WO2018215434A1

WO2018215434A1 - Spacer strip, transformer winding and transformer and the method for producing a spacer strip

Info

Publication number: WO2018215434A1
Application number: PCT/EP2018/063340
Authority: WO
Inventors: Martin Straus
Original assignee: Isotek Gmbh
Priority date: 2017-05-24
Filing date: 2018-05-22
Publication date: 2018-11-29
Also published as: DE102017208814A1

Abstract

The invention relates to a spacer strip (1) for a transformer having a strip-form carrier (10), which extends along a longitudinal axis (L), and a plurality of mounting locations (2) which are spaced apart from one another along the longitudinal axis (L) and at each of which a spacer element (20, 30, 40, 50, 60, 70) is arranged. In order to provide a spacer strip which avoids the disadvantages of the spacer strips known from the prior art, provision is made for the spacer elements (20, 30, 40, 50, 60, 70) to be fastened to the carrier (10) in a force-fitting and/or form-fitting manner.

Description

Spacer tape, transformer winding and transformer and the method for producing a spacer strip

description

The present invention relates to a spacer tape, a transformer winding and a transformer, and a method for producing a spacer tape.

Transformers generally have an iron core around which several electrical conductors are wound. The conductor windings form coils, by means of which an input AC voltage is transformed into an AC output voltage. The conductors can be wound in different ways. For example, a simple coil can be made from a single piece of wire by helically winding the wire about a central axis or around a core. In another winding method, a conductor has multiple conductor windings. Each conductor winding is spirally wound in a plane perpendicular to a central axis. The two ends of the conductor winding are connected to similar conductor windings in overlying and underlying planes along the core axis, forming a continuous conductor. This type of winding is also known as disc winding.

Generic spacer strips are used in the construction of large transformers or power transformers as spacers between two radially adjacent conductor windings or two turns of the same conductor winding. In this case, there should be a radial distance between the adjacent conductor windings or windings with respect to the diameter of the coil, by which the conductor windings are electrically isolated from each other and serve both as a cooling channel. When used as intended, air and / or water should be prevented from entering the transformer to prevent short circuits of the transformer. For this reason, transformers using corresponding spacer strips are completely under oil during operation. The oil also serves as an insulator and reduces the risk of short circuits.

In addition to the radial distance axial cooling channels are to be formed by means of the spacer strips, through which the oil can circulate. The oil absorbs heat in the areas between the conductor windings and dissipates them.

Generic spacers consist essentially of a band-shaped carrier, are arranged on the spacer elements, and are inserted together with the winding wire in the production process of the winding with. The spacer elements are spaced apart from one another along the carrier, whereby cooling ducts are formed between the spacer elements when used as intended in the transformer. Corresponding spacer bands are known, for example, from DE 1 938 987 or DE 28 13 01 1 C2. The spacer strips are usually made of pressboard, which is why they are impregnated by the oil. Soaking is desirable because it avoids trapped air.

In practice, glued or glued spacer strips are often used. DE 1 938 987 proposes, for the production of a spacer tape, to wind up a strip of insulating material pretreated with glue and to fasten it to a base strip. In the case of the spacer strip of DE 28 13 01 1 C2, by contrast, cuboidal or prism-shaped flow control elements are glued onto a strip. However, the use of glue or adhesive to attach spacers to the belt-shaped carrier can result in trapped air which, in turn, causes partial discharges in the windings can cause. Since these partial discharges can lead in the long term to a transformer to a total failure, it would therefore be desirable to be able to do without this type of connection.

Alternatively, the flow control elements and the band can also be made in one piece. DE 28 13 01 1 C2 proposes a corresponding spacer strip.

Although the use of adhesive or glue can be avoided by the one-piece production of carrier and spacer elements, such spacer strips are usually made of plastics. Although plastics are electrically insulating, they can not be soaked in oil. In addition, the use of plastics from an environmental point of view is disadvantageous. In addition, spacer strips with plastic elements can not be used in oil-cooled transformers, since small air bubbles form on the boundary layer between plastic and oil, which lead to partial discharges. Apart from that, spacer strips with plastic elements are considerably more costly than spacer strips made from pressed chip.

An alternative to the one-piece, plastic-based spacer bands is the spacer band known from EP 0 040 382 A1. There, a pressboard is provided on the top and bottom with grooves, creating a one-piece spacer strip with spacers, which are interconnected by webs, arises. However, this form of production is very complicated, especially when a high dimensional accuracy of the spacer elements is required. In addition, the spacer strip produced in this way does not have sufficient flexibility for co-winding with the conductors.

