M- mass of the object acting on the spring (kg)
Ms- spring mass (kg) N- variable load cycle number
N- spring working circle
Nz- spring support ring number
N1- total number of turns of the spring
P'- Spring single ring stiffness (N/mm)
R- The middle radius of the coil (mm)
R1- inner radius of the coil (mm)
R2- outer radius of the coil (mm)
R- damping coefficient
S- safety factor
T-torque; torque (Nmm)
T'- torsional stiffness (N-mm /(0))
T- spring moment
Tc- cable pitch (mm)
U- deformation energy (N: mm); (N: mm-rad)
V-spring volume (mm3)
V- Impact body speed (mm/s)
Zm- bending section coefficient (mm3)
Zt- torsional section coefficient (mm3)
A- helix angle (°); coefficient
-- wire rope angle (°); cone half angle (°); coefficient
Δ- axial clearance of the spring ring (mm)
Δr- radial clearance of the combined spring ring (mm)
Ζ- coefficient
Η- coefficient
Θ- torsion angle per unit length of the torsion bar (rad)
K-factor
-- Poisson's ratio; length factor
V-spring self-vibration frequency (Hz)
Excitation frequency (Hz) of the variable load applied to the Vr-spring
Τb- Material shear strength (Mpa)
Tj- spring working limit shear stress (Mpa)
Τo- Pulsating torsional fatigue limit of material (Mpa)
τS- material torsional yield point (Mpa)
Τ- 1- Symmetrical cyclic torsional fatigue limit of material (Mpa)
Φ-torsion angle (rad)