JPS6181155A - Chattering diagnosing method of brush - Google Patents

Abstract

PURPOSE:To early discover effectively the occurrence of a chattering by detecting by a microphone a noise near a brush, converting it into an electric signal to diagnose the presence or absence of the chattering from a distribution pattern of the frequency spectrum of the signal. CONSTITUTION:The chattering of a brush 2 contacted with a commutator or a current collecting ring 1 of a rotary electric machine is diagnosed, and a microphone 3, a frequency analyzer 4 and a display unit 5 are provided. Thus, the level of the frequency spectrum entirely becomes large at chattering time as compared at that at normal time, and the distribution pattern of the spectrum is different. Accordingly, the output of the analyzer 4 is pattern-recognized by a computer, and an alarm signal is generated at nonnormal time pattern time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for diagnosing the presence or absence of chattering in the brushes of a rotating electric machine.

[Conventional technology]

If chattering occurs in the brushes of a rotating electrical machine during operation,
This may cause abnormal wear of the brushes, damage to the current collection ring and commutator due to the generation of sparks, and eventually lead to flashover, which may lead to an accident in the rotating electric machine.

[Problem that the invention seeks to solve]

For this reason, it is desirable to detect the occurrence of chattering as early as possible, but conventionally, it has been discovered by checking whether the brushes are broken or not and their behavior during periodic inspections, or by detecting abnormal noises during operation during daily inspections. In addition to delaying discovery, it also lacks accuracy because it relies on human vision, hearing, and touch.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a brush chattering diagnosis method that can detect brush chatter earlier and more accurately than in the past.

[Means for solving problems]

This invention is configured to pick up sounds near the brush with a microphone, analyze the frequency spectrum of the output of the microphone, and diagnose the presence or absence of brush chattering from its distribution and pattern.

[Effect]

In this invention, since a microphone is used as a sensor, the presence or absence of brush chatter can be constantly monitored, and since it is physically diagnosed, it is accurate.

〔Example〕

Fig. 1 is a component arrangement diagram for explaining one embodiment of the present invention, and Fig. 2 is a block diagram, in which 1 is a commutator or current collector ring of 11 rotating machines, 2 is a brush, 3 is a microphone, 4 is a frequency analyzer, and 5 is a display device.

Figures 3 and 4 show the frequency spectrum of the electrical signal sent out by the microphone 3. Figure 2 shows the frequency spectrum when chattering occurs in the brush 2, and Figure 3 shows the frequency spectrum when the brush is normal. This is a distribution diagram showing that when chattering occurs, the overall level is higher than when it is normal, and in particular, the frequency components in the high frequency range of 3000 Hz to 5000 Hz become larger. The distribution patterns of the frequency spectra are significantly different.

In this embodiment, this pattern is displayed on the display device 5 to diagnose whether or not chattering has occurred.

In addition, when performing automatic diagnosis, the output of the frequency analyzer 4 is configured to be pattern-recognized using a computer, and an alarm command signal is sent out if the output is an abnormal pattern. The level of the frequency component is compared with a predetermined set level that is higher than the normal level, and when the former is higher than the latter, an alarm signal is generated.

〔Effect of the invention〕

As explained above, this invention detects the noise near the brush with a microphone, converts it into an electrical signal, and diagnoses the presence or absence of chattering from the distribution pattern of the frequency spectrum, thereby detecting the condition of the brush. Since it is possible to constantly monitor the occurrence of chattering, the occurrence of chattering can be detected early and reliably, making it possible to improve the reliability of rotating electric machines and save labor on maintenance compared to the conventional method.

[Brief explanation of drawings]

1 and 2 are a microphone arrangement diagram and a block diagram, respectively, for explaining the present invention in detail, and FIGS. 3 and 4 are frequency spectrum distribution diagrams. In the figure, 2--brush, 3-microphone, 4--
...-Frequency analysis device, 5-Display device.

Claims (2)

[Claims] (1) A method for diagnosing brush chattering, in which a microphone is disposed near the brush of a rotating electrical machine, and the output of the microphone is frequency-analyzed to determine whether or not brush chattering has occurred based on the distribution pattern of the frequency spectrum. (2) The method for diagnosing a brush chattering rig according to claim 1, wherein the level of a specific frequency range is compared with a predetermined level and the presence or absence of occurrence of brush chatter is diagnosed based on the magnitude thereof.