Nissan Motor Company Limited

Jatco Corporation

Shinji Kiyohara

Atsuhiro Mori

Yoshitaka Miura

Kouhei Toyohara

Kazuhiro Mizumiya

Takeshi Kariya

Tsutomu Kamitani

Each steel element for a V-belt of a continuously variable transmission has a flank () that comprises a plurality of equally spaced raised portions () each being placed between two fine grooves (). 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 () of the steel element () and capable of causing the flank () to exhibit a given and satisfied lubrication oil discharging effect, and a groove pitch (GP) that is a distance between the two fine grooves () 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)&#xd7;100&#x2003;&#x2003;(1)

Metal V-belt of continuously variable transmission

Under control of rotation of a crankshaft, a friction rolleris pressed against a friction rollerin a radial direction, so as to achieve torque transmission between the rollers. An inter-roller radial pressing reaction is canceled as an internal force in bearing supports, with no input to a housing. The reaction causes a radial displacement of a bearing-fitting portion provided with inner and outer bearingsin double layer arrangement, wherein the radial displacement is larger than that of a bearing-fitting portion provided with a bearingin single arrangement, so as to cause unbalanced contact between rollers. In order to prevent this, support stiffness of bearing supportagainst the inter-friction-roller radial pressing reaction is set higher than that of bearing support

Friction-roller type transmission mechanism

Growing community of inventors

Ebina, Japan

Shinji Kiyohara