CN210371062U

CN210371062U - Roller type force balance unit pump

Info

Publication number: CN210371062U
Application number: CN201920178099.2U
Authority: CN
Inventors: 阮健; 钱家圆; 童成伟; 黄煜; 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: 2020-04-21
Anticipated expiration: 2029-01-31

Abstract

The rolling wheel type force balance unit pump is provided with a rolling bearing between the right coupler and the right side roller assembly; the left cam and the right cam are symmetrically distributed on two sides of the pump core assembly, and the phase difference is 90 degrees; the roller components roll on the cam surface, four conical rollers are distributed on one side, two groups of copper sleeves of the pump core components which are fixed on the C-shaped roller bracket by using pin shafts are arranged on the cylinder body, and two pairs of rectangular high-low pressure oil holes which are uniformly distributed in the circumferential direction are formed on the copper sleeves and the cylinder body and are respectively contacted with the first flow distribution groove and the second flow distribution groove on the piston to suck and discharge oil; the cylinder body is provided with an annular oil groove communicated with the high-pressure oil holes, and oil liquid flowing out of the two high-pressure oil holes is gathered together; the rotor mass formed by the first roller bracket assembly, the third roller bracket assembly, the transmission shaft and the left and right concentric rings is equal to the sum of the rotor mass formed by the second roller group, the fourth roller bracket assembly and the piston; a first high-low pressure cavity in the pump core is always communicated with a first flow distribution groove of the piston, and a second high-low pressure cavity is always communicated with a second flow distribution groove of the piston.

Description

Roller type force balance unit 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 a power element of a hydraulic system, can transmit mechanical energy of a prime motor or other external energy to liquid, increases the energy of the liquid, and is widely applied to engineering machinery and aerospace. The traditional plunger pump has the problems of low efficiency, large vibration, high noise, short service life and the like due to the limitations of friction pairs, size and the like, and the aims of high speed and high pressure are difficult to realize.

The conventional common axial plunger pump has many internal relatively-moving parts, high requirements on material and processing precision, sensitivity to oil pollution, high requirements and cost on processing, use and maintenance 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 friction pair in the cylinder body is more, the temperature rise of the cylinder body is faster under the high-speed rotation, and the abrasion of parts such as a valve plate, a plunger and the like directly influences the service life and the durability of the pump. In addition, due to the limitation of the working principle of the plunger pump, the transmission shaft rotates for a circle, each plunger can only realize oil absorption and oil discharge once, and the displacement of the plunger is limited.

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.

Disclosure of Invention

In order to overcome the defects of the conventional two-dimensional 2D piston pump, the invention provides the roller type force balance unit pump which utilizes the double degrees of freedom of the piston and can axially move while the plunger rotates so as to realize the continuous oil suction and discharge function.

The technical implementation scheme of the invention is as follows:

a roller type force balance unit pump is characterized in that a right end cover, a right coupler assembly, a right roller assembly, a right cam, a pump shell, a pump core assembly, a left cam, a left roller assembly, a left coupler assembly and a left end cover are sequentially distributed along the axis direction. The left end cover and the right end cover are coaxially distributed with the left coupler and the right coupler and are isolated by adopting rolling bearings. And a rolling bearing is arranged between the right coupler and the right roller assembly to prevent direct contact with the right roller assembly. The left cam and the right cam are symmetrically distributed on two sides of the pump core assembly, and the phase difference is 90 degrees. The roller components roll on the cam surface, four cone rollers are distributed on one side, two groups of pin shafts are fixed on the C-shaped roller bracket, a group of rollers which are in contact with the right cam and face towards the cam surface from the C-shaped opening are first roller bracket components, each first roller bracket component comprises a pair of cone rollers which are symmetrically distributed along the axis of the pump core, the C-shaped roller bracket component, a rolling bearing and a fixed pin shaft, a group of rollers which are in contact with the right cam and face away from the C-shaped opening are second roller bracket components, and each second roller bracket component comprises a pair of cone rollers which are symmetrically distributed along the axis of the pump core, a roller bracket, a rolling bearing and a fixed pin shaft. And the two groups of roller bracket assemblies circumferentially fix axial relative motion. The roller is fixed on the roller frame in a mode of a pin shaft. And a group of rollers which are in contact with the left cam and have C-shaped openings facing the cam surface is a third roller bracket assembly, and a group of rollers which are in contact with the left cam and have C-shaped openings departing from the cam surface is a fourth roller bracket assembly. The second roller bracket assembly and the fourth roller bracket assembly are fixed on the piston in a spline mode, and the first roller bracket assembly and the third roller bracket assembly are fixed on the transmission shaft in a spline mode. The mounting mode and the motion mode of the third roller bracket component are consistent with those of the first roller bracket component, and the fourth roller component is consistent with that of the second roller component. The installation phase angle difference of the first roller bracket assembly and the second roller bracket assembly is 90 degrees, the phase positions of the first roller bracket assembly and the third roller bracket assembly are the same, and the phase positions of the second roller bracket assembly and the fourth roller bracket assembly are the same.

