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: A vane-type fluid displacement unit having a housing, a drive shaft extending through the housing, a rotor secured to the drive shaft and disposed within the housing, the rotor having at least one non-smooth top or bottom surface, and at least one vane secured to the rotor.

Abstract: The invention relates to an axial piston engine with a filling pump integrated in a receiving bore of the axial piston engine, which filling pump comprises a gerotor set with an externally toothed inner ring and an internally toothed outer ring and also an inner thrust plate and an outer thrust plate. The two thrust plates enclose the gerotor set between them and, on their surfaces facing away from the gerotor set, are in each case supported via a pressure field seal, which surrounds the pressure field regions formed in the thrust plates, in such a way on the housing walls axially enclosing the filling pump that lateral play in the form of axial mobility of the filling pump is guaranteed.

Abstract: A hydraulic unit that uses first and second support structures to eliminate the use of webs within an arcuate inlet and outlet of a valve plate. Specifically, a valve plate body extends between an inner and outer diameter wherein the outer diameter in a first position is placed in close proximity to a first support structure and the inner diameter is placed in close proximity to a second support structure. Thus, stress of hydraulic fluid flowing through the arcuate inlet or outlet deflects the inner and outer diameters causing them to engage the first and second support structures such that stress is passed to the first and second support structures and the valve plate is stiffened.

Abstract: A joystick device is provided that is in electronic communication with a remotely located main electronic controller used to control heavy machinery and the like. The joystick device includes a base assembly having a first microprocessor in electronic communication with the main electronic controller. The joystick device also includes a grip assembly pivotally connected to the base assembly. The grip assembly includes a plurality of input buttons and a second microprocessor in electronic communication with the first microprocessor. The joystick device further includes sensing elements that detect movement of the joystick device.

Abstract: A gasket for a hydraulic housing and a method of manufacturing the same. The gasket is made by taking a metal body having a first and second side and coating the first and second side with rubber. An area of the rubber is then burned off by a laser and then in that area the laser is used to create a plurality of openings that act to filter hydraulic fluid that flows through the gasket.

Abstract: A relief valve assembly. The relief valve assembly has a housing that houses a sleeve element that surrounds a spool that has a spring guide disposed therein and is biased away from the spool by a spring. A fluid flow path is created from a valve exit of the assembly through the sleeve and spool via a series of openings, grooves and orifices in at least one position of the relief valve assembly. The fluid flow path acts to reduce pressure rise rate.

Abstract: A valve assembly for a hydraulic device. The valve assembly has a valve seat within a valve passageway used in combination with a spool. The spool has a first section wherein a flexible element is disposed within a cavity of the first section such that in a first position the spool and specifically the flexible element engages the valve seat to provide zero leakage from the valve passageway into a tank passageway. Additionally, the spool is designed to have an additional section at a second end to provide equal sealing areas at both the first and second ends of the spool to balance the forces within the valve passageway.

Abstract: An arrangement for filtering a hydraulic fluid having a bypass line connecting the feed channel to the discharge channel where the bypass line is opened by a pressure switching valve when a pressure change is caused by the contamination of the filter element.

Abstract: A method of yielding the average current in a PWM driven coil for an electrohydraulic valve. The method includes transmitting a feedback signal into a Finite Impulse Response filter to take multiple signal samples in order to calculate and average value of current within one cycle. This average value is transmitted to an algorithm that generates a pulse width signal that drives the coil of the electrohydraulic valve in the next system cycle.

Abstract: A method of calibrating a valid operating range. The method includes loading a default calibration limit and then monitoring an input for new calibration limits provided by an input device. An algorithm then detects if the new calibration limits provide a fault and if not the algorithm rescales the output based upon the new calibration limits to increase the valid operating range.

Abstract: The invention relates to a method for regulating a hydrostatic drive system which has at least one pump which is driven by an internal combustion engine and at least one hydraulic motor which is driven by the pump, and comprises the method steps: determining the volume flow rate flowing through the hydraulic motor; determining a first adjustment nominal value for the hydraulic motor as a function of the previously determined volume flow rate rate; determining a second adjustment nominal value by modifying the first adjustment nominal value by a correction value which is determined as a function of the nominal/actual value deviation of the internal combustion engine rotational speed by means of a vehicle-specific characteristic curve which incorporates the different power profiles for traction and overrun operation, respectively, of the internal combustion engine, with the hydraulic motor being adjusted in such a way that a substantially constant pressure level is generated at the maximum power level of the in

Abstract: A hydromechanical transmission having a self actuating clutch assembly. The self-actuating clutch assembly comprises a first and second gear clutching elements and a shaft clutching element that engages a shaft. The shaft clutching element is a cone clutch that is actuated by a ball element that is biased towards the shaft clutching element by a spring element that is disposed through the shaft.

Abstract: A hydromechanical transmission having at least first and second three element planetaries directly connected to one another. The first and second three element planetaries work in conjunction with a hydrostatic transmission and a plurality of clutches in order to provide at least first and second forward operating modes having continuous ratios.

Abstract: A transmission control system for a vehicle. The control system has a control unit that receives a plurality of inputs from the vehicle and the vehicle operator. Then based upon these inputs the control unit sends a plurality of output signals to an engine, an input clutch, and a transmission in order to selectively operate each of these components to actuate the axle and wheels of a vehicle.

Abstract: A method of operating a transmission of a vehicle. The method includes determining an open loop ratio percentage from an engine RPM input signal and a brake input signal using a first algorithm. Determining a closed loop ratio percentage from the engine RPM input signal, a vehicle RPM input signal and a throttle input signal using a second algorithm. Summing the open loop percentage and closed loop ratio percentage to calculate a ratio command percentage that is used to sum with a swashplate input to actuate a swashplate positioner and operate the transmission.

Abstract: A hydrostatic variable displacement unit is provided having a swash plate which serves to adjust the stroke of displacement pistons in a cylinder block and can be pivoted in its angular position by means of a servo system, the servo system having at least one servo piston with two servo-piston end surfaces which are in each case assigned a servo cylinder and a servo-piston rear surface, and the servo cylinders, by means of the assigned servo-piston end surfaces, in each case bounding a servo-cylinder pressure space. The servo piston is acted upon by a spring arrangement having at least one spring arranged outside the servo-cylinder pressure space and clamped between two spring plates. The two spring plates are acted upon by the springs in the direction of a stop of the particular servo cylinder that is situated on its side such that in the neutral position, the spring plates bear against the servo-piston rear surfaces and against the stop of the particular servo cylinder.