CN210106086U

CN210106086U - Heavy-load force balance type two-dimensional piston monoblock pump

Info

Publication number: CN210106086U
Application number: CN201920178097.3U
Authority: CN
Inventors: 阮健; 王河缘; 吴圣; 黄煜; 金丁灿; 申屠胜男; 孟彬
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2019-01-31
Filing date: 2019-01-31
Publication date: 2020-02-21
Anticipated expiration: 2029-01-31

Abstract

The heavy-duty force-balanced two-dimensional piston monoblock pump comprises a front end cover, a coupling assembly, a pump shell and a rear end cover which are sequentially and coaxially arranged along an axis; the pump assembly comprises a pump core assembly, a left guide rail assembly and a right guide rail assembly; the pump core assembly comprises a pump core cylinder body assembly and a piston assembly; the high-pressure column of the pump core cylinder body component is connected with the second conical roller, the low-pressure column is connected with the first conical roller, and the two conical rollers are respectively matched with the two guide rail components; the piston assembly is arranged in the inner ring of the piston cylinder assembly along the axial lead direction; the piston, the left piston ring and the concentric ring surround to form a left closed cavity; the piston, the right piston ring and the concentric ring are encircled to form a right closed cavity; the two closed cavities are respectively communicated with the two distributing grooves; the left guide rail assembly comprises a left guide rail and a left balance guide rail, and the right guide rail assembly comprises a right guide rail and a right balance guide rail; the mass sum of the balance rotor composed of the left balance guide rail, the right balance guide rail and the transmission shaft is equal to the mass sum of the rotor composed of the left guide rail, the right guide rail and the piston.

Description

Heavy-load force balance type two-dimensional piston monoblock pump

Technical Field

The invention relates to a hydraulic plunger pump, belonging to a hydraulic pump and a hydraulic motor in the field of fluid transmission and control.

Background

The hydraulic pump is used as an energy power element in a hydraulic system and plays a decisive role in system performance and working efficiency. With the rapid development of industrial technology in China, hydraulic pumps have been widely applied in important fields such as aerospace, marine ships and the like. The traditional plunger pump is difficult to achieve the aims of high efficiency, high pressure, light weight and small vibration due to the limitations of friction pairs, size and the like.

The traditional plunger pump has a complex internal structure, more parts moving relatively, higher requirements on materials and processing precision, sensitivity to oil pollution, higher processing and maintenance costs and requirements and high price; the cylinder body rotates along with the transmission shaft, and the rotational inertia is large, so that the response speed of starting, stopping and speed regulation is low, and the control of the output flow of the pump by the speed regulation is not facilitated; the pump structure has more friction pairs, and parts of the pump are seriously abraded and heated under high-speed rotation, so that the service life and the durability of the pump are directly influenced.

Because of various defects of the conventional plunger pump, patent document CN205895515U proposes a hydraulic pump with a novel structure, which can rotate by using the motion principle of two degrees of freedom of a piston and can move axially to realize the oil sucking and discharging functions, and is named as a two-dimensional 2D piston pump because it has two-dimensional motion during operation. The two-degree-of-freedom motion principle is applied to the design of a piston of the pump, and a novel flow distribution mode is formed. The device has the advantages of novel and compact structure, small volume, light weight, simple transmission, high discharge capacity and high volumetric efficiency. However, two-dimensional (2D) piston pumps have disadvantages in terms of high speed, operational stability, and heavy load.

Disclosure of Invention

The invention provides a heavy-load force balance type two-dimensional piston monoblock pump, which overcomes the defects in the prior art.

The invention discloses a heavy-load force balance type two-dimensional piston monoblock pump which comprises a front end cover, a coupling assembly, a pump shell and a rear end cover which are sequentially and coaxially arranged along an axis. An oil outlet is formed in the upper portion of the pump shell, an annular groove is formed in the pump shell, and the oil outlet is communicated with the annular groove; the front end cover is fixed on the left end face of the pump shell, the rear end cover is fixed on the right end face of the pump shell, and the center of the end face of the rear end cover is provided with an oil suction port.

The pump assembly comprises a pump core assembly, a left guide rail assembly and a right guide rail assembly; the pump core assembly comprises a pump core cylinder assembly and a piston assembly.

The pump core cylinder body assembly comprises a pair of high-pressure columns and a pair of low-pressure columns, the high-pressure columns are arranged along a first diameter of the pump core cylinder body, the low-pressure columns are arranged along a second diameter of the pump core cylinder body, and the first diameter and the second diameter are perpendicular to each other and are positioned at different positions of an axial line; a through hole is formed in the radial direction of the high-pressure column, and a U-shaped groove is formed in the position, close to the center of the cylinder body, of the low-pressure column; the high-pressure column is communicated with the annular groove; a pair of oil outlet holes and a pair of oil inlet holes are formed in the inner ring of the cylinder body, and the oil outlet holes and the oil inlet holes are rectangular holes which are circumferentially and alternately distributed; the cylinder body outer ring is provided with a pair of left mounting holes for mounting a high-pressure column and a pair of right mounting holes for mounting a low-pressure column; the oil outlet hole is communicated with the left mounting hole, and the oil inlet hole is communicated with the right mounting hole; the oil outlet is communicated with the through hole of the high-pressure column, and the oil inlet is communicated with the U-shaped groove of the low-pressure column; the pair of high-pressure columns are inserted into the left mounting hole and are respectively connected with the second cone roller through the bearings, and the second cone roller moves in a matched manner with the left guide rail assembly; a pair of low-pressure columns are inserted into the right mounting hole and are respectively connected with a first conical roller through a bearing, and the first conical rollers move in a matched manner with the right guide rail assembly.

