Patent ID: 6533091
Filing Date: 2003-03-18
Classification: F16D

Abstract:
A synchromesh unit for a transmission, comprising:a rotation shaft; a gear supported on said rotation shaft such as to be rotatable relative thereto, said gear having dog teeth in an outer periphery thereof; a hub locked to said rotation shaft; a sleeve axially slidably splined to said hub; a blocking ring disposed between said hub and said gear in such a manner as to be brought into friction engagement with said gear, said blocking ring having in an outer periphery thereof dog teeth adapted to mesh with spline teeth in an inner periphery of said sleeve; and a synchro-spring supported on an outer periphery of said blocking ring, wherein said blocking ring is pressed toward said gear with said synchro-spring by pressing said synchro-spring radially inwardly by projecting portions of said spline teeth in the inner periphery of said sleeve in conjunction with an axial movement of said sleeve, and in a state in which said blocking ring is in friction engagement with said gear, said spline teeth in the inner periphery of said sleeve are caused to mesh with dog teeth of said blocking ring and said dog teeth of said gear, whereby said gear is locked to said rotation shaft, said projection portions of said spline teeth of said sleeve each comprise a first inclined surface adapted to apply an axial load to said blocking ring via said synchro-spring in conjunction with the axial movement of said sleeve and a second inclined surface adapted to release said axial load, such that an axial distance between the gear side end of said first inclined surface and the gear side end of said second inclined surface is substantially equal to or slightly shorter than an axial distance between an end portion of said dog teeth of said gear and an apex of said synchro spring such that said synchro-spring is guided by said second inclined surface when said spline teeth in the inner periphery of said sleeve reach a position just before said spline teeth in the inner periphery of said sleeve mesh with said dog teeth of said gear after said spline teeth in the inner periphery of said sleeve mesh with said dog teeth of said blocking ring.