Hydraulic drive of walking machine with additional feedback on dynamic pressure

Abstract

FIELD: machinery.SUBSTANCE: invention relates to volumetric hydraulic drives of mobile machines and can be used in electrohydraulic systems as a drive for controlling the chassis. The hydraulic drive of the walking machine comprises a pump station, hydraulic travel cylinders and electro-hydraulic distributors for controlling the position of the hydraulic travel cylinders. The pumping station comprises an adjustable pump, a drive motor, a tank with working fluid, safety valves and a filter and is connected to hydraulic travel cylinders equipped with feedback sensors. The electro-hydraulic distributors are multi-position. The hydraulic drive additionally comprises hydromechanical feedback on dynamic pressure of the hydraulic stroke cylinders, which includes a valve connected to the cavities of the hydraulic stroke cylinders, and also connected to a throttle, a spring-loaded plunger, and pushers with adjustable springs. The pushers themselves are mechanically connected to each other and linked via a rocker arm to a multi-position three-way distributor located inside the piston, which is mechanically connected to the pump.EFFECT: stable output characteristics and optimal power consumption of the pump depending on the actual loads acting on the actuator hydraulic cylinders.1 cl, 1 dwg

Description

[0001] The invention relates to volumetric hydraulic drives of mobile machines and can be used in electrohydraulic systems as a drive for controlling the chassis.

[0002] A hydraulic drive for the running gear of a walking excavator is known, which contains: two pumps that control the movement of the machine using hydraulic cylinders, the speed of which is regulated by a throttle, and the reverse is provided by three-position four-way hydraulic distributors (patent SU 1341340 A2, 30.09.1987, IPC E02 F 9 / 04).

[0003] The disadvantage of the analog is the instability of output characteristics and insufficient positioning accuracy.

[0004] The closest in technical essence is the hydraulic drive of the excavator walking mechanism, which contains a pumping station including two pumps, one of which is designed to control pilot hydraulic distributors that provide control of three-position four-way hydraulic distributors that direct the working fluid under high pressure to the travel hydraulic cylinders (patent RU 152936 U1, 06 / 27 / 2015, IPC E02 F 9 / 00).

[0005] The disadvantage of the prototype is the unstable operation of the multi-motor hydraulic drive in transient modes due to the power consumption of the pumping unit, which does not correspond to the control commands, non-stationary or random loads acting on the actuator hydraulic cylinders of the walking machine drive during its operation.

[0006] The objective of the invention is to expand the functional capabilities and ensure insensitivity to the load of the hydraulic drive of a walking machine.

[0007] The technical result of the invention is an increase in the stability and accuracy of the operation of the electrohydraulic drive of a walking machine due to additional hydromechanical feedback on the dynamic pressure of the hydraulic stroke cylinders, which changes the working volume of the pump depending on the actual magnitude of pressure fluctuations in the cavities of the hydraulic stroke cylinders under a load of a variable or random nature.

[0008] The stated problem is solved, and the technical result is achieved by the fact that in the hydraulic drive of the walking machine, containing a pumping station, hydraulic stroke cylinders and electro-hydraulic distributors for controlling the position of the hydraulic stroke cylinders, unlike the prototype, the pumping station contains an adjustable pump, a drive motor, a tank with a working fluid, safety valves and a filter and is connected to the hydraulic stroke cylinders equipped with feedback sensors, the electro-hydraulic distributors are made multi-position, the hydraulic drive additionally contains hydromechanical feedback on the dynamic pressure of the hydraulic stroke cylinders, including a valve connected to the cavities of the hydraulic stroke cylinders, and also connected to a throttle, a spring-loaded plunger, pushers with adjustable springs, wherein the pushers themselves are connected to each other mechanically and are connected through a rocker arm to a multi-position three-way distributor located inside the piston, which is mechanically connected to the pump.