The piston assembly is arranged in the inner ring of the piston cylinder body assembly along the axial lead direction. The piston assembly comprises a piston, a concentric ring, a transmission shaft, a left piston ring and a right piston ring. The concentric ring inner ring is provided with a pair of high-pressure holes and a pair of low-pressure holes, the high-pressure holes and the low-pressure holes are rectangular holes which are circumferentially and alternately distributed, and the width of the high-pressure holes and the width of the low-pressure holes are consistent with that of the oil inlet holes and the oil outlet holes on the inner ring of the pump core cylinder body; the low-pressure hole is communicated with the oil inlet hole, and the high-pressure hole is communicated with the oil outlet hole; the outer ring of the concentric ring is in interference fit with the inner ring of the pump core cylinder body. A pair of first distributing grooves and a pair of second distributing grooves are circumferentially and alternately distributed on the wall surface of the piston, the first distributing grooves and the second distributing grooves are U-shaped grooves with opposite axial directions, and the width of the first distributing grooves is consistent with that of the high-pressure holes and the low-pressure holes. The outer ring of the piston and the inner ring of the concentric ring are in clearance fit and can move circumferentially and axially relative to the concentric ring. The piston is axially provided with a through hole, and two ends of the piston are provided with rectangular keys for mounting the left guide rail and the right guide rail. The transmission shaft is in clearance fit with the through hole of the piston and can axially move relative to the piston; the two ends of the transmission shaft are provided with rectangular keys for mounting the left and right balance guide rails.

The piston, the left piston ring and the concentric ring surround to form a left closed cavity. One side close to the piston cylinder body is taken as the inner side, and the inner side of the left piston ring is in a circular structure and is sleeved on the step on the left side of the piston; the outer ring of the annular structure is flush with the outermost circle of the piston and is in clearance fit with the inner ring of the concentric ring, and the inner ring is in clearance fit with the step on the left side of the piston. The piston, the right piston ring and the concentric ring are surrounded to form a right closed cavity, and the sealing mode of each component is the same as that of the left closed cavity. The right closed cavity is always communicated with the first distribution groove, and the left closed cavity is always communicated with the second distribution groove.

The left guide rail assembly comprises a left guide rail and a left balance guide rail, and the right guide rail assembly comprises a right guide rail and a right balance guide rail; the left guide rail and the right guide rail are arranged at two ends of the piston, the left guide rail, the right guide rail and other equal deceleration curved surfaces are respectively matched with the second conical roller and the first conical roller to move, and the highest point and the lowest point on the equal deceleration curved surfaces of the left guide rail and the right guide rail correspond to each other; the left balance guide rail and the right balance guide rail are arranged at two ends of the transmission shaft, the left balance guide rail, the right balance guide rail and other equal deceleration curved surfaces move in a matched mode with the second cone roller and the first cone roller, and the highest points and the lowest points on the equal deceleration curved surfaces of the left balance guide rail and the right balance guide rail correspond to the lowest points. The left balance guide rail and the right balance guide rail are respectively sleeved outside the left guide rail and the right guide rail, have the same shape with the left guide rail, the right guide rail and other equal deceleration curved surfaces and are circumferentially staggered by 90-degree phase angles; the mass sum of a balance rotor consisting of the left balance guide rail, the right balance guide rail and the transmission shaft is equal to the mass sum of a rotor consisting of the left guide rail, the right guide rail and the piston; when the left track and the right track drive the piston to do equal deceleration motion, the left balance track and the right balance track drive the transmission shaft to do equal deceleration motion in the circumferential direction in the same direction and in the axial direction in the opposite direction, and inertia force caused by axial motion of the rotor is offset.

The left end of the coupling assembly is axially fixed with the front end cover through a bearing and a sealing piece, the right end of the coupling assembly is connected with a left guide rail assembly in the pump core assembly through a shifting fork structure, and the free relative axial movement is realized while the coupling assembly and the left guide rail assembly of the pump core assembly keep synchronous rotation.

The axial direction refers to the direction of the central axis of the piston; the radial direction refers to the diameter direction of the cross section of the piston; the circumferential direction refers to a direction of rotation about the central axis of the piston.

Oil enters the right cavity of the pump shell from the oil suction port of the rear end cover, the left end of the right cavity is sealed by the pump core cylinder body assembly and the pump shell through a sealing ring, and the right end of the right cavity is sealed by the rear end cover and the pump shell through a sealing ring. Oil enters the low-pressure holes of the concentric rings through the U-shaped groove of the low-pressure column.

When the second conical roller contacts with the lowest point of the curved surface of the left guide rail and the highest point of the curved surface of the left balance guide rail, the first conical roller contacts with the highest point of the curved surface of the right guide rail and the lowest point of the curved surface of the right balance guide rail, and the two pairs of distributing grooves of the piston and the high-pressure hole and the low-pressure hole on the cylinder body are in a critical state of communication and non-communication. When the lowest point of the curved surface of the second guide rail moves to the highest point, the left guide rail drives the piston to move in the same direction and move leftwards, and the piston drives the highest point of the right guide rail to move to the lowest point; when the highest point of the curved surface of the left balance guide rail moves to the lowest point, the left balance guide rail drives the transmission shaft and the left piston ring to rotate in the same direction and move rightwards, the transmission shaft drives the lowest point of the right balance guide rail to move towards the highest point, and the right balance guide rail drives the right piston ring to rotate in the same direction and move rightwards. At the moment, the first distributing groove is communicated with the low-pressure hole, and the right closed containing cavity gradually enlarges and absorbs oil due to the leftward movement of the piston and the rightward movement of the right piston ring.

When the lowest point of the curved surface of the right guide rail moves to the highest point, the right guide rail drives the piston to move in the same direction and move rightwards, and the piston drives the highest point of the left guide rail to move to the lowest point; when the highest point of the curved surface of the right balance guide rail moves to the lowest point, the right balance guide rail drives the transmission shaft and the right piston ring to rotate in the same direction and move leftwards, the transmission shaft drives the lowest point of the left balance guide rail to move towards the highest point, and the left balance guide rail drives the left piston ring to rotate in the same direction and move leftwards. At the moment, the first distributing groove is communicated with the high-pressure hole, and the left closed cavity is gradually reduced to discharge oil due to the rightward movement of the piston and the leftward movement of the right piston ring. High-pressure oil flows into the high-pressure column through hole through the oil outlet hole, and flows out from the oil outlet after converging through the annular groove of the pump shell.

