Abstract: Elastically deformable seal of an electrical control unit of a hydraulic machine. The seal has a pot-like shape with a diaphragm, which is in the form of a pot base, and also pot inner faces, pot edge faces and pot outer faces. In this case, the pot inner faces have first sealing faces, the pot edge faces have abutment faces and the pot outer faces have second sealing faces. The first sealing faces and the abutment faces are formed in such a way that they deform under pressure loading such that the second sealing faces arch out from the pot outer faces.

Abstract: The invention concerns a hydraulic valve arrangement (1) with a control valve module (2) comprising a supply connection arrangement with a high-pressure connection (P) and a low-pressure connection (T) and a working connection arrangement with two working connections (A, B) as well as a control valve (3) between the supply connection arrangement and the working connection arrangement. It is endeavored to improve the control behavior of the valve arrangement. For this purpose. it is ensured that the control valve module (2) has a return compensation valve (15, 16) between the control valve (3) and at least one working connection (A, B).

Abstract: AC inverters that are electrically connected to a direct current source to convert the direct current source such that the transistor power module of an inverter can power a plurality of AC motors wherein the motors can be located remote from the inverters or within the inverter housings.

Abstract: A system for operating a hydromechanical transmission having a movable input member that transmits a signal to a control unit that uses predefined logic to determine if a hydrostatic transmission should be in a first low speed mode that uses displacement control or if it should be in a second high speed mode that uses a power, torque, or speed control scheme.

Abstract: An improved rotary spool control system for a closed hydrostatic circuit and method to use the same. The control spool utilizes metering of the spool notches and specifically the metering of the servo drain notch wherein the drain notch is of irregular cross sectional shape. Because of the metering and irregular cross sectional shape, this spool is able to provide an aggressive response while still having smooth linear control. The method of creating the feedback control includes displacing pressurized fluid through the hydrostatic circuit rotating the control spool to create an error signal removing the error signal with a control sleeve and metering the servo piston drain with the irregularly shaped metering porting notch.

Abstract: A method of measuring vibration on an operational device. The method includes providing an operational device with a control unit and a vibration sensor comprised of a three axis accelerometer, a digital signal processor, and a communications transceiver. The digital signal processor takes the raw vibration data for each axis of the three axis accelerometer and applies a weighting function to the vibration data for each individual axis. Then stress level data associated with the vehicle operator is used to calculate the instantaneous contributions of the filtered data to the stress level data of the operator to determine instantaneous stress level data that has accumulated over a fixed time interval. After the fixed time interval, the digital signal processor calculates an increase of the stress level of the operator during the time interval to create stress data that is transmitted through a communications transceiver for display.

Abstract: A joystick (1) having a yoke pivotally secured to an upper support (28) and a lever (16) pivotally secured to a lower support. The yoke has a latching portion that engages a cam roller (14) on the lever to push the lever downward. Supported on the lever is an armature (24) positioned in spaced relation to a solenoid (26). The solenoid is energized based on the movement of the yoke.

Abstract: An engine management system and a method of operating the same within a vehicle. The system uses a plurality of software modules one of which communicates with the vehicle engine to communicate information and additionally communicates with at least one other software module that provides information regarding auxiliary device operations and parameters such that the first software module produces an input torque curve signal for the vehicle engine. Additionally, secondary software modules are able to provide reduced power requirements signals to a plurality of auxiliary devices in order to ensure optimum fuel economy and noise reduction.

Abstract: The invention provides a fluid controller for controlling a machine, e.g. for steering a vehicle. The controller comprises a housing defining an inlet port connected to the source and an outlet port connected to the pressure operated device. The flow rate is controlled by movement of a valve member within the housing, and a processor provides a reference which is indicative of a desired position of the valve member relative to the housing. The fluid controller comprises a fault detection system based on an observer. The observer calculates a theoretically correct position of the valve member relative to the housing for a given reference, and compares this position to an obtained position of the valve member relative to the housing. The difference between the positions is compared with a threshold value. In order to dynamically change the sensitivity of the system, the threshold value is scaled based on a gradient of the reference.

Abstract: The invention relates to a hydrostatic mechanical traction gearbox having a continuously variable hydrostatic drive in which the hydrostatic drive has a hydrostatic pump driven by an internal combustion engine and a hydraulic motor driven by the pump, the pump and the hydraulic motor are positively coupled in an adjustable fashion by means of a single common pivoting part in such a way that the pump can be pivoted between a minimum angle and a maximum angle while at the same time the motor pivots synchronously from a maximum pivot angle to a minimum angle. The pump is configured for a single delivery direction of the volume flow. A mechanical range change gearbox is connected downstream, said gearbox having a plurality of gear shifting stages which can be shifted by means of a clutch.

