Related Resources: material science

Cylindrical Shear Spring Design Equation and Calculator

Springs of rubber bonded to metal are made in a wide variety of configurations. The rubber is usually in shear and, because of the high internal damping, such springs are used for limiting vibrations.

Cylindrical shear spring with axial load applied design equations and calculator, load P

Symbols used:
Do = Outside diamater of rubber bushing, (mm, in)
Di = Inside diamater of rubber bushing, (mm, in)
P = Loading Force, (N, lbs)
h = Rubber thickness, (mm, in)
G = Shear modulus

Shaft Rubber Bushing Dampner

Design equations:

Maximum Shear Stress τm = P / π h Di
Deflection y = [ P / ( 2 π h G ) ] ln ( Do / Di )
where G = shear modulus.

Modulus and strength of rubber
G = 0.3 to 1.2MPa
E = 0.9 to 3.6 MPa
Allowable shear stress = 0.2 to 0.4 MPa
Deflection limited to 10% to 20% of free height.