CN203717499U - Closed type hydraulic transmission system - Google Patents

Abstract

The utility model discloses a closed type hydraulic transmission system and overcomes the defects of impact pressure of high-pressure oil on a motor shell during state switching and resistance to running of a vehicle caused by the pressure in a loop when a hydraulic motor does not work. The closed type hydraulic transmission system comprises a power input mechanism, a hydraulic pump assembly, a hydraulic control valve group, a first hydraulic motor, a second hydraulic motor, a non-pressurization oil tank and a control unit, wherein the power input mechanism is mechanically connected with the hydraulic pump assembly; the hydraulic pump assembly is in pipeline connection with the hydraulic control valve group; the hydraulic control valve group is in pipeline connection with the first hydraulic motor and the second hydraulic motor respectively and simultaneously; the first hydraulic motor is mechanically connected with a loaded mass body of the first hydraulic motor; the second hydraulic motor is mechanically connected with a loaded mass body of the second hydraulic motor; the hydraulic pump assembly and the hydraulic control valve group are in pipeline connection with the non-pressurization oil tank simultaneously; the control unit is connected with the hydraulic pump assembly and the hydraulic control valve group simultaneously through signal lines.

Description

A kind of Closed circuit hydraulic transmission system

Technical field

The utility model relates to a kind of transmission system being applied on heavy truck or heavy engineering haulage vehicle, and or rather, the utility model relates to a kind of Closed circuit hydraulic transmission system.

Background technique

At present, the working condition more complicated of the vehicles such as heavy truck or engineering vehicle is changeable, often can travel low adhering on road surface at muddy, sandstone or ice and snow etc., or in the time climbing long slope, occur that driving wheel skids, not foot phenomenon of driving force.Solution to this problem mainly contains full wheel drive structure, the auxiliary front-wheel drive structure of electric wheel and the auxiliary front-wheel drive structure of hydraulic pressure.Entirely drive structure and be widely used in cross-country passenger car field, but the mechanical transmission structure of itself is complicated and increase larger quality, and be not suitable for the engineering transportation vehicle such as heavy truck or tractor; Rapidly and increase less quality, repacking is convenient for the latest developments of electric wheel actuation techniques, but the application of problem the limited electric wheel technology such as the little life-span of power of current battery is short and electric machine controller cost costliness, control technique be immature; Hydraulic Power Transmission System has simple in structure, specific power is large, repacking cost is low, the features such as technical development maturation, generally, for engineering vehicle field, radial piston hydraulic motor volume is little simultaneously, can be arranged in the wheel hub of front-wheel, when not taking up space, also there is low-speed big feature, be generally applied in the drive system of engineering vehicle.

The scholars such as the external U.S., Japan have just proposed the auxiliary f-w-d vehicle of hydraulic system that adopts oil hydraulic pump and oil hydraulic motor to form, wheel system before the companies such as European BOSCH-REXROTH, ripple Crane, MAN release one after another and assist for the hydraulic pressure of engineering vehicle in the seventies.Domestic for hydraulicdriven research, focus mostly in the past in engineering machinery field, present stage also starts to pay close attention to gradually the development of hydraulic transmission in commercial car field, such as hydraulic hybrid technology etc.For hydraulic hybrid technical elements, now existing a lot of patents or document are open; Chinese patent notification number is CN1423581611, and the day for announcing is 2012.05.16, discloses a kind of hub hydraulic motor driving system, adopts oil hydraulic pump and oil hydraulic motor to form the technology of the auxiliary front-wheel drive of method of closed circuit.

As can be seen here, the present stage hydraulic transmission technology research that is applied to the fields such as heavy type transport vehicle receives more concern.Hydraulic drive circuit mainly comprises open type and closed-type cylindrical gearing loop, and hydraulic hybrid power system adopts open circuit more, and the drive system of engineering machinery adopts closed circuit more.The fast feature of the large reaction velocity of pressure high flow capacity of considering closed circuit, adopts closed circuit for the auxiliary front-wheel drive system of heavy truck or heavy engineering car more.But this front-wheel assistant drive system, need to change different working staties, and high pressure oil causes larger surge pressure to the housing of motor in the time that state switches.In addition, in the time that oil hydraulic motor is not worked, in hydraulic drive circuit, there is certain pressure, can, to the generation drag effect of travelling of vehicle, increase the oil consumption of motor, affect the operating life of oil hydraulic motor simultaneously.At target vehicles such as heavy trucks, in the time shifting gears or the short time, urgent parking operated, hydraulic system should be able to quit work rapidly, after operation completes, can start fast again, in order to avoid increase gearshift resistance, disturbs driver to shift gears or promptly parking.

Summary of the invention

Technical problem to be solved in the utility model is that while having overcome the switching of prior art existence, high pressure oil causes larger surge pressure with in the time that oil hydraulic motor is not worked to the housing of motor, in hydraulic drive circuit, there is certain pressure, the problem that can produce to travelling of vehicle drag effect, provides a kind of Closed circuit hydraulic transmission system.

For solving the problems of the technologies described above, the utility model is to adopt following technological scheme to realize: described a kind of Closed circuit hydraulic transmission system includes load quality body, second oil hydraulic motor of power input mechanism, hydraulic pump module, hydraulic control valve group, the first oil hydraulic motor, the first oil hydraulic motor, load quality body, oil tank and the control unit of the second oil hydraulic motor.

Between power input mechanism and hydraulic pump module for mechanical type is connected, between hydraulic pump module and hydraulic control valve group for pipeline is connected, between hydraulic control valve group and the first oil hydraulic motor for pipeline is connected, between hydraulic control valve group and the second oil hydraulic motor for pipeline is connected, hydraulic control valve group is with being connected with the second hydraulic motor lines with the first oil hydraulic motor, between the load quality body of the first oil hydraulic motor and the first oil hydraulic motor for mechanical type is connected, between the load quality body of the second oil hydraulic motor and the second oil hydraulic motor for mechanical type is connected, hydraulic pump module and hydraulic control valve group with and oil tank pipeline be connected, control unit is with being connected with hydraulic control valve group signaling line with hydraulic pump module.

Between hydraulic pump module described in technological scheme and hydraulic control valve group, for being connected, pipeline refers to: the port PA of hydraulic pump module is connected with the port VA pipeline of hydraulic control valve group, the port PC of hydraulic pump module is connected with the port VC pipeline of hydraulic control valve group, and the port PB of hydraulic pump module is connected with the port VB pipeline of hydraulic control valve group.

Between hydraulic control valve group described in technological scheme and the first oil hydraulic motor, refer to for pipeline is connected: the port MA1 of hydraulic control valve group is connected with master port 151 pipelines of the first oil hydraulic motor, the port MB1 of hydraulic control valve group is connected with master port 152 pipelines of the first oil hydraulic motor.

Between hydraulic control valve group described in technological scheme and the second oil hydraulic motor, refer to for pipeline is connected: the port MB2 of hydraulic control valve group is connected with master port 182 pipelines of the second oil hydraulic motor, the port MA2 of hydraulic control valve group is connected with master port 181 pipelines of the second oil hydraulic motor.

Hydraulic control valve group described in technological scheme is with being connected and referring to the second hydraulic motor lines with the first oil hydraulic motor: the port MC of hydraulic control valve group is with being connected with the housing earial drainage port one 53 of the first oil hydraulic motor and housing earial drainage port one 83 pipelines of the second oil hydraulic motor.

Between the first oil hydraulic motor described in technological scheme and the load quality body of the first oil hydraulic motor for mechanical type is connected, between the load quality body of the second oil hydraulic motor and the second oil hydraulic motor, for being connected, mechanical type refers to: the turning axle of the load quality body of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor are the i.e. load transmission shaft of the first oil hydraulic motor of the same axis, or the turning axle of load quality body (17) of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor are not the same axis but the load transmission shaft of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor, adopt spline pair to connect between the two,

The turning axle of the load quality body of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor are the i.e. load transmission shaft of the second oil hydraulic motor of the same axis, or the turning axle of the load quality body of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor are not the same axis but the load transmission shaft of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor, adopt spline pair to connect between the two.

