CN205918969U - Gear pump control formula electro -hydraulic linkage actuating mechanism - Google Patents
Gear pump control formula electro -hydraulic linkage actuating mechanism Download PDFInfo
- Publication number
- CN205918969U CN205918969U CN201620670095.2U CN201620670095U CN205918969U CN 205918969 U CN205918969 U CN 205918969U CN 201620670095 U CN201620670095 U CN 201620670095U CN 205918969 U CN205918969 U CN 205918969U
- Authority
- CN
- China
- Prior art keywords
- oil
- hydraulic
- pump
- way gear
- port
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Fluid-Pressure Circuits (AREA)
Abstract
The utility model discloses a gear pump control formula electro -hydraulic linkage actuating mechanism, include: two -way gear oil pump, two -way gear oil pump is driven by servo motor, two hydraulic fluid ports of two -way gear oil pump are linked together with two P ports of hydraulic pressure lock through oil pipe respectively one to one, hydraulic pressure is locked and is linked together one to one with two cavities of hydro -cylinder through oil pipe respectively with two A ports of two P port one -to -ones, still including the buffer oil tank that just can not provide low pressure hydraulic oil with the atmosphere intercommunication, two hydraulic fluid ports of two -way gear oil pump are established ties respectively behind the check valve all and buffer oil tank's hydraulic fluid port is linked together, the drain tap of two -way gear oil pump is linked together with buffer oil tank's hydraulic fluid port through oil pipe. Foretell gear pump control formula electro -hydraulic linkage actuating mechanism response speed is fast and positioning accuracy is high, and its hydraulic circuit simple structure, and the energy consumption is low, the reliability is high.
Description
Technical field
This utility model is related to electrohydraulic actuator field and in particular to a kind of execution machine for electrohydraulic actuator
Structure.
Background technology
Electrohydraulic actuator is to receive control information in automation equipment and apply control action to controll plant
Device, usual controll plant is valve.At present, usually servo valve control formula is electro-hydraulic for the actuator in electrohydraulic actuator
Dynamic actuator, this kind of actuator is realized to controlled by controlling servo valve regulation running of hydraulic power oil direction and uninterrupted
The regulation of object, this kind of actuator generally adopts open cycle hydraulic circuit, and the power fluid force feed in hydraulic circuit is usual
There is provided by the Hydraulic Station in addition arranging, and this Hydraulic Station would generally give the electro-hydraulic linkage execution of several servo valve control formulas simultaneously
Mechanism provides hydraulic oil；Above-mentioned servo valve control formula electro-hydraulic actuating mechanism has the disadvantage that one, due to using in addition setting
The Hydraulic Station put provides power fluid force feed, and controls actuator by servo valve, leads to the hydraulic pressure of this actuator to return
Line structure is complicated, and volume is big, high energy consumption；2nd, the servo valve in actuator is very high to the purity requirements of fluid, but this is held
Row mechanism uses open cycle hydraulic circuit it may be assumed that hydraulic circuit and atmosphere, so fluid is easily dirty by external environment
Dye, thus this actuator is easily broken down, poor reliability, need to often safeguard.
Utility model content
Technical problem to be solved in the utility model is: will provide that a kind of hydraulic loop structure is simple, energy consumption is low, hydraulic pressure
Oil is difficult contaminated gear pump control type electrohydraulic linkage actuating mechanism.
