Patent ID: 7871201

Claim:
A tapered roller bearing comprising: an outer ring; an inner ring including a large rib portion; a plurality of tapered rollers interposed between the outer and inner rings; and a cage for the tapered rollers, wherein LWR/DW is within a range of 1.1 to 1.7 where LWR represents a roller effective length of the tapered rollers and DW represents a roller mean diameter of the tapered rollers, wherein RCO/LRO is 30 to 150, and RCI/LRI is 50 to 260 where RCO represents a crowning radius of the outer ring, LRO represents a raceway length of the outer ring, RCI represents a crowning radius of the inner ring and LRI represents a raceway length of the inner ring, and wherein the following expressions are satisfied: 20°≦α≦30°, and α−0.87γ−0.334 ≦BK≦α− 0.87γ−0.167, where α represents a raceway angle of the outer ring, γ represents a roller angle of the tapered rollers, and BK represents a rib angle of the large rib portion of an inner ring.