At the moment, the closed cavity finishes one-time oil suction and discharge, the guide rail and the balance guide rail continue to rotate, and the periodic motion is repeated to continuously suck and discharge oil.

Furthermore, the front end cover is fixedly connected to the left end face of the pump shell through a bolt, and the rear end cover is fixedly connected to the right end face of the pump shell through a bolt.

Further, the pump core cylinder body assembly is fixed inside the pump shell through threaded connection.

Further, a left concentric ring is arranged between the left piston ring and the piston, and a right concentric ring is arranged between the right piston ring and the piston; the left side of the left concentric ring is provided with a left check ring in an interference fit mode, and the right side of the right concentric ring is provided with a right check ring in an interference fit mode.

Furthermore, a pair of radial mounting holes are respectively formed in the U-shaped structures on the outer sides of the left piston ring and the right piston ring, and a pair of radial mounting holes are respectively formed in the left balance guide rail and the right balance guide rail in the guide rail assembly. The left piston ring is fixed on the left balance rail by penetrating two pins into a U-shaped structure on the outer side of the left piston ring and a radial mounting hole on the left balance rail; the fixing mode of the right piston ring and the right balance guide rail is the same as that of the left piston ring and the left balance guide rail.

The invention has the following beneficial effects:

1. the change of the volume of the cavity is completed by the cooperation of the piston and the piston ring, and is doubled compared with the change of the traditional single piston. Under the condition of the same displacement and stroke, the cross-sectional area is reduced, so that the stress on the guide rail and the conical roller is reduced, and high load is easy to realize.

2. The high-pressure column and the low-pressure column of the fixed cone roller have larger diameters, can bear increased load, and are easy to realize high load;

3. because the high-pressure column and the low-pressure column with larger diameters are selected as the support columns of the cone roller, the bearing with larger diameter can be selected, and the service life of the cone roller is prolonged.

4. Compared with the traditional plunger pump, the balance rotor matched with the left piston ring, the right piston ring, the piston and the balance guide rail is used for balancing the inertia force generated by the axial reciprocating motion of the piston and the guide rail, and the vibration during the mechanical motion is reduced. The output rotating speed of the motor is more stable, and the flow pulsation is reduced.

5. The guide rail, the balance guide rail and the conical roller are lubricated in oil, so that friction is reduced, and the service life is prolonged.

Drawings

FIG. 1 is an assembly schematic of the present invention;

FIG. 2 is a schematic view of a pump casing configuration of the present invention;

FIG. 3 is a schematic view of the rear end cap of the present invention;

FIG. 4 is a schematic view of a pump assembly of the present invention;

FIG. 5 is a schematic view of a pump cartridge assembly of the present invention;

FIG. 6 is an exploded view of the pump cartridge cylinder assembly of the present invention;

fig. 7a, 7b and 7c are schematic views of the piston assembly of the present invention, and fig. 7c is a sectional view of the piston corresponding to the section line a-a on 7 b.

FIGS. 8 a-8 d are cross-sectional views of the piston assembly and pump core cylinder assembly of the present invention; FIG. 8a is a schematic view of a left closed volume of the present invention; FIG. 8b is a schematic view of a right enclosed volume of the present invention; FIG. 8c is a top view of the piston assembly and pump core cylinder assembly of the present invention; FIG. 8d is a front view of the piston assembly and pump core cylinder assembly of the present invention;

FIG. 9 is an assembly view of the left and right guide rail assemblies of the present invention;

fig. 10a to 10c are three views of the left balance rail of the present invention, fig. 10a is a front view of the left balance rail of the present invention, fig. 10b is a left view of the left balance rail of the present invention, and fig. 10c is a top view of the left balance rail of the present invention;

FIGS. 11 a-11 b are schematic views of a left guide rail of the present invention, FIG. 11a is a front view of the left guide rail of the present invention, and FIG. 11b is a left view of the left guide rail of the present invention;

FIG. 12 is a schematic view of a left track assembly mounting groove of the present invention;

fig. 13a to 13c are three views of the right balance rail of the present invention, fig. 13a is a front view of the right balance rail of the present invention, fig. 13b is a left view of the right balance rail of the present invention, and fig. 13c is a top view of the right balance rail of the present invention;

FIGS. 14 a-14 b are schematic views of a right guide rail of the present invention, FIG. 14a is a front view of the right guide rail of the present invention, and FIG. 14b is a left view of the right guide rail of the present invention;

FIG. 15 is a schematic view of a right rail assembly of the present invention;

fig. 16a is a schematic view of a coupling assembly of the present invention, and fig. 16b is an exploded view of the coupling assembly of the present invention.

FIG. 17 is a schematic view of the present invention;

fig. 18 a-18 d are cross-sectional views of the flow channel of the present invention rotated through 0-180 deg., corresponding to the sectional line a-a in fig. 17. Where fig. 18a is a cross-sectional view of a flow channel of the present invention turned to 0 ° or 180 °, fig. 18b is a cross-sectional view of a flow channel of the present invention turned to 45 °, fig. 18c is a cross-sectional view of a flow channel of the present invention turned to 90 °, and fig. 18d is a cross-sectional view of a flow channel of the present invention turned to 135 °.

Detailed description of the preferred embodiments

The invention is further described below with reference to the accompanying drawings.

