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 for achieving high quality shifts with one hydraulic unit near zero displacement when using dog clutches. This method includes selecting the proper displacement and vocation (whether the hydrostatic unit works as a pump or motor) of a low displacement hydraulic unit during the shift, selecting the appropriate speed differential between the clutch elements, selecting the proper vehicle speed at which to make the shift, and sequencing the displacement changes of the hydraulic units with a controller in order to achieve the desired shift conditions.

Abstract: The invention concerns a valve arrangement for controlling a hydraulic drive having a first working connection (A) and a second working connection (B), and being connectable with or separable from a pressure source (P), the supply and the outflow of the hydraulic drive being separately controllable. It is endeavoured to improve the energetic efficiency of the valve arrangement. For this purpose, the first working connection (A) is connected with a first control valve and the second working connection (B) is connected with a second control valve, the first and the second control valves being connected with each other and with a third control valve, which is connected with a tank.

Abstract: The invention concerns a brake valve arrangement of a vehicle having a trailer coupling and at least one controllable hydraulic consumer, with a brake valve (27). It is endeavoured to provide a similar embodiment of a vehicle with such a brake valve arrangement. For this purpose, the brake valve (27) is combined with at least one control valve (11, 12) controlling the hydraulic consumer into forming a valve block (10) having several valve modules.

Abstract: The invention concerns a hydraulic control (1) with a supply connection arrangement (7) having a high-pressure connection (P) and a low-pressure connection (T), a working connection arrangement having two working connections (A, B) connectable with a consumer, a control valve (8) with a valve element (9) between the supply connection arrangement and the working connection arrangement and a compensation valve (11), which is located between the high-pressure connection (P) and the control valve (8) and is acted upon in the closing direction by a pressure between the compensation valve (11) and the control valve (8). It is endeavoured to ensure the most favourable energy consumption possible. For this purpose, in the opening direction the compensation valve (11) is acted upon by a pressure of a selection device (29, 30, 30?, 38), which optionally supplies the compensation valve (11) with a pressure control pressure or a flow control pressure.

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 hydraulic valve arrangement with a first and a second working connection, both working connections being connectable with a hydraulic consumer, a supply connection having a pressure connection and a tank connection, a first valve, which closes the pressure connection or connects it in a controlled manner with the first working connection or the second working connection, a second valve, which closes the tank connection or connects it in a controlled manner with the first or the second working connection, and a control device, which controls the first valve and the second valve. It is endeavored to enable a simple manner of exact controlling the consumer. For this purpose, at least one valve is provided with an opening degree sensor, which is connected with the control device, the control device controlling the valve arrangement in dependence of the signal from the opening degree sensor and a specified signal.

Abstract: The invention concerns a hydraulic steering arrangement (1) with a supply connection arrangement having at least a high-pressure connection (P) and a low-pressure connection (T), a working connection arrangement having at least two working connections (L, R), a steering unit (7), which can be activated by a steering transducer (2), the steering unit having a first load-sensing connection (LS1), and a steering valve (8) having a second load-sensing connection (LS2), the steering unit (7) and the steering valve (8) being arranged in parallel with each other between the supply connection arrangement and the working connection arrangement. It is endeavoured to ensure a good steering behaviour.

Abstract: In a power unit comprising an engine (13) and an HST (24) which are formed into an integral body, a lubricating oil for use in the engine and an operating oil of the HST (24) are commonized. After being cooled, the common oil is fed from the side of the engine (13) to the HST (24). Such arrangement suppresses the drop in viscosity of the common oil and prevents the drop in efficiency and the occurrence of seizing on the side of the HST (24).

Abstract: A roller bearing assembly for a variable displacement hydrostatic unit. The roller bearing has an inner race and an outer race with a cage therebetween that holds a plurality of rollable elements. A link is mounted to the inner and outer race such that the link is able to limit the arcuate movement of the cage element.

Abstract: A circuit that provides for a high side NFET gate driver that uses a circuit using only common capacitors, diodes, resistors, and transistors to create a high side NFET gate driver. The system is operated so that when there is a high input the NFET will turn off and when there is a low input the NFET will turn on.

