| 摘要 |
Drive system for a water pump unit (7, 8) driven by the shaft of a reversible motor (4) through a partition wall, about said shaft (5) being mounted a first sealing ring (14) fixed to said wall (13), and a second sealing ring (15) rotatably driven by the shaft and forming a rotatable water-tight sealing arrangement (6) with the first ring (14). The system comprises control means (19, 22) capable of normally actuating the motor according to a preset programme, and means (19, 20, 26) to make the motor temporarily oscillate at a predetermined frequency (f), with a sequence of rotations in alternate directions, in case the two sealing rings (14, 15) are stuck together. The oscillation of the rotatable unit associated with the rotor (5) causes the two sealing rings to mutually separate. <IMAGE> |
