Roller plunger pump

Abstract

The invention provides a roller plunger pump. The roller plunger pump is composed of an integrated double-face cam guide rail, a flow distribution transmission shaft, a cylinder body and roller plungers. Along with rotation of the integrated double-sided cam guide rail, a roller in the roller plunger assembly rolls on the integrated double-sided cam guide rail, so that a plunger in the assembly is driven to reciprocate, the oil suction and discharge functions of a plunger cavity are achieved, oil liquid pumping is finally completed through a shaft flow distribution mechanism composed of a flow distribution transmission shaft and a cylinder body, and the function of a pump is achieved. And through the change of the flow distribution transmission shaft, the structural characteristics of the cylinder body and the flow channel, the shaft flow distribution mechanism can also realize the flow distribution function of oil, so that the pump is changed into a multi-port pump with a plurality of oil inlets and oil outlets, such as a one-oil-inlet (oil-outlet) two-oil-outlet (oil-inlet) three-port pump, a two-oil-inlet two-oil-outlet four-port pump and the like. The multi-port pump can achieve direct control over the direction and speed of hydraulic cylinders of different structure types, for example, a three-port pump can directly control an asymmetric hydraulic cylinder, a four-port pump can achieve constant-power output of the hydraulic cylinders, and a new solution is provided for a pump control hydraulic system.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic pumps, and in particular to a roller plunger pump. Background Art

[0002] The actuator in the hydraulic system is a reciprocating hydraulic cylinder or a rotating swing cylinder. Taking the more commonly used hydraulic cylinder as an example, it has two typical structures: a single-rod hydraulic cylinder and a double-rod hydraulic cylinder. For the traditional throttling and variable displacement hydraulic valve control system, it is usually a single-rod hydraulic cylinder. In order to achieve the reversing and speed control of the hydraulic cylinder, a servo valve or a proportional valve is generally used to complete it, and a combination of a relief valve and a fixed displacement pump, a constant pressure variable pump, or a load-sensitive pump is directly used to control the output force of the hydraulic cylinder. For the hydraulic system using a relief valve + a fixed displacement pump, a relief valve + a constant pressure variable pump combination, the former has energy loss caused by the fluid throttling of the relief valve and the throttle valve, and the latter has no overflow loss, but still has throttling loss, especially when the hydraulic cylinder is running at low load, the throttling loss is more obvious; while for the hydraulic control system using a load-sensitive pump, there is no overflow loss, and its throttling loss is also small, but it needs a load-sensitive valve for control, and the entire system is more complicated.

[0003] The pump-controlled hydraulic system is a product of the high degree of cross-integration of motor technology and hydraulic technology. With the rapid development of motor technology and electrification trends in recent years, the technical solutions of pump-controlled hydraulic systems using variable speed flow control and regulation have also received more and more attention and favor. Compared with traditional throttling and variable displacement hydraulic control systems, it has greatly improved efficiency and integration, and has the dual advantages of flexible motor control and high power density of hydraulics. For the pump-controlled hydraulic system, there is no valve to control the actuator in the system. The pump is directly connected to the actuator, and the direction and speed control of the actuator is completed by the motor driving the pump to switch forward and reverse and control the forward and reverse speed. When the actuator is a double-rod symmetrical cylinder, due to the symmetry of the cylinder, the liquid volumes of the left and right chambers are almost exactly the same. When the motor drives the pump to rotate, the oil in one chamber can be pumped to the other chamber, and the missing or excess trace oil can be replenished or overflowed through the oil replenishment valve and the overflow valve, and finally the reciprocating motion of the hydraulic cylinder is realized; when the actuator is a single-rod asymmetric cylinder, the liquid volume of the rodless chamber is larger than that of the rod chamber. If the pump is directly connected to the hydraulic cylinder, the pump control system will not work properly due to the asymmetry of the oil volume. At this time, an oil suction and discharge valve group composed of two hydraulic control one-way valves and an additional oil replenishment tank are required to solve this problem: when the hydraulic cylinder is extended, the volume of the rodless chamber increases, and the pump simultaneously pumps the oil in the rod chamber and the oil in the replenishment tank to the rodless chamber; when the hydraulic cylinder is retracted, the volume of the rod chamber increases, and the pump pumps part of the oil in the rodless chamber to the rod chamber, and the other part is pumped back to the replenishment tank, so as to realize the reciprocating motion of the hydraulic cylinder.

[0004] In addition, the ideal operating condition of a hydraulic cylinder is a constant power working scenario, and its working process is usually first a fast extension movement with a small load (low pressure and high flow), then a slow movement with a large load (high pressure and low flow), and finally a fast retraction movement with a small load (low pressure and high flow). For the traditional existing throttling and variable displacement hydraulic control systems, both fast movement conditions have the problem of large energy loss; and for the existing pump-controlled hydraulic control system, there is a problem that high-power slow movement has high requirements for the motor and its motor control, and the motor's low-speed performance cannot be achieved.

[0005] Therefore, the above-mentioned prior art has at least the following technical problems: for valve-controlled hydraulic systems, it is possible to control hydraulic cylinders of different structures, but there are problems of complex structure, low integration and low energy utilization; for pump-controlled hydraulic systems, the control of single-rod cylinders requires additional suction and discharge valves. In addition, for occasions requiring constant power output control, the requirements for the motor are high and the performance cannot be met. Summary of the invention

[0006] The present invention provides a roller piston pump and an axial flow distribution mechanism thereof, thereby solving the technical problems in the prior art that the valve-controlled hydraulic cylinder has a complex structure and low energy utilization rate, the pump-controlled single-rod hydraulic cylinder requires an additional suction and discharge valve group, and the low-speed performance of the pump-controlled constant-power hydraulic cylinder motor does not meet the requirements.

[0007] In order to solve the above technical problems, the present invention provides a roller piston pump, which adopts a plug-in structure, including a pump end cover, and defines the direction along the central axis of the pump end cover or parallel to the central axis of the pump end cover as the axial direction, the direction around the central axis of the pump end cover as the circumferential direction, and one end along the axial direction is the left end, and the other end opposite to the axial direction is the right end; the direction toward the middle position of the central axis is the inward direction, and the opposite direction is the outward direction;

[0008] A pump core is provided on the right side of the pump end cover, and the middle part of the pump core is a cylinder body coaxially arranged with the pump end cover. A central through hole distributed axially is provided at the center position of the cylinder body, and a distribution transmission shaft is installed through the central through hole, and the distribution transmission shaft rotates along the circumferential direction in the central through hole of the cylinder body through the bearing limiter installed on the left and right end faces of the cylinder body, and the inner circumferential surface of the central through hole of the cylinder body cooperates with the outer circumferential surface of the shoulder of the distribution transmission shaft to form the shaft distribution pair of the pump; it is characterized in that:

[0009] An even number of axial plunger holes are evenly arranged on the left and right end faces of the cylinder body along the circumferential direction of the central axis, and the axial projection of the plunger hole on the left end face of the cylinder body and the axial projection of the plunger hole on the right end face of the cylinder body are alternately and evenly distributed; the plunger of the roller plunger assembly is slidably arranged in the plunger hole, and the plunger hole and the plunger end face form a piston cavity; the large roller of the roller plunger assembly rolls on the large circumferential curved surface, and the small roller of the roller plunger assembly rolls on the small circumferential curved surface, so that the plunger reciprocates and changes the volume of the piston cavity;

[0010] The inner circumferential surface of the central through hole of the cylinder body is provided with radial through holes connected to the plunger hole on the left end surface of the cylinder body and the plunger hole on the right end surface of the cylinder body. The radial through holes are evenly distributed along the circumference of the axis and serve as flow distribution windows of the cylinder body. The number of radial through holes is equal to the number of plunger holes. The outer circumferential surface of the cylinder body is provided with outer annular grooves as inlet and outlet oil flow channels. The number of inlet and outlet oil annular flow channels is equal to the number of inlets and outlets of the pump. The inner circumferential surface of the central through hole of the cylinder body is also provided with inner annular grooves with the same number as the outer annular grooves on the outer circumferential surface. The inner and outer annular grooves communicate with each other through radial through holes distributed between the plunger holes.