The heavy-load force balance type two-dimensional piston monoblock pump comprises a front end cover 1, a coupler assembly 2, a pump assembly 3, a pump shell 4 and a rear end cover 5 which are sequentially and coaxially arranged along an axis. The front end cover 1 is fixedly connected to the left end face of the pump shell 4 through bolts, the rear end cover 5 is fixedly connected to the right end face of the pump shell 4 through bolts, and an oil suction opening 5A is formed in the center of the end face of the rear end cover 5. The left end of the coupling assembly 2 is axially fixed with the front end cover 1 through a bearing and a sealing piece, and the right end of the coupling assembly 2 is restrained by the pump assembly 3, so that the coupling assembly 2 is axially fixed and can rotate in the circumferential direction in the pump shell 4.

The pump housing 4 is internally provided with an annular groove 4B. The left end of the right side cavity 4C of the pump shell 4 is sealed by the pump assembly 3 and the pump shell 4 through a sealing piece, and the right end of the right side cavity 4C of the pump shell 4 is sealed by the pump shell 4 and the rear end cover 5 through a sealing piece. An oil outlet 4A communicated with the annular groove 4B is formed in the upper portion of the pump shell.

The pump assembly 3 is fixed inside the pump housing 4 by means of a thread. The pump assembly 3 comprises a left guide rail assembly 6, a pump core assembly 7 and a right guide rail assembly 8. The left guide rail assembly 6 and the right guide rail assembly 8 are symmetrically arranged at two ends of the pump core assembly 7.

The pump core assembly 7 comprises a pump core cylinder assembly 71 and a piston assembly 72.

The pump core cylinder assembly 71 includes a pair of low pressure columns 712 disposed along a first diameter of the pump core cylinder 714 and a pair of high pressure columns 711 disposed along a second diameter of the pump core cylinder 714, the first and second diameters being perpendicular to each other and located at different positions on the shaft axis. One end of the low-pressure column 712 close to the axial lead is provided with a U-shaped groove 71A, and the high-pressure column 711 is provided with a through inner hole 71F. The low pressure column 712 is coupled to a first tapered roller 713 via a bearing, and the high pressure column 711 is coupled to a second tapered roller 715 via a bearing. The pump core cylinder 714 comprises an outer ring 71D and an inner ring 71E which are concentrically arranged, the inner ring 71E is provided with a pair of oil inlet holes 71G and a pair of oil outlet holes 71H, the oil outlet holes 71H and the oil inlet holes 71G are rectangular holes which are circumferentially and alternately distributed, the oil inlet holes 71G are communicated with the U-shaped groove 72A of the low-pressure column 712, and the oil outlet holes 71H are communicated with the inner hole 71F of the high-pressure column 711; the outer ring is provided with a mounting hole 71B of the high-pressure column 711 and a mounting hole 71C of the low-pressure column 712, wherein the mounting hole 71B of the high-pressure column 711 communicates with the annular groove 4B; the mounting hole 71C of the low-pressure column 712 communicates with the oil inlet hole 71G on the inner ring, and the mounting hole 71B of the high-pressure column communicates with the oil outlet hole 71H on the inner ring. The left track assembly 6 is in contact with only the second cone roller 715 and the right track assembly 8 is in contact with only the first cone roller 713.

The piston assembly 72 is arranged in the inner ring 71E along the axial lead direction, and comprises a transmission shaft 721, a left piston ring 722, a right piston ring 729, a left retainer 723, a right retainer 727, a left concentric ring 724, a right concentric ring 726, a concentric ring 728 and a piston 725. The concentric ring 728 is provided with 2 pairs of rectangular holes which are circumferentially and alternately distributed, namely a low-pressure hole 72C and a high-pressure hole 72D, and the excircle of the concentric ring 728 is in interference fit with the inner ring 71E of the pump core cylinder body 714. Rectangular splines are arranged at two ends of the piston 725, a pair of first distributing grooves a and b and a pair of second distributing grooves C and D are alternately and uniformly distributed on the wall surface of the piston 725 in the circumferential direction, wherein the first distributing grooves a and b and the second distributing grooves C and D are all U-shaped distributing grooves with opposite axial openings, and the widths of the first distributing grooves a and b and the second distributing grooves C and D are consistent with the widths of the high-pressure holes 72D or the low-pressure holes 72C of the concentric rings 728. The left concentric ring 724 and the right concentric ring 726 are respectively sleeved on the first-stage steps 72B on the two sides of the piston 725 in a clearance fit manner. The left retainer 723 and the right retainer 727 are respectively sleeved on the two-stage steps 72A on the two sides of the piston 725 in an interference fit manner to respectively fix the left concentric ring 724 and the right concentric ring 726. The first step 72B is located between the piston 725 and the second step 72A. The outer side of the left piston ring 722 and the outer side of the right piston ring 729 are both of U-shaped structures, the inner side of the left piston ring 722 is of an annular structure, the U-shaped structure on the outer side of the left piston ring 722 is fixedly arranged on the left guide rail assembly 6 through a pin shaft, and the U-shaped structure on the outer side of the right piston ring 729 is fixedly arranged on the right guide rail assembly 8 through a pin shaft. The inner circle of the ring structure on the inner side of the left piston ring 722 is in clearance fit with the outer circle of the left concentric ring 724, the inner circle of the ring structure on the inner side of the right piston ring 729 is in clearance fit with the outer circle of the right concentric ring 726, and the left piston ring 722 and the right piston ring 729 are symmetrically arranged on two sides of the piston 725. The outer circle of the transmission shaft 721 is in clearance fit with the inner circle of the piston 725, and the transmission shaft 721 and the piston 725 axially move relatively. The transmission shaft 721 is respectively connected with the left balance guide rail 61 on the left guide rail assembly 6 and the right balance guide rail 82 on the right guide rail assembly 8 through rectangular keys at two ends, and the piston 725 is respectively connected with the left guide rail 62 on the left guide rail assembly 6 and the right guide rail 81 on the right guide rail assembly 8 through rectangular keys at two ends. The transmission shaft 721 and the piston 725 make opposite axial reciprocating motions while making circumferential motions in the same direction under the constraint of the left guide rail assembly 6 and the right guide rail assembly 8.

