A single car has about 30,000 components, from major body structures down to individual bolts and screws. Every part has an integral role in keeping a car running, and this goes for bearings too. In a vehicle with a conventional engine, there will be on average around 100 to 150 bearings, many of which are key in reducing friction and energy expenditure and ensuring safe operation. In this article, Chris Johnson, managing director at specialist bearing supplier SMB Bearings explains the importance of automotive bearings.

When considering the important parts of a car, bearings are often overlooked, but incorrect or faulty bearings can cause noise and friction, and even increase emissions and impact customer experience. Bearings are present in many vehicle components, and the type and size will depend on the requirement. Car parts and their functions are so varied that their bearing requirements differ significantly too. Several types of bearing are used depending on many factors, such as the radial load, the axial load and the operating condition.

Bearings are found throughout all vehicle types. From the air conditioning systems and water pumps to seat and mirror adjustment mechanisms, many of a car’s important functions would be far less effective or even impossible without the use of bearings. Cars powered by internal combustion engines have significant amounts of moving parts making bearings are integral in the smooth running of components such as alternators, power steering and gearboxes. Demand for electric motor bearings is also growing as electric vehicles (EVs) become increasingly popular, with lighter, smaller bearings important in improving EV drive train efficiency.

Selecting the appropriate bearing for automotive applications is important to optimise vehicle performance, to ensure safety, and to reduce emissions. Above all, buyers should consider quality and reliability. Choosing the correct bearing size and material can make all the difference to driver experience by ensuring fluid motion and reducing noise.

Bearings used in automotive applications must withstand harsh conditions and long periods of stress under heavy loads, so material choice is of the utmost importance. Throttle valve bearings, for example, are key in regulating air flow, and are exposed to high vibration levels and extreme temperatures. For these applications, ball bearings and plain bearings have been traditionally used but sealed needle roller bearings are becoming increasingly popular due to the greater tolerance to vibration.

Longevity is also a consideration — bearings are often fitted for the life of the component, but faulty or worn bearings can produce noise or reduce efficiency and may need replacing at fixed intervals. Maintenance can be kept to a minimum by choosing a bearing guaranteed to last for the recommended service life. Buyers can look out for ISO/TS16949 compliant bearings to ensure that the products meet the internationally recognised quality management standard for the automotive industry.

Effective bearing performance doesn’t just stop at the bearing itself — lubricant choice is also a factor and can alter effectiveness. Wide temperature greases are suitable for general automotive use due to the range of temperatures that automotive bearings are exposed to. Dampening greases reduce noise and vibration in slow moving steering column bearings, though they are also widely used in other applications to minimise rattles and squeaks or give a quality feel. This type of grease can be found in seat guides, sunroofs, central consoles, dials, slides, switches, cup-holders, power mirrors and locking systems.

Each of the thousands of car parts is essential to performance, and bearings should not be overlooked. Automotive bearings are integral to safe and reliable vehicle function, and in improving efficiency in both conventional and electric motors. When choosing bearings, buyers should make bearing choices with quality in mind to guarantee optimum performance.