Hydraulically driven shipboard submersible pump - has chamber between motor and pump under gas pressure to prevent leakage (NL041176)

摘要

The pump has a hydraulic motor (1) with oil supply and discharge connections (22, 23). The motor shaft (8) is extended downwards and carries a centrifugal pump impeller (7) the discharge (6) of which is carried up to the above the top (19) of the liquid container in which the pump and motor assembly is submersed. A chamber (9) in the assembly casing (4) separates the gland (11) of the motor and the gland (10) of the pump. Air under pressure is admitted from a pipe (16) through a non return valve (17) into this chamber and escapes through a smaller outlet (18). The air pressure is higher than that of the oil in the motor and that of the liquid in the pump and thus prevents leakage through both glands.