Abstract: The invention relates to a method and a circuit arrangement for controlling and regulating the supply of pressure medium to at least two hydraulic consumers, which are assigned in each case a directional valve for setting the flow and a setpoint signal source, by means of a pump with a variable displacement, which can be regulated by means of a displacement controller. The pump displacement is regulated according to the flow required by the setpoint signals. The individual load pressure of the consumers and of the consumer having the highest load pressure are determined. The directional valve of the highest loaded consumer is controlled to a valve-spool position y1, with y1=K·y1,max=const., which lies by a factor K, with 0<K<1, below the valve-spool position y1,max representing the maximum opening of the directional valve.

Abstract: The invention relates to a hydraulic circuit arrangement for setting the delivery volume of a pump, with an electrically activatable control-valve unit, by means of which, alternately, an active side of a servo system can be acted upon with pressure and, at the same time, its passive side can be relieved to the tank, and with a device for pressure limiting pressure regulation, which comprises pressure limiting valves, by means of which the working lines of the pump can be connected to the servo lines. To reduce the servo pressure load and improve the reaction time, check valves which shut off in the direction of the servo system are provided, by means of which the two servo sides can be connected in each case to the charge pressure via a relief line. Moreover, the device for Pressure limiting pressure regulation comprises an orifice which can be positioned in a line leading to the passive servo side. The invention relates, furthermore, to a method for pressure.

Abstract: An axle driving apparatus which has a housing and a hydrostatic transmission therein separate from the housing with fluid conduits in a center section connected to hydrostatic rotatable cylinder blocks operatively connected to axle shafts, the improvement involving check valves associated with the fluid conducting conduits and including check valve balls to affect fluid flow through the conduits and being positioned to move in a vertical path in a direction at right angles to the axes of the axle shafts, and a movable bypass arm mounted in the housing and movable to open or close the fluid conduits.

Abstract: A method of adjusting the applied force for controlling the material removal rate on a work piece. A machining device having a load providing device, a force transducer and a force applying device wherein the force-applying device provides a load to the work piece to remove material. The force applied to the work piece by the load providing device and the position of the load providing device are sensed and transmitted to a master controller that adjusts the force applied to the work piece based upon these readings.

Abstract: When employing synthetically commutated hydraulic pumps (1), a time delay between a change in fluid flow demand (15) and the resulting fluid flow output (13) can be observed. It is suggested to use a time evolvement function, taking into account the time evolvement of the fluid flow demand and/or the time evolvement of the pumping strokes, to modify the actuation of the electrically commutated valves.

Abstract: The invention concerns a hydraulic steering (1) with a supply connection arrangement (P, T), a steering motor (2) and a steering unit (3) between the supply connection arrangement and the steering motor (2), the steering unit (3) having a directional section (4) and a measuring section (5), a steering valve (9) being arranged in parallel to the steering unit (3). With such a steering, it is endeavoured to achieve the best possible safety. For this purpose, it is ensured that for each steering direction the directional section (4) comprises a first outlet (A1L, A1R), which is connected to the steering motor (2) by means of a first pipe (23, 24), and a second outlet (A2L, A2R), which is connected to the steering motor (2) by means of a second pipe (25, 26), the first outlet (A1L, A1R) being, in the neutral position of the directional section (4), connected to the measuring section (5), and the first pipe (23, 24) being interruptible by means of a valve arrangement (27, 27a).

Abstract: In open-circuit hydraulic systems (1), the cross-sections of the supply lines (6) and input valves of the hydraulic pump (3) have to be large, so that sufficient flow flux can be provided. This hinders a reduction of the size of the pump and the whole hydraulic system. It is suggested that the supply flow (7) of a hydraulic pump (3) is charged by a second, charging pump (2), to a mid-pressure level (7). The cross-sections of the supply flow areas can thus be decreased.

Abstract: The invention relates to a hydrostatic bent axis power unit having a synchronizing joint for the angularly adjustable drive-connection of a cylinder block, which has pistons, to a driveshaft. The synchronizing joint has a shank which is rotatable about its longitudinal axis and thereby defines the joint axis, on the ends of which shank at the drive input and drive output side are provided in each case laterally projecting roller carriers which define a roller axis, which is aligned approximately at right angles to the joint axis, for rollers which are provided on the roller carriers, and against the two ends of which shank bears in each case one connecting pin which is aligned in the direction approximately of the joint axis. In each case one securing element is provided at the two ends of the shank, which securing element both holds the connecting pin in the region of the joint axis in contact against the shank and also prevents the rollers from sliding off the roller carriers.

Abstract: A method of operating a vehicle with a hydrostatic circuit. The method includes providing a hydrostatic circuit having first and second hydraulic kits that are fluidly connected to one another by first and second fluid lines. A by-pass valve is placed between the first and second hydraulic lines and is controlled in order to actuate the by-pass valve when certain predetermined conditions are present in order to relieve pressure within the hydrostatic circuit.

Abstract: An operating system for an electric motor associated with a hydraulic pump for moving a load and method of operating the same. The operating system includes a power source that is electrically connected to the electric motor wherein a capacitor charge and discharge circuit is used in association with a capacitor in order to store energy within the capacitor as the operating system is in use.

