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Types of Bearings: How They Work? Parts, Uses [PDF]

In this article, you will learn about bearings it’s working, the classification of Bearings, different types of bearings, application of bearings & more.

Bearings and It’s Types

Generally, all types of machinery are provided with supports for rotating shafts, the supporting device is known as a bearing. In other words, a bearing is a machine element that constrains relative motions and is used to reduce the friction between moving parts.

Bearing employs to support, guide, and restrain moving the element. This is a stationary member and it carries the load.

Types of bearings

The part of the shaft supported by the bearing is known as the journal which is a moving member. Bearings are classified according to the type of operation they do.

  • The motions allowed, or
  • To the directions of the loads or forces applied to the parts.

The common applications of bearings are:

  1. Shafting in workshops,
  2. Spindles of a machine tool such as a lathe, drilling, milling machine, etc.
  3. The crankshaft of engines, and axles of automobiles, etc.

Classification of Bearings

There are three main classifications of bearings, according to the direction of load, viz.,

  1. Journal or radial bearing,
  2. Footstep bearing,
  3. Thrust or collar bearing.
  • A journal or radial bearing afford support to the shaft at a right angle to the shaft axis.
  • A footstep or pivot bearing support shaft parallel to the shaft axis and the end of the shaft rests on the bearing surfaces.
  • A thrust or collar bearing provides support to shaft subjected to end or axial thrust.

The surfaces of the bearing are generally flat or cylindrical. And they may consist of nonferrous metal surfaces known as bushes or hardened steel races supported by steel balls or rollers. In the above case, the bearing is known as bush bearings, and in the latter is known as a ball or roller bearings.

Types of Bearings

Following are the different types of bearings:

  1. Bush Bearing
  2. Thrust Bearing
  3. Foot Step Bearing
  4. Rolling contact or Anti-friction Bearing
  5. Ball bearing
  6. Roller bearing
  7. Plain bearing
  8. Linear bearing
  9. Fluid beaing
  10. Magnetic bearing
  11. Jewel bearing
  12. Flexure bearing

Read also: Gear Terminology: Basic Terms Used In Gear

#1 Bush Bearings

The simplest type of bush bearing is shown in the figure. it consists of a cast iron bearing block and a brass or gunmetal bush. In these types of bearings, The base plate of the bearing block provides holes for bolting down the bearing in position.

Bush bearing

At the top of the bearing, there is a counterboring oil hole that passes through the block and bush in facilitating lubrication of the shaft and the bush. It is used for the shaft which carries light loads and which rotate at slow speeds. In this type of solid bearing, the shaft may introduce and removed wisely.

In a bush bearing, there is a rubbing action between the outer surface of the shaft and the inner surface of the bearing. And the resulting friction minimizes by the presence of a film of lubrication oil. For line shafting, ring oiling may consider the safest and most efficient type under the ordinary condition of service.

Read also: Screw Thread Terminology and Types of Screw Threads

#2 Thrust Bearings

Thrust Bearings

In thurst bearing, the bearing pressure will be axial. The axis of the shaft may vertical or horizontal. If the axis of the shaft is vertical, the thrust bearing is known as footstep bearing. If the axis of the shaft is horizontal, the thrust bearing is known as a roller bearing.

#3 Foot Step Bearing

The figure shows a simple type of footstep bearing. It is suitable for supporting a vertical shaft. It consists of a cast-iron block and a gunmetal bush. The lower end of the shaft rests on a steel disc having concave seating.

Foot Step Bearing

In this type of bearing, the disc is prevented from rotating along and with the shaft by a pin inserting partly into the block and partly into the disc. The bush is prevented from rotating along with the shaft by the snug provides at its neck below the collar.

The main disadvantages of this type of bearing are that it is difficult to achieve effective lubrication. This type of bearing is generally used for slow-speed shafts carrying light loads. Generally, the vertical shaft is uncommon in the ordinary transmission of power. But they often occur on machine practice in machine tool turntables, textile machinery, etc.

#4 Rolling Contact or Anti-friction bearings

It is a well-known fact that a smooth rounded surface will roll over a similar surface more than when it is sliding. This phenomenon employs hard chrome steel balls or rollers to run in special design cages to provide bearings with low friction loss.

