US 5,328,418 AGranted

Stepless hydromechanical mechanism with multiple power-transmission paths, more particularly for motor vehicles

OwnerMichael Meyerleinventor

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Abstract

Stepless hydromechanical mechanism with multiple power-transmission paths, more particularly for motor vehicles, having at least two switching ranges in which the stepless control of the mechanism is effected by a hydrostatic transmission, in which the specific requirements on the hydrostatic unit are reduced to a minimum. The hydrostatic power content is reduced. The parameters determining noise, efficiency and service life, i.e., hydrostatic pressure, hydrostatic speed, as well as the values of these components and their arrangement are brought into acceptable and technically feasible bounds. To this end, two summation planetary gearing mechanisms are provided in which the input shaft of the transmission is drivingly connected to a first hydrostatic unit and to a first inlet shaft of the first summation planetary gearing mechanisms, and a second hydrostatic unit is connected to a second inlet shaft of the first summation planetary gearing mechanism and to a first inlet shaft of the second summation planetary gearing mechanism.

Claims25

Dependent claims

A stepless hydromechanical transmission having a power input shaft, a power output shaft and a multiple path power transmission mechanism for transmitting power in at least two hydrostatic-mechanical forward shift ranges from said input shaft to said output shaft, said power transmission mechanism comprising:

a hydrostatic drive unit, said hydrostatic drive unit comprising a variable speed drive section which is drivingly connected to said power input shaft and a driven section having a hydrostatic power outlet shaft;
a compounding summation planetary gear unit having at least five shafts and comprising first and second summation planetary gearing sections that are continuously drivingly interconnected by at least two shafts,
said summation planetary gear unit having a first shaft that is in continuous driving connection with said power input shaft and a second shaft that is in continuous driving connection with said hydrostatic power output shaft,
said hydrostatic power outlet shaft being in continuous driving connection with both of the summation planetary gearing sections,
said mechanism being arranged such that in the initial starting stages of the first of said forward shift ranges said first and second shafts rotate in the same direction, and in a later stage of said first shift range said first and second shafts rotate in opposite directions.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/135,759Filed 14 Oct 1993 · continuation
Priority: DE 353319118 Sep 1985
Granted: 12 Jul 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

F16H 47/04
The fluid gearing being of the volumetric type: the mechanical gearing being of the type with members having orbital motion
F16H 2037/0886
Power-split transmissions with summing differentials, with the input of the CVT connected or connectable to the input shaft: with switching means,…
F16H
Gearing

Family

Serial906,826Parent of this continuation · filed 12 Sep 1986
Serial277,450Parent of this continuation · filed 28 Nov 1988
Serial481,796Parent of this continuation · filed 20 Feb 1990
Serial551,055Parent of this continuation · filed 11 Jul 1990
Serial758,488Parent of this continuation · filed 9 Sep 1991
Serial920,171Parent of this continuation · filed 27 Jul 1992
US 5,328,418 AThis patent

From the US filing history. Foreign family members aren’t listed.