Abstract: The invention relates to a method (3) for determining (33) a state characteristic value (28) of a electric device (4) controlled by a temporally variable control signal (17). The at least one state characteristic value (28) is determined using the frequency of the temporally variable control signal (17) and/or the switching characteristics of the temporally variable control signal (17).

Abstract: The invention relates to a method for actuating an electrically commutated fluid working machine (1), wherein the actuation of the electrically controllable valves (11) of the electrically commutated fluid working machine (1) is effected dependent on the fluid requirement and/or mechanical power requirements. In addition, on actuation of the electrically controlled valves (11) the electrical power required for actuating the electrically controllable valves is taken into account.

Abstract: Method for the load-dependent regulation of a hydrostatic drive (1), with a closed hydraulic fluid circuit comprising a first hydraulic motor (5) and, parallel to this, a second hydraulic motor (6), whereby both hydraulic motors (5 and 6) are capable of being powered by a hydraulic pump (3) via a high-pressure line (7) and a low-pressure line (8) and are mechanically coupled to each other via a transmission (70). The displacement of the first hydraulic motor (5) can be adjusted proportionally to an electrical signal of an electronic control system (50) by means of an electro-proportional control valve (10) and the displacement of the second hydraulic motor (6) can be adjusted by means of a pressure-proportional control valve (20) which is hydraulically connected to the high-pressure line (7) via a control pressure line (21). The pressure-proportional control valve can be activated by means of a control pressure which is dependent on the high pressure.

Abstract: The invention to a valve unit (1) for a synthetically commutated fluid working machine (51), comprising a valve body (19,57), a movably arranged valve unit (3) and a separate fluid flow influencing unit (13, 25, 31, 35, 46, 56). The fluid flow influencing unit (13, 25, 31, 35, 46, 56) comprises a fluid flow influencing means part (18) and an attachment means part (28, 34, 38) for mechanical connection with the valve body (19). The attachment means part (28, 34, 38) and the fluid flow influencing unit (18) are connected to each other by a connection means part (27, 30, 33, 40, 47). The circumferential extent of the attachment means part (28, 34, 38) is larger as compared to the circumferential extent of the connection means part (27, 30, 33, 40, 47).

Abstract: A power split transmission and a method of merging the power flows of the power split transmission are provided. A power input shaft drives a planetary gear set splitting the input power into a power flow over a variable power branch and into a power flow over a mechanical power branch. The power flows can be merged for driving a power take-off shaft. A reverser includes a first clutch, a second clutch, a first gear set and a second gear set. By engaging the first clutch and disengaging the second clutch the first gear set is driven, if an output shaft of the variable power branch and a mechanical transmission shaft are counter-rotating. By engaging the second clutch and the first clutch disengaging the second gear set is driven, if the output shaft of the variable power branch and the mechanical transmission shaft are co-rotating.

Abstract: Hydrostatic transmission and method for decelerating a hydrostatic transmission with a closed hydraulic fluid circuit, in which a hydraulic pump drivable by a drive engine and a hydraulic motor are arranged and connected fluidly to one another through two working lines. Alternately depending on the operational mode and on the conveying direction of the hydraulic pump, one working line is the low pressure line and the other one is the high pressure line. The hydraulic pump as well as the hydraulic motor are adjustable in their respective displacement volumes by means of a control unit. The hydraulic motor comprises a housing in which a hydrostatic drive mechanism having an inlet and an outlet is arranged. In a connecting line connecting the outlet and the inlet a pressure control valve is arranged, which can be flown through in direction to the inlet. The pressure control valve opens if the high pressure present at the outlet exceeds a predetermined pressure limit of the pressure relief valve.

Abstract: The invention relates to a method and a device for determining of at least one end position of a displacement element of an adjustable hydraulic machine, in particular of the axial piston type, shiftable or displaceable between two ends position a by means of a displacement unit between a first end position and a second end position. According to the invention the determination of having reached an end position of displacement takes place by means of a measurement circuit, whose electrical characteristics are changed jumpily when an end position is reached. This is done by connecting a partial branch of the measuring circuit with earth, when a moveable element comes into electric contact with a limit stop assigned to the corresponding end position.

Abstract: The invention relates to a charge pump system (190) comprising a hydrostatic charge pump (12) capable to generate a hydraulic flow rate to be fed into a closed circuit of a hydrostatic transmission, a planetary gear set (20), whose planet wheel carrier (22) is connected to an input shaft (11) of the charge pump (12), and whose sun wheel (21) is driveable by a driving shaft (3); and a charge pump motor (30) capable to drive the ring gear (23) of planetary gear set (20).

