Abstract: An environment-friendly rolling bearing is proposed in which at least one of inner ring, outer ring, rolling elements, seals and retainer is formed of a biodegradable material.

Abstract: A machine part is proposed which is made from TPI resin and is high in wear resistance and durability. The machine part is formed from a composition comprising 100 parts by weight of a thermoplastic polyimide resin, and 10-100 parts by weight of a reinforcing material, the thermoplastic polyimide resin having a crystallinity of 10% or over. The machine part may be a gear, a friction wheel or a cam used in a mechanical transmission. The crystallinity of the resin is adjusted to 10% or over by injection-molding the resin composition, and heating the thus injection-molded article at 220-340° C. for 5-24 hours.

Abstract: A biodegradable lubricative resin composition which withstands use as a material for sliding parts, and slide bearings and gears made from such a resin composition. The resin composition contains an aliphatic polyester which is a monopolymer or copolymer of a hydroxy-carboxylic acid or an aliphatic polyhydroxy alcohol and an aliphatic polybase, the aliphatic polyester preferably containing 50-100 wt % lactic acid, and a lubricant which is a lubricating oil or a solid lubricant. Slide bearings and gears molded from such a resin composition are also proposed.