GB878930A - Improvements in or relating to counterrotating gear transmission - Google Patents

Abstract

878,930. Change-speed and reverse gear; friction clutches. GERST, C. April 20, 1959 [May 19, 1958], No. 13436/59. Class 80 (2). [Also in Group XXXI] Gearing for a tractor comprises an input shaft 10 driving through a two-speed constant-mesh countershaft gear having selectively engageable hydraulically controlled multi-disc ratio establishing clutches 24, 26 to a shaft 22 carrying gears 76, 78 selectively meshed by a double gear 72 sliding upon a shaft 70 to give a further two speeds, a gear 80 splined upon the shaft 70 meshing a gear 82 splined upon a parallel shaft 28. The end 12 of the shaft 70 can be used as a power take-off shaft: Forward and reverse gears 86, 84 are selectively coupled to the shaft 70 by ratio establishing hydraulically controlled multi-disc clutches 90, 88, and forward and reverse gears 92, 94 are similarly coupled to the shaft 28 by selectively engaged ratio establishing hydraulically controlled multi-disc clutches 96, 98, the two gears 84, 92 both meshing a gear 100 (shown out of plan in Fig. 3) on a shaft 30 and the two gears 86, 94 meshing a corresponding gear 102 on a parallel shaft 30. Bevel gearing 38 connects the two shafts 30 to coaxial output shafts 32 driving through reduction gearing and through chains and sprockets (not shown) to the tracks or road wheels of the tractor. Brakes 40 can be applied to station the two shafts 30. The arrangement is such that either both road wheels can be driven forwards or backwards at the same time; or one can be driven forwards or backwards while the other is stationary, or one can be driven forwards while the other is driven backwards. Each of the ratio establishing clutches is similar to the clutch 26, which comprises a drum 50, Fig. 4, secured to the shaft 22 and connected by multi-discs 54 to the hub 52 of the gear 46, springs 58 biasing a ring- shaped piston 56 to the disengaged position, but the admission of fluid under pressure through ducts 62, 64 and through shaft ducts (not shown) to a cylinder 66 moving the ring- shaped piston against the bias of its springs to engage the clutch.