Hydrostatic engineering machinery drive axle

Abstract

The utility model relates to a hydrostatic engineering machinery drive axle, which comprises an engine, a gearbox, a front transmission shaft, a front axle drive, a rear transmission shaft and a rear axle drive, the hydrostatic transmission system comprises a variable pump connected with the engine, a hydraulic motor connected with the input end of the gearbox and a reversing control valve connected between the variable pump and the hydraulic motor, and the variable pump, the reversing control valve and the hydraulic motor are connected to form a closed hydraulic loop; the front output shaft is provided with an off-axle clutch for controlling the front transmission shaft to be combined with or disconnected from the front output shaft, and the hydrostatic transmission system is connected with the off-axle clutch and controls the off-axle clutch to be combined with or disconnected from the front output shaft. The closed hydraulic loop is used for replacing a hydraulic torque converter, the transmission efficiency is improved, the energy consumption is reduced, the working condition adaptability of the whole machine is improved, and good fuel economy is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a static hydraulic engineering machinery drive axle belongs to static hydraulic engineering machinery drive technical field. BACKGROUND

[0002] The engineering machinery drive axle assembly is an important component in engineering machinery, is used for transmission power and carries weight, the drive axle assembly passes through the power provided by the engine, transmits power to the wheels of the vehicle, thereby driving the vehicle to advance or retreat, simultaneously the drive axle assembly also bears the function of carrying the weight of the vehicle and steering, plays a vital role in engineering machinery, and the advantages and disadvantages of its performance directly affect the operation efficiency and safety of engineering machinery, most engineering machinery is designed based on the chassis, the traditional engineering machinery drive axle is mainly composed of an engine, a hydraulic torque converter, a gearbox and a front / rear drive axle, forms the power transmission route by the engine, the hydraulic torque converter, the gearbox and the front / rear drive axle.The working efficient area of the hydraulic torque converter is narrow, and the transmission efficiency is low, in the working condition complex, load severe operation environment, the engine power cannot be effectively utilized, causes the performance of the whole machine to be unable to fully play and fuel economy is low, leads to the transmission efficiency of the chassis whole body only between 70-80%, transmission efficiency is low, 20-30% energy is wasted and lost.The fuel economy of static hydraulic drive technology is better, so it is more and more widely used in the field of engineering machinery, agricultural machinery and other fields, the static hydraulic drive machine type on the market mostly adopts the technical route of "variable pump + fixed displacement motor", in the vehicle operation and transfer mode, there are the following disadvantages:

[0003] 1. The whole vehicle adopts four-wheel drive when running at high speed under light load or operating at low speed under heavy load, power loss is large, causing poor working condition adaptability of the whole machine.

[0004] 2. The front and rear axles are arranged symmetrically and connected with the output shafts of the gearbox, which has poor adaptability to the working ground and affects the passing performance of the whole machine.

[0005] 3. The mechanical gear shifting transmission has large or small step difference, has large impact during gear shifting, has high requirement for the matching of speed difference during gear shifting process, has poor adaptability, and causes poor driving comfort. INVENTION CONTENTS

[0006] The static hydraulic engineering machinery drive axle provided by the utility model changes the advancing or retreating direction of the whole machine through the rotation direction change of the hydraulic motor, realizes the driving walking of the whole machine, replaces the hydraulic torque converter with a closed hydraulic circuit, improves transmission efficiency, reduces energy consumption, improves the working condition adaptability of the whole machine, and realizes good fuel economy.

[0007] To achieve the above purpose, the utility model adopts the technical scheme that:

[0008] Hydrostatic engineering machinery drive axle, comprising engine, gearbox, front transmission shaft connected with front output shaft of gearbox, front axle drive connected with front transmission shaft, rear transmission shaft connected with rear output shaft of gearbox and rear axle drive connected with rear transmission shaft, characterized in that: the engine and gearbox are connected through hydrostatic transmission system, the hydrostatic transmission system comprises variable pump connected with engine, hydraulic motor connected with input end of gearbox, reversing control valve connected between variable pump and hydraulic motor, the variable pump, reversing control valve and hydraulic motor are connected to form closed hydraulic circuit, the front output shaft is provided with off axle clutch for controlling combination or disconnection of front transmission shaft and front output shaft, the hydrostatic transmission system is connected with off axle clutch, and the off axle clutch is controlled to be disconnected or combined.