The right piston ring 729, the right concentric ring 726, the piston 725 and the concentric ring 728 of the pump core assembly enclose a right closed cavity B. A gap is sealed between the inner circle of the concentric ring 728 and the inner circle of the right piston ring 729. A gap seal is provided between the inner circle of the concentric ring 728 and the outer circle of the piston 725. And a gap is sealed between the inner circle of the inner side of the right piston ring 729 and the outer circle of the right concentric ring 726. The left piston ring 722, the left concentric ring 724, the piston 725 and the concentric ring 728 in the pump core body enclose a left closed cavity A, and the sealing mode of all the parts is consistent with that of a right closed cavity B. The right closed chamber B is always in communication with the first distribution groove a, B of the piston 725, and the left closed chamber a is always in communication with the second distribution groove c, d of the piston 725. The low-pressure hole 72C of the concentric ring 728 is communicated with the oil inlet hole 71G of the pump core cylinder 715, and the high-pressure hole 72D of the concentric ring 728 is communicated with the oil outlet hole 71H of the pump core cylinder 715. The piston 725 rotates circumferentially and reciprocates axially in a concentric ring 728 under the constraint of the left guide rail assembly 6 and the right guide rail assembly 8, so that the piston 725 and the pump core cylinder 714 distribute, feed and discharge oil.

According to the heavy-load force balance type two-dimensional piston monoblock pump, oil enters the right-side cavity 4C from the oil inlet 5A of the rear end cover 5. The oil in the right chamber 4C flows through the U-shaped groove 71A of the low pressure column 712 to the oil inlet 71G of the pump core cylinder 714. The piston 725 simultaneously rotates circumferentially and reciprocates axially, and oil enters the right seal chamber B as the first distribution grooves a, B communicate with the low pressure ports 72C of the concentric ring 728. When the right sealing cavity B is compressed, the oil inside the right sealing cavity B is pressurized into high-pressure oil; the first distributing grooves a, b are now in communication with the high pressure holes 72D in the concentric ring 728, and high pressure oil enters the inner bore 71F of the high pressure column 711. The high-pressure oil in the inner hole 71F of the high-pressure column 711 of the pump assembly 3 passes through the annular groove 4B of the pump housing 4 and then flows out from the oil outlet 4A above the pump housing 4. The left closed cavity A sucks and discharges oil in the same way as the right closed cavity B, but the phase of the oil pumping curve is opposite.

The left guide rail assembly 6 comprises a left guide rail 62 and a left balance guide rail 61, and the right guide rail assembly 8 comprises a right guide rail 81 and a right balance guide rail 82. The installation directions of the left guide rail assembly 6 and the right guide rail assembly 8 are axially opposite. With the side close to the pump cylinder block assembly 71 as the inner side, the track surfaces of the right rail 81 and the right balance rail 82 and the left rail 62 and the left balance rail 61 are both disposed toward the inner side, the first cone roller 713 rolls on the right rail 81 and the right balance rail 82, and the second cone roller 715 rolls on the left rail 62 and the left balance rail 61.

The left guide rail 62 is circular, the inner side of the left guide rail is a working surface conforming to the equal acceleration and equal deceleration curves, the outer side of the left guide rail is U-shaped, a rectangular key groove is formed in the center of the left guide rail 62, and the working curved surface of the left guide rail 62 is matched with the corresponding second cone roller 715 to rotate.

The left balance guide rail 61 is in a circular ring shape, the inner side of the left balance guide rail 61 is a working surface which conforms to the equal acceleration and equal deceleration curves, the working surface is matched with the corresponding second cone roller 715 to rotate, the outer side of the left balance guide rail 61 is provided with 2 pairs of first slots 6C and second slots 6B which are alternately distributed, wherein the first slot 6C is used for installing the left guide rail 62, the second slot 6B and a pair of holes 6A which are arranged on two sides are used for connecting a left piston ring 722, and the center of the end surface of the left balance guide rail 61 is provided with a rectangular key groove. After the left guide rail 62 is installed in the first slot 6C of the left balance guide rail 61, 4 installation grooves 6D are formed on the outer side of the left balance guide rail 61, and the installation grooves 6D of the left guide rail assembly 6 of the pump assembly 3 are used for installing the coupler assembly 2.

The right balance guide rail 82 is in a circular ring shape, the inner side of the right balance guide rail 82 is a working surface which conforms to the equal acceleration and equal deceleration curves, the working surface is matched with the corresponding first conical roller 713 to rotate, the outer side of the right balance guide rail 82 is provided with 2 pairs of first slots 8C and second slots 8B which are alternately distributed, wherein the first slot 8C is used for installing the right guide rail 81, the second slot 8B and a pair of holes 8A which are arranged on two sides are used for connecting a right piston ring 729, and the center of the end surface of the right balance guide rail 82 is provided with a rectangular key groove. The right guide rail 81 is installed in the first slot 8C of the right balance guide rail 82, and the rear outer side of the right balance guide rail 82 is flush with the outer side of the right balance guide rail 82, so that a mounting groove is not formed.

The left guide rail 62 and the right guide rail 81 are fixed at both ends of the piston 725 through rectangular keys, respectively. The left balance guide rail 61 is fixedly connected with the left piston ring 722 through a pin, the right balance guide rail 82 is fixedly connected with the right piston ring 729 through a pin, and meanwhile, the left balance guide rail 61 and the right balance guide rail 82 are respectively fixed at two ends of the transmission shaft 721 through rectangular keys. The phases of the equal-adding deceleration curved surfaces of the left balance guide rail 61 and the right balance guide rail 82 are consistent, the phases of the equal-adding deceleration curved surfaces of the left guide rail 62 and the right guide rail 81 are consistent, and the phases of the equal-adding deceleration curved surfaces of the left balance guide rail 61 and the equal-adding deceleration curved surfaces of the left guide rail 62 are circumferentially staggered by 90 degrees.

