CN101315068A

CN101315068A - Electrohydraulic proportion variable axial plunger pump

Info

Publication number: CN101315068A
Application number: CNA2008100631484A
Authority: CN
Inventors: 吴平
Original assignee: NINGBO HILEAD HYDRAULIC MACHINERY MANUFACTURING Co Ltd
Current assignee: NINGBO HILEAD HYDRAULIC MACHINERY MANUFACTURING Co Ltd
Priority date: 2008-07-11
Filing date: 2008-07-11
Publication date: 2008-12-03
Anticipated expiration: 2028-07-11
Also published as: CN101315068B

Abstract

An electro-hydraulic proportional variable axial plunger pump comprises a plunger pump body (100) and a variable mechanism (101) arranged at one side of the variable mechanism (101). The variable mechanism (101) comprises a variable shell (4), a variable piston (3), a variable head (5), a servo-valve housing (6), a servo-valve spool (7), a first flange (9), a positioning spring (10), a control flange (16), a proportional relief valve (15), etc. Compared with the prior art, the inventive axial plunger pump has the advantages of high entire operation reliability, high repetition accuracy, stepless variable implementation, lower oil cleanliness requirement, concise control mechanism, flexible action, relatively lower manufacturing cost, and high product cost performance.

Description

Electrohydraulic proportion variable axial plunger pump

Technical field

The present invention relates to a kind of cam-type axial piston pump, relate in particular to a kind of electrohydraulic proportion variable axial plunger pump.

Background technique

At the seventies in last century, in order to save the energy, external hydraulic transmission control system transfers research to by the pump displacement controlled hydraulic system by traditional valve control hydraulic system, afterwards in the hydraulic system, novel axial variable displacement plunger pump is able to a large amount of uses, for important function has been played in the national economic development.It is easy because of controlling to particularly point out the electric-hydraulic proportion axial piston pump, is active in one's movements, and the repeatability height can be realized advantages such as stepless variable, and application is the most extensive.

But some at present used electric-hydraulic proportion axial piston pump is by the allocation ratio servovalve, displacement transducer, programmable controller constitutes a closed circuit to be regulated, but the price that it is expensive, harsh oil cleanliness, complicated control mechanism restricts it and popularizes on a large scale, is Chinese utility model patent " electrichydraulic control formula the high-pressure plunger pump " (notice of authorization number: CN2578556Y) of ZL02253252.8 as the patent No..

Some electric-hydraulic proportion axial piston pump passing ratio electromagnet, proportional electromagnetic valve, pilot valve are regulated, with reference to Chinese utility model patent: ZL200320123474.2, a kind of " internal controlling electrohydraulic proportion variable axial plunger pump " (notice of authorization number: CN2667194Y) is disclosed, this patent variable partly adopts the mobile upper and lower cavity that makes the oily entering variable piston in the reduction valve of the electrorheological chemical control system pilot valve of proportion electro-magnet, thereby makes the variable piston up-down come the motion of controlled variable head to realize the variable of pump.And for example the patent No. is Chinese utility model patent " the axial variable plunger pump " (notice of authorization number: CN200952456Y) adopted proportional electromagnetic valve and internal control oil circuit to realize of ZL200620079670.8.Though above-mentioned patent structure is simple, it is limited by self-characteristic, and it is unreliable for repeatability, is difficult to satisfy actual usage requirement.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of proportion of utilization reduction valve regulating tie bar to move the electrohydraulic proportion variable axial plunger pump of control pump variable at above-mentioned prior art present situation.

The present invention solves the problems of the technologies described above the technological scheme that is adopted: a kind of electrohydraulic proportion variable axial plunger pump comprises the plunger pump main body and is located at the stroking mechanism of this plunger pump main body one side that described stroking mechanism comprises

Variable shell;

The variable piston has inner chamber, is located in the aforementioned variable shell, and its moving direction is vertical with the plunger motion direction in the described plunger pump main body;

The variable head is located at aforementioned variable shell one side, and an end is connected with aforementioned variable piston, and the other end is positioned at described plunger pump main body,

It is characterized in that described stroking mechanism also comprises

First flange is located at aforementioned variable shell upper end portion;

Control flange is located at the aforementioned first flange upper end portion;

