Patent ID: 6569047
Filing Date: 2003-05-27
Classification: B28C,F16H

Abstract:
A drive device incorporating a hydraulic motor and a planetary reduction gear, the motor comprising a housing inside which is disposed a cylinder block with radial pistons, the device comprising means for coupling between the output of the motor and the input of the reduction gear, the reduction gear comprising a housing inside which is disposed a planetary reduction gear system and having an output provided with means for driving in rotation, the housing of the motor and the housing of the reduction gear forming distinct enclosures, each having an interior, and the drive device comprising means for allowing a circulation of fluid between said interiors of said housings and for controlling this circulation of fluid by allowing a limited circulation of fluid at least in one direction of circulation between the interior of the housing of the motor and the interior of the housing of the reduction gear, as a function of a difference in fluid pressure between the respective interiors of said housings.