Multi-V Belts

Engineering - Formulas

Unknown	Where	Formula
Horsepower	hp = horsepower T_d = design torque (oz-in) rpm = motor speed (rev/min)	hp = T_d x rpm / 1.0084 x 10⁶
Power	PW = power(kw) hp = horsepower	PW = 0.7457 x hp
Center Distance (using same size pulleys for driveR and driveN)	CD = center distance (in) P = pitch (in) N_B = number of teeth on belt N_P = number of teeth on pulley	CD = P x (N_B - N_p) / 2
Center Distance (using unequal size pulleys for driveR and driveN)	CD = center distance (in) PL = belt pitch length (in) D = large pulley pitch dia. (in) d = small pulley pitch dia. (in)	CD = b + √b² - [8 x (D - d)²]/8 b = (2 x PL) - [Π x (D + d)]
Belt Pitch Length	PL = belt pitch length (in) CD = center distance (in) D = large pulley pitch dia. (in) d = small pulley pitch dia. (in)	PL=(2 x CD) + [ 1.57 x (D + d)] + (D - d)² / (4 x CD)
Belt Speed	V = belt speed (in/sec) D_r = pitch diameter of driveR pulley rpm = speed of driveR	V = D_r x π x rpm / 60
Arc of Contact (smaller pulley)	∅ = arc of contact (°) PL = belt pitch length (in) P = tooth pitch (in) CD = center distance (in)	∅ = 180 - 57.3 x (D - d) / CD
Effective Tension	T_e = effective tension (lb) T_d = design torque (oz-in) r = pulley radius (in)	Te = T_d / (16 x r)
Design Torque	T_d = design torque (oz-in) T_pk = peak torque (oz-in)	T_d = T_pk / T.I.M. Factor