Spindle drive mechanism using asynchronous motors - held at constant speed by continuous monitoring of optimum supply voltage

摘要

Spindle speed variation in spinning machines or false-twist texturising machines which have high-speed spindles individually driven by asynchronous motors is minimised by continuously adjusting the voltage of the electrical supply to each motor towards the value which gives the smallest speed variation for a given variation in load. Device to effect the method comprises a clutch mechanism which allows a supplementary load to be transiently connected to a spindle, and a measuring unit which records the associated change in spindle speed. The supply voltage to the motor is then altered slightly and the process is repeated. The supply voltage is geld at the value which produces the least variation in spindle speed by continuous repeated measurements. Cheap, reliable asynchronous motors can be used in place of expensive and sensitive synchronous motors, but yet produce high-quality yarns with constant twist levels.