It is therefore the object of the invention to provide a spacer strip which avoids the disadvantages of the spacer strips known from the prior art. This object is achieved by a spacer strip according to claim 1, a transformer winding according to claim 20, a transformer according to claim 21 and a method according to claim 22.

The spacer strip according to the invention for a transformer has a band-shaped carrier extending along a longitudinal axis L and a plurality of spacer elements arranged at a distance from one another along the longitudinal axis L at mounting locations. The spacer strip is characterized in that the spacer elements are non-positively and / or positively secured to the carrier.

By a non-positive and / or positive connection of the carrier and spacer element, the use of adhesive is avoided, which is disadvantageous for the reasons mentioned above. In addition, non-positive and positive connections are easy to automate, whereby the production of the spacer strips can be simplified.

For the purposes of the present invention, positive engagement also preferably includes connections in which the connection partners can move relative to one another, as is the case, for example, in the case of a conventional round link chain.

It is therefore preferably provided that there is no material connection between the carrier and the spacer elements. In this way, the risk of pores in cohesive compounds can be completely bypassed.

Preferably, the spacer strip consists of the band-shaped carrier and the spacer elements. Other components are not required, which makes production and assembly much easier. Advantageously, the carrier and / or the spacer elements made of wood pulp and / or wood pulp, in particular from pressboard. Pressspan can be soaked in oil, whereby any pores in the carrier or the spacer elements are filled with oil by omitting adhesive. In this way the risk of partial discharges in the transformer is reduced. In addition, pulp and wood pulp are ecologically beneficial compared to plastics.

The carrier preferably has a carrier thickness TD with 0.1 mm <TD <1 mm, in particular 0.2 mm <TD <0.3 mm. A suitably designed carrier is sufficiently stable but does not wear too much.

In advantageous developments it is provided that at least one of the spacer elements has at least one groove in which the carrier is arranged. A groove can be produced in a simple manner and also automatically. In addition, a secure connection with the carrier can be realized by a groove in the spacer elements. Preferably, the groove is a clamping groove, a flat groove, a guide groove or a retaining groove.

It is preferably provided that at least one of the spacer elements has a perpendicular to the longitudinal axis L extending clamping groove in which a bead of the carrier is arranged. A bead is advantageous in that the carrier only needs to be deformed and not machined with parting or joining techniques. In particular, separation processes can have a negative influence on the structural stability of the support. These are avoided by forming a bead.

Advantageously, the carrier is divided into at least one of the mounting locations in at least three sub-webs, wherein at least one sub-web run on an upper side of the spacer element and at least two sub-webs on an underside of the spacer element opposite the upper side. To this Way, the spacer elements are received and held between the partial webs. Particularly preferably, an odd number of partial webs is provided in total.

During production and subsequent further processing, the spacer strip is subjected to tension at any time along the longitudinal axis L. As a result, the spacer elements are held by means of adhesion of the partial webs of the carrier. In addition, the material of the carrier is relatively stiff, especially when manufactured from pressboard and a carrier thickness> 0.25 mm. The stiffness of the carrier causes a restoring force, since the carrier has a tendency to return to its flat original shape. The restoring force additionally causes a frictional connection, by which the spacer elements are held.

The partial webs preferably run parallel to the longitudinal axis. The subdivision of the carrier in partial webs can be done for example by means of longitudinal slots. Longitudinal slots can be produced in a simple manner.

To improve the connection between the carrier and spacer elements is provided in advantageous developments that at least one of the spacer elements on the top and / or the bottom has at least one flat groove and / or at least one shoulder for a partial web. The carrier and in particular partial webs of the carrier can be arranged in the flat groove and on the heels. In this way, it is prevented that the spacer elements slide in a direction perpendicular to the longitudinal axis L of the carrier.

In advantageous developments it is provided that the carrier has at least one of the mounting locations along the longitudinal axis L extending plug opening. A plug-in opening allows the insertion of a spacer, creating a secure connection between the carrier and spacer can be produced. In a direction perpendicular to the longitudinal axis, edge strips of the carrier, which delimit the plug-in opening, are preferably provided in addition to the plug-in opening.

In order to facilitate the mounting of the spacer elements in the plug-in opening, a spring slot adjoins the plug-in opening in the direction of the longitudinal axis, preferably at least at one end of the plug-in opening. The width of the spring slots is smaller than the width of the insertion opening. The length of the spring slot is preferably greater than / equal to the length of the plug-in opening. The total slot length SL, which designates the length of insertion opening and at least one spring slot, is preferably 2 x DL <SL <5 x DL, preferably 2 x DL <SL <3 x DL and in particular 3 x DL <SL <5 x DL. Preferably, two spring slots are provided.

