Danfoss A/s

Erik Kyster

Svend Erik Thomsen

Hans Christian Petersen

Soren N Sorensen

Kurt Harck

Holger Nicolaisen

John Guttorm Abrahamsen

Jens J Molbaek

Bjarne Straede

Michael Boisen

Carl O Flagstad

Niels-Henrik G Jakobsen

Ole Stenderup

An electromagnetic valve assembly having upper and lower modules. A standardized lower module can be joined with one of several upper modules having a different axial length for varying the magnetic field strength of a coil arrangement in the upper module without changing the length or position of an armature tube in the lower module.

Electromagnetic valve top part

An inlet nipple and a housing having a water passage extending therethrough that have first, second and third water bore portions of progressively larger diameters in a downstream direction. A variable throttle point is formed by a fixed member and a movable member acting in conjunction with the bore portions that produce a turbulent flow causing cavitation downstream of the throttle point independently of the quantity of flow. In one embodiment the movable member includes a closure portion seatable against a seat formed at the intersection of the bore portion and an annular portion that in conjunction with a bore portion forms an annular water flow space downstream of the closure portion. In the second embodiment the fixed member has a closure portion converging toward an aperture in the movable member which is in the shape of a cup. A filter insert is secured to the housing to collect precipitated material while a layer of galvanically soluble metal is provided on the movable member to have water flow thereover.

Apparatus for decalcifing water by producing turbulence

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.

Hydrostatic control device, particulary steering device

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.

Hydrostatic control device, particularly steering device

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.

Hydraulic control apparatus for a servo-motor, particularly for vehicle

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.

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.

The invention relates to a steering assembly having a bidirectional servomotor of the differential piston type which is connectable to steerable wheels. A directional control valve unit has a spool valve with two collars which cooperates with the housing to form first and second end control chambers and a middle chamber. A power circuit supplies pressurized fluid equally to the end control chambers and a manually operable control pump is operable to selectively and incrementally increase and decrease the pressures in the end chambers in a push-pull mode to effect movement of the servomotor piston in either direction. The control valve has two ports connected to opposite ends of the servomotor with one port providing fixed and constant fluid communication between the first valve chamber and one side of the servomotor. The other valve unit port is cooperable with one of the collars of the spool valve to provide a dual throttling action wherein oppositely acting throttling occurs between the port and the middle and second valve chambers depending on the axial position of the spool valve. Control pressure from the manually operated pump which moves the spool valve incrementally one way or the other causes the throttling collar to either admit additional pressurized fluid to the associated end of the servomotor or release pressurized fluid therefrom to the middle chamber.

Hydraulic control apparatus particularly steering apparatus

The invention relates to a hydrostatic steering control unit of the type having valving for an open center neutral position which bypasses pressurized fluid from the pump to the tank when in neutral. During a turning operation with a steering wheel the open center valving is caused to close and the pressurized fluid is directed to one side or the other of a servomotor which is connected to wheels to be steered. The open center valving includes orifices in relatively rotatable elements which are aligned in the neutral position and closed to effect the turning operation. Open center valving can be the cause of noise and cavitation and such valving herein is provided with slot shaped orifices and flat generally wedge shaped throttle passages to minimize the noise and cavitation problems. The throttle passages are defined by curved bounding surfaces having rectangularly shaped outlines.

Hydraulic control apparatus

The invention relates to a hydrostatic steering control unit of the type having valving for an open center neutral position which bypasses pressurized fluid from the pump to the tank when in neutral. During a turning operation with a steering wheel the open center valving is caused to close and the pressurized fluid is directed to one side or the other of a servomotor which is connected to wheels to be steered. The open center valving includes orifices in relatively rotatable elements which are aligned in the neutral position and closed to effect the turning operation. Open center valving can be the cause of noise and cavitation and such valving herein is provided with slot shaped orifices and flat generally wedge shaped throttle passages to minimize the noise and cavitation problems. The throttle passages are defined by curved bounding surfaces having rectangularly shaped outlines. A characteristic of the curved surfaces is that they are formed with exponentially shaped sections.

Hydraulic control apparatus with an adjustable throttle

The invention relates to hydraulic control unit for a power steering assembly. The unit is of the type having a metering motor and steering wheel actuated valves for directing metered, pressurized fluid to one selected port of a steering servo-motor and drawing fluid from the other port of the servo-motor to a tank. The invention involves a particular regulating valve for directing pressurized fluid to consumer units when the steering control is in neutral.

Hydraulic control means, particularly steering means

The invention relates to a steering control system for a bidirectional servomotor connectable to steerable wheels. The servomotor may be of the differential type in which a rod extending from one side of the piston thereof causes the effective areas on opposite sides of the piston to be unequal. A steering control unit controlled by a steering wheel has two motor ports connected to opposite sides of the servomotor and pump and tank ports connected to pump and tank units. The steering control unit has a metering motor controlled by the steering wheel which meters fluid to and away from only one side of the servomotor. The steering control unit has oppositely acting valves which may be throttle valves for establishing flow paths for opposite steering directions and the neutral condition.

Hydrostatic control device particularly a steering device

The invention relates to a hydraulic steering system of the type having a servomotor controlled by a steerable valve assembly which directs metered quantities of pressurized fluid to the servomotor and has a feedback arrangement for stopping the flow of fluid when the steering motion is stopped. The system involves an arrangement wherein the metering unit is arranged downstream from the servomotor and an auxiliary valve is provided for automatically accommodating normal conditions as well as emergency pump failure conditions and overpressure conditions caused by the servomotor reaching an extreme end position in the operation thereof.

Hydrostatic steering gear

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.

Hydrostatic steering device

The invention relates to a hydrostatic control unit of the metering type utilized for some automotive type power steering systems. The control unit has a valving section with inlet and outlet ports connectable to a pump and a tank and two working ports connectable to opposite sides of a bidirectional servomotor which is connectable to wheel steering linkage. A metering motor controlled by the valving section supplies and exhausts metered fluid to and from the servomotor through the two working ports of the valving section. The valving section has a single movable slide element cooperable with a stationary housing member. A gearing unit which may be of the planetary type is provided having two inputs and one output with the two inputs being connectable to the vehicle steering wheel and the metering motor input shaft and the output being connectable to the slide valve element. The steering wheel and metering motor inputs always act in opposite directions on the valve element such that a movement of the valve element away from a neutral position by the steering wheel is always followed by movement of the valve element back towards the neutral position by the shaft of the metering motor.

Growing community of inventors

Augustenborg, Denmark

Erik Kyster