About Torsion Springs

Torsion springs have at least one and a half coils. A torsion spring is exposed to external forces acting in planes perpendicular to the coiling axis, inducing a torque in the coiling or uncoiling direction. The torque is carried by the working and the supporting arms. Active coils change their diameter during the function.

Dimensions

d

wire diameter [mm, in]

D

mean spring diameter [mm, in]

D 1

outside spring diameter [mm, in]

L 0

length of coiled spring part for free spring state, in general [mm, in]

R 1

arm of working force induced by the spring [mm, in]

R 2

arm of support force induced by the spring [mm, in]

M 1

torque induced by the pre loaded spring [Nm, lb ft]

M 8

torque induced by the fully loaded spring [Nm, lb ft]

W 8

deformation energy induced by the fully loaded spring [J, ft lb]

ϕ 1

angle deflection of working arm in the pre loaded state [°]

ϕ 8

angle deflection of working arm in the fully loaded state [°]

ϕ h

angle of working stroke [°]

ρ 0

angle of arms in the free state [°]

F

working force induced on the R1 arm, in general [N, lb]

Coiling

  1. Right (usually)
  2. Left (must be notified in words)

States

  1. Free: the spring is not loaded (index 0)
  2. Preloaded: smallest working load is applied to the spring (index 1)
  3. Fully loaded: maximum working load is applied to the spring (index 8)
  4. Limit : the spring is deflected to the solid length (index 9)
Note: Variables connected with springs are presented here with their symbols, identifiers, and units and with appropriate calculation formulas and instructions.