Brueninghaus Hydromatik Gmbh

Hydromatik Gmbh

Bosch Rexroth Ag

Reinhold Schniederjan

Karl-Heinz Vogl

Markus Gepraegs

Bernhard Adler

Ludwig Wagenseil

Guenter Wanschura

Grit Geissler

Jerzy Kreja

Hermann Hoffmeister

Herbert Kurz

Guenther Wanschura

Jürgen Gintner

Bernhard Wibberg

Klaus Puvogel

Wolfram Kudermann

Markus Geprägs

Werner Hörmann

A pressure limiting valve comprises a valve closing body () which comprises a valve closing surface () which together with a first valve seat () opposing the valve closing surface () forms a first seal seat and a valve closing body orifice (), which is surrounded by a second valve seat () which together with a closing head () configured on an axially displaceable valve bolt () forms a second seal seat and with a spring plate () which is connected to the valve bolt () and axially displaceable therewith, and a first return spring () clamped between the spring plate () and the valve closing body (), which pretensions the valve bolt () against the second valve seat () configured on the valve closing body () and a second return spring () which pretensions a valve unit () against the first valve seat (). In the valve bolt () a longitudinal bore () is provided extending over the entire axial length of the valve bolt ().

Pressure limiting valve with reduced differential area

An axial piston machine of swashplate construction is provided. The axial piston machine has two pivot bearing parts. In order to improve the guiding of a cage segment mounted within a gap between the two pivot bearing parts, a guide element, in the region of its rotary bearing connected to the cage segment is displaceably connected to the cage segment by an elongated guide in a longitudinal direction. The guide member, in the region of its end region connected to the other pivot bearing part, is rotatable by an associated rotary bearing and rigidly connected in the longitudinal direction to one of the two pivot bearing parts.

Axial piston machine with an elongated guide element for a cage segment

The invention related to a hydrostatic drive comprising a hydraulic pump () which is driven by a drive machine () and pumps into at least one first working line (), and a pressure line () in which a feed quantity dependent on the speed of the drive machine () flows. When a differential pressure value in the pressure line () is exceeded, the pressure means can be extracted from the first working line ().

Hydrostatic drive with rotational speed limitation

The invention relates to a hydrostatic drive comprising a hydraulic pump () and at least one hydraulic engine (). Said hydraulic engine () is contacted to a closed circuit via a first working line () and a second working line (). In order to limit the swept volume flowing in one of the two working lines () towards the hydraulic pump (), a volume flow divider () is provided in the working line () and allows to remove a partial volume flow from the working line ().

Hydrostatic drive

The gear pump unit () comprises a pump cover (), an internal rotor () mounted rotatably in a recess () of the pump cover () and formed in a rotationally fixed manner on a driven plug-in shaft (), and an external rotor (), which is rotatably mounted in the recess () of the pump cover () eccentrically relative to the axis of rotation (A) of the internal rotor (). The external rotor () is in mesh with the internal rotor () only in a first angle-of-rotation range (&#x3b1;). In a second angle-of-rotation range (&#x3b2;) lying opposite the first angle-of-rotation range (&#x3b1;), the internal rotor () is in contact with an inner surface () of a web (), which is disposed in the recess (). The outer surface () is in contact with the external rotor (). After closing of the recess () by a cover plate () fastened to the pump cover (), an admission pressure chamber () and a low-pressure chamber () are therefore formed in the recess (). A holding element (), which is held in the pump cover (), in the initial assembled state of the gear pump unit () holds the cover plate () at a fixed angle of rotation on the pump cover ().

Gear pump and holding element therefor

The invention relates to a hydrostatic machine () comprising at least one first hydrostatic unit (E) and one second hydrostatic unit (E), each hydrostatic unit (E, E) comprising respective pistons () guided in respective cylinder drums () and supported by respective swiveling bodies () that can be adjusted by respective adjustment devices (), and further comprising respective control bodies (). A one-piece main housing body () radially surrounds the cylinder drums (), the control bodies (), and the adjustment devices () of both hydrostatic units (E, E), and assigns pressure channels for supplying a pressure medium to and discharging it from the control bodies () of both hydrostatic units (E, E). A first add-on housing body () is disposed on a first side of the main housing body (), and bears a swiveling body () of the first hydrostatic unit (E). On a second side of the main housing body () a second add-on housing body () is provided which bears the swiveling body () of the second hydrostatic unit (E).

Hydrostatic machine

A control circuit, in particular for a slewing gear of a digger, has a hydraulic fluid tank ( ), connected to two adjusting pressure chambers ( ). Each of the connections contains a separate brake valve ( ). The first of the valves ( ) is operated by the differential between the working pressure in the first working conduit ( ), and the control pressure in the control conduit ( ) charged with the higher pressure. The second valve ( ) is operated by the differential between the working pressure in the second working circuit ( ) and the control pressure in the control circuit charged with the higher pressure. Slow braking by the brake valves is interrupted when the slewing gear swings out against a resistance such as a heap of debris.

