Electric machine with permanent magnet rotor

US5128575A · kind A · utility

Assignee

• Heidelberg Motor Gesellschaft fur Energiekonverter mbH · DE

Inventors

• Gotz Heidelberg · Starnberg, DE
• Peter Ehrhart · Birkenfeld, DE
• Andreas Grundl · Hersbruck, DE

Key dates

• Filing date: Sep 4, 1990
• Grant date: Jul 7, 1992
• Expiry date: Sep 4, 2010

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02K29/08
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An electric machine (2) comprising a first functional part (4) with a permanently magnetic excitation system (12) and a second functional part (6) with a conductor system (10), the first functional part (4) and the second functional part (6) being movable relative to each other along the active area (24) of an air gap. The first functional part (4) comprises--as seen progressively in the direction of relative movement (32)--an alternating sequence of permanent magnets (12) magnetized in the direction of relative movement (32), and of magnetically conductive material portions (14). The magnetically conductive material portions (14) each have--facing the active area (24)--a magnetic flux outlet area (22) which is smaller than the sum of the magnetic flux cross-sectional areas (21) of the two adjacent permanent magnets (12), so that the magnetic flux of the permanent magnets (12) is concentrated for the active area (24). The width of the permanent magnets (12), measured in the direction of relative movement (32), increases as their distance from the active area (24) increases, while the width of the magnetically conductive portions (14) decreases.