Proper mounting requires professionalism, care, cleanliness, precision, and the correct tools. Bearings are very important machine components that require high accuracy to do their job properly. It is essential that qualified and well-equipped workers perform the mounting.

As a general rule, mounting and dismounting forces should not be transferred over roller units and raceways. Bearings will only function properly if mounted correctly.


Mounting on shaft

Bearings with cylindrical bores are usually mounted by pressing them on the shafts (press fit) or heating them to expand their diameter (shrink fit). The seating surface on the shaft should be lightly oiled before mounting. The bearing can be driven into position by applying light hammer blows through a rubber-made inserted piece. If heating is used, temperatures should not be higher than 125°C and necessary temperature differences can be determined using the bearing and shaft (housing) measurements in diagram X.


Necessary temperatures for bearing mounting


Mounting bearings with tapered bore

Bearings with tapered bores can be mounted directly onto tapered shafts or cylindrical shafts using tapered sleeves and an axial locking device (shaft nut, end cover). Fitting does not depend on the size of the bore and shaft but on the length that the bearing is pulled onto the tapered seating. Bearing clearance is reduced that way.


Mounting in housing

Bearing housings are assemblies designed to make it easy to install bearings and shafts, while protecting bearings, extending their operating life and simplifying maintenance. These units are designed for self-aligning ball bearings, spherical roller bearings and CARB toroidal roller bearings.
Housed bearings provide shaft support for radial, thrust or a combination of loads. Mounted bearing types include pillow blocks (solid or split), flanged cartridges, cylindrical cartridges and take-up units.


Recommended fits

The tolerances of the bore and outside diameter of rolling bearings are internationally standardised. The following factors should be considered: conditions of rotation, the magnitude of the load, bearing internal clearance, temperature conditions, running accuracy requirements, design and materials of seatings, ease of mounting and dismounting, and displacement of the non-locating bearing.


Tolerances classifications



If you plan to reuse bearings after removal, the dismounting forces should not impact roller units and the raceway of the bearing. Smaller bearings can be dismounted with light hammer strokes through a rubber-made inserted piece on the ring face. It is better to work using tools for the dismounting process, screws, induction heaters or slotted rings. Bearings with a tapered bore can be removed by loosening the sleeve nut and then using a hammer and tubular insert. Larger bearings with a tapered bore should be dismounted using hydraulics.


If you’re uncertain about the proper installation process, it’s always best to consult the manufacturer’s guidelines or seek assistance from a professional to ensure accurate bearing mounting. In case you need any assistance, Codex Team is ready to help you with expertise. 

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