating distribution shaft and distribution sleeve on both the inner and outer sides for distribution, while the cylinder body remains stationary. The double-acting piston reciprocates to draw and discharge oil, forming a motion structure of "rotating distribution on both sides + reciprocating piston suction and discharge + double-acting." Compared to a traditional transmission plunger pump, this simplifies the system structure. Specifically, the distribution shaft drives the front and rear cam guides and distribution sleeve to rotate, while the cylinder body remains stationary. The plunger and balls reciprocate axially under the action of the cam guides, causing the volume of the plunger cavities on both sides to alternately increase and decrease, realizing the expansion and compression of the fluid medium and completing the suction and discharge functions. Furthermore, this invention uses a ball hydrostatic support structure, replacing the swashplate slipper of the traditional plunger pump with a ball cam mechanism, converting the sliding friction pair into a rolling friction pair. This improves the working conditions of the friction pair, facilitates the formation of a lubricating oil film, reduces friction loss, and increases working efficiency. This invention employs a double-acting plunger and a double-peak, double-valley cam structure. One double-acting plunger is equivalent to four traditional plungers, allowing for a smaller and lighter design while maintaining the same performance parameters. This is significant for applications in aerospace, mobile machinery, and other fields requiring high power density and small size. The invention utilizes a rotating distribution shaft and distribution sleeve with a fixed distribution cylinder, ensuring the distribution pairs do not contact the cylinder, reducing wear and effectively guaranteeing long-term stable operation of the pump core. In this structure, oil is drawn in at the distribution shaft and discharged at the distribution sleeve. The pump inlet flow channel is simple and unobstructed, resulting in low flow resistance and significantly improving the pump's self-priming capability. Furthermore, the plunger only undergoes reciprocating motion, reducing the pv value limitation of centrifugal force generated by the plunger pair's rotational motion and minimizing oil churning losses, making it more suitable for high-speed applications. Attached Figure Description

[0019] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0020] Figure 1 This is a schematic diagram of a ball-supported double-acting curved plunger pump according to the present invention.

[0021] Figure 2 This is a schematic diagram of the pump casing assembly structure;

[0022] Figure 3 This is a schematic diagram of the pump core assembly of the present invention;

[0023] Figure 4 This is a schematic diagram of the rotor structure in the pump core assembly;

[0024] Figure 5 This is a schematic diagram of the distribution shaft structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the cam structure of the present invention;

[0026] Figure 7 This is a schematic diagram of the phase difference between the two cams of the present invention;

[0027] Figure 8 This is a schematic diagram (front view and sectional view) of the double-acting plunger of the present invention;

[0028] Figure 9 This is a schematic diagram (axonometric view) of the double-acting plunger of the present invention;

[0029] Figure 10 This is a schematic diagram of the distribution sleeve structure of the present invention;

[0030] Figure 11 This is a schematic diagram (front view and sectional view) of the stator structure in the pump core assembly of the present invention;

[0031] Figure 12 This is a schematic diagram (axonometric view) of the stator structure in the pump core assembly of the present invention;

[0032] Figure 13 This is a schematic diagram of the cylinder block structure of the present invention;

[0033] Figure 14 This is a schematic diagram of the "internal and external flow distribution" principle of the present invention. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0037] like Figure 1 As shown, this embodiment of the invention provides a ball-bearing supported double-acting curved plunger pump, including a pump housing assembly and a pump core assembly. The pump housing assembly includes an upper end cover 2, a pump housing 4, and a rear end cover 8 arranged sequentially along the axis. The upper end cover 2, the pump housing 4, and the rear end cover 8 are fixed together by bolts to form the pump housing assembly structure.

[0038] Pump body components such as Figure 2 As shown, the pump casing assembly consists of a front cover 2, a pump casing 4, and a rear cover 8, which are fastened together by bolts and sealed by a sealing ring. The front cover 2 is provided with a locating pin hole 21, a shaft seal mounting hole 22, and a bearing mounting hole 23. The pump casing 4 is provided with a high-pressure flow channel 41, a sealing ring mounting groove 42, and a high-pressure outlet 43. The rear cover is provided with a locating pin hole 81, a sealing ring mounting groove 82, a bearing mounting hole 83, and a low-pressure inlet 84.