Abstract: The invention relates to a hydraulic module for hydrostatic mechanical gearboxes having two swashplates or oblique axis drive units which are integrated in the hydraulic module. The swashplate drive units are mounted in a common housing with parallel drive shafts and each have a rotating cylinder block with expellers which can move therein and which are supported in a sliding fashion on a double swashplate whose pivot angle is adjustable by means of a servo system. The double swashplate is designed to carry out positively coupled common adjustment of the volume flow of the two drive units and is equipped with bearing faces for the expellers of the respective drive units, said bearing faces having different angles of inclination relative to the respective drive shaft. The oblique axis drive units each have a cylinder block with expellers which can move therein and which are each pivotably mounted on the coaxial shafts.

Abstract: A positive displacement piston unit is provided that utilizes a magnetorheological (MR) or electrorheological (ER) fluid as the transmission fluid. Each cylinder of the invention has an intake port connected to the suction port of the hydrostatic pump and an output port connected to the pressure port. Flow of the transmission fluid through the cylinder is controlled by an electromagnet or electrode located in close proximity to the intake and output ports of the cylinder. By energizing the electromagnet or electrode, the viscosity of the transmission fluid can be increased such that the portion of the fluid immediately near the electromagnet or electrode substantially solidifies. The solidified portion of the transmission fluid disables fluid through the particular passage, thereby restricting flow of the transmission fluid to the cylinder. As such, the present invention does not require the use of mechanical cylinder valves to control the flow of the transmission fluid.

Abstract: An axial piston machine having a swashplate or an oblique axis which can be adjusted by means of servopistons and has a valve segment and an adjustment unit for the electrically proportional adjustment of the volumetric displacement. The adjustment unit comprises proportional magnets which can be activated electrically, and a control piston for controlling the oil pressure which moves the servopistons. The proportional magnets act on the control piston along a common tappet axis, a feedback device for feeding back the current swashplate or oblique-axis valve-segment position to the control piston being provided. The feedback device comprises spring levers 6, 6? which can pivot about an axis, the spring levers 6, 6? each being mounted on the pivot axis 5 with a bearing shell 15, which are each composed of two component shells which support the spring lever 6, 6? at separate locations on the pivot axis 5, and which each essentially enclose a half-space about the pivot axis 5.

Abstract: A charge pump is provided with two independent outlets that can satisfy the pressure requirements of both a charge circuit and an auxiliary circuit. Preferably, the charge pump is a multiple roller vane pump that has at least one inlet and two outlets independent of each other. The first outlet is in fluid communication with a charge circuit, and the second outlet is in fluid communication with an auxiliary circuit. Because the two outlets are independent of each other, the roller vane pump is able to satisfy the pressure requirements of both the charge and auxiliary circuits. Preferably, the two outlets are diametrically opposed to each other, thereby reducing the load on the driveshaft. Additionally, the roller vane pump may include a second inlet independent of the first.

Abstract: AC inverters that are electrically connected to a direct current source to convert the direct current source such that the transistor power module of an inverter can power a plurality of AC motors wherein the motors can be located remote from the inverters or within the inverter housings.

Abstract: The invention concerns a hydraulic steering with a steering motor arrangement having at least one steering motor, and with at least two steering circuits, each having a steering valve that interrupts a path from a pressure supply to the steering motor arrangement in the neutral position and releases a path from the pressure supply to the steering motor arrangement on a movement out of the neutral position. It is endeavoured to simplify the embodiment of such a steering. For this purpose, the steering valve (5a, 5b) has two end positions, one on each side of the neutral position, in which positions a path from the pressure supply (15, 21) to the steering motor arrangement (2) is interrupted.

Abstract: The invention concerns a hydraulic steering with a steering motor arrangement, a steering valve arrangement and a pressure supply comprising a first pump and a second pump. It is endeavoured to perform a change between the supplies by the pumps as unperceived as possible. For this purpose, the steering valve arrangement (4) is connected to the first pump (6) through a valve (8) with pressure compensation function and to the second pump (19) through a compensation valve (26).

Abstract: A holddown pin mechanism for hydraulic power units is a ball guide with a cylindrical flat base having a central opening, a plurality of spaced elongated holddown pins have one end rigidly secured to one side of said ball guide. The pins extend outwardly at right angles from the side of said washer to which they are secured. The holddown pin mechanism is placed in a hydraulic cylinder block having a center bore, with the pins extending into holes in the block. A flat washer on a shaft extending through the block engages the free ends of the pins.

Abstract: A steering system for a work vehicle adjusts the steering ratio in response to changes in the speed of the work vehicle.