GB765951A - Improvements in or relating to one-way clutch assemblies particularly for engine starters - Google Patents

Abstract

765,951. Turning-gear. UNITED AIRCRAFT CORPORATION. March 17, 1955 [March 24, 1954], No. 7801/55. Class 7 (5). [Also in Group XXIV] In a engine starter drive having a positive one-way clutch 74, 92 engaged without substantial rotational movement for connecting a ring gear 64, driven by a gas turbine 26 through double reduction gear 42, 44, 48, 64, with a shaft 18 of the engine to be started, the positive clutch comprises a facially ratchettoothed driven member 92, fast with the engine shaft 18, and a complementary driving member 74, connected externally by a left-handed helical spline 72 to the ring gear 64 and internally by a right-handed helical spline 76 to an inner shaft 82 having a forward-drive one-way roller clutch connection 108 with the clutch output member 92. On initial rotation, clockwise from left, clockwise torque, applied to the inner shaft 82 by the ring gear 64 through the double splines 72, 76, is resisted by reaction of the one-way clutch 108 on the stationary engine shaft 18, causing the driving clutch member 74 to screw axially to the right on its internal right-hand spline 76, into toothed engagement with the output clutch member 92 without rotation, which latter follows through the outer left-handed spline 72 on complete engagement. The clutch teeth 78 are sawtoothed with trailing flank angles matched to the angle of the right-hand helix 76. If initial toothed engagement is only partial, engagement is completed by the outer left-hand spline 72, with overrun in the roller clutch 108. If initial engagement is prevented by butting of the top lands of the clutch teeth, the inner shaft 82 is screwed axially to the left against springs 84, 106 with accompanying clockwise rotation of the driving clutch member 74, permitting engagement of the clutch teeth to begin and continue as before. The output member 92 has an oil-slinger ring 98, and the starter construction is generally as also described in Specification 740,845.