A MOLDED COIL

• US 3,711,807 A
• Filed: 07/12/1970
• Issued: 01/16/1973
• Est. Priority Date: 07/12/1970
• Status: Expired due to Term

• Current Assignee: Harutoki Nakamura, Kazuo Yamashita, Koichi Hirakawa
• Original Assignee: Harutoki Nakamura, Kazuo Yamashita, Koichi Hirakawa
• Inventors: Nakamura, Harutoki, Yamashita, Kazuo, Hirakawa, Koichi
• Primary Examiner(s): Goldberg, E. A.
• Application Number:
  US05/064,844
• Time in Patent Office: 919 Days
• Field of Search: 336/205,206,96 174/121R,25R 317/258
• US Class Current: 336/205
• CPC Class Codes: H01F 27/323 Insulation between winding turns, between winding layers
• CPC Class Codes: H01F 27/327 Encapsulating or impregnating encapsulating coil and core H01F27/022
• CPC Class Codes: H01F 41/127 Encapsulating or impregnating encapsulating coil and core H01F41/005

Abstract

A mold transformer consisting of a blank coil impregnated with an electrical insulating resin composition of epoxy resin or the like, said blank coil having as an insulator a highly impregnable non-woven polyester fabric or non-woven glass fabric interposed between a high-voltage winding and a low-voltage winding, between the high voltage winding and a magnetic core and between the lowvoltage winding and the magnetic core respectively, and a nonwoven polyester fabric between adjacent winding layers of each of the high-voltage and low-voltage windings; and a method of producing said mold transformer.

Claims

2. A molded transformer comprising a coil having a highly impregnable, heat-stable non-woven fabric interposed between a high-voltage winding and a low-voltage winding, between the high-voltage winding and a magnetic core and between the low-voltage winding and the magnetic core as insulators and non-woven polyester fabrics interposed between adjacent layers of the windings of both the high-voltage winding and the low-voltage winding as interlayer insulators to form a blank coil, said blank coil being impregnated with an electrically insulating resin composition such as an epoxy resin, wherein each of the interlayer insulators has a strip of an insulating material of a desired thickness placed on each of its extended ends lying in parallel with the winding direction, said insulators and insulating material being heated and pressed to be fused together.

3. A molded transformer comprising a coil having a highly impregnable, heat-stable non-woven fabric interposed between a high-voltage winding and a low-voltage winding, between the high-voltage winding and a magnetic core and between the low-voltage winding and the magnetic core as insulators and non-woven polyester fabrics interposed between adjacent layers of the windings of both the high-voltage winding and the low-voltage winding as interlayer insulators to form a blank coil, said blank coil being impregnated with an electrically insulating resin composition such as an epoxy resin, wherein each of the interlayer insulators has its extended ends lying in parallel with the winding direction folded at least once and each of the folded portions is sewed together by a thread of nylon, polyester or the like material.

4. A molded transformer comprising a coil having a highly impregnable, heat-stable non-woven fabric interposed between a high-voltage winding and a low-voltage winding, between the high-voltage winding and a magnetic core and between the low-voltage winding and the magnetic core as insulators and non-woven polyester fabrics interposed between adjacent layers of the windings of both the high-voltage winding and the low-voltage winding as interlayer insulators to form a blank coil, said blank coil being impregnated with an electrically insulating resin composition such as an epoxy resin, wherein each of the interlayer insulators has its extended ends lying in parallel with the winding direction folded at least once with a thread of nylon, polyester or the like material disposed therewithin, each of the folded portions being sewed together by a thread of nylon, polyester or the like material.

5. A molded transformer comprising a coil having a highly impregnable, heat-stable non-woven fabric interposed between a high-voltage winding and a low-voltage winding, between the high-voltage winding and a magnetic core and between the low-voltage winding and the magnetic core as insulators and non-woven polyester fabrics interposed between adjacent layers of the windings of both the high-voltage winding and the low-voltage winding as interlayer insulators to form a blank coil, said blank coil being impregnated with an electrically insulating resin composition such as an epoxy resin, wherein each of the interlayer insulators has its extended ends lying in parallel with the winding direction folded once or several times, each of the folded portions being applied with a liquid or a powder by an immersing or spray method which liquid or powder comprises an epoxy resin and a hardening agent heated to obtain a semi-cured state (a state of B-stage) of said epoxy resin.

6. A molded transformer comprising a coil having a highly impregnable, heat-stable non-woven fabric interposed between a high-voltage winding and a low-voltage winding, between the high-voltage winding and a magnetic core and between the low-voltage winding and the magnetic core as insulators and non-woven polyester fabrics interposed between adjacent layers of the windings of both the high-voltage winding and the low-voltage winding as interlayer insulators tO form a blank coil, said blank coil being impregnated with an electrically insulating resin composition such as an epoxy resin, wherein each of the interlayer insulators has its extended ends lying in parallel with the winding direction folded once or several times, and each of the folded portions is sewed together by a thread of nylon, polyester or the like material, applied with a liquid or a powder by an immersing or spray method which liquid or powder comprises an epoxy resin and a hardening agent heated to obtain a semi-cured state (a state of B-stage) of said epoxy resin.

7. A molded transformer comprising a coil having a highly impregnable, heat-stable non-woven fabric interposed between a high-voltage winding and a low-voltage winding, between the high-voltage winding and a magnetic core and between the low-voltage winding and the magnetic core as insulators and non-woven polyester fabrics interposed between adjacent layers of the windings of both the high-voltage winding and the low-voltage winding as interlayer insulators to form a blank coil, said blank coil being impregnated with an electrically insulating resin composition such as an epoxy resin, wherein each of the interlayer insulators has each of its extended ends lying in parallel with the winding direction stitched with a thread having a diameter and strength sufficient to prevent slipping out of the wound wires.