Factors to Consider When Selecting Bearings for Heavy Equipment

Understanding the Load Conditions

Radial Loads, Axial Loads, and Combined Loads: Heavy equipment typically experiences high radial (lateral) loads, and sometimes axial (thrust) loads.
Impact Loads: Construction and heavy machinery are frequently subjected to sudden loads or impacts. A “service factor” or safety margin should be used when determining dimensions.
Torque Loads: For rotating structures (such as the slewing bearing of an excavator), bearings must withstand torque loads as well as radial/axial loads.

Bearing Type/Geometry

Depending on your load and alignment conditions:

Spherical Roller Bearings: Suitable for misalignment and applications with large radial and axial loads.
Tap Roller Bearings: Suitable for applications with combined radial and axial loads.
Cylindrical Roller Bearings: Ideal for extremely high radial loads.
Self-Lubricating/Slippery Bearings: Self-lubricating bearings are very useful in very dirty or low-maintenance environments. Fit/Installation (Interference Fit/Press Fit)
For heavy loads, interference fits/press fits are typically used to prevent bearing slippage on the shaft or within the housing.
However, note that: an overly tight fit may damage the bearing; an overly loose fit may cause unnecessary movement. Proper installation techniques are crucial (e.g., for large bearings, a press or thermoforming method can be used).

Clearance and Tolerances
Internal clearances in bearings compensate for thermal expansion, deflection, etc. Tolerance Grades: Depending on your precision and alignment requirements, you may need tighter or looser tolerances.
Lubrication
High loads generate more friction and heat, so choosing the appropriate lubricant (grease or oil) is essential.
In some applications, self-lubricating bearings (e.g., bronze + graphite) reduce maintenance.
Also consider using seals or protective covers to prevent contaminants (dust, water) from entering.
Operating Environment
Heavy equipment often operates under harsh conditions: dust, mud, humidity, and wide temperature variations.
Use bearings with good sealing/corrosion resistance when necessary.
Material selection is crucial: Standard steel is typically used, but sometimes treated/coated or special materials are employed to enhance durability.
Bearing Life and Reliability: Use the dynamic and static load ratings provided by the bearing manufacturer and estimate bearing life (L10 life) based on your load, speed, and operating conditions.
DFL NSAR Bearings offers a full range of high-quality stamped bearings, roller bearings, and ball bearings designed to meet the demanding requirements of heavy equipment and industrial machinery. Whether your equipment is subjected to radial, axial, or combined loads, our bearings ensure smooth operation, durability, and long-lasting performance, even in harsh environments.