GB832610A - Improvements in commutating dynamo-electric machines - Google Patents

Abstract

832,610. Dynamo-electric machines. METROPOLITAN-VICKERS ELECTRICAL CO. Ltd. Aug. 2, 1956 [May 4, 1955], No. 12980/55. Class 35. A commutating dynamo-electric machine such as a turbo-alternator exciter has a plurality of brush sets each including a brush box carrying lever 8 pivotally journalled on a shaft 4 carried by the stator and the lever is displaceable between a normal operative position (top of Figure) determined by a fixed positioning means carried by the stator and a retracted position (bottom of Figure) wherein the brush box 20 is away from the commutator 1 and is more readily serviced, together with a flexible electrical cable 48 interconnecting the brush box and electrical plug means 47 normally plugged into a fixed complementary electrical connector 44 which is separate from the brush box and is carried by the stator. The positioning means comprises a bar 43 extending between rocker rings 6 (not shown) and 2, and having an adjustable screw stop 42 engaged by a lever tail 41. The lever 8 is held in the operative position by a nut 37 on. a threaded spindle 38 in a slot 40 of another bar 34, and in the retracted position by inserting in the slot 40 the portion of the spindle 38 between nuts 38, 38a. Brush pressure is exerted by a spring 27 acting through curved blades 23 and the brush box 20 is adjustably secured by bolts 31 to a casting 11 having openings 16, 17 which direct to the commutator 1 air flowing axially of the armature. The connector 44 comprises a bus-bar enclosed in insulating material 45, 46 and carried by the bar 43. Each brush box may carry one or more brushes 22, one or more brush sets may be carried on each shaft 4 and in the case of two sets may be alternatively withdrawn for brush inspection from the commutator, and diametrically opposite bus-bars may be electrically interconnected.