In order to solve the above problems, the technical solution adopted in the utility model is: gear pump control type electrohydraulic linkage execution machine
Structure, comprising: two-way gear oil pump, is characterized in: two-way gear oil pump is driven by servomotor, wherein: two-way gear oil pump tool
Have that self-priming performance is good, the simple anti-pollution of efficiency high, structure, can bidirectional output high voltage power oil stream and output flow is basic and turn
The feature of rapid-result direct ratio；Servomotor has high direction and the stationkeeping ability of speed responsive ability, superelevation, thus servo is electric
The two-way gear oil pump that machine drives can outwards export the hydraulic oil stream of quick response, exact flow rate, two of two-way gear oil pump
Hydraulic fluid port is connected by oil pipe is one-to-one with two p ports of hydraulic lock respectively, one-to-one with two p ports in hydraulic lock
Two a ports pass through that oil pipe is one-to-one with the two chambers of oil cylinder to be connected respectively, also include hydraulic fluid chamber not with atmosphere
And it is provided that the buffer oil tank of the low-pressure hydraulic oil with pressure, two hydraulic fluid ports of two-way gear oil pump are connected a check valve respectively
It is connected with the hydraulic fluid port of buffer oil tank afterwards, the drain tap of two-way gear oil pump is connected with the hydraulic fluid port of buffer oil tank by oil pipe；
When servomotor drives two-way gear oil pump to start working, buffer oil tank can pass through the oil suction to two-way gear oil pump for the check valve
Mouth conveying low-pressure hydraulic oil, so that the oil-out of two-way gear oil pump can be able to make to that p port corresponding conveying in hydraulic lock
The high pressure liquid force feed that hydraulic lock is opened, after hydraulic lock is opened, high pressure liquid force feed flows into hydraulic lock from this p port, then from corresponding
A port flow out to the oil suction chamber of oil cylinder, thus driving cylinder movement, oil cylinder goes out hydraulic oil in oil pocket from another a port
Flow into hydraulic lock, then be circulated fuel feeding from the inlet port that another corresponding p port flows out to two-way gear oil pump, this
When, buffer oil tank no longer passes through check valve provides low-pressure hydraulic oil so that two-way gear oil to the inlet port of two-way gear oil pump
Hydraulic circuit between pump and oil cylinder becomes closed cycle loop.
Further, aforesaid gear pump control type electrohydraulic linkage actuating mechanism, wherein: the structure of buffer oil tank includes: case
Body, being provided with cabinets cavity can be along the piston of casing movement, and cabinets cavity is divided into two mutually disconnected chambeies by piston
Room, it may be assumed that shoe cream room and pushing tow chamber, offers the through hole being connected with shoe cream room on the box body wall of shoe cream room, and this through hole is
The hydraulic fluid port of buffer oil tank, is provided with the goring push spring of energy ejector piston in pushing tow chamber, can make storage after goring push spring ejector piston
Hydraulic oil in oil pocket becomes the low-pressure hydraulic oil with pressure.
Further, aforesaid gear pump control type electrohydraulic linkage actuating mechanism, wherein: the case in the pushing tow chamber relative with piston
Open-work is offered on body wall, open-work is equipped with a straight-bar, the inner of straight-bar is fixed with piston phase, thus straight-bar can be with
The movement of piston and stretch.
Further, aforesaid gear pump control type electrohydraulic linkage actuating mechanism, wherein: set outside the casing on straight-bar side
Put a scale parallel with straight-bar, scale has axially also been disposed adjacent repairing from inside to outside successively along scale and has indicated
Section, normal work indicating section, high oil temperature indicate section, flexible with straight-bar, and straight-bar outer end is projected in three sections on scale
Indicate and move in section, judge the situation of hydraulic oil in buffer oil tank by observing straight-bar outer end in the projected position on scale.
Further, aforesaid gear pump control type electrohydraulic linkage actuating mechanism, wherein: the hydraulic fluid port of buffer oil tank also leads to respectively
Cross two overflow valves to be connected with two hydraulic fluid ports of two-way gear oil pump, two overflow valves can adjust two-way gear oil pump respectively
The pressure of two oil ports.
Further, aforesaid gear pump control type electrohydraulic linkage actuating mechanism, wherein: buffer oil tank lower pressure hydraulic oil
Pressure is not higher than 1mpa.
Advantage of the present utility model is: gear pump control type electrohydraulic linkage actuating mechanism described in the utility model is by low energy consumption
Servomotor drive two-way gear oil pump output high pressure liquid to press oil to directly drive cylinder movement, it is to avoid using servo valve and liquid
Pressure station, on the premise of ensureing actuator response speed and positioning precision, enormously simplify the hydraulic circuit of actuator, with
When also reduce energy consumption；And the hydraulic circuit of this actuator not with atmosphere, so the hydraulic circuit of this actuator
In hydraulic oil be difficult by external environmental, substantially increase the reliability of actuator.
Brief description
Fig. 1 is the structural representation of gear pump control type electrohydraulic linkage actuating mechanism described in the utility model.
