Patent ID: 6068564
Filing Date: 2000-05-30
Classification: F16H

Abstract:
A continuously variable transmission comprising:a primary pulley disposed on a power input shaft, said primary pulley including a fixed wheel counterpart which is fixed to said power input shaft and has a first sheave surface coaxial with said power input shaft, and a movable wheel counterpart which is movable in a direction of axis of said power input shaft and has a second sheave surface coaxial with said power input shaft, said second sheave surface facing said first sheave surface to form a first pulley groove, the width of the primary pulley being changeable with movement of said movable wheel counterpart;a secondary pulley disposed on a power output shaft, said secondary pulley includes a fixed wheel counterpart which is fixed to said power output shaft and has a third sheave surface coaxial with said power output shaft, and movable wheel counterpart which is movable in a direction of axis of said power output shaft and has a fourth sheave surface coaxial with said power output shaft, said fourth sheave surface facing said third sheave surface to form a second pulley groove, the width of the secondary pulley being changeable with movement to said movable pulley; andan endless belt wound on said primary pulley and said secondary pulley so that said secondary pulley is drivable connected to said primary pulley, an effective radius of said belt wound on each of said primary and secondary pulleys being changeable with a transmission ratio, said belt including a steel belt portion, and a plurality of steel elements supported on said steel belt portion and aligned along the steel belt portion, each steel element being engaged in said first pulley groove of said primary pulley and in said second pulley groove of said secondary pulley so as to be locatable between and contactable with the first and second sheave surfaces of the primary pulley and the third and fourth sheave surfaces of said secondary pulley, respectively;wherein the first and second sheave surfaces of said fixed and movable wheel counterparts of said primary pulley have a first surface roughness, and the third and fourth sheave surfaces of said fixed and movable wheel counterparts of said secondary pulley have a second surface roughness which is higher than said first surface roughness.