Chain Conveyor Power and Torque Calculator

A drag or slat chain slides on wear strips, so the pull comes from sliding friction on both the loaded carry side and the empty return side, plus gravity on an incline. With chain mass w per strand per metre, s strands and length L:

F_carry = (load + w × s × L) × g × (μ × cosθ + sinθ)

F_return = w × s × L × g × (μ × cosθ − sinθ), not less than 0

On a steep incline the returning chain runs downhill and helps the drive, so the return side pull is limited to zero. If product is held back while the chain keeps running (accumulation), the chain also slides under the product, adding load × g × μ_p. The total is converted to torque at the drive sprocket pitch diameter, where the pitch diameter of a sprocket is p / sin(180°/z).

This simplified method ignores sprocket and bearing losses, chain articulation and catenary tension. Check the result against the chain's allowable working load per strand with your chain supplier.

Basic / Advanced

Basic assumes ideal conditions: chain mass ignored, no accumulation, 100% efficient drive, service factor 1.0. Advanced adds chain mass, strands, length, accumulation, efficiencies and service factor.

Drive sprocket

Enter the pitch diameter directly, or the number of teeth and the chain pitch and the calculator works out the pitch diameter.

Maximum load

Total product mass on the chain at the worst moment.

Chain mass, strands

Mass of one strand per metre (from the chain catalogue) and how many strands run side by side.

Wear strip friction μ

Chain sliding on UHMW is about 0.15, nylon about 0.20 and steel about 0.30 when lubricated or clean.

Accumulation

Select Yes when product can be stopped while the chain keeps running. μ_p is the friction between product and chain.

Incline angle

Chain angle above horizontal. Steep inclines may need flights or pushers to stop product sliding back.

Efficiencies, service factor

Helical gearboxes are about 0.94 to 0.97, worm gearboxes 0.50 to 0.90. A service factor of 1.25 to 1.5 suits steady duty.

Motor poles, Auto

Auto picks a 4 pole motor (1440 rpm at 50 Hz, 1740 rpm at 60 Hz) when the gearbox ratio is between 5 and 150. If the ratio would be above 150 it steps to a 6 or 8 pole motor. A ratio below 5 needs a larger drive diameter or a low-ratio gearbox, because a slower motor would lower the ratio further. 2 pole motors are never picked automatically.

Custom motor

Enter the nameplate speed and power of an existing motor. It passes when its rated power covers the required power times the service factor, is marginal when it only covers the required power, and is undersized below that.

VSD

With a variable speed drive the conveyor speed changes in proportion to frequency. Below about 25 Hz a standard motor may need forced cooling at full torque.