Polygonal radial plunger pump with special-shaped plunger and working method of polygonal radial plunger pump

Abstract

The invention discloses a polygonal radial plunger pump with special-shaped plungers and a working method of the polygonal radial plunger pump, and belongs to the technical field of hydraulic transmission. The transmission shaft, the polygonal stator and the eccentric rotor are arranged in the pump shell, the eccentric rotor is arranged outside the transmission shaft, the polygonal stator is arranged outside the eccentric rotor, the outer wall of the polygonal stator is attached to the special-shaped plunger, the special-shaped plunger is connected with the plunger spring, and the plunger spring is connected with the one-way valve shell. An oil inlet pipe is arranged at one end of the one-way valve shell, an oil outlet pipe is arranged at the other end of the one-way valve shell, and an oil suction valve core is arranged in the oil inlet pipe, is arranged at the oil inlet end of the oil inlet pipe and is elastically connected with the oil outlet end of the oil inlet pipe; and an oil outlet valve core is arranged in the oil outlet pipe, is arranged at the oil inlet end of the oil outlet pipe and is elastically connected with the oil outlet end of the oil outlet pipe. The problem of local abrasion caused by inclination of a traditional plunger is solved, and the service life is prolonged; the technical bottlenecks that a traditional radial plunger pump is poor in abrasion resistance, large in size and complex to maintain are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to a polygonal radial piston pump with special-shaped pistons and a working method thereof, and belongs to the technical field of hydraulic transmission. BACKGROUND

[0002] As the core device for energy conversion and transmission in hydraulic systems, radial piston pumps are widely used in industrial scenarios requiring high pressure, large flow output and precise flow control due to their high rated pressure, large power density, excellent efficiency and outstanding flow regulation characteristics. Typical applications include hydraulic machines, engineering machinery main engines and ship hydraulic systems.

[0003] The typical structural feature of conventional radial piston pumps is that multiple pistons are uniformly distributed along the rotor in the radial direction, and their reciprocating motion direction is perpendicular to the driving shaft. The working principle is as follows: the driving shaft drives the rotor to rotate, and the piston group continuously adheres to the inner wall of the eccentric stator under the combined action of centrifugal force and hydraulic pressure. Due to the eccentric design of the stator inner cavity, the pistons produce periodic reciprocating motion during the rotation of the rotor, and the single-way valve is used to realize the alternative switching of oil suction and oil discharge processes.

[0004] However, the existing radial piston pump technology has two key technical defects:

[0005] Firstly, when the piston pair is inclined, the contact stress distribution between the piston and the cylinder hole is uneven, which leads to local wear and tear, significantly shortening the service life of the piston.

[0006] Secondly, the structural characteristics of radial arrangement of pistons result in larger radial size of the pump body and higher rotational inertia of the rotating parts, which adversely affects the dynamic response characteristics of the system. SUMMARY

[0007] To solve the problems in the background art, the present application provides a polygonal radial piston pump with special-shaped pistons and a working method thereof.

[0008] To achieve the above object, the present application adopts the following technical scheme: a polygon radial plunger pump with special-shaped plungers, comprising a transmission shaft, special-shaped plungers, plunger springs, one-way valve housings, a pump housing, a polygon stator, an eccentric rotor, an oil inlet pipe, an oil outlet pipe, an oil suction valve core and an oil outlet valve core; the transmission shaft, the polygon stator and the eccentric rotor are all arranged in the pump housing, the eccentric rotor is fixedly sleeved on the outside of the transmission shaft, the polygon stator is rotatably sleeved on the outside of the eccentric rotor, the outer wall of the polygon stator is tightly combined with the inner ends of the special-shaped plungers, the outer ends of each special-shaped plunger are fixedly connected with the inner ends of the corresponding plunger springs, and the outer ends of each plunger spring are fixedly connected with the corresponding one-way valve housings; each one-way valve housing is fixedly connected with the pump housing, and the axis of each one-way valve housing is arranged in parallel with the axis of the transmission shaft; one end of each one-way valve housing is provided with the oil inlet pipe, the oil suction valve core is arranged in the oil inlet pipe, and the oil suction valve core is elastically connected between the oil inlet end of the oil inlet pipe and the oil outlet end of the oil inlet pipe through a corresponding spring; the other end of each one-way valve housing is provided with the oil outlet pipe, the oil outlet valve core is arranged in the oil outlet pipe, and the oil outlet valve core is elastically connected between the oil inlet end of the oil outlet pipe and the oil outlet end of the oil outlet pipe through a corresponding spring.

