GB1324765A - Change speed gear transmission systems - Google Patents

Abstract

1324765 Change-speed gear TATRA NARODNI PODNIK 19 April 1971 [5 March 1970] 24077/71 Heading F2D A series splitter and main change-speed gear combined in a single casing on a heavy motor vehicle having a backbone chassis and a multiaxle (two rear, one front) drive, is arranged to facilitate dismantling without the necessity for disturbing the chassis backbone. For this purpose the gear casing is split in a horizontal plane 3, the lower part 2 forming part of the backbone structure, and housing a final drive, whilst the upper part 1 houses the splitter 5, 6, 11, 12, and the main change-speed gear 10, 21, the upper whole being detachable as an assembly, after which the final drive in the lower casing part 2 can be dismantled as detailed below. Eight, ten or twelve forward ratios may be provided, and in Fig. 5, not shown, these may be doubled to twenty-four by an additional two-speed clutch on the final output shaft. The main gear provides a single reverse. In the twelve-ratio form shown, an enginedriven input shaft 4 drives a countershaft 10 at two speeds through a clutch 8 and splitter wheelpairs 6, 11; 5, 12. The countershaft 10 drives an intermediate shaft 21, arranged in the same horizontal plane (Fig. 2, not shown), at six ratios through clutches 14, 25 and 31, and one reverse through a clutch 35 and idler (61, Fig. 1, not shown) meshing wheels 18, 34. The intermediate shaft 21 drives a final output shaft assembly 36 through a single wheel 37, or pair of clutched wheels (Fig. 5, not shown). Final drive.-The output wheel 37 carries intermeshed planets of a torque-dividing differential, the pins 49, 51 of which are connected respectively through splined stub shafts 48, 60 to one rear axle drive shaft 70, and through an internally splined sleeve 58 to a second rear axle drive shaft, not shown. The output wheel 37 can also be clutched directly at 45, 46 to a front axle drive shaft 47. The differential drive between the two rear axles can be locked by a dog clutch 68. Dismantling is as follows. First the upper casing section 1, complete with shafts 4, 10, 21 and their wheels, is removed as an assembly, leaving the lower easing section 2, open at the top, still associated with the chassis backbone. Removal of bearing retaining rings 54, 57 then permits the differential assembly 37, complete with sleeve shaft 58, to be moved to the right, which causes one rear axle drive shaft 70 to thrust the inner stub shaft 48 leftwards relative to the differential assembly, overcoming a ball detent 50, so that the assembly is now free of the one axle shaft 70. The assembly is next movedleft to release external splines on the differential wheel 51 from the sleeve 58, after which the assembly is free of both rear axle shafts, and can be lifted out, either by splitting a divided bearing wall 55, or by tilting the assembly to pass through an undivided wall. Assembly reverses the above procedure, the inner shaft 48 being finally moved to its rightward position, shown, by inserting a tool through openings in the differential wall 39.