Types of Bearings
Bearings are components used to reduce friction between moving parts and can be found in applications ranging from household items such as fans and washing machines to high-performance machinery, including aircraft engines and race cars. Several types of bearings are available, making it vital to understand the differences between the types and which works best for a particular application.
Ball Bearings
Ball bearings are among the most common type of bearings and are available in a variety of sizes and designs. This type of bearing consists of a plate with two inner rings, in which two hardened steel balls of equal size rest. As one ring rotates against the other, the balls roll, greatly reducing the friction between the two surfaces. Ball bearings are incredibly versatile, enabling their use in heavy load, high-velocity and low noise applications.
Roller Bearings
Likewise, roller bearings are very similar to ball bearings. However, instead of using spherical balls, roller bearings feature cylinders. Such cylinders are available in a variety of sizes and lengths, including cylindrical and conical designs, for different load-bearing capacities. This type of bearing has a more complicated construction than ball bearings, but can also handle heavier loads and greater velocities than ball bearings.
Cage Bearings
Cage bearings are designed for applications that require high loads and moderate speeds. These bearings use pockets of steel to separate the balls, which are used in place of cylinders. This reduces the contact between two dynamic surfaces, while allowing the bearing to support both axial and radial loads. The pockets also minimize the impact of the ball bearings, enabling their use in several applications.
Needle Roller Bearings
Needle roller bearings are elongated cylindrical rollers that are used to reduce friction in high-stress applications. In developing this type of bearing, engineers were able to construct a bearing that was much smaller than its cylindrical counterpart. Since they can withstand higher loads than other bearings, needle roller bearings are often used in highly-dynamic applications, such as transmissions, pumps, and electric motors.
Magnetic Bearings
Magnetic bearings are a relatively recent addition to the bearing world. This type of bearing uses magnetic fields to reduce the contact between two moving parts, eliminating the need for lubricants. Magnetic bearings are incredibly light and can be used for ultra-high speed applications, such as turbines. Exam recent development in this field allows for the use of electromagnetic bearings, which eliminates the need for rolling parts.
Tapered Roller Bearings
Tapered roller bearings are designed for applications that require high speed and heavy loads. This type of bearing consists of tapered roaders arranged in a conical shape. Each of these rollers is cut with a specific angle and taper, allowing them to remain in contact with each other during operation. This reduces friction, allowing the bearing to remain in good condition, even when used with high speeds and heavy loads.
Additional Types
Along with the types of bearings described above, several additional variations are available. These include thrust or axial bearings, sleeve bearings, spherical roller bearings, double row bearings, and split bearings. Each of these offers a variety of advantages, which make them suitable for different applications. However, knowing which bearing is best for a particular application can be difficult and often requires the help of an experienced engineer.