[0009] Further, the oil inlet pipe and the oil outlet pipe are connected with the one-way valve housing through threads.

[0010] Further, the outer shape curve of each special-shaped plunger conforms to the trigonometric function expression: Asinα+Bcosβ+C, wherein A and B are coefficients for adjusting the curve amplitude, C is a constant term for adjusting the overall curve offset, and α and β are angle parameters associated with the motion phase angle of the special-shaped plunger.

[0011] Further, the polygon stator is a conformal structure of the pump housing, and the eccentric part is cut off.

[0012] The working method of the polygon radial plunger pump with special-shaped plungers, the method comprising the following steps:

[0013] S1: connecting the motor shaft of an external motor with the transmission shaft;

[0014] S2: starting the motor to drive the transmission shaft to rotate around its own axis, the transmission shaft driving the eccentric rotor to rotate synchronously, and the polygon stator doing eccentric translation;

[0015] S3: The eccentric motion of the polygon stator reduces the radial extrusion force of the special-shaped plunger, the plunger spring resets to push the special-shaped plunger away from the one-way valve shell, the volume of the oil cavity in the one-way valve shell increases to form negative pressure; the negative pressure overcomes the elastic force of the spring connected to the oil suction valve core, the steel ball of the oil suction valve core is separated from the oil inlet end of the one-way valve shell, the oil tank oil enters the oil cavity through the oil inlet pipe until the volume of the oil cavity is maximum, the oil suction stage is completed, and the oil outlet valve core remains closed due to the corresponding spring pressure and external oil pressure;

[0016] S4: The eccentric rotor continues to rotate, the polygon stator changes the direction of eccentricity and extrudes the special-shaped plunger, the special-shaped plunger overcomes the elastic force of the plunger spring and approaches the one-way valve shell, the volume of the oil cavity decreases, and the pressure rises; the rising pressure overcomes the elastic force of the spring connected to the oil outlet valve core, the steel ball of the oil outlet valve core is separated from the oil inlet end of the one-way valve shell, the oil is transported to the external hydraulic system through the oil outlet pipe, and the oil discharge is completed, and the oil suction valve core remains closed due to the spring pressure and the oil pressure in the cavity;

[0017] S5: The transmission shaft continues to rotate, drives the eccentric rotor and the polygon stator to repeat the above motion, the special-shaped plunger reciprocates continuously, and the oil cavity completes the volume expansion-oil suction-volume compression-oil discharge process to realize continuous oil delivery; multiple one-way valve shells synchronize oil suction and oil discharge to output high-pressure oil to multiple external pipelines;

[0018] S6: Turn off the motor, stop the rotation of the transmission shaft, and the motion of the eccentric rotor, the polygon stator and the special-shaped plunger stops synchronously, the special-shaped plunger restores to the initial position close to the polygon stator under the action of the plunger spring, and the oil cavity returns to the initial volume; the oil suction valve core and the oil outlet valve core reset under the action of the respective spring, block the oil suction and oil discharge channels, and prevent oil from flowing back or leaking.

