Question

All else being equal, for rolling element bearings, which is more damaging?

		They are equivalent.
		outer ring rotation.
		Stop worrying--they're both fine!
		inner ring rotation.

Answer 1

Rolling element bearings

• It is a bearing carries a load by placing rolling elements between two bearing rings called races.
• Rolling elements to roll with very little rolling resistance and with little sliding. A rolling element rotary bearing uses a shaft in a much larger hole and cylinder called rollers tightly fill the space between the shaft and hole.
• Advantages - Good trade of between cost, weight, carrying capacity, durability, size, accuracy, friction and much more.

Damages in rolling element bearings

• Sometimes minor problems cause bearings to fail quickly.
• Vibration based analysis can be used for fault identification of bearings.
• Bearing without lubricant, even though it is not rotating and thus is apparently not being used.
• 3 usual linits to the lifetime/ load capacity of a bearing - abrasion, fatigue and pressure induces welding.
• Fatigue results when a material become brittles after being repeately loaded and released.
• Oil becomes the heat sink for friction loss generated by the bearing. Oil flow also reduce the bearing metal temperatures.
• Uneven running
• Damages bearings rings.
• Improper handling and installation of rolling element bearings.
• Vibration and impact of the moving surface of a bearing under high pressure conditions effect the cage life.