GB845265A - Improvements in and relating to dynamo-electric machines - Google Patents

Abstract

845,265. Cooling dynamo-electric machine current collecting gear. ENGLISH ELECTRIC CO. Ltd. Oct. 9, 1956 [Oct. 14, 1955], No. 29322/55. Class 35. In a dynamo-electric machine having stationary brush gear co-operating with current collection or delivery means mounted on the rotary member of the machine, gas deflecting means co-operating closely with the current collection means are provided to deflect gas carried around by the latter, away from the latter, when the machine is operating, and thereby cause a continuous change of the atmosphere surrounding the current collection means. As shown, the deflecting means are three curved scoops 34 having air entry portions tangential to and closely adjacent the brush contacting cylindrical surface, and possibly also the vertical surface, of respective slip rings 11 ... 13 forming the collection means and carried by an insulated sleeve 10 mounted on an extension 14 of an induction motor shaft; the air enters a mesh plate covered inlet opening 30a of an enclosure 30 and the scoops deflect the air to discharge radially through a mesh plate covered enclosure opening 30b. For each slip ring there are two groups of five brushes 16 located in brush boxes 17 carried on a respective support ring 18, 19 or 20 which rings are spaced apart by insulating bushes 25 and mounted on three studs 22 ... 24 screwed into bosses 28a of an enclosure back plate 28 secured to extensions 15a on the end 15 of the rotor shaft bearing pedestal. The scoops 34 are near the trailing edges of one brush group and there may be further scoops 37 near the leading edges of the other brush group. The scoops may be of either metal or electrically insulating material, and may be provided instead for cooling the commutator of a D.C. machine. Specifications 321,892, 516,526 and 696,545 are referred to.