CN201363332Y - Large inertia variable frequency volume bypass throttling speed governing system - Google Patents

Large inertia variable frequency volume bypass throttling speed governing system Download PDF

Info

Publication number
CN201363332Y
CN201363332Y CNU2009200359589U CN200920035958U CN201363332Y CN 201363332 Y CN201363332 Y CN 201363332Y CN U2009200359589 U CNU2009200359589 U CN U2009200359589U CN 200920035958 U CN200920035958 U CN 200920035958U CN 201363332 Y CN201363332 Y CN 201363332Y
Authority
CN
China
Prior art keywords
valve
way
oil
circuit
pump
Prior art date
Application number
CNU2009200359589U
Other languages
Chinese (zh)
Inventor
赵继云
赵亮
李炳文
丁海港
Original Assignee
中国矿业大学
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 中国矿业大学 filed Critical 中国矿业大学
Priority to CNU2009200359589U priority Critical patent/CN201363332Y/en
Application granted granted Critical
Publication of CN201363332Y publication Critical patent/CN201363332Y/en

Links

Abstract

A large inertia variable frequency volume bypass throttling speed governing system is suitable for a hydraulic hoisting machine with relatively high requirements on large inertia, high power and startup and shutdown speed control, which comprises a hydraulic volume speed governing circuit, a bypass throttling speed governing circuit, an oil recharging heat interchange circuit and a shock resistance braking circuit. The bypass throttling speed governing is adopted to achieve a relatively good low speed control performance when the system starts and operates at low speed, after the speed reaches a certain degree, the variable frequency volume speed governing is adopted, the frequency converter controls the rotational speed of the frequency conversion motor, then by governing the output flow quantity of the two-way hydraulic pump and driving the hydraulic motor to control the running speed and direction of the loading, so as to achieve the required speed control regularity and the energy saving effect. The oil recharging heat interchange circuit is used in the closed type system to recharge oil and complete the heat interchange. The shock resistance braking circuit is used to release the peak pressure in the main circuit when the driving large inertia loading motor brakes or stops, so as to protect the two-way pump and the hydraulic motor.

Description

Big inertia frequency conversion volume by-pass throttle speed control system

Technical field

The utility model relates to a kind of speed control system, and especially a kind of frequency conversion volume by-pass throttle speed control system of big inertia load is applicable to as big inertia such as hydraulic hoisting machine, high-power, occasion that the start and stop speed controlling is had relatively high expectations.

Background technique

For this big inertia of similar hydraulic hoisting machine, large-power hydraulic system, it is started acceleration performance, braking ability and efficient all the higher requirement of ratio.There are very big restriction loss in motion speed and direction that traditional throttle grverning system utilizes throttle valve to come control load, this kind mode of speed regulation, so energy consumption is big, efficient is low, are not suitable for high-power big inertia system.Adopt the Frequency Converter Control variable-frequency motor to drive the frequency conversion volumetric speed control of metering pump, can come the output flow of regulator solution press pump according to the need of work of load, no spill losses and restriction loss, system has higher efficient, has the energy conservation characteristic that general variance pump-control-motor speed control system with adjustable displacement is not had in high-power system.But the high-power metering pump in the frequency conversion speed control system with adjustable displacement all has a minimum regime flow, and is lower in executive component speed, and required flow is during less than the minimum regime flow of oil hydraulic pump, because oil hydraulic pump output flow and pressure instability, thereby the speed controlling poor-performing.Simultaneously for big inertia, high-power hydraulic system, oil hydraulic motor easily takes place to rotate slowly under big inertia load or action of gravity, can produce potential safety hazard, thereby need reliably brake, the anti-again simultaneously locking system phenomenon that caused pressure raises suddenly when braking it.

Summary of the invention

The purpose of this utility model provides a kind of system simple at the problem that prior art exists, and low speed control is reliable, and the throttle grverning response is fast, transmission efficiency height, the big inertia frequency conversion volume by-pass throttle speed control system of saving the energy.

