SU1644267A1 - Brush assembly of electric machine - Google Patents

Description

Phage.1

body 2, pressure 3 and additional 4 springs, a thrust plate 5 and a movable locking system are inserted, which consists of two leaf springs 6 with upper 7 and lower 8 protrusions at the ends and two support plates 9. With partial wear of the brush, the movable locking system works, the support plate 5 moves downwards under the action of an additional spring 4 and ensures the initial calculated pressure of the pressure spring 3 on the brush 1. 4 sludge.

FIELD OF THE INVENTION The invention relates to electrical engineering and relates to the design of the brush holders of electrical machines, providing continuous current collection from rotating parts, for example a collector or contact rings.

The purpose of the invention is to provide a constant amount of pressure on the brush as it wears.

FIG. 1 shows the brush assembly in its original position, longitudinal section; in fig. 2 - the same, at the moment the locking system operates, a longitudinal section; in fig. 3 - support plate; in fig. 4 - brush holder.

The brush unit of an electric machine consists of a brush 1 placed in the brush holder 2, above which a pressure spring 3 and an additional spring 4 are placed, and a stop plate 5 is placed between them. The latter is installed in certain positions with the help of a movable system of clamps, which consists of two plate-shaped springs 6 with top 7 and bottom 8 protrusions at the ends and two support plates 9. Support plates 9 are fixed on the outside of the brush holder 2 with a L-shaped protrusion 10 and stops 11. In that part of the support plate 9, which is outside the brush holder 2, a slot 12. is made. A slot spring 6 is inserted in the slot 12, the protrusions 7 and 8 of which are installed in the longitudinal grooves 13 in the brush holder 2. In addition to the four longitudinal grooves 13, two L-shaped slots 14 in which the support plates 9 are inserted into the L-shaped protrusions 10. Such design of the brush holder provides ease of assembly and sufficient mechanical strength when assembled. When a new brush is installed in the brush holder 2, the brush 1 is not yet activated, the lower lugs 8 of the leaf springs 6 abut against the side surface of the brush 1, and the upper lugs 7 are inserted into the groove 13 so that a part of them protrudes inside the brush holder 2 and holds the stop plate 5 in the upper the position in which the pressure spring 3 provides the initial design force for pressing the brush 1 (FIG. 1). As it operates, the brush 1 moves

way down. At the same time, the pressure spring 3 is slightly unclenched and, consequently, the pressure on the brush decreases, but at the same time the lower projections 8 of the leaf springs 6 approach the edge of the brush 1. With the further operation of the brush 1, the lower projections 8 of the leaf springs 6 come off the brush 1, the springs operate 6, the upper protrusions 7 of the leaf springs 6 partially exit from the brush holder 2 and release the support plate 5, which moves downward under the action of the additional spring 4, the stiffness of which is more than the stiffness of the pressure spring 3. Moving the support plate 5 is limited by the internal protrusions of the support plates 9, which are placed on the brush holder 2, so as to ensure the initial calculated pressure of the pressure spring

0 per brush 1. If necessary, in the proposed brush assembly one can perform several steps of adjustment.

Making the supporting plates 9 with the G-shaped lower protrusion 10 and the upper lugs 11 (FIG. 3) allows the support plate 5 to be secured 5 from vertical movements. The mounting plate 9 on the brush holder 2 is installed by simply inserting the L-shaped protrusion 10 of the base plate 9 into the L-shaped slot 14 made in the brush holder 2. The selection of the shape of the protrusion 10 on the base plate 9 and the corresponding slot 14 in the brush holder 2 is caused by the desire to ensure simplicity construction and reliability of fastening of all structural elements.

5 The application of the proposed brush assembly makes it possible to ensure an almost uniform pressing of the brush over the entire service life at which optimum conditions for the operation of the brush-collector contact are achieved. AT

50 of the proposed brush assembly, the initial pressing of the brush is lower, and pressing with the full permissible actuation of the brush is higher than the known, which allows reducing mechanical friction losses of the brush against the collector with a new brush and ensuring reliability of the brush-collector contact with extreme wear of the brush, as a result, the service life of the collector electric machine is increased.

Studies of the brush unit of the DK 58-60-20 electric motor, taken as a base, showed that when using a pressure spring that ensures stable operation of the brush-collector contact with the maximum wear of the brush, the magnitude of the mechanical losses when the brush is not worked out is twice as high recommended value. The use of a weaker pressure spring leads to an unacceptable spark on the collector with the maximum wear of the brush.

Claims (1)

Invention Formula The brush unit of an electric machine containing a brush holder, in which a brush, a pressure and an additional spring are installed, between which a stop plate is installed, characterized in that, in order to ensure a constant amount of pressure on the brush as it wears, it is equipped with two plate springs with protrusions at the ends and located on the outer sides of the brush holder and two support plates, by means of which the leaf springs are fixed on the brush holder, the protrusions of the leaf springs and the support plates are installed in the longitudinal lengths additionally made in the brush holder troughs and l-shaped slits. 72 Fig.z FIG. four 73