At least one of the spacer elements preferably has at least one lateral guide groove running parallel to the longitudinal axis L. The edge tracks of the carrier are advantageously arranged in each case in a guide groove, whereby a positive connection is made. Preferably, a guide groove is provided on two opposite sides of the spacer element, so that the spacer element is held between the two edge webs.

In advantageous developments it is provided that the carrier has at least one of the mounting locations along the longitudinal axis L extending constriction. A constriction weakens the wearer less than through an insertion opening. At least one of the spacer elements preferably has a central, along the longitudinal axis L extending retaining groove. The carrier can be arranged with the constriction in the retaining groove, whereby a positive connection is made possible. Particularly preferably, the retaining groove of the spacer element for the carrier has a passage region with a width K1 and an end region of a width K2, wherein K2> K1. For mounting a spacer element on the carrier, the carrier can be pushed through the passage area and then reach the end region. The smaller width of the passage area prevents the carrier can fall out of the retaining groove again. Particularly preferably, the carrier has a width B4 in the region of the constriction, wherein B4> K1. Advantageously, B4> K2, so that the carrier lies under tension in the end region. In this case, the carrier is preferably deformed.

In advantageous developments, it is provided that the constriction along the longitudinal axis L has in succession an insertion region with a width B2, a retention region with a maximum width B1 and a retention region with a width B3, where B1> B2 and B1> B3. The insertion area can be inserted into a retaining groove of a spacer element. Subsequently, the spacer element along the longitudinal axis L can be moved in the direction of the holding area, wherein it first passes the retention area. Further movement along the longitudinal axis L, the spacer reaches the holding area in which it is held. The retention area prevents the spacer element from being moved back in the direction of the insertion area.

Advantageously, the width of the retention area increases continuously along the longitudinal axis L, starting from the insertion area in the direction of the holding area. As a result, the carrier in the retention area is automatically deformed when moving a spacer element from the insertion area into the retaining area, whereby the path for pushing for the spacer element is automatically released. If the spacer has arrived in the holding area, a return in the opposite direction is prevented by the retention area. Preferably, B1> K2. Thereby, the spacer is held in the holding area and a movement in the direction of the insertion is prevented. More preferably, K2> B2. This allows a simple, resistance-free insertion of the carrier in the retaining groove. More preferably, K2> B3. As a result, the holding region of the carrier can lie in the holding groove without deformation. The length of the holding region, measured in the direction of the longitudinal axis L, preferably corresponds to the spacer element length DL. Likewise, the length of the insertion region preferably corresponds to the spacer element length DL.

Advantageously, the constriction has a spring opening extending along the longitudinal axis L. The spring opening preferably extends along the holding and retaining regions. At at least one longitudinal end, the spring opening may have an additional spring slot. The spring opening allows easier deformation of the carrier perpendicular to the longitudinal axis. In this way, the assembly of the spacer elements on the carrier is facilitated.

In advantageous developments, it is provided that the support has a width TB and the spacer elements have a width DB, where TB ± 5% = DB ± 5%, in particular TB = DB. In this way, the spacer strip is given a uniform width, whereby the processing and assembly is simplified.

Advantageously, the spacer elements are all identical. As a result, the spacers can be produced more cheaply.

The transformer winding according to the invention has at least one core and arranged around a core axis K of the core conductor windings, wherein between two radially adjacent arranged conductor windings, a spacer strip according to the above embodiments is arranged. The transformer according to the invention comprises at least one spacer strip according to the above embodiments and / or a transformer winding according to the above statements.

The inventive method for producing a spacer strip according to the above embodiments comprises the following steps:

- Providing a band-shaped carrier with a longitudinal axis L;

- Providing multiple spacers;

- Arranging the spacer elements at mounting locations of the carrier and along the longitudinal axis L spaced from each other, wherein the spacer elements are non-positively and / or positively connected to the carrier.

The method according to the invention provides a spacer strip in which the spacer elements are non-positively and / or positively connected to the carrier. In this way, a cohesive connection of spacers and support can be avoided. This reduces the risk of partial discharges in a transformer in which the spacer strips produced in this way are used.

The method according to the invention can have one or more of the assembly steps described above with respect to the spacer strip. The carrier and / or the spacer elements may be formed in the method according to the invention according to one or more of the advantageous developments described above.

