GB1279610A - Improvements in motor vehicle transmissions - Google Patents

Abstract

1279610 Motor vehicle transmission gearing; mounting differential gearing MASSEY-FERGUSON-PERKINS Ltd 9 Oct 1969 [24 Oct 1968] 50507/68 Heading B7H A motor vehicle, e.g. a tractor, includes a transmission in which a transfer gear-box 6 is connected to the casing of a variable ratio gearbox 5 and receives drive therefrom at an upper level while giving output at a lower level to the vehicle rear wheels via a first differential gear between the rear wheels and to the front wheels via a second differential gear, mounted between the front wheels, and a disengageable coupling, the second differential gear having its casing pivotally mounted about a fore-and-aft axis of the vehicle. A support member (3) (Fig. 1, not shown), connected to the engine (2) and the casing of gear-box 5 supports the casing of the second differential gear for pivotal movement about the aligned axes of the differential drive shafts 38, 44. A sliding spline coupling 46 enables the output shaft 43 of the transfer gear-box 6 to be coupled to the front drive shaft 38. The transfer gear-box 6 also transmits the power take-off drive from a shaft 49 to a rear p.t.o. shaft 53 via gears 50, 51 and 52, the gear 51 being journalled on a fixed member 65. A front p.t.o. shaft (not shown), may be coupled to shaft 53 by first removing a cover 54. Drive shaft 38 for the front differential has a splined connection with the differential drive pinion shaft (34) (Fig. 2, not shown). The front differential casing (24) is pivotally supported on the support member (3) by trunnions (22, 23). In a second embodiment (Fig. 4), the transfer gear-box includes a differential gear 66 which can be coupled to the shafts 38, 44 in various ways to provide different drive modes. The gear 42 is integral with a cage 70 having a pair of cage pinions 71 meshing with output gears 73, 75 on shaft 44 and shaft 77, respectively, the latter being optionally connectible to shaft 38. A coupling 80 is movable axially to occupy any one of four positions, under the action of a selector 84. In the first position, as shown, stub shaft 77 is locked against rotation with the result that drive passes to the rear wheels only; in the second position the cage 70 and shaft 77 are locked together providing a 1 : 1 ratio drive to the rear wheels only; in the third position the differential 66 is locked and shaft 77 is coupled to shaft 38 to transmit both drive to front and rear wheels; and in the fourth position is differential 66 is unlocked permitting a differential drive between the front and rear differential gears.