GB481715A - Change-speed gear with hydraulic control - Google Patents

Abstract

481,715. Change - speed gearing. BARBAROU, M.J. B. July 10, 1937, No. 19214. Convention date, July 10, 1936. [Class 80 (ii)] A change-speed gear suitable for driving the supercharging compressor of an internal-combustion engine comprises two step-up planetary trains of different ratios brought into action by arresting their annuli 8, 22, Fig. 1, respectively, by moving a double-acting disc brake 17 axially by fluid pressure according to the position of a valve 47 which is moved by hand, or, upon an aeroplane, by a manometer. Separate planet gears 4, 5 of the two gear trains are supported on the same carrier spider 2 fast on a driving- shaft 1. Two corresponding sun gears 15, 30 are fast on a driven shaft 16 and are driven at different relatively-high speeds when the annuli 8, 22 are held. The control ring 17 slides axially on pins 20 and is thrust positively in one and the other direction by two opposed rings of servomotor pistons 32, 33. Fluid under pressure enters by an aperture 44, Fig. 3, and, in the position of the valve 47 shown, passes by a port 42 and annular conduit 37 to behind the pistons 32, so that the annulus 22 is held. When the valve 47 is pulled right of Fig. 3, the fluid passes by a cross duct 48 to an annular conduit 40, Fig. 1, to behind the pistons 33, so that the annulus 8 is held.