Slewing gear control system with braking and control valves

The invention relates to a hydraulic controller, in particular for the control of the rotating mechanism of an excavator. In a hydraulic drive circuit a drive hydraulic pump (,) and a drive hydraulic motor are provided, which are connected via working lines (,). The hydraulic controller includes an adjustment arrangement (,) for adjusting a setting piston (,) arranged between two setting pressure chambers (,) and acting upon the displacement volume of the drive hydraulic pump (,). Further, a pre-control arrangement (,) is provided which acts upon one of the setting pressure chambers (,) with a setting pressure, in dependence upon the pressure difference between two control lines (,). In accordance with the development according to the invention, the precontrol arrangement (,) is connected with a feed line (,) via a pressure regulation valve (,), whereby the precontrol arrangement (,), in a control position (,), connects one of the two setting pressure chambers (,) with the feed line (,) via the pressure regulation valve (,) and connects the respective other setting pressure chamber (,) with a pressure fluid tank (,). In a neutral position (,), both setting pressure chambers (,) are connected with the feed line (,) via the pressure regulation valve (,).

Rotary mechanism control with power supply

Rotary mechanism control system with bilateral braking

Hydrostatic transmission with brake valve

The invention relates to a control and regulating device for a hydrostatic transmission which comprises a reversible hydraulic pump that can be driven by a driving motor, at least one hydraulic motor that is connected via two working lines to the hydraulic pump, and an adjusting device that can be acted on by an adjusting pressure for adjusting the volume and direction of displacement of the hydraulic pump, together with a displacement-direction control valve for controlling and regulating the action of the adjusting pressure on the adjusting device, can be actuated as desired both by a control signal that is proportional to the speed of rotation of the driving motor and predetermines the direction of displacement of the hydraulic pump and by a working pressure signal that is proportional to the working pressure in the working line then carrying the high pressure. To enable a load that has been decelerated to a standstill both to be maintained at a standstill and also to be shunted without mechanical braking, even when actuation of the displacement-direction control valve by the control signal is interrupted, the invention provides for switching over the working pressure signal applied to the displacement-direction control valve in the absence of the control signal.

Control and regulating device for a hydrostatic transmission

A swashplate type hydraulic axial piston machine whose swashplate is arranged on a rocker mounted to pivot in a segmental rolling contact bearing has a tracking device for the cage of the pivot bearing which comprises a rod-like guide element which is connected to said rocker in a first bearing in the rocker so that it can pivot parallel to the pivot plane (SE), is connected to said cage in a second bearing so that it can pivot parallel to the pivot plane (SE) and so that it can be displaced longitudinally, and is mounted to pivot parallel to the pivot plane (SE) in a third bearing. To make tracking by the cage possible without mounting the guide element on the housing, a rocker adjustment member is provided mounted so that it can be displaced transverse to the middle axis of the axial piston machine, and the third bearing is arranged on a guide member movably connected to the adjustment member and the rocker.

Swashplate type hydraulic axial piston machine having a tracking device

In a summation power output regulating system for first and second hydrostatic machines (3, 4), having a common drive and comprising at least two hydrostatic transmissions (1, 2), each of the machines (3, 4) having a hydraulic control device (7, 8), wherein the second machine (4) is provided with a hydraulic power output regulator (24) which regulates the pressure acting on the control device (8) in dependence on the power output of the second machine at that time and a control pressure, dependant on the working pressure of the first machine, is transmitted by means of a hydraulic actuator to the power output regulator (24), substantially 100% utilization of the power available is attained with a simple construction and function by providing the first machine (3) with a power output measuring valve (34; 63, 64) which determines the power output at the time and regulates the control pressure (P.sub.3) in dependence on the power output of the first machine.

Summation power output regulating system for at least two hydrostatic

A control apparatus for several drive assemblies, which consist of hydrostatic drive units, is described. The hydraulic pumps of the hydrostatic drives are driven by means of a common prime mover and are controlled in terms of output. The output control device consists of an adjusting piston, which is connected with the control element of the hydraulic pumps and upon both sides of which pressure acts, and of a spool valve which controls the pressure action on both pressure chambers at the front surfaces of the adjusting piston and upon which, on one side, the working pressure of the pumps acts and upon which, on the other side, an adjustable spring acts. In order to give priority to one of the hydraulic pumps or one of the drive assemblies and to allow sufficient output to come from the driving engine in each operating condition, there is provided a measuring piston upon which the working pressure of the priority hydraulic pump acts and which presses on a first lever which counteracts the force of the adjustable spring acting upon the spool valve of the output control apparatus.

Control apparatus for several drive assemblies consisting of hydrostatic

A power regulation device for a hydraulic pump includes a slidable piston having a first end face with a first diameter and a second, opposite end face with a smaller diameter, the second end face being biased by operating fluid pressure from the hydraulic pump and the first end face being biased by an adjustable fluid pressure for controlling the operation of the hydraulic pump; a compression spring which biases the piston in a direction against that of the adjustable fluid pressure; a measuring spring, one end of which biases the piston in the same direction as the compression spring; a power valve having a control slider member which is biased in one direction by the other end of the measuring spring and by the operating fluid pressure from the pump and in the opposite direction by a compression spring, the control slider member including a transverse channel for supplying the adjustable fluid pressure to the first end face of the piston during idling and normal operations and for connecting the adjustable fluid pressure at the first end face to a pressureless drain when the operating fluid pressure of the pump exceeds a first predetermined level; and a pilot valve including a control slider member biased in one direction by a spring and in the opposite direction by a fluid pressure, the control slider member of the pilot valve including a transverse channel for connecting the adjustable fluid pressure at the first end face of the piston to a pressureless drain during no-load and idling states of the hydraulic pump.

Growing community of inventors

Neu-Ulm, Germany

Reinhold Schniederjan