Internally damped stator, rotor, and transformer and a method of making

U.S. Cl. 29-596

10 Claims

US 6,499,209 B1 Internally damped stator, rotor, and transformer and a method of making Donald T. Landin, Eagan, Minn. (US); Gordon G. Johnson, Lake Elmo, Minn. (US); Jeffrey W. McCutcheon, Eagan, Minn. (US); and Larry S. Hilderbrand, Woodbury, Minn. (US) Assigned to 3M Innovative Properties Company, St. Paul, Minn. (US) Filed on Oct. 16, 2000, as Appl. No. 9/688,485. Application 09/688485 is a division of application No. 08/994496, filed on Dec. 19, 1997, granted, now 6191510. Int. Cl.7H02K 15/02 U.S. Cl. 298212;596 10 Claims 1. A method of making an internally damped core comprising the steps of: (a) providing a first laminate section and a second laminate section, wherein the first laminate section is formed by a method comprising the steps of (i) preparing a first laminate comprising a magnetic layer and a layer of vibration damping material bonded thereto; and (ii) cutting the first laminate section from the first laminate, the first laminate section having a shape; and wherein the second laminate section is formed by a method comprising the steps of (i) preparing a second laminate comprising (A) a first outer magnetic layer; (B) a second outer magnetic layer; and (C) a layer of vibration damping material positioned between the outer magnetic layers; (ii) cutting the second laminate section from the second laminate, wherein the second laminate section has shape which is substantially the same as the shape of the first laminate section, wherein the second magnetic layer of the second laminate section has a burr thereon caused by the cutting, (b) joining the first laminate section and the second laminate section to form a core in such a manner that the burr is not on the outside of the core; wherein the core is selected from the group consisting of stator cores, rotor cores and transformer cores.