Abstract: A rolling bearing for a high-speed rotating equipment is constructed of an outer ring, an inner ring, rolling elements and a retainer to rotatably support at least a rotary shaft thereon. The retainer is composed of a molded porous synthetic resin body having a porous portion of a communicated structure in at least a part thereof. Further, the is lubricated with a lubricating oil comprising a nondrying vegetable oil.

Abstract: A process is provided for the production of a porous retainer for use in a rolling bearing for holding rolling elements. The process comprises the following steps:(1) blending a polyimide resin, which serves as a porous matrix material for the porous retainer, with another heat-resistant resin which has a forming temperature range close to the polyimide resin and, when treated with a solvent in the presence of the polyimide resin, is solely dissolved out;(2) forming the resulting resin blend into a retainer of a desired shape; and(3) treating the thus-formed retainer with the solvent, whereby the another heat-resistant resin is solely dissolved out.

Abstract: An odontotherapeutic hand piece is formed of a head portion, a handle portion connected to the head portion and a coupling portion arranged in continuation with the handle portion. A rotary member provided with turbine blades is accommodated in the head portion. The odontotherapeutic hand piece has a working medium conduit, which is arranged in an internal space of the coupling portion and is detachably engaged with the coupling portion for supplying a working medium to the odontotherapeutic hand piece. The head portion, the handle portion and the coupling portion are made of a material which permits integral molding. The head portion, the handle portion and the coupling portion are integrally joined together.