V and Flat Belt Design Guide, Equations, and Information

V and Flat Belt Design and Engineering Data

Belt Tensions, Pretensions, Torques, Power and Configurations

Description	Equation
Torque transmitted by a belt
Rated power of belt
Tension of flat belt
Tension of V-belt
Centrifugal loading
Belt length (open)
Belt length (closed)
Angle of contact Note: Use (+) for large pulley and X-belts Use (-) small pulley Angle in radians

Variable Declarations

P = tension in belt (1-tight, 2-slack)
r = pulley radius
T = Torque (in-lb)
w = rpm
f = coefficient of friction (leather = 0.3, rubber = 0.25 Flat belt (use .5123 for V-belts)
B = 1/2 groove angle
C = distance between shafts (in.)
D₁ = sheave diameter
D₂ = sheave diameter
L = Length
m' = mass/unit length of belt
Φ = Angle of contact