Fig. 2 is the structural representation of the buffer oil tank shown in Fig. 1.
Specific embodiment
With reference to specific embodiments and the drawings, this utility model is described in further detail.
As shown in figure 1, gear pump control type electrohydraulic linkage actuating mechanism, comprising: two-way gear oil pump 1, two-way gear oil pump 1
Driven by servomotor 2, so that two-way gear oil pump 1 can export the hydraulic oil stream of quick response, exact flow rate, bi-directional teeth
Two hydraulic fluid ports of wheel oil pump 1 are connected, with two in hydraulic lock 3 by oil pipe is one-to-one with two p ports of hydraulic lock 3 respectively
The one-to-one two a ports in p port are connected by oil pipe is one-to-one with the two chambers of oil cylinder 4 respectively, and hydraulic lock 3 is one
Plant the conventional hydraulic part with auto-lock function, when hydraulic lock 3 is closed, two groups of one-to-one p, a ports of difference in hydraulic lock
Between be all turned off and can not be interconnected, thus the hydraulic oil in the two chambers of oil cylinder 4 can be locked in two by hydraulic lock 3
So that oil cylinder 4 cannot action in chamber；Only to after a p port conveying high-pressure hydraulic oil of hydraulic lock 3, just can make hydraulic lock
3 open it may be assumed that make two groups respectively one-to-one p, a port be interconnected respectively, the oil suction chamber of such oil cylinder 4 could oil-feed, go out
Oil pocket could be fuel-displaced；Also include hydraulic fluid chamber and not with atmosphere and be provided that the buffer oil tank 5 of the low-pressure hydraulic oil with pressure,
In the present embodiment, as shown in Fig. 2 the structure of buffer oil tank 5 includes: casing 51, being provided with casing 51 inner chamber can be along
The piston 52 of casing 51 movement, piston 52 by casing 51 inner chamber be divided into two mutually disconnected chamber it may be assumed that shoe cream room 53 and pushing tow
Chamber 54, offers the through hole 55 being connected with shoe cream room 53 on the box body wall of shoe cream room 53, and this through hole 55 is buffer oil tank 5
Hydraulic fluid port, be provided with pushing tow chamber 54 can ejector piston 52 goring push spring 56, can make after goring push spring 56 ejector piston 52
Hydraulic oil in shoe cream room 53 becomes the low-pressure hydraulic oil with pressure, in the present embodiment, buffer oil tank 5 lower pressure hydraulic oil
Pressure is not higher than 1mpa；Two hydraulic fluid ports of two-way gear oil pump 1 are connected the hydraulic fluid port with buffer oil tank 5 after a check valve 6 respectively
It is connected, the drain tap of two-way gear oil pump 1 is connected with the hydraulic fluid port of buffer oil tank 5 by oil pipe；When servomotor 2 drive double
To gear oil pump 1 start working when, because now hydraulic lock 3 is closed, so the inlet port meeting of two-way gear oil pump 1
Because inhaling the oil less than hydraulic lock 3 output and reduced pressure, now buffer oil tank 5 can be by check valve 6 to two-way gear oil pump 1
Inlet port conveys low-pressure hydraulic oil, so that the oil-out of two-way gear oil pump 1 can be defeated to that p port corresponding in hydraulic lock 3
Send the high pressure liquid force feed that hydraulic lock 3 can be made to open, high pressure liquid force feed flows into hydraulic lock 3 from this p port after hydraulic lock 3 is opened,
Flow out to the oil suction chamber of oil cylinder 4 again from corresponding a port, thus driving oil cylinder 4 to move, the hydraulic pressure going out in oil pocket of oil cylinder 4
Oil flows into hydraulic lock 3 from another a port, then the inlet port flowing out to two-way gear oil pump 1 from another corresponding p port
In be circulated fuel feeding, now, the pressure going out the hydraulic oil flowing out oil pocket from oil cylinder 4 is higher than hydraulic oil in buffer oil tank 5
Pressure provides low-pressure hydraulic oil so that buffer oil tank 5 no longer passes through check valve 6 to the inlet port of two-way gear oil pump 1, now,
Hydraulic circuit between two-way gear oil pump 1 and oil cylinder 4 becomes closed cycle loop.When two-way gear oil pump 1 quits work,
Hydraulic lock 3 may turn off, and now the hydraulic oil in oil cylinder 4 two chambers will be locked in two chambers, thus oil cylinder 4 is not
Change in location can be produced because of load change.
