Device for controlling a hydraulic pump or a hydraulic motor

A device (10) for controlling a hydraulic pump (12), comprising

• a hydraulic fluid reservoir (18),
• a hydraulic pump (12) having one inlet (20) and one outlet (22), wherein
• the inlet (20) is connected to the hydraulic fluid reservoir (18) by means of a first low-pressure line (24),
• the outlet (22) is connected to a high-pressure line (26) to which a consumer (16) can be connected,
• an adjustment unit (27) interacting with the hydraulic pump (12) and with which the delivery volume of the hydraulic pump (12) can be changed, the adjustment unit (27) being arranged in a high-pressure secondary line (36) connected to the high-pressure line (26),
• a secondary low-pressure line (50) branching off from the high-pressure secondary line (36),
• a low-pressure seat valve (54) arranged in the secondary low-pressure line (50) and interacting with the adjustment unit,
• a sensor with which an actual value of at least one characteristic variable that can be influenced by the delivery volume of the hydraulic pump (12) and relates to the consumer (16) can be detected,
• an actuator (46) with which a target value of the characteristic variable can be specified, and
• a control device (42) which interacts with the sensor and the actuator (46) such that the low-pressure seat valve can be activated taking into account the actual value detected by the sensor and the target value specified by the actuator (46).

A device (72) for controlling a hydraulic motor (66), comprising

• a hydraulic fluid pressure reservoir (74),
• a hydraulic motor having one inlet (20) and one outlet (22), wherein
• the inlet (20) is connected to the hydraulic fluid pressure reservoir (74) by means of a high-pressure line (26),
• the outlet (22) is connected to a hydraulic fluid reservoir (18) by means of a return line (68),
• an adjustment unit (27) interacting with the hydraulic motor and with which the displacement volume to be absorbed by the hydraulic motor (66) can be changed,
• a high-pressure seat valve (40) arranged in the high-pressure secondary line (36) and interacting with the adjustment unit (27),
• a sensor (44) with which an actual value of at least one characteristic variable that can be influenced by the displacement volume to be absorbed by the hydraulic motor (66) can be detected,
• an actuator (46) with which a target value of the characteristic variable can be specified, and
• a control device (42) which interacts with the sensor and the actuator (46) such that the high-pressure seat valve (40) can be activated taking into account the actual value detected by the sensor and the target value specified by the actuator (46).

A device (72) for controlling a hydraulic motor (66), comprising

• a hydraulic fluid pressure reservoir (74),
• a hydraulic motor having one inlet (20) and one outlet (22), wherein
• the inlet (20) is connected to the hydraulic fluid pressure reservoir (74) by means of a high-pressure line (26),
• the outlet (22) is connected to a hydraulic fluid reservoir (18) by means of a return line (68),
• an adjustment unit (27) interacting with the hydraulic motor and with which the displacement volume to be absorbed by the hydraulic motor (66) can be changed, the adjustment unit (27) being arranged in a high-pressure secondary line (36) connected to the high-pressure line (26),
• a low-pressure seat valve (54) arranged in the secondary low-pressure line (50) and interacting with the adjustment unit,
• a sensor with which an actual value of at least one characteristic variable that can be influenced by the displacement volume to be absorbed by the hydraulic motor (66) can be detected,
• an actuator (46) with which a target value of the characteristic variable can be specified, and
• a control device (42) which interacts with the sensor and the actuator (46) such that the low-pressure seat valve (54) can be activated taking into account the actual value detected by the sensor and the target value specified by the actuator (46).