The pump core assembly comprises a cylinder body, a piston, a copper sleeve, a transmission shaft, a left concentric ring and a right concentric ring. And two ends of the piston are made into spline shaft forms to fix the second roller bracket assembly and the fourth roller bracket assembly. The piston wall surface is provided with a pair of first distributing grooves and a pair of second distributing grooves which are alternately and uniformly distributed, the first distributing grooves and the second distributing grooves are U-shaped distributing grooves with opposite axial openings, and the width of the U-shaped distributing grooves is consistent with that of rectangular holes in the copper sleeve. The left concentric ring and the right concentric ring are respectively sleeved on steps on two sides of the piston, the mounting directions are opposite in axial direction, and the left concentric ring and the right concentric ring are fixed on the first roller bracket assembly and the third roller bracket assembly through fixing pin shafts. The excircle of the transmission shaft is in clearance fit with the inner circle of the piston, and the transmission shaft and the piston move axially and relatively. The two ends of the transmission shaft are made into spline shaft forms to fix the first roller bracket assembly and the third roller bracket assembly. Two pairs of rectangular high-low pressure oil holes are circumferentially and uniformly distributed on the copper sleeve and the cylinder body and are respectively contacted with the first flow distribution groove and the second flow distribution groove on the piston to suck and discharge oil. The cylinder body is provided with an annular oil groove communicated with the high-pressure oil holes, and oil liquid flowing out of the two high-pressure oil holes is gathered together.

The rotor mass formed by the first roller bracket assembly, the third roller bracket assembly, the transmission shaft and the left and right concentric rings is equal to the sum of the rotor mass formed by the second roller group, the fourth roller bracket assembly and the piston, and the inertia force generated by acceleration is balanced on the cam.

A left side face of a right concentric ring, the outer surface of a piston and the inner side face of a copper sleeve in the pump core form a first high-low pressure cavity, a right side face of the left concentric ring, the outer surface of the piston and the inner side face of the copper sleeve form a second high-low pressure cavity, inner circles of the left concentric ring and the right concentric ring are in clearance fit with the piston, and outer circles of the left concentric ring and the right concentric ring are in clearance fit with the inner side face of the copper sleeve to form. The first high-low pressure cavity is always communicated with the first flow distribution groove of the piston, and the second high-low pressure cavity is always communicated with the second flow distribution groove of the piston.

In the process that the first roller bracket assembly moves from the lowest point to the highest point of the right cam, the first roller bracket assembly drives the concentric rings to rotate in the same direction and move rightwards, the second roller bracket assembly moves from the highest point to the lowest point of the right cam and drives the piston to move leftwards, and a first distributing groove in the piston is communicated with the oil suction holes in the copper sleeve and the cylinder body to suck oil into the first high-low pressure cavity. The first roller bracket assembly rotates and simultaneously drives the transmission shaft to synchronously rotate and move rightwards through the spline, the movement is transmitted to the third roller bracket assembly, and the third roller bracket assembly moves to the lowest point from the highest point of the left cam to drive the left concentric ring to move rightwards. The second roller bracket assembly transmits the motion to the fourth roller bracket assembly through a spline on the piston, drives the piston to move leftwards, reduces the volume in the second high-low pressure cavity, and discharges oil from the oil outlet through a second flow distribution groove on the piston. Along with the rotation movement of the roller component, the oil suction holes and the oil discharge holes on the first distributing groove, the second distributing groove and the concentric rings are periodically changed, so that the oil suction and discharge of the roller type inertia force balancing unit are realized.

