Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
  • H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
  • H01F41/12—Insulating of windings
  • H01F41/125—Other insulating structures; Insulating between coil and core, between different winding sections, around the coil
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/32—Insulating of coils, windings, or parts thereof
  • H01F27/324—Insulation between coil and core, between different winding sections, around the coil; Other insulation structures

Definitions

• the invention relates to electrical coils and transformer windings with a substantially rectangular winding cross-section and comprising a layer of flex ⁇ ible foil extending on the internal side and the end
• Such insulation devices are in particular used in transformer primary and/or secondary windings to perform an insulation barrier between the mains volt ⁇ age, e.g. 220V, and the user-touchable components of
• an insulation device is characterized in that the insulation layer is produced from a foil material which after being shaped to a tubular form corresponding to the external dimension of the actual winding is deformed to a substantially U-shaped cross-sectional profile corresponding to the winding cross-section.
• the U-shaped cross-sectional profile of the insulation device has according to an embodiment of the invention end portions with such a width that they project so much beyond the intended winding, thickness that they by the deformation effected after the winding may be bent in over the external side of the coil or the winding.
• Insulation devices produced according to the invention may in principle be used both for coreless coils and for any winding on a transformer of the type concerned, i.e. the primary winding or the secondary winding alone or both of them, and it may as well be used for each of the primary or secondary windings in a transformer with a number of primary and/or secondary windings.
• the obtained insulation barrier is appropriate in connection with windings disposed in standard as well as in special coil forms but may further be used with no coil form in that the winding is effected on a special mandrel and is supported by the encircling insulation barrier.
• the main advantage obtained by the invention is in particular an improved distribution between effect ⁇ ive copper area and insulated winding cross-section, which offers the possibility of reducing the trans ⁇ former dimensions or of lower operating temperatures. Owing to the possibility of increasing the effective coil width an improved coupling between the windings is obtained as a substantial advantage for the trans ⁇ former, which is in particular of importance as regards high-frequency pulse transformers of the switch-mode type.
• the invention further provides for a production ⁇ al relief because it is possible to a higher degree to avoid insulated supply lines through sufficient encap ⁇ sulation of the individual windings.
• the insulation material con ⁇ sists of a shrinkable material and the deformation to said U-shaped profile is effected by shrinking under thermal stress or other physical stress.
• shrink- able material may be available in the form of an extruded tubular blank (shrink-flex) or in the form of tape.
• Fig. 1 as an embodiment of the invention illus ⁇ trates a transformer with concentric primary and secon ⁇ dary windings
• Figs 2 to 4 illustrate the manufacture of the insulation device according to the invention
• Figs 5 and 6 illustrate the forming of an insul ⁇ ation layer in a tubular form in connection with a cir ⁇ cular and a square coil form
• Figs 7 to 11 show various examples of coil and transformer windings with an insulation device accord ⁇ ing to the invention.
• the primary winding 1 and the secondary winding 2 are disposed coaxially one over the other in a common coil form 3 so that the two windings in their full length overlap each other.
• the coil form 3 surrounds on its side an iron core 4.
• Each of the windings 1 and 2 consists in a known manner of a considerable number of turns of lacquered copper wire wound in such a manner that each of the windings is imparted a mainly rectangular wind ⁇ ing or copper cross-section.
• the primary winding 1 as well as the secondary winding 2 are provided with an insulation device according to the invention in the form of insulating layers 5 and 6 completely covering in the illustrated Example the internal side of each winding facing the core 4, and the end faces of the winding, and are further bent in over and cover at least part of the external side of the winding.
• the insulation layer is obtained in that a layer of foil material is firstly shaped to a tubular form 7 corresponding to the outer dimension of the end walls 8 of the coil form 3 or, if no coil form is used, the outer dimen ⁇ sion of the coil itself or the winding.
• the foil layer 7 shaped to a tubular form is subsequently deformed to a substantially U-shaped cross-sectional profile 7a as illustrated in Fig. 3, corresponding to the coil form 3 or, if no coil form is used, to the winding cross-section of the coil.
• the U-shaped cross-sectional profile is provided with end portions 7b, 7c with such a radial width that they project so much beyond the intended winding width that after winding they may be bent in over the external side of the coil or winding and cover a substantial part of or possibly the entire of this side.
• Producing the insulation layer with the tubular form 7 prior to deforming it to the U-shaped cross- sectional profile may be effected by cutting from a blank extruded in a tubular form a suitable insulation material or, as illustrated in Figs 5 and 6, by any other method that is more appropriate for a practical production in that the coil form 10, 10' is wound with a webshaped insulation material 9, 9' to constitute the tubular form 7.
• the insulation material is a shrinkable material and the deformation to the U-shaped cross-sectional profile is effected by a shrinking process, preferably by controlled thermal stress.
• insulation devices 11 and 12 are thus arranged both around the primary winding 13 and the secondary wind ⁇ ing 14 in such a manner that they cover the internal sides and end faces of both windings and further cover part of the external sides of the windings.
• Figs 8 and 9 show designs in which only the primary winding 13' and the secondary winding 14', respectively, have an insulation device 11' and 12', respectively, designed in the same manner as in Fig. 7.
• Fig. 10 illustrates an embodiment in which an insulation device 15 around a primary winding 16 completely encapsulates the winding also on its external side.
• Fig. 11 illustrates an insulation device 17 encapsulating a single coil winding 18.
• Figs 12 and 13 illustrate alternative embodi ⁇ ments forming for each of the illustrated primary and secondary windings 19, 19' and 20, 20', respective ⁇ ly, two separate insulation layers each from their respective foil material shaped to a tubular form as described in the foregoing and afterwards deformed to a substantially L-shaped cross-section covering part of the internal side of the winding and one end face thereof and of which an end portion is folded in over part of the external side of the winding.
• in the embodiment in Fig. 12 there are in this manner for each of the windings 19 and 20 provided two separate insulation devices 21, 22 and 23, 24, respectively, covering only end portions of the wind ⁇ ings
• each of the windings 10' and 20' provided two separate insulation devices 25, 26 and 27, 28 overlapping each other on the internal side of the winding.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Insulating Of Coils (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=8089978

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (3)

Family Cites Families (1)

• 1992
  • 1992-01-31 DK DK12092A patent/DK169799B1/da not_active IP Right Cessation
• 1993
  • 1993-01-28 DE DE69313671T patent/DE69313671D1/de not_active Expired - Lifetime
  • 1993-01-28 WO PCT/DK1993/000031 patent/WO1993015516A1/fr not_active Ceased
  • 1993-01-28 EP EP93903857A patent/EP0724765B1/fr not_active Expired - Lifetime
  • 1993-01-28 AU AU34923/93A patent/AU3492393A/en not_active Abandoned

Non-Patent Citations (1)

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