Control piston is located in the aforementioned control flange and can be moved up and down;

Proportional pressure-reducing valve is arranged on the aforementioned control flange, is used to control oil and flows to;

Servo valve pocket is located in the aforementioned variable piston cavity;

Servo spool also can move up and down through aforementioned servo valve pocket, is used to drive aforementioned variable piston motion;

Pull bar, in aforementioned first flange, the underpart is connected with aforementioned servo spool, and the upper end portion contacts with aforementioned control piston lower end surface;

Spring seat is located in aforementioned first flange and is fixed on the aforementioned pull bar; And

Retaining spring is located in aforementioned first flange, and an end and aforementioned spring seat offset, and the other end then offsets with aforementioned first flange inner wall.

Described variable piston upper end-hole is provided with a baffle plate that can supply described pull bar to pass through, this baffle plate is limited in described servo valve pocket and servo spool in the inner chamber of variable piston, the design of baffle plate can spacing servo valve pocket and servo spool, plays the pull bar leading role that moves up and down simultaneously.

Described retaining spring is circular cross-section cylinder rotation pressure spring, and it is stable to have rigidity, and characteristic line is linear feature, creates conditions for stepless variable is provided.

Further optimal design, described pull bar is positioned at described spring seat upper end portion and also is bolted with surely nut admittedly, described variable shell underpart also is provided with second flange, and this second flange interior also is provided with one and is used to limit the spacing piston that described variable piston continues motion.

As decision design, described proportional pressure-reducing valve is the three-way valve with P mouth, A mouth and T mouth, accordingly, has the P mouth, A mouth and the T mouth that are connected conducting with described proportional pressure-reducing valve on the described control flange end face.

Described plunger pump main body can comprise

The pump housing;

Pump case is located between the described variable shell and the aforementioned pump housing;

The backhaul dish is located on the described variable head;

Plunger piston slippery boots is positioned in aforementioned pump case and is located at aforementioned backhaul dish through hole;

Transmission shaft is installed in the aforementioned pump housing by the bearing rotary type;

Housing assembly is positioned at aforementioned pump case and connects and rotate with transmission shaft with aforementioned transmission shaft;

Plunger is arranged between aforementioned housing assembly and the plunger piston slippery boots.

Compared with prior art, the invention has the advantages that: the oil pressure of proportional pressure-reducing valve output control oil is followed input current and is changed, possesses splendid linear relationship, when retaining spring rotates pressure spring for the circular cross-section cylinder, it is stable to have rigidity, and characteristic line is linear feature, rests on the arbitrary position by both in conjunction with can the stable regulation pull bar following input current signal, realize stepless variable, so this electric-hydraulic proportion axial piston pump has the repeatability height; While overall operation reliability height, oil cleanliness requires to reduce, and control mechanism is succinct, is active in one's movements, and manufacture cost is also relatively low, possesses high product price ratio.

Description of drawings

Fig. 1 is the example structure schematic representation.

Fig. 2 is along C-C direction sectional view among Fig. 1.

Embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

Embodiment: with reference to illustrated in figures 1 and 2, the electrohydraulic proportion variable axial plunger pump in the present embodiment comprises plunger pump main body 100 and is located at the stroking mechanism 101 of these plunger pump main body 100 1 sides.

Plunger pump main body 100 comprises the pump housing 21, pump case 17, plunger piston slippery boots 30, transmission shaft 24, oil distribution casing 20, housing assembly 19 and plunger 31 again.Stroking mechanism 101 comprises variable shell 4, variable piston 3, variable head 5, servo valve pocket 6, servo spool 7, baffle plate 8, first flange 9, control flange 16, control piston 14, pull bar 11, spring seat 12, nut 13, retaining spring 10, proportional pressure-reducing valve 15, second flange 1 and spacing piston 2 admittedly surely again.

Pump case 17 is connected with the pump housing 21 usefulness socket head screws, and pump case 17 is located between the variable shell 4 and the pump housing 21, and plunger piston slippery boots 30 is positioned in pump case 17 and is located on the variable head 5.

Transmission shaft 24 is installed in the pump housing 21 by bearing 22 rotary types, and this bearing 22 then is installed in the pump housing 21, and present embodiment middle (center) bearing 22 adopts radial ball bearing, and bearing 22 outer side compressions have flange plate 23.

