JP2000258305A - Diagnostic apparatus for abnormality of bearing part in rotating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To diagnose the part or the like of an abnormality cause by a method where in generated Lissajous waveform figures based on a vibration waveform signal are compared with every reference Lissajous waveform figure which is set already. SOLUTION: A vibration which is generated in the mounting position of a shaft due to the rotating drive of a motor is detected by both vibration detecting elements 1, 2. Vibration waveform signals of the detected vibration are outputted sequentially to a vibration detecting means 4. The signals are inputted to a Lissajous waveform- figure generation means 5, and Lissajous waveform figures are generated on the basis of both vibration waveform signals. On the other hand, a reference Lissajous waveform- figure generation means 6 previously sets and stores reference Lissajous waveform figures in a normal state and a plurality of reference Lissajous waveform figures which are assumed on the basis of every abnormality cause. Then, an abnormality- cause judgment means 7 compares the generated Lissajous waveform signals with every reference Lissajous waveform figure. When the generated Lissajous waveform figures are similar to any of reference Lissajous waveform figures which are not normal, it is judged that an abnormality is due to a cause according to the similar reference Lissajous waveform figures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a generator,
The present invention relates to an apparatus for diagnosing abnormality of a bearing of a rotating device, which diagnoses an abnormality of a bearing of a rotating device such as an electric motor.

[0002]

2. Description of the Related Art As a conventional abnormality diagnosis apparatus of this kind, for example, in Japanese Patent Application Laid-Open No. Hei 3-221818, a detection signal of the vibration of a rolling bearing detected by a vibration acceleration sensor is used. Natural frequency,
Pass each band pass filter having the natural frequency of the inner ring, the natural frequency of the outer ring, and the natural frequency of the bearing housing, perform envelope conversion on each of them, perform frequency conversion, and check for the occurrence of peeling that occurs on the inner and outer rings. When there is no characteristic frequency of peeling, it is determined that there is play between the bearing outer ring and the housing by comparing with the rotation frequency, and abnormal vibration of the cage based on the presence or absence of a temporal correlation with the vibration displacement waveform, It is disclosed that the type of the cause of the abnormality is diagnosed by discriminating and diagnosing the cage vibration or the like due to bearing falling.

[0003]

The conventional abnormality diagnosis apparatus diagnoses an abnormality by comparing the frequency of the vibration detected as described above with the frequency of the normal state. Can be diagnosed, but it is not possible to diagnose the cause of the abnormality.For example, when diagnosing the bearings of a large number of rotating equipment, if multiple abnormalities are diagnosed, it is diagnosed as abnormal. Since it is necessary to separate the bearing part of each rotating device and check the location, there is a problem that the work becomes complicated, and it is possible to diagnose abnormalities from sudden asynchronous abnormal waveforms. There was a problem that it was not possible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is a rotating device capable of diagnosing a cause of an abnormality and diagnosing an abnormality from a sudden asynchronous abnormal waveform. It is an object of the present invention to provide a device for diagnosing abnormality of a bearing portion.

[0005]

According to a first aspect of the present invention, there is provided an apparatus for diagnosing an abnormality in a bearing of a rotating device, comprising: a rotating device; Vibration detection means for detecting each vibration and outputting a vibration waveform signal; Lissajous waveform diagram generation means for generating a Lissajous waveform diagram based on both vibration waveform signals output by the vibration detection device; and A reference Lissajous waveform diagram setting means for presetting and storing a plurality of reference Lissajous waveform diagrams assumed respectively, and a Lissajous waveform diagram generated by the Lissajous waveform diagram generating means and a reference Lissajous waveform diagram setting means to be stored. An abnormality cause determining means for comparing the reference Lissajous waveform diagram to determine the cause of the abnormality and outputting the result.

According to a second aspect of the present invention, there is provided a device for diagnosing an abnormality in a bearing of a rotating device, wherein the vibration of a predetermined position of a shaft of the rotating device is detected.

According to a third aspect of the present invention, there is provided an abnormality diagnosis apparatus for a rotating device bearing, wherein each of the vibrations at both ends of the shaft is detected.

