Elektrohydraulisches Servoventil

摘要

A working piston in a main cylinder and a pilot piston in an ancillary cylinder are linked to opposite ends of a two-arm lever having a floating fulcrum on the shaft of a torque motor whose energization, resulting in a shift of the pilot piston, gives rise to a fluid flow displacing the working piston in the same sense, thereby transmitting to the lever a reaction force which restores the pilot piston to its normal position. The coupling between the lever and the working piston includes a pair of coil springs whose adjustable pressure determines the restoring force and therefore the ratio of input signal to flow rate. The position of the working piston is stabilized by balanced fluid pressures acting upon opposite lands thereof in the normal position of the pilot piston.