Electric motor comprising an internal rotor and an external stator

Patent metadata

Field	Value
Publication number	US-9979246-B2
Application number	US-201414778911-A
Country	US
Kind code	B2
Filing date	Mar 19, 2014
Priority date	Mar 19, 2013
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

An electric motor ( 100 ) features a external stator ( 28 ), an internal rotor ( 150 ) rotatably mounted within the external stator, the rotor having a lamination stack ( 200, 200′, 200 ″) composed of a plurality of rotor plates ( 201, 201′, 201 ″) in which are formed at least one first recess ( 614 ) and at least one second recess ( 630 ), a rotor magnet ( 224 ) being located in each first recess ( 614 ), the second recess ( 630 ) being associated with a jamming element ( 40 ) mounted therein. A clamping member ( 692,694 ) is arranged between the first recess ( 614 ) and the second recess ( 630 ). The clamping member and the second recess ( 630 ) are shaped so as to enable support of the jamming element ( 40 ) on the lamination stack, and to permit application of a force (F) on the clamping member in the direction of the rotor magnet. The second recess ( 630 ) serves as a through-opening for receiving a shaft ( 40 ), and the shaft ( 40 ) serves as the jamming element ( 40 ).

First claim

What is claimed is:

1. An electric motor, comprising:
an external stator ( 28 );
an internal rotor ( 150 ), mounted for rotation within said external stator ( 28 ), having a lamination stack ( 200 ; 200 ′; 200 ″) composed of a plurality of rotor lamination plates ( 201 , 202 ; 201 ′, 201 ″) and in which at least one first cutout or pocket ( 614 ) and a second cutout ( 630 ) are formed, said first cutout or pocket ( 614 ) being associated with a rotor magnet ( 224 ) arranged therein;
said second cutout ( 630 ) being associated with a jamming element ( 40 ) arranged therein;
a clamping member ( 692 , 694 ) being arranged between the first cutout ( 614 ) and the second cutout ( 630 );
at least one predetermined amination plate ( 201 ; 201 ′; 201 ″) of the lamination stack ( 200 ; 200 ′; 200 ″) having, in order to form the clamping member ( 692 , 694 ), along the extent of the clamping member, on a first side, a first recess ( 671 ) at least partway along the clamping member ( 692 , 694 ) and, on a second side opposite said first side, a second recess ( 672 ) at least partway along the clamping member ( 692 - 694 ), said first recess ( 671 ) and second recess ( 672 ) extending outwardly from the second cutout ( 630 ), outside of said jamming element ( 40 ), said first recess ( 671 ) being open to the second cutout ( 630 ),
the jamming element ( 40 ) and the second cutout ( 630 ) being configured such that support of the jamming element ( 40 ) on the lamination stack ( 200 ; 200 ′; 200 ″) is enabled;
a force (F) is applied to the clamping member ( 692 , 694 ) in a direction toward the rotor magnets ( 224 ), so that the rotor magnets ( 224 ) are thereby clamped into said first cutout or pocket ( 614 );
the lamination stack ( 200 ; 200 ′; 200 ″) is formed with a through-passage ( 630 ) for receiving a shaft ( 40 ), said second cutout ( 630 ) serving as said through-passage ( 630 ); and
said shaft ( 40 ) serves as said jamming element ( 40 ).

2. The electric motor according to claim 1 , wherein
the clamping member ( 692 , 694 ) is shaped so as to enable a radially outwardly directed displacement of the clamping member ( 694 ) by the jamming element ( 40 ).

3. The electric motor according to claim 1 , wherein
the rotor magnet ( 224 ) has a radially inner surface and wherein the clamping member ( 692 , 694 ) is shaped so that it clamps the rotor magnet ( 224 ) into the first pocket ( 614 ) only at a portion of said radially inner surface.

4. The electric motor according to claim 1 , wherein
the jamming element ( 40 ) is composed of a harder material than that of the lamination stack ( 200 ; 200 ′; 200 ″).

5. The electric motor according to claim 1 , wherein
the jamming element ( 40 ) is formed with a taper ( 45 ), in order to facilitate introduction into said second cutout ( 630 ).

6. The electric motor according to claim 1 , wherein the clamping member ( 692 , 694 ) has a projection ( 684 ) directed toward said second cutout ( 630 ).

7. The electric motor according to claim 1 , wherein the clamping member ( 694 ) extends from the second cutout ( 630 ) to the first cutout or pocket ( 614 ).

8. The electric motor of claim 1 , wherein said first and second recesses ( 671 , 672 ) run parallel to each other, at least partway along.