The invention will be illustrated and explained by way of example with reference to FIGS. It shows:

FIG. 1 a shows a transformer in a schematic representation; Figure 1 b is the section AA of Figure 1 a;

Figure 2a shows a transformer winding in a side view;

FIG. 2b shows the transformer winding of FIG. 2a in a plan view;

FIG. 2c shows the transformer winding of FIG. 2b in section A-A;

3a shows a first embodiment of a spacer strip in a side view;

Figure 3b shows the embodiment of Figure 3a in a plan view;

FIG. 3c shows the embodiment of FIG. 3a in section B-B;

FIG. 3d shows the embodiment of FIG. 3a in a bottom view;

Figure 3e is an enlarged view of the detail C of the embodiment of

FIG. 3a;

FIG. 3f shows a single spacer element of the embodiment of FIG. 3a in a perspective view;

Figure 4a shows a second embodiment of a spacer strip in a side view;

FIG. 4b shows the embodiment of FIG. 4a in a plan view; FIG. 4c shows the embodiment of FIG. 4a in section BB; FIG. 4d shows the embodiment of FIG. 4a in a bottom view;

FIG. 4e shows the embodiment of FIG. 4a in a front view;

FIG. 4f shows a single spacer element of the embodiment of FIG. 4a in a perspective view;

Figure 5a shows a third embodiment of a spacer strip in a side view;

FIG. 5b shows the embodiment of FIG. 5a in a plan view;

FIG. 5c shows the embodiment of FIG. 5a in section B-B;

FIG. 5d shows the embodiment of FIG. 5a in a bottom view;

5e the section D-D through the embodiment shown in Figure 5b in an enlarged view;

FIG. 5f shows a single spacer element for the embodiment of FIG. 5a in a perspective view;

FIG. 5g shows a modified third embodiment of a spacer strip in a side view;

FIG. 5h shows the embodiment of FIG. 5g in a plan view;

FIG. 5i shows the spacer strip according to FIGS. 5g and 5h in perspective

Presentation, FIG. 6a shows a fourth embodiment of a spacer strip in a side view;

FIG. 6b shows the embodiment of FIG. 6a in a plan view;

FIG. 6c shows the embodiment of FIG. 6a in section B-B;

FIG. 6d shows the embodiment of FIG. 6a in a bottom view;

FIG. 6e shows the embodiment of FIG. 6a in a front view;

FIG. 6f shows a single spacer element of the embodiment of FIG. 6a in a perspective view;

Figure 7a shows a fifth embodiment of a spacer strip in a side view;

FIG. 7b shows the embodiment of FIG. 7a in a plan view;

FIG. 7c shows the embodiment of FIG. 7a in section B-B;

Figure 7d shows the embodiment of Figure 7a in a bottom view;

FIG. 7e shows the embodiment of FIG. 7a in a front view; and

FIG. 7f shows a single spacer element for the embodiment of FIG. 7a in a perspective view. FIGS. 1 a and 1 b show a transformer 200 with a core 201. The core 201 consists of a U-shaped part 202 and a magnetic circuit closing yoke 203. On the core 201, two transformer windings 100 are arranged, each having a plurality of conductor windings 102. For purposes of illustration, the transformer windings 100 are identical; in practice, the input and output transformer windings of a transformer are typically different, particularly in terms of their turns, to allow transformation of an input voltage into an output voltage. The structure of the transformer winding 100 will be explained in more detail with reference to Figures 2a to 2c.

Figures 2a to 2c show a transformer winding 100 in a simplified representation with multiple conductor windings 102. The transformer winding 100 has a winding axis W. The conductor windings 102 are each arranged spirally around the winding axis W. The conductor windings 102 are wound in a disc winding manner. Each conductor winding 102 is spirally arranged in a plane perpendicular to the winding axis W. Each conductor winding 102 except the top and bottom is connected to the overlying and the underlying conductor winding 102 by connecting elements 103 such that a continuous conductor is formed between a first winding end 107 and a second winding end 108.

In the radial direction, that is to say perpendicular to the winding axis W, the conductor windings 102 are separated from one another by spacer strips 1. In other embodiments, the conductor windings 102 can be separated from one another in the vertical direction by separating elements. The conductor windings 102 have a conductor core and a sheath. The sheath is preferably made of paper.

The spacer bands 1 have a band-shaped carrier 10 and spacer elements 20. Between the conductor windings 102 and limited by the spacer elements 20 channels 104 are formed. The channels 104 are flowed through by a cooling medium, in particular oil. During operation, the cooling medium flows through the channels 104 and in this way dissipates heat from the transformer 100.

