Control systems and feedback assemblies for hydraulic axial displacement machines, such as pumps and motors. The control systems and feedback assemblies can have enhanced adjustability. An angle sensor for sensing the angular position of a pivot arm can have a housing, and the housing can be angularly adjustable about the pivot axis relative to the pivot arm.

A hydraulic pressurizing medium supply assembly has an adjustable axial piston machine. An actuating cylinder is controlled by way of a pilot valve. The pilot valve is actuated by a control installation. The control installation, as input variables, has an actual pressure and/or an actual swivel angle of the adjustable axial piston machine. One or a plurality of the input variables are compared with a matching nominal value and a control value is emitted, or in each case a control value is emitted. The controlling of the input variables is part of a first closed-loop control circuit. An underlying second closed-loop control circuit has an input variable which is based on the control variable or the control variables and serves as a nominal variable. A further input variable of the second closed-loop control circuit is an actual delivery-volume adjustment rate of the axial piston machine.

A control arrangement controls a position of a swashplate in an axial piston pump between a no-stroke position and a maximum stroke position. The control arrangement includes a servo spool mounted for limited sliding movement in a compensator piston cylinder. A solenoid coil is configured to provide a coil force to move the servo spool. A compensator piston is mounted in the compensator piston cylinder in response to movement of the servo spool. A spring between the servo spool and the compensator piston provides a spring force in response to the coil force applied to the servo spool. The control arrangement defines a feedback system configured to maintain a balancing relationship between the spring and coil forces to enable infinite control of the swashplate position.

A hydraulic pressurizing medium supply assembly includes a hydro machine which has an adjustable swash plate. An angle of the swash plate is able to be adjusted by way of a pilot valve. The pilot valve is able to be adjusted by a control. When the pilot valve is actuated by a neutral current, a valve slide of the pilot valve assumes a central position in which the swash plate does not perform any movement. In order for the pilot valve to be controlled it is provided that the control emits a control variable. The control variable, at the outlet side of the control, is linked and adapted to a preliminary control variable for the neutral current, in order for the neutral current to be pre-controlled.

A hydraulic pressurizing medium supply assembly has an adjustable axial piston machine. An actuating cylinder is controlled by way of a pilot valve. The pilot valve is actuated by a control installation. The control installation, as input variables, has an actual pressure and/or an actual swivel angle of the adjustable axial piston machine. One or a plurality of the input variables are compared with a matching nominal value and a control value is emitted, or in each case a control value is emitted. The controlling of the input variables is part of a first closed-loop control circuit. An underlying second closed-loop control circuit has an input variable which is based on the control variable or the control variables and serves as a nominal variable. A further input variable of the second closed-loop control circuit is an actual delivery-volume adjustment rate of the axial piston machine.

The invention is directed to a swashplate angle sensor (10) for a variable displacement hydraulic unit (1). The hydraulic unit (1) comprising a housing (2), within which a swashplate (3) with a rod shaped feedback-link (12) fixedly attached to the swashplate (3) is arranged pivotable around a swashplate axis (7). The angle sensor (10) comprising a magnet (16) mounted rotatable on a magnet carrier (13), and a sensor (15) for sensing the orientation of the magnet (16). The magnet carrier (13) is located in a control block (14) attached to the housing (2) and is located parallel to the feedback-link (12). The magnet carrier (13) is rotatable around a sensor axis (18) being parallel to the swashplate axis (7). A linkage spring (11) provides a connection between the feedback-link (12) and the magnet carrier (13) such that a pivoting of the swashplate (3) with the feedback-link (12) causes a rotation of the magnet carrier (13).

Control systems and feedback assemblies for hydraulic axial displacement machines, such as pumps and motors. The control systems and feedback assemblies can have enhanced adjustability.

A control arrangement controls a position of a swashplate in an axial piston pump between a no-stroke position and a maximum stroke position. The control arrangement includes a servo spool mounted for limited sliding movement in a compensator piston cylinder. A solenoid coil is configured to provide a coil force to move the servo spool. A compensator piston is mounted in the compensator piston cylinder in response to movement of the servo spool. A spring between the servo spool and the compensator piston provides a spring force in response to the coil force applied to the servo spool. The control arrangement defines a feedback system configured to maintain a balancing relationship between the spring and coil forces to enable infinite control of the swashplate position.

Control system and control method of a variable displacement hydraulic pump wherein the system includes a detection sensor for detection of the actually set displacement and a control unit for current control of a couple of solenoids controlling displacement increase and decrease.

The invention is directed to a swashplate angle sensor (10) for a variable displacement hydraulic unit (1). The hydraulic unit (1) comprising a housing (2), within which a swashplate (3) with a rod shaped feedback-link (12) fixedly attached to the swashplate (3) is arranged pivotable around a swashplate axis (7). The angle sensor (10) comprising a magnet (16) mounted rotatable on a magnet carrier (13), and a sensor (15) for sensing the orientation of the magnet (16). The magnet carrier (13) is located in a control block (14) attached to the housing (2) and is located parallel to the feedback-link (12). The magnet carrier (13) is rotatable around a sensor axis (18) being parallel to the swashplate axis (7). A linkage spring (11) provides a connection between the feedback-link (12) and the magnet carrier (13) such that a pivoting of the swashplate (3) with the feedback-link (12) causes a rotation of the magnet carrier (13).