GB1317424A - Electric motor - Google Patents

Abstract

1317424 Electric motors WARD & GOLDSTONE Ltd 6 Jan 1972 [7 Jan 1971 19 March 1971 25 Aug 1971] 764/71 and 39951/71 7267/71 Heading H2A In a motor having a cylindrical housing 10 containing a stator 12 within which is disposed a shaft 26 carrying a rotor and commutator 28, a plastics cup 14 is located in one end of the housing with the base 16 of the cup positioned inwardly of the end, the base 16 having an aperture 42 through which the commutator extends and also carrying spring-loaded brushes engaging the commutator, and the ends of the housing are closed by plastics end caps 18, 20 carrying bearings 24 for the shaft. The commutator comprises L-shaped strips 34 secured on an insulating tube 30 by a washer 38 and a cap 40, and the brushes comprize L-shaped members 50, Fig. 2, pivoted at one end on posts 54 and loaded by springs 56. The end cap 20 may be replaced by a modified cap (20<SP>1</SP>), Fig. 4 (not shown), carrying a rectifier (74) and capacitors which are enclosed by a further end cap (80) fitting over the cap (20<SP>1</SP>). Preferably a metal rectifier with a plurality of elements is used and one or more capacitive plates are provided between and insulated from the elements for reducing sparking at the commutator. In another embodiment, Fig. 5 (not shown), the housing is cup-shaped and the plastics cup (108) clamps the stator against a shoulder (106) in the housing and is prevented from rotating by lugs on a plastics end cap (118) for the housing, which lugs engage recesses in the cup and housing. The end cap (118) may be replaced with one carrying a rectifier as referred to in connection with Figs. 1 and 3.