Constant-force springs are a special variety of extension spring. They consist of a spiral of strip material with built-in curvature so that each turn of the strip wraps tightly on its inner neighbor. When the strip is extended (deflected) the inherent stress resists the loading force, just as in a common extension spring, but at a nearly constant (zero) rate. The accompanying load/deflection curves illustrate this.
The constant-force spring is will suited to long extensions with no load build-up. In use, the spring is usually mounted with the ID tightly wrapped on a drum and the free end attached to the loading force, such as in a counterbalance application. This relationship can be reversed, however, with the free end mounted stationary and the spring itself providing the working force, as with carbon brushes in electrical apparatus.
Considerable flexibility is possible with constant-force springs because the load capacity can be multiplied by using two or more strips in tandem, or back-to-back, as illustrated.
Type 301 or 1Cr18Ni9Ti stainless steel.
Note: Be sure to allow at least 1 1/2 coils of material on the drum at full extension. The spring ID will wrap tightly on the drum so that in most applications no fastening method on the drum is required.
|Forming method||Spring Elastic N||Spring width||Spring thickness||Outside diameter||Number of turns||Note|
|Cold roll willow||5.9||12||0.12||10.5||>4.5|
|Note: In addition to the above specifications, if the customer has special requirements, the company can design and manufacture.|
|product material||Spring Material: 2 Crl 9 Ni 9 M Material: lCrl 8 Ni 9 / Weave Material: T 3/304|
|1. Operating temperature: -401 C ~ 1401 C ;|
|skills requirement||2. In the constant force area of the spring, the elastic attenuation does not exceed 2%;|
|3. The springs should be kept bright after being shaped, and there must be no cracks, stings or folds.|
|main application||Constant force type brush box / railway / car / electromechanical / mining and other fields|