GB464570A - Improvements in or relating to variable-speed gears especially suitable for motor-vehicles and locomotives - Google Patents

Abstract

464,570. Speed - varying mechanism. SWAN, J. G. July 17, 1935, Nos. 20323 and 29306. [Class 69 (ii)] [Also in Group XXIV] Change-speed gearing including an hydraulic torque converter T has in,parallel therewith a planetary gear train P through which a direct drive may be effected to supersede the drive through the converter, by engaging a friction clutch 88, 89. An hydraulic coupling C shown may be omitted or replaced by a centrifugal mechanical clutch. A member 62 fast on an input shaft 61 carries the pump element 51 of the converter, the primary element 55 of the coupling, and the friction clutch element 88. The turbine element 52 of the converter T is fast on a spool 72 rigid with the output shaft 71. The reaction element 53 of the converter is rigid with a hollow shaft 75 carrying a brake drum 77 and rigid at 91 with the carrier 82 of planets 84 of the train P. The annulus 81 of the train P is rigid at 78 with the secondary element 56 of the coupling C. The sun gear 85 of the train P is on a sleeve 90 carrying the clutch member 89 and a brake drum 87. In starting from rest, the drum 77 is held and a torque increasing converter T drives the shaft 71 slowly, the sun gear 85 being free. When the load shaft 71, which may be the propeller shaft of a vehicle, accelerates, the drum 77 is released to free the converter and the drum 87 held so that the drive is through the coupling C to the annulus 81 and through the carrier 82, hollow shaft 75, reaction member 53, and a one-way clutch 94 to the shaft 71, which is thus driven faster at about three-quarters of the speed of the shaft 61, the converter acting somewhat as a coupling. To engage the direct drive the drum 87 is released and the clutch 88, 89 engaged. The train P then turns solid and the shaft 71 is driven through the one-way clutch 94. Oil can circulate between the coupling and the converter by ducts 96, 97. An oppositely-set one-way clutch 95 is used for braking by the engine. A modification is described with means for readily changing between the converter drive and the direct drive. Specification 439,664 is referred to.