More about Bearings
Bearings are components that are used to reduce the amount of friction in a machine. The two most common forms of bearings are rotary bearings and linear bearings.
Linear bearings are used to permit motion in a straight line. For example, a drawer makes use of linear bearings to help pull the drawer in and out. Rotary bearings help an object move around a central point. For example, a wheel on a shaft rotates using rotary bearings. Rotary bearings can include one-direction rotation and oscillation. With oscillation, the rotary bearings only go through a part of a revolution.
Within these forms of bearings are bearings that utilize differing principles of design. One of these designs uses rolling element bearings, such as roller bearings and ball bearings. Rolling element bearings carry loads by placing a round element between two pieces. This causes the round elements to roll, or tumble, with very little sliding.
Another design of bearings is jewel bearings, which are commonly used in watches. Jewel bearings carry a load by rolling the axle slightly off-center. This causes the shaft to roll inside of the bearing instead of sliding. Natural jewels, such as ruby, sapphire, and garnet, were originally used in jewel bearings. Now, manmade rubies and sapphires are used instead.
Fluid bearings are another type of bearings. With fluid bearings, the load is carried by a liquid or a gas. Fluid bearings are used when a process requires high speed, high loads, or high precision, because ball bearings will wear out quickly in this application.
Magnetic bearings are used when a load is carried by a magnetic field. Magnetic bearings are often used to in electrical meters to measure power consumption. They are also used to support trains, resulting in a lower noise level and a smoother ride. Magnetic bearings create a very low amount of friction and can run without the use of lubrication. They can also run in a vacuum, but they are very costly.
Flexure bearings are used when the load element needs to bend. Typically, flexure bearings are just one part that joins two other parts. A door hinge is an example of flexure bearings. Flexure bearings are simple and inexpensive. They are usually lightweight and produce a low amount of friction, but their range of motion is limited and generally can’t support high loads.
Author：mosbearing 2008-7-18 Source: View(1095) Comment(0)