Definition of Lubrication:
To supply lubricating oil between the moving parts is simply termed as lubrication.
Friction
is the force that resists relative motion between two bodies in contact. If
friction didn't exist nothing would ever stop moving for this reason
lubrication is necessary.
The function of lubricants is to reduce friction and heat.
Purpose of Lubrication:
- To
reduce the frictional forces between the parts having relative
motion
- To reduce
the wear and tear of moving parts
- Corrosion
prevention
- To cool
the surfaces by carrying away the heat generated due to friction
- To seal
a space adjoining the surfaces such as piston rings and cylinder
linear
- To absorb
the shocks
- Cleaning
agent
- To help
the piston rings to seal the gases inside the piston cylinder
- Increase fuel economy by providing low friction surfaces
Advantages of lubrication in the engine parts:
- Higher
efficiency
- longer life
- better
reliability
- less money spent on maintenance
Parts of Engine Requires Lubrication:
The
main parts of the engine which need lubrication are:
- Main
crankshaft bearings.
- Big end bearings or crank pin.
- Gudgeon in bearings.
- Piston
rings and cylindrical walls.
- Timing gears.
- Camshaft
and camshaft bearings.
- Valve
mechanism
- Valve
guide, valve tappets, rocker arms.
- Governor
and
- Water pump
bearing.
Any
substance introduced between two moving or sliding surface with a view to
reducing the frictional resistance between them is called lubricants.
Types of Lubricants :
Lubricants
are at following three types.
1.
Solid: graphic, mica etc
2.
Semi-solid: grease
3.
Liquid: mineral oil, vegetable oil, animal oil etc.
Graphite
is often mixed with oil to lubricate automobile spring. Graphite is also used
as a cylinder lubricant.
Grease
is used for chassis lubrication.
Mineral
oils are almost used for engine lubrication.
Grade
of lubricants: Generally, lubricating oils are graded by their SAE (society of automotive engineers)
viscosity number.
5w,10w,20w
SAE number lubricating oil are for winter use.
20,30,40
SAE number lubricating oil is for summer use.