[0039] The pump core assembly is coaxially arranged along the axis inside the pump casing assembly, such as... Figure 3 As shown. The pump core assembly consists of a rotor structure and a stator structure, as shown respectively. Figure 4 and Figure 9 As shown, the rotor structure consists of a distribution shaft 1, a cam 3, ball bearings 11, a double-acting plunger 14, a distribution sleeve 7, and a synchronizing pin 15. The distribution shaft 1 and cam 3 transmit torque through a transmission flat structure, and their axial movement is restricted by bearings 10 and the distribution shaft 1. The distribution sleeve 7 rotates synchronously with the cam 3 and distribution shaft 1 via the synchronizing pin 15, jointly completing the distribution function. The double-acting plunger 14, plunger sleeve 15, and cylinder 5 form a closed annular space, the so-called plunger cavity. Due to the presence of the stator structure, when the rotor structure rotates, the double-acting plunger 14 reciprocates axially under the action of the cams 3 at both ends, causing the plunger cavity to simultaneously expand and contract, completing the expansion and compression of the fluid medium.

[0040] In this embodiment of the invention, the distribution shaft 1 has a hollow structure, such as... Figure 5As shown. The distribution shaft has a flat keyway 101, a bearing mounting surface 102, a pressure relief hole 103, a distribution shaft sealing strip 104, a distribution window 106, and a bearing mounting surface 105 arranged along its axis. The distribution shaft has a central hole 107 inside. The distribution shaft 1 integrates support and distribution functions into one unit. The support surfaces are distributed at both ends of the distribution shaft 1, and the distribution window 106 is located in the middle of the distribution shaft 1. There are two sets of distribution windows, which are distributed at 90° to each other. A distribution shaft sealing strip 104 of a certain width is distributed on both sides of the distribution window 106.

[0041] Cam 3 in the embodiment of the present invention Figure 6 As shown, cam 3 is an end-face cam structure with a double-peak, double-valley profile 31. A ball bearing groove 32, mirroring the profile's undulations, is located in the middle of the profile. In the pump core, there are two cams 3, both with identical structures, but their peaks and valleys are correspondingly distributed on the distribution shaft 1, as shown... Figure 7 As shown, the cam 3 plays a similar role in the pump core as the swashplate in a traditional axial piston pump, bearing the axial reciprocating motion of the double-acting piston 14.

[0042] The dual-acting plunger 14 of this invention is as follows: Figure 9 As shown, the overall design is thicker in the middle, thinner at both ends, and hollow at both ends. Multiple pressure-equalizing grooves 141 and flow holes 142 are symmetrically arranged on the outer diameter surfaces of both ends of the double-acting plunger 14, and ball sockets 144 are provided at both ends. At the larger diameter in the middle, the hollow inner diameters at both ends communicate with the outer diameter of the thinner shaft on the opposite side through inclined holes 146. When the double-acting plunger 14 moves to the left, the left plunger cavity becomes smaller, the fluid is compressed, and the high-pressure fluid enters the right central hole through the inclined hole 146, then flows out through the flow holes 142 and pressure-equalizing grooves 141, forming a hydrostatic oil film on the right smaller diameter. This helps improve the lubrication of the right plunger pair and increases its service life. The high-pressure fluid in the right central hole can also leak into the housing through the right ball socket. Due to the presence of the balls 11, a lubricating oil film can be formed at the balls 11, forming a hydrostatic support for the balls. Meanwhile, the balls and the double-acting plunger 14 are separated by a lubricating oil film, which reduces friction loss. The balls and the cam 3 are in a pure rolling motion, with low friction loss, which helps to improve the working efficiency of the double-acting curve plunger pump.

