Bosch Rexroth Ag

Robert Boschgmbh

Jörg Dantlgraber

Rudolf Scheidl

Bernd Schnurr

Helmut Behl

Bernd Winkler

Richard Bauer

Steffen Kunkel

Karl-Günter Herrmann

Michael Hörning

Berno Kobelbauer

Stephan Becker

Gunther Neidlein

Heino Försterling

Marek Chmiel

Holger Englert

Alexander Mark

There is disclosed a radial piston machine comprising a cylinder block having at least one bore in which a piston supported on an eccentric disk is movably guided via roll bodies, wherein at least one hydrostatic relieving field is provided between the piston and the roll body. According to the invention, the active surface Aof the relieving field is equal to or larger than the active piston area Aof the piston restricting a cylinder chamber and the relieving field is in fluid communication with the cylinder chamber via a hydraulic resistance.

Radial piston machine

An actuating drive for a rotor blade in a wind power installation is provided with an electric motor and a frequency converter which has a rectifier that is to be fed from a power supply system, a link connected to the rectifier, and a d.c.-to-a.c. inverter for feeding the motor, the link carrying a specified nominal operating voltage in a network-fed normal operation of the frequency converter. Furthermore, an auxiliary energy supply device is provided that is connected to the link. The auxiliary energy supply device includes and energy store which makes available a support voltage that amounts to less than 80% of the nominal operating voltage of the link. A diode is connected between the energy store and the link, and is arranged, with regard to its forward direction, in such a way that it feeds a support voltage from the energy store into the link if the link voltage falls below the support voltage. The diode prevents a current flow between the energy store and the link if the link voltage is greater than the support voltage. A charging device for the energy store has a lower charging voltage than the nominal operating voltage of the link.

Actuating drive and emergency energy supply device

An on-off valve is disclosed, especially a fast-acting on-off valve, wherein a plunger is pretensioned in a base position. The plunger has a plurality of parallel control edges via which a plurality of sectional opening cross-sections, arranged in parallel in a hydraulic manner, can be jointly actuated to open or close when the valve is switched.

On-off valve

A drive mechanism for an injection molding machine has an output element that is moveable in a straight line and an electric motor drive unit having an electric motor and a piston-cylinder unit which has a first piston-cylinder unit in the force chain between the output element of the electric-motor drive unit and the movable component. A rapid actuating movement is possible and, the action of a high force is also achievable wherein a second piston-cylinder unit and a third piston-cylinder unit. A fluidic connection between the first cylinder chamber and the second cylinder chamber is controllable via a valve. When the valve is open, the second hydraulic piston displaces pressurized liquid from the second cylinder chamber into the first cylinder chamber, to actuate the movable component and, when the valve is closed, the third hydraulic piston displaces pressurized liquid from the third cylinder chamber into the first cylinder chamber to exert a high force on the movable component.

Drive mechanism, particularly for a closing unit, an injection unit or an ejector of a plastic injection moulding machine

An injection unit for a plastic injection molding machine having a screw, having a motion spindle as first drive element, via which the screw can be rotationally driven for the plasticization and is movable in the axial direction for the injection, having a spindle nut as second drive element, which is coupled to the motion spindle via a motion screw thread, having a large electric motor which is arranged so as to be fixed to the frame and by which, while one drive element is held against rotation, the other drive element can be rotationally driven for moving the screw during the injection, and having a device which is arranged so as to be fixed to the frame and by which a rotational speed of the one drive element can be preset during the plasticization, this rotational speed being different from the rotational speed at which the large electric motor simultaneously drives the other drive element. In a known injection unit of this type, two equally large electric motors, which can both apply a large torque, are used, by which such a counter-torque is exerted on the motion spindle during the injection operation that the motion spindle does not rotate. On the whole, the known injection unit is quite expensive on account of the two electric motors designed for a high torque. In order to provide a more cost-effective injection unit, the drive element held against rotation during the moving of the screw for the injection can be locked by a releasable mechanical brake.

Injection unit for a plastic injection moulding machine

A drive device has a drive element movable axially by means of an electric motor and a hydraulic unit. In the drive device it is important to execute a rapid adjusting movement and then to exert high forces. This causes high reaction forces on the lifting spindle. High reaction forces are avoided if a force intensifier with two pistons movable in relation to one another and differing from one another in the size of their active surfaces along with an intermediate part which, together with the pistons, encloses a pressure space filled with a pressure fluid is used, if the smaller active surface is connected mechanically to the drive element, for the adjusting movement, the hydraulic unit can be moved as a whole, and if, for exerting a high force by means of the larger active surface, the intermediate part can be blocked against displacement in relation to a fixed stand.

