Electrical machine for adjusting moving parts in a motor vehicle by motor, and also method for producing the electrical machine

1. An electric machine ( 10 ), comprising a stator ( 12 ), into which a rotor ( 14 ) can be inserted, wherein the stator ( 12 ) has two mutually opposite permanent magnets ( 18 ), which are arranged in a pole housing ( 16 ) forming a magnetic return path, and the pole housing ( 16 ) has mutually opposite flattened regions ( 20 ) between the two permanent magnets ( 18 ), with a pole housing wall ( 26 ) forming two mutually opposite magnetic consequent poles ( 22 ) on said regions, characterized in that a maximum dimension ( 25 ) of the pole housing ( 16 ) between the two mutually opposite flattened regions ( 20 ), axially in a region of the consequent poles ( 22 ), forms a width across flats ( 24 ) for an installation space of the electric machine ( 10 ), the width across flats being at most 35 mm, wherein each of the two mutually opposite flattened regions ( 20 ) of the pole housing ( 16 ) has two beads ( 28 ) which extend approximately parallel to one another in an axial direction ( 30 ) and which form an inner contour of the consequent poles ( 22 ) and a transition to holding regions ( 34 ) of the permanent magnets ( 18 ), and the pole housing ( 16 ) is closed at a first axial end ( 33 ), wherein a pole housing base ( 82 ) is formed so as to be in one piece with the pole housing ( 16 ), and a receptacle ( 83 ) for a bearing of the rotor ( 14 ) is arranged at the first end ( 33 ), wherein an opposite second axial end ( 36 ) is formed so as to be open and has a flange ( 38 ), which is connectable to a further housing part ( 40 ), wherein an axial transition region ( 45 ) is formed between the flange ( 38 ) and the beads ( 28 ), in which axial transition region a maximum dimension ( 25 ) between the mutually opposite flattened regions ( 20 ) increases along the axial direction ( 30 ), starting from the inner contour of the consequent pole region ( 22 ) towards an inner width ( 137 ) of a connecting region ( 37 ) with two inner faces ( 35 ) which are opposite one another approximately parallel to one another.

2. The electric machine ( 10 ) as claimed in claim 1 , characterized in that a wall thickness ( 54 ) of the pole housing ( 16 ) is 2% to 7% of the width across flats ( 24 ).

3. The electric machine ( 10 ) as claimed in claim 1 , characterized in that a radial wall thickness ( 56 ) of the permanent magnets ( 18 ) is 10% to 25% of the width across flats ( 24 ).

4. The electric machine ( 10 ) as claimed in claim 1 , characterized in that the rotor ( 14 ) has rotor teeth ( 66 ) for receiving electrical windings ( 64 ), which rotor teeth are in the form of radial tooth shafts ( 68 ) with tooth tips ( 70 ) arranged radially on an outside, wherein a tooth shaft width ( 72 ) in a circumferential direction ( 32 ) is 3% to 10% of the width across flats ( 24 ).

5. A modular system for forming different gear/drive units ( 130 ), wherein different pole housings ( 16 ) have an identical flange ( 38 ) and an identical connecting region ( 37 ), which are compatible with identically designed opposing flanges ( 44 ) of different gear housings ( 101 ), wherein a first pole housing ( 16 ) is designed in accordance with an electric machine ( 10 ) as claimed in claim 1 and a second pole housing ( 16 ′) has, instead of the two consequent poles ( 22 ), only one magnetic return path between two oppositely magnetized permanent magnets ( 18 ) of a two-pole motor and/or a third pole housing ( 16 ″) has, instead of the two consequent poles ( 22 ), two further permanent magnets of a 4 -pole motor.

6. The electric machine as claimed in claim 1 wherein the width across flats is at most 30 mm.

7. The electric machine ( 10 ) as claimed in claim 1 , characterized in that a wall thickness ( 54 ) of the pole housing ( 16 ) is 3% to 4% of the width across flats ( 24 ).

