Abstract: A hydraulic machine is disclosed, having an annular gear with internal teeth and a gearwheel with external teeth mounted eccentrically therein, the internal teeth comprising one more tooth than the external teeth and the teeth of at least one set of teeth being formed by rotatably mounted rollers. It is desirable in such a machine for the internal seal to be improved and wear to be reduced. To that end, each roller has in its surface at least three axially parallel recesses, in which the teeth of the other set of teeth engage.

Abstract: The control arrangement may be used for vehicles or in other steering systems and includes a steering motor that is adjusted as a function of hand operated steering mechanism, the steering mechanism controlling a directional section and a metering motor section. The directional section is fluidly connected between the steering motor and both of a tank and the metering motor section. A pump is connected between a tank and the metering motor section. The one sides of electromagnetic plus and negative valves are fluidly connected between the fluid connection of the metering motor section and the directional section while the opposite sides are respectively connected to the connection of the pump and the metering motor section and the connection of the directional section to the tank. A processing device for controlling the valves is provided for sensing the steering angle error. The control arrangement provides a simple structural arrangement to compensate for leakage.

Abstract: A gear wheel assembly of the type having an externally toothed gear wheel and an internally toothed ring wheel with the gear wheel having one less tooth than the ring wheel and the wheels having eccentrically spaced axes with said gear wheel being rotatable about the gear wheel axis which in turn is orbitable about the ring wheel axis. Each tooth of the gear wheel has a flank on each side of the tip thereof with each said flank having a shallow recess formed thereon. Each such recess has three successive curved sections with each such recess starting and ending with the same tangent as the respective adjacent part of the associated flank. With this gear construction an automatic braking action is generated in the absence of hydraulic pressure.

Abstract: A stepped piston is axially displaceable in the stepped piston valve chamber and has a front face facing the front face of the valve seat and an axially opposite surface formed at the juncture of its piston head portion to its reduced diameter shaft portion. The piston has an axial through-bore that opens to fluid connecting bore in the valve housing while the housing has a second fluid connecting bore. The piston is displaceable in the chamber between an open position permitting substantial fluid flow between the connecting bores and a closed position having its front face resting against the valve seat face to permit a leakage flow gap between the faces when pressurized fluid acts against the piston surface and block substantial fluid flow between the first bore and the second bore. A spring in the chamber urges the piston toward its closed position.

Abstract: The invention relates to a hydrostatic control device for steering unit device which includes a metering motor and a flat slide directional valve. Slide surfaces of the directional valve are formed by the abutting end faces of an outer housing and a motor housing and between the two slide surfaces there is formed a high pressure zone. Between two end faces of the outer housing and the motor housing opposite thereto is an intermediate pressure zone of larger area which is connected between a first throttle gap associated with the high pressure zone and a second throttle gap leading to the low pressure zone. With the aid of the high pressure zone and the intermediate pressure zone equilibrium can be obtained while incurring only a minimum amount of friction.

Abstract: A ring and star type gear set is disclosed with recessed passages 32 that serve to communicate the fluid chambers about the line of eccentricity.

Abstract: The invention relates to a hydrostatic steering control device of the type having two motor ports connectable to a servomotor and a metering unit for metering the flow of fluid to or from the servomotor in accordance with the rotational movement of a steering wheel for operating the control device. The invention is directed to a way of balancing the distributing valve of the control device by subjecting opposite sides thereof to high and intermediate pressure zones and providing a throttle gap between the high and intermediate pressure zones and a second oppositely acting throttle gap between the intermediate pressure zone and a third zone of lower pressure.

Abstract: The invention relates to a hydrostatic steering control unit of the type having a metering motor for supplying metered pressurized fluid to external servomotor. The unit has a throttled controlled passage which bypasses the metering motor and has a flow therethrough which has a definite relationship to the flow through the metering motor. In this way a comparatively large amount of pressure fluid can be supplied to the servomotor even though the flow capacity of the metering motor is much smaller.

Abstract: The invention relates to a hydrostatic steering control device of the type having two motor ports connectable to a servomotor and a metering unit for metering the flow of fluid to or from the servomotor in accordance with the rotational movement of a steering wheel for operating the control device. The invention is directed to a way of balancing the distributing valve of the control device by subjecting opposite sides thereof to high and intermediate pressure zones and providing a throttle gap between the high and intermediate pressure zones an a second oppositely acting throttle gap between the intermediate pressure zone and a third zone of lower pressure.

Abstract: A geroter hydrostatic steering control is disclosed in which the directional valve is spring biased to a neutral position. The rotor, the commutating valve, the rotor casing and the directional valve are all axially aligned adjacent to each other thus reducing the overall axial length of the device.

Abstract: A gerotor type star and ring gear machine in which control orifices in the star gear alternatively register with ports in the end wall. The star gear is formed from a series of plates and has two sets of control orifices formed therein with one set being diametrically opposed to the second set.

Abstract: The invention relates to a fluid pressure operated motor or pump of the type having a gerotor displacement mechanism which normally includes inner and outer wheel and ring gears which in operation have relative rotational and orbital movement therebetween. Such devices inherently have a form of valving wherein, with a commutating type of action, fluid is directed from the casing inlet to expanding chambers of the gerotor and directed from collapsing gerotor chambers to the casing outlet. Two embodiments are presented in which the first has the casing thereof fixed in space. In both units the commutator valving includes valving patterns in two valve plates attached to opposite sides of the casing and in the wheel gear which has orbital movement relative to the casing.

Abstract: The invention relates to a hydraulic torque amplifier for steering devices or the like. The amplifier has a planetary type piston motor having a rotatable externally toothed inner gear and an orbitable, nonrotatable internally toothed outer gear. The amplifier has input and output shafts rotatably journaled in the amplifier housing in coaxial and axially spaced relation. The valving arrangement includes inner and outer sleeves with the input shaft being fixedly connected to the inner sleeve and the output shaft being fixedly connected to both the inner gear and the outer sleeve.

Abstract: The invention relates to a hydrostatic steering device comprising a servo-motor operable in dependence on direction and a control device having connections for a pump, a tank and the servo-motor as well as a valve arrangement which influences the flow of pressure medium from the pump to the servo-motor and from the latter to the tank and having two valve members which are relatively movable against the force of a neutral position spring depending on the comparison of the adjustment of a steering element and the follow-up motion of a metering motor.

Abstract: The invention relates to an improvement in the spring arrangement of the control valve assembly of a hydrostatic steering unit of the type having a measuring motor and relatively rotatable inner and outer concentric tubular valve members. In this type of unit one of the valve members is connected to the motor and the other valve member is manually rotated for steering purposes. The valve members have axially aligned and diametrically arranged slots for housing the spring arrangement which includes a pair of curved leaf springs and two supporting plates which may also be leaf springs.