GB610089A - Improvements in or relating to variable speed transmissions - Google Patents

Abstract

610,089. Hydraulic couplings. BORG-WARNER CORPORATION. Feb. 26, 1946, No. 5959. Convention date, March 21, 1944. [Class 69 (ii)] [Also in Group XXIV] In a variable-speed gear having epicyclic gearing dividing the driving power between a hydraulic torque converter and mechanical power transmitting means, the recombined power passes for further torque modification to a second epicyclic gearing nested within the first. As shown, an intermediate member 31 is powered from planet pinions 24 carried on a driving fly - wheel 22, both directly through an external ring gear 25 on the member 31 and indirectly through an annulus 26 connected by a drum 30 to the impeller 27 of the converter whose turbine 28 is splined to the member 31. The member 31 drives through a one-way clutch 16, the planet carrier 33 of the second epicyclic gear whose interengaging planets 35, one only of which is shown, mesh respectively with an annulus 36 splined to the driven shaft 11 and with a reaction sun 38 connected by a tubular shaft 39 both to a brake 19 and, via a one-way clutch 20, to the reaction element 29 of the converter. An intermediate tubular shaft 44 connects the planet carrier 33 to a second brake 18. For forward running the brake 19 is engaged to station the reaction element 29 and sun 38, the brake 18 being released. A friction clutch 17, described below, gives a lower or higher speed range according as it is freed or, above a predetermined speed of the shaft 11, engaged to connect the member 31 directly to the annulus 36 and cut out the second epicyclic train, the clutch 16 then overrunning. A reverse speed range is provided by releasing the brake 19 and engaging the brake 18 to station the planet carrier 33 and also, via the clutch 16, the turbine 28 and sun 25, the reaction element 28 then rotating backwardly and driving through the now non-planetating gears 35. For neutral, the clutch 17 and both brakes 18, 19 are released. The clutch 17 comprises a cone and disc clutch member 53 slidably splined on the annulus 36 and pressed against a clutch cone 48 on the member 31 by a combined presser plate and piston 52 slidably splined on the member 31. The clutch is engaged against spring pressure by the admission of fluid, supplied by pump means driven by the shaft 11 and monitored by means responsive to the speed of that shaft, to the rear of the piston via shaft passages 64, 63, 60 and a conduit 58. Spring-loaded plungers 67 assist disengagement of the members 48, 53. Converter replenishment is effected through shaft passages 70 ... 72. To allow the shaft 11 to drive the fly-wheel 22, as for push starting of a vehicle engine, a one-way clutch 47 is provided.