[attachment=3549]

NITRO SHOCK ABSORBERS THE ULTIMATE IN PERFORMANCE AND COMFORT

---

Prepared by; ADITYA RAJ

---

CONTENTS
NEED FOR SHOCK ABSORBERS
WHY GAS FILLED SHOCK ABSORBERS
TYPES & ADVANTAGES
MOUNTING TIPS



NEED FOR SHOCK ABSORBERS
Springs alone cannot provide a
satisfactorily smooth ride.
Oscillation of spring causes the wheel to
rebound, or bounce up and down.
Control over the vehicle can be lost.
Shock absorbers prevent these spring
oscillations.




HOW IT WORKS
All shock absorbers use hydraulic fluid to convert the energy of the spring to heat.
Consists of two strokes
1. Compression &
2. Rebound




INSIDE OF A SHOCK ABSORBER
WHY GAS FILLED SHOCKS
Rapid movement of the fluid between the chambers cause foaming.
Results in a lag because the piston moves through an air pocket which offers resistance.
Foaming results in a decrease of damping and a loss of spring control.
Pressure increases in front of the piston and drops behind it.
All together results in foaming and loss of shock absorber control.



GAS FILLED SHOCKS
Designed to reduce foaming of the oil.
Construction is similar except the double tube, here a dividing piston is used.
Two chambers “ oil & gas.




COMPONENTS
Upper and lower mounts.
Hydraulic chamber containing hydraulic fluid.
Gas chamber containing nitrogen at
25 bars.
Dividing piston.
How it works
The piston rod is moved into the shock
absorber which displaces the oil.
This causes the dividing piston to press on the gas chamber, reducing it in size.
While returning the gas pressure returns the dividing piston to its initial position.
The pressure decrease behind the working piston cannot be high for the gas to exit from the oil column.
Thus the gas filled shock absorber operates without foaming.




TYPES AND DETAILS
There are two types of gas filled shock absorbers-
1. Mono tube with high pressure
2. Twin tube with low pressure
INSIDE OF A MONO TUBE
MONO TUBE




COMPONENTS:
1. Cylinder also called housing.
2. Piston connected to a piston rod.
3. Floating piston also called separating piston.
4. Piston rod guide.
5. Upper and lower attachment.



WORKING
The cylinder is not completely filled with
oil; the lower part contains nitrogen at
25-30 bar.
Gas and oil are separated by floating
piston.




BUMP STROKE
When the piston rod is pushed in the
floating piston is also forced down slightly
increasing pressure in both section.
Also the oil below the piston is forced to
flow through the piston, this generates
the bump damping.





REBOUND STROKE
When the piston rod is pulled out, the oil between piston and guide is forced to flow through the piston.
This resistance generates rebound damping.
At the same time part of piston rod will emerge from cylinder and free piston move upwards.
INSIDE OF A TWIN TUBE
TWIN TUBE


COMPONENTS:
1. Outer tube also called reservoir tube.
2. Inner tube also called cylinder.
3. Piston connected to a piston rod.
4. Bottom valve also called foot valve.
5. Piston rod guide.
6. Upper and lower attachment.



BUMP STROKE
When the piston is pushed in, oil flows to
the enlarged volume above the piston.
Simultaneously a quantity of oil is also
forced to the reservoir tube.



REBOUND STROKE
When the piston is pulled out, the oil
above the piston is pressurized and flow
through the piston.
Some oil flows back from the reservoir
tube to the lower part.




ADVANTAGES
Instantaneous response.
Better fade resistance.
Better durability.
No need for re-adjustment.




TIPS BEFORE MOUNTING
Avoid stiff suspensions.
Avoid new shocks to compensate for
old and tired springs.
Worn shocks reduce safety and
handling.
The best advice come from a mechanic
who knows your vehicle.


REFERENCES
In For A Shock , S.B.L Beohar
Automotive Encyclopedia; Tobolt.
Auto Mechanical Fundamental; Stockel.
http://belltech.net
http://monroeshocks.com
http://seminarsprojects.in

THANK YOU