The left guide rail 62 moves circumferentially, and under the constraint of the first conical roller 713 and the second conical roller 715, the left guide rail 62 and the right guide rail 81 drive the piston 725 to axially reciprocate while rotating circumferentially in the concentric ring 728; meanwhile, the left balance guide rail 61 performs circumferential rotation, and under the constraint of the first cone roller 713 and the second cone roller 715, the left balance guide rail 61, the right balance guide rail 82, the transmission shaft 721, the left piston ring 722 and the right piston ring 729 perform circumferential synchronous rotation and axial reciprocating motion. The axial motion of the balance rotor composed of the left balance guide rail 61, the right balance guide rail 82, the transmission shaft 721, the left piston ring 722 and the right piston ring 729 is opposite to the axial motion of the rotor composed of the left guide rail 62, the right guide rail 81 and the piston 725. That is, in the axial direction, the left guide rail 62 and the right guide rail 81 move with acceleration such as curved surfaces, and the left balance guide rail 61 and the right balance guide rail 82 move with acceleration such as curved surfaces, and the axial movement directions of the two are opposite; the left guide rail 62 and the right guide rail 81 perform equal deceleration movement on curved surfaces, the left balance guide rail 61 and the right balance guide rail 82 perform equal deceleration movement on curved surfaces, and the axial movement directions of the left guide rail and the right balance guide rail are opposite; the mass sum of the balance rotor composed of the left balance guide rail 61, the right balance guide rail 82, the transmission shaft 721, the left piston ring 722 and the right piston ring 729 is equal to the mass sum of the rotor composed of the left guide rail 62, the right guide rail 81 and the piston 725, the two rotors axially move in opposite directions regularly, and the inertia force generated by the axial reciprocating motion of the two rotors is counteracted.

The coupling assembly 2 comprises a coupling 21 and 4 flat rollers 22. The side surface of the coupler 21 is circumferentially provided with 4 through holes 2C, the left end surface of the coupler 21 is provided with 2 pairs of through

grooves

2A and 2B which are distributed alternately, and the right end surface is hollowed out. The coupler 21 and the left guide rail assembly 6 of the pump assembly 3 are connected with each other by adopting a shifting fork structure as follows: put into the round pin axle in 4 through-holes 2C of shaft coupling 21 in order to fix 4 flat gyro wheels 22, 4 flat gyro wheels 22 are put into the mounting groove 6D of the left rail set 6 of pump package spare 3. The through

grooves

2A and 2B of the coupler provide an avoiding space for the left guide rail assembly 6 of the pump assembly 3. So that the left guide rail assembly 6 of the pump assembly 3 is free to move axially relative to one another while maintaining synchronous rotation.

Principle of operation

Oil enters the right-hand chamber 4C from the oil intake 5A. The oil in the right chamber 4C flows through the U-shaped groove 71A of the low pressure column 712 to the oil inlet 71G of the pump core cylinder 714. The piston 725 is rotated in a circumferential direction so that the first distributing grooves a, B communicate with the low pressure holes 72C of the concentric ring 728 and oil enters the right seal chamber B. When the right seal chamber B is compressed, the oil inside is pressurized to become high pressure oil, and the first distributing grooves a, B communicate with the high pressure holes 72D on the concentric ring 728, so that the high pressure oil enters the inner hole 71F of the high pressure column 711. The high-pressure oil in the inner hole 71F of the high-pressure column 711 of the pump core assembly 7 is converged in the annular groove 4B of the pump shell 4, and then flows out from the oil outlet 4A above the pump shell 4. The oil absorption and oil discharge of the left closed cavity A are consistent with those of the right closed cavity B.

The motion law is shown in fig. 18a to 18 d.

Initially at 0 degrees of circumferential rotation, the left piston ring 722, the right piston ring 729 and the piston 725 in the pump assembly 3 move to a neutral position of axial travel. At the moment, the volumes of the hydraulic oil contained in the right closed cavity B and the left closed cavity A are equal; the first distribution grooves a, b of the piston 725 communicate with the low pressure holes 72C of the concentric ring 728 and the second distribution grooves C, D of the piston 725 communicate with the high pressure holes 72D of the concentric ring 728, and the openings are in a fully open state, i.e., the communication area is maximized. The left guide rail assembly 6 in the pump assembly 3 is rotated clockwise by the coupling assembly 2. The right piston ring 729 moves rightward along the axial stroke under the action of the right balance guide rail 82, the piston 725 moves leftward along the axial stroke under the action of the left guide rail 62 and the right guide rail 81, so that the right closed cavity B becomes larger gradually, hydraulic oil flows in through the U-shaped groove 71A and enters the right closed cavity B from the low-pressure hole 72C of the concentric ring 728 through the first distributing grooves a and B. And meanwhile, under the action of the left balance guide rail 61, the left piston ring 722 moves rightwards along the axial stroke, the piston 725 moves leftwards to enable the left closed cavity A to become smaller gradually, and high-pressure oil flows out from the left closed cavity A through the second flow distribution grooves c and D, the high-pressure holes 72D of the concentric rings 728, the inner hole 71F, the annular groove 4B and the oil outlet 4A. The piston 725 is axially reciprocated and rotated in the circumferential direction by the left and right guide rails 62 and 81, and the axial displacement thereof follows a deceleration curve such as an equal acceleration. As the piston 725 moves to the left along the axial stroke, it simultaneously rotates in the circumferential direction. The communication area between the first distributing grooves a, b and the low-pressure holes 72C of the concentric ring 728 and the communication area between the second distributing grooves C, D and the high-pressure holes 72D of the concentric ring 728 become gradually smaller. The piston 725 of the pump assembly 3 continues to move to the left along the axial stroke under the action of the left and right guide rails 62 and 81, and the left and right piston rings 722 and 729 continue to move to the right along the axial stroke under the action of the left and right balance rails 61 and 82, respectively.