Hydraulic pump module described in technological scheme includes power input shaft, oil hydraulic pump, slippage pump, the first relief valve, the second relief valve, the 3rd relief valve, the first one-way valve, the second one-way valve, first direction valve, second direction valve, oil hydraulic cylinder and displacement transducer X.The input shaft of power input shaft and oil hydraulic pump, the rotor shaft of slippage pump are the same axis, and the port 41 of oil hydraulic pump adopts the port PA of pipeline L1 and hydraulic pump module, the oil outlet of the first one-way valve to be connected with the filler opening of the second relief valve; The port 42 of oil hydraulic pump adopts the port PB of pipeline L2 and hydraulic pump module, the oil outlet of the second one-way valve to be connected with the filler opening of the 3rd relief valve; The swash plate of oil hydraulic pump is connected with one end ball pivot of the piston in oil hydraulic cylinder.

The oil outlet of slippage pump adopts port PC, the filler opening of the first relief valve, the filler opening of the first one-way valve, the filler opening of the second one-way valve, the oil outlet of the second relief valve, the oil outlet of the 3rd relief valve, the port P of first direction valve, the port P of second direction valve of pipeline L3 and hydraulic pump module to be connected, and the filler opening of slippage pump adopts pipeline L2 to be connected with oil tank.

The port A of first direction valve adopts pipeline to be connected with the port one 32 of oil hydraulic cylinder, the port A of second direction valve adopts pipeline to be connected with the port one 31 of oil hydraulic cylinder, the port T of first direction valve is connected with oil tank by pipeline with the port T of second direction valve, and displacement transducer X is arranged on one end of the piston in oil hydraulic cylinder.

Hydraulic control valve group described in technological scheme comprises the one-way valve of flushing valve, the 4th relief valve, third direction valve, fourth direction valve, the 5th directional control valve, the 6th directional control valve and demarcation.The port A of flushing valve is connected with the port VA of hydraulic control valve group, the port P of fourth direction valve by pipeline L4, the port B of flushing valve is connected with the port VB of hydraulic control valve group, the port T of fourth direction valve by pipeline L5, and the port T of flushing valve is connected with the filler opening of the 4th relief valve by pipeline.The port P of third direction valve is connected with the port VC of hydraulic control valve group by pipeline; The port T of third direction valve is connected with the port T1 of hydraulic control valve group by pipeline; The port A of third direction valve is connected with oil circuit control port K2 with the oil circuit control port K1 of fourth direction valve by pipeline successively with port B.The port P of fourth direction valve is connected with the port VA of hydraulic control valve group by pipeline L4; The port T of fourth direction valve is connected with the port VB of hydraulic control valve group by pipeline L5; The port A of fourth direction valve is connected with the port P of the 5th directional control valve by pipeline; The port B of fourth direction valve is connected with the port T of the 6th directional control valve by pipeline.The port T of the 5th directional control valve is connected by pipeline L9 and the port P of the 6th directional control valve, the port T2 of hydraulic control valve group, and the port A of the 5th directional control valve is connected with the port MA1 of hydraulic control valve group, the port MA2 of hydraulic control valve group by oil circuit L6; The port B of the 5th directional control valve is connected with the port B of the 6th directional control valve, the port MC of hydraulic control valve group by pipeline L8.The port A of the 6th directional control valve is connected with the port MB1 of hydraulic control valve group, the port MB2 of hydraulic control valve group by pipeline L7, and the one-way valve of demarcation is arranged on and connects between the 5th directional control valve and the pipeline L8 and pipeline L9 of the 6th directional control valve.

Compared with prior art the beneficial effects of the utility model are:

1. a kind of Closed circuit hydraulic transmission system transmission of pressure described in the utility model is high, reaction velocity is fast;

In a kind of Closed circuit hydraulic transmission system described in the utility model hydraulic pump module integrated main pump and regulate servo-control mechanism, oil-supplementing system and the structure of relief valve of its discharge capacity, oil hydraulic motor adopts radial plunger type motor, and be integrated in the wheel hub of front-wheel, whole system physical dimension is little, take up room little, arrange with installation simple and convenient;

3. the hydraulic control valve group in the hydraulic drive circuit of a kind of Closed circuit hydraulic transmission system described in the utility model, can meet oil hydraulic motor and switch under different conditions, meets the operations such as driver's gearshift or interim parking simultaneously, has good adaptability for working condition;

4. a kind of Closed circuit hydraulic transmission system described in the utility model is when oil hydraulic motor is during in freewheel state, hydraulic control valve group can make the certain pressure of reservation in motor casing, make that motor plunger and motor casing are thorough to be separated, eliminated the additional load to front-wheel when motor is not worked;

5. a kind of Closed circuit hydraulic transmission system described in the utility model is in the time that oil hydraulic motor is in running order, and control valve group can be laid down the pressure of motor casing fast, and while having reduced motor operations, the additional load of housing pressure to motor, has reduced complete-vehicle oil consumption;

6. a kind of Closed circuit hydraulic transmission system described in the utility model is in the time that the vehicle short time shifts gears, hydraulic control valve group control oil hydraulic motor is by bypass, gearshift finishes rear rapid recovery drive condition, the pressure that has reduced like this oil hydraulic motor short time motor working connection when switching state changes, reduce the compression shock of motor casing, improved the operating life of oil hydraulic motor.

Brief description of the drawings

Below in conjunction with accompanying drawing, the utility model is further described:

Fig. 1 is the structure principle chart of a kind of Closed circuit hydraulic transmission system described in the utility model;

Fig. 2 is the structural drawing of hydraulic control valve group in a kind of Closed circuit hydraulic transmission system described in the utility model;

In figure: 1. power input device, 2. pto＝power take-off, 3. hydraulic pump module, 4. oil hydraulic pump, 5. slippage pump, 6. the first relief valve, 7. the first one-way valve, 8. the second one-way valve, 9. the second relief valve, 10. the 3rd relief valve, 11. first direction valves, 12. second direction valves, 13. oil hydraulic cylinders, 14. hydraulic control valve groups, 15. first oil hydraulic motors, the load transmission shaft of 16. first oil hydraulic motors, the load quality body of 17. first oil hydraulic motors, 18. second oil hydraulic motors, the load transmission shaft of 19. second oil hydraulic motors, the load quality body of 20. second oil hydraulic motors, 21. oil tanks, 22. control units, 43. swash plates, 44. power input shafts, 133. piston, 141. flushing valve, 142. the 4th relief valves, 143. third direction valves, 144. fourth direction valves, 145. the 5th directional control valves, 146. the 6th directional control valves, 147. one-way valves of demarcating.

Embodiment

Below in conjunction with accompanying drawing, the utility model is explained in detail:

The purpose of this utility model is to provide a kind of Closed circuit hydraulic transmission system, described a kind of Closed circuit hydraulic transmission system is mainly used in the auxiliary front-wheel drive structure of the target vehicle such as heavy truck or heavy engineering haulage vehicle, improves driving force and the passing ability of vehicle in the time that driving wheel skids;

Hydraulic control valve group in described a kind of Closed circuit hydraulic transmission system can regulator solution pressure motor different conditions, the compression shock of motor casing while reducing state switching, meet the requirement of driver's gearshift or the operation of parking in short-term simultaneously, eliminate the additional load to motor when system works, when reducing the oil consumption of car load, improve the operating life of oil hydraulic motor.

Consult Fig. 1, a kind of Closed circuit hydraulic transmission system provided by the utility model includes load transmission shaft 16, the load quality body 17 of the first oil hydraulic motor, the second oil hydraulic motor 18, the load transmission shaft 19 of the second oil hydraulic motor, the load quality body 20 of the second oil hydraulic motor, the oil tank 21 and control unit 22 of power input device 1, pto＝power take-off 2, hydraulic pump module 3, hydraulic control valve group 14, the first oil hydraulic motor 15, the first oil hydraulic motor.

Power input device 1 and pto＝power take-off 2 form the power input mechanism of hydraulic pump module 3, and power input device 1, for inputing to the device of hydraulic pump module 3 power, can be power take-off or other power transmission mechanisms;

Pto＝power take-off 2 is the output shaft of power input device 1, pto＝power take-off 2 adopts mechanical type to be connected with the power input shaft 44 of hydraulic pump module 3, Placement can be common key or spline pair or by connecting with flange plate after universal joint, power input device 1 and pto＝power take-off 2 make power source can be stably by transmission of power to hydraulic pump module 3, make hydraulic pump module 3 provide pressure oil for Closed circuit hydraulic transmission system; In this example, can be regarded as motor and provide power by power input device 1 and pto＝power take-off 2 to hydraulic pump module 3, make the normal work output of hydraulic pump module 3 high-voltage oil liquid.

