GB423302A - Improvements in and relating to variable speed gearing - Google Patents

Abstract

423,302. Variable speed epicyclic gearing. PITZ, H., 10, Gneisenaustrasse, Saarbr³cken, Germany. May 30, 1933, No. 15615. [Class 80 (ii)] Variable-speed gearing of the kind in which a planet gear 12 drives a sun gear 13, and in which the planet gear is restrained by fluid means, is adapted to yield an overdrive. The planet gear 12 is fast on a shaft 11 adapted to drive a pump in a casing 10 rigidly secured to a frame 9 which is supported at its ends on cranks 7, 8 on parallel shafts 2, 6 which are connected by gearing 4 and driven by a motor 1. The frame 9 is thus caused to wabble round the driven shaft 14 so as to maintain the gears 12, 13 in mesh. The greater the resistance of the pump in the casing 10, the less the slip of the gear 12, and the greater the speed of the shaft 14. This pump draws oil through a cranked pipe 17 from a reservoir 15 and drives it through a cranked pipe 20. Some of the oil returns past a throttle valve 25 to the reservoir 15. An adjustable proportion of the oil is driven through an accumulator 26, which produces back-pressure, past a valve 27 to an hydraulic motor 29 by which means the energy absorbed by the planetary pump 10 is returned to one of the driving-shafts 6. A freewheel 32 allows the motor 29 to be shut off by the valve 27 without interfering with the drive. Exhaust oil from the motor 29 returns by a pipe 30 to the reservoir 15. When the pressure of the oil in the exhaust pipe 20 from the pump 10 builds up sufficiently, a piston is moved in a cylinder 37 which moves a lever 40 to engage a clutch 42 on the shaft 11 with the pump casing 10. The planet gear 12 is thus prevented from turning about its axis and as it is carried round the sun gear 13 drives the latter faster than the shaft 2 of the driving motor 1.