Rotor for an electrical machine

Patent metadata

Field	Value
Publication number	US-9467014-B2
Application number	US-201415022195-A
Country	US
Kind code	B2
Filing date	Sep 26, 2014
Priority date	Sep 27, 2013
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

The present application relates to a rotor ( 1 ) for an electrical machine. The rotor ( 1 ) comprises at least one substantially cylindrically shaped ferromagnetic base element ( 2 ). Said ferromagnetic base element ( 2 ) includes a multitude of posts ( 3, 3.1, 3.2 ) radially extending therefrom, each of said posts ( 3, 3.1, 3.2 ) being bordered by at least a first lateral surface ( 4 ) and a second lateral surface ( 5 ), wherein recesses ( 7 ) are defined between each pair of neighbouring posts ( 3, 3.1, 3.2 ). One ferromagnetic intermediate member ( 13 ) is arranged in each recess ( 7 ) between each pair of posts ( 3, 3.1, 3.2 ). Each ferromagnetic intermediate member ( 13 ) is affixed to the first lateral surface ( 4 ) of a first post ( 3.1 ) and to the second lateral surface ( 5 ) of a second post ( 3.2 ) of each pair of posts ( 3, 3.1, 3.2 ) by means of at least one permanent magnet ( 6, 6.1, 6.2 ), respectively, said permanent magnets ( 6, 6.1, 6.2 ) being each oriented such that the same pole faces said ferromagnetic intermediate members ( 13 ). The first lateral surface ( 4 ) and said second lateral surface ( 5 ) are shaped such that the distance between the first lateral surface ( 4 ) and the second lateral surface ( 5 ) decreases with increasing distance from the rotation axis ( 11 ) of the rotor ( 1 ) in a radial direction and an inner surface ( 15 ) of each ferromagnetic intermediate member ( 13 ) is facing towards the rotor axis ( 11 ) and is covered with at least one additional permanent magnet ( 20.1, 20.2, 20.3 ). At least one additional permanent magnet ( 20.1, 20.2, 20.3 ) is arranged such that the pole oriented towards the ferromagnetic intermediate members ( 13 ) and is the same pole as the pole of the permanent magnets ( 6, 6.1, 6.2 ) oriented towards said ferromagnetic intermediate members ( 13 ).

First claim

The invention claimed is:

1. Rotor for an electrical machine comprising at least one substantially cylindrically shaped ferromagnetic base element ( 2 ), said ferromagnetic base element ( 2 ) including a multitude of posts ( 3 , 3 . 1 , 3 . 2 ) radially extending therefrom, each of said posts ( 3 , 3 . 1 , 3 . 2 ) being bordered by at least a first lateral surface ( 4 ) and a second lateral surface ( 5 ), wherein recesses ( 7 ) are defined between each pair of neighbouring posts ( 3 , 3 . 1 , 3 . 2 ), one ferromagnetic intermediate member ( 13 ) is arranged in each recess ( 7 ) between each pair of posts ( 3 , 3 . 1 , 3 . 2 ), characterized in that each ferromagnetic intermediate member ( 13 ) is affixed to the first lateral surface ( 4 ) of a first post ( 3 . 1 ) and to the second lateral surface ( 5 ) of a second post ( 3 . 2 ) of each pair of posts ( 3 , 3 . 1 , 3 . 2 ) by means of at least one permanent magnet ( 6 , 6 . 1 , 6 . 2 ), respectively, said permanent magnets ( 6 , 6 . 1 , 6 . 2 ) being each oriented such that the same pole faces said ferromagnetic intermediate members ( 13 ) wherein said first lateral surface ( 4 ) and said second lateral surface ( 5 ) are shaped such that the distance between the first lateral surface ( 4 ) and the second lateral surface ( 5 ) decreases with increasing distance from the rotation axis ( 11 ) of the rotor ( 1 ) in a radial direction and in that an inner surface ( 15 ) of each ferromagnetic intermediate member ( 13 ) facing towards the rotor axis ( 11 ) is covered with at least one additional permanent magnet ( 20 . 1 , 20 . 2 , 20 . 3 ), said at least one additional permanent magnet ( 20 . 1 , 20 . 2 , 20 . 3 ) being arranged such that the pole oriented towards the ferromagnetic intermediate members ( 13 ) is the same pole as the pole of the permanent magnets ( 6 , 6 . 1 , 6 . 2 ) oriented towards said ferromagnetic intermediate members ( 13 ).

2. Rotor according to claim 1 , wherein said permanent magnets ( 6 , 6 . 1 , 6 . 2 ) have opposing north and south magnetic poles and said permanent magnets being each oriented such that the magnetic poles facing one of said ferromagnetic intermediate members ( 13 ) are the same.

3. Rotor according to claim 1 , wherein each ferromagnetic intermediate member ( 13 ) is affixed to a bottom surface ( 71 ) of the recess ( 7 ) by means of at least one rotation locking permanent magnet ( 60 . 1 , 60 . 2 ), said at least one rotation locking permanent magnets ( 60 . 1 , 60 . 2 ) being each oriented such that the same pole faces said ferromagnetic intermediate members ( 13 ).

