Patent ID: 7048445

Claim:
A cylindrical roller bearing comprising: an inner ring having a raceway on an outer circumference thereof; an outer ring having a raceway on an inner circumference thereof; a plurality of cylindrical rollers disposed to roll freely between the raceway of the inner ring and the raceway of the outer ring; flange portions being disposed on both sides respectively of the raceway of at least one of the inner ring and the outer ring; and a recess groove disposed at a corner portion where a flange surface of at least one of the flange portions of both sides and the raceway meet, the flange surfaces being inclined at the same angle from a base end portion to a tip end portion thereof, wherein a radial dimension h 3 of chamfers formed on outer circumferential edge portions of the cylindrical rollers is set smaller than a radial height h 1 from the raceway near the recess groove, curved portions being formed between the chamfers and end surfaces of the cylindrical rollers, and the curved portions are regulated to be a shape wherein the following expressions are satisfied: 0.8≦ h 2 /h 1 1≦tan −1 [δ/( h 2 −h 3 )](°) where h 1 is a radial height from the raceway near the recess groove, h 2 is a radial dimension from the roller surfaces of the cylindrical rollers to a boundary between the curved portions and the end surfaces, h 3 is a radial dimension of the chamfers of the cylindrical rollers, and δ is an axial dimension from a boundary between the chamfers and the curved portions to the end surfaces of the cylindrical rollers.