Patent ID: 6082107
Filing Date: 2000-07-04
Classification: E02F,F04B,F16H

Abstract:
Hydraulic controller, for the control of the rotating mechanism of an excavator, havinga hydraulic drive circuit (2-4) with a hydraulic pump (2) and a hydraulic motor, and a first and a second working line (3,4) connecting the hydraulic pump (2) with the hydraulic motor,an adjustment arrangement (26) for adjusting a setting piston (28a), acting on the displacement volume of the hydraulic pump (2), arranged between two setting pressure chambers (26,27), in dependence upon the pressure difference between two control lines (20,21) and characterized in that,a respective separate brake valve (24;25) is associated with each connection between teach of the two setting pressure chambers (26;27) with a pressure fluid tank (10),each said respective brake valve, responsive to a disappearing pressure in the control lines (20,21), throttling a return flow of the pressure fluid out of the setting pressure chambers (26,27) into the fluid pressure tank (10),whereby each of the two brake valves (24;25) is controlled by means of a force difference between a setting force exercised by the control pressure in the control line (20,21) acted upon by the greater control pressure and a return force exercised by a return member (80;81) provided for each brake valve (24;25).