Why Bearings Fail - And How To Prevent It

Though it is a fact of life that things will break at some point, it doesn’t mean that you can’t delay the inevitable breakdown. Bearing failure is a common problem, so we decided to write up a guide on nine common reasons your bearings are failing and what you can do to increase the longevity of your bearings.

1. Lubrication Failure

According to a recent study, up to 80 per cent of bearing failure is caused by improper lubrication. This includes too much, or too little quantities of product applied, using unsuitable lubricants or working the bearings at excessive temperatures.

What to look for

Look for discolourings such as brown or blue colours on your rolling elements and rolling element tracks. Discolouring is usually a sign that something is not right.

How to Fix it

Make sure you use a high-quality lubricant with the right specifications. Sometimes spending a little bit more on the correct type of product can turn out cheaper in the long run if it helps to keep your bearings in good shape. Also, make sure to apply the correct amounts.

2. Contamination

Foreign substances can contaminate your lubricant. Dirt, abrasive grit, dust, steel chips, water from work environments can all transfer to the product damaging your bearings.

What to Look for

Watch for denting of rolling elements and raceways that cause vibration.

How to Fix it

Clean work areas, tools, fixtures and hands to reduce the risk of contamination. Be sure that the lubricant is fresh and clean, with no visible particles in the solution. Have a look at our cleaning range for some products that may help.

3. False Brinelling

Movement while the equipment is idle, wears away at the lubrication. While the lack of rotation in the bearing can make it difficult for the lubricant to reach the areas it is needed resulting in false brinelling.

What to Look for

Look for linear wear marks in the axial direction of the rolling-element pitch or a lack of raised edges due to incorrect mounting.

How to Fix it

Eliminate or absorb external vibration that can make the balls to move. Be sure to use lubricants containing anti-wear additives.

4. Corrosion

Low-quality grease, poor wrappings and condensation can cause corrosion which can damage the balls and rolling elements.

What to Look for

Look for red and brown stains and deposits on rolling elements, raceways and cages. As well as increased vibration, increased radial clearance or loss of the preload.

How to Fix it

Make sure to use the correct lubricant. Divert corrosive fluids away from bearing areas and select integrally sealed bearings. Using proper bearing materials, such as stainless steel, can help if you cannot avoid a corrosive environment.

5. Fatigue (Spalling)

Spalling is often the result of overloading, tight inner-ring fits or using the bearing beyond its lifespan.

What to Look for

Look for small fractures on the running surfaces of the bearing as well as material shedding from the inner and outer ring, and rolling elements. Spalling is progressive and will continue to spread if not addressed early. An increase in vibration and noise is also another indicator.

How to Fix it

Replace the bearing or consider a redesign that uses a bearing with higher fatigue life, internal clearances, and proper shaft and housing recommendations. Also, use high-quality greases.

6. Overheating

Overheating is the result of excessive operating temperatures and improper lubrication. High temperatures cause greases to bleed, which reduces the lubricant’s efficiency. High-temperature conditions also cause oxidation which can damage the grease, leaving a dry, soap-like substance that can seize the bearing.

What to Look for

Look for any discolouration of the rings, rolling elements and cages. In extreme cases, the bearing components will deform. High temperatures can also degrade or destroy the lubricant.

How to Fix it

Look at all options to reduce the temperature and overheating.

7. Excessive Loads

A heavy load is another common way to damage a bearing.

What to Look for

Look for signs of wear of the rolling elements, evidence of overheating and areas of fatigue.

How to Fix it

Use high quality, extreme pressure greases and reduce the load. Consider a redesign using a bearing with higher capacity.

8. Improper Storage and Handling

Improper storage exposes bearings to moisture and dust. Storing bearings in excessively high temperatures can also degrade a grease’s shelf life, so always check with the grease manufacturer for storage specifications. Opening boxes and wrappings prematurely can expose the bearing to dirt and corrosive elements.

What to Look for

Look out for dampness and high temperatures that can cause rust and inspect the storage of bearings.

How to Fix it

Store bearings at room temperature in a dry place. Always cover bearings to keep them clean while in storage and take them to the installation site before unwrapping.

9. Fit

Excessive loading is usually the cause for too tight a fit.

What to Look for

Look for wear at the bottom of the raceway, overheating or an inner-ring axial crack. For a loose fit, note any fretting, which leaves a distinctive brown colour. Wear at the fitting surfaces can cause noise and runout problems.

How to Fix it

Make sure a proper clearance is selected to avoid fit issues. Refer to the manufacturer’s installation guide.

Being aware of your working environment and carrying out regular preventive maintenance can keep your bearings at peak performance for as long as possible, saving your business time and money. To help look after your bearings have a look at our range of high quality greases and lubricants