[0043] In other words, the plunger adopts a double-acting hollow structure, with the left and right plunger cavities communicating with their internal hollow flow channels through damping orifices. When the left plunger cavity is under high pressure, the high-pressure fluid in the plunger cavity enters the internal hollow flow channel on the right side of the plunger through the damping orifice. The ball bearings on the right side and the plunger ball socket form a ball-and-socket friction pair with hydrostatic support, which serves to lubricate and support the plunger. The flow distribution shaft and the flow distribution window on the flow distribution sleeve realize the intake and discharge of fluid by connecting and disconnecting with the flow distribution window on the cylinder block, thus completing the flow distribution function.

[0044] As can be seen, transmission flat structures are set at the contact points between the distribution shaft and the cam guide rail on both sides to realize the torque transmission function. The double-acting curve piston pump designed based on this core theory has more advantages than the traditional axial piston pump. This is because the cam in the double-acting curve piston pump has a double-peak and double-valley structure. The double-acting piston completes two axial reciprocating motions in one rotation cycle of the distribution shaft. At the same time, the piston is double-acting, and one piston is equivalent to four pistons in a traditional axial piston pump. This greatly increases the displacement of the piston pump. In other words, at the same speed and number of plungers, the double-acting curve plunger pump can achieve four times the flow rate of the traditional axial plunger pump, and the power-to-weight ratio is increased by four times. Since the plungers do not rotate, the plunger pair is not affected by the centrifugal force of the plungers, and the "ceiling effect" of the friction pair caused by high speed is "improved". The distribution sleeve and distribution shaft can be kept out of contact with the cylinder block, which greatly reduces the wear of the distribution pair, extends the service life, and enhances the anti-pollution ability. Since the fluid inlet is axial, the inlet pressure of the centrifugal pump can be increased, reducing the occurrence of cavitation. Since the plungers do not rotate, the oil churning loss is effectively reduced.

[0045] Preferably, in order to ensure that the theoretical outlet flow of the double-acting curve plunger pump is pulsation-free, the number of double-acting plungers is 8.

[0046] In this embodiment of the invention, the flow distribution sleeve 7 is as follows: Figure 10 As shown, the overall structure is a thin-walled sleeve. One side of the distribution sleeve 7 has a pair of through holes for installing the synchronizing pin 15, ensuring its synchronous rotation with the cam. The other side has a pair of rectangular distribution windows 71 to distribute the high-pressure fluid. The distribution windows 71 are symmetrically distributed, and the inner wall is subjected to symmetrical hydraulic pressure from the high-pressure fluid, ensuring a good lubricating film between the distribution sleeve 7 and the cylinder 5, resulting in good lubrication conditions. Ideally, the distribution sleeve 7 should not contact the cylinder 5, forming a so-called "ideal distribution pair." Two distribution sleeves 7 are provided, with the left and right distribution windows distributed at 90°, completing the alternating distribution of fluid between the left and right sides of the plunger cavity.

[0047] Stator structure as follows Figure 11 As shown, it consists of cylinder 5, plunger sleeve 13, plunger sleeve baffle 12 and bolts, etc. The stator structure is fixed to the cylinder limit sleeve 6 and pump housing assembly by locating pins.

[0048] In this embodiment of the invention, cylinder 5 is as follows: Figure 13As shown, the overall structure is honeycomb-like. A central hole 58 is located in the center of the cylinder body 5, serving as the low-pressure flow channel for the double-acting curved plunger pump. Eight through holes 510 are circumferentially distributed around the central hole, forming a sealed space—the plunger cavity—with the plunger sleeve 13 and the double-acting plunger 14. The central hole 58 and the through holes 510 communicate through a rectangular distribution window 56, which is the low-pressure distribution window. The through holes 510 communicate with the outer diameter of the cylinder body 5 through a distribution window 57, which is the high-pressure distribution window. Symmetrically distributed sleeve structures 54 are located on the outer diameter of the cylinder body 5. The sleeves 54 form a deep circular groove with the outer diameter of the cylinder body 5, creating a gap seal with the distribution sleeve 7. The sleeve structures 54 have the same number and size of rectangular windows distributed circumferentially as the outer diameter of the cylinder body 5. When the plunger cavity is in the oil discharge stroke, the distribution window 71 on the distribution sleeve 7 communicates with the high-pressure distribution window 57 of the cylinder block. The high-pressure fluid flows through the distribution window on the sleeve structure 54 to the high-pressure flow channel 511, completing the distribution of the high-pressure fluid. Two sealing grooves 512 are provided at both ends of the high-pressure flow channel for sealing the high-pressure fluid.

