The working life of roll neck bearings does not only depend on their quality. It will also be affected by mounting of the bearings. Therefore, the technical requirements and guidelines should be strictly .

1.Preparations for mounting

i.Before mounting of the bearings, the mating parts and adjacent parts, including roll necks, bearing housing, sleeves, and covers, etc., should be checked for dimensional accuracy, geometrical accuracy, and allowable tolerance in accordance with the technical requirements.

ii.The surface of the mating parts, in other words, roll necks, bearing housing bore, lubrication ports, must be cleaned and filled with lubricants. All burrs and sharp edges must be removed.

2.Mounting of four-row cylindrical roller bearings

i.Installation of the labyrinth rings

The labyrinth ring and the roll necks are usually shrink fitted. The ring should be tapped lightly onto the roll neck with a brass rod. The labyrinth ring should be clamped onto the roll body without a gap.

ii.Installation of the inner rings

The inner ring should be tightly fitted on to the roll neck by shrink fitting. The inner ring should be heated to 90℃~100℃. The heated temperature should not exceed 120℃, or the inner ring may not shrink completely after cooling. The heating is carried out by induction heating devices, or in an oil bath. Direct flame should be forbidden for heating of the bearings.

iii.Installation of the outer rings

The outer rings of four-row cylindrical roller bearings normally have a sliding fit in the bearing housing. Smaller outer rings can be tapped into the housing lightly by a brass rod. Large bearings can be lifted into the bearing with a crane.

iv.Installation of axial bearings

Axial bearings, such as four-point contact ball bearings, angular contact ball bearings, deep groove ball bearings and thrust tapered (or cylindrical) roller bearings, should not be subjected to any radial load. The bore of the housing should be 0.5mm larger than the outside diameter of the axial bearings. Or the roll neck diameter should be 0.5 mm smaller than the inner diameter of the bearings. For four-point contact ball bearings, the spacer of same model should not be interchanged, or it will change the axial clearance. For thrust tapered (or cylindrical) roller bearings, the interchange of spacers for the same model will change the radial clearance of the bearings and therefore should not be allowed. The inner ring side faces of the axial bearings must be pressed tightly in installing in order to fix the bearings on axial position. This will stop the bearings moving and preventing abrasive wear and heat damage.

The axial bearings are positioned by the bearing housings and the axial clearance should be adjusted. The inner ring and outer ring of the axial bearings should be fully abutted against the inner ring and outer ring of the main bearings during the mounting of the bearing housings. The axial moving of the bearing housings must be avoided when the bearing housings are mounted onto the roll necks.