[0019] Compared with the prior art, the beneficial effects of the present application are:

[0020] The present application adopts a triangular function curve to optimize the special-shaped plunger, accurately controls the shapes of the head and tail, uniformly distributes the plunger contact stress, effectively solves the local wear problem caused by the inclination of the traditional plunger, significantly prolongs the service life, the polygon stator adopts a random structure and cuts off the eccentric part, shortens the diameter of the rotor circumscribed circle under the premise of ensuring radial symmetry distribution, reduces the rotational inertia of the rotating part, and improves the dynamic response characteristics of the system; the oil inlet pipe and the oil outlet pipe are connected to the one-way valve shell through threads, cooperate with the detachable oil suction valve core and the oil outlet valve core design, realize quick maintenance and replacement, and reduce the maintenance cost; multiple one-way valve shells work synchronously, the axis is parallel to the transmission shaft axis, can output high-pressure oil to multiple external pipelines, improve the output efficiency while maintaining the overall structure compactness, and comprehensively solve the technical bottlenecks of poor wear resistance, large volume and complex maintenance of the traditional radial plunger pump. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structural schematic diagram of the present application;

[0022] Figure 2 is an axial sectional view of Figure 1

[0023] Figure 3 is a radial sectional view of Figure 1

[0024] Figure 4 is a schematic diagram of the connection relationship of the one-way valve housing, the oil inlet pipe and the oil outlet pipe;

[0025] Figure 5 is a schematic diagram of the connection relationship of the one-way valve housing and the plunger pair. DETAILED DESCRIPTION

[0026] The technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0027] ​​The application discloses a polygonal radial piston pump with special-shaped pistons, which comprises a transmission shaft 1, special-shaped pistons 5, piston springs 6, one-way valve housings 7, a pump housing 8, a polygonal stator 11, an eccentric rotor 12, an oil inlet pipe 17, an oil outlet pipe 18, an oil suction valve core 19 and an oil outlet valve core 20. The transmission shaft 1, the polygonal stator 11 and the eccentric rotor 12 are arranged in the pump housing 8, a key groove is formed in the left end of the transmission shaft 1, and the key groove is used for being connected with a motor shaft. One end of the pump housing 8 is detachably fixedly connected with a pump housing cover 3 through bolts, a front end cover 2 is arranged at the connecting position of the input end of the transmission shaft 1 and the pump housing cover 3, and a rear end cover 9 is arranged at the connecting position of the output end of the transmission shaft 1 and the pump housing 8. The eccentric rotor 12 is fixedly sleeved with the transmission shaft 1 through a key 13, the polygonal stator 11 is rotatably sleeved with the eccentric rotor 12, and the polygonal stator 11 is tightly attached with the inner ends of the special-shaped pistons 5 which are arranged in the circumferential direction of the polygonal stator 11. The outer circle of the eccentric rotor 12 is in interference fit with the inner circle of a roller bearing, the outer circle of the roller bearing is attached with the inner circle of the polygonal stator 11, the outer wall of the polygonal stator 11 is tightly attached with the inner ends of the special-shaped pistons 5 which are arranged in the circumferential direction of the polygonal stator 11, the inner ends of the outer ends of the special-shaped pistons 5 are fixedly connected with the inner ends of the corresponding piston springs 6 respectively, and the outer ends of the piston springs 6 are fixedly connected with the corresponding one-way valve housings 7 respectively. The one-way valve housings 7 are fixedly connected with the pump housing 8 through the corresponding piston pairs, and the axes of the one-way valve housings 7 are arranged in parallel with the axis of the transmission shaft 1. The piston pair comprises a one-way valve connecting piece 4 and a piston guide sleeve 16. The piston guide sleeve 16 is sleeved with the outer side of the special-shaped piston 5, one end of the piston guide sleeve 16 is fixedly connected with the pump housing cover 3 through bolts, the other end of the piston guide sleeve 16 is fixedly connected with the pump housing 8 through bolts, a plurality of mounting holes are arranged in the circumferential direction of the outer wall of the pump housing 8, the one-way valve connecting pieces 4 are inserted in the mounting holes respectively, the one-way valve connecting pieces 4, the pump housing 8 and the corresponding one-way valve housings 7 are fixedly connected through bolts, the lower ends of the one-way valve connecting pieces 4 are inserted in the corresponding piston guide sleeves 16 respectively, and the one-way valve connecting pieces 4 and the piston guide sleeves 16 can be disassembled and replaced by disassembling the bolts.