[0011] The distribution transmission shaft has a shoulder, and the left and right ends of the shoulder are respectively provided with extension shafts, and the left and right extension shafts are respectively fixedly installed with an integrated double-sided cam guide rail, and the high point of the left integrated double-sided cam guide rail is always facing the high point of the right integrated double-sided cam guide rail; the left extension shaft has an extension part, which serves as an introduction connection for the power source;

[0012] The shoulder of the distribution transmission shaft is provided with annular channels equal in number to the annular flow channels of the cylinder body for oil inlet and outlet; the outer circumferential surface of the distribution transmission shaft located between the annular flow channels is provided with a V-shaped distribution groove along the axis, connecting the annular channels with the cylinder body distribution window;

[0013] A relief groove is provided on the generatrix formed by the V-shaped distribution groove and the outer circumferential surface of the distribution transmission shaft shoulder. The arrangement position of the relief groove and the position of the cylinder distribution window are on the same radial cross section. The distance between the peak points of two adjacent relief grooves along the circumferential direction is consistent with the width of the cylinder distribution window along the circumferential direction. With the rotation of the distribution transmission shaft, the V-shaped distribution groove and its relief groove will periodically intersect and communicate with the cylinder distribution window, so that the cylinder plunger hole communicates with the annular channel of the distribution transmission shaft, while realizing the precise distribution of the oil in the plunger hole to the cylinder oil inlet and outlet annular flow channel, reducing the backflow of the output flow and the output pressure fluctuation; preferably, the shape of the relief groove is a triangular groove or an arched groove;

[0014] The one-piece double-sided cam guide rail is provided with two relatively large and small circular curved surfaces, the large and small circular curved surfaces have two high points and two low points, the four high and low points are staggered and evenly distributed in the circumferential direction, and the high point of the large circular curved surface is always opposite to the low point of the small circular curved surface, and the surface change law between any high and low points of the large and small circular curved surfaces is consistent, and as a preferred embodiment, the surface change law adopts an equal acceleration and equal deceleration motion law curve;

[0015] The roller plunger assembly comprises a plunger with a U-shaped notch at one end, a large roller, a small roller and a roller shaft, wherein the large roller is arranged in the U-shaped notch of the plunger through the roller shaft, and the small roller is arranged on one side of the end face of the U-shaped notch of the plunger through the roller shaft;

[0016] The plunger is arranged in the plunger hole of the cylinder body, and is enclosed with the cylinder body to form the oil suction and discharge volume chamber of the pump. The large and small rollers are arranged between the large and small circumferential surfaces of the integrated double-sided cam guide rail, and the large roller is in contact with the large circumferential surface, and the small roller is in contact with the small circumferential surface. Furthermore, in order to better improve the transmission accuracy, as a preferred embodiment, the small roller adopts a roller with elastic plastic deformation on the outer ring, and the preload force is increased by the deformation amount to eliminate the gap between the roller and the curved surface.

[0017] The number of even-numbered plunger holes on the cylinder body is a multiple of four, and the commonly used values ​​are eight or sixteen. Correspondingly, the number of the cylinder body flow distribution windows is consistent with the number of plunger holes. The change in the number of plunger holes does not affect the change of the pump function. More plunger holes will make the output flow pulsation of the pump smaller, and the plunger will be arranged more compactly in the circumferential direction. Further, the roller plunger pump is a two-port pump;

[0018] The left and right side end surfaces of the two-port pump cylinder body are respectively evenly distributed with four plunger holes in the circumferential direction of the central axis, and the middle position of the central through hole of the cylinder body is provided with eight radial holes evenly distributed in the circumference, four of which are in communication with the plunger on the left end surface of the cylinder body, and four of which are in communication with the plunger on the right end surface of the cylinder body; the outer circumferential surface of the cylinder body is provided with two annular grooves, one of which is located on the left side of the center of the cylinder body, serving as the outer high-pressure flow channel of the pump, and the other is located on the right side of the center of the cylinder body, serving as the outer low-pressure flow channel of the pump; the inner surface of the central through hole of the cylinder body is also provided with two annular grooves, one of which is arranged on the left side of the central through hole of the cylinder body, serving as the inner high-pressure flow channel of the pump, and the other is arranged on the right side of the central through hole of the cylinder body, serving as the inner low-pressure flow channel of the pump; the inner and outer high-pressure flow channels, and the inner and outer low-pressure flow channels are respectively penetrated through radial through holes evenly distributed in the circumference between the two plunger holes;

[0019] The two-port pump distribution transmission shaft shoulder is provided with two high-pressure and low-pressure annular flow passages corresponding to the high-pressure flow passage and the internal low-pressure flow passage in the cylinder body, and four V-shaped distribution grooves evenly distributed along the circumferential direction are provided in the middle position between the high-pressure and low-pressure annular flow passages, two of which are high-pressure distribution grooves and the other two are low-pressure distribution grooves. The high-pressure and low-pressure distribution grooves are staggered in the circumferential direction, and the high-pressure distribution groove communicates with the high-pressure annular flow passage, and the low-pressure distribution groove communicates with the low-pressure annular flow passage;

[0020] When external power drives the rotating distribution shaft to make a rotary motion, the integrated double-sided cam guide rotates under the drive of the distribution transmission shaft, forcing the large and small rollers to rotate around their own roller axes on the circumferential surface of the integrated double-sided cam guide, which is similar to the axial displacement change of the circumferential surface of the integrated cam guide driving the plunger to reciprocate along the axial direction: when the large roller is forced to move on the integrated cam guide, the plunger moves axially close to the center of the cylinder body, and the volume of the plunger cavity decreases. At this time, the cylinder body distribution shaft communicating with the plunger cavity is The flow window intersects with the high-pressure V-shaped distribution groove of the distribution transmission shaft, and communication occurs. The oil in the plunger cavity that changes due to the reduction in volume flows out to the high-pressure flow channel of the cylinder body through the communication flow channel; when the small roller is forced to move on the integrated cam guide rail, the plunger moves axially away from the center of the cylinder body, and the volume of the plunger cavity increases. At this time, the cylinder body distribution window that communicates with the plunger cavity intersects with the low-pressure V-shaped distribution groove of the distribution transmission shaft, and communication occurs. The oil in the plunger cavity that changes due to the increase in volume flows into the low-pressure flow channel of the cylinder body through the communication flow channel. Through the above process, with the continuous rotation of the rotating distribution shaft, the size of each plunger volume cavity of the pump changes regularly, realizing the suction and discharge function of the oil, and completing the work of the pump in and out.

[0021] Further, the roller piston pump is a three-port pump;

[0022] The left and right side end surfaces of the three-port pump cylinder body are respectively provided with four plunger holes evenly distributed along the circumferential direction of the central axis; the outer circumferential surface of the cylinder body is provided with three annular grooves, which are, from left to right, the first high-pressure outer annular flow channel, the second low-pressure outer annular flow channel, and the third high-pressure outer annular flow channel; the inner surface of the central through hole of the cylinder body is also provided with three annular grooves corresponding to the outer circumferential surface of the cylinder body, which are, from left to right, the first high-pressure inner annular flow channel, the second low-pressure inner annular flow channel, and the third high-pressure inner annular flow channel; the one-to-one pair The corresponding inner and outer annular grooves are connected through radial through holes evenly distributed circumferentially between the two plunger holes; four radial holes evenly distributed circumferentially are opened between the first high-pressure inner annular flow channel and the second low-pressure inner annular flow channel of the central through hole of the cylinder body, which are connected through the four plunger holes on the left end face of the cylinder body to form a left distribution window; four radial holes evenly distributed circumferentially are opened between the second low-pressure inner annular flow channel and the third high-pressure inner annular flow channel of the central through hole of the cylinder body, which are connected through the four plunger holes on the right end face of the cylinder body to form a right distribution window;

[0023] The shoulder of the three-port pump distribution transmission shaft is provided with three annular grooves from left to right, corresponding one by one to the annular grooves in the center hole of the cylinder body, which are respectively the first high-pressure annular flow channel, the second low-pressure annular flow channel, and the third high-pressure annular flow channel; four V-shaped distribution grooves evenly distributed along the axial circumference are provided between the first high-pressure annular flow channel and the second low-pressure annular flow channel, which are used to communicate with the left distribution window of the cylinder body, two of which are high-pressure distribution grooves, and the other two are low-pressure distribution grooves. The high and low-pressure distribution grooves are staggered in the circumferential direction, and the high-pressure distribution groove communicates with the first high-pressure annular flow channel, and the low-pressure distribution groove communicates with the second low-pressure annular flow passages communicate; four V-shaped flow distribution grooves evenly distributed along the axial circumference are opened between the second low-pressure annular flow passage and the third high-pressure annular flow passage, which are used to communicate with the right flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves, and the other two are low-pressure flow distribution grooves, the high and low-pressure flow distribution grooves are staggered in the circumferential direction, and the high-pressure flow distribution groove communicates with the third high-pressure annular flow passage, and the low-pressure flow distribution groove communicates with the second low-pressure annular flow passage; the eight V-shaped flow distribution grooves are arranged symmetrically in space with the second low-pressure annular flow passage as the mirror center, and the left high-pressure flow distribution groove is arranged axially parallel to the right high-pressure flow distribution groove;

[0024] When the pump starts to suck and discharge oil, a portion of the oil sucked from the second low-pressure outer annular flow channel of the cylinder body is discharged to the first high-pressure outer annular flow channel through the left distribution window of the cylinder body through the distribution mechanism composed of the cylinder body and the distribution transmission shaft, and the other portion is discharged to the third high-pressure outer annular flow channel through the right distribution window of the cylinder body, so that the pump can realize the function of a three-port pump with one oil inlet and two oil outlets.