Drive mechanism, particularly for a moveable part of a closing unit or the injection unit of a plastic injection moulding machine

A drive device for closing unit, injection unit or ejectors of a plastics injection molding machine, has a drive element which is axially moveable, and a hydraulic unit which is moveable by the drive element in the same direction as the drive element. The hydraulic unit is a force multiplier with a large piston and a first small piston, which are moveable in relation to one another and differ in size of their effective surface areas. An intermediate part together with the pistons encloses a pressure chamber filled with a pressure fluid. The first small piston is mechanically connected to the drive element. A second small piston with the intermediate part define a fluid chamber connected by a valve, in one embodiment, to the pressure chamber. The hydraulic unit as a whole is moveable for the positioning movement and the intermediate part is blockable against displacement in relation to a fixed frame.

Drive device, particularly for the closing unit, the injection unit or the ejectors of a plastic injection molding machine

A drive device which is used in particular for the closing unit, the injection unit or the ejectors of an injection molding machine for plastics and which has a drive element which can be moved axially by an electric motor, and a hydraulic unit which can be moved in the same direction as the drive element by moving the latter. In drive devices for the applications, it is important to first of all perform a rapid regulating movement and then exert high forces. In a known drive device having these features, the hydraulic unit is a hydraulic cylinder which is adjusted by the electric motor via a stroke spindle during the regulating movement and to which pressure medium is fed via a valve for exerting a high force. In this known drive device, in addition to the electrical installation, a complete hydraulic system is also necessary. In addition, high reaction forces act on the stroke spindle. This is avoided wherein the hydraulic unit is a power transmission means having two pistons, which are movable relative to one another and differ from one another in the size of their effective areas, and having an intermediate part which together with the pistons encloses a pressure space filled with a pressure fluid, if the small piston having the smaller effective area is mechanically connected to the drive element, if the hydraulic unit can be moved as an entity for the regulating movement, and if, for exerting a high force by the large piston having the larger effective area, the intermediate part can be locked against displacement relative to a fixed frame.

Drive device, in particular for the locking unit, the injection unit or the ejector of an injection-moulding machine for plastics

A drive device which is intended for displacing two linearly movable components of a plastics injection-molding machine at least partly at successive times, in particular for displacing the injection unit for bringing the injection nozzle into contact with a mold and for displacing the injection mechanism for injecting polymer into the mold. With a known drive device, arranged downstream of an electric rotating motor are two clutches, by which rotational movements are transmitted on the basis of frictional engagement, and with which wear accordingly occurs. Each clutch is followed by a threaded drive, by which the rotational movement of the output element of a clutch is transformed into the linear movement of the machine component to be displaced. To make the known drive device for a plastics injection-molding machine less susceptible to wear and less costly in a first way the threaded drive is arranged between the electric motor and the two clutches and, for displacing the one movable component, the linearly movable drive output element of the threaded drive is able to be moved beyond the displacement distance necessary for displacing the other movable component. In a second way the electric motor is an electric linear motor with a linearly movable drive output element, arranged downstream of which in the force chains are the two clutches, and for displacing the one movable component, the drive output element is movable beyond the displacement distance necessary for displacing the other movable component.

Drive device for displacing two linearly moveable components pertaining to a plastic injection moulding machine

An electromechanical clamping device with hydraulic assistance. A thrust mechanism driven by an electric motor displaces two clamping jaws with respect to each other along a guide device. One clamping jaw is divided into two mutually displaceable part java. A chamber to hold pressure medium is formed between the part jaws. The first part jaw can be displaced along the guide device and locked with respect to the latter. One part jaw is provided with a first cylinder coupled to the output of the thrust mechanism. In order to close the clamping device, in a first step the thrust mechanism pulls the part jaws against the other clamping jaw, and in a second step the thrust mechanism delivers pressure medium from the first cylinder into the chamber between the two part jaws, with the first part jaw locked with respect to the guide device. To open the clamping device, in a first step a second cylinder arranged between the two part jaws pulls the part jaws against each other, with the first part jaw locked with respect to the guide device, and then in a second step the thrust mechanism forces the part jaw coupled to it in the opening direction, forcing the other part jaw with it, with the first part jaw unlocked from the guide device. The clamping device is provided for production machines, in particular for injection molding machines.

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Lohr am Main, Germany

Jörg Dantlgraber