[0028] Furthermore, the oil inlet pipe 17 and the oil outlet pipe 18 are connected with the one-way valve housings 7 through threads, so that the oil suction valve core 19 and the oil outlet valve core 20 can be conveniently replaced and maintained.

[0029] Further, the outer shape curve of each said special-shaped plunger 5 conforms to a trigonometric function expression: Asinα+Bcosβ+C, wherein: A and B are coefficients for adjusting the amplitude of the curve; C is a constant term for adjusting the overall offset of the curve; and α and β are angle parameters associated with the phase angle of the motion of the special-shaped plunger 5.

[0030] The design can accurately quantify the outer shape of the special-shaped plunger 5 through the trigonometric function expression, so that it adapts to the eccentric motion law of the polygon stator 11, realizes stable change of the oil cavity volume, reduces flow pulsation, ensures uniform contact between the special-shaped plunger 5 and the cooperating part, reduces mechanical wear, and facilitates parameter adjustment and optimization of the design and conversion into machining instructions.

[0031] Further, the polygon stator 11 is a conformal structure of the pump housing 8, and in order to ensure dynamic balance and ensure the center is centered, the eccentric part is cut, i.e., the polygon stator 11 is an octagonal structure.

[0032] The working method of the polygon radial plunger pump with a special-shaped plunger comprises the following steps:

[0033] S1: The motor shaft of the external motor is connected to the left end key groove of the transmission shaft 1 through a key to ensure that the motor power can be stably transmitted to the transmission shaft 1; the sealing property of the five-sided closed structure of the pump housing 8 is checked to avoid oil leakage; the steel balls in the oil suction valve core 19 and the steel balls in the oil outlet valve core 20 are confirmed to be assembled in place with the corresponding springs; there is no jamming or damage. At this time, the special-shaped plunger 5 is tightly attached to the outer circle of the polygon stator 11 under the action of the plunger spring 6, the oil cavity 21 is at the initial volume, the oil suction valve core and the oil outlet valve core are closed, and the oil flow is blocked.

[0034] S2: Start the motor to drive the transmission shaft 1 to rotate around its own axis, the transmission shaft 1 drives the eccentric rotor 12 to rotate synchronously through the key 13, the inner ring of the roller bearing in interference fit with the outer circle of the eccentric rotor 12 rotates with it, the special-shaped plunger 5 can only move vertically due to the constraint of the plunger guide sleeve 16 and the one-way valve connecting piece 4, and the polygon stator 11 is subjected to vertical pressure by the plunger spring 6, so that the polygon stator 11 moves eccentrically and does not rotate itself. The first shaft sleeve 10, the second shaft sleeve 14 and the third shaft sleeve 15 on both sides of the eccentric rotor 12 can reduce the friction between the eccentric rotor 12 and the front end cover 2 and the rear end cover 9, and ensure the stability of rotation.

[0035] S3: The polygon stator 11 eccentric motion, the special-shaped plunger 5 is reduced by radial extrusion force, the plunger spring 6 resets and pushes the special-shaped plunger 5 away from the one-way valve shell 7, the oil cavity 21 in the one-way valve shell 7 volume increases to form negative pressure; The negative pressure overcomes the elastic force of the spring connected with the oil suction valve core 19, so that the steel ball of the oil suction valve core 19 is separated from the oil inlet end of the one-way valve shell 7, and the external oil tank oil enters the oil cavity 21 through the oil inlet pipe 17, until the oil cavity 21 reaches the maximum volume, and the oil suction stage ends, and the oil outlet valve core 20 remains closed due to the corresponding spring pressure and external oil pressure;