8. The electric machine ( 10 ) as claimed in claim 1 , characterized in that a radial wall thickness ( 56 ) of the permanent magnets ( 18 ) is 15% to 18% of the width across flats ( 24 ), and the permanent magnets ( 18 ) are in the form of ferrite magnets.

9. The electric machine ( 10 ) as claimed in claim 1 , characterized in that the rotor ( 14 ) has ten rotor teeth ( 66 ) for receiving electrical windings ( 64 ), which rotor teeth are in the form of radial tooth shafts ( 68 ) with tooth tips ( 70 ) arranged radially on an outside, wherein a tooth shaft width ( 72 ) in a circumferential direction ( 32 ) is 5% to 7% of the width across flats ( 24 ).

10. A method for producing an electric machine ( 10 ) as claimed in claim 1 , the electric machine being a servo drive in a motor vehicle, comprising the following method steps:

forming the pole housing ( 16 ) from metal by deep-drawing, wherein beads ( 28 ) for forming the consequent poles ( 22 ) are formed, and axial protrusions ( 98 ) towards a flange ( 38 ) are formed integrally on an interior of a pole housing base ( 82 ),

inserting the permanent magnets ( 18 ) into the pole housing ( 16 ) using adhesive, wherein the permanent magnets ( 18 ) are oppositely magnetized with respect to a radial direction ( 31 ), and

fixing the permanent magnets in the pole housing with magnetic holding springs ( 90 ) in such a way that free ends ( 95 ) of limbs ( 91 ) of the holding springs bear against end sides ( 93 ) of the permanent magnets ( 18 ) in a circumferential direction ( 32 ), and a bow ( 92 ) of the holding springs bears radially against axial projections ( 98 ) of the pole housing radially outside said axial projections.

11. The electric machine ( 10 ) as claimed in claim 1 , characterized in that each permanent magnet ( 18 ) forms approximately a segment of a circular ring, a central region ( 81 ) of said segment having a first inner radius ( 74 ) which is smaller than a second inner radius ( 76 ) at two outer, with respect to a circumferential direction ( 32 ), regions ( 79 ) of the permanent magnet ( 18 ).

12. The electric machine ( 10 ) as claimed in claim 11 , characterized in that the central region ( 81 ) of the permanent magnet ( 18 ) with the first inner diameter ( 74 ) comprises an angular range ( 78 ) of 50° to 60°, which is adjoined on both sides by the outer regions ( 79 ) with the second inner radius ( 76 ).

13. The electric machine ( 10 ) as claimed in claim 1 , characterized in that each permanent magnet ( 18 ) forms approximately a segment of a circular ring, a central region ( 81 ) of said segment having a first inner radius ( 74 ) which is smaller than a second inner radius ( 76 ) at two outer, with respect to a circumferential direction ( 32 ), regions ( 79 ) of the permanent magnet ( 18 ), wherein the first inner radius ( 74 ) is at most 15% larger than the outer radius ( 52 ) of the rotor ( 14 ).

14. The electric machine ( 10 ) as claimed in claim 13 , characterized in that the central region ( 81 ) of the permanent magnet ( 18 ) with the first inner diameter ( 74 ) comprises an angular range ( 78 ) of 50° to 60°, which is adjoined on both sides by the outer regions ( 79 ) with the second inner radius ( 76 ), wherein the total extent ( 80 ) of the permanent magnet ( 18 ) in the circumferential direction ( 32 ) is approximately 90°.

15. The electric machine ( 10 ) as claimed in claim 1 , wherein the first axial end ( 33 ) is the pole housing base ( 82 ) in one piece with the pole housing ( 16 ), and wherein the flange ( 38 ) is connectable to a gearbox ( 101 ).

