Internal rotor with rotor plate having sprung web-shaped clamping element to clamp the magnet and two recesses

Patent metadata

Field	Value
Publication number	US-11424649-B2
Application number	US-201816468991-A
Country	US
Kind code	B2
Filing date	Feb 9, 2018
Priority date	Feb 22, 2017
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

An internal rotor for an electric motor has a laminated rotor core with a multiplicity of rotor plates, and multiple pockets in each of which pocket a rotor magnet is at least partially arranged. The rotor plates have first recesses for forming the pockets and at least a first rotor plate which has at least a second recess associated with a first recess. A sprung web-shaped clamping element is formed between the second recess and the associated first recess, and tensioned toward the second recess by the associated rotor magnet to apply a force to the associated rotor magnet toward the first recess in order to hold the associated rotor magnet in the pocket. A rotor plate holds a rotor magnet in a pocket of a laminated rotor core.

First claim

The invention claimed is:

1. An internal rotor ( 150 ) for an electric motor ( 100 ),
which internal rotor ( 150 ) has a laminated rotor core ( 200 ; 600 ) with a multiplicity of rotor plates ( 310 ), which laminated rotor core ( 200 ; 600 ) has multiple pockets ( 210 ) in each of which a rotor magnet ( 221 ; 621 ) is at least partially arranged,
which rotor plates have first recesses ( 211 ; 611 ) for forming the pockets ( 210 ),
which rotor plates ( 310 ) have at least a first rotor plate ( 311 ),
which first rotor plate ( 311 ) has at least a second recess ( 230 ; 231 - 236 ; 631 ), which second recess ( 230 ; 231 - 236 ; 631 ) is associated with a first recess ( 211 - 216 ; 611 ), wherein the ratio of the angular extent (phi_R 2 ) of the second recess ( 230 ; 231 - 236 ; 631 ) to the angular extent (phi_RM) of the associated rotor magnet ( 221 ; 621 ) is in the range of 0.4 to 0.8,
wherein, between the second recess ( 230 ; 231 - 236 ; 631 ) and the associated first recess ( 211 - 216 ; 611 ), a sprung web-shaped clamping element ( 291 ; 691 ) is formed, which clamping element ( 291 ; 691 ) is tensioned toward the second recess ( 231 - 236 ; 631 ) by the associated rotor magnet ( 221 , 621 ), and which clamping element ( 291 ; 691 ) as a result applies a force to the associated rotor magnet ( 221 ; 621 ) toward the first recess ( 211 - 216 ; 611 ) in order to hold the associated rotor magnet ( 221 ; 621 ) in the pocket ( 210 ),
wherein the first rotor plate ( 311 ) has a first contour,
wherein the rotor plates ( 310 ) have at least a second rotor plate ( 312 ), which second rotor plate ( 312 ) has a second contour, wherein the second contour covers the first contour in the area of the second recess ( 231 ) at least in sections, and
wherein the second rotor plate ( 312 ) at least partially covers the clamping element ( 291 ; 691 ), in order to limit in this manner, in an arrangement of the second rotor plate ( 312 ) on the first rotor plate ( 311 ), a movement of the clamping element ( 291 ; 691 ) of the first rotor plate ( 311 ) in an axial direction toward the second rotor plate ( 312 ), while however allowing a movement of the clamping element ( 291 ; 691 ) in a direction perpendicular to the axial direction.

2. The internal rotor ( 150 ) according to claim 1 , wherein the ratio of the angular extent (phi_R 2 ) of the second recess ( 230 ; 231 - 236 ; 631 ) to the angular extent (phi_RM) of the associated rotor magnet ( 221 ; 621 ) is in the range of 0.5 to 0.8.

3. The internal rotor ( 150 ) according to claim 1 ,
wherein the second recess ( 231 - 236 ; 631 ) is adjacent to the first recess ( 211 - 216 ; 611 ) in radial direction.

4. The internal rotor ( 150 ) according to claim 1 ,
wherein the clamping element completely separates from one another the first recess ( 211 - 216 ; 611 ) and the second recess ( 231 - 236 ; 631 ) within the first rotor plate ( 311 ).

5. The internal rotor ( 150 ) according to claim 1 ,
wherein the second recess ( 231 ; 631 ) and the associated first recess ( 211 ; 611 ) have a common central axis.

6. The internal rotor ( 150 ) according to claim 1 ,
wherein the extent of the second recess ( 231 ; 631 ) in tangential direction is at least 40% of the extent of the rotor magnet ( 221 ; 621 ) in tangential direction.