The technical scheme in the invention for solving the technical problem is: it comprises variable-frequency motor, the bidirectional hydraulic pump that links to each other with variable-frequency motor, the bidirectional hydraulic pump links to each other through the two-way hydraulic motor of high low pressure oil circuit with the head roll rotation, be connected with the master cylinder of brake drum on the two-way hydraulic motor, be parallel with the 2/2-way pilot operated directional control valve of two pairs of opposite one-way valve groups of oil circuit direction, 3-position-3-way pilot operated directional control valve and serial connection throttle valve on the high low pressure oil circuit that bidirectional hydraulic pump and two-way hydraulic motor link to each other successively; Be connected with the repairing heat exchange loop on a pair of one-way valve group in the left side, the right company is connected with the safety valve that forms safety protection loop on a pair of one-way valve group, and is connected with the electrohydraulic proportional velocity regulating valve of the formation by-pass throttle flow control circuit that outlet and fuel tank communicate; The control oil channel of 2/2-way pilot operated directional control valve and the oil circuit of master cylinder are provided with the protecting against shock brake circuit; The duplex oil hydraulic pump links to each other by two one-way valves of the filter and the one-way valve group left side, is connected with the relief valve that forms the repairing heat exchange loop on the 3-position-3-way pilot operated directional control valve.

Described repairing heat exchange loop comprises the high-capacity pump in the duplex oil hydraulic pump left side that links to each other with motor, be connected with the relief valve of control oil-supplementing system maximum pressure between high-capacity pump and the one-way valve group oil circuit, high-capacity pump filler opening place is connected with oil purifier, and the oil outlet place is connected with fine filter; Described protecting against shock brake circuit comprises the low-capacity pump on duplex pump right side, and low-capacity pump connects the two-bit triplet solenoid directional control valve of control brake cylinder break-make, is provided with relief valve between low-capacity pump and the two-bit triplet solenoid directional control valve; Be provided with throttle valve between described two-bit triplet solenoid directional control valve and the master cylinder; The low-capacity pump filler opening on described duplex pump right side is connected with filter, and oil outlet is connected with fine filter.

Beneficial effect:

1) flow control circuit is the form that the frequency conversion volumetric speed control combines with electric-hydraulic proportion bypass speed adjusting technique.Because oil hydraulic pump has minimum stable engine speed, when the rotational speed regulation of pump was lower than its minimum stable engine speed, oil hydraulic pump output flow and pressure instability were so the frequency conversion volumetric speed control must could obtain good speed adjusting performance on the minimum stabilized (steady-state) speed of pump.Thereby when low speed start, adopt electrohydraulic proportional velocity regulating valve bypass mode of speed regulation, to realize the effect of low speed control preferably, because the throttle grverning response is fast, improved the low speed speed adjusting performance of oil hydraulic motor simultaneously; After the rotating speed of pump reaches certain value, automatically switch to frequency conversion volumetric speed control mode by control system, thereby this hydraulic speed regulation system has the transmission efficiency height simultaneously, saves characteristics such as the energy, more obvious for the high-power system energy-saving effect.Because major loop adopts closed system, by the Frequency Converter Control variable-frequency motor, the fluid that changes the bidirectional hydraulic pump is exported the sense of rotation that oily direction can change oil hydraulic motor, does not need selector valve and commutation loop can realize commutation, and system is simple.

2) for big inertia system if brake into and out of hydraulic fluid port by the locking oil hydraulic motor separately because the leakage of system, motor can slowly trackslip under the effect of big inertia-gravity load, is difficult to realize braking reliably, thereby is provided with brake circuit in the system.When the motor that drives big inertia load stops or braking; usually can produce high surge pressure in the major loop; though be provided with safety valve in the system; but its response is slower; damage two-way variable displacement pump and oil hydraulic motor in order to prevent too high pressure peak; be connected on the major loop high and low pressure oil circuit with a throttle valve and pilot operated directional control valve, when braking, connect major loop high and low pressure side, to discharge the peak value high pressure in the major loop by throttle valve.

