DE8319428U1 - Anisotropic, one-piece pressed carbon brush for electrical machines - Google Patents

Description

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The invention relates to an anisotropic, one-piece pressed carbon brush for electrical machines, consisting from a carbon brush body in a multilayer structure, the layers of which are essentially perpendicular to the direction of movement one of the carbon brush associated collector runs, with at least two of the separated Layers of carbon brush material of conventional quality consist.

Such a carbon brush is described in the German utility model 79 17 605 of the applicant. To achieve a particularly quiet run when in use of this known carbon brush there is the separating layer located between the layers in conventional quality from a molding material with a film-forming additive. When running one equipped with these carbon brushes electric machine, the film-forming additive causes a noticeable noise reduction.

The invention is based on the object, while maintaining the described principle of a multilayer Structure of an anisotropic and one-piece pressed carbon brush to design this so that in particular the Sparking is reduced in a controlled manner.

To solve this problem, the invention is characterized in that that the separating layer between these two layers of conventional quality has an ohmic resistance which is greater than that of the two layers adjoining it.

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The separating layer or the middle layer is thus given by adding the carbon brush powder accordingly an ohmic resistance precisely matched to the respective conditions, which causes sparks to form when running electrical machines equipped with such carbon brushes are noticeably reduced and adapted * The den Admixtures of the separating layer influencing ohmic resistance are selected according to the respective conditions * you consists preferably of natural graphite with additional binders in a suitable, respectively coordinated proportion that defines the Ohmic resistance of the separating layer.

The invention is explained in more detail below in an exemplary embodiment from which further important ones emerge Features result in * It shows:

Fig. 1 - a perspective partially sectioned first embodiment of a novel Carbon brush on a collector;

FIG. 2 is a perspective view corresponding to FIG. 1 in a second embodiment; FIG.

Fig. 3 - a perspective view accordingly

1 and 2 in a third embodiment.

The carbon brush shown in Fig. 1 consists of two brush parts 1 and 2, which are integral with a known Tool are pressed. The direction of pressing is indicated in FIG. 1 by the arrow 3. The brush part 1 consists of conventional quality, which is adapted to the respective mechanical and electrical requirements. That-

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The same applies to another brush part 2.

The two brush parts 1, 2 are separated from one another and of course also connected to one another by a separating layer which, according to the invention, consists of graphite powder to which a suitable binding agent is mixed in a predetermined percentage. The separating layer 4 is relatively thin, for example approximately 1 mm thick * _f The figure also shows that the two layers 1 can have 2 different starch /. A connecting conductor cable 6 is connected to the thicker layer 1 * Pos. 7 indicates a collector. The carbon brush usually forms a small angle 8 with the lamellae of the collector, which is for example 4 °.

The structure of the carbon brush according to FIG. 2 is basically similar to that according to FIG. 1, but with the two layers 1, 2 in the embodiment of FIG. 2 are approximately the same thickness.

Fig. 3 shows a multilayer structure with a total of three layers 1, 2 of conventional quality, each are connected to one another via a separating layer 4 of the composition described.

The connecting conductor cable 6 preferably protrudes, contrary to the drawing, from the upper end of a layers 1, 2 out.

Claims (1)

claim Anisotropic, one-piece pressed carbon brush for electrical machines, consisting of a carbon brush body in multilayer construction, the layers of which are essentially perpendicular to the direction of movement of one of the Carbon brush associated collector runs ^ with at least two of the separated layers from Carbon brush material of conventional quality, as characterized by that the separating layer (4) between these two layers (1, 2) has an ohmic resistance which is greater than that of the two adjoining layers (1, 2). The patent attorney: Dr. D / Gudel