A variator having at least one roller which runs upon at least one race to transfer drive from one to the other at variable ratio. The variator has a fluid supply for supplying fluid to the race and roller thereby to provide a fluid film by which the roller and the race are separated in use. The roller has a running surface with root means square roughness R.sub.q(roller) and the race having a root means square roughness R.sub.q(race). The variator's specific film thickness is the minimum thickness of the fluid film in normal operation divided by the composite roughness, and is less than 1.0. At least one of the roller and the race has a powder metal surface with a Ra roughness above 0.1 micrometers.

A high durability roller, a manufacturing method thereof and a power transmission device with the high durability roller are provided. The roller for a power transmission device that comprises a plurality of rollers in contact with each other directly or with lubricant between them, includes: a metal base having a Young's modulus of 220 GPa or less; and a coating that is formed on a surface of the metal base, includes hard particles and a metal component composed of at least either simple metal or alloy, and has a Young's modulus of 250 GPa or more. The power transmission device includes the roller. The method of manufacturing the roller includes: forming the coating on the surface of the metal base by thermal spraying using a thermal spray material that comprises the hard particles and the metal component composed of at least either simple metal or alloy.

A high durability roller, a manufacturing method thereof and a power transmission device with the high durability roller are provided. The roller for a power transmission device that comprises a plurality of rollers in contact with each other directly or with lubricant between them, includes: a metal base having a Young's modulus of 220 GPa or less; and a coating that is formed on a surface of the metal base, includes hard particles and a metal component composed of at least either simple metal or alloy, and has a Young's modulus of 250 GPa or more. The power transmission device includes the roller. The method of manufacturing the roller includes: forming the coating on the surface of the metal base by thermal spraying using a thermal spray material that comprises the hard particles and the metal component composed of at least either simple metal or alloy.

A pulley assembly having a body, a shaft mount and a plurality of bolts is disclosed. The body is aligned to the shaft mount by providing a tight tolerance between a shoulder portion of the bolt and a neck portion of a counter sunk hole formed in the body. Additionally, an outer surface of the body may have a pattern of friction lines or patches formed by fusing particulate matter to the outer surface with heat generated by a laser beam.

A power transmission roller assembly includes a power transmission roller configured to be brought into contact with the driving roller and the driven roller, a pivot shaft fixed to a vehicle body, a pivot arm arranged radially inside of the power transmission roller and pivotally mounted on the pivot shaft, and a roller support bearing rotatably supporting the power transmission roller. A pair of biasing members are mounted to the pivot arm and bias the roller support bearing to a predetermined position between the driving roller and the driven roller such that the abutment force between the driving roller and the power transmission roller is balanced with the abutment force between the driven roller and the power transmission roller. Sliding members are mounted on respective shafts of the biasing members to extend through the sliding members, and frictional forces are generated between the sliding members and the respective shafts.

A power transmission roller assembly includes a power transmission roller configured to be brought into contact with the driving roller and the driven roller, a pivot shaft fixed to a vehicle body, a pivot arm arranged radially inside of the power transmission roller and pivotally mounted on the pivot shaft, and a roller support bearing rotatably supporting the power transmission roller. A pair of biasing members are mounted to the pivot arm and bias the roller support bearing to a predetermined position between the driving roller and the driven roller such that the abutment force between the driving roller and the power transmission roller is balanced with the abutment force between the driven roller and the power transmission roller. Sliding members are mounted on respective shafts of the biasing members to extend through the sliding members, and frictional forces are generated between the sliding members and the respective shafts.

An eccentric assembly for a walking mechanism is provided. The eccentric assembly includes a barrel member and a shaft member. The barrel member includes a circumferential portion extending in a longitudinal direction and a web portion extending inwardly from the circumferential portion. Further, the web portion includes a cut-out region and an inner periphery outlining the cut-out region. The shaft member includes a tubular portion extending in the longitudinal direction and a flange portion extending outwardly from the tubular portion. The flange portion includes an outer periphery. Further, the shaft member is coupled to the barrel member such that the outer periphery of the flange portion substantially conforms to the inner periphery of the web portion. Further, the flange portion is configured to adjust an eccentricity of the shaft member with respect to the barrel member.

The invention relates to the control mechanism developed for continuously variable transmission systems which are chain/belt-driven and which are used in the vehicles with electrical, hybrid and conventional internal combustion engine as an automatic gearbox system in the automotive industry.

A slide member is provided with a base material, a plated slide layer and an intermediate plated layer. The plated slide layer contains a solid lubricant. The intermediate plated layer is disposed between the base material and the plated slide layer, the intermediate plated layer increasing cohesion of the base material and the plated slide layer. The plated slide layer has a content of the solid lubricant in a range from 30 to 70 vol %, inclusive.

A slide member is provided with a base material, a plated slide layer and an intermediate plated layer. The plated slide layer contains a solid lubricant. The intermediate plated layer is disposed between the base material and the plated slide layer, the intermediate plated layer increasing cohesion of the base material and the plated slide layer. The plated slide layer has a content of the solid lubricant in a range from 30 to 70 vol %, inclusive.