Short Answer:

The types of springs are mainly classified according to their shape, mode of loading, and application. The most common types include helical springs, leaf springs, torsion springs, spiral springs, and disc (Belleville) springs. Each type of spring is designed to perform a specific function such as absorbing shock, storing energy, or applying a force.

In simple words, springs can be of various shapes and functions. Some are used for compression, others for tension or twisting. The most widely used types are compression springs, tension springs, torsion springs, leaf springs, and spiral springs, which are commonly found in vehicles, machines, and measuring instruments.

Types of Springs

Detailed Explanation :

Springs are elastic mechanical elements that store and release energy when a force is applied and removed. Depending on their design, application, and type of loading, springs are classified into several types. Each type has unique properties and is used in specific engineering situations to achieve desired motion, cushioning, or force control. Understanding the types of springs is essential in mechanical engineering for designing efficient and reliable systems.

1. Helical Springs

Helical springs are the most common and widely used springs. They are made by winding a wire in the form of a helix and are designed to resist axial forces. Depending on the direction of loading, helical springs are divided into three main types:

1. a) Compression Spring:

• A compression spring is used to resist compressive loads.
• It shortens when an external force is applied and returns to its original length when the load is removed.
• Commonly used in vehicle suspension systems, ballpoint pens, and shock absorbers.

1. b) Tension (Extension) Spring:

• A tension spring is designed to resist pulling or stretching forces.
• It extends when loaded and returns to its original shape when the force is released.
• It usually has hooks or loops at its ends for attachment.
• Found in trampolines, garage doors, and weighing machines.

1. c) Torsion Spring:

• A torsion spring works under twisting or torsional load.
• When twisted, it stores energy and exerts a torque in the opposite direction.
• Common examples include cloth clips, door hinges, and safety pins.

The equation for deflection in a helical spring is based on Hooke’s Law, where the spring constant (k) defines its stiffness.

2. Leaf Springs

Leaf springs consist of several flat plates (leaves) of different lengths, placed one over another and clamped together at the center. They are mainly used to support heavy loads and absorb shocks in vehicles such as trucks, buses, and railway carriages.

Features:

• The longest plate is called the master leaf, and the rest are called graduated leaves.
• When the load is applied, the plates bend, absorbing energy and reducing shocks.
• The plates slide over each other, which provides flexibility and strength.

Leaf springs are simple in design, strong, and durable. They can bear large bending stresses and are preferred for heavy-duty applications.

3. Spiral Springs

A spiral spring (also known as a clock spring or flat spiral spring) is made of a flat strip of metal wound in the form of a spiral. It works under torsional stress and stores energy when wound.

Features:

• The energy is released when the spring unwinds.
• Commonly used in watches, mechanical timers, measuring tapes, and clocks.
• They are compact and can store a considerable amount of energy in a small space.

Spiral springs are often made of thin, high-strength materials like spring steel to achieve flexibility and long life.

4. Disc or Belleville Springs

A disc spring, also known as a Belleville spring, is a conical-shaped disc that deflects axially when loaded.

Features:

• It provides high load capacity with a very small deflection.
• Used in clutches, brakes, and heavy machinery.
• Offers compact design and high energy absorption capability.
• Multiple disc springs can be stacked to increase load-carrying capacity or flexibility.

Disc springs are particularly useful where space is limited but high force is required.

5. Volute Springs

Volute springs are coiled in the form of a cone or spiral, with each coil fitting inside the next. When compressed, the coils slide over each other, giving a short solid length.

Features:

• Stronger than ordinary helical springs.
• Can absorb large shocks and carry heavy loads.
• Commonly used in heavy-duty applications such as railway buffers and defense equipment.

6. Torsion Bar Springs

A torsion bar spring is a straight bar that resists twisting when subjected to torque. The bar stores energy in the form of torsional stress.

Features:

• Works by twisting about its longitudinal axis.
• Found in vehicle suspensions and aircraft landing gears.
• Provides smooth motion and excellent fatigue resistance.

Torsion bars are simple and durable and can replace coil or leaf springs in certain suspension systems.

7. Air and Hydraulic Springs

In modern systems, air springs and hydraulic springs are also used to absorb vibrations and shocks.

Air Springs:

• Use compressed air in a flexible rubber bellows to provide cushioning.
• Used in vehicle suspensions for comfort and adjustable stiffness.

Hydraulic Springs:

• Use fluid pressure and piston-cylinder arrangement to absorb shock.
• Used in dampers, shock absorbers, and vibration isolators.

These types of springs offer adjustable stiffness and excellent damping performance.

Applications of Different Springs

• Helical springs: Used in vehicles, valves, and machinery.
• Leaf springs: Used in trucks, cars, and railway bogies.
• Spiral springs: Used in clocks, watches, and measuring tapes.
• Disc springs: Used in clutches, braking systems, and mechanical presses.
• Torsion bars: Used in automobiles and aircraft suspensions.

Conclusion

In conclusion, springs are versatile mechanical elements designed to store energy, absorb shock, and provide controlled motion. The main types of springs include helical, leaf, spiral, disc, and torsion bar springs, each serving specific functions in engineering systems. The selection of a spring type depends on the nature of load, space availability, and required stiffness. Springs play a vital role in mechanical systems ranging from simple household tools to advanced automobile suspensions and precision instruments.