Rolling Bearings Terminology and Definition
Rolling bearings are used in a variety of industrial applications, from conveyors to pumps and more. The terminology associated with rolling bearings can be confusing to those unfamiliar with them. In order to better understand these bearings, it is essential to know the key terms and definitions associated with them.
1. Cage: The cage, sometimes referred to as the ‘retainer’, is the metal ring surrounding the rolling elements to help keep them in their correct position and spaces.
2. Clearance: Clearance refers to the amount of space between the rolling elements and the inner and outer bearing rings. Clearance is typically expressed either as a positive or a negative number. A negative number indicates a greater clearance, whereas a positive number indicates a smaller clearance.
3.Gap: Gap is the measured distance between the two bearing rings. This measurement is used to ensure that the rolling elements can move freely and operate as expected.
4. Rolling Element or Rolling Element Bearing (REB): These are components that spin in relation to the stationary bearing rings. They are typically made of metal, but can also be plastic. Examples include ball bearings and roller bearings.
5. Roller: A roller is a cylindrical rolling element, usually made of metal. Roller bearings are used in low speed applications and offer high load capacity.
6. Pitch: Pitch is the distance between the raceways of a single row of rolling elements in a bearing.
7. Raceway: The raceway is the part of the bearing which contains the rolling elements.
8. Seal: The seal is a device used to keep lubricant and particles from entering the bearing and contaminating it. It also helps shield the bearings from dirt and debris.
9. Thrust Bearing: A thrust bearing is a specific type of bearing that is designed for applications that require thrust or axial loading.
10. Waviness: Waviness is the undesired oscillation in the rolling elements of the bearing. This can result in decreased load capacity and higher temperatures.
11. Contact Angle: The contact angle of a bearing is the angle between the two rolling elements as they move through the bearing. This measurement is used to determine the speed and rotational torque of the bearing.
12. Preload: Preload is a method of applying additional force to the inner and outer bearing rings that increases the separation of the rolling elements. This can help reduce bearing noise and vibration, as well as increase rolling element life.
13. Pitch Diameter: The pitch diameter of a rolling bearing is the diameter of the circle over which the rolling elements move. This measurement is used to calculate the bearing’s load capacity.
Rolling Bearings are an essential component in a variety of industrial applications. Knowing the terms and definitions associated with them is essential for properly selecting, installing and maintaining them in order to achieve optimum performance and life.
