GB251237A - Improvements in or relating to electric machines for working under liquid - Google Patents

Abstract

251,237. Siemens - Schuckertwerke Ges. April 27, 1925, [Convention date]. Addition to 242,660, [Class 35, Dynamo-electric generators &c.]. Controlling; driving gear.- In an enclosed motor for working under liquid and having a sump for the collection of liquid which may leak into the casing, as described in the parent Specification a device is provided for automatically starting the sump-emptying pump when the liquid reaches a certain level. in the sump and stopping the pump when the liquid falls below that level. The coupling device shown consists of a fluid friction clutch K, the two elements 6, 11 of which are fast on the shaft 5 of the motor M and the pump shaft 10 of the pump P. The pump draws water from the sump S at 1 and discharges it through an, outlet pipe 4 having a non-return valve 3. The pump members 6, 11, Fig. 2, have oppositelydirected teeth 8, 13, and entry of water between these teeth gives a frictional drive between the shafts 5, 10. The member 11 has outwardlydirected ports 18 and radial bores 19 which are continued through the annular enclosure 14 secured to the member 11 by spring pins 16. The member 6 has ports 9 leading from the inner chamber to the space between the teeth 8, 13. When the water rises sufficiently in the sump it passes through the bores 19 and ports 18 into the space between the teeth until it is high enoughto give a frictional engagement between the teeth and start rotation of the member 11 and the pump. Thereafter, water is thrown centrifugally between the teeth through the ports 9 by the ports 18 and full driving power is obtained until' the pump has lowered the water level sufficientlyto disengage the clutch.