Cylindrical roller bearing

A cylindrical roller bearing comprising:

• an inner race;
• an outer race having ribs at both ends in an axial direction of said roller bearing and having a roller rolling surface between said ribs, said roller rolling surface including crowning portions and a linear-from portion interposed between said crowning portions;
• a plurality of cylindrical rollers disposed between said inner race and said outer race;
• and
• a cage disposed between said inner race and said outer race and provided with pocket portions in which said plurality of cylindrical rollers are respectively accommodated, said cage having a roller guide surface which is provided in a portion opposite to said linear-form portion at least except crowning portions in an axial direction of said roller rolling surface,
• wherein said cylindrical roller bearing satisfies a following relations
• 1.5×10−3D≦H≦9.0×10−3D
• and
• A/B=0.6-1.0
• where
• D is a diameter of an outer circumferential surface of an axial end portion of said cage,
• H is a size of an annular clearance between said outer circumferential surface of said cage and an outer race rib inner-diameter surface of said rib which is opposite to said outer circumferential surface of said cage,
• A is an axial length of said outer circumferential surface of said cage and
• B is an axial length of said outer race rib inner-diameter surface.

A cylindrical roller bearing comprising:

• an outer race;
• an inner race having ribs at both ends in an axial direction of said roller bearing and having a roller rolling surface between said ribs, said roller rolling surface including crowning portions and a liner-from portion interposed between said crowning portions;
• a plurality of cylindrical rollers disposed between said inner race and said outer race;
• and
• a cage disposed between said inner race and said outer race and provided with pocket portions in which said plurality of cylindrical rollers are respectively accommodated, said cage having a roller guide surface which is provided in a portion opposite to said linear-form portion at least except crowning portions in an axial direction of said roller rolling surface, wherein said cylindrical roller bearing satisfies a
• following relations
• 1.5×10−3D≦H≦9.0×10−3D
• and
• A/D=0.6-1.0
• where
• D is a diameter of an inner circumferential surface of an axial end portion of said cage,
• H is a size of an annular clearance between said inner circumferential surface of said cage and an inner race rib outer-diameter surface of said rib which is opposite to said inner circumferential surface of said cage,
• A is an axial length of said inner circumferential surface of said cage and
• B is an axial length of said inner race rib outer-diameter surface.