Method of assembling tapered roller bearing, and jig for use in the method

A method of assembling a tapered roller bearing that includes an inner ring, an outer ring, a plurality of tapered rollers interposed between the inner ring and the outer ring, and an annular cage in which pockets that hold the tapered rollers are formed in a circumferential direction, the method comprising:

• the steps of
• (a) constituting a cage assembly in which the tapered rollers are temporarily housed in the pockets so as not to slip off radially outward;
• (b) constituting an inner ring assembly by moving the cage assembly in an axial direction to approach the inner ring from a side near a cone front face rib portion of the inner ring, and causing the tapered rollers of the cage assembly to climb over the cone front face rib portion to be fitted on an inner raceway surface of the inner ring;
• and
• (c) assembling the inner ring assembly and the outer ring to each other to obtain the tapered roller bearing, wherein:
• a jig is provided adjacent to the cone front face rib portion in step (b), the jig having an outer peripheral shape that is continuous with an outer peripheral surface of the cone front face rib portion, and including recessed grooves that are formed in an outer peripheral portion of the jig and that enable contact of the respective tapered rollers, the recessed grooves each having an inclined shape in which a groove bottom extends radially outward as the recessed groove extends toward one side in the axial direction, which is a cone front face rib portion side, and having a recessed arcuate shape in cross section;
• and
• in step (b), further, the cage assembly is relatively moved toward one side in the axial direction between the inner ring and the jig to increase a diameter of the cage by sliding the tapered rollers of the cage assembly radially outward along the recessed grooves so that the tapered rollers climb over the cone front face rib portion to be fitted on the inner raceway surface.