Full definition
Bearing relubrication is a critical maintenance process aimed at ensuring that in-service bearings maintain an adequate lubricant film to function effectively. This process prevents overheating, wear, and premature failure of bearings, which can occur when lubrication is insufficient. Regular relubrication is vital, especially in environments subject to high loads, speeds, and varying temperatures. The relubrication interval is determined using the SKF formula: tf = (14,000,000 / n√d) × k, where 'n' represents the operating RPM, 'd' is the shaft diameter in millimeters, and 'k' is a correction factor that accounts for temperature, position, and environmental conditions. This formula helps in estimating the appropriate time between relubrication sessions, optimizing the maintenance schedule to match operational demands.
The quantity of grease to be applied during relubrication is also crucial for maintaining bearing performance. The formula used to calculate the grease quantity is Gg = 0.005 × D × B, where 'D' is the outer diameter of the bearing and 'B' is its width. This calculation ensures that the right amount of grease is delivered, preventing over-lubrication, which can cause seal damage or excessive heat. Furthermore, adherence to standards such as ISO 281, which provides guidelines for the dynamic load ratings and life of rolling bearings, is essential for establishing reliable maintenance practices.
In practice, the relubrication process should be conducted with careful consideration of the bearing's operating environment and the type of grease used. Different applications may require specific lubricants, and using the wrong grease can lead to incompatibility issues, reducing the effectiveness of the lubrication. Regular monitoring of bearing temperatures and performance, along with maintaining proper relubrication intervals, contributes significantly to extending the service life of bearings in industrial applications.