[0009] Preferably, the rear output shaft and front output shaft of the gearbox are arranged in parallel, the rear output shaft is located above the front output shaft, the radius of the front wheel in the front axle drive is smaller than the radius of the rear wheel in the rear axle drive, and the wheel shaft of the rear wheel is higher than the wheel shaft of the front wheel.

[0010] Preferably, the gearbox comprises a box body, the box body is provided with an input shaft connected with the output end of the hydraulic motor, an intermediate shaft connected with the input shaft through gear meshing, a rear output shaft connected with the intermediate shaft through gear meshing, and a front output shaft connected with the rear output shaft through gear meshing, and the input shaft, the intermediate shaft, the rear output shaft and the front output shaft are arranged in parallel from top to bottom, and the rear transmission shaft is connected with the rear drive axle through a universal joint.

[0011] Preferably, the hydrostatic transmission system further comprises a constant pump connected with the engine and a gear shift control valve connected with the constant pump, the gear shift control valve is connected with the off axle clutch to control the off axle clutch to be disconnected or combined, and the oil inlet end of the constant pump is connected to the oil tank of the gearbox.

[0012] Preferably, the input shaft is fixed with a first-gear driving gear and a second-gear driving gear, the intermediate shaft is provided with a first-gear driven gear meshing with the first-gear driving gear and a second-gear driven gear meshing with the second-gear driving gear through a loose sleeve shaft, the intermediate shaft is fixed with a gear shift clutch controlled by the hydrostatic transmission system and a rear driving gear meshing with the rear output shaft, the gear shift clutch is located between the first-gear driven gear and the second-gear driven gear, and the gear shift clutch is combined with the first-gear driven gear when moving to the left and combined with the second-gear driven gear when moving to the right.

[0013] Preferably, the gear shift control valve is connected with the gear shift clutch to control the gear shift clutch to shift gears.

[0014] Preferably, the rear output shaft is fixed with a rear driven gear meshing with the rear driving gear and a front driving gear, and the front output shaft is fixed with a front driven gear meshing with the front driving gear.

[0015] Preferably, the shift clutch and the disconnect clutch are both combined sleeve clutches controlled by the transmission control valve.

[0016] Preferably, the shift clutch and the disconnect clutch are both friction plate wet clutches controlled by the transmission control valve.

[0017] The utility model has the advantages of:

[0018] The hydraulic engineering machinery drive axle of the utility model, the variable pump, the reversing control valve and the hydraulic motor are connected to form a closed hydraulic circuit, the vehicle controller sends a control signal to the reversing control valve, controls the reversing of the reversing control valve, forms the change of the liquid flow direction in the closed hydraulic circuit, so that the change of the rotation direction of the hydraulic motor is realized, the change of the advancing direction of the whole machine is formed by the change of the rotation direction of the hydraulic motor, the driving walking of the whole machine is realized, the hydraulic torque converter is replaced by the closed hydraulic circuit, the transmission efficiency is improved, the energy consumption is reduced, and the fuel economy is improved; the disconnect clutch is installed on the front output shaft of the gearbox, the disconnect clutch is controlled to be disconnected by the hydrostatic transmission system when the whole machine is running at high speed under light load, so that the front drive axle does not participate in driving, and only the rear drive axle is used to drive the whole machine, the power loss in the process of high-speed running is reduced, the disconnect clutch is controlled to be combined by the hydrostatic transmission system when the whole machine is working under heavy load at low speed, so that the front and rear drive axles synchronously drive the whole machine, the traction of the whole machine is improved, the working efficiency is improved, and the working condition adaptability of the whole machine is improved, so that good fuel economy is realized.

[0019] The front and rear output shafts in the gearbox are arranged in parallel and have different heights, so that the radius of the rear axle is greater than that of the front axle, the ground adaptability and passability of the whole machine are improved, the friction plate wet clutch is adopted, the speed difference matching requirement of the corresponding shaft in the shifting process is not high, the risk of gear collision in the movement process of the clutch can be avoided, the safety of the clutch action is higher, the adaptability is stronger, and the driving comfort can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 It is a schematic view of the hydrostatic engineering machinery drive axle in embodiment one.

