Sauer-danfoss Inc.

Danfoss Power Solutions Gmbh & Co Ohg

Bernd Hames

Reinhardt Thoms

Carsten Fiebing

Markus Reimer

Martin Wüstefeld

Momme Boldt

Howe Gripp

Suenje Marsch

Arne Streblau

J&uuml;rgen Ploog

Michael Hein

Martin W&uuml;stefeld

Bernd H&auml;nisch

The invention relates to a hydraulic machine, in particular to a hydraulic motor with two working lines, from one of which a high pressure line and from the other one a low pressure line is branched off. An electronic control unit and a servo displacement unit are provided to control the displacement of the displacement volume of a drive mechanism of the hydraulic machine, wherein the displacement volume can be determinated by the displacement of a servo piston within the servo displacement unit. For this, the servo piston can be loaded at least on one side via a servo pressure line with hydraulic fluid under servo pressure, wherein the servo pressure level can be adjusted by a control spool arranged moveable within a control valve. For this, hydraulic fluid from the low pressure line or, perhaps, from the high pressure line is guidable via the control valve to the servo pressure line if a suitable control signal is available at a switching valve.

Device and method for controlling a hydraulic machine

The invention relates to a signal inducing device (), comprising a first material () and a second material (). The first material () and the second material () show a different magnetic behaviour. The first material () and the second material () are arranged in a way that the resulting magnetic behaviour of the signal inducing device () varies over a magnetic interaction surface () of the signal inducing device (). The signal inducing device () is designed in a way that the magnetic interaction surface () shows an essentially smooth surface, in particular with respect to the standard moving direction of the magnetic interaction surface ().

Speed sensor ring

The invention relates to a signal inducing device (), comprising a first material () and a second material (). The first material () and the second material () show a different magnetic behavior. The first material () and the second material () are arranged in a way that the resulting magnetic behavior of the signal inducing device () varies over a magnetic interaction surface () of the signal inducing device (). The signal inducing device () is designed in a way that the magnetic interaction surface () shows an essentially smooth surface, in particular with respect to the standard moving direction of the magnetic interaction surface ().

A hydrostatic adjustment unit with a swash plate for adjusting the stroke of displacer pistons which are arranged in a rotating cylinder block is described. The displacer pistons each have a slider block which bears against a support face of the swash plate and is held in abutment by means of a slider block holder. The slider block-holder has a number of bores for receiving the slider blocks corresponding to the number of displacers. The slider block holder at the same time forms the rotor of a rotational speed signal transmitter for determining the rotational speed of the cylinder block.

Hydrostatic adjustment unit with swashplate, rotating cylinder block and a rotational speed signal transmitter

An axial piston machine having a swashplate or an oblique axis which can be adjusted by means of servopistons and has a valve segment and an adjustment unit for the electrically proportional adjustment of the volumetric displacement. The adjustment unit comprises proportional magnets which can be activated electrically, and a control piston for controlling the oil pressure which moves the servopistons. The proportional magnets act on the control piston along a common tappet axis, a feedback device for feeding back the current swashplate or oblique-axis valve-segment position to the control piston being provided. The feedback device comprises spring levers' which can pivot about an axis, the spring levers&#x2032; each being mounted on the pivot axiswith a bearing shell, which are each composed of two component shells which support the spring lever&#x2032; at separate locations on the pivot axis, and which each essentially enclose a half-space about the pivot axis

Axial piston machine having a device for the electrically proportional adjustment of the volumetric displacement

In the housingof a hydraulic machine, the pressure Pi acts in the chamber. For this purpose, a passage openingis provided, which is formed as a valve seat. A valve bodycan be displaced longitudinally in the housingand forms a pressure-tight spring chamber for an inner valve spring. The spring chamber is connected to the chambervia a pressure equalizing hole. The prestress of the inner valve springcan be set by means of a setting screw. In addition, there is an outer valve spring. Both the valve springs load the valve bodywith the effect of closing it. The pressure equalizing valve described combines a compact design with an advantageous flow characteristic. When a maximum value of pis reached, the valve bodylifts off the valve seatand hydraulic fluid from the chamberflows away via the valve chamber

Pressure limiting valve in a hydraulic machine having a pressure limiting valve

An axial piston machine having a swash plate or oblique axis which can be adjusted by means of servopistons and has a valve segment and an adjustment unit for the electrically proportional adjustment of the volumetric displacement, the adjustment unit comprising proportional magnets which can be activated electrically, and a control piston for controlling the oil pressure which moves the servopistons, the proportional magnets acting on this control piston along a common tappet axis. A feedback device for feeding back the current swash plate or oblique axis valve segment position is provided. The feedback device comprises spring levers and a pointer which can be pivoted about an axis, the pointer which is embodied as a two-armed lever engaging in the control piston on one side of the pivot axis, and between the spring levers on the other side.

Axial piston machine having a device for the electrically proportional adjustment of its volumetric displacement

A hydrostatic vehicle drive has a control ( ) for controlling an output torque of the drive and another control device ( ) for controlling the output torque of a hydrostatic drive, the control device ( ) having a controllable pressure-limiting valve ( ) by means of which the working pressure can be adjusted and which is used for sensitive control of the output torque of a hydraulic motor ( ). The pressure-limiting valve ( ) can be controlled by a proportionally adjustable pressure-reducing valve ( ).

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Henstedt-Ulzburg, Germany

Bernd Hames