Combined conical roller bearing unit and method for manufacturing same
A roller bearing unit includes a shaft having a stepped part along a longitudinal axis; a first conical roller bearing which abuts the stepped part; a spacer that abuts, from a side opposite the stepped part, a first outer ring of the first conical roller bearing; a second conical roller bearing having a second outer ring that sandwiches the spacer between the first outer ring and the second outer ring, and a pressing member that is attached to the shaft and presses the first inner ring and the second inner ring in a direction to cause the first inner ring and the second inner ring to approach each other. A recess is recessed in a radial direction in an outer surface of the spacer to enable an external force along the longitudinal axis direction to be applied to the first outer ring from the spacer side.
1 . A combined conical roller bearing unit comprising:
a shaft having a stepped part at one portion in a direction along a longitudinal axis, the stepped part extending in a direction orthogonal to the longitudinal axis;
a first conical roller bearing having a first inner ring to which the shaft is fitted and which abuts the stepped part in the direction along the longitudinal axis;
a spacer having an abutting surface that abuts, from a side opposite the stepped part in the direction along the longitudinal axis, a first outer ring of the first conical roller bearing;
a second conical roller bearing having a second outer ring that sandwiches the spacer between the first outer ring and the second outer ring, and a second inner ring to which an outer surface of the shaft is fitted; and
a pressing member that is attached to the shaft and that presses the second inner ring in a direction to approach the first inner ring,
wherein the spacer includes at least one recess which is recessed in the direction orthogonal to the longitudinal axis in at least a portion of an outer surface of the spacer,
wherein the at least one recess is configured to receive an external force for applying a force in the direction along the longitudinal axis to the first outer ring from the spacer side,
wherein the stepped part is configured to receive an external force for applying a force in the direction along the longitudinal axis to the first inner ring from the stepped part side,
wherein the at least one recess comprises a plurality of recesses, and
wherein the plurality of recesses are spaced apart in a circumferential direction about the longitudinal axis.
2 . The combined conical roller bearing unit according to claim 1 , wherein the plurality of recesses are notches formed by cutting out the abutting surface.
3 . The combined conical roller bearing unit according to claim 1 , wherein an outer diameter of the first outer ring is larger than an outer diameter of the second outer ring.
4 . The combined conical roller bearing unit according to claim 3 , wherein the spacer includes an outer circumferential surface that has an outer diameter equal to the outer diameter of the first outer ring, an inner circumferential surface that has an inner diameter equal to the outer diameter of the second outer ring, and a stepped part against which an end face of the second outer ring on the first outer ring side is abutted.
5 . 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.
6 . The method for manufacturing a combined conical roller bearing unit according to claim 5 , 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.
7 . 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.