Gear-type positive-displacement machine

摘要

A gear-type machine whose housing accommodates two symmetrical idle gears which are in mesh with an internal toothing of an element embracing them inside the housing and with an external toothing of a central gear, whereas the spaces confined between the idle gears and the toothings accommodate webs to form herewith fluid tight chambers for a working fluid which thus imparts rotation of the idle gears. The internal toothing is stationary and carries the webs, while the idle gears are free to roll over the stationary toothing to impart rotation to the central gear which, in turn, may transmit the torque to a machine output member. In another, preferred embodiment, the central gear is stationary while the housing with its internal toothing is rotatable and constitutes the output.