WO1998022960A1 - Winding for electronically switched reluctance motors - Google Patents

Abstract

This winding comprises at least two reciprocally insulated, leading copper or aluminium strips (112, 113). These strips (112, 113) are being wound simultaneously on top of each other. The insulation between the leading strips (112, 113) is usually a plastic foil. The coil is rigidised by thermal or chemical bonding. The coil terminals are led out by properly folding the ends of the leading strips (112, 113).

Description

 Winding for electronically commutated reluctance motors.

The invention relates to a winding for the electromagnets of the electronically commutated reluctance motors, the so-called SR motors, a winding which is mounted on a magnetic yoke.

5 A large number of such electromagnets form the excitation part (stator) of the SR motor.

At least one side of this electromagnet is provided with a pole face, which faces a mobile part (e.g. rotor) via an air gap. It is proposed to provide a U-yoke made of stacked sheets with two band windings, one winding as

10 energy converting main winding acts and the adjacent one as a secondary winding

Recovery of the shutdown energy is used.

Disadvantage: interlocks are difficult to detect, two bandwidths are necessary, difficult tape guidance, the two windings are located over different areas

^{1 5 of} the magnetic path.

Such an electromagnet is known from the prior art of the SR motor according to the application PCT-RO 00012 (WO 96/09683), where electronic circuits suitable for operating the electric motor are also described.

- ^υ The invention has for its object an economically producible winding of the above

. To describe ax that allows maximum material utilization of the electrical and magnetic parts, which serves as part of an SR motor with an electrical circuit to recover the demagnetizing energy.

The problem is solved as shown in the main claim, the remaining claims concretizing several application examples.

The winding consists of at least two strip conductors 112 (main conductor) or 1 13 (secondary conductor), which are wound simultaneously and are galvanically insulated by two insulation layers 115, 115 ^' .

The strip conductors are preferably made of aluminum or copper or aluminum and copper (possibly as a bimetal) and can be realized as longitudinal cuts from a thin sheet.

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As a rule, the two strip conductors have the same width, but can, if it appears expedient, have different widths. The electrically relevant cross-section is preferably selected by choosing the correct tape thickness. Each of the strip conductors 112 and 113 can be designed as individual strips or as

40 layers, e.g. B. the winding 112 can be formed from two adjacent strips of 0.15 mm each (total thickness 0.3 mm), the winding 113 consisting of only one 0.15 mm strip.

In this way, depending on requirements, the stock keeping (only 0.15 mm tape) is simplified or

45 improves the flexibility of a conductor. Depending on the application (weight and conductivity requirements), you can use copper, for example

Combine aluminum bands

The insulation layers 115 preferably consist of a thin insulation film (thickness as a guideline approx. 10 to 50 μm) made of known materials such as polyester (Mylar). Polyimide. Paper, etc. As a special case, the insulation film could also consist of a lacquer layer applied to the strip conductor (s). This solution, however, can have disadvantages such as

Edge sensitivity, effort in stripping the ends, etc. have

The width of the insulation foils 115, 115 ^' in a winding according to FIG. 1 is greater than the width of the strip conductors 112 and 113. This precludes the possibility that there may be contact with deviations in the position or burrs of the strip conductors due to protruding edges (short circuit)

The edges of the insulation 115 can subsequently be thermally melted (sealed) if the material used (polyester) has thermoplastic properties

The short-circuit freedom of the winding can be easily monitored even during the winding process, see Fig. 1

A voltage (U) is applied in series with an indicator, for example a lamp, to the two strip conductors 112 113. A short circuit arises due to insulation or process errors. the circuit closes and the lamp signals the fault

This type of winding can be self-supporting, as well as on a (plastic) winding body. Depending on the ambient conditions, a winding can be soaked or glued with resin or other plastic in liquid or powder form, so that in the latter case only one

Edge hardening occurs

This impregnation can be carried out after winding with known means such as

- impregnation by eaves or under vacuum,

- External coating with powdered resin, or it can also take place during winding, as follows one or more tapes are coated beforehand or immediately on the winding machine with a post-polymerizable mass, this polymerizing should take place during the winding or post-processing, this being the case by adding a catalyst, UV rays, heat or simply by the absence of air between the turns in contact (with anaerobic adhesive)

