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Bearing (mechanical)

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A bearing is a vital machine element designed to control motion. It constrains relative movement so that parts move only in a desired direction. Most importantly, a bearing reduces friction between moving components. The name comes from the verb "to bear," meaning to support.

Ball Bearing2
Ball Bearing2

By supporting one part with another, bearings allow for smooth rotation or linear movement. They can even prevent certain motions by controlling the normal forces applied to parts. Without them, many machines would seize up due to heat and wear.

Bearings work through several distinct mechanical principles. The simplest version is the plain bearing. This consists of a shaft rotating inside a hole or a sleeve. To minimize sliding friction, engineers often add a lubricant. This lubricant can be a liquid, a solid, or a gas.

BallBearing
BallBearing

Another method uses rolling-element bearings to achieve low external friction. These use balls or rollers with circular cross-sections. These elements sit between two surfaces called races or journals. Instead of sliding, the parts roll, which significantly reduces resistance.

There are many specific types of bearings used in engineering. Rotary bearings hold rotating parts like axles and transfer loads to a supporting structure. These loads can be radial or axial. Some rolling-element bearings use a cage to hold each ball or roller. This prevents the elements from rubbing against each other.

Ball Bearing2
Ball Bearing2

Other specialized designs include tapered roller bearings, which use cone-shaped rollers. There are also self-aligning bearings that can adjust to slight misalignments. Even more modern versions include wire race bearings, which have very small cross-sections.

The history of bearings spans thousands of years. While some speculate Egyptians used wooden rollers under sleds, there is no archaeological evidence. However, Egyptian drawings show plain bearings used in hand drills. Wheeled vehicles using plain bearings appeared between 5000 BC and 3000 BC.

Шарикоподшипники
Шарикоподшипники

A wooden ball bearing was recovered from Roman Nemi ships dating to 40 BC. Leonardo da Vinci included ball bearing drawings in a helicopter design around 1500. In the 1740s, John Harrison invented the first practical caged-roller bearing for his H3 marine timekeeper.

Many inventors shaped the modern bearing industry. Philip Vaughan received the first ball bearing patent in 1794. In 1869, Jules Suriray patented a radial-style bearing for bicycles.

Early Timken roller bearing
Early Timken roller bearing

In 1883, Friedrich Fischer developed machines to grind balls to exact roundness. This allowed for the creation of a massive bearing industry. Henry Timken patented the tapered roller bearing in 1898. Later, Sven Wingquist patented the self-aligning design in 1907.

Wingquist patent PRV 25406 1907b
Wingquist patent PRV 25406 1907b

These advancements were essential for the success of the Industrial Revolution.

Materials choice is critical for bearing performance. Early bearings were made of wood or bronze. Today, they are made from a vast array of substances. Chrome steel is common because it is hard and resists wear.

Early Timken roller bearing
Early Timken roller bearing

Stainless steel is used when high corrosion resistance is needed. Ceramics like silicon nitride are lightweight and handle high heat well. Even plastics like nylon or Teflon are used for low-speed or lightweight tasks. Watchmakers even use sapphire to create "jeweled" bearings for precise timekeeping.

Modern bearings are found in almost every moving system. They enable the high speeds required for dental drills. They are even used in the Mars Rover for aerospace applications.

Ball Bearing2
Ball Bearing2

You can find them in automobile gearboxes and wheels. They also allow for precise movements in optical alignment systems. From tiny watches to massive industrial machines, bearings make modern technology possible by managing the forces of motion.

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🖼️ Images & Media (6)
File:Ball Bearing2.jpg
Ball Bearing2.jpg
File:Tapered steering head bearings.jpg
Tapered steering head bearings.jpg
File:Шарикоподшипники.jpg
Шарикоподшипники.jpg
File:Early Timken roller bearing.jpg
Early Timken roller bearing.jpg
File:Wingquist patent PRV 25406 1907b.png
Wingquist patent PRV 25406 1907b.png
File:BallBearing.gif
BallBearing.gif
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