Table of Contents
Choosing the correct bearing for machinery and equipment is essential for optimal performance and longevity. Accurate calculation formulas help determine the appropriate bearing type and size based on load, speed, and operating conditions. This article explains key formulas used in bearing selection.
Basic Bearing Load Calculations
The fundamental formula for bearing load capacity considers the applied load and the bearing’s dynamic and static load ratings. The basic equation is:
F = C / (k × n)
Where F is the applied load, C is the dynamic load rating, k is a factor based on operating conditions, and n is the number of bearings sharing the load.
Speed and Life Expectancy Formulas
Bearing life expectancy is calculated using the L10 life formula, which predicts the number of hours a bearing will operate before 10% of a group fail. The formula is:
L10 = (C / F)³
Where L10 is the bearing life in millions of revolutions, C is the dynamic load rating, and F is the applied load.
Calculating Contact Stress
Contact stress influences bearing durability. The Hertzian contact stress formula is:
σ = (F / A)
Where σ is the contact stress, F is the load, and A is the contact area. Proper calculation ensures the bearing can withstand operational forces without excessive wear.
Summary
Accurate bearing selection depends on understanding load capacities, life expectancy, and contact stresses. Applying these formulas helps ensure the chosen bearing meets the specific demands of the application.