There are three main reasons for bearing failure; bearing fatigue, incorrect lubrication and the wrong selection of bearing type and material. Addressing these three points when choosing what bearing should be used in each application is crucial, and could help designers to make the right decision.
The most important consideration is the type of bearing to suit the application. There are many types to choose from, including plain bearings, ball bearings, roller bearings, needle bearings to name a few. Each of these types has many variations; for example, plain bearings can be sintered, wrapped, plastic, composite or machined from various solid materials. Ball, roller and needle bearings can be offered in numerous configurations.
The majority of customers know exactly what their bearing needs to do. They know the load, speed and environmental requirements, but need advice on what type of bearing can deliver those capabilities most effectively, most cost-efficiently.
This will influence not just the cost of the initial purchase, but potentially other factors including the cost of ongoing maintenance, lifespan of the bearing and even how efficiently the equipment works.
In some cases, there are clear benefits to using an alternative bearing type. The new Bowman BowMet range, for example, can take higher loads and can withstand corrosion so it is being used successfully to solve the corrosion problems faced with rolling element bearings, whilst also giving higher load capabilities. In some cases prices are also lower – a win-win situation.
This is where a whole-market manufacturer and supplier, not restricted to any single type of bearing like some suppliers, can add real value through independent advice.
The choice of material is another important decision that has to be made. Plain bearings are manufactured in sintered bronze, sintered iron, copper, rolled bronze, cast bronze, various plastics, various composites, stainless steel and other alloys such as BowMet, which is made from the ToughMet alloy.
Ball, roller and needle bearings can be offered in high carbon chrome steel, stainless steel, plastic and other materials. To make things even more complex, the bearing industry rarely stands still. New materials are being developed all the time which can improve the life, load and corrosion resistance of bearings. Take the new BowMet range for example, which is manufactured from the copper/nickel/tin ToughMet alloy, developed by Materion in the USA. This new material is revolutionising the use of wrapped bearings due to its enhanced capability to take far higher loads and is corrosion free – thus giving longer life and greater reliability.
Serious consideration also needs to be given to lubrication because bearing life needs to be as long as possible, with no – or minimal – maintenance. Indeed, maintenance is becoming more and more important, and bearings should preferably be maintenance-free. Considerable thought must be given to speed, loads, corrosion and of course, maintenance.