[0036] S4: The eccentric rotor 12 continues to rotate, the polygon stator 11 changes the eccentric direction and extrudes the special-shaped plunger 5, the special-shaped plunger 5 overcomes the elastic force of the plunger spring 6 and approaches the one-way valve shell 7, the volume of the oil cavity 21 is reduced, and the pressure is increased; The increased pressure overcomes the elastic force of the spring connected with the oil outlet valve core 20, so that the steel ball of the oil outlet valve core 20 is separated from the oil inlet end of the one-way valve shell 7, and the oil is transported to the external hydraulic system through the oil outlet pipe 18, and the oil discharge is completed, and the oil suction valve core 19 remains closed due to the spring pressure and the oil pressure in the cavity;

[0037] S5: The transmission shaft 1 continues to rotate, drives the eccentric rotor 12 and the polygon stator 11 to repeat the above movement, the special-shaped plunger 5 reciprocates continuously, and the oil cavity 21 completes the volume expansion-oil suction-volume compression-oil discharge process to realize continuous oil delivery; Multiple one-way valve shells 7 synchronize oil suction and oil discharge, and output high-pressure oil to multiple external pipelines;

[0038] S6: Turn off the motor, the transmission shaft 1 stops rotating, the eccentric rotor 12, the polygon stator 11 and the special-shaped plunger 5 stop moving synchronously, the special-shaped plunger 5 restores to the initial position close to the polygon stator 11 under the action of the plunger spring 6, and the oil cavity 21 returns to the initial volume; The oil suction valve core 19 and the oil outlet valve core 20 reset under the action of the respective springs, block the oil suction and oil discharge channels, and prevent the oil from flowing back or leaking.

[0039] The structure is reliable, when working, the friction force between the polygon stator 11 and the special-shaped plunger 5 is generated, and the cooperation gap between the special-shaped plunger 5 and the plunger pair causes the special-shaped plunger 5 not to move completely in the vertical direction, the special-shaped plunger 5 optimizes the shape of the head and the tail to make the contact area between the plunger pair more reasonable, optimize the contact surface stress, and has the advantages of simple structure, high practicability and reducing the wear of the special-shaped plunger 5.

[0040] It will be obvious to a person skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments and can be implemented in other forms without departing from the spirit or essential characteristics of the application. The embodiments are considered in all respects to be illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalents of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims to the features to which the reference signs are attached.

[0041] Furthermore, it should be understood that although the description is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A polygonal radial piston pump with a special-shaped piston, characterized in that: The invention comprises a transmission shaft (1), a special-shaped plunger (5), a plunger spring (6), a one-way valve housing (7), a pump housing (8), a polygonal stator (11), an eccentric rotor (12), an oil inlet pipe (17), an oil outlet pipe (18), an oil suction valve core (19) and an oil outlet valve core (20); the transmission shaft (1), the polygonal stator (11) and the eccentric rotor (12) are all arranged in the pump housing (8); the outer side of the transmission shaft (1) is fixedly sleeved with the eccentric rotor (12); the outer side of the eccentric rotor (12) is rotatably sleeved with the polygonal stator (11); the outer wall of the polygonal stator (11) is tightly fitted with the inner ends of a plurality of special-shaped plungers (5); the outer end of each special-shaped plunger (5) is fixedly connected to the inner end of the corresponding plunger spring (6); the outer end of each plunger spring (6) is fixedly connected to the corresponding one-way valve housing ( 7) fixedly connected; each one-way valve housing (7) is fixedly connected to the pump housing (8), and the axis of each one-way valve housing (7) is arranged parallel to the axis of the transmission shaft (1); one end of each one-way valve housing (7) is installed with an oil inlet pipe (17), an oil suction valve core (19) is installed in the oil inlet pipe (17), the oil suction valve core (19) is arranged at the oil inlet end of the oil inlet pipe (17), and the oil suction valve core (19) and the oil outlet end of the oil inlet pipe (17) are elastically connected through corresponding springs; the other end of each one-way valve housing (7) is installed with an oil outlet pipe (18), an oil outlet valve core (20) is installed in the oil outlet pipe (18), the oil outlet valve core (20) is arranged at the oil inlet end of the oil outlet pipe (18), and the oil outlet valve core (20) and the oil outlet end of the oil outlet pipe (18) are elastically connected through corresponding springs.

