Sectionalized Electromechanical Machines Having Low Torque Ripple and Low Cogging Torque Characteristics

An electromechanical machine having rotor poles and stator poles that cooperate to generate electricity from rotation or convert electricity to rotation, comprising:

• inner and outer structures, at least one of said structures rotating relative to the other of said structures with the rotor poles disposed on the rotating structure and the stator poles disposed on the other structure, at least one of said structures including a plurality of sections;
• and
• wherein
• the poles of said structure including the plurality of sections are arranged in sets of poles as sectionalized poles,
• a set of said poles is disposed in each one of said plurality of sections and each set has two end poles, one at each section end, and
• the poles within each set are positioned as a function of the frequency of a torque ripple harmonic to be at least reduced in operation of the machine.

A segment of a rotor or stator in an electromechanical machine having rotor poles and stator poles that cooperate to generate electricity from rotation or convert electricity to rotation, the machine comprising:

• inner and outer structures, at least one of said structures rotating relative to the other of said structures with the rotor poles disposed on the rotating structure and the stator poles disposed on the other structure, at least one of said structures including a plurality of sections;
• wherein
• the poles of said structure including the plurality of sections are arranged in sets of poles as sectionalized poles,
• a set of said poles is disposed in each one of said plurality of sections and each set has two end poles, one at each section end,
• the sectionalized poles within each set are arranged at a section pole pitch, the section pole pitch being a function of the frequency of a torque ripple harmonic to be at least reduced in operation of the machine,
• the end poles of adjacent sections are spaced at a boundary pole pitch, the boundary pole pitch being a function of the section pole pitch;
• and
• wherein said segment is configured and dimensioned to form one of said plurality of sections with each said section configured as one of a plurality of removable such segments.

A method for reducing torque ripple and cogging torque in an electromechanical machine having rotor poles and stator poles disposed on relatively rotating structures that cooperate to generate electricity from rotation or convert electricity to, the method comprising:

• conceptually dividing at least one of the relatively rotating structures into a plurality of sections to provide a sectionalized structure with each section having ends adjacent a next section;
• arranging the poles of the sectionalized structure in a plurality of sets of poles, each set disposed within one said section and having two end poles, one at each section end;
• and
• positioning adjacent poles within each set of poles as a function of the frequency of the torque ripple harmonic to be reduced.

An electromechanical machine having rotor poles and stator poles that cooperate to generate electricity from rotation or convert electricity to rotation, comprising inner and outer structures, at least one of said structures rotating relative to the other of said structures with the rotor poles disposed on the rotating structure and the stator poles disposed on the other structure, at least one of said structures including a plurality of sections, wherein:

• the poles of said structure including the plurality of sections are arranged in sets of wound poles formed on teeth having a depth;
• a set of said poles is disposed in each one of said plurality of sections and each set has two end poles, one at each section end;
• the end poles are spaced from the section ends by an end space at each section end, the end space having a width of approximately the distance from the end pole winding to the section end, and a depth of approximately the depth of the wound pole teeth to define an end space area;
• and
• an unwound tooth is disposed in each end space, the unwound teeth occupying not more than 90% of said end space area.