SU1243056A1 - Brush-commutator unit of electric machine - Google Patents

Abstract

The brush-collector unit is intended for use in electric machines operating at a high current density in a sliding contact, under the conditions of difficult commutation, and significant vibration and shock loads, for example, in traction electric machines. The aim of the invention is to increase the wear resistance of the brushes and the collector, reducing the rate of winding: nodding the inter-lamination gaps of the collector with copper by maintaining the working area of the contact area under conditions of frequent reversing of the electric machine. The brush-collector unit contains split elementary brushes (ES) 1 located in the holder 2 of the brush holder and collector 3 of the electric machine. According to the plane of symmetry of the holder 2, which coincides with the plane of cutting the brushes, on the lateral internal surfaces of the holder 2 in a tangential direction (O (L FIG. 1)

Description

The projections are made along the entire height of the cage, having a cross-section, perpendicular to the height of the cage, the shape of a rectangular triangular triangle, the apex of the right angle of which is in the plane of symmetry of the cage,

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The invention relates to electrical engineering and relates to brush-collector assemblies of electric machines operating at a high current density in a sliding contact, in the conditions of difficult switching, significant vibration and shock loads, for example, traction electric machines.

The aim of the invention is to increase the wear resistance of the brushes and the collector, reducing the speed of covering the interlaminate gaps of the collector with copper by maintaining the working area of the contact area under the conditions of frequency reversal of the electric machine.

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FIG. 1 shows schematically a brush-collector unit of an electric machine, general view; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. .

The proposed brush-collector assembly includes split elements. mental brushes 1, placed in the holder 2 brush holders, and the collector; 3 electric machines. Along the plane 4 of the symmetry of the holder 2 of the brush holder, which coincides with the plane of cutting the brushes, on the lateral internal surfaces of the holder) protrusions 5 are arranged in a tangential direction along the entire height of the holder, having a cross section, perpendicular to the height of the holder, the shape of an equilateral circumferential triangle, the height is equal to the angle of which is in the plane of the metric of the holder, the ratio of the size of the leg (k) of the rectangular triangle to the tangential size of the elementary brush (t) is in the range of 0.08-0.33, and in the place of cutting the element Tarn brush 1 formally coincides with the geometrical dimensions of the projections 5,

The ratio of the size of the leg of the rectangular triangle to the tangential size of ESh 1 is in the range of 0.08-0.33, and at the place of cutting ESh 1 in shape coincides with the geometric dimensions of the projections. 3 il.

five

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five

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When the ratio of the size of the leg of the triangle to the tangential size of the elementary brush extends beyond the specified limits, the operation of the brush-collector unit is impaired. At lower ratios due to friction and vibration loads when reversing an electric machine, the side surfaces of the elementary brushes are mechanically destroyed at the points of contact with the surfaces of the protrusions, resulting in the tilting of the elementary brushes during reversals and an increase in the wear of the brushes. for switching overloads of the sliding contact due to the formation of a double mirror and a significant decrease in the actual contact area.

At large ratios, the cross-sectional area of the brushes significantly decreases, as a result of which the actual current density in the contact increases, which leads to deterioration of the switching properties of the current collection unit, accompanied by increased brush wear and electrical breakdown of the electric machine.

During the long-term operation of the electric machine, the burnings of the brushes and the collector are observed, which are associated with the presence of overheating of the contact, which can lead to the dissolution of the collector. At the same time, the wear of the elements of the brush-collector unit increases. When the ratio of the size of the leg of the triangle; to the tangential size of the elementary brush, which differs from the indicated limits, the difficulty of manufacturing the elementary brushes and the brush holder holders increases, the operation of assembling the brushes is complicated.

Ngshichie protrusions located in the tangential direction on the boom surfaces of the brush holder clips, allows you to neutralize the effect of friction forces tilting brushes when reversing the electric machine. Therefore, the tilting of the elementary brushes does not occur and the working contact surface does not undergo major changes.

Improving the stability of the working area of the contact ensures uniform current flow during the reverse. In this case, there are breakdowns in the commutation and disruption of the political formation, overheating of the contact surface of the collector, the coefficient of friction, wear rates of the brushes AND the collector remain stable, and no conditions are created for the occurrence of covering the collector.

The use of the proposed brush-collector assembly allows the following advantages to be realized: there is no breakdown of the electrical machine switching at the moment of its reversal; the wear resistance of brushes increases under the conditions of frequent reversals of the electric machine (1.3-1.6 times at the stand, by 14-26% in operation); the speed of occurrence of covering of collectors during runs is reduced

2430564

56-63 thousand km, covering the collectors was not detected.

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The formula of the invention The brush-collector assembly of an electric machine, containing a brush holder, in the cage of which are placed split elementary brushes and a collector, characterized in the contact area under conditions of frequent reversing of the electric machine, on the side surfaces of the holder in the tangential direction along the plane of symmetry of the holder coinciding with the brush cutting plane, protrusions along the entire height of the holder, having a cross-section, perpendicular height of the holder, an isosceles right rectangular triangle, the top angle of which is in the plane of symmetry of the holder, the ratio of the size of the leg of the right angle selected in the range of 0.08-0.33, and in the place of cutting the elementary brush repeats the shape of the protrusion on the holder.

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Compiled by V. Chernov Editor A. Vorovich Tekhred L. Oleinik Proofreader A. Zimokosov

Order 3713/53 Circulation 597 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, .Raushsk nab., d.-4/5

Production and printing company, Uzhgorod, st. Project, 4

Claims (1)

Claim Brush-collector assembly of an electric machine, containing a brush holder, in the holder of which split elementary brushes and a collector are located, characterized in that, in order to increase the wear resistance of the brushes and the collector, reduce the speed of copper covering the interlamellar * * · collector gaps, maintain a constant contact area under conditions of frequent reversal of the electric machine, on the lateral surfaces of the cage in the tangential direction along the plane of symmetry of the cage, which coincides with the plane of cutting u Therefore, protrusions are made along the entire height of the holder, having a cross section perpendicular to the height of the holder, the shape of an isosceles right triangle whose vertex of the right angle is in the plane of symmetry of the holder, and the ratio of the size of the leg of the right triangle to the tangential size of the elementary brush is selected within 0.08 –0.33, and at the place of cutting, the elementary brush repeats the shape of the protrusion on the clip. Aa Fig.Z