Spiral conveyor multiple drive system

A multi-drive system for a rotatable drum of a spiral conveyor, the multi-drive system comprising:

• a plurality of drive motors;
• a variable frequency drive operably coupled to each drive motor;
• a drive head operably coupled to each drive motor;
• a drive ring configured to be operably couplable to the rotatable drum, the drive ring further configured to be operably engageable with the plurality of drive heads;
• and
• a controller operably coupled to the plurality of variable frequency drive, wherein the controller causes the multi-drive system to perform operations including:
• sending an initial speed command to each variable frequency drive;
• reading, from each variable frequency drive, a nominal operating torque of each drive motor;
• computing, from the nominal operating torque of each drive motor, a first total torque of the system and a first reference torque for each drive motor;
• if required, sending a first adjusted speed command to each variable frequency drive so a first applied torque of each drive motor is substantially equivalent to the first reference torque;
• and
• monitoring the plurality of drive motors for faults, wherein, when a fault is detected and the applicable drive motor is disengaged from the system, the controller computes a second total torque of the system and a second reference torque for each remaining drive motor, and wherein the controller further sends a second adjusted speed command to each variable frequency drive of the remaining variable frequency drives, wherein the second adjusted speed command results in a second applied torque substantially equivalent to the second reference torque.