Hydraulic pump module 3 includes power input shaft 44, oil hydraulic pump 4, slippage pump 5, the first relief valve 6, the second relief valve 9, the 3rd relief valve 10, the first one-way valve 7, the second one-way valve 8, first direction valve 11, second direction valve 12, oil hydraulic cylinder 13 and for measuring the displacement transducer X of oil hydraulic cylinder 13 piston 133 displacements.

Power input shaft 44 is the same axis with the input shaft of oil hydraulic pump 4, the rotor shaft of slippage pump 5, and power input shaft 44 adopts foregoing mechanical type Placement to be connected with pto＝power take-off 2; Power source (for example motor) passes to hydraulic pump module 3 power by power input device 1 and pto＝power take-off 2, drives oil hydraulic pump 4 and slippage pump 5 working pump oil through power input shaft 44;

Oil hydraulic pump 4 is beidirectional plunger type high-pressure variable displacement pumps, works with the load that overcomes the first oil hydraulic motor 15 and the second oil hydraulic motor 18 for a kind of Closed circuit hydraulic transmission system provides high-voltage drive fluid.

The port 41 of oil hydraulic pump 4 adopts the port PA of pipeline L1 and hydraulic pump module 3, the oil outlet of the first one-way valve 7 to be jointly connected with the filler opening of the second relief valve 9; The port 42 of oil hydraulic pump 4 adopts the port PB of pipeline L2 and hydraulic pump module 3, the oil outlet of the second one-way valve 8 to be jointly connected with the filler opening of the 3rd relief valve 10; The swash plate 43 of oil hydraulic pump 4 is that ball pivot is connected with one end of the piston 133 in oil hydraulic cylinder 13, to meet the proportional relationship change of displacement of piston 133 in the swashplate angle of oil hydraulic pump 4 and oil hydraulic cylinder 13.

Oil hydraulic pump 4 is beidirectional oil hydraulic pump, the port 41 of oil hydraulic pump 4 and the port 42 of oil hydraulic pump 4 be all filler opening be also oil outlet; When oil hydraulic pump 4 is during from port 42 oil-feed, 41 of the ports of oil hydraulic pump 4 are fuel-displaced, are set as oil hydraulic pump 4 forwards, and now in oil hydraulic pump 4, the change of pitch angle scope of swash plate 43 is 0～+ 1; When oil hydraulic pump 4 is during from port 41 oil-feed, 42 of the ports of oil hydraulic pump 4 are fuel-displaced, are set as oil hydraulic pump 4 and reverse, and now in oil hydraulic pump 4, the change of pitch angle scope of swash plate 43 is-1～0.

Slippage pump 5 is metering pumps of single effect, for system low-voltage transmission loop supplements transmission fluid.The oil outlet of slippage pump 5 adopts port PC, the filler opening of the first relief valve 6, the filler opening of the first one-way valve 7, the filler opening of the second one-way valve 8, the oil outlet of the second relief valve 9, the oil outlet of the 3rd relief valve 10, the port P of first direction valve 11, the port P(of second direction valve 12 of pipeline L3 and hydraulic pump module 3 will be described later) be connected, the filler opening of slippage pump 5 adopts pipeline to be connected with oil tank 21, when work, from oil tank 21, extracts fluid.

The first relief valve 6 is arranged on pipeline L3 and oil tank 21(is oil outlet and the oil tank 21 of slippage pump 5) between, to limit the oil outlet that pipeline L3(is slippage pump 5) pressure, realize protection slippage pump 5 objects.The first relief valve 6 is set lower numerical value, and this numerical value is called first threshold.The first threshold maximum pressure that to be slippage pump 5 allow to pipeline L1 or pipeline L2 repairing, is also the maximum pressure that pipeline L3 allows, and in the present embodiment, first threshold is set as 30bar.

The first one-way valve 7 is arranged between pipeline L1 and pipeline L3, can only allow fluid to flow to pipeline L1.The second one-way valve 8 is arranged between pipeline L2 and pipeline L3, can only allow fluid to flow to pipeline L2.

Slippage pump 5, the first relief valve 6, the first one-way valve 7 and the common feed circuit that forms described Closed circuit hydraulic transmission system of the second one-way valve 8; In the time of oil hydraulic pump 4 forward, slippage pump 5 is carried the pressurization fluid of the pressure limit that is subject to the first relief valve 6 to pipeline L2 by pipeline L3, the second one-way valve 8; In the time that oil hydraulic pump 4 reverses, slippage pump 5 is carried the pressurization fluid of the pressure limit that is subject to the first relief valve 6 to pipeline L1 by pipeline L3, the first one-way valve 7.

The second relief valve 9 and the 3rd relief valve 10 be all as safety valve, and similar with the first one-way valve 7 and the second one-way valve 8, is separately positioned between pipeline L1 and pipeline L3, pipeline L2 and pipeline L3, to limit the pressure of pipeline L1 and pipeline L2;

The second relief valve 9 and the 3rd relief valve 10 are set to identical high value, and this numerical value is called Second Threshold.Second Threshold is hydraulic control valve group 14, oil hydraulic pump 4, the first oil hydraulic motor 15 and 18 maximum pressures that can allow of the second oil hydraulic motor.In the present embodiment, Second Threshold is set as 420bar, and in the time that the pressure difference of pipeline L1 and pipeline L3 exceedes 420bar, the second relief valve 9 makes pipeline L1 and pipeline L3 connect and keep the working pressure of 420bar in pipeline L1; The working pressure of pipeline L2 is also the same.

First direction valve 11 and second direction valve 12 are all three-position three-way valves.The port P of first direction valve 11, adopts pipeline L3 to be jointly connected to the oil outlet of slippage pump 5 with the port P of second direction valve 12; The port A of first direction valve 11 adopts pipeline to be connected to the port one 32 of oil hydraulic cylinder 13; The port A of second direction valve 12, is connected to the port one 31 of oil hydraulic cylinder 13 by pipeline; The port T of first direction valve 11 and the port T of second direction valve 12 are connected to oil tank 21 jointly by pipeline.

First direction valve 11 is two valves that structure is identical with second direction valve 12, therefore the following first direction valve 11 of only describing in detail.

First direction valve 11 is in the time of primary importance I, and port P is cut off, and slippage pump 5 can not pass through the outside fuel feeding of first direction valve 11, and the port A of first direction valve 11 is communicated with the port T of first direction valve 11; First direction valve 11 is in the time of second place II, and the port T of the port P of first direction valve 11, the port A of first direction valve 11 and first direction valve 11 is all cut off, and slippage pump 5 can not pass through the outside fuel feeding of first direction valve 11; First direction valve 11 is in the time of the 3rd position III, and the port P of first direction valve 11 is communicated with the port A of first direction valve 11, and slippage pump 5 is by the outside fuel feeding of first direction valve 11, and the port T of first direction valve 11 is cut off.

First direction valve 11 is to belong to solenoid directional control valve, the direct manipulation of double-action electromagnet, a pair of spring reset; Respectively there are an electromagnet and a Returnning spring in the two ends of first direction valve 11, and the input end of the electromagnetic coil in two electromagnet is connected with control unit 22 by signaling line respectively; When original state, spool is positioned in the second place, and after electromagnetic coil (being the upper end electromagnet of first direction valve 11 in Fig. 2) energising of the first electromagnet of first direction valve 11, the spool of first direction valve 11 is switched to primary importance under the effect of electromagnetic force; When after electromagnetic coil (being the lower end electromagnet of first direction valve 11 in Fig. 2) energising of the secondth electromagnet of first direction valve 11, the spool of first direction valve 11 is switched to the 3rd position under the effect of electromagnetic force; After electromagnetic coil power-off, spool turns back to the second place under the effect of Returnning spring.

Piston 133 in oil hydraulic cylinder 13 is double piston-rod structure, can way moving, and oil hydraulic cylinder 13 original states mediate.

The port one 31 of oil hydraulic cylinder 13 is connected to the port A of second direction valve 12 by pipeline; The port one 32 of oil hydraulic cylinder 13 is connected to the port A of first direction valve 11 by pipeline; The method that one end (being shown as upper end in accompanying drawing 1) of the close oil hydraulic pump 4 of piston 133 adopts ball pivot to connect is connected to the swash plate 43 of oil hydraulic pump 4; When in oil hydraulic cylinder 13, piston 133 moves, the proportional variation thereupon of the inclination angle of the swash plate 43 of oil hydraulic pump 4; The other end away from oil hydraulic pump 4 (being shown as lower end in accompanying drawing 1) of piston 133 is provided with displacement transducer X, and displacement transducer X is connected to control unit 22 by signaling line; Displacement transducer X is for the displacement of measuring oil hydraulic cylinder 13 pistons 133, and by this displacement (, the inclination angle of swash plate 43 in oil hydraulic pump 4) feedback transmission to control unit 22.