Rolling Contact or Anti-friction bearings

In this type of bearing, the motion between the shaft and the bearing surface is of pure rolling. Since the rolling friction is much less than the sliding friction. This type of bearing is known as antifriction bearing.

The outstanding feature of the antifriction bearings is their low starting frictions, which will practice the same while running also. This renders their application particularly suitable for machinery which has to frequently start, stop and restart.

#5 Ball Bearing

Ball Bearing
Image: Amazon.in

These consider the most common types of bearings. Ball bearings consist of a set of balls, they are located between two annular metal pieces, known as races. These bearings have two races.

The inner race is free to move while the outer race is fixed. When the bearing is in operation, it can provide very little friction but has a limited bearing capacity, due to the small area of ​​contact between the balls and the race.

#6 Roller Bearing

Roller Bearing
Image: IndiaMart.com

The roller bearings are intended to maintain accurate alignment of every part over a long period of time and can carry a heavy momentary load. This renders them suitable for machinery which required frequent starts and stops.

The rolling action of the bearings makes line contact with their races while the balls make point contact. It has a higher load-carrying capacity. This bearing includes cylindrical rolling elements instead of balls as load-carrying between races.

#7 Plain Bearing

Plain Bearing

Plain bearings are the simplest type of bearings, it usually consists of a bearing surface. There is no rolling element, so plain bearings are used for rotational, sliding, reciprocating, and oscillating motion.

The bearing remains stationary while the journal slides on the inner surface of the bearing. These bearings are basically a sleeve mounted on the shaft and fit into the bore. The plain bearings are cheaper, compact, and lightweight compared to other types. In addition, they can provide high load-carrying capacity.

#8 Linear Bearing

Linear Bearing

Linear bearings are like rolling components that decrease friction between moving systems where motion acts on a straight path. The linear bearings slide in a straight path because they are a bearing that allows a significant amount of weight to move with great ease in a linear motion.

Linear bearings can provide more precise speed control than other bearings with higher loads and rigidity. In addition, these bearings do not require lubrication or maintenance. They are suitable for a wide range of applications in packaging machinery and food processing equipment.

#9 Fluid Bearing

Fluid Bearing
Image: waukbearing.com

This is a special type of bearing, that relies on pressurized gas or liquid to carry the load and eliminate friction. Fluid bearings are used to replace metallic bearings where they would have a short life.

In addition to high noise and vibration levels, these bearings are used in machines that work at high speeds and loads. While the initial costs are higher the longer life span in tough conditions makes up for it to run longer time.

#10 Magnetic Bearing

Magnetic Bearing

Magnetic bearings employ the principle of magnetic levitation to keep the air in the center of the shaft because there is no physical contact. These bearings have zero-wear, also limiting the maximum amount of relative motion that it can handle.

In addition, Magnetic bearings provide some changes in shaft design because the position of the shaft is automatically set according to the center of mass. Magnetic bearings offer many advantages for various applications such as compressors, centrifuges, high-speed turbines, etc.

#11 Jewel Bearing

The jewel bearings are similar to plain bearings, in which a metal spindle is turned into a jewel-lined spindle hole. The hole is usually torus-shaped and slightly larger than the diameter of the shaft. These jewels are formed by mineral corundum either maybe synthetic sapphire or synthetic ruby.

Jewel bearings are employed in a variety of industrial applications and precision equipment where low friction, long life, and dimensional accuracy are essential. Jewel bearings are most commonly used in mechanical watches.

#12 Flexure Bearing

A flexure bearing is used to comply with one or more angular degrees of freedom. These bearings are often referred to as part of the compliance mechanism. They serve much of the same auction as conventional bearings or hinges in applications that require angular compliance.

However, flexures do not require lubrication and provide very little friction. Flexure bearings are found to be simple and inexpensive. They are often small, light in weight, and easy to repair with specialized tools.


Conclusion

So now, we hope that we have cleared all your doubts about Bearing. If you have still any doubts about the “Types of Bearings” you can contact us or ask in the comments.

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Image source:

The images are from VXBBearing.com, Timken.comnorfolkbearings.com

About Saif M

Saif M. is a Mechanical Engineer by profession. He completed his engineering studies in 2014 and is currently working in a large firm as Mechanical Engineer. He is also an author and editor at www.theengineerspost.com

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