From research and root cause analysis for electric motor problems,the higher percentage came from bearing damage around 65%.That mean bearing is very important component in electric motor.
This time i want share about common types of bearing damage for electric motor and how to make a corrective action to avoid same problem happen again.Bearing usually can be used for a long period before their reaching the life span.
Bearing damage usually cause by improper bearing selection,no lubrication,rusty,corrosive,no greasing,wrong handling and due to types of application.Below i describe detail about types of bearing damage and how to prevent it from happen again.
What is the root causes for bearing damage?
1) Flaking
Description : Surface of the raceway and rolling elements peels away in flakes.Conspicuous hills and valleys form soon afterward
Causes : Excessive load,wrong handling,improper mounting,not precision in shaft or housing,rusty,contamination and no lubricating.
Corrective action : Select suitable type of bearing,Evaluate the clearance,review application method and check type of lubrication and method.
2) Crack / damage cage
Description : Rivets break or become loose resulting in cage damage.
Causes : Excessive load,speed to high,improper mounting,impact from foreign material,excessive vibration and no lubricating.
Corrective action : Select suitable type of bearing,evaluate the clearance,review service condition and check type of lubrication and method.
3) Rust and corrosion
Description : The surface becomes either partially or fully rusted, and occasionally rust even occurs along the rolling element pitch lines.
Causes : Storage condition not suitable,penetration by water,acid etc,handling with bare hand
Corrective action : Review storage condition,improve sealing condition,improve assembly method and handling.
4) Wear
Description : The surfaces wear and dimensional deformation results. Wear is often accompanied by roughness and scratches.
Causes : Foreign material in lubricant,not lubrication,life span,wrong alignment method
Corrective action : Review type of lubricant,check sealing condition and take a step to prevent alignment mistake.
5) Peeling
Description : Patches of minute flaking or peeling (size, approx. 10μm).Innumerable hair-line cracks visible though not yet peeling.(This type of damage frequently seen on roller bearings.)
Causes : Foreign matter in lubricant,not lubrication,wrong alignment method and type of lubrication.
Corrective action : Review type of lubricant,check sealing condition,take care for smooth operation and take a step to prevent alignment mistake.
Please let me know about brinelling of plain roller bearing
Couple small advises:
1) for drives with V belt (with several V belts it must) application better to use motors with NU bearing at DE (drive end). Otherwise every electric motor supplier must have ability to calculate, what type of bearings have to be in motor according every application conditions.
2) Usually one side bearing of induction motors is locked. If you use motor in vertical position, wrong side lock can cause fault of motor.
Ensure all technical details with electric motor supplier before purchase.
Thanks for the great advice :D