Abstract: Slotless and toothless wound stators for electrical machines, in particular brushless DC motors, include removable temporary teeth at opposite ends of an iron cylinder with smooth inner wall end-to-end, an electrical winding without sypporting form against the inner wall and between and around the teeth, an expandable cylinder for retaining the winding against the smooth inner wall. The completed stators lack teeth and slots from end-to-end of the iron cylinder, have the winding placed against the smooth inner wall of the iron cylinder, and have the reformed plastic cylinder pressing and retaining the winding against the smooth inner wall.

Abstract: Slotless and toothless wound stators are produced for electrical machines, in particular brushless DC motors, by providing temporary teeth at opposite ends of an iron cylinder with smooth inner wall end-to-end, placing an electrical winding without supporting form against the inner wall and between and around the teeth, pressing the winding against the smooth inner wall by an expandable retaining cylinder, and removing the temporary teeth. A temporary fixture can provide the temporary teeth by radially inwardly extendable and radially outwardly retractable fingers, the fingers being removed by outward retraction through cam means. Alternately, plastic end members with teeth may be glued to opposite ends of the smooth-walled iron cylinder to provide temporary teeth, the teeth being machined off after positioning the winding.