Home > Blog > Common problem > How to determine the length of a constant force spring

How to determine the length of a constant force spring

source:Qianye Precision time:2022-9-14

  Constant force springs are mechanical devices used in applications that typically require some kind of balance or retraction mechanism. In design and function, constant force springs differ from the more common types of coil springs. They apply a consistent linear force or torque that remains constant over a wide range of motion.

When a coil spring is under force, whether it is stretched, compressed, or rotated, it produces a force proportional to its stretch. How a spring responds when a force is applied or released is called spring deflection. Years of experience tell us what happens when a spring is released from its temporary state. We know that the spring will return to its original position, but it will be proportional to the force exerted on it before releasing. A spring has a restoring force that allows the elastic material to return to its original state – the equilibrium position after the applied force is removed.

Stretching, squeezing or twisting, what makes a coil spring a spring is its proportional restoring force. It’s named after the 17th-century British physicist Robert Hooke who made the discovery, according to Hooke’s Law. Essentially, this law describes a linear relationship where the amount of stress applied to a spring is proportional to the force applied to it.

    Determine the length of the constant force spring
Constant force springs differ from traditional helical wound springs. First, they are made from high-volume, thin pre-stretched stainless steel strips that are coiled into flat spirals. In contrast, coil springs are not flat, thin steel strips, but are made of spring wire. The flat helical design of the constant force spring allows for a large angular deflection of multiple rotations, allowing only a small portion of the entire stretch to be used.
    Although classified as extension springs, the most common type of constant force spring is the helically wound torsion spring, which can be designed to produce a consistent force in linear motion or manufactured to apply a constant torque. A constant force spring does not have the same proportional restoring force as a spring governed by Hooke’s law. Instead of a proportional force, a spring exerts a consistent linear force over its range of motion.

    As the flattened strip unfolds, its energy is stored within the strip. When a force is required for linear motion, the strip extends along a linear path. If torque is needed to provide rotational motion, the strip can either coil itself or move in the opposite direction onto another spool. How designers and engineers need to determine the overall length of a constant force spring when working on a design project. The general rule states that once the full load rating of the spring extends to a length equal to 1.25 times its diameter, a near-constant force is developed. From then on, it maintains a relatively constant force regardless of the extension length. The load is determined by the width and thickness of the material and the diameter of the coil.

     Advantages of constant force springs
Springs are extremely durable, with fatigue life cycles ranging from 2,500 cycles to 1,000,000 cycles, depending on the size of the spring and the loads it is designed to support. They are found in mechanical devices with long motion capabilities. This will include counterweights, door closers and feed mechanisms for floor dispensers and automated machinery; also retractable hoses, cords, tool head returns, seat belts and exercise equipment; as well as hair dryers, toys, motors, appliances Wait. Constant force springs are versatile springs with a variety of applications where a constant load is required to balance, provide tension, retract or dispense objects.
    Shenzhen Qianye Precision Metal Co., Ltd. is a professional manufacturer of high-precision clockwork springs. The company integrates product development, production, sales and service, and has all kinds of skilled and experienced engineering and management personnel. Sincerely welcome new and old customers and friends from all walks of life to visit the company and negotiate business cooperation 13827443413 Liu Gong! Qianye Precision will serve you wholeheartedly!
Tags: , , ,

Latest News

 Scene principle of constant force spring
Scene principle of constant force spring

Time:2022-9-14

The constant force spring is made of stainless steel strip. The high-strength steel strip is shaped by specific spring production equipment. When it is straightened by external force, the spring will naturally roll back and produce elastic force. However, when our goal is achieved, it can return to the starting point specified by us after displacement. So do you know that constant...

 Application of spring in display
Application of spring in display

Time:2022-9-14

The diversification of modern life, people in the pursuit of high quality life at the same time also constantly in innovation. Leisure, shopping traditional products only meet material needs, people began to pursue diversified products. Let me feel deeper, such as display lifting design, this design to work and life has brought a lot of convenience. The reason why the...

 Variable Force Springs In New Point Of Purchase Display
Variable Force Springs In New Point Of Purchase Display

Time:2022-9-14

Automatic advance shelves are more widely used in stores and people's lives, and are more often used for displaying and placing goods (incense hata, rosemary, etc.). However, the conventional shelf propeller has one end of the baffle on both sides fixed and the other end movable. Although in use, after the first row of goods is taken away, the second...

 How long can the spring last?
How long can the spring last?

Time:2022-9-14

How long can stainless steel springs last? This is a common problem. You might think that as long as it's not stretched beyond the point of recovery, the spring will always return to its original shape. A spring is a mechanical part that uses elasticity to work. Parts made of elastic materials deform under the action of external force, and...

 Application of constant torque spring in 3D printer
Application of constant torque spring in 3D printer

Time:2022-9-14

3D printing, also known as three-dimensional printing, is a kind of rapid prototyping technology. It uses adhesive materials such as powdered metal or plastic to construct zero objects through multi-layer printing layer by layer. Mold making, industrial design is used to build models, and is now developing into product manufacturing, forming "direct digital manufacturing". Some high-value applications (such as hips...

 Brush spring protector
Brush spring protector

Time:2022-9-22

       Conventional motor arrangements include a rotor with windings to conduct current during machine operation. As the rotor rotates, current is conducted through the rotating elements from sources external to the rotor to the rotor windings. A rotating element such as a slip ring or a commutator contacts the brush spring to conduct current.        There...

Product