A tension spring is a helical spring that stores energy by axial stretching and deformation. It usually has hooks or threaded structures at both ends to transmit tension.
A torsion spring is a spiral spring that stores energy by twisting around its axis. It usually has fixed arms or hooks at both ends to transmit torque.
The canted coil spring is a spring whose spiral axis is at a specific angle to the load direction, and realizes compound load support (axial compression + radial torsion) through multi-directional elastic deformation.
The difference between special-shaped springs and regular springs is that the springs themselves are irregular, with bends and a large number of complex angle designs