3) be applicable to big inertia, occasion high-power and that start and stop section low-speed performance is had relatively high expectations, as hydraulic hoisting machine.Realization is to the reliable braking of big inertia load.

Description of drawings

Accompanying drawing is a hydraulic schematic diagram of the present utility model.

Among the figure: the 1-frequency variator; The 2-variable-frequency motor; The 3-coupling; 4-bidirectional hydraulic pump; 5-one-way valve group; 6-3-position-3-way pilot operated directional control valve; The 7-throttle valve; 8-2/2-way pilot operated directional control valve; The 9-master cylinder; The 10-two-way hydraulic motor; The 11-cylinder; The 12-throttle valve; 13-two-bit triplet solenoid directional control valve; The 14-relief valve; The 15-electrohydraulic proportional velocity regulating valve; The 16-safety valve; The 17-relief valve; The 18-motor; The 19-duplex pump; 20,22-coarse-grain filtering device; 21,23-fine filter; The 24-relief valve; The 25-fuel tank; The 26-PLC controller.

Embodiment

As shown in drawings, big inertia frequency conversion volume by-pass throttle speed control system of the present utility model, mainly by flow control circuit, safety protection, repairing heat exchange loop and protecting against shock brake circuit four parts constitute, and control with PLC controller 26.Wherein: flow control circuit comprises frequency variator 1, frequency variator 1 control variable-frequency motor 2 drives bidirectional hydraulic pump 4 through coupling 3, bidirectional hydraulic pump 4 drives two-way hydraulic motor 10, two-way hydraulic motor 10 drives cylinder 11 rotations, electrohydraulic proportional velocity regulating valve 15 is connected between one-way valve group 5 and the fuel tank 25, forms the by-pass throttle flow control circuit.Two one-way valve oil outlets on one-way valve group 5 the right link to each other with safety valve 16, the Maximum operating pressure of main oil hydraulic circuit is set up by safety valve 16, thereby make the pressure in 10 liang of chambeies of two-way hydraulic motor be no more than peak, reduced the use amount of safety valve simultaneously, simplified hydraulic system.Safety protection, repairing and heat exchange loop comprise motor 18; motor 18 drives duplex oil hydraulic pump 19; the high-capacity pump in duplex oil hydraulic pump 19 left sides through oil purifier 20 from fuel tank 25 oil suctions; oil outlet is connected with fine filter 21; oil circuit one tunnel is through relief valve 24 oil sump tanks, another road through one-way valve group 5 to the major loop repairing.6 two hydraulic fluid ports of pilot operated directional control valve are connected on respectively on the high and low pressure oil circuit of major loop, and another hydraulic fluid port takes back fuel tank through relief valve 14.Safety valve 16 is connected between one-way valve group 5 and the fuel tank 25.The annexation of each components and parts is as follows in the protecting against shock brake circuit: the little pump in the right side in the duplex pump 19 through filter 22 from fuel tank 25 oil suctions; little pump discharge connects fine filter 23; the one tunnel takes back fuel tank through relief valve 17; the one tunnel connects two-bit triplet solenoid directional control valve 13; two-bit triplet solenoid directional control valve 13 two hydraulic fluid ports one tunnel in addition directly takes back fuel tank; the one tunnel is connected to the hydraulic fluid port of master cylinder 9 through throttle valve 12; throttle valve 7 and 8 series connections of 2/2-way pilot operated directional control valve are at the major loop height; on the low pressure road, and the hydraulic control hydraulic fluid port of 2/2-way pilot operated directional control valve 8 is connected on the oil circuit between master cylinder 9 and the throttle valve 12.

