What is a Bearing? Basic study
The current form of bearing was developed at the end of the 19th century. It was originally handmade.
Nowadays, bearings are one of the most commonly used mechanical parts because their rolling motion makes almost all movements easier and helps reduce friction.
Bearings have two key functions:
They transmit motion, that is, they support and guide components that rotate relative to each other
They transmit power
Rolling bearings and sleeve bearings
In a bush or sliding bearing, the shaft and the bearing move in opposite directions on the sliding surface. In contrast, the two close parts of a rolling bearing-the inner ring and the outer ring-are separated by rolling elements. The friction generated by this design is much smaller than that of sleeve bearings.
Radial bearing and axial bearing
Bearings can transmit loads in the radial or axial direction (thrust), and in many cases, both radial and axial loads are transmitted.
Both designs can provide ball bearings or roller bearings. The choice of bearing design depends on the application in question.
Bearings usually consist of the following components:
- Two rings or discs with raceways
- Rolling elements in the form of rollers or balls
- A cage that keeps the rolling elements separate and guides them
Inner ring/outer ring
The inner and outer rings are usually made of special high-purity chromium alloy steel. This material has the necessary hardness and purity-both important factors for high load ratings and long service life.
The raceway is hardened, ground and ground.
Special materials such as ceramics and plastics are also used. Although plastics cannot withstand extremely high temperatures, they are much lighter than steel. This makes them invaluable in industries where every gram is important (such as the automotive industry).
The rolling elements can be balls, rollers, cones, balls or needles. They are usually made of special high-purity chromium alloy steel. Special materials such as ceramics and plastics are also used.
The rolling elements roll on the specially designed ring or disk raceway, and are kept separate and guided by the cage.
Bearings are carefully designed and precision-manufactured components that enable the machine to move at extremely high speeds and easily and efficiently withstand huge loads.
Bearings must be able to provide high accuracy, reliability and durability, and be able to rotate at high speed with minimal noise and vibration.
Applications of bearings include automobiles, airplanes, computers, construction equipment, machine tools, DVD players, refrigerators and ceiling fans.
If something twists, turns, or moves, it may have bearings in it.
Bearing type and application
There are many different bearing types, and each type has special characteristics suitable for specific applications. The following are the four most common bearing types:
- The rolling function is provided by the ball
- Low friction, high speed, light to medium load
- Lightweight and general machine applications
Commonly found in applications such as fans, roller blades, wheel bearings, and under the hood of automobiles.
Cylindrical and needle roller bearings:
The rolling function is provided by a certain type of cylinder. It can also be called a needle bearing (the length is much larger than the diameter)
- Low friction, medium to heavy radial load
Usually found in general mechanical applications, including gearboxes and transmissions, machine tools and construction equipment.
Tapered Roller Bearings:
Tapered roller bearings are used for combined axial and radial loads, for example in truck wheel applications
Generally bear radial and axial loads in heavy industry, truck and wheel applications. Some examples are manual transmissions, gearboxes, power generation and other process equipment.
Spherical roller bearing:
- Roller bearings with barrel rollers.
- Medium friction, medium to heavy load and misalignment ability
- Typically used for ultra-high load applications where the shaft and housing are misaligned.