This document summarizes key information about helical springs including their application, classification, design considerations, and equations. Helical springs are elastic devices that store energy and can be used to apply or absorb force. They are classified further into compression and tension types. The design of helical springs considers factors like torsional shear stress, direct shear stress, angular deflection, deflection, stiffness, and maximum shear stress which are defined through mathematical equations in the document.

1. Helical spring
L. J. POLYTECHNIC, AHMEDABAD
SUBMITTED BY:
1. Vatsal thakkar (166330319614)
2. Kamlesh sonkusare (166330319611)
Mechanical Engineering Department
Design of machine element (DME)

2. What is spring?
• Spring is a device used to store energy, so that
when the energy is needed, it is released
• It is defined as elastic bodies.

3. Application of spring:
• To apply the force
• To absorb the shock
• To measure the force
• To store the energy
• To control the force

4. Classification of spring:
spring
Helical spring
Compression
helical spring
Tension helical
spring
Leaf spring Disc spring
Torsion spring
Conical spring

5. Helical spring

6. Design of spring :
• Torsional shear stress:
𝑇1 =
8𝑊𝐷
𝜋𝑑3
Direct shear stress:
𝑇2 =
4𝑤
𝜋𝑑2
Shear stress factor
𝐾𝑠 = 1 +
1
2𝑐

7. • Angular deflection of wire
𝜃 =
16𝑛𝑤𝐷2
𝐺𝑑4
• Deflection of spring
𝛿 =
8𝑛𝑤𝐷3
𝐺𝑑4
• Stiffness:
𝑘 =
𝐺𝑑4
8𝑛𝐷3
𝑇 𝑚𝑎𝑥 =
𝑘8𝑊𝐷
𝜋𝑑3

8. •THANK YOU