First direction valve 11 and second direction valve 12, the common controlling mechanism that forms swash plate 43 inclination angles in oil hydraulic pump 4 of oil hydraulic cylinder 13; In the time that first direction valve 11 is placed in position I and second direction valve 12 and is placed in position III, oil hydraulic cylinder 13 is from port one 31 oil-feeds, port one 32 oil extractions of oil hydraulic cylinder 13, and piston 133 moves up, thereby drives the inclination angle of swash plate 43 in oil hydraulic pump 4 to change to+1 direction; In the time that first direction valve 11 is placed in position III and second direction valve 12 and is placed in position I, oil hydraulic cylinder 13 is from port one 32 oil-feeds, port one 31 oil extractions of oil hydraulic cylinder 13, piston 133 moves down, thereby drives the inclination angle of the swash plate 43 in oil hydraulic pump 4 to change to-1 direction.

Consult Fig. 1, the port VA of hydraulic control valve group 14 is connected to the port PA of hydraulic pump module 3 by hydraulic pipe line; The port VB of hydraulic control valve group 14 is connected to the port PB of hydraulic pump module 3 by hydraulic pipe line; The port VC of hydraulic control valve group 14 is connected to the port PC of hydraulic pump module 3 by hydraulic pipe line;

The port MA1 of hydraulic control valve group 14 and the port MA2 of hydraulic control valve group 14 are connected respectively to the master port 151 of the first oil hydraulic motor 15 and the master port 181 of the second oil hydraulic motor 18 by hydraulic pipe line; The port MB1 of hydraulic control valve group 14 and the port MB2 of hydraulic control valve group 14, be connected respectively to the master port 152 of the first oil hydraulic motor 15 and the master port 182 of the second oil hydraulic motor 18 by hydraulic pipe line; The port MC of hydraulic control valve group 14 is connected with the housing earial drainage port one 53 of the first oil hydraulic motor 15 and the housing earial drainage port one 83 of the second oil hydraulic motor 18 by hydraulic pipe line; The port T1 of hydraulic control valve group 14 and the port T2 of hydraulic control valve group 14 are connected to oil tank 21 by hydraulic pipe line.

The first oil hydraulic motor 15 is two oil hydraulic motors that structure is identical with the second oil hydraulic motor 18, only describes the first oil hydraulic motor 15 here in detail.

The first oil hydraulic motor 15 is radial plunger type two-way quantitative motors, adopts spline pair to be connected or both are for the same axis between its rotor shaft and the load transmission shaft 16 of the first oil hydraulic motor; The master port 151 of the first oil hydraulic motor 15 and the master port 152 of the first oil hydraulic motor 15 are connected to the port MA1 of hydraulic control valve group 14 and the port MB1 of hydraulic control valve group 14 by hydraulic pipe line respectively, and the housing earial drainage port one 53 of the first oil hydraulic motor 15 is connected to the port MC of hydraulic control valve group 14 by hydraulic pipe line.Pressure oil liquid can flow into and flow out from the master port 152 of the first oil hydraulic motor 15 from the master port of the first oil hydraulic motor 15 151, is now called the first oil hydraulic motor 15 forwards; Also can flow into and flow out from the master port 151 of the first oil hydraulic motor 15 from the master port of the first oil hydraulic motor 15 152, now be called the first oil hydraulic motor 15 and reverse.

The modular construction that the load transmission shaft 16 of the first oil hydraulic motor and the load quality body of the first oil hydraulic motor 17, the load transmission shaft 19 of the second oil hydraulic motor and the load quality body 20 of the second oil hydraulic motor form is identical with function, only describes the assembly that the load transmission shaft 16 of the first oil hydraulic motor and the load quality body 17 of the first oil hydraulic motor form here in detail.

The load transmission shaft 16 of the first oil hydraulic motor and the load quality body 17 of the first oil hydraulic motor form the support structures of the first oil hydraulic motor 15, the turning axle of the load quality body 17 of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor 15 are the i.e. load transmission shaft 16 of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor 15 of the same axis, or not the same axis but the load transmission shaft 16 of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor 15 adopt spline pair form mechanical connection between the two; The load quality body 17 of the first oil hydraulic motor is the load quality body of the rotatable motion of the first oil hydraulic motor 15, the load quality body 17 of the first oil hydraulic motor is sleeved on one end of the load transmission shaft 16 of the first oil hydraulic motor with one heart, and can rotate together with the load transmission shaft 16 of the first oil hydraulic motor.

The turning axle of the load quality body 20 of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor 18 are the i.e. load transmission shaft 19 of the second oil hydraulic motor of the same axis, or the turning axle of the load quality body 20 of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor 18 are not the same axis but the load transmission shaft 19 of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor 18, adopt spline pair to connect between the two; The load quality body 20 of the second oil hydraulic motor is set with one end of the load transmission shaft 19 that is fixed on the second oil hydraulic motor with one heart, and can rotate together with the load transmission shaft 19 of the second oil hydraulic motor.

The load quality body 17 of the first oil hydraulic motor and the load quality body 20 of the second oil hydraulic motor are installed in the front-wheel inside of target vehicle (not shown), in the time that these mass bodies rotate with the load transmission shaft 16 of the first oil hydraulic motor and the load transmission shaft 19 of the second oil hydraulic motor, can drive front-wheel to rotate; Further can think the semiaxis that the load transmission shaft 16 of the first oil hydraulic motor is front-wheel, the load quality body 17 of the first oil hydraulic motor is the rotating mass body of semiaxis in front-wheel, and first rotor shaft of oil hydraulic motor 15 and the semiaxis of front-wheel adopt spline pair to be connected, and first housing of oil hydraulic motor 15 and the front-wheel hub of target vehicle adopt mechanical bolt to be connected (scheming not shown).

Consult Fig. 2, hydraulic control valve group 14 comprises flushing valve 141, the 4th relief valve 142, third direction valve 143, fourth direction valve 144, the 5th directional control valve 145, the 6th directional control valve 146 and the one-way valve 147 of demarcating.

The 4th relief valve 142 and the common cooling circuit that forms fluid in hydraulic drive circuit of flushing valve 141;

Flushing valve 141 is arranged between pipeline L4 and pipeline L5, and the port A of flushing valve 141 is connected with the port VA of hydraulic control valve group 14, the port P of fourth direction valve 144 by pipeline L4; The port B of flushing valve 141 is connected with the port VB of hydraulic control valve group 14, the port T of fourth direction valve 144 by pipeline L5; The port T of flushing valve 141 is connected with the filler opening of the 4th relief valve 142 by pipeline.

Flushing valve 141 has primary importance I, second place II and the 3rd position III, and flushing valve 141 is in the time of primary importance I, and the port A of flushing valve 141 is connected with the port T of flushing valve 141, and the port B of flushing valve 141 is cut off; Flushing valve 141 is in the time of second place II, and the port T of the port A of flushing valve 141, the port B of flushing valve 141 and flushing valve 141 is all cut off; Flushing valve 141 is in the time of the 3rd position III, and the port B of flushing valve 141 is connected with the port T of flushing valve 141, and the port A of flushing valve 141 is cut off.

Flushing valve 141 is hydraulicchange-over valves, and its spool is that it is axially movable by the pressure difference control of port A and port B, and in the time that the pressure of port A is greater than the pressure of port B, flushing valve 141 becomes primary importance from the second place; In the time that the pressure of port A is less than the pressure of port B, flushing valve 141 becomes the 3rd position from the second place; In the time that the pressure of port A equates with the pressure of port B, turn back to the second place by two relative Returnning springs.

The 4th relief valve 142 is arranged on the oil circuit between flushing valve 141 and the port T1 of hydraulic control valve group 14, makes the port T1 of hydraulic control valve group 14 keep certain pressure; The first threshold that the setting pressure of the 4th relief valve 142 is set lower than said system.In the present embodiment, the setting pressure of the 4th relief valve 142 is set as 80% of above-mentioned first threshold.

