Patent Number: 7,355,309

Title: Permanent magnet rotor for a direct drive generator or a low speed motor

Abstract: In order to provide a less expensive generator, a rotor using nonmagnetic beams is disclosed. The rotor includes a magnetic steel rim connected to a main generator shaft by a hub. The magnetic rim supports the components of the rotor, which includes a plurality of magnets and pole pieces. The pole pieces are connected to the rim with non-magnetic standoffs and nonmagnetic fasteners. The magnets are supported radially by nonmagnetic beams. The magnets are retained tangentially by pole pieces and radially by wedges. The components of the rotor are further retained axially between plates coupled to the rim and a shoulder on the pole pieces.

Inventors: Costin; Daniel (Chelsea, VT), John; Vinod (Montbellier, VT)

Assignee: Northern Power Systems, Inc.

International Classification: H02K 21/12 (20060101)

Expiration Date: 2020-04-08 0:00:00