Patent ID: 7677809

Claim:
A tapered roller bearing comprising: an outer ring; an inner ring; a plurality of tapered rollers interposed between these rings; and a retainer for retaining the tapered rollers, wherein a roller loading ratio represented by z·DW/(π·dm) is in a range of 0.7 to 0.92, and a ratio of roller length to roller diameter as represented by LWR/DW is in a range of 1.1 to 1.7, provided that z denotes a number of rollers, LWR denotes an effective length of the roller, DW denotes a mean diameter of the roller and dm denotes the Pitch Circle Diameter (PCD) of a roller, and wherein an outer-ring crowning parameter (=RCO/LRO) is in a range of 30 to 150, and an inner-ring crowning parameter (=RCI/LRI) is in a range of 50 to 260, provided that RCO denotes a radius of an outer-ring crowning, LRO denotes a raceway length of the outer ring, RCI denotes a radius of an inner-ring crowning, and LRI denotes a raceway length of the inner ring.