Roller Conveyor Power and Torque Calculator

On a chain driven live roller conveyor every roller is driven, so the drive has to overcome the rolling resistance of the load and the rollers, gravity on an incline, and the losses in each roller-to-roller chain loop. The rolling pull for the load plus the roller mass along the conveyor is:

F = (load + w_r × L) × g × (μ × cosθ + sinθ)

Each chain loop wastes a little of the power passing through it, typically about 1% per roller. This calculator adds that as a simple factor:

F_total = F × (1 + loss × N_rollers)

The drive torque is F_total times the drive roller radius, and the motor power and gearbox ratio follow in the same way as on the belt conveyor calculator.

Long CDLR runs are usually split into zones of 10 to 15 m, each with its own drive, because chain losses grow with the number of rollers. Check chain working load and roller ratings with your supplier.

Basic / Advanced

Basic assumes ideal conditions: no chain losses, roller mass ignored, 100% efficient drive, service factor 1.0. Advanced adds roller mass, length, roller count, chain loss, efficiencies and service factor.

Maximum load

Total product mass on the rollers at the worst moment.

Roller mass per metre

Mass of the rotating rollers per metre of conveyor. It adds to the rolling resistance.

Drive roller diameter

Diameter that converts pull to torque and speed to rpm, normally the roller (or drive sprocket) diameter.

Number of rollers, chain loss

Every driven roller has a chain loop. About 1% loss per roller is typical for clean, lubricated roller chain.

Rolling resistance μ

Effective coefficient for load on rollers: 0.03 for precision bearings and rigid loads, up to 0.05 for heavy, soft or dirty conditions.

Incline angle

Live roller conveyors are usually limited to about 5°; above that, cartons may slide 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.