Coaxial Gearbox
We begin with a simple four-speed gearbox
The co-axial gearbox has the job of transferring the torque from the straight-mounted front engine to the rear axle, to convert it in all the gears bar one and to allow driving in reverse. In almost all cases it is mounted up
front behind the engine and the clutch. However, with transaxle drive it can be mounted directly in front of the rear axle. In the above figure you can see a four-
speed transmission from the 1970s.
All gears except the fourth through the lay shaft
The torque comes from the right of the engine and is transferred from the upper axle drive shaft through the pair of gearwheels on the far right, directly to the lay shaft (below).
The left shift-collar is shifted to the left. The smallest diagonally cut gearwheel on the lay shaft drives the largest diagonally cut gearwheel on the main shaft.
The left shift-collar is shifted to the right. The second smallest diagonally cut gearwheel on the lay shaft drives the second largest diagonally cut gearwheel on the main shaft.
The right shift-collar is shifted to the left. The third smallest diagonally cut gearwheel on the lay shaft drives the third largest diagonally cut gearwheel on the main shaft.
The right shift-collar is shifted to the right. The torque will not be transferred through the lay shaft, but directly through the main shaft without torque conversion.
The idler gear, in front in the above figure, is shifted to the right. The torque will be transferred through three straight-cut gearwheels from the lay shaft to the main shaft. 08/16
|