[0009] The essence of the invention is explained by a drawing, which depicts a basic hydraulic diagram of a walking machine hydraulic drive.

[0010] The walking machine hydraulic drive contains a pumping station, the pumping station includes: an adjustable pump 1, a drive motor 2, a tank 3 with working fluid, safety valves 4 and a filter 5. The control of the travel hydraulic cylinders 6, equipped with feedback sensors 7, is carried out by multi-position electro-hydraulic distributors 8.In turn, the cavities of the hydraulic cylinders of the stroke 6 are connected with a hydromechanical device of additional feedback on dynamic pressure, which includes valves "or" 9, connected to the cavities of the hydraulic cylinders of the stroke 6, and also connected to the throttle 10, the spring-loaded plunger 11, the pushers 12 and 13, the springs of which are adjusted from the outside, and the pushers 12 and 13 themselves are connected to each other mechanically and at the same time connected through the rocker arm 14 with the multi-position three-way distributor 15, located inside the piston 16, connected to the discharge line of the pump 1 and mechanically connected to the regulator of the characteristic working volume of the pump 1.

[0011] In the hydraulic drive of the walking machine with a hydromechanical dynamic pressure feedback device, the working fluid from the tank 3 is supplied by the pump 1, powered by the drive motor 2, to the hydraulic stroke cylinders 6, equipped with feedback sensors 7. The rod of each hydraulic stroke cylinder 6 has the ability to move, and therefore the ability to change the position of the walking machine's travel device, by sending a control command to the multi-position electro-hydraulic distributors 8. These multi-position electro-hydraulic distributors 8 determine, depending on the magnitude of the control signal, the speed and direction of movement of the rods of the hydraulic cylinders 6. Safety valves 4 prevent damage to the hydraulic drive due to overload or clogging of the filter 5. By sucking fluid from the tank 3, pump 1 also compensates for volumetric leaks in the hydraulic stroke cylinders 6.

[0012] The hydromechanical dynamic pressure feedback device begins to operate when pressure fluctuations occur in the cavities of the hydraulic stroke cylinders 6 of the walking machine under a variable or random load. When pressure fluctuations occur in the cavities of the hydraulic cylinders 6, an information signal in the form of dynamic pressure is sent through valves 9 to the hydromechanical feedback device, which contains a throttle 10 connected to a spring-loaded plunger 11 and pushers 12 and 13 equipped with adjustable springs. Under the action of the resulting pressure differential in the cavities of pushers 12 and 13, which is equal in value to the pressure differential across hydraulic cylinders 6, rocker arm 14 moves, which in turn leads to the displacement of multi-position three-way distributor 15 located in piston 16.The movement of piston 16, which is mechanically connected to pump 1, leads to a change in the flow rate of pump 1 in accordance with the corrective signal of the hydromechanical feedback device.

[0013] Thus, the claimed hydraulic drive of a walking machine with hydromechanical feedback on the dynamic pressure of the travel hydraulic cylinders allows for expanding its functional capabilities, ensuring stable output characteristics and optimal power consumption of the pump depending on the actual loads acting on the actuator travel hydraulic cylinders.

Claims

A hydraulic drive for a walking machine comprising a pump station, travel hydraulic cylinders and electro-hydraulic distributors for controlling the position of the travel hydraulic cylinders, characterized in that the pump station comprises an adjustable pump, a drive motor, a tank with working fluid, safety valves and a filter and is connected to the travel hydraulic cylinders equipped with feedback sensors, the electro-hydraulic distributors are made multi-position, the hydraulic drive additionally comprises hydro-mechanical feedback for the dynamic pressure of the travel hydraulic cylinders, including a valve connected to the cavities of the travel hydraulic cylinders, and also connected to a throttle, a spring-loaded plunger, pushers with adjustable springs, wherein the pushers themselves are mechanically connected to each other and connected through a rocker arm to a multi-position three-way distributor located inside the piston, which is mechanically connected to the pump.

Images