Short Answer:
The function of a helical torsion spring is to store and release rotational (twisting) energy. It works by resisting twisting motion and applying a torque in the opposite direction when it is rotated. This type of spring is made from a helical coil and has legs or arms that apply or receive torque.
Helical torsion springs are commonly used in cloth clips, door hinges, car hoods, mouse traps, and mechanical watches. They help in rotating parts back to their original position and provide controlled motion in machines and tools.
Detailed Explanation:
Function of a helical torsion spring
A helical torsion spring is a special type of spring that works by twisting rather than stretching or compressing. When its arms or legs are rotated around the spring’s center axis, the spring twists and stores energy. Once the load is removed, it releases the stored energy and returns to its original shape, thus applying a torque.
These springs are widely used in mechanical systems where a rotational force or return motion is needed.
Working principle of helical torsion spring
Unlike compression or extension springs, which work in straight-line motion, a helical torsion spring works in angular motion. It produces torque and rotational energy when one arm of the spring is pushed or pulled, causing the coil to wind or unwind.
How it works:
- The spring is mounted on a shaft or rod.
- One leg of the spring is fixed, and the other is pushed or rotated.
- This causes the coils to twist, storing energy in the spring.
- When the force is released, the spring tries to return to its original position, generating torque.
Key features of helical torsion spring
- Helical shape made by winding wire in a spiral
- Works by twisting motion (torque)
- Has arms or legs that apply or resist rotational force
- Returns to starting position after load is removed
- Available in both clockwise and counter-clockwise windings
Main functions of helical torsion springs
- Store rotational energy
- It absorbs energy when twisted and releases it when the load is removed.
- Provide torque
- It applies a twisting force to rotate or hold parts in position.
- Control angular movement
- Helps in opening, closing, or controlling motion smoothly.
- Restore original position
- Returns components to their neutral position after motion, like a door hinge or mouse trap.
Applications of helical torsion springs
- Cloth clips – applies pressure to hold clothes using torsion force
- Car hoods or trunk lids – helps in smooth lifting and holding open
- Garage doors – balances door weight during opening/closing
- Hinges of doors – allows auto return of the door after opening
- Mechanical watches – used in winding mechanisms
- Toys and wind-up devices – stores and releases energy for motion
These springs are also used in:
- Sewing machines
- Electrical switches
- Agricultural equipment
- Industrial tools
Factors affecting spring performance
- Material – Steel is most common; stainless or coated steel for corrosion resistance
- Wire diameter and coil diameter – Affect torque capacity
- Number of coils – More coils = more flexibility, less torque
- Arm length and angle – Affects how and where the torque is applied
Proper design ensures that the spring delivers the right amount of torque without getting damaged or losing strength.
Conclusion
The function of a helical torsion spring is to produce rotational force (torque) and control angular motion in mechanical systems. It stores energy when twisted and releases it to return parts to their original position. These springs are essential in devices like clips, hinges, door systems, and mechanical toys, offering simple yet reliable motion control. Their ability to rotate parts smoothly and repeatedly makes them an important part of many machines.