Electric motor having adjustable magnetic field, and vehicle

An electric motor having an adjustable magnetic field, comprising:

• a housing;
• a stator;
• a permanent magnet rotor;
• an excitation rotor;
• and
• an excitation ring assembly, wherein:
• each of the stator, the permanent magnet rotor, the excitation rotor, and the excitation ring assembly is located in the housing;
• the permanent magnet rotor is disposed at a radial inner side of the stator, a first air gap being formed between the permanent magnet rotor and the stator;
• the excitation ring assembly is disposed at an end wall of the housing;
• the excitation rotor is disposed between the excitation ring assembly and the permanent magnet rotor;
• the excitation ring assembly comprises an excitation ring and an excitation winding, the excitation ring having an outer ring wall and an inner ring wall, and the excitation winding being disposed between the outer ring wall and the inner ring wall;
• and
• the excitation rotor comprises a rotor core and a plurality of first permanent magnets, the rotor core being provided with a first magnetic pole cooperating portion, a second magnetic pole cooperating portion, a first magnetic pole forming section, and a second magnetic pole forming section, wherein the first magnetic pole forming section and the second magnetic pole forming section are circumferentially arranged alternately, wherein the first magnetic pole cooperating portion corresponds to the first magnetic pole forming section, wherein the second magnetic pole cooperating portion corresponds to the second magnetic pole forming section, and wherein the plurality of first permanent magnets corresponds to the first magnetic pole forming section and the second magnetic pole forming section and is arranged on the rotor core to allow the first magnetic pole forming section to be formed as a first magnetic pole and allow the second magnetic pole forming section to be formed as a second magnetic pole,
• the outer ring wall corresponds to the first magnetic pole cooperating portion, a second air gap being defined by the outer ring wall and the first magnetic pole cooperating portion;
• and
• the inner ring wall corresponds to the second magnetic pole cooperating portion, a third air gap being defined by the inner ring wall and the second magnetic pole cooperating portion.