THRUST NEEDLE ROLLER BEARING, SUPPORT STRUCTURE RECEIVING THRUST LOAD OF COMPRESSOR FOR CAR AIR-CONDITIONER, SUPPORT STRUCTURE RECEIVING THRUST LOAD OF AUTOMATIC TRANSMISSION, SUPPORT STRUCTURE FOR NONSTEP VARIABLE SPEED GEAR, AND SUPPORT STRUCTURE RECEIVING THRUST LOAD OF MANUAL TRANSMISSION

摘要

A thrust needle roller bearing (10A, 10B) has a washer (1) formed of a thin steel plate and needle rollers (2), at least said washer (1) has a nitrogen enriched layer at a surface layer portion, amount of retained austenite in said surface layer portion is at least 5 volume % and at most 25 volume %, and austenite grain number of said surface layer portion is 11 or higher. Thus, a long life thrust needle roller bearing resistant to an early failure caused by surface damage such as surface-originated flaking and also resistant to common, load dependent rolling contact fatigue can be provided.