Synchromesh gear-changing mechanism - has axial clearance between dog teeth unaffected by wear of synchromesh components

摘要

The synchromesh gear changing mechanism has one or more gears in constant mesh with the input power train, and an output shaft positively synchronised with the gear and coupled to it by a dog clutch. The synchromesh components (43,53) are so designed that as wear takes place they have no effect on the axial clearance between the two sets of dog teeth (41,51) during the synchronisation operation. The first axial engagement pressure, e.g. from a sliding sleeve (3), can be arranged to act directly on the synchromesh components (43,53), while a second and higher pressure initiates dog clutch engagement.