What is torsion spring?

   Torsion springs are helical springs that produce torque or rotational force. Torsion spring ends are connected to other components, and when those components rotate around the spring's center, the spring tries to push them back to their original position. Torsion springs are subjected to bending stress rather than torsional stress, despite their name. By deflecting the legs about the body centerline axis, they can store and release angular energy or hold a mechanism in place statically.

Normally, this type of spring is close wound, but it can have a pitch to reduce friction between the coils. They provide resistance to twist or rotational force. Torsion springs can be designed to rotate clockwise or counterclockwise, depending on the application, determining the wind direction.

APPLICATION

    Torsion springs are frequently found in clothes pins, clipboards, swing-down tailgates, and garage doors. Hinges, counterbalances, and lever returns are examples of other application types. Miniature torsion springs are used in electronic devices, while large torsion springs are used in chair control units. Unwinding from the free position is not recommended; the load should be applied in the direction of the wind. Torsion springs shrink in diameter as they wind up, and their body length increases. When design space is limited, this should be taken into account. Torsion springs work best when they are supported by a rod, also known as a mandrel. When working with a torsion spring, the engineer or designer must consider the effects of friction and arm deflection on torque.

Relevant Torsion Spring Parameters

DIMENSIONS

    Inside Diameter, Outside Diameter, Wire Diameter, and Body Length are all measurements.

When the spring must slip over a mandrel with enough clearance to operate freely, the Inside Diameter is specified.

When the spring must fit into a circular hole with enough exterior clearance to operate freely, or when there are issues with outer housing clearance, the Outside Diameter is specified.

The Body Length is the length of the spring coil when it is relaxed.

PERFORMANCE FACTORS

Maximum Deflection, Maximum Load, and Wind Specifications

   The angular return torque provided per unit of angular displacement, such as inch-lbs per degree, is referred to as the spring rate.

Maximum Deflection is the spring's maximum rated angular deflection to overstress.

The rated load at the rated maximum deflection is referred to as the Maximum Load.

Torsion spring winds can be right hand, left hand, or double torsion. Lee Spring Stock Torsion Springs are available with equal-length legs oriented at varying unloaded angles.