Housing assembly 19 is positioned at pump case 17 and rotates with transmission shaft 24 connections and with transmission shaft 24, is provided with needle bearing 18 between housing assembly 19 and the pump case 17, and housing assembly 19 adopts rectangular splines to connect with transmission shaft 24.Oil distribution casing 20 is contained between the housing assembly 19 and the pump housing 21, have groove in the housing assembly 19, be provided with overcoat 25 in this groove, overcoat 25 endoporus are equiped with central spring 26, cover 27 in central spring 26 1 ends are provided with, cover 27 withstands on steel ball 28 on the backhaul dish 29 of being located at variable head 5 in this.

Plunger 31 is arranged between housing assembly 19 and the plunger piston slippery boots 30, can rotate with housing assembly 19.

Variable piston 3 is located in the variable shell 4, have inner chamber, the moving direction of variable piston 3 is vertical with plunger 31 moving direction in the plunger pump main body 100, and variable head 5 is located at variable shell 4 one sides, one end is connected with variable piston 3, and the other end is positioned at plunger pump main body 100 and has plunger piston slippery boots 30.

Servo valve pocket 6 is located in variable piston 3 inner chambers, and servo spool 7 wears servo valve pocket 6 through holes and can moving up and down, and baffle plate 8 has through hole, the inner chamber that it is located at variable piston 3 upper end portions and servo valve pocket 6 and servo spool 7 is limited in variable piston 3.

First flange 9 is located at variable shell 4 upper end portions, pull bar 11 is located in first flange 9, pull bar 11 underparts are connected with servo spool 7, the upper end portion contacts with control piston 14 lower end surfaces, spring seat 12 is located in first flange 9 and is fixed on the pull bar 11, surely nut 13 is bolted on the pull bar 11 and is positioned at spring seat 12 upper end portions admittedly, retaining spring 10 is located in first flange 9, one end and the spring seat 12 of retaining spring 10 offset, the other end and first flange, 9 inwalls offset, and retaining spring 10 is circular cross-section cylinder rotation pressure spring.

Control flange 16 has P mouth, A mouth and T mouth, control flange 16 is located at first flange, 9 upper end portions, control piston 14 is located in the control flange 16 and can be moved up and down, proportional pressure-reducing valve 15 also has P mouth, A mouth and T mouth, and the P mouth of proportional pressure-reducing valve 15, A mouth and T mouth P mouth, A mouth and the T mouth of corresponding control flange 6 respectively are provided with.

Second flange 1 is located at variable shell 4 underparts, spacing piston 2 be arranged at second flange 1 in be used for dominated variable piston 3 and continue motion and play position-limiting action.

The working principle of present embodiment plunger pump main body 100: transmission shaft 24 is rotated by driven by motor, transmission shaft 24 drives housing assembly 19 rotations, drive of the center line rotation of a plurality of plunger piston slippery boots 30 simultaneously around transmission shaft 24, central spring 26 is pressed on plunger piston slippery boots 30 on the variable head 5 that becomes certain angle of inclination with axis by interior cover 227, steel ball 28, backhaul dish 29, at this moment, a plurality of plunger piston slippery boots 30 are made axially reciprocating simultaneously in housing assembly 19, finish oil suction and press oily do action.

Stroking mechanism 101 working principles are: when proportional pressure-reducing valve 15 input currents during less than 100mA, the sealing of proportional pressure-reducing valve 15 spools, control oil does not enter the A mouth of control flange 16, control piston 14 unable acting on the pull bar 11 then, 11 on pull bar is subjected to retaining spring 10 and acts on power on the spring seat 12, make pull bar 11 move upward and be parked in minimum position, at this moment the discharge capacity minimum up to variable piston 3; When proportional pressure-reducing valve 15 input currents are heightened in proportion to 100～800mA, proportional pressure-reducing valve 15 spools are opened gradually, control oil enters the A mouth of control flange 16, control-oil pressure ` increases also corresponding proportional increase with input current, thereby act on the corresponding proportional increase of power of pull bar 11 heads by control piston 14, pushing drawing rod 11 does not stop to move downward up to reaching the equilibrium of forces state with retaining spring 10.Pull bar 11 drives variable piston 3 and moves downward, and the stepless variable of plunger pump is realized from small to large in the oblique angle of Moderator Variable head 5.Because the oil pressure of passing ratio reduction valve 15 output control oil is followed input current and is changed, possesses splendid linear relationship, and 10 of retaining springs are as circular cross-section cylinder rotation pressure spring, it is stable to have rigidity, characteristic line is linear feature, rests on the arbitrary position by both in conjunction with can stable regulation pull bar 11 following input current signal, so present embodiment has the repeatability height, good reliability, the characteristic of action response sensitivity.

