Patent ID: 8558426
Filing Date: 2013-10-15
Classification: H02K,Y02E

Abstract:
1. An arrangement to compensate for a non-uniform air gap in an electric machine, comprising: a stator arrangement; a rotor arrangement; an air gap; and a plurality of magnets, wherein the rotor arrangement rotates around a longitudinal axis, wherein at least a plurality of first parts of the rotor arrangement interact with a plurality of second parts of the stator arrangement to generate electrical power, wherein the air gap is defined by a distance between the plurality of first parts of the rotor arrangement and the plurality of second parts of the stator arrangement, wherein the plurality of second parts of the stator arrangement are opposite to the plurality of first parts of the rotor arrangement along a certain length, wherein a cross section of the air gap changes along the certain length, so the air gap is not uniform in view to the referred certain length, wherein the rotor arrangement comprises the plurality of magnets, and wherein a magnetic flux density in the air gap is changed dependent on the cross section of the air-gap, wherein a size or a height of the plurality of magnets is changed along the non-uniform air gap, wherein the air gap includes on a first side a first width and the air gap includes on a second side a second width, wherein the plurality of magnets include a first height in reference to the first width at the first side, and wherein the plurality of magnets include a second height in reference to the second width at the second side, while the first height is lower than the second height, wherein the plurality of magnets are permanent magnets, wherein the plurality of magnets are arranged on a plurality of basements to balance the different heights of the plurality of magnets in relation to the air gap, and wherein a first plurality of basements of the magnets, which are close to the first side of the air gap, are lower than a second plurality of basements of the magnets, which are close to the second side of the air gap.