In actual applications, deform upon because hydraulic oil itself is pressurized, the change of temperature in hydraulic circuit, two on oil cylinder
In the foozle of individual chamber, hydraulic circuit, the impact of the factor such as mechanically deform of each hydraulic unit is so that described in the utility model
The hydraulic circuit of actuator in hydraulic oil inevitably produce change in volume, thus easily cause two-way gear
Oil pump self-priming is smooth or the generation of oil circuit pocketed oil phenomenon, and oil circuit pocketed oil phenomenon refers to that unnecessary hydraulic oil is trapped in hydraulic circuit
Cannot discharge, above-mentioned two kinds of situations all can cause hydraulic circuit functional fault or damage, and the introducing of buffer oil tank 5 effectively solves
Determine the problems referred to above, when two-way gear oil pump suction is not smooth, buffer oil tank 5 can pass through check valve 6 to two-way gear oil pump
Inlet port provides the low-pressure hydraulic oil making its normal fuel injection；When there is oil circuit pocketed oil phenomenon, unnecessary hydraulic oil can be from two-way
The drain tap of gear oil pump is flowed in buffer oil tank.Further, since the hydraulic fluid chamber in buffer oil tank 5 not with atmosphere and
Being provided that low-pressure hydraulic oil, on the one hand making the hydraulic oil in actuator be not easily susceptible to the pollution of external environment, thus significantly carrying
The high reliability of actuator, on the other hand makes the work of hydraulic circuit be no longer dependent on atmospheric pressure, so that hydraulic circuit
It is no longer influenced by the impact of installation direction and height above sea level.
In the present embodiment, relative with piston 52 box body wall in pushing tow chamber 54 offers open-work 57, in open-work 57
It is equipped with a straight-bar 58, the inner of straight-bar 58 is mutually fixed with piston 52, thus straight-bar 58 can be stretched with moving of piston 52
Contracting, in a casing 51 piece scale 59 parallel with straight-bar 58 of outside setting on straight-bar 58 side, along scale 59 on scale 59
Axially also it has been disposed adjacent repairing from inside to outside successively and indicated section 591, normal work indicating section 592, high oil temperature sign section
593, flexible with straight-bar 58, three segment marks that are projected on scale 59 for straight-bar 58 outer end are shown and are moved in section, straight by observing
Bar 58 outer end to judge the situation of hydraulic oil in buffer oil tank 5 in the projected position on scale 59, when straight-bar 58 outer end is in scale
When projected position on 59 is located at repairing sign section 591, illustrate that in buffer oil tank 5, hydraulic oil is inadequate, workman is accomplished by buffering
Fuel tank 5 carries out repairing, when projected position on scale 59 for straight-bar 58 outer end is located at normal work indicating section 592, illustrates slow
Rush that fuel tank 5 is working properly, when projected position on scale 59 for straight-bar 58 outer end is located at high oil temperature and indicates section 593, explanation
The high oil temperature of hydraulic oil in buffer oil tank 5, leads to hydraulic oil excessively to expand, and now needs shutdown to safeguard.
In the present embodiment, the hydraulic fluid port of buffer oil tank 5 also passes through the two of two overflow valves 7 and two-way gear oil pump 1 respectively
Individual hydraulic fluid port is connected, and two overflow valves 7 can adjust the pressure of two oil ports of two-way gear oil pump 1 respectively, when two-way gear
When the pressure of two oil ports of oil pump 1 is more than the pressure that each overflow valve 7 sets, two overflow valves 7 can be respectively by two-way gear
The hydraulic oil overflow of two oil ports of oil pump 1 to buffer oil tank 5, thus limiting two hydraulic fluid ports of two-way gear oil pump 1
The maximum pressure at place, thus also define the EIAJ of actuator it is ensured that system safety.
