A method operates a thick-matter pump having a thick-matter delivery system and a hydraulic drive system. The thick-matter delivery system delivers thick matter with a variably settable delivery volumetric flow rate for driving the thick-matter delivery system. The hydraulic drive system has: a hydraulic circuit having a hydraulic fluid, a variably operable first drive pump, and a variably operable second drive pump. The first drive pump is designed for variable operation with at least one variably settable first pump parameter and the second drive pump is designed for variable operation, independent of the first pump parameter, with at least one variably settable second pump parameter for generating a variably settable overall drive volumetric flow rate of the hydraulic fluid in the hydraulic circuit. The method determines an overall-drive-volumetric-flow-rate target value for the overall drive volumetric flow rate, and determines a first parameter target value for the first pump parameter and a second parameter target value for the second pump parameter in a manner dependent on the determined overall-drive-volumetric-flow-rate target value. The first and second parameter target values differ from one another if the determined overall-drive-volumetric-flow-rate target value is in at least one overall-drive-volumetric-flow-rate-target-value range from a set of possible overall-drive-volumetric-flow-rate target values. The method delivers the thick matter with the delivery volumetric flow rate at a delivery-volumetric-flow-rate target value by generating the overall drive volumetric flow rate with the determined overall-drive-volumetric-flow-rate target value by setting the first pump parameter to the determined first parameter target value and the second pump parameter to the determined second parameter target value.

An axial piston pump having several pistons has a magnetic encoder (5), which is arranged on a swash plate, and a magnetic field sensor, which is arranged in such a way that it faces towards the magnetic encoder (5). The magnetic encoder (5) has at least two permanent magnets (2, 3) and a plate (4) which consists of a ferromagnetic material. The permanent magnets (2, 3) are arranged on the plate (4) in such a way that they each faces a magnetic pole towards the plate (4), and this pole is at least partially covered by the plate (4) in each case.

A hydraulic system for a work machine, which includes a first hydraulic pump to deliver operation fluid, a second hydraulic pump to deliver pilot fluid, a first hydraulic actuator configured to control flow rate of the operation fluid based on the pilot pressure applied to the pressure receivers, a manual operator configured to operate the first hydraulic actuator, having an operation lever to move toward both directions, operation valves to change pressure of the pilot fluid in accordance with movement of the operation lever, and a discharge fluid tube to drain the pilot fluid from the operation valves. The hydraulic system includes an actuating valve in the discharge fluid tube and configured to reduce pressure of the pilot fluid in the discharge fluid tube.

A hydraulic system for a work machine, which includes a first hydraulic pump to deliver operation fluid, a second hydraulic pump to deliver pilot fluid, a first hydraulic actuator configured to control flow rate of the operation fluid based on the pilot pressure applied to the pressure receivers, a manual operator configured to operate the first hydraulic actuator, having an operation lever to move toward both directions, operation valves to change pressure of the pilot fluid in accordance with movement of the operation lever, and a discharge fluid tube to drain the pilot fluid from the operation valves. The hydraulic system includes an actuating valve in the discharge fluid tube and configured to reduce pressure of the pilot fluid in the discharge fluid tube.

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.

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.

In accordance with at least one aspect of this disclosure, a variable displacement pump system can include, a variable displacement pump disposed in a main line and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump is disposed in the main line between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.

A vehicle having a pair of electric actuators for use with a pair of drive apparatuses is disclosed herein. For each actuator, an electric motor drives a reduction gear train to position a control shaft, the reduction gear train having a worm drive that motivates a spur gear reduction. The housing of the electric actuator features a motor chamber to accommodate the electric motor and is sealed by a cap having an electric connector.

A variable positive displacement pump actuator system for a variable positive displacement pump can include a supply line configured to provide a supply pressure, a main pump line configured to provide a pump pressure greater than the supply pressure from the variable positive displacement pump, and at least one electro-hydraulic servo valve (EHSV) in fluid communication with the supply line and the main pump line to receive the supply pressure and the pump pressure. The at least one electro-hydraulic servo valve can be configured to output a first regulated pressure and a second regulated pressure. The system can include a first control line in fluid communication with at least one of the at least one EHSV to receive the first controlled pressure, a second control line in fluid communication with at least one of the at least one EHSV to receive the second controlled pressure, a first hydraulic actuator configured to connect to and/or otherwise actuate a lever arm of the variable positive displacement pump, the first hydraulic actuator in fluid communication with the first control line and the supply line to receive the first control pressure and the supply pressure to control a position of the first hydraulic actuator, and a second hydraulic actuator configured to connect to and/or otherwise actuate the lever arm of the variable positive displacement pump, the second hydraulic actuator in fluid communication with the second control line and the supply line to receive the second control pressure and the supply pressure to control a position of the second hydraulic actuator.

The invention concerns a hydrostatic drive with a closed hydraulic fluid circuit comprising a hydraulic motor and a variable displacement pump. A feed pump feeds hydraulic fluid under pressure. A control device regulates pressure to a double-sided servo control unit comprising a control piston in a double-sided control cylinder so that the control piston can open a feed line for hydraulic fluid to one side while opening a discharge line on the other. The control device comprises an actuator at the cylinder by means of which force can be exerted onto the piston. A preload element exerts force onto the piston. The pressure generated by the variable displacement pump returns via a return line such that force is exerted in the direction of the piston, if inactive, the piston is maintained by the preload element and the pressure of the variable displacement pump.