ARRANGEMENT FOR THE EVACUATION OF AIR FROM CANNED MOTOR PUMPS

摘要

1315032 Electric motors LOEWE PUMPENFABRIK GmbH 30 June 1970 [22 July 1969] 31670/70 Heading H2A In a motor-pump assembly, particularly for circulating water in central heating systems, in which the motor is of the "canned" rotor type, air is extracted from the rotor space through a duct 18 in the rotor shaft which is closable by a valve 19 actuated automatically by the liquid when the rotor space is full to prevent further blow from the rotor chamber and the risk of impurities being carried through the bearings to the rotor chamber. The duct 18 communicates with the rotor space by a radial passage 20, Fig. 4 and the valve 19 may comprise a strip of resilient material such as rubber or plastics material clipped round the shaft by a spring 25 and having a free end which is pressed over the passage 20 by water pressure as the rotor space fills. Alternatively the valve may comprise a spiral spring or a ball (24), Fig. 8 (not shown), co-operating with an aperture (23) in a cap (22) at the impeller end of the duct 18.