Synchronising unit for vehicle gearbox - has friction ring pressed toward sleeve gear during gear change to increase servo effect

摘要

Synchronisation is increased independently of the forces engaged in the gear change. A toothed sleeve is retained on a carrier fitted on the gear drive shaft. The sleeve is engageable with the appropriate gearwheel and opposed to the synchronisation effect produced by friction components. A synchronisation ring (11, 12) is incorporated. Through the heightening of the servo effect of the ring (11, 12) by stop bodies during the synchronisation process, a friction ring (20) is activated and pressed counterposed to the muff (6) change direction, being brought into friction engagement with the change muff carrier (8).