Patent ID: 8915648
Filing Date: 2014-12-23
Classification: B60G,F16C

Abstract:
1. A synthetic resin-made thrust sliding bearing including: a synthetic resin-made upper casing having an upper annular flat plate-shaped portion; a synthetic resin-made lower casing superimposed on said upper casing so as to be rotatable about an axis of said upper casing and having a lower annular flat plate-shaped portion which is opposed to said upper annular flat plate-shaped portion, a first and a second annular projection disposed on said lower annular flat plate-shaped portion concentrically therewith, and a lower annular recess surrounded by said first and said second annular projection; a synthetic resin-made thrust sliding bearing piece constituted by a disk which is disposed in the lower annular recess, and is brought into sliding contact with an upper surface of said lower annular flat plate-shaped portion defining a bottom surface of the lower annular recess and a lower surface of said upper annular flat plate-shaped portion, said disk having a circular hole in a central portion thereof; and a lubricating grease interposed at sliding interfaces between the lower surface of said upper annular flat plate-shaped portion and the upper surface of said lower annular flat plate-shaped portion defining the bottom surface of the lower annular recess and an upper surface and a lower surface of said thrust sliding bearing piece which are respectively brought into sliding contact with said lower surface and said upper surface, said upper casing being combined with said lower casing by causing an outer peripheral edge thereof to be resiliently fitted to an outer peripheral edge of said lower casing, said thrust sliding bearing piece being formed of a polyethylene resin whose density is 0.957 to 0.96 g/cm said lubricating grease including a methylphenyl silicone oil as a base oil and a thickener which is selected from 12(OH)StLi and silica to set a mixture consistency of the lubricating grease to not less than 335 and not more than 358, said methylphenyl silicone oil having a coefficient of kinetic viscosity at 25° C. which is not less than 45,000 cSt and not more than 200,000 cSt.