Claims (6)
1. gear pump control type electrohydraulic linkage actuating mechanism, comprising: two-way gear oil pump it is characterised in that: two-way gear oil pump by
Servomotor drives, so that two-way gear oil pump can export the hydraulic oil stream of quick response, exact flow rate, two-way gear oil
Two hydraulic fluid ports of pump are connected, with two p ports one in hydraulic lock by oil pipe is one-to-one with two p ports of hydraulic lock respectively
One corresponding two a ports pass through that oil pipe is one-to-one with the two chambers of oil cylinder is connected respectively, also include hydraulic fluid chamber not with
Atmosphere and be provided that the buffer oil tank of the low-pressure hydraulic oil with pressure, two hydraulic fluid ports of two-way gear oil pump connect one respectively
It is connected with the hydraulic fluid port of buffer oil tank after individual check valve, the drain tap of two-way gear oil pump passes through the hydraulic fluid port of oil pipe and buffer oil tank
It is connected；When servomotor drives two-way gear oil pump to start working, buffer oil tank can be by check valve to two-way gear oil
The inlet port conveying low-pressure hydraulic oil of pump, so that the oil-out of two-way gear oil pump can be to that p port corresponding in hydraulic lock
Conveying can make the high pressure liquid force feed that hydraulic lock is opened, and after hydraulic lock is opened, high pressure liquid force feed flows into hydraulic lock from this p port, then
Flow out to the oil suction chamber of oil cylinder from corresponding a port, thus driving cylinder movement, oil cylinder goes out hydraulic oil in oil pocket from another
Individual a port flows into hydraulic lock, then is circulated from the inlet port that another corresponding p port flows out to two-way gear oil pump
Fuel feeding, now, buffer oil tank no longer passes through check valve provides low-pressure hydraulic oil so that two-way to the inlet port of two-way gear oil pump
Hydraulic circuit between gear oil pump and oil cylinder becomes closed cycle loop.
2. gear pump control type electrohydraulic linkage actuating mechanism according to claim 1 it is characterised in that: the structure of buffer oil tank
Including: casing, being provided with cabinets cavity can be along the piston of casing movement, and cabinets cavity is divided into two and does not mutually connect by piston
Logical chamber, it may be assumed that shoe cream room and pushing tow chamber, offers the through hole being connected with shoe cream room on the box body wall of shoe cream room, and this leads to
Hole is the hydraulic fluid port of buffer oil tank, is provided with the goring push spring of energy ejector piston, after goring push spring ejector piston in pushing tow chamber
The hydraulic oil in shoe cream room can be made to become the low-pressure hydraulic oil with pressure.
3. gear pump control type electrohydraulic linkage actuating mechanism according to claim 2 it is characterised in that: the top relative with piston
Push away and open-work is offered on the box body wall in chamber, open-work is equipped with a straight-bar, the inner of straight-bar is fixed with piston phase, thus directly
Bar can stretch with the movement of piston.
4. gear pump control type electrohydraulic linkage actuating mechanism according to claim 3 it is characterised in that: in the case on straight-bar side
External side arranges a scale parallel with straight-bar, has axially also been disposed adjacent benefit from inside to outside successively along scale on scale
Oil ga(u)ge shows that section, normal work indicating section, high oil temperature indicate section, flexible with straight-bar, projection on scale for the straight-bar outer end
Show in three segment marks and move in section, judge hydraulic oil in buffer oil tank in the projected position on scale by observing straight-bar outer end
Situation.
5. the gear pump control type electrohydraulic linkage actuating mechanism according to claim 1 or 2 or 3 or 4 it is characterised in that: buffering
The hydraulic fluid port of fuel tank is also connected with two hydraulic fluid ports of two-way gear oil pump by two overflow valves respectively, and two overflow valves can be distinguished
Adjust the pressure of two oil ports of two-way gear oil pump.