FIGS. 3 a to 3 e show a first embodiment of a spacer strip 1 according to the invention. The spacer strip 1 has a band-shaped carrier 10 with a longitudinal axis L and three spaced apart along the longitudinal axis L at mounting locations 2 spaced elements 30. In the lowest mounting location 2, the spacer element 30 is not shown. In Figure 3f, a single spacer element 30 is shown. The longitudinal axis L of the carrier 10 is also the longitudinal axis L of the spacer strip 1.

The carrier 10 has a width TB perpendicular to the longitudinal axis L. The spacer elements 30 likewise have a width DB perpendicular to the longitudinal axis L, where TB = DB. The carrier 10 has a carrier length TL along the longitudinal axis L and a carrier thickness TD perpendicular to the longitudinal axis L and perpendicular to the width TB. The carrier width TB is substantially greater than the carrier thickness TD, preferably at least 5x. The carrier length TL is substantially greater than the carrier width TB, preferably at least 10x. As a result, the carrier 10 has a band-shaped basic shape.

The spacer elements 30 (FIG. 3f) are parallelepiped-shaped and each have an upper side 21 and an underside 22 opposite the upper side 21, two opposing side surfaces 23, 24 and two mutually opposite side surfaces 23, 24. overlying end faces 25, 26. The carrier 10 and the spacer elements 30 are made of pressboard. The spacers 30 are all identical. The spacer elements 30 are each arranged at a distance A (Figure 3b) to each other.

Each spacer element 30 has a clamping groove 31. The clamping groove 31 is arranged on the underside 22 and extends from the first side surface 23 to the second side surface 24. In cross section, the clamping groove 31 is pentagonal. The spacer elements 30 are arranged on the carrier 10 such that the clamping groove 31 runs perpendicular to the longitudinal axis L of the carrier 10. At each mounting location 2, the carrier 10 is combined to form a bead 32. Each bead 32 is arranged in a clamping groove 31 and clamped there (Figure 3e). In this way, spacer elements 30 and carrier 10 are positively and non-positively connected.

The production of the spacer strip 1 can, for example, be such that initially a carrier 10 is provided and a bead 32 is formed at each mounting location 2. Subsequently, spacer elements 30 are pushed perpendicular to the longitudinal axis L on the beads 32, wherein the beads 32 are inserted into the clamping grooves 31.

The spacer strip 1 produced in this way can then be used in a transformer 100 (FIG. 2a).

FIGS. 4a to 4e show a second embodiment of a spacer strip 1. The spacer strip 1 also has a band-shaped carrier 10 with a longitudinal axis L and along the longitudinal axis L spaced from each other at mounting locations 2 arranged spacer elements 40. Again, the carrier width TB of the spacer element width DB corresponds. The spacer element 40 shown in FIGS. 4e and 4f has a parallelepiped shape and has an upper side 21 and an underside 22 opposite the upper side 21, two opposite side surfaces 23, 24 and two mutually opposite end faces 25, 26. On the upper side 21, the spacer element 40 has a flat groove 42. The flat groove 42 has a rectangular cross-section and extends from the first end face 25 to the second end face 26. The bottom 22 of the spacer element 40 is flat.

At each mounting location 2 of the carrier 10, a spacer element 40 is arranged (Figure 4b), wherein the lowermost of the spacer elements 40 is not shown. At the mounting locations 2 of the carrier 10 by means of longitudinal slots 44 in three sub-webs, that is, in a middle sub-web 41 a and two lateral partial webs 41 b, divided. The three partial webs 41 a, 41 b are parallel to the longitudinal axis L. The spacer elements 40 are held by the partial webs 41 a, 41 b, the middle part of web 41 a in the flat groove 42 on the top 21 and the two lateral partial webs 41 b run on the bottom 22. In this way, the carrier 10 and the spacer elements 40 are positively connected with each other.

FIGS. 5a to 5e show a further embodiment of a spacer strip 1 according to the invention. The spacer strip 1 has a band-shaped carrier 10 with a plurality of spacer elements 50 spaced apart from each other at mounting locations 2 along the longitudinal axis L.

The spacer element 50 shown in Figure 5f is cuboid and has a top 21 and an opposite bottom 22, two opposing side surfaces 23, 24 and two opposite end faces 25, 26. In the side surfaces 23, 24, the spacer element 50 each have a guide groove 52. The guide grooves 52 each extend from the first end face 25 to the second end face 26 and each have a rectangular cross-section.

