Tangential Belt Drive System
topic
Tangential drive uses a continuous flat belt (25–30 mm wide, polyurethane or rubber) running against the whorls of all spindles on one side of the ring frame, driven by a motor at one end. Belt tension is maintained by guide rollers at 15–25 N pre-tension. Belt slip on the whorl causes spindle speed variation (1–3% between spindles), directly causing count and twist variation between positions. Modern frames use individual spindle motors (one per spindle) eliminating belt-related variation.
Role
Tangential belt condition and tension are critical for spindle speed uniformity across a 1000-spindle frame. A worn belt with 5% speed variation between positions produces twist variation of 5%, which causes fabric barre visible to the naked eye. Belt replacement scheduling and tension monitoring are therefore direct quality interventions, not just mechanical maintenance.