GB578700A - Improvements in or relating to variable-ratio drive or coupling mechanism - Google Patents

Abstract

578,700. Variable-speed gearing. CROSS, E. J. (Watson, S. C.). Jan. 31, 1944, No. 1784. [Class 80 (ii)] A two-element hydraulic coupling 18, 32 is combined with an epicyclic train 21, 43, 51 having worm-type gearing, a one-way brake being provided to prevent reverse rotation of the runner of the coupling. Another train 99, 91, 67, is provided in series so that slip in the coupling produces a double reduction of speed on the driven shaft 76. The driving shaft 1 carries the impeller 18 of the hydraulic coupling and also the sun gear 21 of the first epicyclic train. The runner 32 of the coupling is connected through a sleeve member 25 to the planet carrier 41 of the first train which is in turn connected to the annulus 67 of the second train. The annulus 51 of the first train is connected to sun 99 of the second through casing 49 and sleeve 98 whilst the planet carrier of the second train is integral with the driven shaft 76. Reverse rotation of the runner 32 of the coupling, the planet carrier 41 and the annulus 67 is prevented by a one-way brake 110. In operation for light loads no slip in the coupling occurs and both trains rotate solid for direct drive. On increase 'of load the runner of the coupling slips and the speed of the annulus 51 of the first train is reduced through planetary action-so that a reduced speed is imparted to both sun and annulus of the second train giving a double reduction of the driven carrier and shaft 76. In the extreme case of a very heavy load the runner is stopped and held against backward rotation by the one-way brake, as is also the carrier 41 and annulus 67. The annulus 51 is driven through the worm planets at a reduced speed in the same direction of rotation as sun 21 to drive the shaft 76 at a very reduced speed through sun 99.