Large-tonnage traction machine with self-locking protection function for elevator

The invention discloses a large-tonnage traction machine with a self-locking protection function for an elevator, and belongs to the field of large-tonnage traction machines. After the traction machine breaks down and is powered off, a stop pad can move towards a connecting shaft until the connecting shaft is clamped, and the connecting shaft only slows down rotation; meanwhile, an outer protection pipe can tear the stop pad and release a filling ball under the action of a notch groove, at the moment, heat generated by friction between the connecting shaft and the stop pad can melt a hot melting block, the thermosetting material is released under the extrusion action of the connecting shaft and the stop pad, and due to the effect that the surface of an elastic spherical shell in the filling ball protects a fiber cluster, the thermosetting material is not easy to overflow in a large amount, and can be quickly cured and lock the connecting shaft under the action of heat, so that the acceleration generated in th