Furthermore, the left end cover is fixed on the left side surface of the pump shell through a bolt, and the right end cover is fixedly connected on the right end surface of the pump shell through a bolt. The left end cover, the right end cover and the pump shell are sealed by sealing rings. The cylinder body is fixedly connected to the right end face of the pump shell through bolts, and the cylinder body and the pump shell are sealed through a sealing ring.

Furthermore, the suction and discharge oil hole on the copper bush and the suction and discharge oil hole on the cylinder body are completely consistent in position, and the outer circle of the copper bush and the inner circle of the cylinder body are fixed in an interference fit mode.

The invention has the following beneficial effects:

1. the volume change is completed by the cooperation of the piston and the concentric rings, which is doubled compared with the volume change of a single piston, and the space is saved. When the stroke and the discharge capacity are not changed, the cross-sectional area is reduced, the stress of the guide rail and the conical roller is reduced, and high load is easy to realize.

2. The mode that the gyro wheel is rotatory is adopted, compares cam rotation type force balance unit pump simple structure, has greatly strengthened the motion reliability.

3. The inertia force of different roller groups in opposite directions is utilized, the mass of different rotors is balanced, so that the inertia force on the cylinder body is balanced, the mechanical vibration during operation is reduced, the output rotating speed of the motor is more stable, and the flow pulsation is reduced. Meanwhile, the output torque of the motor can be reduced, and energy is saved.

4. Through special shaft coupling structure, with rotor part parcel in airtight intracavity, greatly reduced the rotor and rotated the oil loss that stirs that produces when producing, improved the mechanical efficiency of pump.

Drawings

FIG. 1 is a schematic view of the roller type force balance unit pump assembly of the present invention.

Fig. 2 is a schematic view of the internal assembly of the present invention.

Fig. 3 a-3 b are schematic views of a right coupling assembly of the present invention, wherein fig. 3a is an inside view of the right coupling assembly view and fig. 3b is an outside view of the right coupling assembly view.

Fig. 4 a-4 b are schematic views of the left coupling assembly of the present invention, wherein fig. 4a is an inside view of the left coupling assembly view and fig. 4b is an outside view of the left coupling assembly view.

Fig. 5 a-5 b are schematic structural views of the left end cap of the present invention, wherein fig. 5a is an external side view of the left end cap, and fig. 5b is an internal side view of the left end cap.

Fig. 6 is a schematic structural view of the right end cover of the present invention.

Fig. 7a to 7d are schematic views of a roller assembly according to the present invention, wherein fig. 7a is a schematic view of the roller assembly, fig. 7B is a schematic view of an end surface of the roller assembly, fig. 7C is a sectional view taken along line C-C of fig. 7B, and fig. 7d is a sectional view taken along line B-B of fig. 7B.

FIG. 8 is a schematic view of a concentric ring configuration of the present invention.

Fig. 9 is a schematic view of the piston structure of the present invention.

Fig. 10 is a schematic view of a propeller shaft structure of the present invention.

Fig. 11 is a schematic view of the truck assembly coupling arrangement of the present invention.

FIG. 12 is a schematic view of a pump cartridge assembly of the present invention.

Fig. 13a to 13c are schematic structural views of a cylinder block copper sheathing assembly of the present invention, fig. 13a is an end view of the cylinder block copper sheathing assembly, fig. 13b is a side view of the cylinder block copper sheathing assembly, and fig. 13c is a sectional view taken along line a-a of fig. 13 b.

Fig. 14a to 14c are schematic views showing the structure of the cam of the present invention, fig. 14a is a front view of the cam, fig. 14b is a side view of the cam, and fig. 14c is a rear view of the cam.

Fig. 15a to 15b are schematic views of a pump housing structure of the present invention, fig. 15a is a front view of the pump housing structure, and fig. 15b is a sectional view taken along line a-a of fig. 15 a.