According to a fourth aspect of the present invention, there is provided an apparatus for diagnosing an abnormality of a bearing of a rotating device, wherein the result of the abnormality diagnosis is displayed on a display means. .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an apparatus for diagnosing abnormality of a rotating device bearing unit according to Embodiment 1 of the present invention, FIG. 2 is a diagram showing an attached state of a vibration detecting element in FIG. 1, and FIG. 3 is a reference Lissajous in FIG. It is a figure which shows each reference Lissajous figure set and stored in a waveform figure setting means.

In the figure, reference numerals 1 and 2 denote both shafts 3 of an electric motor 3.
a, a predetermined position on at least two axes orthogonal to each other on the same plane about the axis of one axis 3a of
A pair of vibration detecting elements, such as non-contact displacement sensors, which are attached to the outer peripheral surface of the shaft 3a at 90 ° intervals in the circumferential direction, and 4 is a vibration waveform of the vibration detected by each of the vibration detecting elements 1 and 2. Vibration detecting means 5 for outputting a signal are Lissajous waveform chart generating means for generating a Lissajous waveform chart based on the two vibration waveform signals output by the vibration detecting means 4.

Reference numeral 6 denotes a reference Lissajous waveform diagram setting means for presetting and storing a plurality of reference Lissajous waveform diagrams respectively assumed based on the cause of each abnormality, as shown in FIG. The Lissajous waveform diagram generated in step (1) is compared with each reference Lissajous waveform diagram stored in the reference Lissajous waveform diagram setting means 6 to determine and output the cause of the abnormality. This is display means for displaying the result of the abnormality diagnosis determined by the means 7.

Next, the operation of the apparatus for diagnosing abnormality of a bearing for a rotating device according to the first embodiment of the present invention will be described. First, when the electric motor 3 is driven to rotate, the two vibration detecting elements 1 and 2 start detecting vibration generated at the position where each of the shafts 3a is attached, and the vibration waveform signal of the detected vibration is used for vibration detection. Means 4 are sequentially output. The two vibration waveform signals thus output are input to the Lissajous waveform generating means 5, and a Lissajous waveform diagram is generated based on the two vibration waveform signals.

On the other hand, the reference Lissajous waveform diagram setting means 6 includes a reference Lissajous waveform diagram in a normal state and a plurality of reference Lissajous waveform diagrams respectively assumed based on the cause of each abnormality, as described below. 3 are set and stored, respectively. That is, when there is no abnormality in the bearing portion, a circular Lissajous waveform diagram having an appropriate size is generated as shown in FIG. 3 (A). Set the reference Lissajous waveform diagram of. Note that this waveform mainly shows the centrifugal force generated in the rotor when the motor 3 rotates,
This corresponds to the amount of elastic deformation between the balls of the rolling bearing and the inner and outer races caused by a slight inclination between the bearings supporting the bearings a and 3b.

If an excessive centrifugal force is generated in the shaft due to deterioration of the balance of the rotating rotor, the amount of elastic deformation between the balls of the rolling bearing and the inner and outer rings becomes larger than in the normal state, and the Lissajous waveform becomes normal. As shown in FIG. 3B, a circular Lissajous waveform having a larger diameter than a normal Lissajous waveform is set as a reference Lissajous waveform chart in a state in which the rotor is not well-balanced, as shown in FIG. .

If the spring for applying pressure between the ball of the rolling bearing and the inner and outer rings cannot operate normally and the applied pressure is smaller than a required set value, the amount of elastic deformation between the ball and the inner and outer rings is reduced. As the Lissajous waveform becomes smaller and the non-synchronous behavior of the Lissajous waveform becomes larger than in the normal state, the waveform having the non-synchronous behavior as shown in FIG. Set with figure.
Although not illustrated, when an asynchronous behavior exists in a part of the waveform, a position where the preload is missing can be specified by this position.

If the coaxiality between the bearing and the housing is poor, the posture between the two bearings supporting the two shafts 3a and 3b is poor, and the outer ring of the bearings is inclined, and the circumferential direction of the shaft is reduced. Since the rigidity changes depending on the position, the Lissajous waveform has an elliptical shape. As shown in FIG. 3D, there is an abnormality in the mounting of the bearing, such as deterioration of the coaxiality between the bearing and the housing. Set the reference Lissajous figure of the state. Although not shown, the direction of the bearing posture can also be specified from the directions of the major axis and the minor axis of the ellipse.

