A variable stroke high pressure pump is disclosed. The pump uses a wobble plate design with dynamically variable tilt to provide continuous adjustment of pump stroke length and output. Dynamically variable tilt is accomplished using a linearly actuated tilt thruster rotationally coupled to the drive shaft to maintain a selected tilt of the wobble plate through the rotation of the wobble plate.

An actuating piston for a hydrostatic adjustment installation includes at least one sealing and guiding unit which is insertable into a circumferential recess of an actuating piston. The circumferential recess is composed of two regions, and has the effect of improving the guiding and sealing of the actuating piston. The actuating piston is arranged in an adjustment installation.

A capacity control valve (1) for controlling a flow rate or pressure of a variable capacity compressor according to a valve opening degree of a valve section includes: a valve main body (10) having a first valve chamber (14), a second valve chamber (15) and a third valve chamber (16); a valve body (20) having an intermediate communication passage (26) for allowing communication between the first valve chamber and the third valve chamber, a first valve part (21a) arranged in the first valve chamber, a second valve part (21b) for opening and closing communication between the third valve chamber and the second valve chamber, and a third communication hole for allowing communication between the third valve chamber and the intermediate communication passage; a solenoid (30) having a first plunger connected to the valve body; and a second plunger (37) arranged between the solenoid and the valve body.

Variable displacement hydraulic unit comprising a displacement unit for setting/adjusting the position of an adjustment element in order to adjust the displacement volume of the hydraulic unit by means of an electronically driveable actuator. The actuator is electronically connected to an electronic control unit (ECU) and has a first electric conductive coil to position the adjustment element by the help of electro-magnetic forces. An electric energy harvesting device is located adjacent to the first coil of the actuator such that electric energy from power fluctuations in the first coil can be harvested inductively. The inductively harvested electric energy can be transmitted to an electric energy storage device.

An axial piston machine includes a housing, an actuating piston, and a closing screw. The housing includes a cylinder bore, a recess, and a fluid channel. An end of the bore open to an outside of the housing has an internal thread. The recess is located in a region of the internal thread, and is deeper than a thread depth of the internal thread so that a floor region of the recess is free from thread turns. The piston is linearly moveable in the cylinder bore, and is configured to adjust a displacement volume of the machine. The screw is screwed into the internal thread so as to form a closed chamber between the piston and the screw. The fluid channel opens into the floor region of the recess, and is fluidically connected to the cylinder chamber.

An electric displacement control system has a hydraulic variable displacement pump that operates in an open hydraulic circuit. A servo piston is disposed within a servo bore that is connected to the hydraulic variable displacement pump. Located in the servo bore is a control spool valve having an orifice that vents fluid pressure from the servo bore to a pump case. The flow rate of the system depends upon a fluid force between a feedback spring on a first side of the control spool valve and a solenoid actuator force on a second side of the control spool valve.

In a drive unit which has an axial piston pump and an electronic control unit, the axial piston pump is pivoted with a method in which pressure-reducing valves which act in opposition to one another are suddenly energized. Since in this respect no orifices are provided in the adjustment device, a so-called initiation jump of the excited current gives rise to a sudden reduction in the assigned actuating pressure or the actuating pressure difference formed therefrom. Then, a zero crossover jump of the excited current or of the excited currents is carried out in order to overcome the centering spring and therefore ensure a continuous zero crossover of the axial piston pump. Furthermore, a hydrostatic traction drive includes such a drive unit.

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.

A hydraulic transaxle comprises an axial piston hydraulic pump having a variable displacement, and a transaxle casing incorporating the hydraulic pump. The hydraulic pump includes a movable swash plate and a pair of trunnion shafts. The transaxle casing includes a pair of side walls, and includes a pair of casing holes each of which penetrates each of the side walls between an inside and an outside of the transaxle casing. The pair of trunnion shafts are passed through the respective casing holes. The swash plate is formed with a pair of swash plate holes in the respective side portions facing the respective side walls in the inside of the transaxle casing. Proximal end portions of the respective trunnion shafts are inserted into the respective swash plate holes. A distal end portion of one of the trunnion shafts projects from the corresponding casing hole to the outside of the transaxle casing.