Control of Material Factors Affecting Bearing Life
Bearings are essential components in machines. Whether a machine works reliably or not largely depends on the performance of bearings. Bearing life is an important criterion for evaluating their quality and level of performance.
There are many influencing factors for bearing life, such as structure and size, loading conditions, rotating speed, lubrication status and the contact stress, but mostly the material characteristics. The material characteristics can be expected, measured and controlled by customers.
Material selection for bearing components is of great importance for its life. The selection must take into account the type and load range, as well as the operating environment and conditions. The design of bearings must consider the material characteristics. The life expectation of the bearings can be increased by selecting the most suitable material.
Since the performance of bearings is affected by the thermal expansion, deformation and fatigue of the components, the bearing material must have a sufficient resistance to its forming and some specific characteristics such as strength, hardness and resistance to wear, to ensure its reliability and durability.
In a word, bearing materials should have low coefficient of friction, appropriate hardness, wear-resistance, fatigue-resistance and good stability in heat treatment. This governs the stability and performance of bearings as well as the consequent working reliability and service life.
In ordinary pattern bearings, steel is used as the base metal. The steel is first heat treated to give it the requisite hardness and then machined. The heat treatment and machining have a significant effect on bearing life. Steel control is done to maintain the requirement of high accuracy, surface integrity and fatigue strength.
Bearing life can be prolonged if superior grades of bearing steel are applied or if the steel employed possesses good surface integrity. Therefore the better the quality of the steel the longer the life of the bearing could be.
The surface roughness of the bearing component is also an important factor affecting the bearing life. Bearing failures are often caused by surface defects that include pits, cracks and scratches. Consequently interior surface finishing plays an important part in ensuring the bearings performance and longevity. Poor surface finishes lead to an early bearing failure.
It follows as a primary consideration that if you are controlling your material, your bearing life will be improved. Realizing the outmost important role of material controls, customers should track the material characteristics of their components throughout the production process.
It should also be noted that different sealing solutions are available. The most efficient sealing system depends on the environment in which the bearing operates, the dust, temperature etc.
Careful observation of bearing component features and operating conditions can help to obtain the best repeatable performance of the product. The maintenance of clean bearing bears witness to the impact of proper material selection.
It is highly likely that bearing life could be extended if careful material selection and finishing were undertaken and appropriate attention was given to the design of the component, speed, components fit, lubrication and proper selection of seals. Material controls are the key to ensure the quality and performance of bearings available in market.
