Structures theory of reluctance step motors

Reluctance step motors are obviously adapted to such functions, but the number of steps depends on the product of the numbers of phases and of rotor teeth. In usual structures (those with regularly displayed stator salient poles, slotted or not) these numbers must obey certain relations, so that many numbers of steps are impossible to obtain, including, obviously, all the odd numbers. This article generalizes the structures of step motors and presents the methods of designing motors with a “dissymmetrical” stator. The theory also includes the usual “symmetrical” structures as well. The authors intend to show the possibility of obtaining almost any number of steps by changing the regular, symmetrical disposition of the poles into an irregular, dissymmetrical one, which allows odd numbers of rotor teeth, in particular. They also build a simple theory of the generalized structures of salient pole step motors. Various examples of dissymmetrical motors are given, which provide peculiar numbers of steps that can be useful in specific applications (robotics, angular and linear measurements, etc.)