[0049] The so-called "internal and external flow distribution" principle in this embodiment of the invention is as follows: Figure 14 As shown, during the operation of a double-acting curve piston pump, each pair of adjacent double-acting pistons operates under the same conditions. Taking the left side of the piston chamber as an example, when the two adjacent piston chambers on the left are in the compression stroke (e.g., pistons 3 and 4), the other two adjacent piston chambers symmetrically positioned on the left (e.g., pistons 7 and 8) are also in the compression stroke. At this time, the distribution window 106 on the distribution shaft 1 is closed to the piston chamber, and the distribution window 71 on the distribution sleeve 7 communicates with the high-pressure flow channel 41. Simultaneously, when the two piston chambers adjacent to the compression stroke are in the expansion stroke (e.g., pistons 1 and 2), the other two piston chambers symmetrically positioned on the left are also in the expansion stroke (e.g., pistons 5 and 6). At this time, the distribution window 106 on the distribution shaft 1 communicates with the piston chamber, and the distribution window 71 on the distribution sleeve 7 is closed with the high-pressure flow channel 41. At this point, the plunger chamber alternately draws in and discharges oil, and the low-pressure distribution window 106 of the distribution shaft 1 communicates alternately with the low-pressure distribution window 56 of the cylinder block 5. Meanwhile, the high-pressure distribution window 57 of the cylinder block 5 communicates alternately with the high-pressure distribution window 71 of the distribution sleeve 7, thus completing the "internal and external distribution" of the double-acting curve plunger pump.

[0050] As can be seen, this invention provides a ball-supported double-acting curved plunger pump, including front / rear end caps, a housing, a distribution shaft, a cylinder, a double-acting plunger, a plunger sleeve, a plunger sleeve baffle, balls, a cam, a distribution sleeve, a cylinder positioning sleeve, bearings, shaft seals, and sealing rings. The front end cap, pump housing, and rear end cap are connected by screws to form a pump housing assembly. The pump core assembly is placed inside the pump housing assembly and the axial movement of the cylinder is restricted by the cylinder positioning sleeve. The cylinder and pump housing assembly cooperate to form a high-pressure flow channel. The pump core assembly is divided into two parts: a rotor structure (composed of a distribution shaft, a double-acting piston, balls, and a distribution sleeve) and a stator structure (composed of a cylinder, a plunger sleeve, a plunger sleeve baffle, bolts, and sealing rings). The distribution shaft, distribution sleeve, and cam in the rotor structure rotate around the axis under the drive of a motor to complete the distribution function. The double-acting plunger reciprocates axially under the constraint of the cylinder and the cam to complete the suction and discharge functions. This invention simplifies the system structure by adopting a motion structure of "rotating distribution on both inner and outer sides + reciprocating suction and discharge of oil by plunger + double action", increases the possibility of further increasing the speed, improves the working condition of the distribution pair, and greatly improves the power-to-weight ratio of the plunger pump. This is of great significance for improving the performance parameters, working reliability and system efficiency of the fuel pump.