Fig. 16a to 16e are different angle flow channel sectional views of the present invention, in which fig. 16a is a flow channel sectional view at a rotation angle of 0 °, fig. 16b is a flow channel sectional view at a rotation angle of 45 °, fig. 16c is a flow channel sectional view at a rotation angle of 90 °, fig. 16d is a flow channel sectional view at a rotation angle of 135 °, and fig. 16e is a flow channel sectional view at a rotation angle of 180 °.

Detailed Description

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

The roller type force balance unit pump of the present invention comprises: right shaft coupling subassembly 1R, right-hand member lid 3, left wheel subassembly 4L and right wheel subassembly 4R, pump core subassembly 5, pump case 6, left end lid 8, left shaft coupling 1L. The right end cover 3 is connected with the right end face of the pump shell 6 through a bolt, and the left end cover 8 is fastened on the left end face of the pump shell 6 through a bolt. The sealing between the right end cover 3 and the pump shell 6 and between the left end cover 8 and the pump shell 6 is mainly realized by a sealing ring 7. The right shaft coupling 1R and the right end cover 3 are axially positioned through the rolling ball bearing 10, the motion isolation of the right shaft coupling 1R and the right end cover 3 is realized through the rolling ball bearing 10, and the right shaft coupling 1R can complete rotary motion. The right coupler 1R and the right end cover 3 are sealed mainly by a gap, and the trapezoidal groove 2 on the right end cover 3 is used for preventing volatile harmful gas in oil from escaping. Four rolling bearings 12 are uniformly distributed on the inner wall surface of the right coupling component 1R and fixed on the coupler 11 through a pin shaft 13, and the right coupling component 1R is in contact with the right roller component 4R through the rolling bearings 12, so that relative sliding does not exist when the right roller component 4R and the right coupling component 1R do relative axial movement. Four rolling bearings 12 are embedded between the first roller bracket assembly 14 and the second roller bracket assembly 15.

The right roller assembly 4R includes a first roller bracket assembly 14, a second roller bracket assembly 15, and a right concentric ring 172. The first roller bracket assembly 14 includes a roller 144, a rolling bearing 1414, a first roller bracket 142, and a fixed pin 143. The roller 144 and the rolling bearing 141 are fixed to the first roller bracket 142 by a fixing pin 143. The first roller bracket assembly 14 is fixed on the transmission shaft 16 through a spline 16a, the right concentric ring 172 is fixed on the first roller bracket 141 through a pin hole 172a and a fixed pin 143, and the transmission shaft 16, the right concentric ring 172 and the first roller bracket assembly 14 are fixedly connected and move synchronously. The second roller bracket assembly 15 includes a rolling bearing 151, a second roller bracket 152, a fixing pin 153, and a roller 154. The rolling bearing 151 and the roller 154 are fixed to the second roller bracket 152 by a fixing pin. The second roller assembly 15 and the piston 18 are fixedly connected through a spline 18a and move synchronously. The first roller bracket assembly 14 and the second roller bracket assembly 15 rotate synchronously through circumferential constraint of the rolling bearing 12, but there is no axial constraint, i.e., the first roller bracket assembly 14 and the second roller bracket assembly 15 allow for relative axial movement. The mounting, positioning and movement relations of the right roller assembly 4R and the left roller assembly 4L are consistent, and two pairs of rollers in the same direction are regarded as the same assembly.

The pump core assembly 5 comprises a transmission shaft 16, a piston 18, a right concentric ring 172, a left concentric ring 171, a right cam 19R, a left cam 19L, a filter screen 20, a cylinder body 21 and a copper sleeve 22. The cylinder body 21 is fixed by bolts through the through holes 21a and the threaded holes 6a on the pump shell 6, and the positioning of the pump core assembly is realized. The right cam 19R has a positioning pin hole 19Ra, and is fixed to a positioning pin hole 21e of the cylinder block 21 by a positioning pin. According to the shape of the cam surface of the right cam 19R, the cam stroke can be divided into two parts, the lift is from the lowest point to the highest point, the return is from the highest point to the lowest point, the highest point is called a peak point, the lowest point is called a valley point, each cam has two peak points, two valley points, that is, each cam has two lift ranges, and two return ranges, each range is 90 °. The copper bush 22 is fixed in the inner ring of the cylinder block 21 by interference fit, and the high-pressure oil hole 22a and the low-pressure oil hole 22b in the copper bush 22 are respectively communicated with the high-pressure oil hole 21b and the low-pressure oil hole 21c in the cylinder block 21. An annular groove 21d in the cylinder 21 communicates with an oil discharge port 6b on the pump housing, and the oil can flow out from the two high-pressure oil holes 22a of the cylinder 21, and then converge together through the annular groove 21d and flow out from the oil discharge port 6b on the pump housing.

