Mannesmann Rexroth Corporation

G. L. Rexroth Gmbh

Siemens Aktiengesellschaft

Die G. L. Rexroth Gmbh

Reiner Bartholomaus

Hans Wolfges

Christoph Gibas

Michael Ulm

Heinz Schulte

Herbert Lembke

Helmut Patze

Michel Rivolier

Gerhard Gerl

Karlheinz Widmann

Karl Schiene

Franz X Lacher

Rolf Neuhaus

Liebhart Zaiser

Hans-Dieter Kokus

Wolfgang Eberhard

Karl-Heinz Bernhardt

Ferdinand Hess

An actuating system is provided that includes a differential hydraulic cylinder containing a piston and a piston rod connected to one side of the piston. A first or head chamber (53) is defined in the cylinder and is bounded by the one side of the piston, to which the piston rod is not connected. A second or rod chamber (54) is also defined in the cylinder and is bounded by the other side of the piston, to which the piston rod is connected. An actuatable assembly is provided that is adapted to be connected to either the hydraulic cylinder or the piston rod. Finally, a proportional control valve is provided which is adapted to actuate the hydraulic cylinder by controlling the amount of fluid supply to the first chamber, wherein the supply pressure is connected to the second chamber.

Rear wheel steering system

Proportional magnet having a housing in which an armature bar is mounted which is movable under the influence of an armature winding arranged in the housing, wherein a hydraulic unit serving to operate the armature bar is additionally provided.

Proportional magnet

In the pressure regulation of a variable displacement pump very high pressures can build up in the pump delivery line if at the consumer no discharge of the fluid takes place, for example the piston of a servo motor moves against a stop. A pressure regulation of the pump is then only possible via the inner losses of the pump. Consequently, although the pressure can be built up rapidly it can only be reduced very slowly. According to the invention the pressure reduction is via a bypass which is controlled by the control valve of the variable displacement pump and which connects the pressure side of the pump to a tank discharge when the control valve is driven in the sense of a reduction of the pump pressure. According to the invention a very rapid pressure reduction is obtained so that the variable displacement pump can again be pressure controlled.

Control valve for a variable displacement pump

A slide valve, in particular the piston of a switching valve, is actuated in both directions of adjustment by a pressure medium which acts on the annular face and/or the circular face of a regulating piston fixed one-sidedly to the slide valve. The equalization of the differing controlling forces, determined by the different sized surfaces of the regulating piston that are subjected to pressure, is achieved by means of a spring or by an hydraulic counterforce.

Device for the actuation of a slide valve

Electromagnet solenoid with a housing in which a winding support supporting the magnet winding is arranged, having an armature which supports at least one stem and is mounted to be capable of moving to and fro within the winding support, and with end pieces terminating the housing. For guiding the armature a sleeve made of magnetic material is provided within the winding support, and said sleeve has on its surface directed towards the armature a sliding coating defining an air gap (i.e. a space free of magnetic material,) and in addition to serving for guiding the armature the said sleeve serves for redirecting magnetic flux.

Solenoid having low-friction coating internally of the armature sleeve

A pressure reducing valve comprises a valve housing having an axial bore coupled to a fluid operated load device, and first and second transversely extending control bores coupled to a supply tank and a fluid pressure source, respectively. A control slide is axially shiftable in the axial bore and has first and second pistons controlling fluid flow through the control bores. The fluid pressure supplied to the load device acts on a first end of the control slide. A proportional electromagnet has a plunger which contacts and applies force to the opposite end of the control slide. A first restrictor provides fluid communication between the control slide ends, while a second restrictor provides fluid communication between the control slide opposite end and the supply tank.

Pressure reducing valve

A pressure control valve arrangement includes a control slide valve body which is slidably accommodated in a central bore of a valve housing. The control slide valve body is acted upon at one of its axial sides by the controlled pressure, and at its other axial side by a tappet of a proportional electromagnet. The proportional magnet has a magnet housing which is rigidly connected to the valve housing. To provide a pressure control valve arrangement in which the accuracy of the pressure control is not influenced by disturbing factors, a pressure indicator is accommodated in the magnet housing; at least the pressure-responsive member of the pressure indicator is acted upon by the controlled pressure, which is supplied thereto through a connecting bore in the magnet housing and a part of the central bore of the valve housing in which the controlled pressure prevails. A connecting line of the pressure indicator is lead to the exterior of the magnet and valve housings for derivation of the measured value therefrom. The measured value may then be compared with a reference value, and the result of the comparison may be used for controlling the coil of the proportional magnet, possibly after amplification.

Pressure control valve arrangement

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.

Hydraulic control- and/or measuring device, particularly

A hydraulic control arrangement with a feedback device for positioning an implement comprises a positioner including a fluid operated cylinder and piston unit, the piston of which is connected by a plurality of linkage elements to the implement. A first pump delivers through a pressure line fluid under pressure into the cylinder. A two-port three-position valve is interposed in the pressure line movable from a neutral position in which the fluid fed by the first pump is directed to a reservoir, to two operating positions to opposite sides of the neutral position, and in which one of the operating positions fluid fed by the first pump passes into the cylinder and in the other of the operating positions fluid from the cylinder can flow to the reservoir. A pair of pilot chambers are arranged at opposite ends of the valve for moving the latter from the neutral to either of the working positions. A second pump provides fluid under pressure for operating the valve. A first control line leads from the second pump to one of the pilot chambers and a fixed throttle cooperating with an operator adjustable throttle is located in the first control line. The arrangement includes also a feedback device comprising a second control line leading from the second pump to the other pilot chamber and a second fixed throttle cooperating with a second adjustable throttle is located in the second contial line. The flow-through cross-section of the second adjustable nozzle is adjusted by engagement with one of the linkage elements.

Hydraulic positioner with feedback device

A flow meter comprises a housing defining a fluid inlet passage and a fluid outlet passage; a piston defining a jacket surface and a base surface is arranged in the housing for reciprocating movement between the two passages; a biasing spring urges the piston into a zero flow position in which the piston interrupts the communication between the two passages; the base surface of the piston faces the inlet passage so that the fluid flow displaces the piston into a flow position; flow distributing means in the form of a partition arranged in the outlet passage has a plurality of slots shaped for adjusting the flow rate between the two passages according to the variation of the spring bias of the moving piston; and an electrical position detector coupled to the piston to generate an electrical signal proportional to the displacement of the piston.

Growing community of inventors

Neuendorf, Germany

Reiner Bartholomaus