Third direction valve 143 is two-position four-way valves.The port P of third direction valve 143 is connected to the port VC of hydraulic control valve group 14 by pipeline; The port T of third direction valve 143 is connected to the port T1 of hydraulic control valve group 14 by pipeline; Oil circuit control port K1 and oil circuit control port K2(that the port A of third direction valve 143 and port B are connected to fourth direction valve 144 by pipeline respectively will be described later).

Third direction valve 143 has primary importance I and second place II, third direction valve 143 is in the time of primary importance I, the port P of third direction valve 143 is cut off, and the port T of the port A of third direction valve 143, the port B of third direction valve 143 and third direction valve 143 communicates; Third direction valve 143 is in the time of second place II, and the port P of third direction valve 143 is communicated with the port A of third direction valve 143, and the port T of third direction valve 143 is communicated with the port B of third direction valve 143.

Third direction valve 143 is solenoid directional control valves, and single-acting electromagnet is handled, spring reset, and the input end of the electromagnetic coil in its electromagnet is connected to control unit 22 by signaling line; After electromagnetic coil energising, the spool of third direction valve 143 is switched to the second place from primary importance under the effect of electromagnetic force, and after electromagnetic coil power-off, the spool of third direction valve 143 is got back to primary importance under action of reset spring.

Fourth direction valve 144 is two-position four-way valves.The port P of fourth direction valve 144 is connected to the port VA of hydraulic control valve group 14 by pipeline L4; The port T of fourth direction valve 144 is connected to the port VB of hydraulic control valve group 14 by pipeline L5; The port A of fourth direction valve 144 is connected to the port P of the 5th directional control valve 145 by pipeline; The port B of fourth direction valve 144, is connected to the port T of the 6th directional control valve 146 by pipeline.

Fourth direction valve 144 has primary importance I and second place II, fourth direction valve 144 is in the time of primary importance I, the port P of fourth direction valve 144 is communicated with the port A of fourth direction valve 144, and the port T of fourth direction valve 144 is communicated with the port B of fourth direction valve 144; Fourth direction valve 144 is in the time of second place II, and the port P of fourth direction valve 144 and the port T of fourth direction valve 144 are cut off, and the port A of fourth direction valve 144 is communicated with the port B of fourth direction valve 144.

Fourth direction valve 144 is hydraulic control valves, fourth direction valve 144 is switched to second place II from primary importance I, the movement direction of the spool of fourth direction valve 144 is to be determined by the port K1 of oil circuit control and the pressure difference of port K2, and turns back to primary importance I by the Returnning spring at two ends; And the port K1 of its oil circuit control is connected with port B by the port A of pipeline and third direction valve 143 respectively with port K2.

Third direction valve 143 is by electromagnetic force regulating spool position, and then the port K1 of change fourth direction valve 144 and the pressure of port K2, when third direction valve 143 is during in second place II, the port K1 of fourth direction valve 144 is connected to the port P of third direction valve 143 by oil circuit, and be connected to the output pipe L3 of slippage pump 5 by the port VC of oil circuit and hydraulic control valve 14, and port K2 is connected to the port T of third direction valve 143 by oil circuit, and be connected to oil tank 21 and off-load by the port T1 of oil circuit and hydraulic control valve group 14, cause the pressure of the port K1 of fourth direction valve 144 to be greater than the pressure of the port K2 of fourth direction valve 144, the spool of fourth direction valve 144 is moved, make fourth direction valve 144 be switched to second place II from primary importance I, in the time that third direction valve 143 is placed in primary importance I, the port K1 of fourth direction valve 144 and port K2 mutually connect by third direction valve 143 and are connected to oil tank 21 and off-load turns back to primary importance under the effect of the spool of fourth direction valve 144 by the Returnning spring at two ends by the port T1 of oil circuit and hydraulic control valve group 14.

The 5th directional control valve 145 and the 6th directional control valve 146 are two-position four-way valve.The port P of the 5th directional control valve 145 is connected to the port A of fourth direction valve 144 by pipeline; The port T of the 5th directional control valve 145 is connected with the port P of the 6th directional control valve 146, the port T2 of hydraulic control valve group 14 by pipeline L9 simultaneously; The port A of the 5th directional control valve 145 is connected with the port MA1 of hydraulic control valve group 14, the port MA2 of hydraulic control valve group 14 by oil circuit L6 simultaneously.The port B of the 5th directional control valve 145 is connected with the port B of the 6th directional control valve 146, the port MC of hydraulic control valve group 14 by pipeline L8 simultaneously.

The port T of the 6th directional control valve 146 is connected to the port B of fourth direction valve 144 by pipeline; The port A of the 6th directional control valve 146 is connected with the port MB1 of hydraulic control valve group 14, the port MB2 of hydraulic control valve group 14 by oil circuit L7 simultaneously;

The 5th directional control valve 145 has primary importance I and second place II, the 5th directional control valve 145 is in the time of primary importance I, the port P of the 5th directional control valve 145 is communicated with the 5th directional control valve 145 port B, and the port T of the 5th directional control valve 145 is communicated with the port A of the 5th directional control valve 145; The 5th directional control valve 145 is in second place II, and the port P of the 5th directional control valve 145 is communicated with the port A of the 5th directional control valve 145, and the port T of the 5th directional control valve 145 is communicated with the port B of the 5th directional control valve 145;

The 5th directional control valve 145 is solenoid directional control valves, and single-acting electromagnet is handled, spring reset, and the electromagnetic coil input end in its electromagnet is connected to control unit 22 by signaling line; The 5th directional control valve 145 is switched to the second place from primary importance, and the spool of the 5th directional control valve 145 is mobile under the effect of electromagnetic force, and turns back to primary importance by Returnning spring.

The 6th directional control valve 146 has primary importance I and second place II, the 6th directional control valve 146 is in the time of primary importance I, the port P of the 6th directional control valve 146 is communicated with the 6th directional control valve 146 port A, and the port T of the 6th directional control valve 146 is communicated with the port B of the 6th directional control valve 146; The 6th directional control valve 146 is in second place II, and the port P of the 6th directional control valve 146 is communicated with the port B of the 6th directional control valve 146, and the port T of the 6th directional control valve 146 is communicated with the port A of the 6th directional control valve 146;

The 6th directional control valve 146 is solenoid directional control valves, and single-acting electromagnet is handled, spring reset, and the electromagnetic coil input end in its electromagnet is connected to control unit 22 by signaling line; The 6th directional control valve 146 is switched to the second place from primary importance, and the spool of the 6th directional control valve 146 is mobile under the effect of electromagnetic force, and turns back to primary importance by Returnning spring.

The one-way valve 147 of demarcating is arranged on and connects between the 5th directional control valve 145 and the pipeline L8 and pipeline L9 of the 6th directional control valve 146, and allow fluid only can exceed demarcated pressure at the pressure of oil circuit L8, flow towards oil circuit L9, the force value of demarcating is called the 3rd threshold value, and this threshold value is the maximum pressure that oil circuit L8 allows.In the present embodiment, the 3rd Threshold is 3ar to 5bar.

The port A of the port MA1 of hydraulic control valve group 14, the port MA2 of hydraulic control valve group 14 and the 5th directional control valve 145 forms three-way pipe structure by oil circuit L6, and namely the port MA1 of hydraulic control valve group 14 and the port MA2 of hydraulic control valve group 14 are relations in parallel; Same, the port MB1 of hydraulic control valve group 14 is also relation in parallel with the port MB2 of hydraulic control valve group 14; And the port one 51 of the first oil hydraulic motor 15 and the port one 52 of the first oil hydraulic motor 15 are connected respectively to the port MA1 of hydraulic control valve group 14 and the port MB1 of hydraulic control valve group 14, the port one 81 of the second oil hydraulic motor 18 and the port one 82 of the second oil hydraulic motor 18 are connected respectively to the port MA2 of hydraulic control valve group 14 and the MB2 of hydraulic control valve group 14, therefore, the first oil hydraulic motor 15 and the second oil hydraulic motor 18 arrange with parallel form.For convenience of description, below, only describe the port MA1 of hydraulic control valve group 14 and the port MB1 of hydraulic control valve group 14 and the first oil hydraulic motor 15 in detail.