4. Rotor according to claim 3 , wherein the at least one rotation locking permanent magnet ( 60 . 1 , 60 . 2 ) has a distal surface abutting the intermediate member ( 13 ) and a proximal surface abutting the bottom surface ( 71 ) of the recess ( 7 ).

5. Rotor according to claim 3 , wherein the at least one rotation locking permanent magnet ( 60 . 1 , 60 . 2 ) having the distal surface abutting the intermediate member ( 13 ) and the proximal surface abutting the bottom surface ( 71 ) of the recess ( 7 ) has dimensions sufficiently large to lock the rotation of the intermediate member ( 13 ).

6. Rotor according to claim 3 , wherein the rotor comprises at least two rotation locking permanent magnets ( 60 . 1 , 60 . 2 ) having distal surfaces abutting the intermediate member ( 13 ) and proximal surfaces abutting the bottom surface ( 71 ) of the recess ( 7 ) and that the ferromagnetic intermediate member ( 13 ) is affixed to the first lateral surface ( 4 ) of a first post ( 3 . 1 ) and to the second lateral surface ( 5 ) of a second post ( 3 . 2 ) of each pair of posts ( 3 , 3 . 1 , 3 . 2 ) by means of at least one permanent magnet ( 6 , 6 . 1 , 6 . 2 ), respectively, said permanent magnets ( 6 , 6 . 1 , 6 . 2 ) being each oriented such that the same pole faces said ferromagnetic intermediate members ( 13 ) and is further affixed to said bottom surface ( 71 ) of said recess by said at least two additional permanent magnets, said intermediate member ( 13 ) thereby being affixed to said ferromagnetic base element ( 2 ) in at least for different fixing points, said fixing point being defined by a permanent magnet fixed between said ferromagnetic base member ( 2 ) and said ferromagnetic intermediate member ( 13 ).

7. Rotor according to claim 1 , wherein said first and second lateral surface permanent magnets ( 6 , 6 . 1 , 6 . 2 ) have opposing north and south magnetic poles and said permanent magnets being each oriented such that the magnetic poles facing one of said ferromagnetic intermediate members ( 13 ) are the same.

8. Rotor according to claim 1 , wherein said first lateral surface ( 4 ) and said second lateral surface ( 5 ) of said posts ( 3 , 3 . 1 , 3 . 2 ) and/or a first surface ( 8 ) and a second surface ( 9 ) of the ferromagnetic intermediate members ( 13 ) facing said first lateral surface ( 4 ) and said second lateral surface ( 5 ) comprise at least one form-fit connection element ( 16 , 17 ) allowing a form-fit connection with said at least one permanent magnet ( 6 , 6 . 1 , 6 . 2 ), said form-fit connection element ( 6 , 7 ).

9. Rotor according to claim 8 , wherein said at least one permanent magnet ( 6 , 6 . 1 , 6 . 2 ) is fastened to said first lateral surface ( 4 ) and said second lateral surface ( 5 ) and/or to said first surface ( 8 ) or said second surface ( 9 ) of the ferromagnetic intermediate member ( 13 ) facing said first lateral surface ( 4 ) and said second lateral surface ( 5 ) by means of an adhesive.

10. Rotor according to claim 1 , wherein said rotor ( 1 ) comprises a multitude of ferromagnetic base elements ( 2 ) stacked one upon the other in the axial direction of the rotor ( 1 ).

11. Rotor according to claim 10 , wherein an intermediate spacer plate ( 18 ) is arranged between each of two neighbouring ferromagnetic base elements ( 2 ), said intermediate spacer plate ( 18 ) comprising radial air ducts.

12. Rotor according to any of claim 10 , wherein neighbouring ferromagnetic base elements ( 2 ) are shifted angularly to each other in the axial direction.

13. Rotor according to claim 1 , wherein at least one non-magnetic support member ( 19 , 19 . 1 , 19 . 2 ) is arranged in each gap ( 12 ) formed between the inner surface ( 15 ) of each ferromagnetic intermediate member ( 13 ) facing towards the rotor axis ( 11 ) and the ferromagnetic base element ( 2 ).

14. Rotor according to claim 1 , wherein said ferromagnetic intermediate members ( 13 ) are made of a plurality of stacked sheets of magnetic steel.

15. Rotor according to claim 1 , wherein said at least one ferromagnetic base element ( 2 ) is arranged on a shaft ( 10 ) and attached thereto by an adhesive shrink-fit connection.

Assignees

• Smidth As F L

Inventors

• Gotschmann Norbert
• Rittler Stefan

Classifications

• H02K1/2766 Primary

  having a flux concentration effect · CPC title

• H02K21/046

  with rotating permanent magnets and stationary field winding · CPC title

• H02K1/28

  Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures · CPC title

• H02K1/2746 Primary

  the rotor consisting of magnets arranged with the same polarity, e.g. consequent pole type · CPC title