| abstract |
A bearing contact member (11, 12, 21, 31, 32, 33, 13, 23, 34) in a roller bearing (1, 2, 3), the bearing contact member (11, 12, 21, 31, 32, 33, 13, 23, 34) one of a guide ring member (11, 12, 21, 31, 32, 33) and a bearing element (13, 23, 34) arranged in contact with said guide ring member (11, 12, 21, 31, 32, 33) on an annular bearing surface, the bearing contact member (11, 12, 21, 31, 32, 33, 13, being) 23, 34) configured as a sintered body containing ß-sialon as the main component and has a residue that is either formed by an impurity or formed by a sintering additive and an impurity, presenting the rolling contact member (11, 12, 21, 31, 32, 33, 13, 23, 34) a bearing contact surface (11A, 12A, 21A, 31A1, 31A2, 32A, 33A, 13A, 23A, 34A) that serves as a surface who contacts another bearing contact member (11 , 12, 21, 31, 32, 33, 13, 23, 34), said bearing contact surface (11A, 12A, 21A, 31A1, 31A2, 32A, 33A, 13A, 23A, 34A) included in a portion which has a high density layer (11B, 12B, 21B, 31B, 32B, 33B, 13B, 23B, 34B) of greater density than an internal portion (11C, 12C, 21C, 31C, 32C, 33C, 13C, 23C, 34C), wherein said high density layer (11B, 12B, 21B, 31B, 32B, 33B, 13B, 23B, 34B) has a surface included in a portion with a higher density layer (11D, 12D, 21D , 31D, 32D, 33D, 13D, 23D, 34D) of greater density than another portion of said high density layer (11B, 12B, 21B, 31B, 32B, 33B, 13B, 23B, 34B), characterized in that, when said higher density layer (11D, 12D, 21D, 31D, 32D, 33D, 13D, 23D, 34D) is observed in cross section with an optical microscope with oblique illumination, said layer shows a portion observed as a white portion of color that It has an area ratio equal to or less than 3.5% . |