Hydraulic control valve group 14 is connected between hydraulic pump module 3 and the first oil hydraulic motor 15, to control the working state of the first oil hydraulic motor 15.Spool in hydraulic control valve group 14 in fourth direction valve 144, the 5th directional control valve 145 and the 6th directional control valve 146, in the time of diverse location, can make hydraulic control valve group 14 connect different ports, as shown in the table;

By connecting different ports, hydraulic control valve group 14 can be controlled the first oil hydraulic motor 15 and be operated in arbitrary mode of operation in following three kinds of patterns:

Freewheel pattern:

Under this pattern, the first oil hydraulic motor 15 is not worked, not outputting power, and the housing earial drainage port one 53 of the first oil hydraulic motor 15 retains certain pressure, separates with motor casing is thorough with the radial plunger that ensures oil hydraulic motor;

Drive pattern:

Under this pattern, oil hydraulic pump 4 and the first oil hydraulic motor 15 form closed hydraulic loop, the first oil hydraulic motor 15 outputting power of working, the simultaneously direct earial drainage of housing earial drainage port one 53 of the first oil hydraulic motor 15;

Bypass mode:

Under this pattern, oil hydraulic pump 4 is cut off, and the first oil hydraulic motor 15 is by bypass, not outputting power, and the master port 151 of the first oil hydraulic motor 15 and master port 152 remain with certain pressure, the direct earial drainage of its housing earial drainage port one 53.

To the operation of the disclosed system of the utility model be described now.This operation is controlled by control unit 22.The input end of the electromagnetic coil in system in the electromagnet of first direction valve 11, second direction valve 12, third direction valve 143, the 5th directional control valve 145 and the 6th directional control valve 146 is all connected to control unit 22 by signaling line, and controlled by control unit 22, the displacement transducer X in oil hydraulic cylinder 13 on piston 133 is connected to control unit 22.

In order not make accompanying drawing content too complicated, the displacement transducer X on the piston 133 of above-mentioned different directional control valve and oil hydraulic cylinder 13 is not connected and does not illustrate in the drawings with the signaling line of control unit 22.

The function of control unit 22 has two, and the one, by controlling first direction valve 11 and the second direction valve 12 in hydraulic pump module 3, the swashplate angle of regulator solution press pump 4, and then the discharge capacity of regulator solution press pump 4; The 2nd, by controlling third direction valve 143, the 5th directional control valve 145 and the 6th directional control valve 146 in hydraulic control valve group 14, regulate the working state of the first oil hydraulic motor 15.

The displacement signal of piston displacement sensor X feedback in control unit 22 receiving liquid cylinder pressures 13, and this displacement signal is converted into the swashplate angle value of feedback of oil hydraulic pump 4; Control unit 22, by the desired value of this value of feedback of contrast and setting, to both difference adoption rate control, transmits control signal to first to directional control valve 11 and second direction valve 12; Electromagnetic coil on the electromagnet of first direction valve 11 and second direction valve 12 receives after this control signal, make spool move the uninterrupted that regulates port A, namely two of regulator solution press pump 4 ports 41 and port 42 uninterrupteds, change the pressure difference at piston 133 two ends, piston 133 is moved, and then the swashplate angle of change oil hydraulic pump 4, make its desired value of following setting, to realize the object of regulator solution press pump 4 discharge capacities.In this process, slippage pump 5 provides the fluid of constant pressure always.

Control unit 22, by controlling third direction valve 143, the 5th directional control valve 145 and the 6th directional control valve 146 in hydraulic control valve group 14, can be placed in the first oil hydraulic motor 15 in system any mode of operation of following mode of operation:

Freewheel pattern:

Third direction valve 143 is placed in primary importance I, and the 5th directional control valve 145 is placed in primary importance I, and the 6th directional control valve 146 is placed in position I; The first oil hydraulic motor 15 is not driven, and the master port 151 of the first oil hydraulic motor 15 and master port 152 are connected earial drainage by port T2 and the oil tank 21 of hydraulic control valve group 14; The port 42 of oil hydraulic pump 4 ports 41 and oil hydraulic pump 4 is connected mutually by the port MC of hydraulic control valve group 14 and the housing earial drainage port one 53 of the first oil hydraulic motor 15, and the pressure limiting effect of the one-way valve 147 of being demarcated, the housing earial drainage port one 53 of the first oil hydraulic motor 15 can keep the pressure of 3ar to 5bar;

Drive pattern:

Third direction valve 143 is placed in primary importance I, and the 5th directional control valve 145 is placed in second place II, and the 6th directional control valve 146 is placed in second place II; The first oil hydraulic motor 15 is driven, and the master port 151 of the first oil hydraulic motor 15 and master port 152 are connected respectively to the port 41 of oil hydraulic pump 4 and the port 42 of oil hydraulic pump 4 by hydraulic control valve group 14; Oil hydraulic pump 4 and the first oil hydraulic motor 15 form closed hydraulic loop; Oil hydraulic pump 4 provides the first oil hydraulic motor 15 pressure oil liquids, and the housing earial drainage port one 53 of the first oil hydraulic motor 15 is connected earial drainage by port T2 and the oil tank 21 of hydraulic control valve group 14 simultaneously.

Bypass mode:

Third direction valve 143 is placed in second place II, and the 5th directional control valve 145 and the 6th directional control valve 146 can be placed in arbitrary position; Oil hydraulic pump 4 is cut off; The first oil hydraulic motor 15 is not driven, and the master port 151 of the first oil hydraulic motor 15 and the port one 52 of the first oil hydraulic motor 15 are by bypass.

Below describe the different working modes of oil hydraulic motor 15 in described system in detail.

In the normal running process of target vehicle, no matter system is in which kind of mode of operation, and slippage pump 5 is always in running order is system fuel feeding, and is subject to the restriction of the first relief valve 6 first threshold of demarcating, and the fluid of constant pressure is provided to pipeline L3; In the first direction valve 11 being directly connected with pipeline L3 or connect by pipeline and second direction valve 12 and hydraulic control valve group 14, the port P of directional control valve 143 is all filled with the fluid of constant pressure always; In the time of oil hydraulic pump 4 forward, slippage pump 5 provides constant voltage fluid by pipeline L3, the second one-way valve 8 to pipeline L2; In the time that oil hydraulic pump 4 reverses, slippage pump 5 provides constant voltage fluid by pipeline L3, the first one-way valve 7 to pipeline L1.

In the normal running process of target vehicle, no matter system is in which kind of mode of operation, and in the time that the operating conditions of the flushing valve 141 in hydraulic control valve group 14 self meets, flushing valve 141 is worked always, and the fluid earial drainage in pipeline L4 or L5 is carried out cooling.Be greater than the pressure of pipeline L5 when the pressure of pipeline L4, and when the pressure of pipeline L4 is greater than the setting pressure of the 4th relief valve 142, the port T1 earial drainage of the fluid of pipeline L4 from hydraulic control valve group 14 carries out being back to oil tank 21(cooling unit after cooling and do not illustrate in the drawings); When the pressure of pipeline L5 is greater than the pressure of pipeline L4, and the pressure of pipeline L5 is while being greater than the setting pressure of the 4th relief valve 142, and the port T1 earial drainage of the fluid of pipeline L5 from hydraulic control valve group 14 carries out after cooling being back to oil tank 21.

In the normal running process of target vehicle, in the time that front-wheel does not need to provide driving force, when namely in described Closed Hydraulic transmission, the load quality body 17 of the first oil hydraulic motor does not need to drive, the first oil hydraulic motor 15 does not need to be driven, and now the first oil hydraulic motor 15 can be in freewheel pattern.Under this pattern, third direction valve 143 is placed in primary importance I, and the 5th directional control valve 145 is placed in primary importance I, and the 6th directional control valve 146 is placed in primary importance I.Now, the port K1 of fourth direction valve 144 and port K2 communicate by oil circuit and are connected to port T1 and are communicated with oil tank 21, and the spool of fourth direction valve 144 is placed in primary importance I under the start of its two ends Returnning spring; The port one 51 of the first oil hydraulic motor 15 and port one 52 communicate by oil circuit and are connected to the port T2 of hydraulic control valve group 14 and are communicated with and carry out draining with oil tank 21; The port 41 of oil hydraulic pump 4 and port 42 communicate by oil circuit and are connected to the housing earial drainage port one 53 of the first oil hydraulic motor 15; Between oil circuit L8 and oil circuit L9, be provided with the one-way valve 147 of demarcation, in the time that the pressure of oil circuit L8 exceedes the 3rd threshold value of its setting, oil circuit L8 and oil circuit L9 connect and are communicated with oil tank 21 by port T2, to ensure oil circuit L8 maintenance necessarily and not higher than the pressure of the 3rd threshold value.

