Gear type hydraulic pump or motor - has inserts with passages between chambers to equalise pressures for higher loads and efficiencies

摘要

The machine has an externally toothed rotor (1) which meshes with an internally toothed rotor (2). The gaps between the teeth form variable volume working spaces. The rotors are contained in a cylindrical casing with circular endplates and there are inlet and discharge ports in the endplates. The crescent shaped space between the rotors contains an insert (3) and a corrugated dividing wall (56). These divide the space into two low pressure chambers (5,4) and two high pressure chambers (6,53). The chambers of each pair are joined by passages (54) through the insert. This equalises the pressures round the rotors and thus reduces leakage.