7. The internal rotor ( 150 ) according to claim 1 ,
wherein the rotor magnet ( 221 ; 621 ) has a first side facing the clamping element ( 291 ; 691 ), and
wherein the clamping element ( 291 ; 691 ) in the tensioned state has a shape which is not exactly complementary to the shape of the first side, in order to hereby clamp the rotor magnet ( 221 ; 621 ) in the first recess ( 211 ; 611 ) on the first side just in a partial area.

8. The internal rotor ( 150 ) according to claim 1 , wherein the clamping element ( 291 ; 691 ) extends from the first recess ( 211 ; 611 ) to the second recess ( 231 ; 631 ).

9. The internal rotor ( 150 ) according to claim 1 , wherein the rotor core ( 200 ) has a passage opening ( 240 ) for receiving a shaft ( 40 ), and wherein the second recess ( 231 ) is arranged in the area between the passage opening ( 240 ) and the associated first recess ( 211 ).

10. The internal rotor ( 150 ) according to claim 1 , wherein the clamping element ( 291 ; 691 ) has a local convexity ( 292 ; 692 ) in radial direction.

11. The internal rotor ( 150 ) according to claim 1 , wherein the first rotor plate ( 312 ) has a second rotor plate ( 312 ) on one side or on both sides.

12. The internal rotor ( 150 ) according to claim 1 , wherein, on one axial end or the two axial ends of the laminated rotor core ( 200 ; 600 ), at least five second rotor plates ( 312 ) are provided before a first rotor plate ( 311 ) is provided.

13. The internal rotor ( 150 ) according to claim 1 , wherein the laminated rotor core ( 200 ; 600 ) has a number n of first rotor plates ( 311 ) chosen from 2≤n≤6.

14. The internal rotor ( 150 ) according to claim 1 , wherein the first rotor plate ( 312 ) has for each first recess ( 211 - 216 ) at least a clamping element ( 291 ; 691 ).

15. An electric motor ( 100 ) with an external stator ( 28 ) and an internal rotor ( 150 ) according to claim 1 .

16. The internal rotor ( 150 ) according to claim 1 ,
wherein the extent of the second recess ( 231 ; 631 ) in tangential direction is at least 45% of the extent of the rotor magnet ( 221 ; 621 ) in tangential direction.

17. The internal rotor ( 150 ) according to claim 1 , wherein the clamping element ( 291 ; 691 ) has a first end section ( 291 L) and a second end section ( 291 R), which are each connected to a remaining area of the rotor plate ( 311 ), wherein a central section ( 291 M) is provided between the first end section ( 291 L) and the second end section ( 291 R).

18. The internal rotor ( 150 ) according to claim 17 , wherein, on the clamping element ( 291 ; 691 ), due to the tensioning toward the second recess ( 231 - 236 ; 631 ), in the central section ( 291 M) of the clamping element ( 291 ; 691 ), at least in sections on the side facing the rotor magnet ( 221 ), a compressive stress exists, and, on the side facing away from the rotor magnet ( 221 ), a tensile stress exists.

19. The internal rotor ( 150 ) according to claim 17 , wherein, on the clamping element ( 291 ; 691 ), due to the tensioning toward the second recess ( 231 - 236 ; 631 ), in the first end section ( 291 L) and in the second end section ( 291 R) of the clamping element ( 291 ; 691 ), a tensile stress exists on the side facing the rotor magnet ( 221 ), and a compressive stress exists on the side facing away from the rotor magnet ( 221 ).

20. The internal rotor ( 150 ) according to claim 17 , wherein, on the side facing the first recess ( 211 - 216 ; 611 ), the central section ( 291 M) is designed with convex curvature at least in sections.

21. The internal rotor ( 150 ) according to claim 17 ,
wherein, on the side facing the second recess ( 231 - 236 ; 631 ), the central section ( 291 M) is designed with concave curvature at least in sections.

22. The internal rotor ( 150 ) according to claim 17 ,
wherein the central section ( 291 M) has a protrusion ( 692 ) which protrudes into the first recess ( 211 - 216 ; 611 ).

23. An internal rotor ( 150 ) for an electric motor ( 100 ),
which internal rotor ( 150 ) has a laminated rotor core ( 200 ; 600 ) with a multiplicity of rotor plates ( 310

Assignees

• Ebm Papst St Georgen Gmbh & Co Kg

Inventors

• Schulde Arnold
• Herr Juergen
• Fehrenbach Johannes
• Flaig Markus
• Mayer Christoph
• Poyraz Serkan
• Radjenovic Bozidar

Classifications

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title

• H02K1/276 Primary

  Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] · CPC title