SU9192A1 - Brush for electric collector machines - Google Patents

Description

In electric collector machines, when sections pass from one winding branch to another, the current in the short-circuited brush section changes in size and in direction, t, -e. the so-called switching process is performed. Excessive current density under the incident and escaping edge of the brush, resulting in the appearance of reactive electromotive force in short-circuited turns, and in collector AC machines, in addition, transformer electromotive force that violates linear commutation is spontaneous brushes. One of the auxiliary means of the splitting of a sparkless opening by the brushes of an additional short-circuit current is the use of a special type of brushes with a large relative resistance in the transverse direction. By limiting the additional short-circuit current, these brushes have absolutely no effect on the decrease in the main current in the opening coils, and consequently, on the fraction of the current density caused by it under the sweeping edge of the brush.

The present invention relates to a brush for electric collector machines and aims to achieve sparkless switching by making a brush, the longitudinal and transverse resistance of which increases from the middle to the edges, and thus limits not only the additional, but also the main current in the short section.

In FIG. Figure 1 shows a longitudinal section of the brush, the part of which is adjacent to the collector is made of layers of conductive material, isolated from each other; FIG. 2 shows a modification of the proposed brush, in which the part adjacent to the collector is made of alternating layers of material of different conductivity.

The proposed brush consists of two parts, wherein part B, which enters the current-carrying ferrule, is made of coal, graphite or metal, so that the transverse resistance of the brush increases from the middle of the brush to its edges, and the other, adjacent to the collector part A, having the same hardness over the entire surface of contact with the collector, is made of

metal, graphite or coal X layers, materials of the same conductivity, isolated from each other. other layers of insulating mass (Fig. 1), or of alternating layers a, b of a material of different conductivity (Fig. 2). The thickness of metal, graphite or coal layers is desirable to take less than the width of the insulation between the collector plates.

When the brush runs off the collector plate, due to the large longitudinal and transverse resistance of the brush edge, the additional and main current and short-circuiting section, and thus the current density will be reduced, which is a favorable circumstance for non-sparking switching.

The subject of the patent.

1. A brush for electric collector machines, characterized in that it consists of two parts, of which part B, which is included in the current-carrying case, is made of coal, graphite or metal, so that the transverse resistance of the brush increases oi of the middle of the brush to its end, and the other, adjacent to the collector, part L. is made of metal, graphite or coal layers X of material of the same conductivity, isolated from each other by layers Y of insulating mass (Fig. 1)

2. Alteration of the brush described in paragraph 1, characterized in that the part adjacent to the collector is made of alternating layers and, b of different conductivity material (Fig. 2).

fig 2