IJAER, International Journal of Applied Engineering Research ... https://www.ripublication.com/Volume/ijaerv9n8spl.htm

1. SMOOTHNESS OF RUNNING
OF TRAIN ON UNEVEN
TRACKS WITH THE HELP OF
AIR SPRINGS

2. Suraj Kumar1, Dhananjay
Chauhan2,Jinesh jain3
1Department of Mechanical
Engineering, Bhagwant University,
Ajmer
2,3Department of Mechanical
Engineering, G.C.E, Ajmer
1Email:-gmpsuraj@gmail.com
2Email:-dcmechengg@gmail.com

3. ABSTRACT
The main purpose of the air spring is to restrict the vibration at
a desirable level as per requirements. Higher rail vehicle
speeds generally results in increased vibrations in the car body,
which has a negative impact on ride comfort. The suspension
of the vehicle has to be modified in order to reduce the
vibration and journey should be comfortable i.e. Jerk free
journey. It is always desirable to keep the vibration level as
low as possible by introducing damping.

4. ABSTRACT
The main purpose of the air spring is to restrict the vibration at a
desirable because with increased the speed, dynamic performance of the
vehicles is negatively affected. The trend towards higher rail vehicle
speeds generally results in increased vibrations in the car body, which
has a negative impact on ride comfort .The suspension of the vehicle has
to be modified in order to compensate vibration as well as work life
should have long i.e. maintenance cost is too low. In fact, most helical
spring possess low inherent damping thereby causing serious problems
which will impair the function and life of structures leading to their
ultimate failure as distortion which have bad impacts on economical
condition but air spring have more life as and as well as also reduce the
vibration as per desired level

5. Objectives of Air spring
a) Improve passenger ride comfort, b) Maintain good ride
comfort although vehicle speed is increased, c) Maintain good
ride comfort although track conditions are worse, d) Reduce
wheel and rail wear by means of improved curve negotiation,
e) Secure running stability at higher vehicle speed.

6. Working principle of pneumatic suspension
Air suspension is a suspension where properties of air are used
for cushioning effect (springiness). Enclosed pressurized air in
a pre-defined chamber called air spring, made up of Rubber
bellow & emergency rubber spring, provides various
suspension characteristics including damping. Air springs are
height-controlled load leveling suspension devices. With
changing loads, air spring reacts initially by changing the
distance between air spring support and vehicle body. The
height monitoring valve is in turn actuated, either taking the
Compressed air pressure to the air spring or releasing air
pressure from it to the atmosphere. This Process continues
until the original height is restored.).

7. Curve negotiation
When negotiate a curve at an excessive speed, vehicles will
roll over and automobiles will lose traction and slake out of a
curve instead of rolling over. The more top-heavy a vehicle is,
the more likely it will roll over than slake out of a curve. If the
ride comfort is already good, further improvement at
unchanged vehicle speed and track conditions is generally not
justified due to the high costs of implementing active
suspension. However, goals b) and e) allow large possibilities
for cost-efficient improvements.

10. Characteristics features of air suspension
• Soft flexible characteristics in vertical direction - Achieved
by compression of air. • Excellent lateral spring characteristics,
as desired. - Achieved by variation in effective area in lateral
direction.• Avoids excess air consumption due to instantaneous
modes of vehicle oscillation or change in air pressure-
Achieved by designing delayed reaction leveling.

12. Characteristics of spring materials

13. Load in KN(static) Vertical stiffness Cz In N/mm
Additional Volume 20 dm3 Additional volume 40dm3
50 600±100 N/mm 550±100N/mm
165 1200±200/mm 1000±200N/mm
180 1350±200N/mm 1150±200N/mm

14. Lateral spring stiffness of air spring assembly
Load in KN(static) Lateral stiffness Cy In N/mm
50 250±50N/mm
165 450±100N/mm
180 500±100N/mm

15. Space Constrains
i) Installed height without spigot =255+5 +0 mm ii) Maximum
permissible diameter of air spring =Ø740mm. iii) Maximum
permissible external diameter of to plate of air spring
=Ø750mm iv) Min, height of air spring under full load with no
air without spigot =215 mm
A. Pneumatic supply connection
Air inlet connection point to be air spring shall be located at the
centre of top plate through a spigot shall be as under:
i) Outer diameter=Ø85-0.036
-0.071mm ii)Height=35±0.5 mm iii)
Diameter of “O” ring =5.7±0.1mm

16. S.No. Characteristic Tolerance
1 Pressure force Characteristic ±5%
2 Load deflection Characteristic ±10%
3 Stiffness under sinusoidal ±15%

17. VIBRATION MEASUREMENT
. These factors can be summarized as:
(1) Ground quality (which is the most important factor) (2) Train type
(3) Railway track and the embankment design (4) Train speed (5)
Distance from the rail way track to the building (receiver) (6) Building
type and the foundation design
a. The general prediction formula
The following equation describes prediction of ground vibration from
railways,
V= VT* FD* FS* FR* FB (Where V = the vibration velocity [mm/s].)
VT = train vibration level perpendicular on the ground (Z direction) at a
reference distance Do, from the centre of the railway track and the
reference speed So [m/s].FS is a function of the train speed. FS=(S/So)A
where S is the train speed and S0 is the reference speed at which VT has
been measured. A can be between 0.5 – 1.5, we will later use A = 0.9.
FD is a function of the distance, which could be obtained by, FD=
(D/Do)B

19. TEST FOR EMERGENCY SPRING: LOAD V/S DEFLECTION TESTS
(During endurance test) Spring type: - H. capacity 180

20. CONCLUSION
In the previous days, helical spring is used to design and demonstrate the
wheel monitoring system in train. The helical spring less reduce the
vibration at most for current researches. The current researches scenario
the continuity improved the quality and safety purpose and it announce
new theme i.e. air spring suspension system. The air spring suspension
reduces the sudden failure rate and it is more comfortable in compare to
helical spring. And one of best thing with this spring is, it have
emergency spring which keeps it safe after any problem.

21. LITERATURE REVIEW
A. Helical springs
The helical springs are made up of a wire coiled in
the form of a helix and The cross-section of the wire
from which the spring is made may be circular,
square or rectangular and the helix angle is very
small, usually less than 10°.

24. WORKING PRINCIPLE OF PNEUMATIC SUSPENSION
it enclosed pressurized air in a pre-defined chamber
called air spring, made up of rubber bellow &
emergency rubber spring, provides various suspension
characteristics including damping. air springs are
height-controlled load leveling suspension devices.
with changing loads, air spring reacts initially by
changing the distance between air spring support and
vehicle body. the air springs replace only the
secondary suspension, whereas primary suspension
continues to use steel coil springs.

26. S.No Pressure in kg/cm2 Specific load in KN O observed load in KN
1. 1 kg/cm2 30.4 to 33.60 KN 31.25 KN
Lot size upto 10 25 50 75 100
No of samples 2 3 4 5 6
S.NO Item Firm’s RDSO approved Drg.No.
1 Top plate 750 mm
CHARACTERISTICS TESTS
Air Bellow: Table no1characteristics tests
Table no2 specified inspections
Table 3 check list for inspection of air spring

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