[0021] Fig. 2 It is a schematic view of the hydrostatic engineering machinery drive axle in embodiment two. DETAILED DESCRIPTION

[0022] The embodiments of the utility model will be described in detail below. Figs. 1-2 The embodiments of the utility model will be described in detail below. Embodiment one:

[0023] The static hydraulic engineering machinery drive axle comprises an engine 1, a gearbox 2, a front transmission shaft 3 connected with a front output shaft 20 of the gearbox 2, a front axle drive 4 connected with the front transmission shaft 3, a rear transmission shaft 5 connected with a rear output shaft 21 of the gearbox 2 and a rear axle drive 6 connected with the rear transmission shaft 5, characterized in that the engine 1 and the gearbox 2 are connected through a static hydraulic transmission system 7, the static hydraulic transmission system 7 comprises a variable pump 71 connected with the engine 1, a hydraulic motor 72 connected with an input end of the gearbox 2, a reversing control valve 73 connected between the variable pump 71 and the hydraulic motor 72, the variable pump 74, the reversing control valve 72 and the hydraulic motor 72 are connected to form a closed hydraulic circuit, a bridge disconnect clutch 8 for controlling the combination or disconnection of the front transmission shaft 3 and the front output shaft 20 is arranged on the front output shaft 20, the static hydraulic transmission system 7 is connected with the bridge disconnect clutch 8, and the bridge disconnect clutch 8 is controlled to be disconnected or combined.

[0024] In the static hydraulic engineering machinery drive axle, the variable pump 71, the reversing control valve 73 and the hydraulic motor 72 are connected to form a closed hydraulic circuit, a control signal is sent to the reversing control valve 73 by a vehicle controller, the reversing control valve 73 is controlled to reverse, the transformation of the liquid flow direction in the closed hydraulic circuit is formed, the transformation of the rotating direction of the hydraulic motor 72 is realized, the driving direction of the whole machine is changed through the transformation of the rotating direction of the hydraulic motor 72, the driving walking of the whole machine is realized, the hydraulic torque converter is replaced by the closed hydraulic circuit, the transmission efficiency is improved, the energy consumption is reduced, and the fuel economy is improved; the bridge disconnect clutch 8 is arranged on the front output shaft 20 of the gearbox, the bridge disconnect clutch 8 is controlled to be disconnected by the static hydraulic transmission system 7 when the whole machine is in a light load and high speed running state, so that the front drive axle does not participate in driving, and only the rear drive axle is used to drive the whole machine, the power loss in the high speed running process is reduced, the bridge disconnect clutch 8 is controlled to be combined by the static hydraulic transmission system 7 when the whole machine is in a heavy load and low speed operation state, so that the front drive axle and the rear drive axle synchronously drive the whole machine, the traction of the whole machine is improved, the operation efficiency is improved, and the working condition adaptability of the whole machine is improved, and good fuel economy is realized.

[0025] In the static hydraulic engineering machinery drive axle, the rear output shaft 21 and the front output shaft 20 of the gearbox 2 are arranged in parallel, the rear output shaft 21 is located above the front output shaft 21, the radius of the front wheel in the front axle drive 4 is smaller than the radius of the rear wheel in the rear axle drive 6, and the wheel shaft of the rear wheel is higher than the wheel shaft of the front wheel. The front output shaft and the rear output shaft in the gearbox 2 are arranged in parallel and at different heights, so that the rear axle tire is lifted, the radius of the rear wheel is greater than the radius of the front wheel, and the ground adaptability and passability of the whole machine are improved.

[0026] The gearbox 2 comprises a box body, an input shaft 22 connected with the output end of the hydraulic motor 72, an intermediate shaft 23 connected with the input shaft 22 through gear engagement, a rear output shaft 21 connected with the intermediate shaft 23 through gear engagement, a front output shaft 20 connected with the rear output shaft 21 through gear engagement, the input shaft 22, the intermediate shaft 23, the rear output shaft 21 and the front output shaft 20 are arranged in parallel from top to bottom, and the rear transmission shaft 5 is connected with the rear drive axle 6 through a universal joint. The gearbox 2 adopts a parallel shaft structure, which can form parallel and staggered high front and rear output shafts, facilitate the arrangement of a gear shifting mechanism, reduce the space volume of the gearbox, and is beneficial to the arrangement of the drive axle on the chassis of the whole vehicle.

[0027] The static hydraulic transmission system 7 further comprises a constant delivery pump 74 connected with the engine 1 and a gear shifting control valve 75 connected with the constant delivery pump 74, the gear shifting control valve 75 is connected with the disconnect clutch 8 to control the disconnect clutch 8 to be disconnected or combined, and the oil inlet end of the constant delivery pump 74 is connected with the oil tank of the gearbox 2. Under the drive of the engine 1, the constant delivery pump 74 pumps the oil in the gearbox 2 into the gear shifting control valve 72, and the piston in the gear shifting control valve 72 drives the disconnect clutch 8 to act under the push of the oil, so as to form the disconnection or combination of the disconnect clutch 8.