System works principle: when system during at low speed start, frequency variator 1 output control signal works bidirectional hydraulic pump 4 by variable-frequency motor 2, coupling 3 under its minimum stable engine speed, oil hydraulic pump 4 outputs one minimum regime flow, removed by the fluid of oil hydraulic pump 4 output and to enter 10 rotations of two-way hydraulic motor drive motor, the one tunnel through one-way valve group 5, electrohydraulic proportional velocity regulating valve 15 by-pass oil sump tanks in addition.The aperture of electrohydraulic proportional velocity regulating valve 15 is by 26 controls of PLC controller.During startup, the aperture of electrohydraulic proportional velocity regulating valve 15 is transferred to maximum, the fluid of bidirectional hydraulic pump 4 outputs is all through one-way valve group 5, electrohydraulic proportional velocity regulating valve 15 oil sump tanks, thereby motor rotary speed is zero, the aperture of electrohydraulic proportional velocity regulating valve 15 requires to reduce gradually according to the control of system start-up speed then, flow by electrohydraulic proportional velocity regulating valve 15 reduces gradually, the flow that then enters oil hydraulic motor 10 is increasing, motor speed increases gradually, and its accelerating process is controlled by electrohydraulic proportional velocity regulating valve 15 fully.After electrohydraulic proportional velocity regulating valve 15 was closed fully, system's speed governing automatically switched to the frequency conversion volumetric speed control by PLC controller 26.After this, the flow of two-way variable displacement pump 4 outputs all enters oil hydraulic motor 10, the rule running that the rotating speed of motor is set according to frequency variator fully.Thereby realize the compound control that variable frequency hydraulic volumetric speed control and the speed governing of series flow control valve by-pass throttle combine.Owing to be provided with electrohydraulic proportional velocity regulating valve 15, increased the draining passage of system, the impact in the time of can effectively avoiding system start-up because the throttle grverning response is fast, has improved the low speed speed adjusting performance of oil hydraulic motor simultaneously.During system shutdown, as the low cruise speed when stopping higher control requirement is arranged, adopt frequency conversion volumetric speed control mode to allow motor 10 slow down earlier, after reducing to a certain degree, the rotating speed of oil hydraulic pump 4 no longer reduces, but increase the aperture of electrohydraulic proportional velocity regulating valve 15 as requested gradually by PLC controller 26, flow by electrohydraulic proportional velocity regulating valve 15 increases gradually, and the output flow of oil hydraulic pump 4 is constant, to reduce gradually so enter the flow of two-way hydraulic motor 10, motor speed reduces until parking.

Claims (5)

