Radial magnetic bearing and method of manufacture

• US 9,845,829 B2
• Filed: 10/17/2014
• Issued: 12/19/2017
• Est. Priority Date: 10/17/2013
• Status: Active Grant

• Current Assignee: ABet SKF, SKF Magnetic Mechatronics, SAS (ABet SKF)
• Original Assignee: SKF Magnetic Mechatronics, SAS (ABet SKF)
• Inventors: Hay, Stephane, Soulier, Nicolas
• Primary Examiner(s): DESAI, NAISHADH N
• Application Number:
  US14/517,770
• Publication Number:
  US 20150137643A1
• Time in Patent Office: 1,159 Days
• Field of Search: 310 905, 310 90
• CPC Class Codes: B23P 15/003 bearings see also F16C33/00
• CPC Class Codes: F16C 2202/42 soft-magnetic, ferromagnetic
• CPC Class Codes: F16C 2300/02 General use or purpose, i.e. no use, purpose, special adaptation or modification indicated or a wide variety of uses mentioned
• CPC Class Codes: F16C 32/0461 of stationary parts of the magnetic circuit
• CPC Class Codes: F16C 32/0468 of moving parts of the magnetic circuit, e.g. of the rotor
• CPC Class Codes: F16C 32/0474 for rotary movement
• CPC Class Codes: F16C 32/048 with active support of two degrees of freedom, e.g. radial magnetic bearings
• CPC Class Codes: F16C 43/00 Assembling bearings
• CPC Class Codes: F16C 43/04 Assembling rolling-contact bearings
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine

Abstract

A radial magnetic bearing having an inner rotor including a central shaft having a ferromagnetic armature mounted on the shaft and an outer stator providing a plurality of electromagnets including poles made of ferromagnetic material which project radially inwardly towards the rotor is provided. As such, air-gaps (e) are left between end faces of the poles and the ferromagnetic armature, and coils wound around the poles. The poles are extended through outer portions attached to a supporting member. Each pole and the corresponding outer portion are included in an angularly segmented module providing a stack of laminations made of ferromagnetic material. The outer portion defines shoulders with respect to the corresponding pole, the outer portion contacting outer portions of neighboring segmented modules and the outer portions of all segmented modules being assembled by clamping rings, wherein the coils located in free spaces around the poles are mounted in a string.

Claims

1. A radial magnetic bearing, comprising:

an inner rotor having an axis of rotation and including a central shaft having an outer periphery and a ferromagnetic armature mounted on the shaft on outer periphery; and

an outer stator having a plurality of electromagnets including poles made of at least one of a ferromagnetic and stainless ferromagnetic material that project radially inwardly towards the rotor, leaving air-gaps (e) between end faces of the poles and the ferromagnetic armature, and

coils wound around the poles, the poles being extended through outer portions attached to a supporting member, wherein

each pole and the corresponding outer portion are included in an angularly segmented module having a stack of laminations made of at least one of a ferromagnetic and stainless ferromagnetic material, the outer portion defining shoulders with respect to the pole, the outer portion contacting outer portions of neighboring segmented modules and the outer portions of all segmented modules being assembled by clamping rings, and wherein

coils located in free spaces around the poles are mounted in a string.

2. The radial magnetic bearing according to claim 1, wherein each outer portion of each segmented module has rounded outer corners.

3. The radial magnetic bearing according to claim 2, wherein each outer portion of each segmented module includes a central hole provided in the stack of laminations for mounting purposes.

4. The radial magnetic bearing according to claim 3, wherein the clamping rings further comprise a first clamping ring having a plurality of holes designed to be registered with the central holes of the segmented modules and a second clamping ring having a plurality of guides designed for receiving the central holes of the segmented modules and the plurality of holes of the first clamping ring.

5. The radial magnetic bearing according to claim 4, wherein the angularly segmented modules all have the same shape.

6. The radial magnetic bearing according to claim 4, wherein the angularly segmented modules have the same radial size but have different sizes in a peripheral direction of the angularly segmented modules.

7. The radial magnetic bearing according to claim 4, wherein the poles of the angularly segmented modules further comprise a first number of pairs of poles of reduced width of a first set of angularly segmented modules and a second number of poles of larger width of a second set of angularly segmented modules which are disposed between the pairs of poles of reduced width.

8. The radial magnetic bearing according to any claim 7, wherein the number of the angularly segmented modules and of the corresponding poles is equal to one of 12, 16 and 20.

9. The radial magnetic bearing according to claim 7, wherein the number of pairs of poles of reduced width of the first set of angularly segmented modules is equal to four and the number of the poles of larger width of the second set of angularly segmented modules disposed between the pairs of poles of reduced width is equal to one of 1, 2 and 3.

10. The radial magnetic bearing according to claim 9, wherein the ferromagnetic armature of the inner rotor is made of a stack of high quality magnetic laminations.