Compressor

摘要

A compressor housing defines a gas inlet flow path and a gas outlet and a rotatable impeller wheel between the gas inlet flow path and the gas outlet. An inner wall of the housing defines a surface in close proximity to radially outer edges of impeller wheel vanes that sweep across the surface as the wheel rotates. An opening is provided in the inner wall at the surface. A port is provided in the housing in gas communication with the opening for diverting gas in a direction away from the inlet flow path during relatively low flow conditions. A gas displacement device is disposed outside of the inlet flow path and connected to the port, wherein the pump is operable to remove gas selectively through the opening and the port in a direction away from the inlet flow path.

主权项

1. A compressor comprising:
a housing defining a gas inlet flow path and a gas outlet; an impeller wheel having a plurality of vanes and mounted in the housing between the gas inlet flow path and the gas outlet, the wheel being rotatable about an axis; the housing having an inner wall defining a surface located in close proximity to radially outer edges of the impeller vanes which sweep across said surface as the impeller wheel rotates about its axis; at least one opening in the inner wall at the surface; a port in the compressor housing in gas communication with the at least one opening and for diverting gas in a direction away from the gas inlet flow path during relatively low gas flow rate conditions; a gas displacement device disposed outside of the gas inlet flow path and connected to said port, the gas displacement device being operable to remove gas selectively through the at least one opening and the port in a direction away from said gas inlet flow path; and a valve that is selectively operable between an open position in which gas is permitted to flow through the port to the gas displacement device and a closed position in which such flow is interrupted; wherein the gas displacement device has an inlet and an outlet and the valve comprises a housing in which a valve member is movable, the valve housing having a first port in communication with the gas displacement device inlet, a second port in communication with the gas displacement device outlet, a third port in communication with a gas flow path through the compressor housing gas inlet and a fourth port in communication with the port in the compressor housing, the valve member being movable to a third position in which permits gas communication between the first port and the third port and gas communication between the second port and the fourth port so that gas may be removed from the compressor gas inlet and discharged to the port in the compressor housing.