Abstract: Liquid-ring gas pump with a working space containing an overhung impeller (17) and a connection casing (2) which is separated from the working space by a control plate (13). This casing contains, on one side of a hub space (11) suitable for the accommodation of a mechanical seal (12), an inlet space (5) and, on the other side, a discharge space (6). The discharge space is connected to the working space to allow the recirculation of recirculated liquid. The connection between the discharge space and the working space is passed via the hub space. The hole (19) connecting the discharge space to the hub space is expediently situated on an extension (18) of the discharge space (6), the said extension leading across to the side of the pump containing the inlet space.

Abstract: Single-stage liquid ring gas pump which can be flanged to a drive unit. The suction and delivery connections are disposed on a connection casing (3) which is to be connected to the drive unit. On the side of the connection casing remote from the drive are disposed a plate cam (4) and a working chamber casing (5) together with the impeller (14) rotating in the latter. The impeller sealingly cooperates on its open end face with the plate cam and on its largely closed end face (19) with an end wall (7) of the working chamber casing (5). The working chamber casing is in the form of a deep-drawn sheet metal part and has no medium connections. For the purpose of connection to the connection casing or the plate cam, it is provided with a radial connection flange (6). The transition from the cylindrical part to the connection flange (6) of the working chamber casing (5) is rounded on the inside such that the gap remaining between this rounding and the plate cam remains below a particular size.

Abstract: Liquid-ring gas pump with a working chamber in which an impeller (6) rotates and which is bounded axially by a control plate (7) past which the impeller (6) moves with a small clearance and which has at least one intake and/or discharge opening (21, 22, 23) and is composed of rolled sheet. According to the invention, the edges (26) of the intake and discharge openings are at least in part bent over towards the side facing away from the impeller (6) and are rounded on the side facing the impeller and raised on the side facing away from it.