2. A polygonal radial piston pump with a special-shaped piston according to claim 1, characterized in that: The oil inlet pipe (17) and the oil outlet pipe (18) are both connected to the one-way valve housing (7) via threads.

3. The polygonal radial piston pump with a special-shaped piston according to claim 1, characterized in that: The outer shape curve of each of the special-shaped plungers (5) conforms to the trigonometric function expression: Asinα+Bcosβ+C, wherein: A and B are coefficients for adjusting the amplitude of the curve; C is a constant term for adjusting the overall offset of the curve; α and β are angle parameters associated with the motion phase angle of the special-shaped plunger (5).

4. The polygonal radial piston pump with a special-shaped piston according to claim 1, characterized in that: The polygonal stator (11) is a conformal structure of the pump housing (8), and the eccentric portion is cut away.

5. A method for operating a polygonal radial piston pump having a special-shaped piston according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: S1: Connect the motor shaft of the external motor to the transmission shaft (1); S2: The starting motor drives the transmission shaft (1) to rotate around its own axis, and the transmission shaft (1) drives the eccentric rotor (12) to rotate synchronously, and the polygonal stator (11) performs eccentric translation; S3: The polygonal stator (11) moves eccentrically, the radial extrusion force on the special-shaped plunger (5) decreases, the plunger spring (6) resets and pushes the special-shaped plunger (5) away from the one-way valve housing (7), and the volume of the oil cavity (21) in the one-way valve housing (7) increases to form a negative pressure; the negative pressure overcomes the elastic force of the spring connected to the oil suction valve core (19), so that the steel ball of the oil suction valve core (19) is separated from the oil inlet end of the one-way valve housing (7), and the oil in the external oil tank enters the oil cavity (21) through the oil inlet pipe (17) until the volume of the oil cavity (21) is the largest, and the oil suction stage ends. During this process, the oil outlet valve core (20) remains closed due to the corresponding spring pressure and the external oil circuit pressure; S4: The eccentric rotor (12) rotates continuously, and the eccentric direction of the polygonal stator (11) changes and squeezes the special-shaped plunger (5). The special-shaped plunger (5) overcomes the elastic force of the plunger spring (6) and approaches the one-way valve housing (7). The volume of the oil cavity (21) decreases and the pressure increases. The increased pressure overcomes the elastic force of the spring connected to the oil outlet valve core (20), so that the steel ball of the oil outlet valve core (20) is separated from the oil inlet end of the one-way valve housing (7). The oil is transported to the external hydraulic system through the oil outlet pipe (18), completing the oil discharge. During this process, the oil suction valve core (19) remains closed due to the spring pressure and the oil pressure in the cavity. S5: The transmission shaft (1) rotates continuously, driving the eccentric rotor (12) and the polygonal stator (11) to repeat the above-mentioned motion. The special-shaped plunger (5) moves back and forth continuously, and the oil cavity (21) completes the volume expansion-oil absorption-volume compression-oil discharge process in a cycle, thereby realizing continuous oil delivery. The multiple one-way valve housings (7) absorb and discharge oil synchronously, and output high-pressure oil to multiple external pipelines. S6: The motor is turned off, the transmission shaft (1) stops rotating, the eccentric rotor (12), the polygonal stator (11) and the special-shaped plunger (5) stop moving synchronously, the special-shaped plunger (5) returns to its initial position close to the polygonal stator (11) under the action of the plunger spring (6), and the oil cavity (21) returns to its initial volume; the oil suction valve core (19) and the oil discharge valve core (20) are reset under the action of their respective springs, blocking the oil suction and discharge channels to prevent the reverse flow or leakage of oil.

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