1. one kind big inertia frequency conversion volume by-pass throttle speed control system, it is characterized in that: it comprises variable-frequency motor (2), the bidirectional hydraulic pump (4) that links to each other with variable-frequency motor (2), bidirectional hydraulic pump (4) links to each other through the two-way hydraulic motor (10) of high low pressure oil circuit with head roll (11) rotation, be connected with the master cylinder (9) of brake drum (11) on the two-way hydraulic motor (10), be parallel with the opposite two pairs of one-way valve groups (5) of oil circuit direction successively on the high low pressure oil circuit that bidirectional hydraulic pump (4) and two-way hydraulic motor (10) link to each other, the 2/2-way pilot operated directional control valve (8) of 3-position-3-way pilot operated directional control valve (6) and serial connection throttle valve (7); Be connected with the repairing heat exchange loop on a pair of one-way valve group in the left side (5), be connected with the safety valve (16) that forms safety protection loop on the right a pair of one-way valve group (5), and be connected with the electrohydraulic proportional velocity regulating valve (15) of the formation by-pass throttle flow control circuit that outlet and fuel tank (25) communicate; The oil circuit of the control oil channel of 2/2-way pilot operated directional control valve (8) and master cylinder (9) is provided with the protecting against shock brake circuit; Duplex oil hydraulic pump (19) links to each other by two one-way valves of the filter (21) and one-way valve group (5) left side, is connected with the relief valve (14) that forms the repairing heat exchange loop on the 3-position-3-way pilot operated directional control valve (6).
2. big inertia frequency conversion volume by-pass throttle speed control system according to claim 1, it is characterized in that: described repairing heat exchange loop comprises the high-capacity pump in duplex oil hydraulic pump (19) left side that links to each other with motor (18), be connected with the relief valve (24) of control oil-supplementing system maximum pressure between high-capacity pump and one-way valve group (5) oil circuit, high-capacity pump filler opening place is connected with oil purifier (20), and the oil outlet place is connected with fine filter (21).
3. big inertia frequency conversion volume by-pass throttle speed control system according to claim 1, it is characterized in that: described protecting against shock brake circuit comprises the low-capacity pump on duplex pump (19) right side, low-capacity pump connects the two-bit triplet solenoid directional control valve (13) of control brake cylinder (9) break-make, is provided with relief valve (17) between low-capacity pump and the two-bit triplet solenoid directional control valve (13).
4. big inertia frequency conversion volume by-pass throttle speed control system according to claim 3 is characterized in that: be provided with throttle valve (12) between described two-bit triplet solenoid directional control valve (13) and the master cylinder (9).
5. big inertia frequency conversion volume by-pass throttle speed control system according to claim 3, it is characterized in that: the low-capacity pump filler opening on described duplex pump (19) right side is connected with filter (22), and oil outlet is connected with fine filter (23).
CNU2009200359589U 2009-03-05 2009-03-05 Large inertia variable frequency volume bypass throttling speed governing system CN201363332Y (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNU2009200359589U CN201363332Y (en) 2009-03-05 2009-03-05 Large inertia variable frequency volume bypass throttling speed governing system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNU2009200359589U CN201363332Y (en) 2009-03-05 2009-03-05 Large inertia variable frequency volume bypass throttling speed governing system

Publications (1)

Publication Number Publication Date
CN201363332Y true CN201363332Y (en) 2009-12-16

Family

ID=41473995

Family Applications (1)

Application Number Title Priority Date Filing Date
CNU2009200359589U CN201363332Y (en) 2009-03-05 2009-03-05 Large inertia variable frequency volume bypass throttling speed governing system

Country Status (1)

Country Link
CN (1) CN201363332Y (en)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102384120A (en) * 2011-10-24 2012-03-21 江苏谷登工程机械装备有限公司 Volume speed-regulation hydraulic system of unit head of core drill
CN103466047A (en) * 2013-09-02 2013-12-25 中国船舶重工集团公司第七一〇研究所 Reciprocating buoyancy regulating unit for autonomous profile buoy platform
CN103758805A (en) * 2013-12-27 2014-04-30 北京市三一重机有限公司 Main pushing hydraulic system and tube push bench
CN104595290A (en) * 2014-12-30 2015-05-06 浙江大学台州研究院 Hydraulic inerter with initiative and controllable inert coefficient
CN103352889B (en) * 2013-07-08 2015-07-01 太原理工大学 Method for buffering hydraulic system shock of crawler loader
CN105422094A (en) * 2015-11-16 2016-03-23 中国矿业大学 Direct-drive hydraulic transmission coal mining machine cutting rotary drum height regulating system and method
CN105483869A (en) * 2016-01-26 2016-04-13 湖州南浔中兴丝织有限公司 Silk winding unit of silk winding and strip forming production device
CN105483871A (en) * 2016-01-26 2016-04-13 湖州南浔中兴丝织有限公司 Hot press unit of silk winding and strip forming production device
CN105483870A (en) * 2016-01-26 2016-04-13 湖州南浔中兴丝织有限公司 Silk winding mechanical part of silk winding and strip forming production device
CN105525395A (en) * 2016-01-26 2016-04-27 湖州南浔中兴丝织有限公司 Hot pressing mechanism of linen silk winding and strip forming device
CN105525394A (en) * 2016-01-26 2016-04-27 湖州南浔中兴丝织有限公司 Winding mechanism of linen silk winding and strip forming device
CN105545839A (en) * 2016-01-29 2016-05-04 贵阳海之力液压有限公司 Oil cylinder reversing and volume speed adjusting hydraulic system
CN105696121A (en) * 2016-01-26 2016-06-22 湖州南浔中兴丝织有限公司 Production device for coiling silks into strips
CN106523453A (en) * 2016-12-22 2017-03-22 天津好记科技发展有限公司 Electromechanical actuator having cavity prevention function
CN106762992A (en) * 2016-12-22 2017-05-31 天津好记科技发展有限公司 Electromechanical actuator with pressure holding function
CN108397447A (en) * 2017-12-27 2018-08-14 中国矿业大学 A kind of valve-pump joint multi-mode hydraulic control system and its control method
CN108547809A (en) * 2018-06-07 2018-09-18 北汽福田汽车股份有限公司 Control system and trucd mixer with it
CN110030304A (en) * 2019-04-22 2019-07-19 太原理工大学 A kind of coordinated drive and passive active brake method of large inertia load
CN110307193A (en) * 2019-07-09 2019-10-08 中国矿业大学 A kind of large-capacity valve-pump jointly controls emulsion power pack and its control method
CN110469551A (en) * 2019-08-26 2019-11-19 北京航天发射技术研究所 A kind of filling hydraulic system based on ratio bypass speed regulating control

