Title:
PERMANENT MAGNETS FOR A GENERATOR WITH REDUCED COGGING
Document Type and Number:
WIPO Patent Application WO/2012/017303
Kind Code:
A3
Abstract:
The invention concerns a permanent magnet generator with reduced cogging effect, comprising a stator (4) provided with a plurality of stacks of tooth- shaped magnetic laminations (6; 306) having respective electric windings (10) arranged radially around the rotation axis (8) of the generator, which alternate with a plurality of slots (12; 312) having a correspondent opening (14; 314), and a rotor (2) provided with a plurality of permanent magnets (16; 116; 216) arranged radially spaced from the rotation axis (8) of the generator, in which the permanent magnets (16; 116; 216) have skew edges. The air gap (20) between the stacks of tooth-shaped magnetic laminations (6; 306) and the permanent magnets (16; 116; 216) is variable; the magnets are variable air gap magnets in which the top and bottom sides of the magnets define an internal curved surface and an external curved surface having the same curvature direction and defining, in cross section, with respect to the height of the magnet in the direction of the rotation axis, non-concentric circle arcs with different radiuses (R1, R2, R11, R12), so that the distance between the two surfaces that represents the thickness of the magnets varies in its cross section; the rotor (2) is outside the stator (4) and the circle arc defined by the radius (Ri; R1; R11) of the internal curved surface in cross section, located in front of the stacks of tooth-shaped magnetic laminations (6), is not concentric with the circle arc defined by the radius (Rs) corresponding to the cylindrical surface defined by the stacks of tooth-shaped magnetic laminations (6).
Inventors:
BATTISTELLA FRANCESCO (IT)
Application Number:
PCT/IB2011/001814
Publication Date:
June 14, 2012
Filing Date:
August 04, 2011
Export Citation:
Assignee:
NUOVA SACCARDO MOTORI S R L (IT)
BATTISTELLA FRANCESCO (IT)
BATTISTELLA FRANCESCO (IT)
International Classes:
H02K1/27; H02K7/18; H02K29/03
Domestic Patent References:
| WO2010051691A1 | 2010-05-14 |
Foreign References:
| JP2006304407A | 2006-11-02 | |||
| US20060038457A1 | 2006-02-23 | |||
| US20040070300A1 | 2004-04-15 | |||
| US20090224622A1 | 2009-09-10 |
Attorney, Agent or Firm:
BONINI, Ercole (Corso Fogazzaro 8, Vicenza, IT)
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