Abstract: A tilt sensor and a method for the use of the tilt sensor to calculate the degree of tilt, whereby the tilt sensor has at least three accelerometers mounted to a base, the accelerometers are positioned in a common plane, and wherein each is preferably at an equally spaced angle from one another.

Abstract: The invention concerns a valve arrangement (1) with at least two valve modules (2, 4, 5), each having a valve element, whose position can be changed by means of an actuator (13, 13a, 13b), and to which a position sensor (19, 19a, 19b) is allocated, a line arrangement (24) being connected with the valve modules (2, 4, 5), through which control signals can be transmitted to the valve modules (2, 4, 5). It is endeavoured to increase the safety of such valve modules. For this purpose, at each valve module (2 to 5) the actuator (13) is provided with a control device (22, 22a, 22b), which is connected with the position sensor (19, 19a, 19b) and evaluates control signals for the valve module (2 to 5) concerned, that at least the control device (22b) of a first valve module (5) additionally evaluates the control signals for another, second valve module (4), and that this control device (22b) receives signals from the position sensor (19a) of the second valve module (4).

Abstract: An electrical conductor is provided for a fluid filled motor having a housing. The electrical conductor comprises insulating elements received by a passage extending through the housing, and a terminal bolt passing through the insulating elements. The electrical conductor further comprises sealing means between the terminal bolt, insulating elements, and the housing, and a fastening nut secured to the terminal bolt compressing the sealing means to seal against fluid flow through the passage. A method of sealing said electrical conductor through the housing of a fluid filled motor also is provided.

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: The invention concerns a driving device, particularly a lifting device for a working vehicle, with a drive in the form of a hydraulic motor, the drive having a first connection and a second connection, a pump and a control valve arrangement between the drive and the pump. It is endeavoured to provide a simple way of extending the functionality of such lifting devices. For this purpose, the control valve arrangement can be switched from a first operating state, in which the motor is driven in a single-acting manner, to a second operating state, in which the motor is driven in a double-acting manner.

Abstract: The invention concerns a hydraulic valve arrangement (1) with a working connection arrangement having a first working connection (A) and a second working connection (B), both working connections (A, B) being connectable with a hydraulic consumer (2), a supply connection arrangement having a pressure connection (P) and a tank connection (T), a first valve arrangement with a first valve (12), closing the pressure connection (P) or connecting it in a controlled manner with the first working connection (A) or the second working connection (B), a second valve arrangement with a second valve (16), closing the tank connection (T) or connecting it in a controlled manner with the first working connection (A) or the second working connection (B), and a control arrangement controlling the first valve arrangement and the second valve arrangement. In such a valve arrangement, it is endeavoured to achieve improved operation behaviour.

Abstract: A hydraulic valve system (1) has a supply connection arrangement, having a high-pressure connection (P) and a low-pressure connection, with a working connection arrangement, having two working connections (A, B), with a control valve (3), which is arranged between the supply connection arrangement and the working connection arrangement, and with a non-return valve (24, 28) for each working connection (A, B). The valve being arranged between the control valve (3) and the working connection arrangement. A tappet (36) mechanically opening the valve element (25, 29) of said non-return valve.

Abstract: A leakage compensation system in a control device (S) has a fully hydraulic steering system (1) with a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T). A working connection arrangement has two working connections (CL, CR), a control section between the supply connection arrangement (P, T) and the working connection arrangement (CL, CR). A control element (2) for activating the control section, a steering member (3) and an auxiliary fluid path (12) has a valve arrangement (A6, A7), through which hydraulic fluid can be supplied or drained off.

Abstract: The invention concerns a vehicle with an attachment, which has a lifting drive with at least one hydraulic cylinder and a control device, the control device having a position sensor and a position generator. It is endeavored to improve the position control of the attachment. For this purpose, the control device has a trajectory generator, which generates a trajectory in dependence of a desired position value and an acceleration limit, said trajectory being optimized with regard to a time specification, and a follower, which controls the lift drive in dependence of the trajectory.