[0051] In summary, this invention provides a ball-supported double-acting curved plunger pump. This pump employs a rotating distribution shaft and distribution sleeve on both the inner and outer sides for distribution, while the cylinder body remains stationary. The double-acting piston reciprocates to draw and discharge oil, forming a motion structure of "rotating distribution on both sides + reciprocating piston suction and discharge + double-acting." Compared to a traditional plunger pump, this simplifies the system structure. Specifically, the distribution shaft drives the front and rear cam guides and distribution sleeve to rotate, while the cylinder body remains stationary. The plunger and balls reciprocate axially under the action of the cam guides, causing the volume of the plunger cavities on both sides to alternately increase and decrease, achieving the expansion and compression of the fluid medium and completing the suction and discharge functions. Furthermore, this invention uses a ball hydrostatic support structure, replacing the swashplate slipper of the traditional plunger pump with a ball cam mechanism, converting the sliding friction pair into a rolling friction pair. This improves the working conditions of the friction pair, facilitates the formation of a lubricating oil film, reduces friction loss, and increases working efficiency. This invention employs a double-acting plunger and a double-peak, double-valley cam structure. One double-acting plunger is equivalent to four traditional plungers, allowing for a smaller and lighter design while maintaining the same performance parameters. This is significant for applications in aerospace, mobile machinery, and other fields requiring high power density and small size. The invention utilizes a rotating distribution shaft and distribution sleeve with a fixed distribution cylinder, ensuring the distribution pairs do not contact the cylinder, reducing wear and effectively guaranteeing long-term stable operation of the pump core. In this structure, oil is drawn in at the distribution shaft and discharged at the distribution sleeve. The pump inlet flow channel is simple and unobstructed, resulting in low flow resistance and significantly improving the pump's self-priming capability. Furthermore, the plunger only undergoes reciprocating motion, reducing the pv value limitation of centrifugal force generated by the plunger pair's rotational motion and minimizing oil churning losses, making it more suitable for high-speed applications.

[0052] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0053] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A ball supported double acting curved plunger pump characterized by, The plunger pump comprises: A pump shell assembly comprising an upper end cover, a pump shell and a rear end cover arranged coaxially along an axis in sequence, the upper end cover, the pump shell and the rear end cover being fixedly connected to form the pump shell assembly, the pump shell being provided with a high-pressure flow channel and a high-pressure outlet; A pump core assembly arranged coaxially along the axis in the pump shell assembly, the pump core assembly comprising a rotor structure and a stator structure, the rotor structure comprising a flow distribution shaft, a cam, a ball, a double-acting plunger, a flow distribution sleeve and a synchronization pin, and the stator structure comprising a cylinder body, a plunger sleeve and a plunger sleeve baffle, wherein: the flow distribution shaft is connected to the cam through a transmission flat structure and is limited in axial movement by a bearing and the flow distribution shaft, the flow distribution sleeve is synchronously rotated with the cam and the flow distribution shaft through the synchronization pin, and the flow distribution sleeve and the cam and the flow distribution shaft together complete the flow distribution function; the double-acting plunger and the plunger sleeve and the cylinder body form a closed annular space, i.e. a plunger cavity; due to the presence of the stator structure, when the rotor structure rotates, the double-acting plunger reciprocates axially under the action of the cams at both ends, the plunger cavity simultaneously increases and decreases, and the expansion and compression of the fluid medium are completed. The pump shell assembly and the pump core assembly cooperate to realize the flow distribution on the inner and outer sides of the plunger pump.

2. A ball supported double acting curve piston pump according to claim 1, characterized in that The cam is an end face cam structure and adopts a double-peak double-valley profile, a ball groove with the same fluctuation as the profile is arranged at the middle part of the profile, in the pump core, there are two cams which are the same in structure but are correspondingly distributed on the peaks and valleys of the flow distribution shaft, and the cam bears the axial reciprocating movement of the double-acting plunger.

3. A ball supported double acting curve piston pump according to claim 1 or 2, characterized in that The double-acting plunger has a design form of thick in the middle and thin at both ends and hollow at both ends, a plurality of pressure equalizing grooves and through-flow holes are symmetrically arranged on the outer diameter surfaces of both ends of the double-acting plunger, ball sockets are arranged at both ends, and the inner diameters of the hollows at both ends are communicated with the outer diameter groove of the thin shaft at the opposite side through inclined holes; when the double-acting plunger moves to the left, the left plunger cavity becomes smaller, the fluid is compressed, the high-pressure fluid enters the right central hole through the inclined hole, flows out through the through-flow hole and the pressure equalizing groove, and a static pressure oil film is formed at the right small diameter, the high-pressure fluid in the right central hole can also leak into the shell through the right ball socket, due to the presence of the ball, a lubricating oil film can be formed at the ball, forming a ball static pressure support; at the same time, the ball and the double-acting plunger are separated by the lubricating oil film, and the ball and the cam are in pure rolling motion.

