JPS60200744A - Brush wear detector of rotary electric machine - Google Patents

Abstract

PURPOSE:To obtain a rotary electric machine which has high reliability by opposing the cutting surface of an optical fiber to the side opposed to a brush retainer, and detecting the wear amount of a brush by the presence or absence of a light transmission. CONSTITUTION:A brush 2 which is inserted into a brush retainer 1 is contacted with a rotary current collector 17 of a rotary electric machine and energized. Since the brush 2 is worn by the operation of the machine, the timing change of the wear amount is detected to prenotify the exchanging time of the brush 2. The brush wear detector has a plurality pair of holes 14 at the opposed sides of the retainer 1, and an optical fiber 13 inserted fixedly to be opposed to the holes 14. Thus, a light is transmitted from a light source 15 from the end of one optical fiber 13, a photodetection indicator 16 is provided at the end of the outher optical fiber 13 to detect and indicate the transmitted light. Thus, the source 15 can be mounted separately from the retainer 1 which is frequently vibrated to extend the life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention-1 relates to a brush wear detection device for detecting wear of brushes of a rotary chamber machine.

[Technical background of the invention and its problems]

BACKGROUND OF THE INVENTION Generally, in rotating electric machines, brushes are used to supply power to a rotating body or to collect power. As this brush, carbon brushes or metal graphite brushes are used in very ordinary rotating electric machines, and brushes wear out due to sliding with rotating current collectors such as commutators and current collecting rings.
When the brush wears down to a certain predetermined amount, it must be replaced with a new brush. Normally, brushes are replaced as necessary by regularly or occasionally checking the state of wear of the brushes, but depending on the model, the wear and tear of the brushes may not be constant. For example, brushes differ depending on their sliding speed, ambient temperature and humidity, current density, etc. Therefore, in models where the sliding speed, current flow, etc. change drastically, the wear rate is not constant, and inspection cannot be carried out at an appropriate time. Therefore, such models must be constantly inspected. or,
Furthermore, even if it is necessary to inspect the wear condition of the brush, the brush holder, its supporting iron, lead wires, etc. are arranged in a complicated manner in a small space around the brush, making it extremely troublesome to inspect the brush itself. .

For this reason, in the past, methods have been devised that do not require directly approaching the rotating electric machine to inspect the brushes themselves, and some have been implemented in some cases. One of them is the brush holder (1) as shown in Figures 1-3.
A light source (5) and a light receiving part such as a phototransistor (
6) is provided in close proximity to the brush (2), and this light source (5)
Apply current from the power supply αω to turn on the brush (
2) is worn out and the light beam reaches the light receiving part (6), it is detected by the display lamp, but in this method, if there are many brushes, the light source is not applied to each brush. In addition, the number of detection devices (12) for detecting the normality of the light source circuits is also required as many as the number of light sources, making the circuit complex.

Furthermore, since the light source is directly attached to the brush holder, which is subject to a lot of vibration, there is a drawback that the light source is cut off due to vibration during operation, which hinders stable detection over a long period of time.

[Purpose of the invention]

The object of the present invention was made in view of these drawbacks, and is to provide a highly reliable brush wear detection device that can detect the amount of wear on a brush even when the brush is far away and cannot be seen, and that uses a small number of light sources. There is a particular thing.

[Summary of the invention]

That is, in the present invention, the cut surfaces of the optical fibers are faced to opposite sides of the brush holder, one optical fiber is connected to a light source, the other optical fiber is connected to a light detection sensor,
The amount of wear on the brush is detected based on the presence or absence of light transmission between the light source and the light detection sensor.

[Embodiments of the invention]

A practical example of the present invention will be explained below with reference to FIGS. 4 to 6. In FIG. 4, (1) is a brush holder, and (2) is a brush inserted into the brush holder (1). As shown in the figure (
In the brush holder of 1), one or more pairs of holes (14) are drilled in the longitudinal direction of the brush holder on opposing sides, and one or more pairs of optical fibers are inserted directly or through a joint so as to face each other. and fix it.

One end of these optical fibers is connected to one light source α9, and the opposite end of the optical fiber 03) is connected to a photodetector display device 6).

If the light source 09 is turned on when the rotating electric machine is operating, the light will be blocked by the brush (2) or the brush (2) will be blocked in the initial stage.
As the brush length becomes shorter due to wear of the rotating current collector (
The light from the optical fiber a (to) on the opposite side of lη is released from the blocking state by the brush and is transmitted to the opposing optical fiber α3), which is detected by the light detection indicator (
16) so that the amount of wear can be detected. Furthermore, if multiple pairs of optical fibers (lalY) are provided, as the wear progresses, the second and third optical fibers on the opposite side of the rotating current collector (17) will become conductive, which will easily reduce the amount of wear on the brush. Therefore, by knowing the temporal liquefaction of brush wear, it is possible to predict in advance when it is time to replace the brush.Also, when using a large number of brushes, the light source αm Since only one circuit abnormality detection device (121) is required, the circuit becomes simpler.Also, since it can be installed in a quiet place away from the brush holder, which has a lot of light trace vibration, its life is significantly extended. A stable detection device that can withstand long periods of operation can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to know a small number of light sources and the Europeanization of the detection time, and thereby, when the brush father is replaced, J41j
It becomes possible to predict the future.

[Brief explanation of drawings]

The 11th is a plan view of a conventional rotating electric machine brush wear detection device;
FIG. 2 is a partially broken side view of the first cause, FIG. 3 is a circuit diagram corresponding to FIG. The figure is a partially cutaway side view of FIG. 4, and FIG. 6 is a circuit diagram corresponding to FIG. 4. l... Brush holder 2... Brush 13... Optical fiber 15... Light source 16... Light detection indicator. Agent Patent Attorney Rule Yu Chika (one idiot) Figure 1 Figure 2 Figure 2 / Figure 3 Figure 4 / Figure 5 Figure 6

Claims (1)

[Claims] A holder that is slidably held in the holder, a pair of optical fibers that are embedded in opposite side walls of the holder and have their cut ends open on the inner surface of the side walls, and a light trail that is connected to the other end of the optical fiber. A brush abrasion detection device for a rotating electrical machine, characterized by comprising a photodetector and a photodetector.