| 摘要 |
An electrohydraulic transmission having at least one hydraulic functional member or hydraulic motor, has a hydraulic pump with a variable displacement, from whose outlet the functional member is supplied via a throttle of variable diameter and a directional control valve. A single pressure transducer is provided for each functional member, in order to produce an electrical pressure signal which indicates the pressure behind the variable throttle position. The pressure signal is fed to a modulation circuit which generates a pulse-width modulated control signal having a duty cycle which varies as a function of the pressure signal and a fixed reference signal. With the aid of this modulated control signal, the pressure at the adjusting device for varying the displacement of the hydraulic pump is controlled so that this then operates at a predetermined no-load pressure, when the load is switched off, and when the load is switched on operates such that a predetermined pressure difference is maintained between the outlet pressure of the hydraulic pump and the pressure behind the variable throttle position. |