The carrier 10 has at each mounting location 2 a plug-in opening 51 (Figure 5d). The insertion openings 51 each have the shape of a slot, wherein in the end regions along the longitudinal axis L in each case a spring slot 53 is provided. The plug-in opening 51 has a straight section with the length GL (see Figure 5b), followed by short rounded sections at both ends, which merge into the spring slots 53. Each insertion opening 51 forms with its associated spring slots 53 a common opening. Laterally adjacent to the insertion openings 51, that is, in a direction transverse to the longitudinal axis L edge webs 54 of the carrier 10 are provided. The edge tracks 54 are arranged in the guide grooves 52 of the spacer elements 50, so that the carrier 10 and spacer elements 50 are positively connected with each other.

Preferably, DL <GL, in particular DL = GL, where DL denotes the spacer element length. The width of the spring slots 53 is smaller than the width of the insertion opening 51, so that the spacer element in the insertion opening can not slip.

By the spring slots 53, the edge webs 54 can be moved away from each other in the assembly of the spacer elements 10 perpendicular to the longitudinal axis L. Subsequently, a spacer element 50 is arranged between the edge webs 54 and the edge webs 54 are pushed into the guide grooves 52.

FIGS. 5g, h, i show a modified third embodiment of the spacer strip 1. This modified embodiment differs from the embodiment according to FIGS. 5a to 5f in that the length of the both of the insertion opening 51 adjacent spring slots 53 is significantly larger. The insertion opening 51 corresponds to the insertion opening 51 from FIGS. 5a to 5f.

The length of the common opening is referred to as the total slot length SL (see FIG. 5i) and is the sum of the lengths of the plug-in opening 51 and the spring slots 53. SL is preferably 2 × DL <SL <5 × DL, preferably 2 × DL <SL < 3 x DL and in particular 3 x DL <SL <5 x DL. The choice of the slit length SL depends preferably on the stiffness of the material of the spacer strip 1.

DB denotes the spacer element width and DH denotes the spacer element height.

The advantage of long spring slots 53 is that the spacer elements 20, 50 can be used even more easily in the insertion opening 51.

Preferred dimensions of a spacer strip 1 are summarized in the following table:

Dimensions tolerances

TD 0.2 mm to 0.3 mm; ± 10%

0.25 mm

TL Max. 1500 m ± 5 m

TB 6 - 30 mm + 0 / - 0.5 mm

DH 4 - 20 mm ± 10%

DL 5 - 25 mm ± 0.5 mm

DB 5 - 30 mm + 0 / - 0.5 mm

A 20 - 100 mm ± 3 mm

"R" radius 1 - 2 mm ± 0.5 mm "R2" radius 0.5 mm ± 0.3 mm

The spacer strip 1 consists only of the carrier 10 and the spacer elements 20, which are preferably smooth on all sides and have rounded edges with the radii R and R2.

The carrier 10 preferably consists of PSP 3055 (standard IEC 60641 -3-2) and the spacer elements 20, 50 of PSP 3052 (standard IEC 60641 -3-1).

Each of these materials is a transformer presspan.

FIGS. 6a to 6e show a further embodiment of a spacer strip 1 according to the invention. FIG. 6f shows a single spacer element 60 for this embodiment.

The spacer strip 1 is also band-shaped and has a plurality of mounting locations 2, on which spacer elements 60 are arranged (Figure 6b). The lowest spacer element 60 is not shown. The carrier 10 has a carrier width TB, which corresponds to the width DB of the spacer elements 60.

At each mounting location 2, the carrier 10 has a constriction 61. In the area of the constriction, the width of the carrier 10 is less than the carrier width TB. The carrier thickness TD is unchanged. At the narrowest point, the constriction 61 has a width B4. The width B4 is measured perpendicular to the longitudinal axis L. To avoid tearing, the constriction 61 has no corner along its contour (Figure 6d).

The spacer element 60 is parallelepiped-shaped and has an upper side 21 and an opposite lower side 22, two mutually opposite side surfaces 23, 24 and two mutually opposite end faces 25, 26 (FIGS. 6e, 6f). On the underside 22, the spacer element 60 has a retaining groove 62. The retaining groove 62 extends from the first end face 25 to the second end face 26. In cross section, the retaining groove 62 is pentagonal.

The retaining groove 62 has a passage portion 63 having a width K1 and an end portion 64 having a width K2. The widths K1, K2 are each measured along a vertical connecting line between the side surfaces 23, 24. The width K2 is greater than the width K1.

During assembly of the spacer elements 60 on the carrier 10, the carrier 10 is pressed in the region of the constriction 61 through the passage region 63 until the carrier 10 reaches the end region 64. The carrier 10 is deformed in the region of the constriction 61 in the insertion into the retaining groove 62, since the width B4 of the constriction 61 is greater than the width K1. The width B4 is larger than K2, so that a small bias is generated and the carrier 10 is prevented from slipping out of the holding groove 62 due to the narrower passage portion 63. The deformation of the carrier 10 forms a bead 65.

