GB829842A - Improvements relating to variable speed power transmission arrangements - Google Patents

Abstract

829,842. Variable-speed gearing. DAIMLERBENZ A.G. Oct. 9, 1957 [Oct. 13, 1956], No. 31556/57. Class 80 (2). In a variable-speed transmission, particularly for motor vehicles, in which a hydro-dynamic clutch 6 is arranged in series with two planetary trains 11, 20, the driven portion 9 of the hydrodynamic clutch being fast with the sun-wheel 18 of the first train 11, and the planet-wheel carrier 19 of the first train serving to drive the second planetary train in all forward speeds, a releasable mechanical clutch 14 is provided between the driving portion 7 of the hydrodynamic clutch 6 and planet carrier 19 of the first train or, alternatively, the sun-gear 18. This clutch is arranged outside the casing 4 of the hydro-dynamic clutch 6 and adjacent the first planetary train 11. For starting and the lower gears the clutch 14 is released so that the drive is from the turbine wheel 9 of the hydrodynamic clutch to the sun-gear 18 of the first train, the annulus 21 of which is braked at 24. Two speeds of the carrier shaft 28 of the second train are obtained by either applying brake 25 or solid drive clutch 26. Two higher speeds are obtained by engaging the clutch 14 of the first train which by-passes the hydro-dynamic clutch 6 and drives the carrier 19 direct. For reverse the brake 15 is applied to hold the carrier 19 of the first train, the clutch 14 being of course released. In the alternative arrangement of the clutch 14 between the impeller 7 of the hydro-dynamic clutch 6 and the sun-gear 18 engagement of this clutch merely cuts out the hydraulic clutch 6 and drives the sun 18 direct from the impeller 7, the annulus 21 being held to still provide a reduction through the first train. Primary and secondary oil pumps 12 and 29 are provided for actuation of the brakes and clutches.