Magnetic return path and permanent-magnet fixing of a rotor
A rotor for an electric motor having a short-circuit element that has lamination packets in which the laminations of the short-circuit element are embodied with spring elements which press from two sides against permanent magnets of the rotor and as a result center the permanent magnets in the lateral direction independently of production tolerances. After the insertion of the permanent magnets between the spring elements, the short-circuit element with the permanent magnets is potted, for instance with synthetic resin, or spray-coated with plastic. The rotor has the advantage that it compensates for production tolerances of the permanent magnets.
1. A rotor for an electrical machine, comprising
a short-circuit element ( 16 ) including a lamination packet ( 18 ) with a plurality of lamination elements ( 10 ),
a number of permanent magnets disposed on the short-circuit element,
at least one pair of fixation elements ( 14 ) on at least selected lamination elements ( 10 ), the fixation elements ( 14 ) being integral with the lamination elements ( 10 ); and
a permanent magnet ( 22 ) being retained between two fixation elements ( 14 ) of one or more lamination elements ( 10 ) of the rotor,
wherein the short-circuit element ( 16 ) comprises lamination elements ( 10 ) rotated relative to one another, between whose fixation elements ( 14 ) different permanent magnets ( 22 ) are retained, wherein the number of pairs of fixation elements on at least selected lamination elements ( 10 ) is lower than the number of permanent magnets disposed on the short-circuit element, and wherein the distance between each pair of fixation elements is essentially equal to the width of the permanent magnets.
2. The rotor of claim 1 , wherein the permanent magnets ( 22 ) are disposed on a circumference of the lamination packet ( 18 ); and wherein the fixation elements ( 14 ) press against sides ( 24 ), which are axially parallel to the rotor, of a permanent magnet ( 22 ).
3. The rotor of claim 2 , wherein the permanent magnets ( 22 ) are disposed on an outer circumference of the lamination packet ( 18 ).
4. The rotor of claim 1 , wherein each of the selected lamination elements( 10 ) have a spring element ( 14 ) as its fixation element; and wherein one permanent magnet ( 22 ) is firmly clamped between two spring elements ( 14 ) of one or more lamination elements ( 10 ).
5. The rotor of claim 2 , wherein each of the selected lamination elements ( 10 ) have a spring element ( 14 ) as its fixation element; and wherein one permanent magnet ( 22 ) is firmly clamped between two spring elements ( 14 ) of one or more lamination elements ( 10 ).
6. The rotor of claim 3 , wherein each of the selected lamination elements ( 10 ) have a spring element ( 14 ) as its fixation element; and wherein one permanent magnet ( 22 ) is firmly clamped between two spring elements ( 14 ) of one or more lamination elements ( 10 ).
7. The rotor of claim 1 , wherein the rotor has at least two lamination packets ( 18 ), rotated relative to one another, each with its own permanent magnets ( 22 ), and a rotational angle of the lamination packets ( 18 ) relative to one another deviates from a rotational angle of lamination elements ( 10 ), rotated relative to one another, of one lamination packet ( 18 ).
8. The rotor of claim 4 , wherein the rotor has at least two lamination packets ( 18 ), rotated relative to one another, each with its own permanent magnets ( 22 ), and a rotational angle of the lamination packets ( 18 ) relative to one another deviates from a rotational angle of lamination elements ( 10 ), rotated relative to one another, of one lamination packet ( 18 ).
9. A rotor for an electrical machine, comprising
a short-circuit element ( 16 ) including a lamination packet ( 18 ) with a plurality of lamination elements ( 10 ),
a number of permanent magnets disposed on the short-circuit element,
at least one fixation element ( 14 ) on at least selected lamination elements ( 10 ), the fixation elements ( 14 ) being integral with the lamination elements ( 10 ); and
a permanent magnet ( 22 ) being retained between two fixation elements ( 14 ) of one or more lamination elements ( 10 ) of the rotor,
wherein the short-circuit element ( 16 ) comprises lamination elements ( 10 ) rotated relative to one another, between whose fixation elements ( 14 ) different permanent magnets ( 22 ) are retained, and wherein a selected lamination element ( 10 ) has fewer fixation elements ( 14 ) than would be required to receive all the permanent magnets ( 22 ) of a lamination packet ( 18 ), and a plurality of lamination elements ( 10 ) rotatable counter to one another are required in order to hold all the permanent magnets ( 22 ).
10. The rotor of claim 9 , wherein the permanent magnets ( 22 ) are disposed on a circumference of the lamination packet ( 18 ); and wherein the fixation elements ( 14 ) press against sides ( 24 ), which are axially parallel to the rotor, of a permanent magnet ( 22 ).
11. The rotor of claim 10 , wherein the permanent magnets ( 22 ) are disposed on an outer circumference of the lamination packet ( 18 ).
12. The rotor of claim 9 , wherein each of the selected lamination elements ( 10 ) have a spring element ( 14 ) as its fixation element; and wherein one permanent magnet ( 22 ) is firmly clamped between two spring elements ( 14 ) of one or more lamination elements ( 10 ).
13. The rotor of claim 10 , wherein each of the selected lamination elements ( 10 ) have a spring element ( 14 ) as its fixation element; and wherein one permanent magnet ( 22 ) is firmly clamped between two spring elements ( 14 ) of one or more lamination elements ( 10 ).
14. The rotor of claim 11 , wherein each of the selected lamination elements ( 10 ) have a spring element ( 14 ) as its fixation element; and wherein one permanent magnet ( 22 ) is firmly clamped between two spring elements ( 14 ) of one or more lamination elements ( 10 ).
15. The rotor of claim 9 , wherein the rotor has at least two lamination packets ( 18 ), rotated relative to one another, each with its own permanent magnets ( 22 ), and a rotational angle of the lamination packets ( 18 ) relative to one another deviates from a rotational angle of lamination elements ( 10 ), rotated relative to one another, of one lamination packet ( 18 ).
16. The rotor of claim 12 , wherein the rotor has at least two lamination packets ( 18 ), rotated relative to one another, each with its own permanent magnets ( 22 ), and a rotational angle of the lamination packets ( 18 ) relative to one another deviates from a rotational angle of lamination elements ( 10 ), rotated relative to one another, of one lamination packet ( 18 ).
17. The rotor of claim 9 , wherein pairs of fixation elements ( 14 ) are provided for alternate permanent magnets in one selected lamination element ( 10 ).
18. The rotor of claim 9 , wherein one or more lamination elements ( 10 ) are rotated relative to one another by 360, divided by the number of permanent magnets disposed on the short-circuit element or a multiple of that number.
19. The rotor of claim 9 , wherein the lamination packet ( 18 ) includes a plurality of lamination elements ( 10 ) fixed together congruently to form a first lamination and another plurality of lamination elements ( 10 ) are fixed together congruently to form a second lamination and wherein the first and second laminations are rotated relative to one another.