A liquid ring pump includes a planar port plate having first and second planar walls, a sidewall which defines a shaft receiving aperture, an inlet, and an outlet. An opening is formed in the port plate and includes an open end that extends through the sidewall and an open face that extends through the first planar wall. A rotor shaft is rotatable about a central axis and is positioned such that a portion of the rotor shaft extends into the shaft receiving aperture. An aperture is formed in the port plate and positioned substantially opposite the opening. The opening, a space defined between the rotor shaft and the sidewall, and the aperture, cooperate to define a channel that extends between a first side of the shaft receiving aperture and a second side of the shaft receiving aperture, wherein the channel is formed entirely coplanar with the port plate.

A liquid ring pump includes a port plate coupled to a pump head. The port plate has an opening with a first end at a first section and a second end at a second section. The first section opens through a portion of a surface forming a first face of the port plate. The second section opens at the second end into a shaft receiving aperture of the port plate. The first and second sections are continuous. The first section is angularly between the closing edge of a port plate outlet and leading edge of a port plate inlet. A length measured from the first section to the inlet's leading edge is less than a length measured from the first section to the outlet's leading edge. The first section does not open into the outlet or inlet.

An internal gear pump or motor includes inner and outer rotors that mesh together. An internal electric motor or generator may include a stator supported by a support element that passes through bearings of the outer rotor and the inner rotor may act as a rotor of the electric motor or generator. With or without the stator, the support element may support bearings of the inner rotor. Fluids may be supplied via the support element for cooling, lubrication or to flush a working fluid out of portions of the pump or motor, such as bearings. Flushing may also occur via channels in the housing. Axial faces of one of a pair of adjacent elements may include portions for improved axial sealing and wearing in of the other of the pair. Fluid may enter and exit chambers between the inner and outer rotors by radial ports.

A multiphase pump system includes a pump (10) having first and second screw rotors (4) disposed within a pump body (A), and at least one inlet (3) in fluid communication with the first and second screw rotors, respectively. A discharge casing (B) is coupled to the pump body (A) for receiving fluid discharged from the first and second screw rotors (4). The discharge casing (B) is oriented orthogonally or at a non-zero angle with respect to a longitudinal axis of the pump body (A). The discharge casing (B) includes a separation chamber for separating liquid and gas components of the fluid discharged from the first and second screw rotors (4). The pump body (A) includes at least one opening (9) for directing separated liquid from the discharge casing (B) to a discharge chamber of the pump body (A).