Constant force spring is also known as (roll) spring. The spring is a kind of spring that makes the material spiral in a plane. One end of the spring is fixed, and the other end acts on the torque. The material is subjected to bending moment and produces bending elastic deformation. Therefore, the spring produces torsion on its own plane. Its deformation angle is directly proportional to the torque. It has high torque and multi angle torsion force distance. Therefore, it is not easy to fatigue when it is applied to a mechanism that works for a long time. Its use is similar to that of a torsion spring.
The flat steel strips of 55si2mn, 60Si2MnA, 55SiMnVB, 55simnmov, 60crmn, 60crmnb, 302, 316 and other brands of flat steel are generally selected for the spring.
The application categories include clocks and clocks, recording instruments, motor toys, tape measure, automobile starting motor, storage wire box, etc.
The planar scroll spring is classified according to whether it contacts with adjacent working parts: ① non-contact planar scroll spring; ② contact planar scroll spring. The fixation methods of the fixed end of the plane scroll spring are: ① hinged fixation, ② pin fixation, ③ V-shaped fixation, and ④ lining fixation.