[0025] Further, the roller piston pump is a four-port pump;

[0026] The left and right end surfaces of the four-port pump cylinder body are respectively evenly arranged with eight plunger holes along the circumferential direction of the central axis, four of which are large plunger holes and the other four are small plunger holes, and the large and small plunger holes are staggered in the circumferential direction; the outer circumferential surface of the cylinder body is provided with four annular grooves, which are, from left to right, the first low-pressure outer annular flow channel, the second high-pressure outer annular flow channel, the third low-pressure outer annular flow channel, and the fourth high-pressure outer annular flow channel; the inner surface of the central through hole of the cylinder body is also provided with four annular grooves corresponding to the outer circumferential surface of the cylinder body, which are, from left to right, the first low-pressure inner annular flow channel, the second high-pressure inner annular flow channel, the third low-pressure inner annular flow channel, and the fourth high-pressure inner annular flow channel; the one-to-one corresponding inner and outer annular grooves are penetrated by radial through holes evenly distributed circumferentially between the two plunger holes. Through communication; four radial holes evenly distributed around the circumference are opened between the first low-pressure inner annular flow channel and the second high-pressure inner annular flow channel of the central through hole of the cylinder body, which are communicated through the four large plunger holes on the left end face of the cylinder body to form a left distribution window for distributing flow to the large plunger on the left end face; eight radial holes evenly distributed around the circumference are opened between the second annular groove and the third annular groove of the central through hole of the cylinder body, which are communicated through the eight small plunger holes on the left and right end faces of the cylinder body to form an intermediate distribution window for distributing flow to the small plungers on the left and right end faces; four radial holes evenly distributed around the circumference are opened between the third annular groove and the fourth annular groove of the central through hole of the cylinder body, which are communicated through the four large plunger holes on the right end face of the cylinder body to form a right distribution window for distributing flow to the large plunger on the right end face;

[0027] The four-port pump distribution transmission shaft shoulder is provided with four annular grooves from left to right, corresponding to the annular grooves in the center hole of the cylinder body, and are respectively the first low-pressure annular flow channel, the second high-pressure annular flow channel, the third low-pressure annular flow channel, and the fourth high-pressure annular flow channel;

[0028] The core of the flow distribution transmission shaft shoulder is provided with four inner flow channels evenly distributed around the circumference, two of which are high-pressure inner flow channels and the other two are low-pressure inner flow channels. The high-pressure inner flow channels and the low-pressure inner flow channels are staggered in the circumferential direction, and the high-pressure inner flow channel is connected to the fourth high-pressure annular flow channel through and through, and the low-pressure inner flow channel is connected to the first low-pressure annular flow channel through and through;

[0029] Four V-shaped flow distribution grooves evenly distributed along the axial circumference are provided between the first low-pressure annular flow channel and the second high-pressure annular flow channel, which are used to communicate with the left flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves, and the other two are low-pressure flow distribution grooves. The high-pressure and low-pressure flow distribution grooves are staggered in the circumferential direction, and the high-pressure flow distribution groove is connected to the fourth high-pressure annular flow channel through the high-pressure inner flow channel of the flow distribution transmission shaft, and the low-pressure flow distribution groove is connected to the first low-pressure annular flow channel through the low-pressure inner flow channel of the flow distribution transmission shaft;

[0030] Four V-shaped flow distribution grooves evenly distributed along the axial circumference are provided between the third low-pressure annular flow channel and the fourth high-pressure annular flow channel, which are used to communicate with the right flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves and the other two are low-pressure flow distribution grooves. The high-pressure and low-pressure flow distribution grooves are staggered in the circumferential direction, and the high-pressure flow distribution groove is connected with the fourth high-pressure annular flow channel through the high-pressure inner flow channel of the flow distribution transmission shaft, and the low-pressure flow distribution groove is connected with the first low-pressure annular flow channel through the low-pressure inner flow channel of the flow distribution transmission shaft; and the high-pressure flow distribution groove between the first low-pressure annular flow channel and the second high-pressure annular flow channel and the high-pressure flow distribution groove between the third low-pressure annular flow channel and the fourth high-pressure annular flow channel are arranged in parallel in the axial direction;

[0031] Four V-shaped flow distribution grooves evenly distributed along the axial circumference are provided between the second high-pressure annular flow channel and the third low-pressure annular flow channel, which are used to communicate with the flow distribution window in the middle of the cylinder body, two of which are high-pressure flow distribution grooves, and the other two are low-pressure flow distribution grooves. The high-pressure flow distribution grooves and the low-pressure flow distribution grooves are staggered in the circumferential direction, and the high-pressure flow distribution grooves communicate with the second high-pressure annular flow channel, and the low-pressure flow distribution grooves communicate with the second low-pressure annular flow channel; and the high-pressure flow distribution groove between the second high-pressure annular flow channel and the third low-pressure annular flow channel and the high-pressure flow distribution groove between the third low-pressure annular flow channel and the fourth high-pressure annular flow channel are arranged in parallel in the axial direction;

[0032] When the pump starts to suck and discharge oil, the oil sucked from the first low-pressure outer annular flow channel of the cylinder body is discharged to the fourth high-pressure outer annular flow channel through the left distribution window and the right distribution window of the cylinder body through the distribution mechanism composed of the cylinder body and the distribution transmission shaft. Since the distribution plunger is a large plunger, the flow rate output by the fourth high-pressure outer annular flow channel is relatively large; the oil sucked from the third low-pressure outer annular flow channel of the cylinder body is discharged to the second high-pressure outer annular flow channel through the middle distribution window of the cylinder body. Since the distribution plunger is a small plunger, the flow rate output by the second high-pressure outer annular flow channel is relatively small. Finally, the pump can realize the simultaneous output of two different flow rates, large and small, that is, the function of a two-inlet, two-outlet, four-port pump is realized.

[0033] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0034] (1) The roller piston pump described in the present invention adopts an integrated double-sided cam guide having two large and small circular curved surfaces. The large circular curved surface is used for the oil discharge work of the piston, and the small circular curved surface is used for the oil suction work of the piston. Therefore, only one cam guide is required to drive the reciprocating motion of the piston. The large and small curved surfaces processed in an integrated manner have higher precision, so that the gap between the large and small rollers and the guide is better, and the reciprocating motion of the piston is driven more smoothly. Compared with other roller piston pumps, since the integrated double-sided cam guide has a reset small circular curved surface, the roller piston moving part located at the left end of the cylinder body and the roller piston moving part located at the right end of the cylinder body are relatively independent. The left end of the cylinder body is a moving component required for a plunger pump, and the right end of the cylinder body is a moving component required for another plunger pump. The left and right pumps share the distribution pair of the cylinder body and the distribution transmission shaft to perform the confluence work of suction and discharge of oil. Therefore, the relative phase angle requirements of the integrated double-sided cam guides on the left and right sides are not strict, and the position accuracy requirements are not high, thereby reducing the processing difficulty of the pump.

[0035] (2) The roller plunger assembly in the present invention is limited by a double contact method of large and small rollers and inner and outer circumferential surfaces. At the same time, the outer side surface of the U-shaped notch in the plunger is provided with an inner arc surface to maintain a mating contact with the outer circumferential surface of the small diameter of the integrated cam guide rail, thereby effectively limiting the roller plunger assembly in the circumferential direction to prevent self-rotation and ensuring the plunger's anti-overturning ability when subjected to the lateral force of the cam. There is no need to add additional retaining frame parts to limit the plunger assembly to maintain normal reciprocating motion.

[0036] (3) Without increasing the number of functional parts, the present invention can design the pump into a two-port pump with one oil inlet and one oil outlet, a three-port pump with one oil inlet (oil outlet) and two oil outlets (oil inlet), or a four-port pump with two oil inlets and two oil outlets, only by designing the cylinder body, the distribution transmission shaft structure and the flow channel. Compared with the traditional three-port pump and four-port pump, the structure is simpler and more compact, the integration is better, and the versatility is better. The two-port pump can better reduce the output flow pulsation of the pump by changing the number of plungers and the relative phase angle of the plungers on the left and right ends of the cylinder body; the three-port pump is an ideal solution for pump-controlled asymmetric cylinders. Two of the three ports are directly connected to the asymmetric cylinder, and the other port is connected to the oil tank, which reduces the use of valves and makes the whole system more integrated; the four-port pump arranges two plungers of different sizes on the cylinder body, shares the cylinder body and the distribution drive shaft, and realizes the simultaneous output of the flow of the two pumps. By changing the size of the two groups of plunger diameters, the displacement of the two pumps is different, and different flow outputs are achieved. Therefore, one of the pumps can be designed as a high-pressure and small flow pump, and the other pump can be designed as a low-pressure and large flow pump. By switching the reversing valve, the pump flow can be adjusted in stages to achieve the purpose of constant power control of the hydraulic cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 This is a schematic structural diagram of a two-port pump of a roller piston pump in an embodiment of the present application;

[0039] Figure 2 This is a schematic diagram of the structure of the cylinder body in the embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the structure of the distribution transmission shaft in the embodiment of the present application;

[0041] Figure 4 This is a schematic diagram of the structure of an integrated double-sided cam guide rail in an embodiment of the present application;

[0042] Figure 5 It is a schematic diagram of the assembly structure of the roller assembly in the embodiment of the present application;

[0043] Figure 6 This is a schematic diagram of the assembly structure of the roller assembly and the integrated cam guide rail in the embodiment of the present application;

[0044] Figure 7 This is a schematic diagram of the assembly of the cylinder body, the plunger and the distribution transmission shaft in the embodiment of the present application;

[0045] Figure 8 This is a schematic diagram of the movement direction and flow distribution principle in the embodiment of this application;

[0046] Fig. 9 This is a schematic diagram of the principle of a roller piston pump controlling a double-rod symmetrical cylinder in an embodiment of the present application;

[0047] Fig.10 This is a schematic diagram of the structure of a two-port pump using sixteen plungers in another embodiment of the present application;

[0048] Fig.11 This is a schematic diagram of the structure of a three-port pump in another embodiment of the present application.

[0049] Fig.12 This is a schematic structural diagram of a three-port pump cylinder in another embodiment of the present application;

[0050] Fig.13 This is a schematic structural diagram of a three-port pump distribution transmission shaft in another embodiment of the present application;

[0051] Fig.14This is a schematic diagram of the assembly of a three-port pump cylinder, a plunger and a distribution transmission shaft in another embodiment of the present application;

[0052] Fig.15 This is a schematic diagram of the movement direction and flow distribution principle of a three-port pump in another embodiment of the present application;

[0053] Fig.16 This is a schematic diagram of the principle of a three-port pump controlling a single-rod asymmetric cylinder in another embodiment of the present application;

[0054] Fig.17 This is a schematic diagram of the structure of a four-port pump in another embodiment of the present application.

