Alstom Technology Limited

Abb Research Ltd.

Johann Christoph Nienburg

Thomas Baumann

Josef Wittmann

Gunter Borner

J&ouml;rg Sopka

Jörg Sopka

Gunter B&ouml;rner

Jorg Sopka

Jörg Oesterheld

Lars-Erik Johansson

Enar Ahlbert

Anton Puhane

The present invention discloses a process for producing a high-quality insulation for conductors or conductor bundles of electrical machines by means of spray-sintering. Unlike in the prior art, it is possible to apply internal corona-discharge protection, insulation and external corona-discharge protection to conductors or conductor bundles in which, on account of a very low level of defects in the insulation and its inherent resistance to partial discharges, it is possible to dispense with the use of winding processes using glass/mica tapes. This eliminates the need to use complex special equipment and allows the throughput times to be shortened considerably.

Method for producing a high-quality insulation of electric conductors or conductor bundles of rotating electrical machines by means of spray sintering

A process for producing insulations for electrical conductors by powder coating, which results in aging which is improved compared to glass-mica or casting-resin insulation, and a powder which is suitable for such a process. The powder is applied a number of times in succession, in the form of individual layers which follow one another, until a layer thickness of &#x2266;10 mm is reached, and each of the individual layers undergoes intermediate heat curing before the next individual layer is applied. The intermediate curing of each individual layer uses a curing time which corresponds to 2-10 times the gel time of the powder used. Finally, the entire insulation undergoes final curing. The result of an electrical life test carried out on various specimens insulated with epoxy-resin powder which contains fine filler.

Process for producing insulations for electrical conductors by means of powder coating

The invention discloses a process for producing a high-quality insulation on a conductor or conductor bundle of rotating electrical machines, in which, in successive immersion passes in a fluidized-bed sintering tank, internal corona-discharge protection, insulation and external corona-discharge protection are applied, in each case with layer thicknesses of &lE;0.2 mm. The sintering and curing take place at temperatures of approx. 200&deg; C., so that it is possible to use materials which satisfy the demands which are imposed on the insulation of conductors or conductor bundles of this type for rotating electrical machines. Furthermore, the production process, in particular the layer thickness selected for the individual layers, ensures that the individual layers are free of defects, so that it is impossible for there to be any partial discharges, which would otherwise lead to damage to the insulation.

Method for producing a high-quality insulation of electrical conductors or conductor bundles of rotating electrical machines by means of fluidized-bed sintering

A powder-spraying apparatus having simultaneous internal and external charging, which is suitable for electrostatic powder coating. In order to achieve improved constancy of the deposition efficiency, largely independent of the distance between the powder-spraying apparatus and the work piece, it is proposed to connect both internal high-voltage electrodes and external high-voltage electrodes to a high-voltage source via high-resistance components.

Powder-spraying apparatus with internal and external charging

A process and a dispersion apparatus for shaping a powder cloud emerging from a powder spraying apparatus achieve large powder clouds and good electrostatic charging by directing control air in a tangential direction towards a powder/air stream flowing through the dispersion apparatus in an axial spraying direction. A helically accelerated movement of the powder/air stream in the direction of an outlet is achieved thereby.

Dispersion apparatus and process for producing a large cloud of an

A method and a device for controlling the outflow of fluid powder from a container can be used for controlling the expulsion of powder out of a powder-spraying apparatus for electrostatic coating. The disadvantages of a mechanical closing device are avoided by introducing closing air into an extraction pipe for extracting fluidized powder out of a container. The closing air is introduced through a pipe which opens into an orifice in the casing of the extraction pipe. The mass flow of fluidized powder can be controlled by an appropriate setting of a pressure in the extraction pipe in relation to the pressure in the fluid bed, that is to say by the introduction of closing air at an appropriate pressure.

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Heidelberg, Germany

Johann Christoph Nienburg