FIGS. 7a to 7e show a further embodiment of a spacer strip 1 according to the invention. The spacer strip 1 also has a band-shaped carrier 10 with mounting locations 2. At each mounting location 2, a spacer element 70 is arranged, wherein the lowermost spacer element 70 is not shown.

The carrier 10 has at each mounting location 2 a constriction 71 (Figure 7d). In the region of the constriction 71, the carrier 10 has various widths, which are all smaller than the carrier width TB. The constriction 71 is subdivided along the longitudinal axis L into three regions lying directly behind one another: an insertion region 75, which enters a wedge-shaped retention region The insertion region 75 has a width B2, the wedge-shaped retention region 76 has a width B1 at its widest point, and the retention region 77 has a width B3. The widths B1, B2, B3 are each measured parallel to the carrier width TB.

In the retaining region 76 and the holding portion 77 of each constriction 71 a common spring opening 78 is arranged in each case. The spring opening 78 has the shape of a slot, wherein at one end a spring slot 79 extending into the insertion area 75 is provided. The spring opening 78, together with the spring slot 79, permits deformation of the carrier 10 in the retention area 76, whereby the width B1 of the carrier 10 in the retention area 76 can be temporarily reduced.

A spacer element 70 for this embodiment of the spacer strip 1 is shown in FIG. 7f. The spacer element 70 is cuboid and has an upper side 21 and an opposite lower side 22, two opposite side surfaces 23, 24 and two opposite end faces 25, 26.

The spacer element 70 has a retaining groove 72 on the underside 22. The retaining groove 72 is T-shaped in cross-section and has a passage region 73 and a wider end region 74 for the carrier 10. The passage region 73 has a width K1 and the end region 74 has a width K2. The retaining groove 72 extends from the first end face 25 to the second end face 26 and thus along the entire spacer element length DL.

During assembly, the insertion region 75 of the carrier 10 is deformed and pushed through the passage region 73 into the end region 74 of the spacer element 70. The width B2 of the insertion portion 75 is larger than the width K1, but smaller than the width K2, so that the carrier 10 is prevented from leaving the end portion 74.

Subsequently, the spacer element 70 is moved along the longitudinal axis L in the direction of the holding portion 77. As a result, it first passes into the wedge-shaped retention area 76. Since the width B1 of the retention area 76 is greater than the width K2, the support 10 is deformed, which is possible through the spring opening 78 with the spring slot 79.

By further displacement along the longitudinal axis L, the spacer element 70 passes into the holding region 77, as a result of which the retention region 76 can again assume its original shape. The width B3 of the holding portion 77 is smaller than the width K2 of the end portion 74 but larger than the width K1 of the passage portion 73 of the retaining groove 72 of the spacer member 70. In this way, the spacer member 70 is positively connected to the carrier 10. The retention area 76 prevents the spacer element 70 from moving in the direction of the insertion area 75.

The carrier 10 and the spacer elements 20, 30, 40, 50, 60, 70 of the embodiments shown are made of pressboard.

The spacer strips 1 according to the invention can in principle also have more than three mounting locations 2. List of Reference Distance Band

Mounting location carrier spacer element

top

bottom

first side surface

second side surface

first end face

second end face spacer

clamping groove

Bead spacer element

a middle partial web

b lateral partial path

flat groove

Longitudinal slot spacer element

plug-in opening

guide

spring slot Edge track spacer element

constriction

retaining groove

Passage area end area

Bead spacer element

constriction

retaining groove

Passage area end area

insertion

Retention area

holding area

spring opening

Spring slot transformer winding conductor winding

Connecting element channel first winding end second winding end transformer

core 202 U-shaped part

203 yoke

A distance

B1 width of the retention area 76

B2 Width of the insertion area 75

B3 width of the holding area 77

B4 Width of the constriction 61

DB spacer element width

DH spacer element height

DL spacer length

K1 width of the passage area 63, 73

K2 width of the end region 64, 74

L longitudinal axis

TB carrier width

TD carrier thickness

TL carrier length

W winding axis

SL slot length

GL length of the straight portion of the insertion opening 51

Claims

claims

1 . Spacer strip (1) for a transformer having a band-shaped carrier (10) extending along a longitudinal axis (L) and a plurality of spacer elements (20, 30, 40, 50, 60) arranged at mounting locations (2) spaced apart along the longitudinal axis (L) , 70), characterized in that the spacer elements (20, 30, 40, 50, 60, 70) are non-positively and / or positively secured to the carrier (10).