The roller type force balance unit pump left cam 19L and the right cam 19R are installed at a phase difference of 90 degrees, namely, the peak point of the left cam 19L is opposite to the valley point of the right cam 19R, the lift of the left cam 19L is opposite to the return stroke of the right cam 19R, the first roller bracket assembly 14 and the second roller bracket assembly 15 are installed at a phase difference of 90 degrees, when the first roller assembly 14 moves from the valley point to the peak point along the right cam 19R and simultaneously moves from the peak point to the valley point along the left cam 19L, the second roller assembly 15 moves from the peak point to the valley point along the left cam 19L and simultaneously moves from the valley point to the peak point along the right cam 19R. The left cam 19L and the right cam 19R are a pair of identical cams, the installation phase angles of which differ by 90 °, and the change laws of the cam curved surfaces are also identical. According to the equal-acceleration equal-deceleration motion law adopted by the cam curved surface, the first roller assembly 14 performs uniform rotation motion in the circumferential direction, and performs uniform acceleration motion at a fixed acceleration in the axial direction in the process of moving from a valley point to a peak point along the right cam curved surface, the speed direction is rightward, the acceleration path is a rotation angle of 45 degrees, then uniform deceleration motion starts to be performed, the acceleration direction is unchanged, the acceleration direction is leftward, the deceleration path is a rotation angle of 45 degrees, and the speed is just 0 as same as the valley point until the first roller assembly 14 reaches the peak point of the right cam 19R. The second roller bracket assembly 15 and the first roller bracket assembly 14 rotate synchronously, and in the process of moving from a valley point to a peak point along the curved surface of the left cam, the second roller bracket assembly 15 performs uniform acceleration motion at a fixed acceleration in the axial direction, the speed direction is leftward, the acceleration path is a rotation angle of 45 degrees, then uniform deceleration motion starts, the speed direction is unchanged, the acceleration direction is rightward, the deceleration path is a rotation angle of 45 degrees, and the speed is just 0 as same as the valley point until the second roller bracket assembly 15 reaches the peak point of the left cam 19L. The first roller bracket assembly 14 and the second roller bracket assembly 15 are subjected to the same acceleration and opposite directions during the movement process. When the sum of the masses of the first roller bracket assembly 14, the transmission shaft 16, the left concentric ring 171 and the right concentric ring 172 is equal to the sum of the masses of the second roller bracket assembly 15 and the piston 18, the inertial force of the first roller bracket assembly 14 acting on the cam is the same as the inertial force of the second roller bracket assembly acting on the cam in the same direction and opposite to the direction, and the inertial force indirectly acting on the cylinder body and the pump shell is counteracted to realize the balance of the inertial force.

The roller type force balance unit pump left end cover 8 is connected with an external oil circuit, hydraulic oil enters the interior of the pump shell through four waist-shaped holes 8a on the left end cover 8, is filled in a left cavity inside the left end cover 8, and on one hand, the oil enters a right cavity inside the right end cover 3 through connecting holes 21f on the cylinder body 21, and the oil in the two cavities can play a role in lubricating friction pairs. On the other hand, the oil liquid passes through the connecting hole 21f, the low-pressure oil hole 21c of the cylinder body and the low-pressure oil hole 22B on the copper bush, and enters the first high-low pressure cavity B or the second high-low pressure cavity A through the first distributing groove 18c or the second distributing groove 18B on the piston 18 connected with the low-pressure oil hole 22B on the copper bush. The high-pressure oil passes from the second high-pressure chamber a or the first high-pressure chamber B through the second distributing groove 18B or the first distributing groove 18c of the piston 18 and the high-pressure oil hole 22a and the high-pressure oil hole 21B connected thereto, enters the annular groove 21d of the cylinder 21, and is discharged out of the unit pump through the oil discharge port 6B of the pump housing 6. The second high-low pressure cavity A is a closed cavity formed by enclosing the inner circular surface of the copper sleeve 22, the right end surface of the left concentric ring 161 and the piston 18, and the first high-low pressure cavity B is a closed cavity formed by enclosing the inner circular surface of the copper sleeve 22, the left end surface of the right concentric ring 172 and the piston 18.

