BELTPRO | Spiral Drive Motor Sizing Calculator

Drum Drive

Main inputs for the cage/drum motor.

Drum diameter (mm)

Belt width (mm)

Number of tiers

Belt speed (m/min)

Belt weight (kg/m)

Product load (kg/m)

Support rails

Support friction coefficient

Drum driven radius

Advanced drum settings

Drum transmission efficiency

Drum service factor

Motor nominal speed (rpm)

Secondary Belt Drive

Inputs for the secondary belt-drive motor.

Equivalent belt length (m)

Secondary path friction coefficient

Secondary sprocket pitch diameter (mm)

Secondary transmission efficiency

Secondary service factor

The “equivalent belt length” should represent the resistance between the spiral exit and the secondary belt-drive sprockets. Fixed turns, inclines and return-path effects should be converted into an equivalent resistance before use.

Drum Drive

Required output torque

—

kN·m

Drum speed

—

rpm

Recommended motor size

—

Cage chain pull	—
Driven sprocket pull	—
Running mechanical power	—
Calculated motor power	—
Approximate reducer ratio	—
Cage surface speed	—

Secondary Drive

Required output torque

—

N·m

Shaft speed

—

rpm

Recommended motor size

—

Secondary belt pull	—
Running mechanical power	—
Calculated motor power	—
Approximate reducer ratio	—
Total recommended installed power	—

Calculation basis

Drum drive: industry-standard friction-drum spiral model using system radius, total linear load, number of tiers, support type and operating friction.

Secondary drive: simplified belt-pull calculation converted to shaft torque through the secondary sprocket pitch radius.

Power: calculated from torque and shaft speed, then corrected for transmission efficiency and service factor. The calculator selects the next standard motor size.

Preliminary sizing only. Final motor, gearbox, chain, shaft, bearing, acceleration, VFD and thermal selection must be checked against manufacturer ratings and the actual conveyor layout.