Shaft-mounted gearboxes as well as motor are mounted straight around the equipment shaft. The blended bodyweight of the gearbox and motor overhangs within the equipment shaft would make this mounting system appropriate for very simple and light-weight gearboxes. It divides the Doggy clutch into a synchronizer hub and change sleeve(pinion). https://gearbox89990.ltfblog.com/32629128/detailed-notes-on-gearbox