The metallic tapes are, for example, coated beforehand with a polymerizable mass, and the insulating films are provided with a layer which reacts with the former (catalyst, activator) so that the tapes come into contact with the films during winding. Due to the winding pressure, part of the polymerizable mass is then displaced to the outside, this mass curing (polimerized) in a short time, so that after winding, the entire coil is solidified by the mutual bonding of the turns. The steps in making a winding:

5 - The beginnings of bands 1 12 and 113 are folded by 90 ° and with intermediate ones

Insulating films attached to the rectangular winding reel. If necessary, the bobbins are attached to the reel in advance. Depending on requirements, the tapes or insulating films are covered with a polymer or catalyst layer.

10 Several windings can be carried out simultaneously on the same winding reel.

- The coiler is rotated according to the number of turns to carry out the main (112) or secondary winding (1 13). The conductive tapes and the insulating foils are pre-stressed during the winding process.

1 Heat or UV rays are applied as needed to polymerize the resin layer (if present). The strips are cut and folded taking into account the end connections in order to achieve an axial outlet or are contacted or fixed in a suitable manner.

- ^υ - The winding reel may be turned one or two turns to insulate the winding from the outside.

- The insulation film is cut off and its end attached to the winding.

- The winding reel is pulled off and the winding is finished.

^{* "■} 'The winding according to Fig. 1, where two individual windings are shown the (sketched with bold dashed line) on a U-yoke should be mounted, an embodiment of the invention is preferably used.

The. Beginnings of the identical windings P and S are connected when the

30 windings - as preferred - can be connected in series.

The windings inserted on the left (L) and right (R) on the U-yoke are functionally connected to one another (112 left -112 right, 113 left -113 right). The beginnings of the windings, which are angled parallel to the legs, can still do this

33 are folded once in the direction of the central part of the yoke. (see FIG. 1) The overlapping beginnings of the strip conductors arriving from the left and right can be soldered or ultrasonically welded and thus mechanically and electrically connected to one another.

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A parallel connection of the windings is also possible, e.g. B. when it comes to using the windings of the previous series connection at a voltage twice as low

The electrical connection of the strip conductors connected in series is then made to the

45 ends of the left or right winding. The advantages of the invention are:

- A high utilization of the winding space (conductor filling factors up to over 90%). which often allows a conventional copper winding (copper filling factor max. approx. 50%) to be replaced by a lighter aluminum strip winding without electrical disadvantages

- Easy to manufacture, since the well-flexible tape replaces a thick, difficult to bend copper wire,

- The stripping of the winding ends is not necessary, since they are made from bare tape.

Claims

Claims: 1 winding for electromagnets, which form the excitation part of an electronically commutated reluctance motor, consisting of layers of metallic, band-shaped conductors and insulation layers, characterized in that this winding consists of at least two mutually insulated band conductors (112, 113), which together overlap and with one another insulated, which are simultaneously wound in the form of coiled turns. 2. Winding according to claim 1, characterized in that the conductive strips (112, 113) carry no insulation and are interposed between the insulating foils (115, 115 ') for the purpose of insulation. 3. winding, according to the preceding claims, characterized in that a conductor (112 or 113) consists of at least two identical or different metallic layers. 4. winding, according to the preceding claims, characterized in that the different tapes (112, 113) and insulating films (115) are glued to one another and / or covered with an insulating polymer. 5. winding, according to the preceding claims, characterized in that the liquid polymer and possibly a polymerizing agent are applied to the tapes (112, 113) or foils (115) which have not yet been wound, so that they subsequently polymerize through the turn contact. 6. winding, according to the preceding claims, characterized in that the polymer which sticks the turns cures by itself in the absence of air in a gap. 7. winding, according to the preceding claims, characterized in that the edges of the thermoplastic insulating films (11, 115 "), which exceed the width of the electrically conductive tapes (112, 113), are melted to seal the side flank of the winding.