Motor with a disk rotor

US4394594A · kind A · utility

Assignee

• Papst Motoren GmbH & Co KG · DE

Inventors

• Fritz Schmider · Hornberg, DE
• Rolf Muller · St. Georgen, DE

Key dates

• Filing date: Jul 24, 1980
• Grant date: Jul 19, 1983
• Expiry date: Jul 24, 2000

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02K3/47
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

Slow-running brushless d.c. motors with a disk rotor, a flat air gap and an iron-free stator winding made up of a number of coils are particularly suitable for direct drive of sound recording and reproducing equipment at a highly steady and controlled speed. The iron-free coils are arranged in a one-layer winding arrangement connected to form a plurality of phase windings, each comprising a pair of magnetically oppositely poled coils and rotor position sensing means, such as a Hall generator, are provided for controlling the currents in the phase winding so as to obtain four-current pulses per rotor rotation angle of 360 electrical degrees and to set up a rotary magnetic field driving the permanent magnet rotor. Two sets of coils are shown in the stator winding, each set comprising at least one pair electrically connected with each other and oppositely poled and spaced from each other by (2n+1).multidot.180 electrical degrees, where n is a low positive integer. Double wound coils are shown with the two wires of the coils of a set being wound bifilarly and connected to form two-phase windings per set, with the width of the individual coils substantially greater than 180 electrical d…