Gear pump or motor - has housing with cylindrical wall, containing curved bearing shells rolling on housing wall

摘要

The pump or motor has a housing with an inlet and outlet for the passage of the delivery or working medium to the housing cavity. This contains a pinion, meshing with an internally toothed hollow gear and a crescent-shaped filler piece, the latter enclosing a relatively small low pressure chamber. The housing wall (13) is cylindrical, with its radius (RG) larger than the external radius (RH) of the hollow gear (2). - The annular space (3) round the hollow gear contains arched bearing shells (7,8) with inner surfaces (9,10) engaging the gear. The outer surfaces (11,12) of the shells have a curvature (A) which permits a rolling movement on the wall of the housing. The shell nearest to the low pressure chamber (34) has sealed low pressure sections (16,20), while the other shell is surrounded by high pressure. PS(1/5)