①Control the movement of machinery, such as internal combustion engines in the valve springs, clutch control springs.
② absorb vibration and shock energy, such as automobiles, train cars under the buffer springs, couplings in the vibration-absorbing springs.
③Store and output energy as power, such as clock springs, firearms in the spring.
4 as a force measuring element, such as force gauge, spring scale in the spring. Spring load and deformation ratio is called spring stiffness, the greater the stiffness, the stiffer the spring.