Belt Power from Tension and Speed

P = (T1 - T2) V / 33000 hp, with V = pi D N / 12 ft/min. The point people miss: only the DIFFERENCE of the tight- and slack-side tensions (the effective tension Te = T1 - T2) does work -- the average tension just clamps the belt for grip and transmits nothing. A 250-to-100 lb drive on a 6 in sheave at 1,750 rpm runs 2,749 ft/min and passes 12.5 HP; a tighter 400-to-250 lb drive keeps the same Te of 150 and the same 12.5 HP while carrying far more total tension into the bearings. Over-tensioning buys wear, not capacity. A design aid; the belt/sheave ratings and wrap angle govern.

V = pi D N / 12 (ft/min); Te = T1 - T2; P = Te V / 33000 (hp).

The belt power relation P = (T1 - T2) V / 33000, first-principles as in Machinery's Handbook / the Gates Industrial Drive Design Manual, by name.

The power-from-effective-tension relation is a standard first-principles result; the tensions and speed come from the drive. Free at gates.com/literature.

Estimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.

Field names used by the API: tight_side_tension_lb, slack_side_tension_lb, sheave_diameter_in, sheave_rpm, power_hp, belt_speed_fpm, effective_tension_lb

• Effective tension only Te = T1 - T2 does work; the average tension is grip, not powerbelt-drive mechanics
• Belt speed V = pi D N / 12 ft/min from the sheave pitch diameter and rpmfirst-principles geometry
• Design aid the belt/sheave ratings, wrap angle, and manufacturer power tables govern the selectionscope of this tile