Hydraulic drive of walking machine with pressure regulator

Abstract

FIELD: machinery.SUBSTANCE: invention which relates to volumetric hydraulic drives of mobile machines and can be used in electrohydraulic systems as a drive for controlling the chassis. A hydraulic drive for a walking machine, containing a pumping station, travel hydraulic cylinders and electro-hydraulic distributors for controlling the position of the travel hydraulic cylinders. The travel hydraulic cylinders are equipped with position sensors, and the electro-hydraulic distributors for controlling the position of the travel hydraulic cylinders are multi-position. The pumping station, connected to the hydraulic travel cylinders, contains an adjustable pump, powered by a drive motor, a tank with working fluid and a load-sensitive pressure regulator, including interconnected safety valves “or”, a filter, a multi-position hydraulic distributor and two hydraulic cylinders for controlling the characteristic working volume of the pump.EFFECT: improvement in the stability of movement and energy efficiency of the walking machine.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 equipment 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 E02F 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 E02F 9 / 00).

[0005] The disadvantage of the prototype is the unstable operation of the multi-motor hydraulic drive in transient modes, significant power consumption when operating in low modes, and a static error caused by the mutual influence of the circuits on each other under different loads on the actuator hydraulic motors.

[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 claimed invention is an improvement in the stability of movement and energy efficiency due to the introduction of a hydromechanical pressure regulator into the hydraulic drive, which eliminates unstable operation in transient modes, minimal power consumption when operating in low modes, and a static error caused by the mutual influence of circuits on each other under different loads on the actuator hydraulic cylinders of the stroke.

[0008] The stated problem is solved, and the technical result is achieved by a hydraulic drive of a walking machine, containing a pumping station, travel hydraulic cylinders and electro-hydraulic distributors for controlling the position of the travel hydraulic cylinders, in which, unlike the prototype, the travel hydraulic cylinders are equipped with position sensors, the electro-hydraulic distributors for controlling the position of the travel hydraulic cylinders are made multi-position, and the pumping station, connected to the travel hydraulic cylinders, contains an adjustable pump, powered by a drive motor, a tank with working fluid and a load-sensitive pressure regulator, including interconnected safety valves "or", a filter, a multi-position hydraulic distributor and two hydraulic cylinders for controlling the characteristic working volume of the pump.

[0009] The technical result is achieved by maintaining a constant pressure in the system during transient conditions and during standby operation at minimum power consumption through pump regulation. Changes in system pressure, caused by a command to move the piston rods of the hydraulic cylinders, as well as by planned or unplanned load changes, are transmitted to the hydraulic cylinders of the hydromechanical pressure regulator, which change the pump's characteristic working volume, adapting to the situation and maintaining a constant system pressure.

[0010] The essence of the invention is explained by a drawing, which depicts a basic hydraulic diagram of a walking machine hydraulic drive.

[0011] The walking machine's hydraulic drive includes a pump station. The pump station consists of: an adjustable pump 1, a drive motor 2, a tank 3 with working fluid, safety valves 4, and a filter 5. The travel hydraulic cylinders 6, equipped with feedback sensors 7, are controlled by multi-position electro-hydraulic valves 8.

[0012] The pressure regulator contains “or” valves, a multi-position hydraulic distributor 10 and two hydraulic cylinders 11 and 12 for controlling the characteristic working volume of the pump.

[0013] The walking machine hydraulic drive with a pressure regulator operates as follows. The working fluid from tank 3 is supplied by pump 1, powered by drive motor 2, to hydraulic stroke cylinders 6, equipped with feedback sensors 7. The piston rod of each hydraulic stroke cylinder 6 is movable, and therefore can change the position of the walking machine's travel device, by sending a control command to 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 piston rods of hydraulic cylinders 6. Safety valves 4 prevent damage to the hydraulic drive due to overload or clogging of filter 5. By sucking fluid from tank 3, pump 1 also compensates for volumetric leaks in hydraulic motors 6.

[0014] The pressure regulator operates as follows. When there are no control signals to the throttling electro-hydraulic distributors 8, the pump reaches minimum capacity, controlling the minimum characteristic working volume of the pump using hydraulic cylinder 11. The piston of cylinder 12 is then displaced to the extreme left position. The pressure in the system is maintained constant at the nominal value. When control signals are applied to the throttling electro-hydraulic distributors 8, the piston rods of the hydraulic cylinders begin to move. The consumption of working fluid from the pump increases. To compensate for the pressure drop, the pressure regulator is activated. The spring of multi-position hydraulic distributor 10 shifts the spool by an amount proportional to the pressure drop.At the same time, pressure is supplied to the piston chamber of hydraulic cylinder 12 through multi-position hydraulic distributor 10, which changes the pump's characteristic working volume, increasing its flow rate and compensating for the pressure drop, bringing the value to the nominal pressure. The regulator sets the supply pressure sufficient to overcome the external load and ensure the best energy and dynamic performance.

[0015] The claimed invention makes it possible to improve the stability of movement and the energy efficiency of a walking machine by maintaining a constant pressure in a multi-motor hydraulic drive, eliminating unstable operation in transient modes, minimal power consumption when operating in low modes, and a static error caused by the mutual influence of circuits on each other under different loads on the actuator hydraulic motors.

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 travel hydraulic cylinders are equipped with position sensors, the electro-hydraulic distributors for controlling the position of the travel hydraulic cylinders are multi-position, and the pump station, connected to the travel hydraulic cylinders, contains an adjustable pump operated by a drive motor, a tank with a working fluid and a load-sensitive pressure regulator, including interconnected safety valves "or", a filter, a multi-position hydraulic distributor and two hydraulic cylinders for controlling the characteristic working volume of the pump.

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