Abstract: A method for manufacturing a V-block of a metal belt type continuously variable transmission is provided. The V-block is formed by punching a V-block press material with a main punch and a counter punch. The V-block press material has a sectional view including an outer portion of about uniform width and a tapered inner portion with a slant gently inclined toward an innermost end of the material from a place distant from a rocking edge by a predetermined distance inward. The main punch and the counter punch have front shapes of the substantially same as that of the V-block, and either punch facing the rocking edge has a slant starting at a place corresponding to the rocking edge and extending inward rising gradually.

Abstract: A method for manufacturing a V-block of a metal belt type continuously variable transmission is provided. The V-block is formed by punching a V-block press material with a main punch and a counter punch. The V-block press material has a sectional view including an outer portion of about uniform width and a tapered inner portion with a slant gently inclined toward an innermost end of the material from a place distant from a rocking edge by a predetermined distance inward. The main punch and the counter punch have front shapes of the substantially same as that of the V-block, and either punch facing the rocking edge has a slant starting at a place corresponding to the rocking edge and extending inward rising gradually.

Abstract: A continuously variable transmission having a metal belt and pulleys is provided to effectively lubricate the pulley contact surfaces of a metal element of the belt of the transmission with lubricating oil supplied via a rotary shaft of the pulley. This makes it hard for a contaminant present in the lubricating oil to adhere to the metal element. When the saddle surface of the metal element is taken as a reference, the height h1 to the inner end in the radial direction of a pulley contact surface is set to be smaller than the height h2 to the inner end in the radial direction of the lateral middle part of an element main body. The inner end in the radial direction of the middle part of the element main body protrudes inwards in the radial direction by a distance d from the inner end in the radial direction of the opposite ends thereof.

Abstract: When a tangential friction force received by a pulley abutment surface 37 of a metal element 32 from a pulley is represented by FV; a radial distance from a point 45 of action of the tangential friction force to a rocking edge 40 located radially outside the friction force-acting point 45 is represented by L; a radially inward load received by the metal element 32 from a metal ring assembly 31 is represented by FL; and a thickness of the metal element 32 is represented by t, the radial distance L and the thickness t of the metal element are determined, so that a relation, L/t≦FL/2FV is established. Thus, even if a moment FV×L is applied to the metal element 32 by the tangential friction force FV, the moment FV×L can be canceled by a moment FL×(t/2) generated by a load FL for urging an edge a of a ring slot 35 by the metal ring assembly 31, thereby preventing the inclination of the metal element 32 to enhance the durability of the metal ring assembly.

Abstract: In a planetary differential gear system using helical gears, a clutch is interposed between a carrier for planetary gears and a differential casing, and adapted to be engaged by an axial thrust force produced by a sun gear. First and second axle shafts are provided with splined internal ends which are received in complementary bores of the sun gear and the carrier, respectively. The first axle shaft is received in a bore of the differential casing so as to be freely slidable and rotatable jointly with the sun gear. Therefore, the thrust force produced by the sun gear when a drive input is applied to the differential system can be transmitted to the friction clutch without being obstructed by the friction produced by the splined coupling between the first axle shaft and the sun gear, or disturbed by any unpredictable force of engagement between the first axle shaft and the sun gear.