PURPOSE: To improve wear resistance by providing a recess portion at a clutch gear and at the same time, making the axial sizes of cone surfaces large by providing a projecting portion at a synchronous link.

CONSTITUTION: A toothed wheel 14 is supported rotatably through a bearing 12 against a rotary shaft 10, and at the toothed wheel 14, a clutch gear 16 which is united with this wheel 14 in spline and rotates integrally, is provided. A synchro hub 18 united in spline so as to rotate integrally with a shaft 10, has a spline 18a at its outside diameter portion, and a coupling sleeve 20 is united with this in such a way as to be able to move axially. A synchronous link 22 is provided between the gear 16 and the synchro hub 18, and a projecting portion 22a is provided at the synchronous link 22, and the axial sizes of cone surfaces 26a and 24a are large enough for this much. Accordingly, axial sizes under which cone surfaces 26a and 24a come into contact in friction with the cone surfaces 28a and 28b of a cone ring 28, become large, and the volume of a cone clutch constituted with these cone surfaces increases. Therefore, surface pressure which acts upon cone surfaces 26a, 24a and 28a, 28b, lowers, and the quality of anti-wear is improved.