Second spacer strip (1) according to claim 1, characterized in that between the carrier (10) and the spacer elements (20, 30, 40, 50, 60, 70) is no material connection.

3. spacer strip (1) according to claim 1 or 2, characterized in that the carrier (10) and / or the spacer elements (20, 30, 40, 50, 60, 70) made of pulp and / or wood pulp, in particular from pressboard, consist.

4. spacer strip (1) according to one of the preceding claims, characterized in that at least one of the spacer elements (20, 30, 40, 50, 60, 70) at least one groove (31, 42, 52, 62, 72), in which of the carrier (10) is arranged.

5. Distance tape (1) according to one of the preceding claims, characterized in that at least one of the spacer elements (30) has a perpendicular to the longitudinal axis (L) extending clamping groove (31) in which a bead (32) of the carrier (10) is arranged.

6. spacer strip (1) according to one of the preceding claims, characterized in that the carrier (10) on at least one of the assembly (2) is divided into at least three partial webs (41 a, 41 b), wherein at least one partial web (41 a) on an upper side (21) of the spacer element (40) and at least two partial webs (41 b) on one of the upper side ( 21) opposite underside (22) of the spacer element (40) extend.

7. spacer strip (1) according to claim 6, characterized in that the partial webs (41 a, 41 b) parallel to the longitudinal axis (L).

8. spacer strip (1) according to claim 6 or 7, characterized in that at least one of the spacer elements (40) on the upper side (21) and / or the underside (22) at least one flat groove (42) and / or at least one shoulder for a partial path (41 a, 41 b).

9. spacer strip (1) according to one of the preceding claims, characterized in that the carrier (10) at at least one of the mounting locations (2) along the longitudinal axis (L) extending plug opening (51).

10. spacer strip (1) according to claim 9, characterized in that the insertion opening (51) in the direction of the longitudinal axis (L) at least at one end of the insertion opening (51) is followed by a spring slot (53).

1 1. Distance band (1) according to claim 9 or 10, characterized in that at least one of the spacer elements (50) has at least one lateral, parallel to the longitudinal axis (L) extending guide groove (52).

12. Distance strip (1) according to one of the preceding claims, characterized in that the carrier (10) at at least one of the mounting locations (2) extending along the longitudinal axis (L) Einschnü- tion (61, 71).

13. Distance tape (1) according to claim 12, characterized in that at least one of the spacer elements (60, 70) has a central, along the longitudinal axis (L) extending retaining groove (62, 72).

14. spacer strip (1) according to claim 13, characterized in that the retaining groove (62, 72) has a passage region (63, 73) for the carrier

(10) having a width K1 and an end region (64, 74) for the carrier (10) having a width K2, where K2> K1.

15. Distance tape (1) according to claim 14, characterized in that the carrier (10) in the region of the constriction (61) has a width B4, wherein B4> K1.

16, spacer strip (1) according to one of claims 12 to 15, characterized in that the constriction (71) along the longitudinal axis (L) in succession an insertion region (75) with a width B2, a retention area (76) with a maximum width B1 and a holding region (77) having a width B3, where B1> B2 and B1> B3.

17. Distance tape (1) according to claim 16, characterized in that B1> K2 and K2> B2 and K2> B3.

18. Distance tape (1) according to one of claims 12 to 17, characterized in that the constriction (61, 71) has a along the longitudinal axis (L) extending spring opening (78).

19. Distance strip (1) according to one of the preceding claims, characterized in that the carrier (10) has a width TB and the distance elements (20, 30, 40, 50, 60, 70) have a width DB, where TB = DB.

20. Distance tape (1) according to one of the preceding claims, characterized in that the spacer elements (20, 30, 40, 50, 60, 70) are all formed identically.

21. Transformer winding (100) having at least one core (101) and arranged around a core axis (K) of the core (101) conductor windings (102), wherein between two radially adjacent arranged conductor windings (102) a spacer strip (1) arranged according to one of the preceding claims is.

22. Transformer (200) with at least one spacer strip (1) according to one of claims 1 to 20 and / or with a transformer winding (100) according to claim 21.

23. A method for producing a spacer strip (1) according to one of claims 1 to 20, comprising the following steps:

- Providing a band-shaped carrier (10) having a longitudinal axis (L);

- Providing a plurality of spacer elements (20, 30, 40, 50, 60, 70);

- Arranging the spacer elements (20, 30, 40, 50, 60, 70) at mounting locations (2) of the carrier (10) and along the longitudinal axis (L) spaced from each other, wherein the spacer elements (20, 30, 40, 50, 60 , 70) are positively and / or positively connected to the carrier (10).