Assembly for constituting a stepless speed change gear of friction-drive type

Claim 1

An assembly for a stepless speed change gear of the friction-drive type comprising: a shaft; a small diameter disc on the shaft; a large diameter disc arranged coaxially on the shaft; an axially movable ring member; one of the ring member and the large diameter disc being constrained against rotation so that rotation of the other is transmitted as output rotation; speed-changing means for axially moving the ring member; an annular carrier disposed around the shaft and positioned between the small diameter disc and the large diameter disc; a plurality of conical rollers, each of which is mounted on the annular carrier and each of which has: a conical surface frictionally and internally engaging the ring member, a first annular power transmitting surface frictionally engaging the small diameter disc, and a second power transmitting surface frictionally engaging the large diameter disc; a contact pressure generating means of the cam-type for generating contact pressures at three frictional engagement points on each conical roller comprising: the shaft, a collar provided on the shaft, and a snap ring engaging the shaft; the small diameter disc, the large diameter disc and the contact pressure generating means being supported between the collar and the snp-ring by the single shaft so as to prohibit axial runout between the small diameter disc, the large diameter disc and the contact pressure generating means along the shaft; and the small diameter disc, the large diameter disc, the contact pressure generating means and the shaft being radially constrained by the ring member.