Ball Bearings


A ball bearing is a type of rolling element bearing which employs balls to maintain separation between moving parts of a bearing. These ball bearings are used to reduce and minimalise the rotational friction and the axial and radial loads. Ball bearings achieve this by using at least two races, which contain the balls and transfer any loads through the balls. Sometimes one of the races is fixed into place.

As one of the races turns/rotates the balls rotate as well and because the balls are rolling they have a much lower coefficient of friction. It is the small surfaces of the balls between the races that allow them to have a lower load capacity for their size. The low cost of producing the ball bearing makes it less expensive than other types of bearing.

There are many different types of ball bearings mechanisms available for various applications and these can include:

• Aircraft bearing: A term generally applied to bearings used by the aircraft industry or the Air Force.
• Airframe bearing: A bearing designed for use in the control systems and surfaces of aircraft.
• Angular contact bearing: A type of ball bearing whose internal clearances and ball race locations as such as to result in a definite contact angle between the races and the balls when the bearing is used.
• Anti friction bearing: A commonly used term for rolling element bearing.
• Ball bearing: A bearing using balls as the rolling element.
• Ball cage: A device that partly surrounds the balls and travels with them.
• Ball complement: Number of balls used in a ball bearing.
• Cone: Inner ring of tapered roller bearing.
• Double row bearing: A bearing of two rolling elements.

Uses for ball bearings are vast and some typical applications can include:

• Automobile wheels
• Washing machine drum bearings
• Bicycle wheels
• Dental equipment
• Machine tools; drills, centre lathes, milling machines etc.

Other types of bearings have also been developed such as fluid bearings. These fluid bearings do not use steel balls like the more conventional ball bearing, but instead support the bearings load on a thin layer of liquid or gas. This type of bearing is generally used in computer hard drives.

Other fluid bearings include; foil bearings, Air bearings, and journal bearings.