GB1509880A - Transmission for tractors - Google Patents

Abstract

1509880 Change speed gearing; clutches; friction gearing KUBOTA Ltd 21 Sept 1976 39144/76 Headings F2D F2C and F2Q A transmission for a tractor comprises an input shaft 8, driven from an engine flywheel 7 through a shock-absorbing coupling 11, the input shaft having three gears 9 in mesh with gears 21, 22 and 23, selectively clutchable by radially movable pins 36 to a propelling speedchange shaft 15, and also in mesh with three gears 24, 25, 26 selectively clutchable by pins 36 to a power take-off shaft 16. The propelling speed-change shaft 15 is coupled to a shaft 50 either directly or through a friction planetary reduction gear 40 (Fig. 7) whose sun gear 51 is driven by shaft 15 and whose planet carrier 49 is clutchable to shaft 50 by a sleeve 55, which sleeve can also directly connect shafts 15 and 50. A differential 62 for the rear wheels of the tractor is driven through a two forward speed and reverse gear-box whose output shaft 58 drives the differential through gears 63, 60. The front wheels of the tractor may also be driven from shaft 58 through gears 73, 80 and 78 and a shaft 82, the gear 78 being axially movable to connect or disconnect the drive. The clutches for engaging the gears on shaft 15 are shown in Figs. 3 and 4 (those for shafts 16 and 58 being identical) and comprise pins 36 spring-biased, by springs 35, out of engagement with recesses 39 of the gears and moved by a land 29 of an axially movable selector rod 27 (this being the selector for shaft 15) to engage a gear. The rod 27 acts on pins 36 through balls 37 and the recesses 39 are shaped to reduce shocks on engagement, which shocks are also absorbed by resilient coupling 11 (Fig. 2). The friction planetary gear 40, shown in Fig. 7 has a metal sun gear 41, a fixed metal ring gear 42 and planet gears 43 comprising inner and outer metal sleeves 44, 45 with resilient material (e.g. rubber) 46 between them. The planetary gear 40 slips on exess torque being transmitted.