Parallel shaft transmission

A parallel shaft transmission comprising:

• an input shaft, a first counter shaft, a second counter shaft and an output shaft which are extended in parallel, said first counter shaft being arranged coaxially with said output shaft so as to be rotatable relatively thereto;
• two sets of first change gear trains comprising first and second change drive gears established rotatably on said input shaft, and first and second change driven gears established rotatably on said first counter shaft and engaging with said first and second change drive gears respectively;
• first and second clutch means established on said input shaft for connecting and disconnecting said input shaft to and from said first and second change drive gears;
• two sets of second change gear trains comprising third and fourth change drive gears established rotatably on said first counter shaft, and third and fourth change driven gears established rotatably on said second counter shaft and engaging with said third and fourth change drive gears respectively;
• third and fourth clutch means established on said second counter shaft for connecting and disconnecting said second counter shaft to and from said third and fourth change driven gears;
• a third change gear train comprising fifth change drive gear established jointly on said second counter shaft and a fifth change driven gear established jointly on said output shaft and engaging with the fifth change drive gear;
• and
• fifth clutch means established between said first counter shaft and said output shaft for connecting and disconnecting said first counter shaft to and from said output shaft.