Mali Holding Ag

Markus Liebherr

Josef Häglsperger

Peter Dziuba

Josef Bauer

Manfred Kirchhoff

Johann Federholzner

A continuously variable hydrostatic transmission () having torque division for a vehicle comprises a first hydrostatic unit (H) operating as a pump and a second hydrostatic unit (H) operating as a motor, and further a planetary drive (), a first shaft (W) on the drive side and a summing means (W). The power present at the first shaft (W) is divided by way of the planetary drive () to a mechanical transmission branch (Z, W, Z, Z) and a hydraulic transmission branch (Z, W, Z, Z, Z, H, H) formed by the two hydraulically coupled hydrostatic units (H, H) and is combined again at the summing means (W). In such a transmission, a compact and simplified design and great flexibility in application are achieved in that the power transmission between the first shaft (W) and summing means (W) can be controlled exclusively by varying the displacements of the hydrostatic units (H, H).

Continuously variable hydrostatic transmission having torque division

A hydrostatically power-splitting transmission (), particularly for agricultural and construction equipment, comprises at least two hydrostats (H), which are hydraulically connected to each other and operate as pumps or as motors, wherein at least one of the hydrostats (H) can be adjusted or pivoted by means of a controller (; SK, . . . SK), mechanical coupling means (K, K; Z, . . . , Z), which couple the hydrostats (H, H) to an inner drive shaft (W) and an inner driven shaft (W), a housing () comprising a cover () and a housing bottom part (), wherein the hydrostats (H, H), the inner drive and driven shafts (W, W), and the mechanical coupling means (Z, Z) are disposed and attached on the bottom of the cover (), and in the lower housing part an outer drive shaft accessible from the outside and a driven shaft are supported, which are operatively connected to the inner drive shaft or driven shaft when the housing is assembled. In such a transmission, a compact design, while simultaneously providing easy accessibility and high flexibility in the adaptation to different vehicles, is achieved in that the controller (; SK, . . . SK) for adjustment or pivoting of the at least one hydrostat (H) is disposed on the top of the cover () and acts upon the at least one hydrostat (H) through the cover ().

Hydrostatically power-splitting transmission

A power-branched transmission, particularly for agricultural vehicles such as tractors or similar, includes a stepped planetary gear which is disposed between an input shaft and an output shaft and is used for dividing the power supplied at the input shaft onto a mechanical power branch and a hydraulic power branch. The hydraulic power branch is formed by two hydraulically interconnected, identical hydrostatic axial piston engines which can be selectively operated as a pump or an engine, can be swiveled within a predefined pivoting angle, and can be connected to the input shaft or the stepped planetary gear in a different manner via two respective clutches so as to cover different operating ranges or running steps. In order to obtain better efficiency in such a power-branched transmission, the two hydrostatic axial piston engines are configured as wide-angle hydrostats that are provided with a minimum pivoting angle range of 45&#xb0;.

Power-branched transmission and method for the operation of such a transmission

The invention relates to a hydrostatic axial piston machine having a cylinder block which can be rotated about a first axis, the cylinder block being provided with a plurality of cylinder bores which extend in the axial direction and which are arranged on a partial circle which is concentric in relation to the first axis, in addition to a plane which can be rotated about a second axis, whereon a number of pistons associated with the bores, can be articulated in a pivotable manner on a second partial circle which is concentric in relation to the second axis and form a ring. Also provided is a device for synchronizing the rotation of the cylinder block about the first axis and the drive shaft about the second axis. The cylinder block and the drive shaft can be adjusted in a continuous manner using both axes, between a first position, wherein both axes are parallel, and a second position, wherein both axes together form a maximum pivoting angle which is different from zero.

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Ennetbaden, Switzerland

Markus Liebherr