BEARING INTRODUCTION-TYPES-BEARING MATERIAL AND BEARING IMAGE-FITTER ONLINE NOTE.

INTRODUCTION:-

1- To keep the long shaft or moving parts of the machines in proper position by the supporting devices are called bearing.

2- Bearings form part of an assembly or mechanism which supports or constrains another part in the assembly.

A bearing material should have the following properties:

 a)- Offer the least possible resistance to motion.

b)- Have good wear resistance.

c)- Be able to absorb sudden loads.

d)- Be able to conduct heat away from the bearing surface .

e)- Resist corrosive conditions .

f)- It should consume less energy on moving at high speed.

Bearing Metal:-

i)- For low speed and heavy lode - Cast iron.

ii)- For high speed and Heavy lode - Bronze.

iii)- Shell Bearing - White metal or Babita metal.

iv)- In addition to that Cadmium Steel, Chromium Steel,Copper,Aluminium and Silver and alloy steel bearing are also made.

Bearings are used:-

i)- support and hold the shaft in a fixed position.

ii)- allow the shaft to run freely.

iii)- restrain moving elements.

iv)- minimize the rubbing action.

Types Of Bearing:-

Generally bearing are two types a)-Plain bearings, b)-Anti-friction bearings.

a)-Plain bearings:- 

i)- Its depending on the direction of load application.

ii)- Plain bearings operate on the principle of sliding friction

ii)- They are two types  Radial or journal bearings and Thrust bearings.

Radial or journal bearing:- In this, the loading is at right angles to the bearing axis. 

Thrust bearings:- In this, the loading is parallel to the bearing axis.

Radial or journal bearing

Characteristics of plain bearings:- These bearings have a cylindrical shape and are fitted in a housing.

Types of plain bearing:- i)- Solid bearing, ii)- Split bearings, iii)- Self-aligning bush bearings, iv)- Adjustable slide bearing .

Types of plain bearing

i)- Solid bearing:-

i)- These are made in the form of bush made of bearing material.

ii)- It is press fitted in cast iron or fabricated housing.

ii)- Split bearing:- 

i)- These bearings are made in two halves

ii)- which are assembled in special plumber blocks.

Split bearing

iii)- Self-aligning bush bearings:-

i)- The bearing bush is press fitted into a special sleeve for felf-aligning.

ii)- which self-align slight angular misalignment or deflection.

iv)- Adjustable slide bearing:- 

i)- This type of bearing has provision for wear adjustment. 

ii)- The bearing is fitted in the tapered hole of the housing for adjustment of wear. 

iii)- The bearing is drawn inside by means of a nut.

b)-Anti-friction bearings.

i)- In this type of bearing there is no friction because it has rolling contact.

ii)- In this bearings in place of friction balls are fitted on it.

iii)- due to this reason speed increases and friction and temperature decreases. such bearing has long life.

Advantages of Anti-friction bearings

i)- It has very less friction in it.

ii)- It has very long life.

iii)- It is easy to replace.

iv)- Required less lubrication.

v)- It is easily operates on high speed.

vi)- Special shielded bearing does not require lubrication again.

Types of Anti-friction bearings:-

a)- Ball bearing, b)- Roller Bearing, c)- Spherical Bearing.

a)- Ball bearing:- 

i)- These bearings are most widely used of all the bearings.

ii)- These bearings is consists of this parts a)- Inner Race, b)- Outer Race, c)- Cage, d)- Ball.

iii)- Ball bearings are two types a)- Single Row Ball Bearing, and b)- Double Row Ball Bearing.

a)- Single Row Ball Bearing:- Those bearings have only one groove cut in outer and inner rings with ball in one line that bearing is called Single Row Ball Bearing.

b)- Double Row Ball Bearing:- Those bearing has two grooves cut in inner and outer rings and having balls on both the rows that is called Double Row Ball Bearing.

 b)- Roller Bearing:-

i)- These bearings have grooved races in which rollers are used as rolling element.

ii)- these are suitable for high speed with heavy lode.

iii)- There are four types of roller bearings 1)- Cylindrical Roller Bearing, 2)-Barrel Roller Bearing, 3)- Needle Roller Bearing, 4)- Taper Roller Bearing.

 1)- Cylindrical Roller Bearing:- 

i)- These bearing are used in such place where more lode is to be required.

ii)- These are made of hollow cylindrical roller.

2)-Barrel Roller Bearing:- 

i)- The roller fitted in this type of bearing has barrel shape.

ii)- Its deameter upto full length is uneven.

iii)- These bearings are self alignment types bearing.

iv)- It has no difficulty to maintain shaft in straight line.

3)- Needle Roller Bearing:- 

i)- This type of bearings are thin like roller needle.

ii)- These are used for plase required high speed and more accuracy.

4)- Taper Roller Bearing:- 

i)- This type of bearing roller are in taper having more diameter at one end and less diameter on second end.

ii)- These bearings are used for heavy works and high speed.

iii)- These are mostly used in automobile section.

c)- Spherical Bearing:-

i)- A spherical roller bearing is a rolling-element bearing that permits rotation with low friction, and permits angular misalignment.

ii)- The rolling elements of spherical roller bearings are mainly cylindrical in shape