Abstract: An axial piston hydraulic machine having a housing with a cylinder block with reciprocating pistons disposed therein. The reciprocating pistons are rotatably connected to a swashplate at a first end of the swashplate. At a second end of a swashplate support balls are received and engage the housing. The support balls are located radially from the plurality of reciprocating pistons such that the distance between the axis of rotation of an input shaft and a piston axis of the plurality of pistons is significantly less than the radial distance between the axis of rotation of the shaft and the center points of the support balls, and wherein the pivot axis passing through the center points of the support balls lies in or near the plane passing through the piston/slipper ball joints.

Abstract: A relief valve for a hydraulic machine that combines a poppet valve assembly and a pilot valve assembly together using a connector pin wherein internal fluid passageways within the poppet and pilot spools provide a fluid flow path between the inlet of the valve and a cavity disposed between the poppet and pilot. As a result of the internal passageways fluid is metered to the interior cavity to provide additional control and stability within the relief valve.

Abstract: The invention concerns a method for controlling a raising drive, the raising process occurring by means of pressure activation of at least one lift cylinder and the lowering process occurring by means of relieving, and a control of the lowering speed occurring by means of a variable flow resistance. In order to achieve a load-independent lowering speed, the flow resistance is determined in dependence of at least one load signal.

Abstract: The invention provides a steering system for a vehicle, a ship etc. The steering system has a steering handle for the operator of the vehicle, a set of signal processors, a sensor which determines a position of the steered element of the vehicle, and a controller which moves the steered element. The steered element could e.g. be the front wheels of a car. The signal processors are adapted to determine an error between the desired position of the steered element and an actual position of the steered element. In order to make the steering system more fault tolerant, the error signal is amplified based on the speed by which the steering handle is moved, and an error in the sensor therefore becomes less critical. The invention further provides a steering method, a steering control unit and a vehicle provided with a steering system of the mentioned kind.

Abstract: A method of cooling a radiator in an internal combustion engine wherein a plurality of fan assemblies is provided. Specifically, each fan assembly has a housing with an interior containing a fan blade and an exterior having six sides to form a hexagonal perimeter. The fan assemblies are then arranged side by side to form a cluster of fan assemblies in order to maximize the amount of fan assemblies that may be provided on an enclosure. The cluster of fan assemblies is then placed adjacent to a radiator to control the air flow over the radiator in order to cool the engine.

Abstract: An axial piston hydraulic device. The device has a housing that uses a servo piston in order to control the displacement of a swashplate within the device. By using a servo member disposed within a cavity of an end cap on the housing the axial piston hydraulic device is able to provide three operating positions depending on the angle of the swashplate.

Abstract: The invention provides a method of calibrating a steering system for a vehicle, e.g. an off-highway machinery, to allow automatic steering based on input from a position or tracking system, e.g. based on a Global Positioning System (GPS). At least two records, each comprising a position value and a curvature value are established. The position value represents a position of the steered element, e.g. a position of a steered wheel of the vehicle, and the curvature value could e.g. be expressed as a radius of a curve followed by the vehicle with that position of the steered element. The curvature value is determined by the positioning system during movement of the vehicle. Due to the records, it is easy to calibrate or recalibrate the system and the invention is therefore applicable e.g. in connection with manufacturing of vehicles in small batch numbers, e.g. for one of a kind production or for retrofitting of steering components to existing vehicles.

Abstract: The invention relates to a hydrostatic transmission having two bent axis- or swashplate-type axial piston units which are operated alternately as a pump and as a motor, with the two axial piston units being adjustable together with a pivotable dual yoke or by means of a pivotable dual swashplate. In order to minimize the dead volumes of the two axial piston units, the rotational axes of the two axial piston power units are offset with respect to the pivot axis of the dual yoke or of the swashplate by a magnitude such that, at all pivot angles, the power unit pistons, at dead centre, are located in the direct vicinity of the bore end of the cylinder block.

Abstract: A method for programming computer code at a remote platform having a local computer. A home device sends a computer code to the local computer via wireless transmission wherein the computer code is stored within an alternate area of a flash memory. Once a complete copy of the computer code is recognized at the local computer the integrity of the computer code is checked and if proper, a new boot address is assigned at the local computer. At this time the local computer is rebooted such that when the computer restarts the alternate computer code is used thus effectively updating the computer software.

Abstract: The invention concerns a hydraulic valve arrangement (1) having at least two working connections (A, B), a check valve (5, 6) being allocated to each working connection (A, B), and a pressure relief valve (7, 8) being allocated to each check valve (5, 6), each pressure relief valve (7, 8) being connected to a control pressure passage (17, 18). The valve arrangement shall ensure a reliable, pressure-less lowering, also in connection with single-actuated consumers, and further enable a pressure-less float position. For this purpose, the check valves (5, 6) can be opened by means of tappets (20, 21), whose sides facing away from the check valves (5, 6) are ending in a pressure chamber (22), which is connected to the control pressure passage (17, 18) of one of the pressure relief valves (7, 8).