Gear change box with multiple steps

摘要

PCT No. PCT/EP90/01056 Sec. 371 Date Jan. 3, 1992 Sec. 102(e) Date Jan. 3, 1992 PCT Filed Jul. 2, 1990 PCT Pub. No. WO91/00445 PCT Pub. Date Jan. 10, 1991.The gear-change transmission has a closely stepped input group (7) before a main group for fine tuning the speed within a working range. Between the input group (7) and the main group (8) is situated a pressurized-oil cooled drag-torque reducing multi-disc starting clutch (26) so that the gears in both groups can also be easily engaged when using synchronizer positive clutches (18, 20). A reversing shaft (13) for reverse gear is fully integrated in the input group (7) and its gear clutches (F/G) can be introduced with a gear selector (83, 112) the same as for the remaining splitter gears of the input group (7). A change-over clutch (36) for an intermediate transmission (9) is optionally placed directly before the starting clutch (26) operatively and structurally on the primary shaft (32) of the starting clutch (26). The main drive shaft (10) is guided parallel to the countershaft (12) and to the drive shaft (39) of the main group (8) through the common transmission housing (1) and is connectable, via a separating clutch (67) and via a two-step transmission group (68, 69, 70, 71, 72), with a power take off shaft (73). The input group (7), with the same arrangement of the shafts (11, 12, 13), can be equipped either with hydraulic double gear clutches (A, B, C, D, F, G) axially aligned in respect to each other or with double synchronizer clutches. In the first case, there is provided over the main group (8) on the main drive shaft (10), a change-over clutch (25) for a mechanical bypass operative connection of the powershift clutches (14, 15, 16) utilizable in forward or reverse direction for towing or emergency possibilities.