It is necessary to ensure matching of the velocity between the spooling and the releasing and stability of the wire tension in order to improve spooling quality and quality coherence of the clews spooled by the wire spooling device.

Development of the automatic coreless wind-up equipment with variable speed;

Failure rate expression of complex equipment based on renewal theory;

The failure rate of the complex equipment should follow the Deleinic Theorem , that is , the failure rate with increase of time is tending to the reciprocal of the mean failure interval time l/ MTBF .