[0028] The input shaft 22 is fixed with a first-gear driving gear Z3 and a second-gear driving gear Z1, the intermediate shaft 23 is provided with a first-gear driven gear Z4 engaged with the first-gear driving gear Z3 and a second-gear driven gear Z2 engaged with the second-gear driving gear Z1 through a loose shaft, the intermediate shaft 23 is fixed with a gear shifting clutch 9 controlled by the static hydraulic transmission system 7 and a rear driving gear Z5 engaged with the rear output shaft 21, the gear shifting clutch 9 is located between the first-gear driven gear Z4 and the second-gear driven gear Z2, the gear shifting clutch 9 is combined with the first-gear driven gear Z4 when moving to the left and is combined with the second-gear driven gear Z2 when moving to the right. The first-gear driven gear Z4 and the second-gear driven gear Z2 are rotatable relative to the intermediate shaft 23 and are arranged on the left and right sides of the gear shifting clutch 9, and the first-gear driven gear Z4 and the second-gear driven gear Z2 do not drive the intermediate shaft 23 to rotate when not being combined with the gear shifting clutch 9, that is, no power is transmitted. When the static hydraulic transmission system 7 controls the gear shifting clutch 9 to move and be combined with the first-gear driven gear Z4, the first-gear driven gear Z4 drives the intermediate shaft 23 to rotate with the first-gear driving gear Z3, and the power is transmitted to the rear output shaft 21 through the rear driving gear Z5. When the static hydraulic transmission system 7 controls the gear shifting clutch 9 to move and be combined with the second-gear driven gear Z2, the second-gear driven gear Z2 drives the intermediate shaft 23 to rotate with the second-gear driving gear Z1, and the power is transmitted to the rear output shaft 21 through the rear driving gear Z5.

[0029] The variable speed control valve 7 is connected with the shift clutch 9 to control the shift of the shift clutch 9. The piston in the variable speed control valve 72 is pushed by the oil to control the action of the shift clutch 9. When the shift clutch 9 is combined with the first gear driven gear Z4, the gearbox outputs the first gear power. When the shift clutch 9 is combined with the second gear driven gear Z2, the gearbox outputs the second gear power. When the shift clutch 9 is in the intermediate position, the gearbox is in the neutral gear and does not output power.

[0030] The rear output shaft 21 is fixed with the rear driven gear Z6 engaged with the rear driving gear Z5 and the front driving gear Z7. The front output shaft 20 is fixed with the front driven gear Z8 engaged with the front driving gear Z7. When the shift clutch 9 is combined with the first gear driven gear Z4, the power transmission route of the gearbox is hydraulic motor 72-first gear driving gear Z3-first gear driven gear Z4-rear driving gear Z5-rear driven gear Z6-front driving gear Z7-front driven gear Z8. When the shift clutch 9 is combined with the second gear driven gear Z2, the power transmission route of the gearbox is hydraulic motor 72-second gear driving gear Z1-second gear driven gear Z2-rear driving gear Z5-rear driven gear Z6-front driving gear Z7-front driven gear Z8. When the disconnect clutch 8 is combined, the power of the gearbox is transmitted to the rear drive axle 6 through the rear driven gear Z6 and to the front drive axle 4 through the front driven gear Z8. The front and rear drive axles drive the whole machine synchronously. At this time, the whole machine is in the low-speed heavy-load working condition. When the disconnect clutch 8 is disconnected, the power of the gearbox is transmitted to the rear drive axle 6 through the rear driven gear Z6. Only the rear drive axle drives the whole machine. At this time, the whole machine is in the light-load high-speed running condition.

[0031] The shift clutch 9 and the disconnect clutch 8 are both combined tooth sleeve clutches controlled by the variable speed control valve 75. The combined tooth sleeve clutch is connected with the piston in the variable speed control valve 75. The quantitative pump 74 driven by the engine 1 pumps the oil in the gearbox 2 into the variable speed control valve 72 to make the piston drive the combined tooth sleeve to move left and right along the axial direction under the push of the oil, realizing the combination or separation of the combined tooth sleeve clutch with the first gear driven gear or the second gear driven gear. The combined tooth sleeve clutch requires corresponding speed sensors to be installed on the input shaft, the intermediate shaft, the rear output shaft and the front output shaft. The real-time speed information of the corresponding shafts is sent to the whole machine controller through the speed sensors. The whole machine controller sends signals to the control variable speed control valve 75 to control the movement of the combined tooth sleeve clutch to meet the matching requirements of the speed difference in the shift process, thereby preventing the combined tooth sleeve from colliding with the corresponding gear when it is combined. Example two:

[0032] The difference from the embodiment one is that the shift clutch 9 and the tripping clutch 8 are both friction plate wet clutches controlled by the shift control valve 75. The friction plate wet clutch is adopted, the speed difference matching requirement of the corresponding shaft in the shift process is not high, the risk of gear collision in the clutch movement process can be avoided, the safety of the clutch action is higher, the adaptability is stronger, and the driving comfort can be improved.