After 45 degrees of rotation, the piston 725 of the pump assembly 3 moves to the leftmost end of the axial stroke, the left piston ring 722 and the right piston ring 729 move to the rightmost end of the axial stroke, at this time, the volume of the right closed cavity B reaches the maximum, the volume of the left closed cavity a reaches the minimum, the communication area between the first distributing grooves a and B of the piston 725 and the low-pressure hole 72C of the concentric ring 728 and the communication area between the second distributing grooves C and D and the high-pressure hole 72D of the concentric ring 728 are completely closed, and oil contained in the left closed cavity a and the right closed cavity B is not communicated with oil contained in the cavity 4C and the inner hole 71F. The piston 725 of the pump assembly 3 starts moving to the right along an axial stroke under the action of the left and right guide rails 62 and 81, and the left and right piston rings 722 and 729 starts moving to the left along an axial stroke under the action of the left and right balance rails 61 and 82, respectively.

After rotating 90 degrees, the left piston ring 722, the right piston ring 729 and the piston 725 of the pump assembly 3 move to the middle position of the axial stroke, the left closed cavity a and the right closed cavity B are equal in volume, and the first flow distribution grooves a and B of the piston 725 and the high-pressure hole 72D and the second flow distribution grooves C and D of the concentric ring 728 and the low-pressure hole 72C of the concentric ring 728 are in a state of being completely opened, namely, the communication area is maximum. Hydraulic oil flows in through the U-shaped groove 71A from the low pressure port 72C of the concentric ring 728 through the second distribution grooves C, d into the left closed chamber a. High-pressure oil flows out from the right closed cavity B through the first distributing grooves a and B, the high-pressure holes 72D of the concentric rings 728, the inner hole 71F, the annular groove 4B and the oil outlet 4A. The piston 725 in the pump core assembly 3 continues to move to the right along the axial stroke by the left and right guide rails 62 and 81, and the left and right piston rings 722 and 729 continue to move to the left along the axial stroke by the left and right balance rails 61 and 82, respectively.

After 135 degrees of rotation, the piston 725 in the pump component 3 moves to the rightmost end of the axial stroke, the left piston ring 722 and the right piston ring 729 move to the leftmost end of the axial stroke, the volume of the left closed cavity A reaches the maximum, the volume of the cavity B reaches the minimum, the communication area between the first distributing grooves a and B of the piston 725 and the high-pressure hole 72D of the concentric ring 728 and the communication area between the second distributing grooves C and D and the low-pressure hole 72C of the concentric ring 728 are completely closed, and oil contained in the left closed cavity A and the right closed cavity B is not communicated with oil contained in the cavity 4C and the inner hole 71F. The piston 725 in the pump core assembly 3 starts moving to the left along an axial stroke by the left and right guide rails 62 and 81, and the left and right piston rings 722 and 729 starts moving to the right along an axial stroke by the left and right balance rails 61 and 82, respectively.

After the pump rotates 180 degrees, the position and the movement trend of the moving part in the heavy-duty force balance type two-dimensional piston single pump are the same as the time of fig. 18a, and the periodic movement is repeated from the next time.

When the piston 725 rotates 180 degrees, the two sealing cavities A and B respectively suck and discharge oil for 1 time; the two seal chambers a and B each suck and discharge oil 2 times when the piston 725 completes its reciprocating motion twice per 360 degrees of rotation.

The embodiments described in this specification are merely illustrative of implementations of the inventive concept and the scope of the present invention should not be considered limited to the specific forms set forth in the embodiments but rather by the equivalents thereof as may occur to those skilled in the art upon consideration of the present inventive concept.

Claims

1. Heavy-duty type force balance formula two-dimensional piston monoblock pump, its characterized in that: the pump comprises a front end cover, a coupling assembly, a pump shell and a rear end cover which are sequentially and coaxially arranged along a shaft axis; an oil outlet is formed in the upper portion of the pump shell, an annular groove is formed in the pump shell, and the oil outlet is communicated with the annular groove; the front end cover is fixed on the left end surface of the pump shell, the rear end cover is fixed on the right end surface of the pump shell, and the center of the end surface of the rear end cover is provided with an oil suction port;

the pump assembly comprises a pump core assembly, a left guide rail assembly and a right guide rail assembly; the pump core assembly comprises a pump core cylinder body assembly and a piston assembly;

the pump core cylinder body assembly comprises a pair of high-pressure columns and a pair of low-pressure columns, the high-pressure columns are arranged along a first diameter of the pump core cylinder body, the low-pressure columns are arranged along a second diameter of the pump core cylinder body, and the first diameter and the second diameter are perpendicular to each other and are positioned at different positions of an axial line; a through hole is formed in the radial direction of the high-pressure column, and a U-shaped groove is formed in the position, close to the center of the cylinder body, of the low-pressure column; the high-pressure column is communicated with the annular groove; a pair of oil outlet holes and a pair of oil inlet holes are formed in the inner ring of the cylinder body, and the oil outlet holes and the oil inlet holes are rectangular holes which are circumferentially and alternately distributed; the cylinder body outer ring is provided with a pair of left mounting holes for mounting a high-pressure column and a pair of right mounting holes for mounting a low-pressure column; the oil outlet hole is communicated with the left mounting hole, and the oil inlet hole is communicated with the right mounting hole; the oil outlet is communicated with the through hole of the high-pressure column, and the oil inlet is communicated with the U-shaped groove of the low-pressure column; the pair of high-pressure columns are inserted into the left mounting hole and are respectively connected with the second cone roller through the bearings, and the second cone roller moves in a matched manner with the left guide rail assembly; the pair of low-pressure columns are inserted into the right mounting hole and are respectively connected with a first conical roller through a bearing, and the first conical rollers and the right guide rail assembly move in a matched mode;

