Part of the rationale for developing this motor is to avoid rare earth metals, but it mostly is a move to lower costs, said Mike Crane, who runs Continental's hybrid and electric vehicle programs.

This paper describes the reason for burnt sliding ring of coiling motor used for clamshell crane, puts forward preventative measures and Suggestions and introduces repairing standard and method.

By analysis of downside phenomenon of heavy thing lifted by the crane motor, the working principle is expounded, and the method for reduction of braking time has been summarized.