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102384120A (en) * 2011-10-24 2012-03-21 江苏谷登工程机械装备有限公司 Volume speed-regulation hydraulic system of unit head of core drill
CN103352889B (en) * 2013-07-08 2015-07-01 太原理工大学 Method for buffering hydraulic system shock of crawler loader
CN103466047A (en) * 2013-09-02 2013-12-25 中国船舶重工集团公司第七一〇研究所 Reciprocating buoyancy regulating unit for autonomous profile buoy platform
CN103466047B (en) * 2013-09-02 2015-10-21 中国船舶重工集团公司第七一〇研究所 The reciprocating buoyancy regulating device of a kind of self-sustaining profile buoy platform
CN103758805A (en) * 2013-12-27 2014-04-30 北京市三一重机有限公司 Main pushing hydraulic system and tube push bench
CN103758805B (en) * 2013-12-27 2016-03-23 北京市三一重机有限公司 Main propulsion hydraulic system and push-bench
CN104595290A (en) * 2014-12-30 2015-05-06 浙江大学台州研究院 Hydraulic inerter with initiative and controllable inert coefficient
CN105422094A (en) * 2015-11-16 2016-03-23 中国矿业大学 Direct-drive hydraulic transmission coal mining machine cutting rotary drum height regulating system and method
CN105422094B (en) * 2015-11-16 2017-12-19 中国矿业大学 A kind of direct drive type hydraulic transmission coal-winning machine cutting drum height-adjusting system and method
CN105483871B (en) * 2016-01-26 2017-11-24 湖州南浔中兴丝织有限公司 Silk is around the heat-pressure unit for being rolled into bar process units
CN105483870A (en) * 2016-01-26 2016-04-13 湖州南浔中兴丝织有限公司 Silk winding mechanical part of silk winding and strip forming production device
CN105525395A (en) * 2016-01-26 2016-04-27 湖州南浔中兴丝织有限公司 Hot pressing mechanism of linen silk winding and strip forming device
CN105525394A (en) * 2016-01-26 2016-04-27 湖州南浔中兴丝织有限公司 Winding mechanism of linen silk winding and strip forming device
CN105483871A (en) * 2016-01-26 2016-04-13 湖州南浔中兴丝织有限公司 Hot press unit of silk winding and strip forming production device
CN105696121A (en) * 2016-01-26 2016-06-22 湖州南浔中兴丝织有限公司 Production device for coiling silks into strips
CN105483869A (en) * 2016-01-26 2016-04-13 湖州南浔中兴丝织有限公司 Silk winding unit of silk winding and strip forming production device
CN105525394B (en) * 2016-01-26 2017-12-01 湖州南浔中兴丝织有限公司 Silk is around the coiling mechanism for being rolled into strip device
CN105525395B (en) * 2016-01-26 2017-11-24 湖州南浔中兴丝织有限公司 Flax filament winding is rolled into the hot pressing mechanism of strip device
CN105545839A (en) * 2016-01-29 2016-05-04 贵阳海之力液压有限公司 Oil cylinder reversing and volume speed adjusting hydraulic system
CN106762992A (en) * 2016-12-22 2017-05-31 天津好记科技发展有限公司 Electromechanical actuator with pressure holding function
CN106523453A (en) * 2016-12-22 2017-03-22 天津好记科技发展有限公司 Electromechanical actuator having cavity prevention function
CN108397447A (en) * 2017-12-27 2018-08-14 中国矿业大学 A kind of valve-pump joint multi-mode hydraulic control system and its control method
CN108397447B (en) * 2017-12-27 2019-10-15 中国矿业大学 A kind of valve-pump joint multi-mode hydraulic control system and its control method
CN108547809A (en) * 2018-06-07 2018-09-18 北汽福田汽车股份有限公司 Control system and trucd mixer with it
CN110030304A (en) * 2019-04-22 2019-07-19 太原理工大学 A kind of coordinated drive and passive active brake method of large inertia load
CN110307193A (en) * 2019-07-09 2019-10-08 中国矿业大学 A kind of large-capacity valve-pump jointly controls emulsion power pack and its control method
CN110469551A (en) * 2019-08-26 2019-11-19 北京航天发射技术研究所 A kind of filling hydraulic system based on ratio bypass speed regulating control

