Patent ID: 6758660
Filing Date: 2004-07-06
Classification: F04C,F16H

Abstract:
A screw vacuum pump comprising:two interengaging rotors, each rotor defining a central hollow chamber; two shafts, each shaft being received in one of the rotor central hollow chambers with a narrow, annular cooling slot segment being defined between the shaft and the rotor and extending between a suction side and a discharge side, the shafts each defining a feed line which feeds coolant oil to the annular cooling slot and a discharge line which discharges the coolant oil from the annular cooling slot; the annular cooling slots each having a thickness which is sufficiently thin that the boundary/flow layer of the cooling coil flowing along a shaft side surface of the annular cooling slot influences a boundary flow layer of the coolant coil flowing along a rotor side surface of the annular cooling slot in a turbulent manner.