16. The electric machine ( 10 ) as claimed in claim 15 , characterized in that a brushholder component part ( 86 ) is received in the connecting region ( 37 ), said brushholder component part extending axially from an interior of the pole housing ( 16 ) beyond the flange ( 38 ) into the gearbox connected to said flange, wherein the flange ( 38 ) has, in an angular range of the consequent poles ( 22 ), two circumferential sides ( 39 ) which are opposite one another and parallel to one another and, in an angular range ( 78 , 80 ) of the permanent magnets ( 18 ), opposite, a plurality of receptacles ( 42 ) for connecting elements ( 142 ) for fixing the axially connecting the gearbox.

17. The electric machine ( 10 ) as claimed in claim 15 , characterized in that the permanent magnets ( 18 ) are fixed in the pole housing ( 16 ) by means of magnetic holding springs ( 90 ), two limbs ( 91 ) of said magnetic holding springs each pressing the opposite permanent magnets ( 18 ) against an inner wall ( 17 ) of the pole housing ( 16 ), wherein a cavity ( 94 ) is formed between end sides ( 93 ) of the permanent magnets ( 18 ) in a circumferential direction ( 32 ) and the beads ( 28 ), into which cavity the limbs ( 91 ) engage.

18. The electric machine ( 10 ) as claimed in claim 17 , characterized in that axially free ends ( 95 ) of the limbs ( 91 ) each bear against the end sides ( 93 ) in a radially inner half of the end sides ( 93 ), and bear against inner edges ( 97 ) of the beads ( 28 ) in a transition section ( 87 ) to a bow ( 92 ), wherein the axially free ends ( 95 ) of the limbs ( 91 ) at the same time bear against a side face ( 27 ) of the beads ( 28 ) which is opposite the end sides ( 93 ) in the circumferential direction ( 32 ).

19. The electric machine ( 10 ) as claimed in claim 18 , characterized in that stops ( 98 ) are formed on the closed end ( 33 ) of the pole housing ( 16 ) on an inner side thereof, which stops are manufactured in one part with the pole housing ( 16 ), with the bow ( 92 ) arranged between the two limbs ( 91 ) bearing radially against said stops in order to avoid tipping of the bow ( 92 ) radially inwards, wherein the bow ( 92 ) bears axially against the pole housing base ( 82 ).

20. The electric machine ( 10 ) as claimed in claim 1 , wherein the further housing part ( 40 ) is a gearbox ( 101 ).

21. The electric machine ( 10 ) as claimed in claim 20 , characterized in wherein the axial transition region ( 45 ) is conical and extends 4 mm to 13 mm.

22. The electric machine ( 10 ) as claimed in claim 21 , characterized in that a brushholder component part ( 86 ) is received in the connecting region ( 37 ), said brushholder component part extending axially from an interior of the pole housing ( 16 ) beyond the flange ( 38 ) into the housing part ( 40 ) connected to said flange.

23. The electric machine ( 10 ) as claimed in claim 20 , characterized in that the permanent magnets ( 18 ) are fixed in the pole housing ( 16 ) by means of magnetic holding springs ( 90 ), two limbs ( 91 ) of said magnetic holding springs each pressing the opposite permanent magnets ( 18 ) against an inner wall ( 17 ) of the pole housing ( 16 ), wherein a cavity ( 94 ) is formed between end sides ( 93 ) of the permanent magnets ( 18 ) in a circumferential direction ( 32 ) and the beads ( 28 ), into which cavity the limbs ( 91 ) engage.

24. The electric machine ( 10 ) as claimed in claim 23 , characterized in that axially free ends ( 95 ) of the limbs ( 91 ) each bear against the end sides ( 93 ) in a radially inner region ( 96 ) of the end sides ( 93 ) and bear against inner edges ( 97 ) of the beads ( 28 ) in a transition section ( 87 ) to a bow ( 92 ).

25. The electric machine ( 10 ) as claimed in claim 24 , characterized in that stops ( 98 ) are formed on the closed end ( 33 ) of the pole housing ( 16 ) on an inner side thereof, with the bow ( 92 ) arranged between the two limbs ( 91 ) bearing radially against said stops in order to avoid tipping of the bow ( 92 ) radially inwards.