Mannesmann Rexroth Corporation

Die G. L. Rexroth Gmbh

Hans Wolfges

Reiner Bartholomaus

Christoph Gibas

Gotz-Dieter Machat

Karl Schiene

Norbert Gehrig

Wolfgang Volpert

Ferdinand Hess

Eugen Ebert

Pilot-operated proportional pressure limiting valve

A pressure control valve is provided comprising an inlet bore, an annular channel and a control spool. So as to obtain a low control deviation and good stability an annular channel is provided at the outlet side of the valve. The axial extension of said annular channel is smaller than the outlet flow area formed by said bores.

Pressure control valve

A 3/2 proportional control valve is provided with an actuating piston which is subjected to the control pressure set in a pilot valve. The area relationships of the actuating piston are so chosen that at the actuating piston a high pressure gradient obtains and the adjustment dynamics of the regulating piston are increased.

Control valve

A proportional throttle valve which varies the throttle cross-sectional area in dependence upon a control signal and thus governs the flow rate. The invention relates to a throttle valve in which the position of the valve member remains constant independent of pressure fluctuations upstream and downstream of the throttle cross-section. For this purpose the pressure acts on equisized opposing faces of the valve member. An annular face of equal magnitude lying opposite the control face is subjected to the pressure in a line leading from the pressure-limiting valve for setting the control pressure to the tank so that pressure fluctuations in this tank line cause corresponding variations of the control pressure and the position of the valve member remains constant.

Proportional throttle valve

A pilot-controlled proportional throttle valve is provided having pilot oil passage means provided in the spool of said throttle valve.

Hydraulic apparatus, in particular a 2-way proportional throttle valve

The invention refers to a pressure reducing valve including a pilot valve. The main piston of the pressure reducing valve allows to selectively connect a load port to either a port connected to a pressure source or to a port connected to the reservoir. The pilot valve is connected to a control pressure line and to the reservoir. The main piston controlled connection to the reservoir opens within the valve housing into a port connecting the pilot valve to the reservoir. This provides for a substantially simplified construction of the valve since there are only two operating ports and a reservoir port. Furthermore, the main piston is engaged by a spring which is capable of becoming activated such that dynamic stresses resulting from a change from high to low pressure values are avoided which vibrations are detrimental in generating pressure peaks as well as pressure breaks.

Pilot valve operated pressure reducing valve

A device for controlling a consumer, in particular a hydromotor includes a restrictor, preferably an electrohydraulic proportional directional control valve, and a control valve operating on the basis of a releasable non-return valve. The control valve is provided with an actuating cylinder-and-piston unit having control ports and a biasing spring for the piston. The control valve also has a connecting port which is connected with a connecting port of the restrictor. In order to substantially simplify the structural design of the device, a flow regulator is installed between the control port of the control valve and the connecting port of the restrictor which is connected with the consumer. The control sides of the flow regulator and the control valve are connected through a throttle with a supply container. The space of the cylinder-and-piston unit adjoining the control side of the control piston is connected with another connecting port of the control valve and with the restrictor.

Device for controlling a hydromotor

A pressure-reducing valve is secured to a proportional magnet by resiliently connecting the valve sleeve of the valve receiving the piston to the housing of the proportional magnet, thus avoiding possible deformations of the valve sleeve resulting from mounting. Furthermore, the operational safety of the valve is improved by abutments limiting the stroke of the valve piston and by a control edge which is additionally provided at the valve sleeve.

Electrically controlled pressure reducing valve

The invention relates to pressure relief valves which spring bias is controlled by a proportional magnet. The force applied by the proportional magnet is increased by an additional hydraulic pressure force which acts on the spring. There is the advantage of decreasing the size of the proportional magnet and/or increasing the flow capacity of the valve.

Electrically controlled pressure relief valve including a hydraulic bias

An inductive measuring transducer impermeable to pressure media for use with a fluidic adjusting member such as a multiple position valve as a receiving casing of non magnetic working material for receiving a magnetic core, coils surrounding the casing which are, in turn, surrounded by a housing. An operating rod passes into the casing through a connecting member and operates the core. The casing is formed as continuous, hollow cylindrical tube with a closing member or plug inserted in one end and attached in fluid tight relationship. The other end of the receiving casing is tightly connected with the connecting member which is formed as a separate part from the receiving casing.

Inductive measuring transducer for a fluidic adjusting member

The hydraulic control- and/or measuring device has a housing and a socket-shaped control slider movable in a cylindrical bore in the housing between an open position in which it passes a pressure fluid from an inlet opening to an outlet opening; a stationary jet intercepting member projects into the blind bore of the slider and has a deflection disk located outside the range of the inlet opening to intercept fluid energy at the beginning of the opening phase.

Growing community of inventors

Lohr, Germany

Hans Wolfges