9. The electric motor of claim 1 , wherein said first and second recesses ( 671 , 672 ) run radially.

10. The electric motor of claim 1 , wherein the first and second recesses ( 671 , 672 ) each run so curvingly from a region between the first cutout ( 614 ) and the second cutout ( 630 ), to the first cutout ( 614 ) and to the second cutout ( 630 ), that they ( 671 , 672 ), at least in part, approach toward each other.

11. The electric motor according to claim 1 , wherein
said first and second recesses ( 671 , 672 ) are each T-shaped at their radially outer portions.

12. The electric motor of claim 1 , wherein a third recess ( 675 ) is provided, which extends from said first cutout ( 614 ) inwardly.

13. The electric motor of claim 12 , wherein the third recess ( 675 ) has a first portion ( 676 ) which is elongated and which extends from said first cutout ( 614 ) in a radially inward direction.

14. The electric motor of claim 13 , wherein the third recess ( 675 ) is formed, at an inner end of said first portion ( 676 ), with a second portion ( 677 ) which is wider than said first portion ( 676 ).

15. The electric motor according to claim 12 , wherein a maximum outward radial extent ( 911 ) of the first recess ( 671 ) has a first spacing from the rotation axis;
a maximum outward radial extent of the second recess ( 672 ) has a second spacing from the rotation axis; and
a maximum inward radial extent of the third recess ( 675 ) has a third spacing from the rotation axis; and
said first spacing and said second spacing are each larger than said third spacing.

16. The electric motor according to claim 12 , wherein
the rotor plate ( 201 ′), in a region between the first cutout ( 614 ) and the second cutout ( 630 ), has a meandering course ( 654 ).

17. The electric motor according to claim 1 , wherein
a clamping member ( 692 , 694 ) is connected, at its end adjacent the first cutout ( 614 ), via at least one bridge ( 621 ) with remaining portions of the respective rotor lamination plate ( 201 , 201 ′, 201 ″) and wherein the first recess ( 671 ) or the second recess ( 672 ) have, adjacent said at least one bridge ( 621 ), an angled-away portion ( 671 ′, 672 ′).

18. The electric motor according to claim 1 , wherein
the clamping member ( 692 , 694 ) is connected, at its end adjacent the second cutout ( 630 ), via at least one bridge ( 622 ) with remaining portions of the respective rotor lamination plate ( 201 , 201 ′, 201 ″) and wherein the first recess ( 671 ) or the second recess ( 672 ) have, adjacent said at least one bridge ( 622 ), an angled-away portion ( 671 ′, 672 ′).

19. The electric motor according to claim 1 , wherein a predetermined rotor plate ( 201 , 201 ′, 201 ″) has a number N of first pockets ( 614 ) for receiving a number N of rotor magnets ( 220 ) and wherein the predetermined rotor plate ( 201 , 201 ′, 201 ″) has a number K of clamping members ( 692 , 694 ), with N being equal to K.

20. The electric motor according to claim 1 , having at least two predetermined rotor plates ( 201 , 201 ′, 201 ″) which each have a number N of first pockets ( 614 ) for receiving a number N of rotor magnets ( 220 ),
and wherein a number K of clamping members ( 692 , 694 ) are provided, where N is greater than 1, and
where K has a value which falls in the range from 1 to N−1.

21. An electric motor, comprising:
an external stator ( 28 );
an internal rotor ( 150 ), mounted for rotation within said external stator ( 28 ), having a lamination stack ( 200 ; 200 ′; 200 ″) composed of a plurality of rotor lamination plates ( 201 , 202 ; 201 ′, 201 ″) and in which at least one first cutout or pocket ( 614 ) and one second cutout ( 630 ) are formed;
said first cutout or pocket ( 614 ) being associated with a rotor magnet ( 224 ) arranged therein;
said second cutout ( 630 ) being associated with a jamming element ( 40 ) arranged therein;
a clamping member ( 692 , 694 ) being arranged between the first cutout ( 614 ) and the second cutout ( 630 );
at least one predetermined lamination plate ( 201 ; 201 ′; 201 ″) of the lamination stack ( 200 ; 200 ′; 200 ″) having, in order to form the clamping mem

Assignees

• Ebm Papst St Georgen Gmbh & Co Kg
• Emb Papst St Georgen Gmbh & Co Kg

Inventors

• Helbling Sergej

Classifications

• H02K29/03

  with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems · CPC title

• H02K1/30 Primary

  using intermediate parts, e.g. spiders · CPC title

• H02K1/276 Primary

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