JPS59116526A - Method for detecting abnormality of rolling bearing - Google Patents

Abstract

PURPOSE:To improve judging accuracy, by detecting the abnormality of a bearing based on a distribution pattern of the generated time interval of a signal, whose amplitude exceeds a threshold value in a sampling time from a trigger signal, with the signal, whose amplitude exceeds the threshold value as a trigger signal; extracting the signal only associated to the abnormality; and diagnosing the contents of the abnormality in detail. CONSTITUTION:A detecting device 1 is provided with a pulse forming circuit 2, a clock circuit 3, a counting circuit 4, an accumulating circuit 5, and a memory circuit 6. The pulse forming circuit 2 generates pulses when an input signal exceeds a preset voltage level (threshold value). The clock circuit 3 receives the pulses from the pulse forming circuit 2, operates a clock, stops the operation after a specified time, and repeats the procedure. The counting circuit 4 measures the generating time of the pulses formed in the pulse forming circuit 2. The accumulating circuit 5 accumulates the pulses measured in the counting circuit 4 at every generated time. The memory circuit 6 stores the accumulated result from the memory circuit 6 is the distribution of the generated time interval of the signal, whose amplitude exceeds the threshold value, among the signals generated from a rolling bearing. Based on the time interval distribution, presence of abnormality is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting an abnormality in a rolling bearing.

During operation of rolling bearings, acoustic vibrations or AE (acoustic emission) such as rolling bearings
) occurs as shown in Fig. 1, and the situation in which it occurs corresponds well to damage to the rolling bearing. For this reason, various abnormality detection methods have been developed that utilize such signals to detect abnormalities in rolling bearings. Examples of such abnormality detection methods include (a) r of vibration acceleration;

(b) determining the increase in the maximum amplitude value of vibration acceleration due to an abnormality, (e) processing the amplitude distribution in a systematic manner, There are methods to determine based on the pattern.

However, although the conventional abnormality detection method described above can detect that an abnormality has occurred in a bearing, it cannot specifically determine which part of the bearing has experienced an abnormality.

In addition, especially in the detection methods (a), (b), (c), and (e), signals related to abnormalities and signals related to abnormalities are all processed at the same time. There is a risk that signals caused by true abnormalities may be buried in the detection, making it difficult to improve detection accuracy.

This invention was made in view of the above circumstances, and uses signals caused by normal conditions to extract only signals related to an abnormality, and more specifically diagnoses the contents of the abnormality to improve the accuracy of judgment. It is an object of the present invention to provide a method for detecting abnormalities in rolling bearings that can easily improve the performance of rolling bearings.

Corresponding to this purpose, the rolling bearing abnormality detection method of the present invention triggers a signal with an amplitude exceeding a threshold value among the signals generated from the rolling bearing during operation of the rolling bearing to be tested. The present invention is characterized in that an abnormality in the bearing is detected based on the distribution pattern of the time interval at which a signal having an amplitude exceeding the threshold value is generated within the sampling unit 1' from the trigger signal.

The details of this invention will be explained below with reference to FIGS. 2 and 3 showing one embodiment.

FIG. 2 shows a detection apparatus used in carrying out the present invention. The detection device 1 includes a pulse circuit 2 and a clock circuit 3.
, a clock circuit 4, an accumulation circuit 5, and a memory circuit 6. The pulsing circuit 2 generates a pulse when the input signal exceeds a preset voltage level (threshold). The clock circuit 3 receives the pulse from the pulse generator 2, activates the clock, stops the operation after a certain period of time, and repeats this operation.The clock circuit 4 measures the generation time of the pulse generated by the pulse generator 2. The accumulation circuit 5 accumulates the pulses measured by the clock circuit 4 at each generation time.

The storage circuit 6 stores the accumulated results and outputs the stored contents.

The method for detecting an abnormality in a rolling bearing according to the present invention is carried out as follows using the abnormality detection equipment configured as described above.

Assume that a signal during operation, for example a vibration signal, from a rolling bearing to be tested is as shown in FIG. This signal is input to the pulsing circuit 2. The pulsing circuit 2 receives signals @P of the incoming horn signal that exceed a preset voltage level (threshold).

When P2, P3, . . . are input, the corresponding pulses p7 and call circles are generated. The clock circuit 3 operates the clock by using the pulse P1 of the pulses from the pulse generation circuit 2 as a 1-rigger signal, stops the operation after a certain thumbling time T has elapsed, and outputs the first pulse P1 after the stop, the pulse Set P4 to 1 to RIGA 1 signal and repeat the above operation. Next, the clock circuit 4 measures the generation time of the pulse from the pulsing circuit 2. That is, the time t(n-l') is measured from the start of time measurement for each pulse. Next, an accumulation circuit 5 accumulates the pulses measured by the timer circuit 4 for each generation time. This cumulative result is stored in the storage circuit 6 and output. In other words, the cumulative result outputted from the memory circuit 6 is the distribution of the generation time intervals of signals with amplitudes exceeding the threshold among the signals generated from rolling bearings. , as shown in FIG. This pattern is determined by the rotational speed and internal dimensions of the bearing, and therefore, based on the time interval distribution pattern, it can be determined that the abnormality is related to the inner ring (inner ring damage, pattern A) or the outer ring (outer ring damage, pattern B). , or it is related to the ball (damaged ball, pattern C), or it is just noise (
It can be determined whether the pattern is pattern D). In addition,
In general, it goes without saying that the above-mentioned pattern is unique and varies depending on the type and size of the bearing and the operating conditions.

In this way, with the abnormality detection method of the present invention, it is possible to determine that an abnormality has occurred in a bearing (not just a single part of the bearing), but also to determine specifically which part of the bearing has experienced an abnormality.
Unlike conventional detection methods, only the signals related to the abnormality are extracted and processed, rather than processing all signals related to the abnormality and signals unrelated to the abnormality, so there is no wasted processing. There is no fear that a signal caused by a true abnormality will be buried in noise, and it is easy to increase detection speed and detection accuracy.

The above explanation is about an embodiment in which an abnormality is detected using vibration on the back of a signal from a rolling bearing, but this invention can also utilize sound and AE in addition to vibration. .

[Brief explanation of drawings]

Figure 1 shows the signal output from the rolling bearing force mill.
Fig. 12 is a ten-dimensional diagram showing the configuration of the detection device, Fig. 3 is a graph showing the relationship between the signal output from the rolling 1111 receiver and the threshold value, and Fig. 4 is a graph showing the distribution pattern of the signal pulse generation time interval. . 1...Detection device 2...Pulsing circuit 3...
・Clock circuit 4...Time measurement circuit 5...Accumulation circuit 6...Memory circuit

Claims (1)

[Claims] Among the signals generated from the rolling bearing during operation of the rolling bearing to be tested, a signal with an amplitude exceeding the threshold 0 value is used as a trigger signal, and the pre-ffa threshold value is set within a sampling time from the trigger signal. 1. A method for detecting an abnormality in a rolling bearing, characterized in that an abnormality in the bearing is detected based on a distribution pattern of the time interval of occurrence of a signal with an amplitude exceeding .