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.

An illustrative example embodiment of an elevator sheave liner includes a liner body having an inner surface configured to be received against a sheave and an outer surface configured to engage an elevator tension member. The liner body comprises a polymer material and a plurality of wear resistance particles in the composite material. The wear resistance particles are nanoparticles or microparticles. At least some of the wear resistance particles establish a traction characteristic of the outer surface of the sheave liner.

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.

An illustrative example embodiment of an elevator sheave liner includes a liner body having an inner surface configured to be received against a sheave and an outer surface configured to engage an elevator tension member. The liner body comprises a polymer material and a plurality of wear resistance particles in the composite material. The wear resistance particles are nanoparticles or microparticles. At least some of the wear resistance particles establish a traction characteristic of the outer surface of the sheave liner.

A rack bar includes: a rack tooth row including a plurality of rack teeth meshing with pinion teeth; a hardened layer provided continuously over an entire circumference of the rack tooth row; and a center portion provided inside the hardened layer and having lower hardness than the hardened layer. When the rack bar is viewed in an axial direction of the rack bar, a depth of the hardened layer from the following positions i), ii), and iii) increases in this order: i) a bottom land of the rack teeth; ii) a side of the rack bar relative to the bottom land; and iii) a back of the rack bar relative to the bottom land.

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 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 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 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.