If there is a gap between the bearing and the housing,
Since the outer ring of the bearing moves with the rotation, the Lissajous waveform becomes a circular shape having a projection partly. Therefore, as shown in FIG. Set a reference Lissajous figure with a gap between the housings. The gap shape can also be predicted from the state in which the Lissajous waveform projection is formed.

Further, when the bearing is not arranged at the center and the coaxiality between the stator and the rotor is deteriorated, a radial force component having a period corresponding to the number of poles of the stator and the rotor is exerted on the shaft, so that the Lissajous waveform Has a petal shape,
Since the number of the petals is the same as the period of the radial force component, a petal-shaped waveform is set as a reference Lissajous waveform chart in a state where the bearing is not arranged at the center as shown in FIG.

Then, the abnormality cause determination means 7 generates a Lissajous waveform diagram generated by the Lissajous waveform generation means 5,
The reference Lissajous waveform charts set and stored in the reference Lissajous waveform chart setting means 6 as described above are compared with each other, and the Lissajous waveform chart is selected from the reference Lissajous waveform charts shown in FIGS. 3B to 3F. If it is similar to the above, it is diagnosed and output as an abnormality due to a cause corresponding to the similar reference Lissajous figure, and is displayed by the display means 8.

As described above, according to the first embodiment, the two vibrations detected by the pair of vibration detecting elements 1 and 2 mounted on the outer peripheral surface of the shaft 3a at 90 ° intervals on the circumference. Lissajous waveform generating means 5 based on the waveform signal
A Lissajous waveform diagram is generated, and the Lissajous waveform diagram is set in the reference Lissajous waveform diagram setting means 6 and compared with each of the stored reference Lissajous waveform diagrams. Since it is diagnosed as an abnormality caused by a similar reference Lissajous waveform diagram, it is possible to diagnose not only the type of the cause of the abnormality of the bearing portion, but also the part of the cause of the abnormality, and In addition, it is also possible to diagnose abnormalities from sudden asynchronous abnormal waveforms.

The pair of vibration detecting elements 1 and 2 need not necessarily detect the vibration of the shaft 3a.
The vibration of the side surface, mounting base, etc. of the shaft may be detected, but the behavior of the shaft includes not only mechanical vibration such as bearing abnormality, shaft eccentricity, curling, poor balance, but also imbalance of air gap, Since magnetic vibrations such as groove harmonics and vibrations due to drive signals appear directly, attachment to the shaft 3a also has the effect of easily specifying the cause of the abnormality.

Further, by displaying the result of the abnormality diagnosis on the display means 8, the cause of the abnormality can be easily transmitted to the operator. However, the present invention is not limited to this. It goes without saying that the abnormality may be transmitted.

Embodiment 2 FIG. FIG. 4 is a diagram showing an attached state of a vibration detecting element of the abnormality diagnosis device for a rotating machine bearing unit according to a second embodiment of the present invention. FIG. 5 is set and stored in a reference Lissajous figure diagram setting unit in FIG. FIG. 8 is a diagram showing a reference Lissajous waveform diagram different from that shown in FIG. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the second embodiment, as shown in FIG. 4, a pair of vibration detecting elements 9 and 10 are connected to both shafts 3 of electric motor 3.
a and 3b are mounted on the same axis in the circumferential direction, and the two vibrations detected by the two vibration detection elements 9 and 10 are output as vibration waveform signals by the vibration detection means 4 in the same manner as in the first embodiment. A Lissajous waveform diagram is generated by the Lissajous waveform generating means 5 based on these two vibration waveform signals, and the Lissajous waveform diagram is compared with the set and stored reference Lissajous waveform diagram by the reference Lissajous waveform setting means 6 to determine the abnormal state. A diagnosis is made.

Here, the reference Lissajous waveform chart set and stored by the reference Lissajous waveform setting means 6 will be described. When the two vibration detection elements 9 and 10 are attached as described above, the Lissajous waveform of the axis behavior in a normal state has an elliptical shape in which each axis operates in the same phase as shown in FIG. If the balance between both ends of the rotor is not correct, the radial forces acting on the bearings supporting the two shafts 3a and 3b are different. Since the directions of the major axis and the minor axis have an inclination compared to the normal state, FIG.
A waveform having an inclination in the direction of the major axis and minor axis of the ellipse as shown in (C) is set as a reference Lissajous waveform chart in which both ends of the rotor are unbalanced. The axis on which the load is applied is specified by the direction in which the waveform is inclined, and the direction of the rotor balance can be predicted.

