Rolling bearing

A rolling bearing, comprising:

• an outer ring and an inner ring disposed rotatable relative to each other;
• a plurality of rolling elements incorporated rollably between the outer ring and the inner ring;
• a housing into which the outer ring fits by insertion of the roller bearing into the housing in an axial direction of the roller bearing;
• a shaft on which the inner ring fits;
• a recessed groove formed in one or both of an outer circumferential surface of the outer ring and an inner circumferential surface of the inner ring so as to extend continuously in a circumferential direction thereof;
• and
• an O-ring made of an elastic member and accommodated in the recessed groove,
• wherein the rolling bearing supports rotation between the shaft and housing,
• the recessed groove includes a first bottom surface having a given depth and a second bottom surface having a larger depth than the first bottom surface,
• the O-ring comprises a projecting portion having a rounded surface in the axial direction of the roller bearing and projected from the recessed groove, and a stepped surface provided on a side opposite to the projecting portion, the stepped surface comprising a first surface fitted with the first bottom surface of the recessed groove, and a second surface disposed between the first bottom surface and the second bottom surface of the recessed groove with respect to a radial direction of the rolling bearing,
• wherein,
• when the projecting portion of the O-ring is not pressed, the second surface is disposed between the first bottom surface and the second bottom surface of the recessed groove with respect to the radial direction of the rolling bearing such that a clearance is formed between the second surface of the O-ring and the second bottom surface, and a dimension of the clearance is smaller than a projection amount of the projecting portion, and
• when the projecting portion is pressed, the O-ring elastically deforms such that the second surface of the O-ring contacts the second bottom surface.