GB1411586A - Transmission system - Google Patents

Abstract

1411586 Variable speed gears USTAV PRO VYZKUM MOTOROVYCH VOZIDEL 7 Dec 1972 56605/72 Heading F2D In a variable ratio gear for automotive vehicles the turbine 3 of an hydraulic torque converter, of which the impeller 2 is driven by the input shaft 1, is connected by a tubular shaft 7 and reduction gearing 6, 22, 8 to a tubular shaft 20 and sun-wheel 9 of an epicyclic train, a second sun-wheel 15 of which is driven by a shaft 16 which is connectible by a clutch 18 either with the input shaft, as shown, or, in a modification, with the turbine 3, the planet carrier 13 of the epicyclic train drives the output shaft 14, and a ring gear 10 may be held by a brake 21 for selecting reverse ratio. Both the reaction member 4 of the converter and a carrier 17 for the pinions 22 are connected to the gear casing by over running clutches 5, 19. For low ratio a clutch 12 is engaged to lock the carrier 13 to the shaft 20, and power is transmitted through the turbine 3 and reduction gearing 6, 22, 8. Engine braking may be effected in this ratio by applying a brake 11. Intermediate ratio is established by releasing the clutch 12 and engaging the clutch 18, when power is transmitted partly through the shaft 16 to the sun-wheel 15 and partly through the turbine 3, reduction gearing 6, 22, 8, and the sun-wheel 9. Engine braking is also available in this ratio if the brake 11 is applied. High ratio is direct, established by engagement of both clutches 12, 18, and reverse is obtained by engagement of the brake 21. In the modification referred to above, in which the clutch 18 connects the shaft 16 with the turbine 3 instead of with the input shaft 1, four forward ratios are provided, low being obtained by engaging the clutch 18 and brake 21, and second, third and fourth corresponding to first, second and third in the three-speed version. In another modification, the clutch 12 is connected to the shaft 20 through an overrunning clutch, and a friction clutch interconnects the planet carrier 13 and the ring gear 10. This arrangement simplifies control by allowing upshifts from first to second speed to be effected without disengagement of the clutch 12, and third speed to be established by engagement of the clutch between the carrier 13 and ring gear 10. In further modification, suitable for front-drive or rear-engined vehicles, the input shaft 1 extends to a clutch 18 inside the gearbox, the output from this clutch and that from the turbine 3 are transferred by gears to coaxial shafts whose axis is parallel to and below that of the shaft 1, and on which are mounted the sunwheels 15, 9, and through which the output shaft 14 passes to a final drive location between the torque converter and the gear-box.