Under freewheel pattern, the port 41 of oil hydraulic pump 4 and port 42 are connected mutually, the high pressure oil of output passes to the housing earial drainage port one 53 of the first oil hydraulic motor 15 by oil circuit L8, the pressure limiting effect of the one-way valve 147 of being demarcated, the pressure value of the housing earial drainage port one 53 of the first oil hydraulic motor 15, not being the pressure value of the fluid of oil hydraulic pump 4, but the 3rd threshold value that one-way valve 147 is demarcated, is the oil pressure numerical value that is less than oil hydraulic pump 4;

Under freewheel pattern, oil hydraulic pump 4 and the first oil hydraulic motor 15 do not form hydraulic drive circuit, master port 151 and the master port 152 of the first oil hydraulic motor 15 communicate, and be communicated with earial drainage by the port T2 of hydraulic control valve group 14 with oil tank 21, the master port 151 of the first oil hydraulic motor 15 and the pressure value of master port 152 are 0bar, and under the acting in conjunction of the housing earial drainage port one 53 of the first oil hydraulic motor 15 due to oil hydraulic pump 4 and one-way valve 147, remain with the pressure value (3bar to 5bar) of the 3rd threshold value, thereby the pressure of housing earial drainage port one 53 is greater than the master port 151 of the first oil hydraulic motor 15 and the pressure of master port 152, radial plunger start in the first oil hydraulic motor 15 structures is inside contracted, the thorough separation of housing with the first oil hydraulic motor 15, eliminate the additional drag that the first oil hydraulic motor 15 produces the load quality body 17 of the first oil hydraulic motor under freewheel state.In embodiment, the housing of the first oil hydraulic motor 15 is to adopt mechanical bolt to be connected with the wheel hub of front-wheel, first rotor shaft of oil hydraulic motor 15 and the semiaxis of front-wheel are the same axises, the radial plunger of the first oil hydraulic motor 15 is exactly the semiaxis of front-wheel and separating of front-wheel hub with separating of its housing, that is to say in the time that front-wheel is subject to car body effect and rotates, the first oil hydraulic motor 15 housings rotate thereupon, and front-wheel semiaxis and motor rotor axle do not rotate, so just eliminate the first oil hydraulic motor 15, under freewheel state, front-wheel has been rotated to additional resistance, reduce the resistance of car load from car load, reduce the oil consumption of car load.

In the normal running process of target vehicle, in the time that front-wheel need to provide driving force, when namely load quality body 17 mass bodies of the first oil hydraulic motor need to be driven, the first oil hydraulic motor 15 need to be actuated to the rotation load of the load quality body 17 that overcomes the first oil hydraulic motor, and now the first oil hydraulic motor 15 is in drive pattern.Under drive pattern, third direction valve 143 is placed in primary importance I, and the 5th directional control valve 145 is placed in second place II, and the 6th directional control valve 146 is placed in second place II.Now, the port K1 of fourth direction valve 144 and port K2 are communicated with oil tank 21 by pipeline and port T1, and the spool of fourth direction valve 144 is placed in primary importance I under the start of its two ends Returnning spring; The master port 151 of the first oil hydraulic motor 15 and master port 152 form closed hydraulic loop with port 41 and the port 42 of oil hydraulic pump 4, the housing earial drainage port one 53 of the first oil hydraulic motor 15 is communicated with quick relief by the port T of hydraulic control valve group 14 with oil tank 21, making the pressure of the first oil hydraulic motor 15 housings is 0bar, reduces the load of housing oil pressure resistance to the first oil hydraulic motor 15 rotor shaft rotation works.

Oil hydraulic pump 4 is exported high-voltage oil liquid and is driven the first oil hydraulic motor 15 work to rotate, be that outputting power drives load, the housing earial drainage port one 53 of the first oil hydraulic motor 15 is directly connected to port T2 and is communicated with oil tank 21 earial drainages by the 5th directional control valve 145 and the 6th directional control valve 146, the master port 151 of the first oil hydraulic motor 15 drives radial plunger tightly to contact with the housing of the first oil hydraulic motor 15 with 152 input high-voltage oil liquids, and produce active force drives rotor shaft rotate, now the housing pressure of the first oil hydraulic motor 15 reduces to 0, reduce the resistance to motion of radial plunger, and then reduce the rotation load of the first oil hydraulic motor 15.

In addition, under drive pattern, oil hydraulic pump 4 and the first oil hydraulic motor 15 form closed hydraulic loop, can realize the first oil hydraulic motor 15 bidirectional-movements.The sense of rotation of the first oil hydraulic motor 15 is to be determined by the fluid output port of oil hydraulic pump 4, and the fluid output port of oil hydraulic pump 4 is to be determined by the swashplate angle of oil hydraulic pump 4; When the swashplate angle of oil hydraulic pump 4 is during in 0～+ 1 scope, oil hydraulic pump 4 is exported fluid from port 41 and is made oil hydraulic pump 4 forwards; When the swashplate angle of oil hydraulic pump 4 is during in-1～0 scope, oil hydraulic pump 4 is exported fluid from port 42 reverses oil hydraulic pump 4.In the time of oil hydraulic pump 4 forward, export high pressure oil from port 41, pass through hydraulic control valve group 14 and each oil circuit, pipeline transmission, input to the port one 51 of oil hydraulic motor 15, drive the first oil hydraulic motor 15 forwards; Otherwise oil hydraulic pump 4 reverses, the first oil hydraulic motor 15 reverses accordingly.

Target vehicle is in normal running process, in the time that needs gearshifts or short time stop, now the first oil hydraulic motor 15 need to be removed drive condition equally, to ensure the stable gearshift of driver or to stop, if now controlling the first oil hydraulic motor 15 is switched to freewheel pattern and is fine, but the time of considering gear shift operation or short time parking is very short, oil hydraulic motor is switched to again drive pattern at short notice, can in the closed hydraulic loop that oil hydraulic pump 4 and the first oil hydraulic motor 15 form, cause larger pressure surge like this, not only affect the operating life of hydraulic element, more may affect travel safety.Closed circuit hydraulic transmission system described in the utility model provides a kind of short time mode of operation that can fast oil hydraulic motor be removed to drive condition, i.e. the first oil hydraulic motor 15 bypass mode for this reason.This pattern is used in oil hydraulic motor under drive pattern, runs in target vehicle gearshift or short time parking situation.Under the first oil hydraulic motor 15 bypass mode, third direction valve 143 is placed in second place II, the 5th directional control valve 145 and 146 of the 6th directional control valves maintain the position (the 5th directional control valve 145 is placed in second place II, and the 6th directional control valve 146 is placed in second place II) of previous state.Now the port P of third direction valve 143 and the port A of third direction valve 143 connect, and the port T of third direction valve 143 and the port B of third direction valve 143 connect, the fluid that slippage pump 5 is exported flows to the port K1 of the oil circuit control of fourth direction valve 144, and being connected to port T1 by oil circuit, the port K2 of fourth direction valve 144 is communicated with earial drainage with oil tank 21, the spool of the pressure official post fourth direction valve 144 of the port K1 of fourth direction valve 144 and port K2 moves, be that fourth direction valve 144 is placed in second place II, now the port 41 of oil hydraulic pump 4 and port 42 are all cut off, the master port 151 of the first oil hydraulic motor 15 and master port 152 are also connected mutually by fourth direction valve 144, thereby fourth direction valve 144 has cut off the hydraulic drive circuit that oil hydraulic pump 4 and the first oil hydraulic motor 15 form, the first oil hydraulic motor 15 is by not outputting power of bypass.

After gearshift finishes, third direction valve 143 home position I, the port K1 of fourth direction valve 144 and port K2 mutually connect by oil circuit and are communicated with earial drainage by port T1 with oil tank 21, the spool of fourth direction valve 144 turns back to primary importance I by the effect of the Returnning spring at two ends, connects the transmission loop that oil hydraulic pump 4 and the first oil hydraulic motor 15 form.

Fourth direction valve 144 control of surging in the first oil hydraulic motor 15 bypass mode, can overcome the high pressure resistance in transmission loop in the time switching, the first oil hydraulic motor 15 is before and after pattern is switched simultaneously, the pressure of working connection changes little, reduce the pressure surge of first oil hydraulic motor 15 working connection that handoff procedure causes, reduced energy loss.But in this pattern, the working connection of the first oil hydraulic motor 15 exists certain pressure, therefore, for improving the operating life of oil hydraulic motor, this pattern can only be used the short time.