Principle of operation

Roller type force balance unit pump drives right shaft coupling subassembly 1R in the right-hand member lid 3 through external motor and rotates, and then drives first roller bracket component 14 and second roller bracket component 15 and do the synchronous revolution motion, first roller bracket component 14 moves to the right under the restraint of right cam 19R, drive right concentric ring 172 through fixed restraint round pin axle 143 and move to the right, second roller bracket component 15 moves to the left under the restraint of left cam 19L simultaneously, drive piston 18 through fixed connection 18a and move to the left, make first high-low pressure chamber B volume increase, second high-low pressure chamber A volume reduces. The oil external oil passage enters the left end cover 8, enters the left end cover through a kidney-shaped hole 8a in the left end cover 8, enters the low-pressure oil hole 22B in the copper bush 22 through connecting

holes

21f and 21c in the cylinder body 21, is connected with the low-pressure oil hole 22B in the copper bush through a first distributing groove 18c in the piston at the moment, and sucks oil into the first high-pressure and low-pressure cavity B through the first distributing groove 18 c. The volume of the second high-low pressure cavity A is reduced, so that the oil pressure in the second high-low pressure cavity A is increased, oil is pressed into the annular groove 22d through the second distributing groove 18b on the piston, the high-pressure oil hole 22a on the copper bush 22 and the high-pressure oil hole 21b on the cylinder body, and the oil is discharged through the oil discharge port on the pump shell 6.

When the angle is 45 degrees, the first roller bracket assembly 14 moves to the limit position under the restriction of the right cam 19R, namely, the rightmost end of the stroke, the second roller bracket assembly 15 moves to the leftmost end of the stroke under the restriction of the left cam 19L, at this time, the first high-low pressure cavity B is in the maximum volume state, the second high-low pressure cavity a is in the minimum volume state, the communication area of the second distributing groove 18B and the high-pressure oil hole 22a and the low-pressure oil hole 22B on the copper bush and the communication area of the first distributing groove 18c and the high-pressure oil hole 22a and the low-pressure oil hole 22B on the copper bush are zero. Then the first roller bracket assembly 14 moves leftwards under the constraint of the left cam 19L, and the second roller bracket assembly 15 moves leftwards under the constraint of the right cam 19R, so that the volume of the second high-low pressure chamber A is increased, and the volume of the first high-low pressure chamber B is reduced. The oil external oil passage enters the left end cover 8, enters the left end cover through a kidney-shaped hole 8a in the left end cover 8, enters the low-pressure oil hole 22b in the copper bush 22 through connecting

holes

21f and 21c in the cylinder body 21, at the moment, the second distributing groove 18b in the piston is connected with the low-pressure oil hole 22b in the copper bush, and the oil is sucked into the second high-pressure and low-pressure cavity A through the second distributing groove 18 b. The volume of the first high-low pressure cavity B is reduced, so that the oil pressure in the first high-low pressure cavity B is increased, oil is pressed into the annular groove 22d through the first distributing groove 18c on the piston, the high-pressure oil hole 22a on the copper bush 22 and the high-pressure oil hole 21B on the cylinder body, and the oil is discharged through the oil discharge port on the pump shell 6.

When the angle is rotated by 90 degrees, the first roller bracket assembly 14 and the second roller bracket assembly 15 are simultaneously in the middle position, and the second distributing groove 18b on the piston and the high-pressure oil hole 22a and the first distributing groove 18c on the copper bush are in the maximum contact state with the low-pressure oil hole 22b on the copper bush. The first roller bracket assembly 14 still moves leftwards under the constraint of the left cam 19L, and the second roller bracket assembly 15 still moves leftwards under the constraint of the right cam 19R, so that the volume of the second high-low pressure chamber a continues to increase, and the volume of the first high-low pressure chamber B continues to decrease.