the piston assembly is arranged in the inner ring of the piston cylinder assembly along the axial lead direction; the piston assembly comprises a piston, a concentric ring, a transmission shaft, a left piston ring and a right piston ring; the concentric ring inner ring is provided with a pair of high-pressure holes and a pair of low-pressure holes, the high-pressure holes and the low-pressure holes are rectangular holes which are circumferentially and alternately distributed, and the width of the high-pressure holes and the width of the low-pressure holes are consistent with that of the oil inlet holes and the oil outlet holes on the inner ring of the pump core cylinder body; the low-pressure hole is communicated with the oil inlet hole, and the high-pressure hole is communicated with the oil outlet hole; the outer ring of the concentric ring is in interference fit with the inner ring of the pump core cylinder body; a pair of first distributing grooves and a pair of second distributing grooves are alternately and uniformly distributed on the wall surface of the piston in the circumferential direction, the first distributing grooves and the second distributing grooves are U-shaped grooves with opposite axial directions, and the width of the first distributing grooves is consistent with that of the high-pressure holes and the low-pressure holes; the outer ring of the piston and the inner ring of the concentric ring are in clearance fit and can move circumferentially and axially relative to the concentric ring; the piston is axially provided with a through hole, and two ends of the piston are provided with rectangular keys for mounting the left guide rail and the right guide rail; the transmission shaft is in clearance fit with the through hole of the piston and can axially move relative to the piston; two ends of the transmission shaft are provided with rectangular keys for mounting a left balance guide rail and a right balance guide rail;

the piston, the left piston ring and the concentric ring surround to form a left closed cavity; one side close to the piston cylinder body is taken as the inner side, and the inner side of the left piston ring is in a circular structure and is sleeved on the step on the left side of the piston; the outer ring of the annular structure is flush with the outermost circle of the piston and is in clearance fit with the inner ring of the concentric ring, and the inner ring is in clearance fit with the step on the left side of the piston; the piston, the right piston ring and the concentric ring are encircled to form a right closed cavity, and the sealing mode of each component is the same as that of the left closed cavity; the right closed cavity is always communicated with the first distribution groove, and the left closed cavity is always communicated with the second distribution groove;

the left guide rail assembly comprises a left guide rail and a left balance guide rail, and the right guide rail assembly comprises a right guide rail and a right balance guide rail; the left guide rail and the right guide rail are arranged at two ends of the piston, the left guide rail, the right guide rail and other equal deceleration curved surfaces are respectively matched with the second conical roller and the first conical roller to move, and the highest point and the lowest point on the equal deceleration curved surfaces of the left guide rail and the right guide rail correspond to each other; the left balance guide rail and the right balance guide rail are arranged at two ends of the transmission shaft, the left balance guide rail, the right balance guide rail and other equal deceleration curved surfaces are matched with the second cone roller and the first cone roller to move, and the highest point and the lowest point on the equal deceleration curved surfaces of the left balance guide rail and the right balance guide rail correspond to each other; the left balance guide rail and the right balance guide rail are respectively sleeved outside the left guide rail and the right guide rail, have the same shape with the left guide rail, the right guide rail and other equal deceleration curved surfaces and are circumferentially staggered by 90-degree phase angles; the mass sum of a balance rotor consisting of the left balance guide rail, the right balance guide rail and the transmission shaft is equal to the mass sum of a rotor consisting of the left guide rail, the right guide rail and the piston; when the left track and the right track drive the piston to do equal deceleration motion, the left balance track and the right balance track drive the transmission shaft to do equal deceleration motion in the circumferential direction in the same direction and in the axial direction in the opposite direction, and inertia force caused by axial motion of the rotor is offset;

the left end of the coupling assembly is axially fixed with the front end cover through a bearing and a sealing piece, the right end of the coupling assembly is connected with a left guide rail assembly in the pump core assembly through a shifting fork structure, and the coupling assembly and the left guide rail assembly of the pump core assembly move axially relative to each other while synchronously rotating;

the axial direction refers to the direction of the central axis of the piston; the radial direction refers to the diameter direction of the cross section of the piston; the circumferential direction refers to a direction of rotation around a central axis of the piston;

oil enters a right cavity of the pump shell from an oil suction port of the rear end cover, the left end of the right cavity is sealed by the pump core cylinder body assembly and the pump shell through a sealing ring, and the right end of the right cavity is sealed by the rear end cover and the pump shell through a sealing ring; oil enters the low-pressure holes of the concentric rings through the U-shaped grooves of the low-pressure columns;

the front end cover is fixedly connected to the left end face of the pump shell through a bolt, and the rear end cover is fixedly connected to the right end face of the pump shell through a bolt.

2. The heavy-duty, force-balanced, two-dimensional piston monoblock pump of claim 1, wherein: the pump core cylinder body assembly is fixed inside the pump shell through threaded connection.

3. The heavy-duty, force-balanced, two-dimensional piston monoblock pump of claim 1, wherein: a left concentric ring is arranged between the left piston ring and the piston, and a right concentric ring is arranged between the right piston ring and the piston; the left side of the left concentric ring is provided with a left retainer ring, and the right side of the right concentric ring is provided with a right retainer ring.

4. The heavy-duty, force-balanced, two-dimensional piston monoblock pump of claim 1, wherein: a pair of radial mounting holes are respectively formed in the U-shaped structures on the outer sides of the left piston ring and the right piston ring, and a pair of radial mounting holes are respectively formed in the left balance guide rail and the right balance guide rail in the guide rail assembly; the left piston ring is fixed on the left balance rail by penetrating two pins into a U-shaped structure on the outer side of the left piston ring and a radial mounting hole on the left balance rail; the fixing mode of the right piston ring and the right balance guide rail is the same as that of the left piston ring and the left balance guide rail.