Arrangement to compensate a non-uniform air gap of an electric machine

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.