[0055] Fig.18 This is a structural schematic diagram of a four-port pump cylinder in another embodiment of the present application;

[0056] Fig.19 This is a structural schematic diagram of a four-port pump flow distribution transmission shaft in another embodiment of the present application;

[0057] Fig. 20 for Fig.19 A cross-sectional view of a distribution groove of a distribution transmission shaft;

[0058] Fig.21 This is a schematic diagram of the assembly of a four-port pump cylinder, a plunger and a distribution transmission shaft in another embodiment of the present application;

[0059] Fig. 22 This is a schematic diagram of the movement direction and flow distribution principle of a four-port pump in another embodiment of the present application;

[0060] Fig.23 This is a schematic diagram of the principle of a double-rod symmetrical cylinder with a four-port pump under constant power control in another embodiment of the present application;

[0061] Fig.24 This is a schematic diagram of the principle of a four-port pump controlling two asymmetric cylinders in another embodiment of the present application. DETAILED DESCRIPTION

[0062] The present invention provides a roller plunger pump to solve the technical problems that the relative position accuracy of the cam guide rail installed in a split manner in the prior art hydraulic pump is insufficient, resulting in the roller rolling on it being unable to accurately contact, causing the pump to be stuck and stagnant, and making loud noises; at the same time, by changing the number of inlet and outlet oil flow channels of the distribution mechanism, the inlet and outlet oil flow rates are made inconsistent, thereby solving the technical problems that the prior art pump requires an additional valve group to control an asymmetric hydraulic cylinder and that the hydraulic cylinder cannot output constant power.

[0063] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0064] Example 1

[0065] like Figure 1 , 2 As shown in , 3, 4, 5, and 6, this embodiment provides a roller piston pump, which is a two-port pump and adopts a plug-in structure, including a pump end cover 10. In this embodiment, the direction along the central axis of the pump end cover 10 or parallel to the central axis of the pump end cover 10 is defined as the axial direction, the direction around the central axis of the pump end cover 10 is the circumferential direction, the direction of the cross-sectional diameter of the pump end cover 10 is the radial direction, and one end along the axial direction is the left end, and the other opposite end is the right end.

[0066] A cylinder body 4 coaxially arranged with the pump end cover 10 is provided on the right side of the pump end cover 10, and an axially distributed central through hole 106 is provided at the central position of the cylinder body 4, a distribution transmission shaft 5 is installed through the central through hole 106, and the distribution transmission shaft 5 is allowed to rotate along the circumferential direction in the central through hole 106 of the cylinder body 4 through the bearing limiters installed at the left and right end faces of the cylinder body 4, and the inner circular surface of the central through hole 106 of the cylinder body cooperates with the outer circular surface of the shoulder of the distribution transmission shaft 5 to form the axial distribution pair of the pump, and an oil seal 1 is installed at the central position of the pump end cover 10 to rotationally seal the distribution transmission shaft 5.

[0067] like Figure 2 As shown, the cylinder body 4 of the embodiment adopts an eight-plunger structure, and the left and right end faces of the cylinder body 4 are each provided with four plunger holes 105 that are evenly distributed in a circle parallel to the central axis. The four plunger holes 105 on the left side and the four plunger holes 105 on the right side are staggered along the axial projection, and the staggered angle is 45°.

[0068] Eight radial communication holes 201 evenly distributed around the circumference are opened at the center position of the central through hole 106 of the cylinder body to form a distribution window, and are communicated with the eight plunger holes 105 through the radial communication holes 201 and the plunger holes 105. The circumferential angle position of the radial communication holes 201 is the same as that of the plunger holes 105.

[0069] The outer circumferential surface of the cylinder body 4 is provided with two annular grooves, one of which is located on the left side of the center of the cylinder body and serves as the outer high-pressure flow channel 206 of the pump, and the other is located on the right side of the center of the cylinder body and serves as the outer low-pressure flow channel 306 of the pump; the inner surface of the central through hole 106 of the cylinder body is also provided with two annular grooves, one of which is arranged on the left side of the central through hole of the cylinder body and serves as the inner high-pressure flow channel 204 of the pump, and the other is arranged on the right side of the central through hole of the cylinder body and serves as the inner low-pressure flow channel 304 of the pump; the inner and outer high-pressure flow channels 204, 206, and the inner and outer low-pressure flow channels 304, 306 respectively penetrate through radial through holes 205, 305 uniformly distributed circumferentially between the two plunger holes;

[0070] The shoulder of the two-port pump distribution transmission shaft 5 is provided with two high-pressure and low-pressure annular flow channels 203 and 303 corresponding to the high-pressure flow channel 204 and the internal low-pressure flow channel 304 in the cylinder body, and four V-shaped distribution grooves evenly distributed along the circumferential direction are provided in the middle position between the high-pressure and low-pressure annular flow channels 203 and 303, two of which are high-pressure distribution grooves 202 and the other two are low-pressure distribution grooves 302. The high-pressure and low-pressure distribution grooves 202 and 302 are staggered in the circumferential direction, and the high-pressure distribution groove 202 communicates with the high-pressure annular flow channel 203, and the low-pressure distribution groove 302 communicates with the low-pressure annular flow channel 303;

[0071] The integrated double-sided cam guide 3 is provided with a large circular curved surface 101 and a small circular curved surface 102, and the large and small circular curved surfaces 101 and 102 both have two high points H1 and two low points H2, and the four high points H1 and low points H2 are staggered and evenly distributed in the circumferential direction, and the high point H1 of the large circular curved surface always faces the low point H2 of the small circular curved surface, and the surface change law between any high points H1 and low points H2 of the large and small circular curved surfaces 101 and 102 is consistent, and as a preferred embodiment, the surface change law should adopt the surface of equal acceleration and equal deceleration motion law. The integrated double-sided cam guide 3 is installed at both ends of the distribution transmission shaft 5 through nuts 2, and in the direction of the installation position, the highest point H1 of the left integrated double-sided cam guide 3 always faces the highest point H1 of the right integrated double-sided cam guide 3.

[0072] The roller plunger assembly includes a plunger 9 with a U-shaped notch at one end, a large roller 7, a small roller 6 and a roller shaft 8. The large roller 7 is arranged in the U-shaped notch of the plunger 9 through the roller shaft 8, and the small roller 6 is arranged on one side of the end face of the U-shaped notch of the plunger through the roller shaft 8. The side of the plunger 9 where the small roller 6 is installed is provided with an arc-shaped curved surface 104.

[0073] The large roller 7 and the small roller 6 are arranged between the large and small circular surfaces 101 and 102 of the integrated double-sided cam guide 3. The large roller 7 is in contact with and fits the large circular surface 101, and the small roller 6 is in contact with and fits the small circular surface 102. Furthermore, in order to better improve the transmission accuracy, it is preferred that the small roller 6 adopts a roller with an outer ring with elastic plastic deformation, increases the preload force by the deformation, and eliminates the gap between the roller and the surface.

[0074] The arc-shaped surface 104 of the plunger 9 contacts and cooperates with the outer circumferential surface 103 of the small circumferential surface of the integrated double-sided cam guide rail, ensuring that the plunger 9 does not experience self-rotation movement; the circular plunger part of the plunger 9 is placed in the plunger hole 105 of the cylinder body 4, and is enclosed with the cylinder body 4 to form the suction and discharge volume chambers Va and Vb of the pump.

[0075] The integrated double-sided cam guide 3 rotates under the drive of the distribution transmission shaft 5, forcing the large roller 7 and the small roller 6 to rotate and roll on the circular surface, and the change in the stroke of the large and small circular surfaces drives the plunger 9 to reciprocate axially, causing the volume of the suction and discharge volume chambers Va and Vb of the pump to change, and the suction and discharge of oil is realized through the shaft distribution pair.

[0076] like Figure 7 The figure shows an assembly diagram of the cylinder body 4, the distribution transmission shaft 5 and the plunger 9, wherein the plunger 9 and the cylinder body 4 form closed volume chambers Va and Vb; the central through hole 106 of the cylinder body 4 cooperates with the outer cylindrical shoulder surface of the distribution transmission shaft 5 to form an axial distribution pair, the high-pressure annular flow channel 203 on the distribution transmission shaft 5 cooperates with the high-pressure annular flow channel 204 on the cylinder body 4 to form a closed high-pressure channel, and communicates with the external high-pressure flow channel 206 through the radial through hole 205, the low-pressure annular flow channel 303 on the distribution transmission shaft 5 cooperates with the low-pressure annular flow channel 304 on the cylinder body 4 to form a closed low-pressure channel, and communicates with the external low-pressure flow channel 306 through the radial through hole 305.

