Compound vehicular transmission

A compound vehicular transmission for providing a plurality of selectable speed ratios between an input shaft and an output shaft, the transmission comprising:

• an intermediate shaft disposed between the input and output shafts;
• a main countershaft;
• a first splitter gear coaxial with and selectively engageable to the input shaft;
• a second splitter gear coaxial with the input shaft and the intermediate shaft and selectively engageable to at least one of the input shaft and the intermediate shaft;
• a plurality of intermediate shaft drive gears selectively coupleable to the intermediate shaft;
• a plurality of main countershaft gears fixed for rotation with the main countershaft, each of the main countershaft gears being in continuous meshing engagement with a corresponding one of the first and second splitter gears and the plurality of intermediate shaft drive gears;
• an intermediate shaft output gear fixed for rotation with the intermediate shaft;
• an output shaft range gear selectively engageable to the output shaft for selective rotation therewith;
• a two-way synchronizer coupling means fixed for rotation with the output shaft and operable for coupling only one of the intermediate shaft output gear and the output shaft range gear to the output shaft;
• an auxiliary countershaft assembly comprising an auxiliary countershaft, a first auxiliary countershaft gear fixed to the auxiliary countershaft and in continuous meshing engagement with the output shaft range gear, and a second auxiliary countershaft gear surrounding said auxiliary countershaft and in continuous meshing engagement with the intermediate shaft output gear;
• and
• a clutch assembly fixed for rotation on the auxiliary countershaft and having a first position for coupling said auxiliary countershaft to said main countershaft and a second position for coupling the second auxiliary countershaft gear to the auxiliary countershaft.

A compound vehicular transmission for providing a plurality of selectable speed ratios between an input shaft and an output shaft, the transmission comprising:

• an intermediate shaft disposed between the input and output shafts;
• a main countershaft;
• a first splitter gear coaxial with the input shaft and selectively engageable thereto;
• a second splitter gear coaxial with the input shaft, selectively engageable with at least one of the input shaft and the intermediate shaft;
• a two-speed friction clutch splitter having a first position for coupling the input shaft to the first splitter gear, a second position for coupling the input shaft to the second splitter gear, and a third position for decoupling the first and second splitter gears from the input shaft;
• a plurality of intermediate shaft drive gears selectively engageable to the intermediate shaft for rotation therewith;
• a plurality of main countershaft gears fixed for rotation with the main countershaft, each of the plurality of main countershaft gears being in continuous meshing engagement with a corresponding one of the first and second splitter gears and the plurality of intermediate shaft drive gears;
• an intermediate shaft output gear fixed for rotation with the intermediate shaft;
• an output shaft range gear coaxial with and selectively engageable to the output shaft;
• a two-way synchronizer coupling means fixed for rotation with the output shaft and operable for coupling one of the intermediate shaft output gear and the output shaft range gear to the output shaft;
• an auxiliary countershaft assembly comprising an auxiliary countershaft, a first auxiliary countershaft gear fixed to the auxiliary countershaft and in continuous meshing engagement with the output shaft range gear, and a second auxiliary countershaft gear coaxial with said auxiliary countershaft and in continuous meshing engagement with the intermediate shaft output gear;
• and
• a clutch assembly fixed for rotation with the auxiliary countershaft and having a first position for coupling said auxiliary countershaft to said main countershaft.