GB191209982A - Improvements in Variable Speed Gearing. - Google Patents

Abstract

9982. Douglas, J. A. April 26. Variable-speed epicyclic gearing comprises an arrangement of spur and bevel toothed wheels which gives a continuously-variable velocity ratio. The speed is varied by varying the eccentricity with respect to alined driving and driven shafts 5, 6, Fig. 1, of a bevel reversing- gear 42, 48, 43, as shown in Fig. 2. A frame 8 consisting of rectangular members 10, 11 at right-angles to one another is secured to the shaft 5. A gear 14 is secured to a fixed frame 2. A like gear 25 is secured to the shaft 6. Other like gears 40, 41 are connected by the reversing-train 42, 48, 43. The gears 14, 40 are engaged by toothed planetary wheels 31, 32, which are secured to a spindle 29 carried by the frame 8. The gears 25, 41 are engaged by like wheels 34, 33 secured likewise to a spindle 30 also carried by the frame 8. When the axis of the gears 42, 43 is in line with the shafts 5, 6, and the frame 8 revolves, the motion of the gear 25 is necessarily zero, corresponding exactly with the motion of the fixed gear 14. As the axis of the gears 42, 43 is gradually moved into more and more eccentric positions, the gear 25 is driven at a graduallyincreasing speed. For this purpose a spindle 39 carrying the bevel-train 42, 48, 43 is carried upon arms 37, 38 extending from wheels 35, 36 which are loose on the spindles 29, 20, respectively, and are equal in size to the planetary wheels 31 &c. The position of the spindle 39 is controlled externally in the following manner. The wheels 35, 36 are connected through loose central gears 16, 27 and other gearing 51, 52, &c. to a spindle 59, Fig. 1, and thence through a radial spindle 63 to a pin-wheel 67. The wheel 67 is adapted to be engaged and driven alternatively by oppositely-acting spiral threads upon non-rotary disks 22, 23 upon a sliding sleeve 20. The gear 48 is kept from turning end-over - end by a trailer 46 engaged by a circular raceway 12 carried by the frame 8.