# US 5,341,561 A · Process for producing the electric insulation of electric machine windings > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,341,561 A - Document ID: US5341561A - Status: Granted - Kind: A - Application number: 07/838,224 - Filed: 1992-04-08 - Granted: 1994-08-30 - Earliest claimed: 1990-07-03 - Assignees: Isovolta Osterreichische Isolierstoffwerke Aktiengesellschaft; CKD Trakce A.S. - Inventors: Josef Schorm; Otakar Zych; Gottfried Deutschmann - Web page: https://patentgrep.com/patent/US5341561A ## CPC - H02K 3/32: Windings characterised by the shape, form or construction of the insulation - H02K 15/12: Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines - Y10T 29/49009: Dynamoelectric machine - Y10T 29/49012: Rotor - Y10T 29/49073: by assembling coil and core - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract In order to produce the electric insulation of the winding of an electric machine, grooves having a cross-section that tapers at least in an area near to the groove opening are arranged in the rotor or motor. Before the winding is laid in the grooves, the latter are lined with a laminate that contains an elastically compressed mass of high-elastic, electrically insulating fibres and a solidified, curable synthetic resin that can still be thermally softened, however, and that holds the mass of fibres in its compressed state. Once the winding is laid and the grooves are closed, the rotor or stator is subjected to a vacuum pressure impregnation, then cured. During the impregnation process, the hot saturating resin penetrates into the pores of the elastically expandable laminate, elastically expanding the mass of fibres and filling the empty spaces in the grooves, so that the elastically expanded mass of fibres, that is supported at the surface of the groove, exerts on the upper subconductor bundle of the winding a force in the direction of the bottom of the grooves. ## Claims ### Claim 1 A process for manufacturing the electrical insulation of the winding of an electric machine, said machine having a rotor and a stator, each of which having radially directed grooves with groove openings, which has winding sections or subconductor bundles placed with play in the grooves of the rotor or stator comprising providing grooves whose cross-section proximate to the groove opening, tapers in a radial direction inwardly towards the groove opening, inserting at least in the area proximate to the groove opening, a laminate which expands under heating into the gap-shaped space which forms between the groove surface and the winding sections, this laminate containing an elastically compressible, highly elastic fiber material as well as a solidified, curable synthetic resin, which can, however, be thermally softened and which maintains the fiber material in its compressed state, heating the laminate in order to soften the synthetic resin, whereupon the laminate expands because of the released tension on the compressed fibers and fills out the aforementioned gap-shaped space such that, in said area of the tapering groove cross-section, the elastically expanding fiber material exerts at least on an inserted winding section or a subconductor bundle a considerable component of force in the direction of the bottom of the groove, and hardening the synthetic resin at an increased temperature. ### Claim 2 (depends on 1) The process of claim 1, wherein heating of the synthetic resin takes place via impregnation of the laminate with a hot liquid thermosetting material as an impregnation medium, which fills up the pores of the expanded laminate. ### Claim 3 (depends on 1) The process of claim 1, wherein prior to the expansion of the fiber material in the laminate used, the groove opening is closed by a temporary or permanent nib fixture. ### Claim 4 (depends on 3) The process of claim 3, further comprising applying a removable winding made of a temperature-contracting tape to the rotor surface to temporarily close the groove openings of the rotor. ### Claim 5 (depends on 2) The process of claim 2, wherein a removable, divisible, cylindrical template serves as a nib fixture to temporarily close the groove openings of a stator. ### Claim 6 (depends on 2) The process of claim 2, further comprising providing breech locks or backplates which are held in lateral mounting grooves in the side walls of the groove as permanent nib fixtures to close the groove openings. ### Claim 7 (depends on 1) The process of claim 1, wherein the area in which the groove cross-section tapers towards the groove opening or lies near the groove opening has a depth which is less than half the groove depth and that the upper edge of the winding section or subconductor bundle lying closest to the groove opening and facing the groove opening is located within this area. ### Claim 8 (depends on 1) The process of claim 1, wherein the laminate has a film of electrically insulating material on at least one side which is adjacent to the elastically expanding layer. ### Claim 9 (depends on 8) The process of claim 8, further comprising placing the laminate with the film side facing the groove wall in the gap-shaped space. ### Claim 10 (depends on 8) The process of claim 8, wherein the laminate has a film of electrically insulating material on both sides adjacent to the elastically expandable layer. ### Claim 11 (depends on 1) The process of claim 1, wherein the laminate has a film of electrically insulating material on both sides adjacent to the electrically expandable layers. ### Claim 12 (depends on 8) The process of claim 8, wherein the laminate contains at least one film consisting of polyester. ### Claim 13 (depends on 8) The process of claim 8, wherein the laminate contains at least one film consisting of polyimide or contains polyimide in a film compound. ### Claim 14 (depends on 1) The process of claim 1, wherein the fiber substance in the elastically expandable layer of the laminate consists at least predominantly of glass fibers. ### Claim 15 (depends on 1) The process of claim 1, wherein the fiber substance in the elastically expandable layer of the laminate consists at least predominantly of aramide fibers. ### Claim 16 (depends on 1) The process of claim 1, wherein the fiber substance in the elastically expandable layer of the laminate consists at least predominantly of polyester fibers. ### Claim 17 (depends on 1) The process of claim 1, wherein in the elastically expandable layer of the laminate, the fiber material is manufactured of fiber fleece, fiber mats, or fiber felts. ### Claim 18 (depends on 1) The process of claim 1, wherein the elastically expandable layer of the laminate has a synthetic resin content of 10 to 40% by weight. ### Claim 19 (depends on 18) Process of claim 18, wherein the elastically expandable layer of the laminate has a synthetic resin content of 10 to 28% by weight.