[0033] The technical solutions of the embodiments of the utility model are completely described above in combination with the drawings, and it should be noted that the described embodiments are only part of the embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative labor belong to the protection scope of the utility model.

Claims

1. A hydrostatically driven bridge of a construction machine comprising an engine, a gearbox, a front drive shaft connected to a front output shaft of the gearbox, a front axle drive connected to the front drive shaft, a rear drive shaft connected to a rear output shaft of the gearbox, and a rear axle drive connected to the rear drive shaft, characterized in that: The engine and the gearbox are connected through a hydrostatic transmission system, the hydrostatic transmission system comprises a variable pump connected with the engine, a hydraulic motor connected with the input end of the gearbox, a reversing control valve connected between the variable pump and the hydraulic motor, the variable pump, the reversing control valve and the hydraulic motor are connected to form a closed hydraulic circuit, a disconnect clutch is arranged on the front output shaft to control the combination or disconnection of the front transmission shaft and the front output shaft, the hydrostatic transmission system is connected with the disconnect clutch, and the disconnect clutch is controlled to be disconnected or combined.

2. The hydrostatically-actuated engineering vehicle drive axle defined in claim 1, wherein: The rear output shaft and the front output shaft of the gearbox are arranged in parallel, the rear output shaft is located above the front output shaft, the radius of the front wheel in the front axle drive is smaller than the radius of the rear wheel in the rear axle drive, and the wheel shaft of the rear wheel is higher than the wheel shaft of the front wheel.

3. The hydrostatically-actuated engineering vehicle drive axle defined in claim 2, wherein: The gearbox comprises a gearbox body, the gearbox body is provided with an input shaft connected with the output end of the hydraulic motor, an intermediate shaft connected with the input shaft through gear meshing, a rear output shaft connected with the intermediate shaft through gear meshing, and a front output shaft connected with the rear output shaft through gear meshing, the input shaft, the intermediate shaft, the rear output shaft and the front output shaft are arranged in parallel from top to bottom, and the rear transmission shaft is connected with the rear drive axle through a universal joint.

4. The hydrostatically-actuated engineering vehicle drive axle defined in claim 3, wherein: The hydrostatic transmission system further comprises a constant pump connected with the engine and a gear shifting control valve connected with the constant pump, the gear shifting control valve is connected with the disconnect clutch to control the disconnect clutch to be disconnected or combined, and the oil inlet end of the constant pump is connected with the oil tank of the gearbox.

5. The hydrostatically-actuated engineering vehicle drive axle defined in claim 4, wherein: The input shaft is fixed with a first-gear driving gear and a second-gear driving gear, the intermediate shaft is provided with a first-gear driven gear meshing with the first-gear driving gear and a second-gear driven gear meshing with the second-gear driving gear through a loose sleeve shaft, the intermediate shaft is fixed with a gear shifting clutch controlled by the hydrostatic transmission system and a rear driving gear meshing with the rear output shaft, the gear shifting clutch is located between the first-gear driven gear and the second-gear driven gear, the gear shifting clutch is combined with the first-gear driven gear when moving to the left, and the gear shifting clutch is combined with the second-gear driven gear when moving to the right.

6. The hydrostatically-actuated engineering vehicle drive axle defined in claim 5, wherein: The gear shifting control valve is connected with the gear shifting clutch to control the gear shifting clutch to shift gears.

7. The hydrostatically-actuated engineering vehicle drive axle of claim 5, wherein: The rear output shaft is fixed with a rear driven gear meshing with the rear driving gear and a front driving gear, and the front output shaft is fixed with a front driven gear meshing with the front driving gear.

8. The hydrostatically-actuated engineering vehicle drive axle of claim 5, wherein: The gear shifting clutch and the disconnect clutch are both combined tooth sleeve clutches controlled by the gear shifting control valve.

9. The hydrostatically-actuated engineering vehicle drive axle of claim 4, wherein: The gear shifting clutch and the disconnect clutch are both friction plate wet clutches controlled by the gear shifting control valve.

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