6. the gear pump control type electrohydraulic linkage actuating mechanism according to claim 1 or 2 or 3 or 4 it is characterised in that: buffering
The pressure of fuel tank lower pressure hydraulic oil is not higher than 1mpa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620670095.2U CN205918969U (en) | 2016-06-30 | 2016-06-30 | Gear pump control formula electro -hydraulic linkage actuating mechanism |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620670095.2U CN205918969U (en) | 2016-06-30 | 2016-06-30 | Gear pump control formula electro -hydraulic linkage actuating mechanism |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205918969U true CN205918969U (en) | 2017-02-01 |
Family
ID=57874430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620670095.2U Active CN205918969U (en) | 2016-06-30 | 2016-06-30 | Gear pump control formula electro -hydraulic linkage actuating mechanism |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205918969U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105952947A (en) * | 2016-06-30 | 2016-09-21 | 张家港市艾罗执行器有限公司 | Gear pump control type electrohydraulic linkage actuator |
| CN106812736A (en) * | 2017-03-21 | 2017-06-09 | 沈阳耐思控制技术有限公司 | The airtight positive pressure fuel tank of integrated electrical liquid execution system |
| CN111649018A (en) * | 2020-06-04 | 2020-09-11 | 南京理工大学 | Pump-controlled hydraulic cylinder integrated with external rotor motor |
-
2016
- 2016-06-30 CN CN201620670095.2U patent/CN205918969U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105952947A (en) * | 2016-06-30 | 2016-09-21 | 张家港市艾罗执行器有限公司 | Gear pump control type electrohydraulic linkage actuator |
| CN106812736A (en) * | 2017-03-21 | 2017-06-09 | 沈阳耐思控制技术有限公司 | The airtight positive pressure fuel tank of integrated electrical liquid execution system |
| CN111649018A (en) * | 2020-06-04 | 2020-09-11 | 南京理工大学 | Pump-controlled hydraulic cylinder integrated with external rotor motor |
| CN111649018B (en) * | 2020-06-04 | 2022-02-18 | 南京理工大学 | Pump-controlled hydraulic cylinder integrated with external rotor motor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100424361C (en) | Closed electrohydraulic controlling system | |
| CN105604991B (en) | A kind of submarine navigation device hatch door opens and closes hydraulic control system | |
| CN102588358B (en) | High-performance energy saving type electro-hydraulic servo control oil line | |
| CN105952946B (en) | Double dynamical gear pump control type electrohydraulic linkage executive control system | |
| CN104047912B (en) | The digital pump controlled hydraulic differential cylinder in self-powered source | |
| CN205918969U (en) | Gear pump control formula electro -hydraulic linkage actuating mechanism | |
| CN206035914U (en) | Four jar synchronous hydraulic system of automobile elevator | |
| CN202251171U (en) | Motion control device of cylinders in series | |
| CN104632794A (en) | Electro-hydraulic servo system of direct drive type hydraulic hoist | |
| CN102220863B (en) | Valve-controlled automatic confluence hydraulic system for horizontal directional drilling machine | |
| CN202055807U (en) | Hydraulic twin-well oil pumping unit utilizing back pressure of closed loop | |
| CN108252971A (en) | Hydroelectric power plant's double lifting point oil cylinder of hydraulic headstock gear travel synchronization automatic correction method | |
| CN111550458B (en) | Steam turbine pump cylinder control servo system and control method thereof | |
| CN105952699A (en) | Dual-power gear pump control type driving mechanism of electrohydraulic actuator | |
| CN203348203U (en) | Speed-regulating hydraulic control valve group of large-flow two-way cartridge valve | |
| CN105952947A (en) | Gear pump control type electrohydraulic linkage actuator | |
| CN205918968U (en) | Two power gear pump control formula electro -hydraulic linkage execution control systems | |
| CN205383139U (en) | Electricity liquid pump control cylinder with differential effect device | |
| CN105114392B (en) | A kind of oil cylinder, the closed Hydraulic system and control method using the oil cylinder | |
| CN201096115Y (en) | Hydraulic combined valve | |
| CN103133448B (en) | Energy-saving hydraulic valve with independently-controllable load throttle mouths and hydraulic valve control system | |
| CN206723172U (en) | Bender bidirectional pump liquid pressure control system | |
| CN205918668U (en) | Two power gear pump control formula actuating mechanism among electrohydraulic actuator | |
| CN100557231C (en) | Electrohydraulic synchronous cylinder type valve servo synchronous control system | |
| CN202090904U (en) | Automatic valve-controlled confluent hydraulic system of horizontal directional drilling machine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |