| 摘要 |
PURPOSE:To achieve higher durability by forming at least one part among bearing components in a handpiece from a ceramic containing zirconium oxide while a misting means is interposed in an air supply path to obtain sufficient lubrication performance without use of oil. CONSTITUTION:In a dental handpiece, a turbine blade integrated with a rotation shaft rotating having a cutting tool mounted thereon is rotated by a compressed fluid to be supplied via an air supply path. The turbine blade and the rotation shaft are housed into a housing comprising a head housing 4 and a cap housing 5 and the rotation shaft is supported with a bearing. In this case, at least one part among a rolling element and inner and outer races composing the bearing is formed from a ceramic containing zirconium oxide while a holder is made of polyamideimide. A lubricator 50 is interposed in the course of the air supply path to introduce a mixture of air and mist water to be jetted from an orifice 54 in the Venturi's principle. |
