Displacement Control Unit

Abstract

A control unit (2) of a hydraulic unit comprising a control piston (3) slidably arranged in a control cylinder (4) for servo pressure at a first outlet (8) of the control unit (2) (P 2 ) to provide hydraulic fluid suitable for the displacement of the hydraulic unit. Servo pressure (P 2 ) is proportional to the sum of the internal force of the hydraulic unit and the operating force acting on the control unit (2). The hydraulic fluid provided at the outlet (8) is at the inlet (7) of the control unit (2) at the filling pressure (P 1 ) is supplied by the filling pressure supply. The control piston (3) has a blind hole (5) in the direction of the longitudinal axis (13) of the control unit (2), a pressure relief valve (20) is arranged in the blind hole (5) and serves as a pilot control unit, the pilot control unit has The double-sided pressure relief piston (23) is arranged in the blind hole (5) and is slidable relative to the control piston (3) by the actuator (6), so that the displacement of the pressure relief piston (23) is carried out by the actuator (6). , the reduced filling pressure as the hydraulic set pressure (P 4 ) acts on the intermediate front surface (26) and distal front surface (27) of the pressure relief piston (23) and on the front surface (12) of the control piston (3). The control piston (3) can pass through the set pressure (P 4 ) generated by the sum of the pressure and the force of the actuator (6) moves within the control cylinder (4).

Description

Technical field [0001] The present invention relates to a control unit including a control piston slidably arranged in a control cylinder to be able to guide hydraulic fluid to a servo unit of a controlled displacement hydraulic unit under servo pressure. The servo pressure provided at the first outlet of the control unit is proportional to the sum of the internal force on the control unit and the operating force acting on the control unit. Therefore, the hydraulic fluid guided to the outlet is provided by the filling pressure supply device supplied to the inlet of the control unit. Background technique [0002] Such control units are known for example from DE 102008050835A1 and DE 10127907A1. [0003] Hydraulic units and their components (for example, static pressure pumps, static pressure motors, static pressure valves, or power cylinders) are usually operated in explosive atmospheres or areas with explosion risks. Therefore, the hydraulic unit and its components must be design...

AI Technical Summary

Problems solved by technology

However, this alternative reduces the level of energy used to generate control forces

Therefore, such explosion-proof design solutions usually have the following disadvantages: the limited energy is usually not enough to provide a high enough force for reliable, high-quality control / movement of the hydraulic unit

Therefore, the prior art solutions described above have the disadvantage of being relatively bulky and / or not intrinsically safe

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