Abstract: The invention relates to a high-pressure hydraulic fluid screening element (1) for inserting into a hydraulic line or into a hydraulic connection of a hydraulic device, having an annular main body (2), which is aligned with respect to its axis of rotation (9) in a longitudinal direction (5). The outside diameter of the main body (2) is greater than its axial length. The inner cross section of the main body (2) is covered over by a screening region (3), which is provided with a multiplicity of apertures (4). In this case, the main body (2) and the screening region (3) are produced integrally by the powder injection-molding process.

Abstract: The invention relates to a displacement unit (1) of a hydraulic machine, for which the hysteresis is reduced. For this purpose, in the control spool (3) and/or at the control spool (3) a mass body (16) and a spring (17) are arranged, which are excited to resonance vibrations. The vibrations are self-excited and sustained by a partial flow rate of the hydraulic fluid which is modulated periodically. The high frequent vibrations are transmitted over the spring (17) onto the associated control spool (3), thereby reducing the friction and hence the hysteresis.

Abstract: A hydraulic control system that uses system pressure information and a rescaled operator input to command valve spool area to control actuator speed. The system uses soft sealing and/or soft pressure compensation.

Abstract: A valve housing includes a cylindrical valve bore with a high pressure inlet, a low pressure inlet and a discharge outlet. A first flushing valve spool is arranged elastically pre-stressed within the valve bore for enabling a fluid connection between the low pressure inlet and the discharge outlet. A shuttle valve spool is arranged elastically pre-stressed within the valve bore for enabling the fluid connection between the low pressure inlet and the discharge outlet. The first flushing valve spool is moveable into an open position if the fluid pressure at the low pressure inlet exceeds a first threshold value, and the shuttle valve spool is moveable into an open position for connecting the low pressure inlet with the discharge outlet, if the pressure difference between the high pressure inlet and the low pressure inlet exceeds a second threshold value.

Abstract: A variable fluid flow hydraulic pump including one or more displacement bodies having a fixed volume chamber. Within this fixed volume chamber a piston cycles or reciprocates thus providing for the movement of fluid. Also present is a low pressure valve connecting said displacement chamber with the low pressure side. Additionally, a high pressure valve may be provided on the high pressure side. The low pressure valve is provided with an adjustable element or Fcontrol providing an opening force thereon and further providing a closing force, which periodically increases during the pumping stroke and decreases during the suction stroke of said piston reciprocating within the displacement body and further includes an element to supply fluid from the low pressure side to said fixed volume chamber of the displacement body while the pressure in the displacement chamber is less than that of the low pressure side.

Abstract: Method for deceleration of a hydrostatic transmission 3 driven by a drive motor 2 comprising a closed hydraulic fluid circuit, in which a hydraulic pump 4 coupled mechanically with the drive motor 2 and a hydraulic motor 5 are arranged. Two hydraulic lines 6, 7 connect the hydraulic pump 4 and the hydraulic motor 5 and constitute for the hydraulic motor 5 according to the drive direction of the hydrostatic transmission 3 a supply line 6 and a return line 7.

Abstract: Hydrostatic adjusting device of a hydraulic machine, the swept volume of which can be adjusted by way of a servo adjusting unit, having a control unit which has a control cylinder which has at least one inlet for pressurized hydraulic fluid, at least one servo connector for a connecting line to the servo adjusting unit, and at least one outlet to a hydraulic fluid collecting region. A control piston is arranged in the control cylinder, which control piston can be displaced by means of at least one control piston actuator and has control edges. In interaction with control edges which are configured in the control cylinder, the inlet or the outlet can be alternately connected hydraulically to the connecting line, whereby the pressure which prevails in the connecting line can be returned hydraulically via a control line to at least one end side of the control piston.

Abstract: The invention relates to a hydraulic axial piston machine (1) of dry case type of construction, whose case (2) is provided for connection to a gearing case (21) so as to form a fluid-tight overall case. The case (2) has openings (10) which permit the passage of leakage hydraulic fluid or of lubricant into the gearing case (21). By means of this design, splashing losses of the axial piston machine (1) are eliminated, and the leakage hydraulic fluid or the lubricant serve for the lubrication both of the axial piston machine (1) and of the gearing (20).