4. A ball supported double acting curve piston pump according to claim 3, characterized in that The flow distribution shaft is a hollow structure, the flow distribution shaft is provided with a flat key groove, a bearing mounting surface, a pressure relief hole, a flow distribution shaft sealing strip, a flow distribution window and a bearing mounting surface along the axis, the inside of the flow distribution shaft is a central hole, the flow distribution shaft integrates the support and flow distribution functions, the support surfaces are distributed at both ends of the flow distribution shaft, the flow distribution window is arranged at the middle part of the flow distribution shaft, the flow distribution window is 2 groups, the two groups are distributed at 90° to each other, and the flow distribution shaft sealing strips with a certain width are distributed on both sides of the flow distribution window.

5. A ball supported double acting curved vane pump according to claim 4 wherein, The flow distribution sleeve is in the form of a thin-walled sleeve structure, one side of the flow distribution sleeve is provided with a pair of through holes for installing the synchronization pin to ensure synchronous rotation with the cam; the other side is provided with a pair of rectangular flow distribution windows to complete the flow distribution of the high-pressure fluid; the flow distribution windows are symmetrically distributed, the inner wall is subjected to symmetric hydraulic pressure of the high-pressure fluid, and the lubricating oil film can be formed between the flow distribution sleeve and the cylinder body.

6. A ball supported double acting curved vane pump according to claim 5 wherein, The flow distribution sleeve is provided with two, and the flow distribution windows of the left and right two are distributed at 90°, completing the alternating flow distribution of the left and right sides of the plunger cavity.

7. A ball supported double acting curved vane pump as claimed in claim 5 wherein, The cylinder body is in the form of a honeycomb structure, and a center hole is arranged in the middle of the cylinder body, which is a low-pressure flow channel of the double-acting curved plunger pump; eight through holes are arranged around the center hole in a circumferential distribution, and the through holes and the plunger sleeve and the double-acting plunger form a closed space, i.e., a plunger cavity; the center hole and the through hole are communicated through a rectangular flow distribution window, which is a low-pressure flow distribution window; the through hole and the outer diameter of the cylinder body are communicated through a flow distribution window, which is a high-pressure flow distribution window; sleeve structures are symmetrically arranged at the outer diameter of the cylinder body, and the sleeve and the outer diameter of the cylinder body form a deep circular groove for forming a gap seal with the flow distribution sleeve; the sleeve structure is distributed with the same number and size of rectangular windows along the circumferential direction of the outer diameter of the cylinder body; when the plunger cavity is in the oil discharge stroke, the flow distribution window on the flow distribution sleeve is communicated with the high-pressure flow distribution window of the cylinder body, and the high-pressure fluid flows to the high-pressure flow channel through the flow distribution window on the sleeve structure, completing the flow distribution of the high-pressure fluid.

8. A ball supported double acting curved vane pump according to any one of claims 1 to 7, characterized in that The implementation of the inner and outer flow distribution is as follows: During the operation of the double-acting curved plunger pump, every two adjacent double-acting pistons are in the same working condition. For the left side of the plunger cavity, when the two adjacent plunger cavities on the left side are in the compression stroke, the other two adjacent plunger cavities symmetrically with the center are also in the compression stroke, at which time the flow distribution window on the flow distribution shaft is closed with the plunger cavity, and the flow distribution window on the flow distribution sleeve is communicated with the high-pressure flow channel; at the same time, the two plunger cavities adjacent to the compression stroke are in the expansion stroke, and the other two plunger cavities symmetrically with the center are also in the expansion stroke, at which time the flow distribution window on the flow distribution shaft is communicated with the plunger cavity, and the flow distribution window on the flow distribution sleeve is closed with the high-pressure flow channel; thus, the plunger cavity alternately sucks and discharges oil, the low-pressure flow distribution window of the flow distribution shaft is alternately communicated with the low-pressure flow distribution window of the cylinder body, and the high-pressure flow distribution window of the cylinder body is alternately communicated through the high-pressure flow distribution window of the flow distribution sleeve, completing the "inner and outer flow distribution" of the double-acting curved plunger pump.

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