Brueninghaus Hydromatik Gmbh

Hydromatik Gmbh

Werner Hormann

Jochen Beck

Manfred Blum

Norbert Ruckgauer

Reduction and control valve

The invention relates to a hydrostatic machine, in particular axial piston machine, having a machine housing the internal housing chamber of which accommodates a drive mechanism rotatably mounted by means of at least one bearing and has a leakage oil chamber opening to the outside via at least one leakage oil connection. To avoid splash losses of the hydrostatic machine, in accordance with the invention a pump device (29; 50; 60; 70) is arranged in the internal housing chamber in driving connection with the drive mechanism (3, 4, 7), which device is provided to pump leakage oil out of the leakage oil chamber (28) through the leakage oil connection (8, 37; 72) to the outside.

Hydrostatic machine with leakage oil discharge

A hydrostatic machine which includes a housing having an internal space accommodating a rotatably journaled driving mechanism, and wherein the portion of the internal space which is not occupied by the driving mechanism encompasses a drain oil chamber which receives the drain oil inclusive of lubricating oil which is discharged from bearing locations of the hydrostatic machine, and which is connected or port to a tank through at least one drain oil connection of the housing and through a drain oil line. A pump is arranged in the drain oil line which is in a driving or operative connection with the hydrostatic machine, and which pumps off drain oil from the drain oil chamber during the operation of the hydrostatic machine, and possesses an output delivery correlated in such a manner therewith that the drain oil remaining in the drain oil chamber assumes that particular specified level in the lower region of the drain oil chamber, at which at least no splashing losses are encountered due to the rotation of the driving mechanism in the drain oil which exceed the mechanical losses of the hydrostatic machine.

Hydrostatic machine with drain oil discharge

The invention relates to a power control device for two variable displacement pumps, each with an adjusting device which can be acted upon by adjusting pressure, a power control valve associated therewith, which is acted upon by a first control pressure corresponding with the operating pressure of the variable displacement pump to be adjusted against a pressure difference in the direction of the control position, in which the adjusting pressure loading is controlled in the direction of reduced displacement of the variable displacement pumps along a hyperbolic control curve, whereby the pressure difference results from a spring-arrangement backpressure counteracting the first control pressure and a second control pressure corresponding with the operating pressure of the other variable displacement pump and with increase of the same drops from a maximum value to a minimum value. In order to set the latter value with the device, it is provided in accordance with the invention that the spring arrangement comprises a first and a second pressure spring, the first pressure spring is set to a force corresponding with the minimum value (.DELTA.p.sub.min) and the second pressure spring is set to a force corresponding with the difference (.DELTA.p.sub.max -.DELTA.p.sub.min) between maximum value (.DELTA.p.sub.max) and minimum value (.DELTA.p.sub.min) of the pressure difference, and the first pressure spring with its setting force and the second pressure spring with a force decreasing with increasing second control pressure act upon the power control valve.

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Illertissen, Germany

Werner Hormann