Electrically insulated electric conductor strip, in particular for electric motors and transformers

Abstract

An electrically insulated electrical conductive strip (1), especially for electric motors and transformers, having an electrical conductor (2) in strip form that has an upper face (2a) and a lower face (2b), two lateral edge faces (2c) and one end edge face at each end, and having an electrical insulation (3) disposed on at least one face of the strip (2a, 2b). The insulation (3) has an enamel layer (3a) and an adhesive strip (3b) bonded to the lower face (2b) and/or the upper face (2a) of the electrical conductor (2) in strip form, in each case at least in a region (4) that directly adjoins a lateral edge face (2c).

Claims

1. An electrically insulated electrical conductive strip, adapted for use in machines and devices including electric motors and transformers comprising, an electrical conductor in a strip form that has an upper face and a lower face, two lateral edge faces and one end edge face at each end, and an electrical insulation disposed on at least one of the faces of the strip, wherein the insulation comprises an enamel layer and an adhesive strip bonded to the lower face or the upper face of the electrical conductor in a strip form, at least in a region of the upper or lower face that directly adjoins one of the lateral edge faces, such that the insulation bordering on the region with the adhesive strip is exclusively formed by the enamel layer; wherein the enamel layer is formed from an enamel based on a THEIC-modified polyesterimide, the enamel layer having a thickness in the range from 5 m to 50 m; wherein the adhesive strip has a thickness in the range from 3 m to 20 m, and the thickness is at least half the thickness of the enamel layer in a region where there is no adhesive strip.

2. The conductive strip according to claim 1 further comprising, the adhesive strip is bonded in a C shape around one of the lateral edge faces proceeding from the upper and the lower faces.

3. The conductive strip according to claim 1 further comprising, the adhesive strip has an excess with respect to one of the lateral edge faces of the electrical conductor in strip form having a length less than or equal to 5 cm.

4. The conductive strip according to claim 1 further comprising, the electrical conductor in strip form consists of aluminium or of an aluminium alloy and has a thickness in the range from 0.1 mm to 1.5 mm.

5. The conductive strip according to claim 1 further comprising, the enamel layer is formed above or beneath the adhesive strip.

6. The conductive strip according to 1 further comprising, a region of the adhesive strip directly adjacent to one of the lateral edge faces of the electrical conductor in strip form has a width in the range from 0.2 cm to 4.5 cm.

7. The conductive strip according to claim 1 further comprising, a region of the adhesive strip directly adjacent to one of the lateral edge faces of the electrical conductor in strip form has a width in the range from 0.5 to 1.5 cm.

8. The conductive strip according to claim 1 further comprising, the insulation is disposed on both the upper and the lower face.

Description

DESCRIPTION OF THE DRAWINGS

(1) The invention is elucidated in detail by an example illustrated by the appended drawing.

(2) FIG. 1 shows, in a schematic diagram, a conductive strip of the invention.

(3) FIGS. 2 to 7 show variants of the conductive strip of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(4) With regard to the description that follows, it is explicitly emphasized that the invention is not limited to the example, nor is it limited to all or multiple features of combinations of features described. Instead, any individual component feature of the example may be of inventive significance on its own, and also in combination with other component features, even in isolation from all other component features described in connection therewith. FIGS. 2 to 7 identify identical parts of the conductive strip by the same reference numerals.

(5) The inventive conductive strip 1 shown in FIG. 1 comprises an electrical conductor 2 in strip form that has an upper face 2a and a lower face 2b, two lateral edge faces 2c and an end edge face at each end (not shown). In addition, the inventive conductive strip 1 comprises an electrical insulation 3 applied on at least one side of the strip 1; in the embodiment shown, both to the lower face 2b and to the upper face 2a.

(6) The insulation comprises an enamel layer 3a and an adhesive strip 3b, especially a film adhesive strip, consisting of plastic and bonded to the lower face 2b and/or the upper face 2a of the electrical conductor 2 in strip form, in each case at least in a region 4 directly adjoining a lateral edge face 2c.

(7) The adhesive strip 3b has an excess 5 with respect to the lateral edge face 2c of the electrical conductor 1 in strip form, which can prevent stray currents. The excess 5 may preferably have a length L in the range of 0 cm<L5 cm.

(8) The electrical conductor 2 in strip form may especially consist of aluminium or of an aluminium alloy and preferably have a thickness D in the range from 0.1 mm to 1.5 mm.

(9) The enamel of the enamel layer 3a, which can be applied by dipping, as by electrocoating, or by brush application, roll application, spin-coating, spraying, especially in a continuous belt method, and then cured, has the effect that at least the lower face 2b and/or the upper face 2a has adequate electrical insulation.

(10) The enamel layer 3a may be formed here from an enamel based on organic polymers, as of an acrylic enamel, epoxy enamel, polyester enamel, polyamide enamel or fluoropolymer enamel, or be based on sol-gel compositions, especially of a wire enamel such as a THEIC-modified polyesterimide. It may preferably have a thickness DL in the range from 5 m to 50 m. As stated, in the region of the adhesive strip 3b, this thickness DL may also be smaller, especially in order to give rise to a flat surface O of the insulation 3.

(11) The adhesive strip 3b may preferably have a thickness DK in the range from 3 m to 20 m, where this thickness DK may preferably be at least half the thickness DL of the enamel layer 3a in the region where there is no adhesive strip 3b.

(12) The region 4 directly adjoining the lateral edge face 2c of the electrical conductor 2 in strip form may have a width B in the range from 0.2 cm to 4.5 cm, preferably in the range from 0.5 to 1.5 cm.

(13) FIGS. 2 to 7 show further embodiments.

(14) In FIG. 2, the two excesses 5 of the adhesive strips 3a, 3b applied at either end are bonded to one another by a glue.

(15) In FIG. 3, the adhesive strip 3b has been applied with the excess 5 only at one end, and the enamel layer 3a tapers like a meniscus on the adhesive strip 3b and ends before the excess 5. In this case, the lower face 2b and the respectively adjoining lateral edge face 2c has been provided with the enamel layer 3a, where the enamel layer 3a at the transition to the lateral edge face 2c and thereon may have such a thickness DL that, in itself, is insufficient for the required electrical insulation.

(16) FIG. 4 shows an alternative to FIG. 3, in which the face 2b and lateral edge face 2c each have no electrical insulation and especially no enamel layer 3a.

(17) FIG. 5 shows a variant in which the adhesive strip 3b is bonded in a C shape around the lateral edge face 2c proceeding from the two faces 2a, 2b by a cover section 3c. In this execution too, the enamel layer 3a ends like a meniscus on the adhesive strip 3a before commencement of the cover section 3c.

(18) FIG. 6 shows an alternative to FIG. 3. In this case, the enamel layer 3a has been applied only on one side of the upper face 2a and on the adhesive strip 3b up to the start of the cover section 3c.

(19) FIG. 7 shows a variant of FIG. 5. Here, the electrical conductor 2, in the region of its lateral edge face 2c, has a reduced strip thickness Di compared to the strip thickness D in the rest of the strip region. In this case, in particular, the reduction in strip thickness in the region of the faces 2a, 2b is the same and is less than/equal to the thickness DK of the adhesive strip 3b. The enamel layer 3a runs here continuously up to the cover section 3c.

(20) The person skilled in the art is also able to add further technical features without leaving the scope of the invention. For instance, the working example shows just one option for the lamination with the adhesive strip 3b. Alternatively, it is also possible to lay an adhesive strip 3b around the edge area 2c, or the enamel layer 3a could be beneath the adhesive strip 3b.

(21) While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.