Combined conical roller bearing unit and method for manufacturing same

A method for manufacturing a combined conical roller bearing unit by using a robot, a hand with two claws being mounted on the robot, the method comprising:

• fitting a shaft having a stepped part at one portion in a direction along a longitudinal axis to a first inner ring of a first conical roller bearing, the stepped part extending in a direction orthogonal to the longitudinal axis, and inserting the shaft to a position at which the first inner ring abuts the stepped part in the direction along the longitudinal axis;
• abutting an abutting surface of a spacer, from a side opposite the stepped part in the direction along the longitudinal axis, on a first outer ring of the first conical roller bearing;
• bringing one of the two claws into contact with the stepped part and bringing the other of the two claws into contact with a recess, the recess being recessed in the direction orthogonal to the longitudinal axis in at least a portion of an outer surface of the spacer;
• in a state in which, by moving the two claws toward each other, a force in the direction along the longitudinal axis is applied to the first outer ring from the spacer side and a force in the direction along the longitudinal axis is applied to the first inner ring from the stepped part side, fitting the shaft to a second inner ring of a second conical roller bearing, and inserting the shaft to a position at which the spacer is sandwiched in the direction along the longitudinal axis between a second outer ring of the second conical roller bearing and the first outer ring;
• and
• pressing, by means of a pressing member attached to the shaft, the second inner ring in a direction to approach the first inner ring.

A method for manufacturing a combined conical roller bearing unit, the method comprising:

• fitting a shaft having a stepped part at one portion in a direction along a longitudinal axis to a first inner ring of a first conical roller bearing, the stepped part extending in a direction orthogonal to the longitudinal axis, and inserting the shaft to a position at which the first inner ring abuts the stepped part in the direction along the longitudinal axis;
• abutting an abutting surface of a spacer, from a side opposite the stepped part in the direction along the longitudinal axis, on a first outer ring of the first conical roller bearing;
• in a state of applying a force in the direction along the longitudinal axis to the first outer ring from the spacer side and applying a force in the direction along the longitudinal axis to the first inner ring from the stepped part side, fitting the shaft to a second inner ring of a second conical roller bearing, and inserting the shaft to a position at which the spacer is sandwiched in the direction along the longitudinal axis between a second outer ring of the second conical roller bearing and the first outer ring;
• and
• pressing, by means of a pressing member attached to the shaft, the second inner ring in a direction to approach the first inner ring,
• wherein the external force that has been applied to the first outer ring is released after a preload is applied to the first conical roller bearing by means of the pressing member.