Similar Documents

Publication Publication Date Title
EP2797766B1 (en) Driving system and electric vehicle comprising the same
CN102241379B (en) Energy-saving travelling type hydraulic transport machine
CN1206147C (en) Hydraulic lift energy-saving control system with hydraulic transformer
CN100427771C (en) Energy saving hydraulic lifting system of variable hydraulic counterweight
CN102168754B (en) Hydraulic control system for wet-type double-clutch automatic transmission
CN103148031B (en) Energy-saving control system of hydraulic movable arm loop
CN100532864C (en) Hydraulic control
JP3679749B2 (en) Hydraulic device
CN103267034B (en) Load sensitive hydraulic system with compensation valve energy recovery function
CN102336370B (en) Rotating hydraulic system of crane and control method thereof
CN101723271B (en) Hydraulic control system for crane hoisting
CN1256521C (en) Frequency converter volume variable speed closed hydraulic control systems
CN100520087C (en) Rotating speed variable driving shield cutterhead energy-saving hydraulic control system
CN101734565B (en) Crane and winch control system thereof
US7509806B2 (en) Method for optimizing the utilization ratio in a drive unit and drive unit
CN201771496U (en) Hydraulic tracting system for shearer driven by load sensitive pump
CN1239970C (en) Electro-hydraulic control system and method based on frequency-conversion speed regulation
DE112009000708B4 (en) Controller for hybrid construction equipment
CN202266536U (en) Hydraulic control valve and engineering machinery running system
CN104163385B (en) A kind of winch hydraulic control system
CN201321358Y (en) Crane hoist control system and crane
CN100424361C (en) Closed electrohydraulic controlling system
CN201851432U (en) Hydraulic system
KR0166131B1 (en) Oil pressure circuit for lift car
CN101907165A (en) The hydraulic supply unit of automatic transmission

Legal Events

Date Code Title Description
GR01 Patent grant
C14 Grant of patent or utility model
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20091216

Termination date: 20100305

C17 Cessation of patent right