[0077] like Figure 7 , 8 As shown in the figure, its specific working and distribution principle is: when the distribution transmission shaft 5 starts to rotate driven by external force, the movement directions of the two adjacent plungers on the right end face of the cylinder body 4 are necessarily opposite due to the curved surface law of the integrated cam guide 3, and the displacement change law is the same. When the plunger of the Va chamber starts to move to the left, the volume of the Va chamber becomes smaller and the oil starts to be discharged. At this time, the cylinder body distribution window 201 communicates with the V-shaped distribution groove 202 of the distribution transmission shaft 5, and the oil passes through the Va chamber. →201→202→203→204→205→206 and discharged to the outer high-pressure annular flow channel 206; at the same time, the plunger of the Vb chamber begins to move to the right, the volume of the Va chamber increases, and it begins to absorb oil. At this time, the cylinder body distribution window 201 communicates with the V-shaped distribution groove 302 of the distribution transmission shaft 5, and the oil is sucked from the outer low-pressure annular flow channel 306 through the path of 306→305→304→303→302→201→Vb. According to this rule, the remaining plungers 9 will also start to absorb and discharge oil as the distribution transmission shaft 5 rotates, and since the inhaled oil and the discharged oil are theoretically completely equal, if Fig. 9 As shown in the schematic diagram, it can be used to directly control a double-rod symmetrical cylinder.

[0078] Example 2

[0079] This embodiment provides a roller piston pump, wherein the roller piston pump is a two-port pump using sixteen plungers.

[0080] like Fig.10As shown, the left and right end surfaces of the cylinder body 4 of this embodiment are provided with eight plunger holes 105 which are evenly distributed in a circle parallel to the central axis, and the eight plunger holes 105 on the left side and the eight plunger holes 105 on the right side are coaxially arranged in parallel along the axial projection, with a staggered angle of 0°, and the structural features and working principles of the remaining components are exactly the same as those of embodiment 1. The sixteen plungers improve the space utilization of the pump, and at the same time make the output flow pulsation of the pump smaller, which is more suitable for large flow and low pressure applications.

[0081] Example 3

[0082] This embodiment provides a roller piston pump, wherein the roller piston pump is a three-port pump.

[0083] like Fig.11 , 12 As shown in 13, the three-port pump embodiment adopts an eight-plunger structure, and the left and right end faces of the cylinder body 4 are provided with four plunger holes 105 which are evenly distributed in a circle parallel to the central axis. The four plunger holes 105 on the left side and the four plunger holes 105 on the right side are staggered along the axial projection, and the staggered angle is 45°.

[0084] The four plunger holes 105 on the left end face of the cylinder body 4 are all provided with radial communication holes 201 facing the central axis of the cylinder body 4, which are communicated with the central through hole 106 of the cylinder body to form a distribution window; the four plunger holes 105 on the right end face of the cylinder body 4 are all provided with radial communication holes 401 facing the central axis of the cylinder body 4, which are communicated with the central through hole 106 of the cylinder body to form a distribution window; the radial communication holes 201, 401 are at the same circumferential angular position as the plunger holes 105.

[0085] The outer circumferential surface of the cylinder body 4 is provided with three annular grooves, which are, from left to right, the first high-pressure outer annular flow channel 206, the second low-pressure outer annular flow channel 306, and the third high-pressure outer annular flow channel 406; the inner surface of the central through hole 106 of the cylinder body is also provided with three annular grooves corresponding to the outer circumferential surface of the cylinder body 4, which are, from left to right, the first high-pressure inner annular flow channel 204, the second low-pressure inner annular flow channel 304, and the third high-pressure inner annular flow channel 404; the one-to-one corresponding inner and outer annular grooves are uniformly distributed circumferentially in the radial direction between the two plunger holes 105 The through holes 205, 305, and 405 are connected through and in communication; four radial holes 201 evenly distributed on the circumference are opened between the first high-pressure inner annular flow channel 204 and the second low-pressure inner annular flow channel 304 of the central through hole 106 of the cylinder body, which are connected through and in communication with the four plunger holes 105 on the left end face of the cylinder body 4 to form a left distribution window; four radial holes 401 evenly distributed on the circumference are opened between the second low-pressure inner annular flow channel 304 and the third high-pressure inner annular flow channel 404 of the central through hole 106 of the cylinder body, which are connected through and in communication with the four plunger holes 105 on the right end face of the cylinder body 4 to form a right distribution window;

[0086] The shoulder of the three-port pump distribution transmission shaft 5 is provided with three annular grooves from left to right, corresponding one to one with the annular grooves in the center hole of the cylinder body, which are respectively the first high-pressure annular flow channel 203, the second low-pressure annular flow channel 303, and the third high-pressure annular flow channel 403; four V-shaped distribution grooves uniformly distributed along the axial circumference are provided between the first high-pressure annular flow channel 203 and the second low-pressure annular flow channel 303, which are used to communicate with the left distribution window of the cylinder body, two of which are high-pressure distribution grooves 202, and the other two are low-pressure distribution grooves 302. The high and low-pressure distribution grooves 202, 302 are staggered in the circumferential direction, and the high-pressure distribution groove 202 communicates with the first high-pressure annular flow channel 203, and the low-pressure distribution groove 302 communicates with the second low-pressure annular flow channel The second low-pressure annular flow channel 303 communicates with the third high-pressure annular flow channel 403; four V-shaped flow distribution grooves are evenly distributed along the axial circumference between the second low-pressure annular flow channel 303 and the third high-pressure annular flow channel 403, which are used to communicate with the right flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves 502, and the other two are low-pressure flow distribution grooves 402. The high-pressure and low-pressure flow distribution grooves 502 and 402 are staggered in the circumferential direction, and the high-pressure flow distribution groove 502 communicates with the third high-pressure annular flow channel 403, and the low-pressure flow distribution groove 402 communicates with the second low-pressure annular flow channel 303; the eight V-shaped flow distribution grooves are arranged symmetrically in space with the second low-pressure annular flow channel 303 as the mirror center, and the left high-pressure flow distribution groove 202 is arranged axially parallel to the right high-pressure flow distribution groove 502;

[0087] like Fig.14 The figure shows an assembly diagram of the cylinder body 4, the distribution transmission shaft 5 and the plunger 9 of the three-port pump. The plunger 9 and the cylinder body 4 form closed volume chambers Va, Vb and Vc; the central through hole 106 of the cylinder body 4 cooperates with the outer cylindrical shoulder surface of the distribution transmission shaft 5 to form an axial distribution pair; the annular grooves 203, 303, 403 on the distribution transmission shaft 5 are respectively connected with 204, 304, 404 on the central through hole 106 of the cylinder body in the circumferential direction to form a closed annular flow channel, and are communicated with the outer flow channels 206, 306, 406 through radial through holes 205, 305, 405 respectively.

[0088] like Fig.14 , 15Its specific working and distribution principle are shown as follows: when the distribution transmission shaft 5 starts to rotate driven by an external force, the movement directions of the two adjacent plungers on the right end face of the cylinder body 4 are necessarily opposite due to the curved surface law of the integrated cam guide 3, and the displacement change law is the same. When the plunger of the Va chamber starts to move to the left, the volume of the Va chamber becomes smaller and the oil starts to be discharged. At this time, the cylinder body distribution window 201 communicates with the V-shaped high-pressure distribution groove 202 of the distribution transmission shaft 5, and the oil is discharged to the first high-pressure outer annular flow channel 206 through the path of Va→201→202→203→204→205→206; at the same time, the plunger of the Vb chamber starts to move to the right, The volume of the Va chamber increases and it starts to absorb oil. At this time, the cylinder body distribution window 201 communicates with the V-shaped low-pressure distribution groove 302 of the distribution transmission shaft 5, and the oil is sucked from the second low-pressure inner annular flow channel 306 through the path of 306→305→304→303→302→201→Vb; at the same time, the plunger of the Vc chamber also starts to move to the right, the volume of the Vc chamber decreases, and it starts to discharge oil. At this time, the cylinder body distribution window 401 communicates with the V-shaped high-pressure distribution groove 502 of the distribution transmission shaft 5, and the oil is discharged to the third high-pressure outer annular flow channel 406 through the path of Vc→401→502→403→404→405→406.

[0089] According to this rule, the other plungers 9 will also start to suck and discharge oil continuously as the distribution transmission shaft 5 rotates, and since the oil sucked from the second low-pressure outer annular flow channel 306 is eventually diverted to the first high-pressure outer annular flow channel 206 and the third high-pressure outer annular flow channel 406 for discharge, Fig.16 As shown in the schematic diagram, the second low-pressure outer annular flow channel 306 can be connected to the rodless chamber of the hydraulic cylinder, and the first high-pressure outer annular flow channel 206 and the third high-pressure outer annular flow channel 406 can be connected to the rod chamber and the external oil tank respectively to directly control the single-rod hydraulic cylinder.

[0090] Example 4

[0091] This embodiment provides a roller piston pump, wherein the roller piston pump is a four-port pump.

[0092] like Fig.17 , 18 As shown in Figures 19 and 20, the four-port pump embodiment adopts a sixteen-plunger structure. The left and right end faces of the cylinder body 4 are provided with eight plunger holes that are evenly distributed in a circle parallel to the central axis, four of which are large plunger holes 108 and the other four are small plunger holes 107. The large plunger holes and the small plunger holes are staggered in the circumferential direction; the small plunger hole 107 on the left side and the large plunger hole 108 on the right side are coaxially arranged along the axial direction, and the staggered angle is 0°.

[0093] The eight small plunger holes 107 on the left and right side end faces of the cylinder body 4 are all provided with radial communication holes 201 facing the central axis of the cylinder body 4, which are communicated with the central through hole 106 of the cylinder body to form a distribution window; the four large plunger holes 108 on the left side end face of the cylinder body 4 are all provided with radial communication holes 701 facing the central axis of the cylinder body 4, which are communicated with the central through hole 106 of the cylinder body to form a distribution window; the four large plunger holes 108 on the right side end face of the cylinder body 4 are all provided with radial communication holes 601 facing the central axis of the cylinder body 4, which are communicated with the central through hole 106 of the cylinder body to form a distribution window; the radial communication holes 601, 701 are at the same circumferential angle relative to the plunger holes 107, 108.

[0094] The outer circumferential surface of the cylinder body 4 is provided with four annular grooves, which serve as annular flow channels for the oil inlet and outlet of the pump, from left to right, namely, the first low-pressure outer annular flow channel 708, the second high-pressure outer annular flow channel 206, the third low-pressure outer annular flow channel 306, and the fourth high-pressure outer annular flow channel 608; the inner surface of the central through hole 106 of the cylinder body is also provided with four annular grooves corresponding to the outer circumferential surface of the cylinder body, from left to right, namely, the first low-pressure inner annular flow channel 706, the second high-pressure inner annular flow channel 204, the third low-pressure inner annular flow channel 304, and the fourth high-pressure inner annular flow channel 606; the one-to-one corresponding inner and outer annular grooves are connected through radial through holes 707, 205, 305, and 607 uniformly distributed between the two plunger holes; the first low-pressure inner annular flow channel 706 and the second high-pressure inner annular flow channel 204 of the central through hole 106 of the cylinder body are connected to each other. Four radial holes 701 evenly distributed around the circumference are opened between them, which are communicated with the four large plunger holes 108 on the left end face of the cylinder body 4 to form a left distribution window for distributing flow to the large plunger 108 on the left end face; eight radial holes 201 evenly distributed around the circumference are opened between the second high-pressure inner annular flow channel 204 and the third low-pressure inner annular flow channel 304 of the central through hole 106 of the cylinder body, which are communicated with the eight small plunger holes 107 on the left and right end faces of the cylinder body 4 to form a middle distribution window for distributing flow to the small plungers 107 on the left and right end faces; four radial holes 601 evenly distributed around the circumference are opened between the third low-pressure inner annular flow channel 304 and the fourth high-pressure inner annular flow channel 606 of the central through hole 106 of the cylinder body, which are communicated with the four large plunger holes 108 on the right end face of the cylinder body 4 to form a right distribution window for distributing flow to the large plunger 108 on the right end face;

[0095] The shoulder of the four-port pump distribution transmission shaft 5 is provided with four annular grooves from left to right, corresponding to the annular grooves in the center hole of the cylinder body, which are respectively the first low-pressure annular flow channel 705, the second high-pressure annular flow channel 203, the third low-pressure annular flow channel 303, and the fourth high-pressure annular flow channel 605;

[0096] The shoulder core of the distribution transmission shaft 5 is provided with four inner flow channels evenly distributed around the circumference, of which two are high-pressure inner flow channels 604 and the other two are low-pressure inner flow channels 704. The high-pressure and low-pressure inner flow channels 604 and 704 are staggered in the circumferential direction, and the high-pressure inner flow channel 604 is connected to the fourth high-pressure annular flow channel 605, and the low-pressure inner flow channel 704 is connected to the first low-pressure annular flow channel 705.

[0097] Four V-shaped flow distribution grooves evenly distributed along the axial circumference are provided between the first low-pressure annular flow channel 705 and the second high-pressure annular flow channel 203, which are used to communicate with the left flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves 602, and the other two are low-pressure flow distribution grooves 702. The high-pressure and low-pressure flow distribution grooves 602, 702 are staggered in the circumferential direction, and the high-pressure flow distribution groove 602 is connected to the fourth high-pressure annular flow channel 605 through the high-pressure inner flow channels 603, 604 of the flow distribution transmission shaft, and the low-pressure flow distribution groove 702 is connected to the first low-pressure annular flow channel 705 through the low-pressure inner flow channels 703, 704 of the flow distribution transmission shaft;

[0098] Four V-shaped distribution grooves evenly distributed along the axial circumference are provided between the third low-pressure annular flow channel 303 and the fourth high-pressure annular flow channel 605, which are used to communicate with the right distribution window of the cylinder body, two of which are high-pressure distribution grooves 602, and the other two are low-pressure distribution grooves 702. The high and low-pressure distribution grooves 602, 702 are staggered in the circumferential direction, and the high-pressure distribution groove 602 is connected with the fourth high-pressure annular flow channel 605 through the high-pressure inner flow channels 603, 604 of the distribution transmission shaft, and the low-pressure distribution groove 702 is connected with the first low-pressure annular flow channel 705 through the low-pressure inner flow channels 703, 704 of the distribution transmission shaft; and the high-pressure distribution groove 602 located between the first low-pressure annular flow channel 705 and the second high-pressure annular flow channel 203 and the high-pressure distribution groove 602 located between the third low-pressure annular flow channel 303 and the fourth high-pressure annular flow channel 605 are arranged in parallel in the axial direction;

[0099] Four V-shaped flow distribution grooves evenly distributed along the axial circumference are provided between the second high-pressure annular flow channel 203 and the third low-pressure annular flow channel 303, which are used to communicate with the middle flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves 202, and the other two are low-pressure flow distribution grooves 302. The high-pressure and low-pressure flow distribution grooves 202 and 302 are staggered in the circumferential direction, and the high-pressure flow distribution groove 202 communicates with the second high-pressure annular flow channel 203, and the low-pressure flow distribution groove 302 communicates with the second low-pressure annular flow channel 303; and the high-pressure flow distribution groove 202 located between the second high-pressure annular flow channel 203 and the third low-pressure annular flow channel 303 and the high-pressure flow distribution groove located between the third low-pressure annular flow channel 303 and the fourth high-pressure annular flow channel 605 are arranged in parallel in the axial direction;

[0100] like Fig.21 The figure shows an assembly diagram of the cylinder body 4, the distribution transmission shaft 5 and the plunger 10 of a four-port pump. As shown in the figure, the plunger 10 and the cylinder body 4 form closed volume chambers Va, Vb, Vc and Vd; the central through hole 106 of the cylinder body 4 cooperates with the outer cylindrical shoulder surface of the distribution transmission shaft 5 to form an axial distribution pair, and the annular grooves 705, 203, 303, 605 on the distribution transmission shaft 5 are respectively connected with the 706, 204, 304, 606 on the central through hole 106 of the cylinder body in the circumferential direction to form a closed annular flow channel, and are communicated with the outer flow channels 708, 206, 306, 608 through radial through holes 707, 205, 305, 607 respectively.

[0101] like Fig.21 , 22 As shown, its specific working and distribution principle is: when the distribution transmission shaft 5 starts to rotate driven by external force, the movement directions of the two adjacent plungers 12 on the right end face of the cylinder body 4 must be opposite due to the curved surface law of the integrated cam guide 3, and the displacement change law is the same. The coaxial large plunger 12 and small plunger 11 on the left and right side end faces of the cylinder body must also move in opposite directions and have the same displacement change law. When the small plunger 11 of the Va chamber starts to move to the right, the volume of the Va chamber becomes smaller and starts to discharge oil. At this time, the cylinder body distribution window 201 and the V-shaped distribution transmission shaft 5 The high-pressure distribution groove 202 is communicated, and the oil is discharged to the second high-pressure outer annular flow channel 206 through the path of Va→201→202→203→204→205→206; at the same time, the small plunger 11 of the Vb chamber begins to move to the left, the volume of the Va chamber increases, and it begins to absorb oil. At this time, the cylinder body distribution window 201 communicates with the V-shaped low-pressure distribution groove 302 of the distribution drive shaft 5, and the oil is sucked from the third low-pressure outer annular flow channel 306 through the path of 306→305→304→303→302→201→Vb.

[0102] At the same time, the large plunger 12 of the Vc chamber begins to move to the left, the volume of the Vc chamber decreases, and the oil begins to be discharged. At this time, the cylinder body distribution window 601 communicates with the V-shaped high-pressure distribution groove 602 of the distribution transmission shaft 5, and the oil is discharged to the fourth high-pressure outer annular flow channel 608 through the path of Vc→601→602→603→604→605→606→607→608; the large plunger 12 of the Vd chamber begins to move to the right, the volume of the Vd chamber increases, and the oil begins to be absorbed. At this time, the cylinder body distribution window 701 communicates with the V-shaped low-pressure distribution groove 702 of the distribution transmission shaft 5, and the oil is sucked from the first outer low-pressure annular flow channel 708 through the path of 708→707→706→705→704→703→702→701→Vb.

[0103] According to this rule, the other large plungers 12 and small plungers 11 of the four-port pump will also start to continuously suck and discharge oil as the distribution transmission shaft 5 rotates. Among them, the eight small plungers 12 rely on the distribution window 201 and the high and low pressure distribution grooves 202 and 302 to pump a small flow of oil from the third low-pressure outer annular flow channel 306 to the second high-pressure outer annular flow channel 206; and the eight large plungers 11 rely on the distribution windows 601, 701 and the high and low pressure distribution grooves 602 and 702 to pump a large flow of oil from the first low-pressure outer annular flow channel 708 to the fourth high-pressure outer annular flow channel 608. Conversely, by changing the positions of the large and small plungers, the oil pumped from the third low-pressure outer annular flow channel 306 to the second high-pressure outer annular flow channel 205 can be designed to have a large flow rate, while the oil pumped from the first low-pressure outer annular flow channel 708 to the fourth high-pressure outer annular flow channel 608 can be designed to have a small flow rate.

[0104] The four-port pump relies on a flow distribution transmission shaft 5 to achieve two different flow rates. Fig.23 As shown in the schematic diagram, the pump with a small plunger can be designed as a small-flow high-pressure pump, while the pump with a large plunger can be designed as a large-flow low-pressure pump. They are connected to the symmetrical cylinders respectively to achieve constant power output control. When the hydraulic cylinder is running without load, it requires a large flow and low pressure. Therefore, the two pumps work and output at the same time to increase the output speed of the hydraulic cylinder. When the hydraulic cylinder needs to provide a larger load, it requires a small flow and high pressure. By switching the reversing valve or the built-in pressure pilot valve, the inlet and outlet of the large-flow pump are short-circuited, and the small-displacement pump provides pressure output to achieve the function.

[0105] In addition, if Fig.24 As shown in the schematic diagram, the four-port pump can also connect the large-flow inlet and outlet oil to the rodless chambers of the two hydraulic cylinders respectively, and connect the small-flow inlet and outlet to the rod chambers respectively, directly and synchronously controlling the two asymmetric hydraulic cylinders, providing a new solution for the synchronous control of hydraulic cylinders.

[0106] The directional terms such as outer, middle, inner, high, low, in, out, suction, and discharge mentioned or may be mentioned in this specification are defined relative to the structures and functions shown in the drawings. They are relative concepts and may change accordingly according to different locations and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0107] The above is only a preferred embodiment of the present application, and is not any formal or substantial limitation to the present application. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be regarded as the protection scope of the new invention. Any technician familiar with this profession can make some changes, modifications and evolutions of the technical content disclosed above without departing from the spirit and scope of the present application, which are equivalent embodiments of the present application; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the substantial technology of the present application are still within the scope of the technical solution of the present application.

Claims

1. A roller piston pump, comprising a pump end cover (10), wherein the direction along the central axis of the pump end cover or parallel to the central axis of the pump end cover (10) is defined as the axial direction, the direction around the central axis of the pump end cover (10) is defined as the circumferential direction, and one end along the axial direction is defined as the left end, and the other end opposite to the axial direction is defined as the right end; the direction toward the middle of the central axis is defined as the inward direction, and the direction away from the central axis is defined as the outward direction; A pump core is provided on the right side of the pump end cover (10), and the middle part of the pump core is a cylinder body (4) coaxially arranged with the pump end cover (10). An axially distributed central through hole (106) is provided at the central position of the cylinder body (4), and a distribution transmission shaft (5) is installed through the central through hole (106). The distribution transmission shaft (5) is allowed to rotate circumferentially in the central through hole (106) of the cylinder body through bearing limiters installed on the left and right end faces of the cylinder body (4). The inner circumferential surface of the central through hole (106) of the cylinder body cooperates with the outer circumferential surface of the shoulder of the distribution transmission shaft (5) to form the shaft distribution pair of the pump; the characteristics are as follows: An even number of plunger holes are evenly arranged on the left and right end faces of the cylinder body (4) along the circumferential direction of the central axis, and the axial projection of the plunger hole on the left end face of the cylinder body (4) and the axial projection of the plunger hole on the right end face of the cylinder body (4) are alternately evenly distributed or coaxially distributed; the plunger (9) of the roller plunger assembly is slidably arranged in the plunger hole (105), and the plunger hole and the plunger end face enclose a piston cavity; the large roller (7) of the roller plunger assembly rolls on the large circumferential curved surface (101), and the small roller (6) of the roller plunger assembly rolls on the small circumferential curved surface (102), so that the plunger reciprocates and changes the volume of the piston cavity; The inner circumferential surface of the central through hole (106) of the cylinder body is provided with radial through holes (201) which are connected to the plunger hole (105) on the left end surface of the cylinder body and the plunger hole (105) on the right end surface of the cylinder body. The radial through holes (201) are evenly distributed along the circumference of the axis and serve as flow distribution windows of the cylinder body (4). The number of radial through holes (201) is equal to the number of plunger holes (105). The outer circumferential surface of the cylinder body (4) is provided with outer annular grooves (206) and (306) which serve as oil inlet and outlet flow channels. The number of the oil inlet and outlet annular flow channels is equal to the number of inlets and outlets of the pump. The inner circumferential surface of the central through hole (106) of the cylinder body is also provided with inner annular grooves (204) and (304) which are the same in number as the outer annular grooves on the outer circumferential surface. The inner and outer annular grooves are communicated through radial through holes (205) and (305) distributed between the plunger holes. The distribution transmission shaft (5) has a shoulder, and the left and right ends of the shoulder are respectively provided with extension shafts, and the left and right extension shafts are respectively fixedly mounted with an integrated double-sided cam guide rail (3), and the high point H1 of the left integrated double-sided cam guide rail (3) is always facing the high point H1 of the right integrated double-sided cam guide rail; the left extension shaft has an extension part, which serves as an introduction connection for a power source; The shoulder of the distribution transmission shaft (5) is provided with annular channels (203) and (303) of the same number as the annular oil flow channels of the cylinder body (4); the outer circumferential surface of the distribution transmission shaft (5) located between the annular flow channels (203) and (303) is provided with V-shaped distribution grooves (202) and (302) along the axis, connecting the annular channels (203) and (303) with the cylinder body distribution window (201); a relief groove (109) is provided on the generatrix formed by the V-shaped distribution grooves (202) and (302) and the outer circumferential surface of the shoulder of the distribution transmission shaft (5); the arrangement position of the relief groove (109) and the position of the cylinder body distribution window (201) are on the same radial cross section, The distance between the sharpest points of two adjacent unloading grooves (109) along the circumferential direction is consistent with the width of the cylinder flow distribution window (201) along the circumferential direction. With the rotation of the flow distribution transmission shaft (5), the V-shaped flow distribution grooves (202), (302) and the unloading grooves (109) and the cylinder flow distribution window (201) will periodically intersect and communicate with each other, so that the cylinder plunger hole (105) and the annular channel (203), (303) of the flow distribution transmission shaft are communicated, and while the oil in the plunger hole (105) is accurately distributed to the cylinder oil inlet and outlet annular flow channels (206), (306), the backflow of the output flow and the output pressure fluctuation are reduced; The one-piece double-sided cam guide rail (3) is provided with a large circular curved surface (101) and a small circular curved surface (102) relative to each other. The small circular curved surface (102) is located inside the large circular curved surface (3). The large circular curved surface (101) and the small circular curved surface (102) have two high points H1 and two low points H2. The four high and low points H1 and H2 are evenly distributed in a staggered manner in the circumferential direction. The high point H1 of the large circular curved surface (101) always faces the low point H2 of the small circular curved surface (102), and the low point H2 of the large circular curved surface (101) always faces the high point H1 of the small circular curved surface (102). The surface change rules between any high and low points H1 and H2 of the large circular curved surface (101) and the small circular curved surface (102) remain consistent.

2. A roller piston pump according to claim 1, characterized in that: The roller plunger assembly comprises a plunger (9) with a U-shaped notch at one end, a large roller (7), a small roller (6) and a roller shaft (8); the large roller (7) is arranged in the U-shaped notch of the plunger (9) through the roller shaft (8); and the small roller (6) is arranged on one side of the end face of the U-shaped notch of the plunger through the roller shaft (8).

3. A roller piston pump as claimed in claim 2, characterized in that: The small roller (6) is a roller with an outer ring having elastic plastic deformation, and the preload force is increased by the deformation amount, thereby eliminating the gap between the roller and the curved surface.

4. A roller piston pump according to claim 1, characterized in that: The surface variation rules of the large circular curved surface (101) and the small circular curved surface (102) adopt equal acceleration and equal deceleration motion law curves.

5. A roller piston pump according to claim 1, characterized in that: The shape of the unloading groove (109) is a triangular groove or an arcuate groove.

6. A roller piston pump according to claim 1, characterized in that: The number of the even-numbered plunger holes (105) on the cylinder body (4) is eight or sixteen, and correspondingly, the number of the cylinder body flow distribution windows (201) is consistent with the number of the plunger holes (105).

7. A roller piston pump according to claim 1, characterized in that: The invention is a two-port pump, wherein the left and right end surfaces of the cylinder body (4) are respectively provided with four plunger holes (105) evenly distributed along the circumferential direction of the central axis, and the middle position of the central through hole (106) of the cylinder body is provided with eight radial holes (201) evenly distributed around the circumference, four of which are in communication with the plunger (105) on the left end surface of the cylinder body (4), and four of which are in communication with the plunger (105) on the right end surface of the cylinder body (4); the outer circumferential surface of the cylinder body (4) is provided with two annular grooves, one of which is located on the left side of the center of the cylinder body and serves as an outer high-pressure flow channel (206) of the pump, and the other is located on the left side of the center of the cylinder body and serves as an outer high-pressure flow channel (206) of the pump. The right side of the center of the cylinder body serves as the outer low-pressure flow channel (306) of the pump; the inner surface of the central through hole (106) of the cylinder body is also provided with two annular grooves, one of which is arranged on the left side of the central through hole of the cylinder body and serves as the inner high-pressure flow channel (204) of the pump, and the other is arranged on the right side of the central through hole of the cylinder body and serves as the inner low-pressure flow channel (304) of the pump; the inner and outer high-pressure flow channels (204), (206), and the inner and outer low-pressure flow channels (304), (306) respectively penetrate through radial through holes (205), (305) uniformly distributed circumferentially between the two plunger holes; The flow distribution transmission shaft (5) has two high-pressure and low-pressure annular flow channels (203) and (303) on its shoulder, which correspond to the high-pressure flow channel (204) and the internal low-pressure flow channel (304) in the cylinder body. Four V-shaped flow distribution grooves evenly distributed along the circumferential direction are provided at the middle position between the high-pressure and low-pressure annular flow channels (203) and (303), two of which are high-pressure flow distribution grooves (202) and the other two are low-pressure flow distribution grooves (302). The high-pressure and low-pressure flow distribution grooves (202) and (302) are staggeredly distributed in the circumferential direction, and the high-pressure flow distribution groove (202) communicates with the high-pressure annular flow channel (203), and the low-pressure flow distribution groove (302) communicates with the low-pressure annular flow channel (303).

8. A roller piston pump according to claim 1, characterized in that: The invention is a three-port pump, wherein the left and right end surfaces of the cylinder body (4) are respectively provided with four plunger holes (105) evenly distributed along the circumferential direction of the central axis; the outer circumferential surface of the cylinder body is provided with three annular grooves, which are, from left to right, a first high-pressure outer annular flow channel (206), a second low-pressure outer annular flow channel (306), and a third high-pressure outer annular flow channel (406); the inner surface of the central through hole (106) of the cylinder body is also provided with three annular grooves corresponding to the outer circumferential surface of the cylinder body (4), which are, from left to right, a first high-pressure inner annular flow channel (204), a second low-pressure inner annular flow channel (304), and a third high-pressure inner annular flow channel (404); the one-to-one corresponding inner and outer annular grooves are evenly distributed along the circumference. The radial through holes (205), (305), (405) between the two plunger holes (105) are connected through and in communication; four radial holes (201) evenly distributed around the circumference are opened between the first high-pressure inner annular flow channel (204) and the second low-pressure inner annular flow channel (304) of the central through hole (106) of the cylinder body, which are connected through and in communication with the four plunger holes (105) on the left end face of the cylinder body (4) to form a left flow distribution window; four radial holes (401) evenly distributed around the circumference are opened between the second low-pressure inner annular flow channel (304) and the third high-pressure inner annular flow channel (404) of the central through hole (106) of the cylinder body, which are connected through and in communication with the four plunger holes (105) on the right end face of the cylinder body (4) to form a right flow distribution window; The shoulder of the distribution transmission shaft (5) is provided with three annular grooves from left to right, corresponding to the annular grooves in the center hole of the cylinder body one by one, and are respectively the first high-pressure annular flow channel (203), the second low-pressure annular flow channel (303), and the third high-pressure annular flow channel (403); four V-shaped distribution grooves evenly distributed along the axial circumference are provided between the first high-pressure annular flow channel (203) and the second low-pressure annular flow channel (303), which are used to communicate with the left distribution window of the cylinder body, two of which are high-pressure distribution grooves (202), and the other two are low-pressure distribution grooves (302); the high and low-pressure distribution grooves (202) and (302) are staggered in the circumferential direction, and the high-pressure distribution groove (202) communicates with the first high-pressure annular flow channel (203), and the low-pressure distribution groove (302) communicates with the second low-pressure annular flow channel. (303); four V-shaped flow distribution grooves are evenly distributed along the axial circumference between the second low-pressure annular flow channel (303) and the third high-pressure annular flow channel (403), which are used to communicate with the right flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves (502), and the other two are low-pressure flow distribution grooves (402). The high and low-pressure flow distribution grooves (502) and (402) are staggered in the circumferential direction, and the high-pressure flow distribution groove (502) communicates with the third high-pressure annular flow channel (403), and the low-pressure flow distribution groove (402) communicates with the second low-pressure annular flow channel (303); the eight V-shaped flow distribution grooves are arranged in a mirror-symmetrical manner with the second low-pressure annular flow channel (303) as the mirror center in terms of spatial position, and the left high-pressure flow distribution groove (202) and the right high-pressure flow distribution groove (502) are arranged axially parallel.

9. A roller piston pump according to claim 1, characterized in that: The invention is a four-port pump, wherein the left and right end surfaces of the cylinder body (4) are respectively evenly arranged with eight plunger holes along the circumferential direction of the central axis, four of which are large plunger holes (108) and the other four are small plunger holes (107), and the large and small plunger holes (108) and (107) are staggeredly distributed in the circumferential direction; the outer circumferential surface of the cylinder body (4) is provided with four annular grooves, which are, from left to right, a first low-pressure outer annular flow channel (708), a second high-pressure outer annular flow channel (206), a third low-pressure outer annular flow channel (306), and a fourth high-pressure outer annular flow channel (407). The inner surface of the central through hole (106) of the cylinder body is also provided with four annular grooves corresponding to the outer circumferential surface of the cylinder body, which are, from left to right, the first low-pressure inner annular flow channel (706), the second high-pressure inner annular flow channel (204), the third low-pressure inner annular flow channel (304), and the fourth high-pressure inner annular flow channel (606); the one-to-one corresponding inner and outer annular grooves are connected through radial through holes (707), (205), (305), and (607) uniformly distributed between the two plunger holes; Four radial holes (701) evenly distributed around the circumference are provided between the first low-pressure inner annular flow channel (706) and the second high-pressure inner annular flow channel (204) of the central through hole (106) of the cylinder body, and are connected to the four large plunger holes (108) on the left end face of the cylinder body (4) to form a left flow distribution window for distributing flow to the large plunger (108) on the left end face; eight radial holes (201) evenly distributed around the circumference are provided between the second high-pressure inner annular flow channel (204) and the third low-pressure inner annular flow channel (304) of the central through hole (106) of the cylinder body. , which are connected to the eight small plunger holes (107) on the left and right side end faces of the cylinder body (4) to form an intermediate flow distribution window for distributing flow to the small plungers (107) on the left and right side end faces; four radial holes (601) evenly distributed around the circumference are opened between the third low-pressure inner annular flow channel (304) and the fourth high-pressure inner annular flow channel (606) of the central through hole (106) of the cylinder body, which are connected to the four large plunger holes (108) on the right side end face of the cylinder body (4) to form a right flow distribution window for distributing flow to the large plunger (108) on the right side end face; The distribution transmission shaft shoulder (5) is provided with four annular grooves from left to right, corresponding one to one with the annular grooves in the center hole of the cylinder body, which are respectively a first low-pressure annular flow channel (705), a second high-pressure annular flow channel (203), a third low-pressure annular flow channel (303), and a fourth high-pressure annular flow channel (605); The core portion of the shoulder of the distribution transmission shaft (5) is provided with four inner flow channels evenly distributed around the circumference, of which two are high-pressure inner flow channels (604) and the other two are low-pressure inner flow channels (704). The high-pressure and low-pressure inner flow channels (604) and (704) are staggeredly distributed in the circumferential direction, and the high-pressure inner flow channel (604) is connected to the fourth high-pressure annular flow channel (605) through and through, and the low-pressure inner flow channel (704) is connected to the first low-pressure annular flow channel (705) through and through. Four V-shaped flow distribution grooves are arranged between the first low-pressure annular flow channel (705) and the second high-pressure annular flow channel (203) and are evenly distributed along the axial circumference, so as to communicate with the left flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves (602) and the other two are low-pressure flow distribution grooves (702). The high-pressure and low-pressure flow distribution grooves (602) and (702) are staggeredly distributed in the circumferential direction, and the high-pressure flow distribution groove (602) is connected to the fourth high-pressure annular flow channel (605) through the high-pressure inner flow channels (603) and (604) of the flow distribution transmission shaft, and the low-pressure flow distribution groove (702) is connected to the first low-pressure annular flow channel (705) through the low-pressure inner flow channels (703) and (704) of the flow distribution transmission shaft; Four V-shaped distribution grooves are evenly distributed along the axial circumference between the third low-pressure annular flow channel (303) and the fourth high-pressure annular flow channel (605) for communicating with the right distribution window of the cylinder body, two of which are high-pressure distribution grooves (602) and the other two are low-pressure distribution grooves (702). The high-pressure and low-pressure distribution grooves (602) and (702) are staggered in the circumferential direction, and the high-pressure distribution groove (602) is connected to the third low-pressure annular flow channel (303) and the fourth high-pressure annular flow channel (605) through the high-pressure inner flow channels (603) and (604) of the distribution transmission shaft. The four high-pressure annular flow passages (605) are connected through the low-pressure distribution groove (702), which is connected through the low-pressure inner flow passages (703) and (704) of the distribution transmission shaft and the first low-pressure annular flow passage (705); and the high-pressure distribution groove (602) located between the first low-pressure annular flow passage (705) and the second high-pressure annular flow passage (203) and the high-pressure distribution groove (602) located between the third low-pressure annular flow passage (303) and the fourth high-pressure annular flow passage (605) are arranged in parallel in the axial direction; Four V-shaped flow distribution grooves are arranged between the second high-pressure annular flow channel (203) and the third low-pressure annular flow channel (303) and are evenly distributed along the axial circumference, so as to communicate with the middle flow distribution window of the cylinder body, two of which are high-pressure flow distribution grooves (202) and the other two are low-pressure flow distribution grooves (302). The high-pressure and low-pressure flow distribution grooves (202) and (302) are staggered in the circumferential direction, and the high-pressure flow distribution groove (202) communicates with the second high-pressure annular flow channel (203), and the low-pressure flow distribution groove (302) communicates with the second low-pressure annular flow channel (303); and the high-pressure flow distribution groove (202) between the second high-pressure annular flow channel (203) and the third low-pressure annular flow channel (303) and the high-pressure flow distribution groove (602) between the third low-pressure annular flow channel (303) and the fourth high-pressure annular flow channel (605) are arranged in parallel in the axial direction.

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