GB682272A - Improvements in or relating to centering devices more particularly for engine starters - Google Patents

Abstract

682,272. Torque-limit couplings. BENDIX AVIATION CORPORATION. May 9, 1950 [May 19, 1949], No. 11565/50. Class 80 (ii). [Also in Group XXVII] In a centering member such as a bushing 50 for an engine starter having a spline nut 24 drivingly connected to a surrounding barrel 22 through a torque-limiting friction disc-clutch 26 connected to the spline nut 24 and rotated thereby, there is provided a circumferential surface having a running clearance with the barrel 22 and embodying a slit; the invention also consists of an engine starter comprising an engine engaging member 12 connected to the barrel 22 through the nut 24 located within the barrel, the clutch 26 serving to drive the nut 24 from the barrel 22 incorporating the slit bushing 50. The starter motor is connected to the engine engaging or jaw member 12 through sun gear 16, planetary gearing 18, the barrel 22, clutch 26, axiatlystationary splined-nut 24 and screw-shaft 28, the latter being splined to the jaw member 12 which is engaged by a friction ring 36 and oil seal 38. The guide bushing 50 is provided between the end plate of the clutch 26 and a flange 52 of the nut 24; grease pockets are formed in the face of the bushing 50 abutting the flange 52. The radial slit substantially prevents radial expansion and contraction of the bushing, thereby avoiding binding between the bushing and barrel at high temperatures and ineffective centering of the nut and barrel at low temperatures; the slit width is determined by the temperature coefficient of expansion of the bushing 50.