When installing the bearing, it is important to ensure that the bearing is as round as possible. This will optimize load distribution and promote the smoothest operation. The following procedures are recommended as an aid.
Use hardened round flat steel washers in accordance with ASTM F436 under the head of the bolt, and also the nut. Lockwashers, and locking compounds on the thread, are not recommended.
Install the washers, nuts and bolts in the bearing and supporting structure and hand tighten. Do not distort the bearing in order to install bolts. Apply a moderate centered thrust load to the bearing. Tighten the bolts to the equipment designer’s specifications. A common approach is to use a star pattern to tighten the bolts, sequences as shown in the diagram below. The pattern is usually done in 3 steps at approximately 30%, 80% and 100% of the final bolt torque or tension level specified by the equipment designer.
Loss of proper tension can lead to premature bolt failure, failure of the bearing and structure, damage to components, and fatality or injury to anyone in the vicinity. The bolts require frequent inspection for proper tension, which is commonly accomplished by measuring torque of the bolt.
