Rotor sheet, rotor, and electrical machine, and method for producing a rotor

1. A rotor sheet ( 1 ), for a permanently excited electrical machine ( 49 ), comprises a central cut-out ( 3 ) for a shaft ( 53 ) and is divided into a plurality of sectors ( 4 ), each of the plurality of sectors ( 4 ) including a first half sector ( 5 ) and a second half sector ( 6 ) that is delimited from the first half sector ( 5 ) by a radial central line ( 7 ), a first through-opening configuration ( 8 ), including a magnet pocket through-opening ( 9 ) that has two parallel edge lines ( 15 , 16 ) extending along an extension direction ( 17 ), being formed inside the first half sector ( 5 ), and a further through-opening configuration ( 14 ) that is mirror-symmetrical to the through-opening configuration ( 8 ) with respect to the central line ( 7 ), being formed inside the second half sector ( 6 ), wherein the first through-opening configuration ( 8 ) includes a relief through-opening ( 10 ) that is located completely in the first half sector ( 5 ) and has a radially innermost point ( 23 ) located further to the inside than a radially innermost point ( 24 ) of the magnet pocket through-opening ( 9 ), the relief through-opening ( 10 ) being inscribed inside an incircle-free trapezoid ( 25 ) having two bases ( 26 , 27 ) extending parallel to the central line ( 7 ), wherein a first base ( 26 ) of the two bases ( 26 , 27 ) is located closer to the central line ( 7 ) than a second base ( 27 ) of the two bases ( 26 , 27 ), a first leg ( 28 ) that extends on a first straight line ( 29 ) having a first angular spacing ( 32 ) from the central line ( 7 ), and a second leg ( 30 ) that extends on a second straight line ( 31 ) having a second angular spacing ( 33 ) from the central line ( 7 ), the first straight line ( 29 ) and the second straight line ( 31 ) intersecting on the side of the first base ( 26 ) at an acute angle, and the first angular spacing ( 32 ) and the second angular spacing ( 33 ) each being larger than a magnet pocket angular spacing ( 19 ) of the extension direction ( 17 ) from the central line ( 7 ).

2. The rotor sheet according to claim 1 , wherein the relief through-opening ( 10 ) has a first edge line ( 34 ) that extends at least along a portion of the first straight line ( 29 ), and/or a second edge line ( 35 ) that extends at least along a portion of the second straight line ( 31 ).

3. The rotor sheet according to claim 2 , wherein a ratio (a2/a1) of a largest section (a2) that is placed perpendicularly onto the first edge line ( 34 ) and ends on the second edge line ( 35 ), to a smallest section (a1) that is placed perpendicularly onto the first edge line ( 34 ) and ends on the second end line ( 35 ), is at least 1.00, preferably at least 1.15, and further preferably at least 1.30, and/or no more than 1.85, preferably no more than 2.10, and further preferably no more than 2.60.

4. The rotor sheet according to claim 1 , wherein a difference ( 36 ) between the first angular spacing ( 32 ) and the magnet pocket angular spacing ( 19 ) is at least 23.5°, preferably at least 25°, and further preferably at least 26.5°, and/or no more than 31°, preferably no more than 38°, and further preferably no more than 45° and/or a difference ( 37 ) between the second angular spacing ( 32 ) and the magnet pocket angular spacing ( 19 ) is at least 12°, preferably at least 15°, and further preferably at least 21° and/or no more than 24°, preferably no more than 25°, and further preferably no more than 30°.

5. The rotor sheet according to claim 1 , wherein a ratio (b2/b1) of a distance (b2) between the first base ( 26 ) and the central line ( 7 ) to a distance (b1) between the radially innermost point ( 24 ) of the magnet pocket through-opening ( 9 ) and the central line ( 7 ) is at least 0.60, preferably at least 1.2, and further preferably at least 1.9, and/or no more than 2.2, preferably no more than 2.3, and further preferably no more than 2.5.

6. The rotor sheet according to claim 1 , wherein a ratio (c1/ra) of an outer radial distance (c1) of the radially outermost point ( 38 ) of the relief through-opening ( 10 ) to an outside radius (ra) of the rotor sheet ( 1 ) is at least 0.21, preferably at least 0.25, and further preferably at least 0.27, and/or no more than 0.29, preferably no more than 0.30, and further preferably no more than 0.32.

7. The rotor sheet according to claim 1 , wherein a ratio (d1/ra) of an inner radial distance (d.sub.1) of the radially innermost point ( 23 ) of the relief through-opening ( 10 ) to an outside radius (ra) of the rotor sheet ( 1 ) is at least 0.55, preferably at least 0.60, and further preferably at least 0.62, and/or no more than 0.65, preferably no more than 0.68, and particularly further preferably no more than 0.70.

8. The rotor sheet according to claim 1 , wherein the relief through-opening ( 10 ) has a further edge line ( 39 ) that is located on at least portion of a third straight line ( 40 ) intersecting the second leg ( 30 ) and the second base ( 27 ).

9. The rotor sheet according to claim 1 , wherein the first through-opening configuration ( 8 ) has a further magnet pocket through-opening ( 11 ) that has two parallel edge lines ( 42 , 43 ) extending along a further extension direction ( 44 ), straight lines on which a respective edge line ( 42 , 43 ) of the further magnet pocket through-opening ( 11 ) is located intersecting the central line ( 7 ) radially further to the outside than straight lines on which a respective edge line ( 15 , 16 ) of the first magnet pocket angular spacing ( 9 ) is located.

10. The rotor sheet according to claim 1 , comprising at least one balancing through-opening ( 12 , 13 ) that forms part of the first through-opening configuration ( 8 ) and the radially innermost point of which is located further to the inside than the radially innermost point ( 23 ) of the relief through-opening ( 10 ).

11. A rotor ( 51 ) for a permanently excited electrical machine ( 49 ), comprising a rotor laminated core ( 52 ) formed by a plurality of stacked rotor sheets ( 1 ) according to claim 1 , a permanent magnet magnetic element ( 54 , 55 ) being arranged inside a respective magnet pocket formed by magnet pocket through-openings ( 9 , 11 ) located on top of one another.

12. An electrical machine ( 49 ) for a vehicle ( 48 ), comprising a stator ( 50 ) and a rotor ( 51 ) according to claim 11 mounted rotatably with respect to the stator.

13. A method for producing a rotor ( 51 ) for a permanently excited electrical machine ( 49 ), a plurality of rotor sheets ( 1 ) according to claim 1 being arranged in such a way to form a rotor laminated core ( 52 ) that respective through-opening configurations ( 8 , 14 ) are congruent.

14. The method according to claim 13 , wherein a rotor sheet according to claim 10 is used, the rotor laminated core ( 52 ) being balanced by introducing at least one balancing weight ( 56 ) into the balancing through-openings ( 12 , 13 ) of at least one through-opening configuration ( 8 , 14 ) of a respective rotor sheet ( 1 ).

15. The method according to claim 13 , wherein the rotor laminated core ( 52 ) is balanced by creating at least one through-opening through the arranged rotor sheets ( 1 ).