When the rotation angle is 135 degrees, the first roller bracket assembly 14 moves to the leftmost end of the stroke under the restriction of the left cam 19L, the second roller bracket assembly 15 moves to the rightmost end of the stroke under the restriction of the right cam 19R, the second high-low pressure cavity A is in the maximum volume state at the moment, the first high-low pressure cavity B is in the minimum volume state at the moment, and at the moment, the communication area of the second distributing groove 18B and the high-pressure oil hole 22a and the low-pressure oil hole 22B on the copper bush and the communication area of the first distributing groove 18c and the high-pressure oil hole 22a and the low-pressure oil hole 22B on the copper bush are zero. The first roller bracket assembly 14 moves to the right under the constraint of the right cam 19R, and the second roller bracket assembly 15 moves to the left under the constraint of the left cam 19L, so that the first high-low pressure chamber B increases in volume and the second high-low pressure chamber a decreases in volume. The oil external oil passage enters the left end cover 8, enters the left end cover through a kidney-shaped hole 8a in the left end cover 8, enters the low-pressure oil hole 22B in the copper bush 22 through connecting

holes

And then the roller type force balance unit pump is driven by the motor to do the cyclic periodic motion, and when the motor rotates for one period, namely 360 degrees, the roller component of the roller type force balance unit pump completes the axial reciprocating motion completed twice, and the first high-low pressure cavity A and the second high-low pressure cavity B complete oil suction and discharge twice respectively.

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. Roller type force balance unit pump, its characterized in that: the pump comprises a pump body, a pump core assembly, a left cam, a left roller assembly, a left coupler assembly and a left end cover, wherein the right end cover, the right coupler assembly, the right roller assembly, the right cam and the pump body are sequentially distributed along the axis direction; the left end cover and the right end cover are coaxially distributed with the left coupler and the right coupler and are isolated by adopting rolling bearings; a rolling bearing is arranged between the right coupler and the right roller component; the left cam and the right cam are symmetrically distributed on two sides of the pump core assembly, and the phase difference is 90 degrees; the roller component rolls on the cam surface, four conical rollers are distributed on one side, two conical rollers are fixed on the C-shaped roller bracket in a group by using a pin shaft, the group of rollers which are in contact with the right cam and have C-shaped openings facing the cam surface is a first roller bracket component, the first roller bracket component comprises a pair of conical rollers, a C-shaped roller bracket, a rolling bearing and a fixed pin shaft which are symmetrically distributed along the axis of the pump core, the group of rollers which are in contact with the right cam and have C-shaped openings back to the cam surface is a second roller bracket component, and the second roller bracket component comprises a pair of conical rollers, a roller bracket, a rolling bearing and a fixed pin shaft which are symmetrically distributed along; the two groups of roller bracket assemblies are fixed in the circumferential direction and move relatively in the axial direction; the roller is fixed on the roller frame in a pin shaft mode; a group of rollers which are contacted with the left cam and have C-shaped openings facing the cam surface is a third roller bracket assembly, and a group of rollers which are contacted with the left cam and have C-shaped openings departing from the cam surface is a fourth roller bracket assembly; the second roller bracket assembly and the fourth roller bracket assembly are fixed on the piston in a spline form, and the first roller bracket assembly and the third roller bracket assembly are fixed on the transmission shaft in a spline form; the mounting mode and the movement mode of the third roller bracket assembly are consistent with those of the first roller bracket assembly, and the fourth roller assembly is consistent with that of the second roller assembly; the installation phase angle difference of the first roller bracket assembly and the second roller bracket assembly is 90 degrees, the phase positions of the first roller bracket assembly and the third roller bracket assembly are the same, and the phase positions of the second roller bracket assembly and the fourth roller bracket assembly are the same;

