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An integrated hydrostatic transaxle having a common housing for a hydrostatic transmission and a pair of oppositely-extending differentially-connected axles to have the common housing provide a common sump therefor and with a specifically-shaped center section interconnecting the pair of hydraulic d

An integrated hydrostatic transaxle having a common housing for a hydrostatic transmission and a pair of oppositely-extending differentially-connected axles to have the common housing provide a common sump therefor and with a specifically-shaped center section interconnecting the pair of hydraulic displacement units constituting the hydrostatic transmission. The center section is a unitary member separate from the common housing, with the exterior thereof exposed to the common sump. The center section has passages and arcuate ports which are interconnected by certain of said passages and which are located whereby the center section may be cast to minimize any machining required to finish the center section. Such casting can result in a porous center section with possible leakage from a passage having high pressure fluid. However, such leakage is not a problem since the leakage would not be through the wall of the common housing but to the common sump within the common housing which is at atmospheric pressure because of the center section being separate from the common housing.

대표청구항 ▼

In combination, a hydrostatic transmission comprising a pair of hydraulic displacement units, each having a rotatable cylinder block with reciprocal pistons, and a housing for said displacement units providing a fluid sump, said rotatable cylinder blocks having their axes of rotation generally norma

In combination, a hydrostatic transmission comprising a pair of hydraulic displacement units, each having a rotatable cylinder block with reciprocal pistons, and a housing for said displacement units providing a fluid sump, said rotatable cylinder blocks having their axes of rotation generally normal to each other, a one-piece generally L-shaped center section positionable in said housing and having first and second face generally at right angles to each other, said center section being positioned to have said first face engage an end of one rotatable cylinder block and the second face engage an end of the other rotatable cylinder block, arcuate fluid ports at the first and second faces of said center section for coaction with said rotatable cylinder blocks, a first straight fluid passage in said center section connecting one of the ports at each face to define a first pair of fluid communicating ports and terminating at one of said pair of ports, and a second straight fluid passage in said center section connecting another of the ports on each face to define a second pair of fluid communicating ports and terminating at one of the ports of said second pair.