In each of the first and second embodiments, the electric motor 3
However, the present invention is not limited to this, and it is needless to say that the present invention can be applied to abnormality diagnosis of a bearing portion of another rotating device such as a generator.

[0027]

As described above, according to the first aspect of the present invention, vibrations are detected at predetermined positions on at least two axes orthogonal to each other on the same plane about the axis of the rotating device. A vibration detection unit that outputs a waveform signal; a Lissajous waveform diagram generation unit that generates a Lissajous waveform diagram based on the two vibration waveform signals output by the vibration detection unit; A reference Lissajous waveform diagram setting means for presetting and storing a reference Lissajous waveform diagram, and a comparison between the Lissajous waveform diagram generated by the Lissajous waveform diagram generating device and each reference Lissajous waveform diagram stored in the reference Lissajous waveform diagram setting device Abnormality judgment means for judging the cause of the abnormality and outputting the result. Can provide diagnostic and troubleshooting apparatus sudden abnormality diagnosis is possible rotating equipment bearing portion from asynchronous nature of the abnormal waveform.

According to a second aspect of the present invention, in the first aspect, the vibration at a predetermined position of the shaft of the rotating device is detected, so that the cause of the abnormality can be easily specified. An abnormality diagnosis device can be provided.

According to a third aspect of the present invention, in the second aspect, since each vibration at both ends of the shaft is detected, a rotating device capable of diagnosing imbalance at both ends of the rotor. An apparatus for diagnosing abnormality of a bearing portion can be provided.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the result of the abnormality diagnosis is displayed on the display means, so that the cause of the abnormality can be easily notified to the operator. An apparatus for diagnosing an abnormality in a bearing of a rotating device capable of transmitting the information can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an apparatus for diagnosing abnormality of a rotating device bearing unit according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing an attached state of a vibration detecting element in FIG.

3 is a diagram showing each reference Lissajous figure set and stored in a reference Lissajous figure setting means in FIG. 1;

FIG. 4 is a diagram showing an attached state of a vibration detecting element of the abnormality diagnostic device for a rotating device bearing unit according to the second embodiment of the present invention.

5 is a diagram showing a reference Lissajous waveform diagram different from that shown in FIG. 3 which is set and stored in the reference Lissajous waveform diagram setting means in FIG. 1;

[Explanation of symbols]

1, 2, 9, 10 Vibration detecting elements, 3 motors (rotating equipment), 3a, 3b axes, 4 vibration detecting means, 5 Lissajous waveform diagram generating means, 6 reference Lissajous waveform diagram setting means, 7 abnormality diagnosing means, 8 display means.

Continued on the front page (72) Inventor Yuji Nakahara 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) in Mitsubishi Electric Corporation 2G024 AD22 BA11 BA22 BA27 CA13 DA09 FA06 FA11

Claims (4)

[Claims] 1. A vibration detecting means for detecting vibrations at predetermined positions on at least two axes orthogonal to each other on the same plane about an axis of a rotating device and outputting a vibration waveform signal; Lissajous waveform diagram generating means for generating a Lissajous waveform diagram based on both output vibration waveform signals, and a reference Lissajous waveform for presetting and storing a plurality of reference Lissajous waveform diagrams respectively assumed based on the cause of each abnormality An abnormality cause for comparing the Lissajous waveform diagram generated by the Lissajous waveform diagram generation device with each of the reference Lissajous waveform diagrams stored in the reference Lissajous waveform diagram setting device to determine and output the cause of the abnormality; An apparatus for diagnosing abnormality of a bearing of a rotating device, comprising: a determination unit. 2. The apparatus for diagnosing abnormality of a bearing of a rotating device according to claim 1, wherein vibration of a predetermined position of a shaft of the rotating device is detected. 3. The apparatus for diagnosing abnormality of a bearing of a rotating device according to claim 2, wherein each vibration at both ends of the shaft is detected. 4. The apparatus for diagnosing abnormality of a bearing of a rotating device according to claim 1, wherein the result of the abnormality diagnosis is displayed on a display means.