Claims (9)

1. a Closed circuit hydraulic transmission system, it is characterized in that, described a kind of Closed circuit hydraulic transmission system includes load quality body (17), the second oil hydraulic motor (18), the load quality body (20) of the second oil hydraulic motor, the oil tank (21) and control unit (22) of power input mechanism, hydraulic pump module (3), hydraulic control valve group (14), the first oil hydraulic motor (15), the first oil hydraulic motor;

Between power input mechanism and hydraulic pump module (3) for mechanical type is connected, between hydraulic pump module (3) and hydraulic control valve group (14) for pipeline is connected, between hydraulic control valve group (14) and the first oil hydraulic motor (15) for pipeline is connected, between hydraulic control valve group (14) and the second oil hydraulic motor (18) for pipeline is connected, hydraulic control valve group (14) is with being connected with the second oil hydraulic motor (18) pipeline with the first oil hydraulic motor (15), between the load quality body (17) of the first oil hydraulic motor (15) and the first oil hydraulic motor for mechanical type is connected, between the load quality body (20) of the second oil hydraulic motor (18) and the second oil hydraulic motor for mechanical type is connected, hydraulic pump module (3) and hydraulic control valve group (14) with and oil tank (21) pipeline be connected, control unit (22) is with being connected with hydraulic control valve group (14) signaling line with hydraulic pump module (3).

2. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, between described hydraulic pump module (3) and hydraulic control valve group (14), refer to for pipeline is connected:

The port PA of hydraulic pump module (3) is connected with the port VA pipeline of hydraulic control valve group (14), the port PC of hydraulic pump module (3) is connected with the port VC pipeline of hydraulic control valve group (14), and the port PB of hydraulic pump module (3) is connected with the port VB pipeline of hydraulic control valve group (14).

3. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, between described hydraulic control valve group (14) and the first oil hydraulic motor (15), refer to for pipeline is connected:

The port MA1 of hydraulic control valve group (14) is connected with master port 151 pipelines of the first oil hydraulic motor (15), and the port MB1 of hydraulic control valve group (14) is connected with master port 152 pipelines of the first oil hydraulic motor (15).

4. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, between described hydraulic control valve group (14) and the second oil hydraulic motor (18), refer to for pipeline is connected:

The port MB2 of hydraulic control valve group (14) is connected with master port 182 pipelines of the second oil hydraulic motor (18), and the port MA2 of hydraulic control valve group (14) is connected with master port 181 pipelines of the second oil hydraulic motor (18).

5. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, described hydraulic control valve group (14) is with being connected and referring to the second oil hydraulic motor (18) pipeline with the first oil hydraulic motor (15):

The port MC of hydraulic control valve group (14) is with being connected with the housing earial drainage port one 53 of the first oil hydraulic motor (15) and housing earial drainage port one 83 pipelines of the second oil hydraulic motor (18).

6. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, between described the first oil hydraulic motor (15) and the load quality body (17) of the first oil hydraulic motor, for mechanical type is connected, between the load quality body (20) of the second oil hydraulic motor (18) and the second oil hydraulic motor, for being connected, mechanical type refers to:

The turning axle of the load quality body (17) of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor (15) are the i.e. load transmission shaft (16) of the first oil hydraulic motor of the same axis, or the turning axle of the load quality body (17) of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor (15) are not the same axis but the load transmission shaft (16) of the first oil hydraulic motor and the rotor shaft of the first oil hydraulic motor (15), adopt spline pair to connect between the two;

The turning axle of the load quality body (20) of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor (18) are the i.e. load transmission shaft (19) of the second oil hydraulic motor of the same axis, or the turning axle of the load quality body (20) of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor (18) are not the same axis but the load transmission shaft (19) of the second oil hydraulic motor and the rotor shaft of the second oil hydraulic motor (18), adopt spline pair to connect between the two.

7. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, described hydraulic pump module (3) and hydraulic control valve group (14) with and oil tank (21) pipeline be connected and refer to:

The port T of the first direction valve (11) in hydraulic pump module (3) is connected with oil tank (21) pipeline by pipeline with the port T of second direction valve (12), the filler opening of slippage pump (5) adopts pipeline L2 to be connected with oil tank (21), and the oil outlet of the first relief valve (6) is connected with oil tank (21) pipeline;

Between port T1 in hydraulic control valve group (14) and oil tank (21), pipeline is connected, and between the port T2 in hydraulic control valve group (14) and oil tank (21), pipeline is connected.

8. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, described hydraulic pump module (3) includes power input shaft (44), oil hydraulic pump (4), slippage pump (5), the first relief valve (6), the second relief valve (9), the 3rd relief valve (10), the first one-way valve (7), the second one-way valve (8), first direction valve (11), second direction valve (12), oil hydraulic cylinder (13) and displacement transducer X;

The input shaft of power input shaft (44) and oil hydraulic pump (4), the rotor shaft of slippage pump (5) are the same axis, and the port 41 of oil hydraulic pump (4) adopts the port PA of pipeline L1 and hydraulic pump module (3), the oil outlet of the first one-way valve (7) to be connected with the filler opening of the second relief valve (9); The port 42 of oil hydraulic pump (4) adopts the port PB of pipeline L2 and hydraulic pump module (3), the oil outlet of the second one-way valve (8) to be connected with the filler opening of the 3rd relief valve (10); The swash plate (43) of oil hydraulic pump (4) is connected with one end ball pivot of the piston (133) in oil hydraulic cylinder (13);

The oil outlet of slippage pump (5) adopts port PC, the filler opening of the first relief valve (6), the filler opening of the first one-way valve (7), the filler opening of the second one-way valve (8), the oil outlet of the second relief valve (9), the oil outlet of the 3rd relief valve (10), the port P of first direction valve (11), the port P of second direction valve (12) of pipeline L3 and hydraulic pump module (3) to be connected;

The port A of first direction valve (11) adopts pipeline to be connected with the port one 32 of oil hydraulic cylinder (13), the port A of second direction valve (12) adopts pipeline to be connected with the port one 31 of oil hydraulic cylinder (13), and displacement transducer X is arranged on one end of the piston (133) in oil hydraulic cylinder (13).

9. according to a kind of Closed circuit hydraulic transmission system claimed in claim 1, it is characterized in that, described hydraulic control valve group (14) comprises flushing valve (141), the 4th relief valve (142), third direction valve (143), fourth direction valve (144), the 5th directional control valve (145), the 6th directional control valve (146) and the one-way valve (147) of demarcating;

The port A of flushing valve (141) is connected with the port VA of hydraulic control valve group (14), the port P of fourth direction valve (144) by pipeline L4, the port B of flushing valve (141) is connected with the port VB of hydraulic control valve group (14), the port T of fourth direction valve (144) by pipeline L5, and the port T of flushing valve (141) is connected with the filler opening of the 4th relief valve (142) by pipeline;

The port P of third direction valve (143) is connected with the port VC of hydraulic control valve group (14) by pipeline; The port T of third direction valve (143) is connected with the port T1 of hydraulic control valve group (14) by pipeline; The port A of third direction valve (143) is connected with oil circuit control port K2 with the oil circuit control port K1 of fourth direction valve (144) by pipeline successively with port B;

The port P of fourth direction valve (144) is connected with the port VA of hydraulic control valve group (14) by pipeline L4; The port T of fourth direction valve (144) is connected with the port VB of hydraulic control valve group (14) by pipeline L5; The port A of fourth direction valve (144) is connected with the port P of the 5th directional control valve (145) by pipeline; The port B of fourth direction valve (144) is connected with the port T of the 6th directional control valve (146) by pipeline;

The port T of the 5th directional control valve (145) is connected by pipeline L9 and the port P of the 6th directional control valve (146), the port T2 of hydraulic control valve group (14), and the port A of the 5th directional control valve (145) is connected with the port MA1 of hydraulic control valve group (14), the port MA2 of hydraulic control valve group (14) by oil circuit L6; The port B of the 5th directional control valve (145) is connected with the port B of the 6th directional control valve (146), the port MC of hydraulic control valve group (14) by pipeline L8;

The port A of the 6th directional control valve (146) is connected with the port MB1 of hydraulic control valve group (14), the port MB2 of hydraulic control valve group (14) by pipeline L7, and the one-way valve (147) of demarcation is arranged on and connects between the 5th directional control valve (145) and the pipeline L8 and pipeline L9 of the 6th directional control valve (146).