Claims

1, a kind of electrohydraulic proportion variable axial plunger pump comprises plunger pump main body (100) and is located at the stroking mechanism (101) of these plunger pump main body (100) one sides that described stroking mechanism (101) comprises

Variable shell (4);

Variable piston (3) has inner chamber, is located in the aforementioned variable shell (4), and its moving direction is vertical with plunger (31) moving direction in the described plunger pump main body (100);

Variable head (5) is located at aforementioned variable shell (4) one sides, and an end is connected with aforementioned variable piston (3), and the other end is positioned at described plunger pump main body (100),

It is characterized in that described stroking mechanism (101) also comprises

First flange (9) is located at aforementioned variable shell (4) upper end portion;

Control flange (16) is located at aforementioned first flange (9) upper end portion;

Control piston (14) is located in the aforementioned control flange (16) and can be moved up and down;

Proportional pressure-reducing valve (15) is arranged on the aforementioned control flange (16), is used to control oil and flows to;

Servo valve pocket (6) is located in aforementioned variable piston (3) inner chamber;

Servo spool (7) also can move up and down through aforementioned servo valve pocket (6), is used to drive aforementioned variable piston (3) motion;

Pull bar (11), in aforementioned first flange (9), the underpart is connected with aforementioned servo spool (7), and the upper end portion contacts with aforementioned control piston (14) lower end surface;

Spring seat (12) is located in aforementioned first flange (9) and is fixed on the aforementioned pull bar (11); And

Retaining spring (10) is located in aforementioned first flange (9), and an end and aforementioned spring seat (12) offset, and the other end then offsets with aforementioned first flange (9) inwall.

2, electrohydraulic proportion variable axial plunger pump according to claim 1, it is characterized in that described variable piston (3) upper end-hole is provided with a baffle plate (8) that can supply described pull bar (11) to pass through, this baffle plate (8) is limited in described servo valve pocket (6) and servo spool (7) in the inner chamber of variable piston (3).

3, electrohydraulic proportion variable axial plunger pump according to claim 1 is characterized in that described retaining spring (10) is circular cross-section cylinder rotation pressure spring.

4, electrohydraulic proportion variable axial plunger pump according to claim 1 is characterized in that described pull bar is positioned at described spring seat (12) upper end portion and also is bolted with surely nut (13) admittedly.

5, electrohydraulic proportion variable axial plunger pump according to claim 1, it is characterized in that described variable shell (4) underpart also is provided with second flange (1), this second flange (1) interior also is provided with one and is used to limit the spacing piston (2) that described variable piston (3) continues motion.

6, electrohydraulic proportion variable axial plunger pump according to claim 1, it is characterized in that described proportional pressure-reducing valve (15) is for having the three-way valve of P mouth, A mouth and T mouth, accordingly, have P mouth, A mouth and the T mouth that is connected conducting with described proportional pressure-reducing valve (15) on described control flange (16) end face.

7,, it is characterized in that described plunger pump main body comprises according to the described electrohydraulic proportion variable axial plunger pump of the arbitrary claim of claim 1 to 6

The pump housing (21);

Pump case (17) is located between the described variable shell (4) and the aforementioned pump housing (21);

Backhaul dish (29) is located on the described variable head (5);

Plunger piston slippery boots (30) is positioned in aforementioned pump case (17) and is located at aforementioned backhaul dish (29) through hole;

Transmission shaft (24) is installed in the aforementioned pump housing (21) by bearing (22) rotary type;

Housing assembly (19) is positioned at aforementioned pump case (17) and connects and rotate with transmission shaft with aforementioned transmission shaft (24);

Plunger (31) is arranged between aforementioned housing assembly (19) and the plunger piston slippery boots (30).