PPT On Spring Design , it is used in Machine Design for Engineering and At various Perpuses. Compression springs are coil springs that resist a compressive force applied axially. Compression springs or coil springs have a spring constant and may be cylindrical springs, conical springs, tapered , concave or convex in shape. Compression springs are linear and thus have the same rate per inch throughout the entire spring. You can have large compression springs, heavy duty compression springs, conical compression spring, small compression springs, or even micro compression springs. Coil compression springs are wound in a helix usually out of round wire. The changing of compression spring ends, direction of the helix, material, and finish all allow a compression spring to meet a wide variety of special industrial needs. Coil springs can be manufactured to very tight tolerances, this allows the coil spring to precisely fit in a hole or around a shaft. A digital load tester, or coil spring compression tester can be used to accurately measure the specific load points in your metal spring. The possibilities are almost endless because there are so many applications for metal springs. Compression springs can accomplish many types of applications such as pushing or twisting, thus allowing you to achieve numerous results. Compression springs offer resistance to linear compressing forces (push) and are in fact one of the most efficient energy storage devices available. A ballpoint pen is an excellent example of how small compression springs work. The small spring will compress when the pen is clicked and then the small spring will return to it's original position. Other uses include vibration dampening and high temperature applications. Compression springs that are engineered for high temperature applications can reach up to 1,100 degrees Fahrenheit.

1. Design of Springs

2. Definition of spring
• A spring is an elastic object used to store mechanical energy. Springs are elastic
bodies (generally metal) that can be twisted, pulled, or stretched by some force. They
can return to their original shape when the force is released. In other words it is also
termed as a resilient member.

3. Objectives of Spring
• 1. Cushioning , absorbing , or controlling of energy due to shock and vibration. Car
springs or railway buffers to control energy, springs-supports and vibration dampers.

4. 2. Control of motion
Maintaining contact between two elements (cam and its follower)In a cam and a follower
arrangement, widely used in numerous applications, a spring maintains contact between the
two elements. It primarily controls the motion. Creation of the necessary pressure in a friction
device (a brake or a clutch)A person driving a car uses a brake or a clutch for controlling the
car motion. A spring system keep the brake in disengaged position until applied to stop the
car. The clutch has also got a spring system (single springs or multiple springs) which
engages and disengages the engine with the transmission system . Restoration of a machine
part to its normal position when the applied force is withdrawn (a governor or valve)A typical
example is a governor for turbine speed control. A governor system uses a spring controlled
valve to regulate flow of fluid through the turbine, thereby controlling the turbine speed.

5. • 3. Measuring forces Spring balances, gages.
• 4. Storing of energy In clocks or starters The clock has spiral type of spring which is
wound to coil and then the stored energy helps gradual recoil of the spring when in
operation. Nowadays we do not find much use of the winding clocks.

6. Applications Of Spring
• In Suspension , Compression Helical Springs are Used
• When a Compression force is applied their length reduces andThey operate
in Compression load
• Helical Extension Spring in Spring balance with Extended hook placed
vertically , also inWeighing Machine

7. Helical Compression Spring
• It is also known as Coil Spring.
• Compression Springs are open-coil helical springs wound or
constructed to oppose compression along the axis of wind.
Helical Compression is the most common metal spring configuration.
These coil springs can work independently, though often assembled
over a guide rod or fitted inside a hole.

8. Helical Compression spring
• Made from round wire and wrapped in Made from round wire and wrapped
in cylindrical form with a fixed pitch.
• Plain end - Least expensive,Tends to bow sideways under load
• Plain and ground end - Better mating conditions being flat, Likely to get
entangled in storage
• Squared end
• Squared and ground end

9. • Helical Compression Springs are used in multiple applications . It is mainly
used for energy storage in Suspension ofAutomobile .
• It is observed that the axial force applied on the helical spring do not
transfer completely at other end .

10. Types of compression springs

11. Helical Extension springs
• Similar to compression springs .
• Manufactured with each winding touching the Manufactured with each
winding touching the adjacent winding with a preset residual load .

12. Helical Extension springsTypes of end hooks

13. Calculation of Force
To Calculate force we need to Measure some things like :-
• Measure Spring wire diameter using calipers
• Measure outside diameter of coil
• Length in free condition (Uncompressed)
• Count the number of coils
• Also theWinding Direction of coil

14. Uses in Automobiles
• It is used in FrontWheel Drive (FWD) Cars .
• Used to support the rear dead axle in rear suspensions .
• Eg:- 1) Kia Seltos
2) Maruti Suzuki Swift
3)Tata Altroz

15. Spring Rate
• Spring rate (k) is ratio of change in force to the Spring rate (k) is ratio of
change in force to the change in length .
• Force (F) exerted by the spring is F = k (Lf – Lo)

16. Spring index
• Ratio of mean diameter of a spring to the wire from Ratio of mean diameter
of a spring to the wire from which the spring is constructed
• Spring index, C

17. Pitch
• Number of coils per Number of coils per inch of length

18. Allowable stress
• Allowable stress
• Q = expected ultimate strength of a 1 inch bar inch bar
• x = factor
• LF = loading factor LF = loading factor

19. Spring Stresses
• Torsional shear stress
• A = wire cross sectional area
• c = radius of wire cross section
• J = polar moment of inertia
• D = diameter of wire

20. Spring Stresses
• Torsional shear stress
• Peak stress is more because of the curvature Peak stress is more because of
the curvature effect

21. Spring Stresses
• Spring sizing is based on

22. We will take Maruti Suzuki Swift
Max Power :- 89 bhp and 6000 rpm
MaxTorque :- 113 Nm and 4400 rpm
Engine :- 1198 cc

23. Conclusions
• Springs produce a large deflection and used for a Springs produce a large
deflection and used for a number of applications.
• Most springs are made of steel.
• Stress and deflection in coil springs was derived.
• Springs can be connected in series and parallel.
• There are a number of other spring configurationsThere are a number of
other spring configurations used in engineering.