Abstract: Each steel element for a V-belt of a continuously variable transmission has a flank (4a) that comprises a plurality of equally spaced raised portions (41) each being placed between two fine grooves (42). A flat flatness ratio (FR) given by the equation (1) is set to the highest one of values that are capable of practically machining the flank (4a) of the steel element (4) and capable of causing the flank (4a) to exhibit a given and satisfied lubrication oil discharging effect, and a groove pitch (GP) that is a distance between the two fine grooves (42) is set to a value that is capable of practically machining the flank of the steel element and capable of causing the flank to exhibit a given and satisfied lubrication oil discharging effect. The groove pitch thus set is a value that is permitted by the higher value of the flatness ratio thus set. FR (%)=WRP/(WRP+WG)×100??(1) wherein: FR: Flatness ratio WRP: Width of the raised portion (41) WG: Width of the groove (42).

Abstract: Each steel element for a V-belt of a continuously variable transmission has a flank (4a) that comprises a plurality of equally spaced raised portions (41) each being placed between two fine grooves (42). A flat flatness ratio (FR) given by the equation (1) is set to the highest one of values that are capable of practically machining the flank (4a) of the steel element (4) and capable of causing the flank (4a) to exhibit a given and satisfied lubrication oil discharging effect, and a groove pitch (GP) that is a distance between the two fine grooves (42) is set to a value that is capable of practically machining the flank of the steel element and capable of causing the flank to exhibit a given and satisfied lubrication oil discharging effect. The groove pitch thus set is a value that is permitted by the higher value of the flatness ratio thus set.

Abstract: A vane wheel for torque converter with a plurality of blades formed integrally with a shell in a casting process is disclosed. The blade tilts relative to an axial direction of the vane wheel and has an inner surface located on a positive pressure side thereof and an outer surface located on a negative pressure side thereof. A root thickness in a middle section between an outer periphery side and an inner periphery side of the shell is thicker than a root thickness on the inner periphery side relative to a blade cross section along a circumferential direction from an axis center of the vane wheel.

Abstract: A vane wheel for torque converter with a plurality of blades formed integrally with a shell in a casting process is disclosed. The blade tilts relative to an axial direction of the vane wheel and has an inner surface located on a positive pressure side thereof and an outer surface located on a negative pressure side thereof. A root thickness in a middle section between an outer periphery side and an inner periphery side of the shell is thicker than a root thickness on the inner periphery side relative to a blade cross section along a circumferential direction from an axis center of the vane wheel.