the pump core assembly comprises a cylinder body, a piston, a copper sleeve, a transmission shaft, a left concentric ring and a right concentric ring; two ends of the piston are made into spline shaft forms to fix the second roller bracket assembly and the fourth roller bracket assembly; the wall surface of the piston is provided with a pair of first distributing grooves and a pair of second distributing grooves, the first distributing grooves and the second distributing grooves are alternately and uniformly distributed, the first distributing grooves and the second distributing grooves are U-shaped distributing grooves with opposite axial openings, and the width of the U-shaped distributing grooves is consistent with that of rectangular holes in the copper sleeve; the left concentric ring and the right concentric ring are respectively sleeved on steps on two sides of the piston, the mounting directions are opposite in axial direction, and the left concentric ring and the right concentric ring are fixed on the first roller bracket component and the third roller bracket component by using a fixed pin shaft; the excircle of the transmission shaft is in clearance fit with the inner circle of the piston, and the transmission shaft and the piston move axially and relatively; two ends of the transmission shaft are made into spline shaft forms to fix the first roller bracket assembly and the third roller bracket assembly; two pairs of rectangular high-low pressure oil holes which are uniformly distributed in the circumferential direction are formed in the copper bush and the cylinder body and are respectively contacted with the first flow distribution groove and the second flow distribution groove on the piston to suck and discharge oil; the cylinder body is provided with an annular oil groove communicated with the high-pressure oil holes, and oil liquid flowing out of the two high-pressure oil holes is gathered together;

the mass of the rotor consisting of the first roller bracket assembly, the third roller bracket assembly, the transmission shaft and the left and right concentric rings is equal to the sum of the mass of the rotor consisting of the second roller group, the fourth roller bracket assembly and the piston, and the inertia force generated by acceleration is balanced on the cam;

a first high-low pressure cavity is formed by the left side surface of a right concentric ring in the pump core, the outer surface of the piston and the inner side surface of the copper sleeve, a second high-low pressure cavity is formed by the right side surface of the left concentric ring, the outer surface of the piston and the inner side surface of the copper sleeve, inner circles of the left concentric ring and the right concentric ring are in clearance fit with the piston, and outer circles of the left concentric ring and the right concentric ring are in clearance fit with the inner side surface of the; the first high-low pressure cavity is always communicated with a first flow distribution groove of the piston, and the second high-low pressure cavity is always communicated with a second flow distribution groove of the piston;

in the process that the first roller bracket assembly moves from the lowest point to the highest point of the right cam, the first roller bracket assembly drives the concentric rings to rotate in the same direction and move rightwards, while the second roller bracket assembly moves from the highest point to the lowest point of the right cam and drives the piston to move leftwards, a first distributing groove on the piston is communicated with the oil suction holes in the copper sleeve and the cylinder body, and oil is sucked into the first high-low pressure cavity; the first roller bracket assembly rotates and simultaneously drives the transmission shaft to synchronously rotate and move rightwards through the spline, the movement is transmitted to the third roller bracket assembly, and the third roller bracket assembly moves from the highest point to the lowest point of the left cam to drive the left concentric ring to move rightwards; the second roller bracket assembly transmits the motion to the fourth roller bracket assembly through a spline on the piston to drive the piston to move leftwards, the volume in the second high-low pressure cavity is reduced, and oil is discharged from the oil outlet through a second flow distribution groove on the piston; along with the rotation movement of the roller component, the oil suction holes and the oil discharge holes on the first distributing groove, the second distributing groove and the concentric rings are periodically changed, so that the oil suction and discharge of the roller type inertia force balancing unit are realized.

2. The roller type force balancing unit pump of claim 1, wherein: the left end cover is fixed on the left side surface of the pump shell through a bolt, and the right end cover is fixedly connected to the right end surface of the pump shell through a bolt; the left end cover, the right end cover and the pump shell are sealed by sealing rings; the cylinder body is fixedly connected to the right end face of the pump shell through bolts, and the cylinder body and the pump shell are sealed through a sealing ring.

3. The roller type force balance unit pump according to claim 1 or 2, wherein: the suction and exhaust oil hole on the copper sleeve is completely consistent with the suction and exhaust oil hole on the cylinder body in position, and the outer circle of the copper sleeve is fixed with the inner circle of the cylinder body in an interference fit mode.