Patent GB-458591-A (GB)
Title: Improvements in or relating to variable speed gearing
IPC: F16H3/66
Filed: 1935-05-15
Abstract: 458,591. Hydro-mechanical and planetary variable speed gearing. PROPELLO INVENTIONS, Ltd., 105, Cheyne Walk, Chelsea, London, and YOXALL, J., York House, Deganwy, Carnarvonshire. May 15, 1935, Nos. 14256/35, 32897/35, 11089/36, and 12544/36. [Class 80 (ii)] A variable-speed transmission gear comprises in combination an hydraulic coupling such as 5, 9, Fig. 4, and a series of compounded epicyclic trains O, S, F, R in which an element such as 148 of an overdriving train O is adapted to be connectible at will with another rotatable element of the combined transmission to effect a substantial direct drive, and alternatively to be held by a brake 56 to effect an overdrive. In the arrangement of Fig. 4, the other rotatable element engaged for the direct drive is the driving member 5 of the hydraulic coupling. That is, for direct drive reduced by slip in the coupling, the element 148 is connected by a friction clutch 31, 32 to the member 5 so that power passes to the element 148 without passing through the coupling. On the direct drive there is a branching of the power circuit, part passing through the coupling, as described in Specification 440,650, in this case through an intermediate shaft 21 to the carrier 147 of the overdriving train O. The overdrive is thus imparted at will to a shaft 123 so that the overdrive and the direct drive can be combined with each of the reduced speeds obtained by braking the trains F and S for first and second reduced speeds. The train R effects reversed driving of a driven shaft 52 in combination with the train F. There is described with reference to Fig. 1 (not shown), an arrangement in which the carrier 147 of Fig. 4 is driven from the driving member 5 of the coupling instead of from the driven member 9. Fig. 2 shows an arrangement in which the overdriving train O is arranged between the first and second speed trains F and S. During direct drive the sun gear 148 of the train O is clutched at 103 to the carrier 147 of the same train which turns solid as does also the train S which is clutched solid through the coupling 5, 9 at 31, 32. The power branches, part passing through the hydraulic coupling to a shaft 21 and part passing through a sleeve 16 to the clutch 31 without passing through the said coupling. For overdrive, the gear 148 is held fast by a brake 63 upon a drum 62. Carriers 47, 147 are rigidly connected. The brakes and clutches are operated through suitable hydraulic cylinders controlled from a selector valve as in the arrangement described in the Specification referred to. The oil is circulated by a pump driven by an eccentric 45 fast on the sleeve 16. Fig. 3 shows an arrangement in which the power passes without branching to a shaft 21 which is the driving-shaft of the mechanical multipletrain unit. There are trains O, S, F, R as in the other arrangements, and an intermediate shaft 123 which is driven at two speeds through the overdriving train O as in the arrangement of Fig. 4. For direct drive, the train O is clutched solid at 31, 32 ; for overdriving, the clutch 31, 32 is opened and the sun gear 48 held fast by a brake 56. Specification 440,649, [Group XXXIV], also is referred to.