How to wear it well: optimizing bearing performance

Maintaining equipment integrity is crucial across a wide range of industries and manufacturing applications. It’s especially important to keep bearings in good working order, since they minimize friction between moving parts, allowing for smooth and efficient operation of machinery.

Exploded view of a Regal Rexnord Sealmaster SS Gold bearing.

Reduction of friction helps conserve energy and lessens the wear and tear on components. It also enables the high speeds and heavy load capacities often required in demanding environments, ultimately ensuring productivity and longevity of the equipment.

Maintaining reliable bearing operation depends on multiple factors, including proper part selection, handling, installation, and maintenance. If you are experiencing bearing wear in your applications, it’s important to understand the types of bearing wear to determine the possible causes and how best to prevent it.

What typically causes bearing wear?
Short bearing life is most often the result of issues related to lubrication, contamination, installation, misalignment, shaft lock, or other application factors. The need for rigorous cleaning processes in certain industries also presents a significant challenge to equipment longevity and can accelerate bearing wear and tear that leads to premature failure.

Wear can occur from a single cause or from multiple causes, so be sure to consider all the possible reasons. It may take experience to correctly identify and resolve the root cause, especially when multiple types of wear are present.

Cross section of a Sealmaster SS Gold seal.

 Common Types of Bearing Wear
This list of common types of bearing wear covers typical forms that can occur, along with frequent causes and tips for prevention.

 Frosting: Also known as micro-spalling, it is a common form of wear that is typically observed in bearings over time. The frosted appearance can be due to adhesive or abrasive wear to the material surface caused by insufficient lubrication film thickness and/or fine contamination. Continued use may result in surface-initiated spalling.

• Possible causes: Inadequate lubricant properties, lubrication breakdown, ineffective re-lubrication, and contamination
• How to prevent it: Review lubrication selection; review re-lubrication frequency, amount, and procedure; review seal selection

Surface Initiated Spalling: Metal fatigue that develops at a material surface that has worn, deformed, or been damaged. The metal flaking that occurs is a secondary form of wear due to stress concentrations at existing wear locations.

• Possible causes: Wear or debris denting, brinelling or false brinelling, inadequate lubricant properties, ineffective re-lubrication
• How to prevent it: Determine initial source of wear; refer to appropriate prevention for source of wear; review lubrication selection; review re-lubrication frequency, amount, and procedure

Fretting: This form of wear is initially an adhesive wear between two surfaces in contact (such as the inner ring bore and shaft) experiencing movement or vibration. As the surfaces wear, continued movement or vibration results in adhesive and abrasive wear. Oxidation or corrosion may occur on the worn surfaces.

• Possible causes: Vibration; minute relative movement of surfaces; excess clearance between bearing and mating components
• How to prevent it: Reduce system vibration and imbalance; review shaft and housing fit-up

Loss of Lock: Scratching, gouging, and general wear observed in the bore of an inner ring and outside diameter of a shaft are indications of loss of lock. Often, the set screw tips will also be worn. Fretting wear can sometimes be present on the surfaces and a precursor form of wear prior to the loss of lock.

• Possible causes: Improper tightening of locking mechanism; shafting undersized, worn, or damaged; hardened or stainless shafting reducing set screw penetration or holding; frequent start/stop operation
• How to prevent it: Ensure proper installation; use calibrated torque wrench; verify shaft tolerance, replace worn shafting; consider alternate locking mechanism

Misalignment: Wear present on the raceways traveling from side to side due to improper alignment at installation or machine operating characteristics. Static misalignment creates a fixed skew between the inner and outer rings. Dynamic misalignment creates a variable skew due to system imbalances.

• Possible causes: Shaft or housing misalignment; uneven mounting surfaces; frame distortion or flexure; bent or deflecting shaft; system imbalance
• How to prevent it: Review alignment at installation; mounting surfaces should be clean and flat; replace damaged shafting; review bearing selection

Corrosion: Deterioration of material properties due to a chemical reaction. The rate and type of corrosion depends on many factors such as material, chemical, temperature, and contact method. Proper bearing selection should balance corrosion resistance with material strength, durability, sealing, and lubrication.

• Possible causes: Insufficient sealing, inadequate lubricant properties, ineffective re-lubrication, material selection
• How to prevent it: Review seal selection; shield or cover bearing to minimize contact with moisture; review lubrication and bearing selection; review re-lubrication frequency, amount, and procedure

7 Tips for identifying and preventing bearing wear

Sealmaster bearings from Regal Rexnord.

Here are some key best practices to follow that help operations identify and prevent bearing wear in industrial applications for optimized performance and life. Regular monitoring of system parameters can help identify bearing wear early.

1. Regular inspection: Implement a routine inspection schedule to check for signs of wear, such as noise, vibration, and increased temperature.
2. Proper lubrication: Ensure bearings are adequately lubricated with the correct type and amount of lubricant. Regularly check and replenish lubricant levels.
3. Effective sealing: Use high-quality seals and replace them as needed to prevent contaminant ingress. Look for bearings with advanced sealing technology, which are especially helpful for bearings in washdown environments.
4. Product selection: Choose bearings made from corrosion-resistant materials, such as stainless steel, for applications involving exposure to corrosive substances. Also, look for bearings that are specifically engineered to withstand high pressure and high temperatures for applications where those are used.
5. Correct installation: Proper installation is crucial to prevent premature wear. Follow manufacturer guidelines for mounting, alignment, and preload.
6. Vibration and temperature monitoring: Implement vibration monitoring systems to detect early signs of bearing damage. Also, monitor bearing temperature to identify overheating, which can indicate lubrication issues or excessive wear.
7. Training: Train personnel on proper handling, installation, and maintenance procedures to minimize the risk of damage.

Optimizing bearing performance
Understanding the causes of bearing wear and implementing preventive measures can help operations significantly extend bearing life, reduce downtime, and improve overall operational efficiency. Choosing the right bearing for the application and adhering to best practices for maintenance are essential for ensuring reliable performance and minimizing the total cost of ownership.

Regal Rexnord
www.regalrexnord.com

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