	US 7,545,066 B2
	Jacketed active magnetic bearing
Luc Baudelocque, Vernon (France); Armand Lapierre, Fontaine Sous Jouy (France); Maurice Brunet, Sainte Colombe Pres Vernon (France); and Michel Lacour, Vernon (France)
Assigned to Societe de Mecanique Magnetique, Saint Marcel (France)
Filed on Feb. 23, 2007, as Appl. No. 11/709,957.
Claims priority of application No. 06 50671 (FR), filed on Feb. 27, 2006.
Prior Publication US 2007/0200443 A1, Aug. 30, 2007
Int. Cl. H02K 7/09 (2006.01)

U.S. Cl. 310—90.5 [310/104; 310/43; 310/45]

11 Claims

1. A jacketed active magnetic bearing for a rotary machine having a rotor in contact with a process gas and placed in a leaktight enclosure, the magnetic bearing comprising a bearing armature of laminated magnetic material secured to the rotor and placed inside said leaktight enclosure, a bearing stator made up of electromagnet windings associated with a yoke of laminated magnetic material that presents end pole pieces disposed at a short distance from said bearing armature but without making contact therewith, the bearing stator being disposed outside said leaktight enclosure, at least one position detector of the electromagnetic type comprising a detecter armature of laminated magnetic material mounted on the rotor inside the leaktight enclosure and a detector stator comprising electromagnet windings associated with a yoke of laminated magnetic material, the detector stator being disposed outside said leaktight enclosure, and electronic control circuits connected to said bearing electromagnet windings and to said detector electromagnet windings,

wherein the bearing stator is protected by a first jacket of magnetic anti-corrosion material which constitutes a portion of said leaktight enclosure and is secured to said bearing stator, wherein the detector stator is protected by a second jacket of non-magnetic anti-corrosion material that constitutes a portion of said leaktight enclosure and that is secured to said detector stator, wherein the first jacket is made of magnetic stainless steel of the 17/4 PH type, and wherein the second jacket is made of one of the materials constituted by a non-magnetic stainless steel of the AISI 304, 304L, 316, or 316L type, of Inconel, or of a superalloy.