JPH0367145A - Abnormality diagnostic device for gear - Google Patents

Abstract

PURPOSE:To diagnose the abnormality of the gear without misdiagnosis by detecting AE generated from a gear by a 1st AE sensor and a 2nd AE sensor and outputting an AE signal. CONSTITUTION:If the gear is abnormal, the abnormal part generates AE every time the abnormal part engages an opposite gear and the 1st AE sensor 1 and 2nd AE sensor 2 detect it. Then an abnormality decision means 35 decides the abnormality of the gear according to the output of a comparing means 13 or 23 which compare at least one of an AE signal a1' passed through a 1st band-pass filter 12 and an AE signal a2' passed through a 2nd band-pass filter 22 with a reference value S1 or S2, and the output of a ratio decision means 32 which decides whether or not the ratio value outputted by a ratio calculating means 30 for calculating and outputting the ratio of the signals a1' and a2' is within a constant range. When the means 32 decides that the ratio is within the constant range and the means 13 and 23 decide that the AE signals are larger than the reference values, it is decided that the gear becomes abnormal.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a gear abnormality diagnosis device.

<Conventional technology> Conventionally, gear abnormality diagnosis devices detect vibrations generated by gears using a vibration sensor installed in the gear drive device, and detect when the detected vibrations show an abnormal value exceeding a reference value. There is a device that determines that an abnormality has occurred in the above-mentioned gear.

<Problems to be Solved by the Invention> However, since the above-mentioned conventional gear abnormality diagnosis device determines the abnormality of the gear based on the vibration generated by the gear, when determining the abnormality, it is necessary to detect the abnormality caused when the gears mesh. There has been a problem in that misdiagnosis is often caused by the influence of disturbances such as vibrations and vibrations generated in the drive device.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a gear abnormality diagnosis device that can diagnose gear abnormalities without misdiagnosing them by determining whether AE is caused by an abnormality that occurs in the gear. .

<Means for Solving the Problems> In order to achieve the above object, the present invention provides that when a gear has an abnormality such as a scratch on the tooth surface or an internal crack on the inner side of both sides, this abnormal part is removed every time it meshes with a mating gear. AE is generated, and the generation of this AE becomes the rotational frequency of the gear, and furthermore, when this AE is detected by AE sensors installed at two locations, the ratio of the AE multiplied signal levels detected by these two AE sensors is , focusing on the fact that the value is constant depending on the length of the AE transmission path from the gear to each AE sensor. That is, the gear abnormality diagnosis device of the present invention detects the AE generated by the gear and outputs the AE multiplied signal.
A sensor and a second AE sensor, a first bandpass filter and a second bandpass filter that pass the rotational frequency component of the gear recorded in the AE multiplied signals from the first AE sensor and the second AE sensor, and the first bandpass filter. Ratio calculation means for calculating and outputting the ratio of the AE multiplied signal passed through the filter and the AE multiplied signal passed through the second bandpass filter, and whether or not the ratio value from the ratio calculation means is included in a certain range. a ratio determining means for determining the first
a comparison means for comparing at least one of the AE multiplied signal passed through the band pass filter or the AE multiplied signal passed through the second band pass filter with a reference value; and the ratio judgment based on the outputs of the comparison means and the ratio judgment means. The means determines that the value of the ratio is within a certain range, and the comparison means determines that A
The present invention is characterized by comprising an abnormality determining means that determines that an abnormality has occurred in the gear when it is determined that the E times signal is larger than the reference value.

<Operation> If a gear has an abnormality such as scratches on the tooth surface or internal cracks, this abnormal part will generate AE every time it meshes with a mating gear. Therefore, the first AE sensor and the second AE sensor
AE from the abnormal part/minute detected by the sensor and output
The multiplied signal has the rotational frequency of the gear. Also, 1st A
Detected by the E sensor and the second AE sensor, and the first
The respective AE multiplied signal level ratios from which components other than the rotational frequency components of the gear are removed by the band-pass filter and the second band-pass filter are
．． The value of the ratio corresponds to the length of the transmission path up to the 2AE sensor.

The abnormality determining means includes an output from a comparing means for comparing at least one of the AE multiplied signal passed through the first band pass filter and the AE multiplied signal passed through the second band pass filter with a reference value; 2. Determine whether the ratio value from the ratio calculation means that calculates and outputs the ratio of the AE multiplied signal that has passed through the second band pass filter is within a certain range. Based on the output of the ratio determining means, abnormality of the gear is determined.

When the ratio determining means determines that the ratio value is within a certain range and the comparing means determines that it is larger than the AE multiplication signal reference value, it is determined that an abnormality has occurred in the gear.

The above-mentioned certain range, which is the judgment criterion of the above-mentioned ratio judgment means, is based on the distance from the gear to the first AE sensor and the distance from the gear to the second AE sensor.
Based on the distance to the E sensor, etc., an appropriate range is set in advance so that the ratio value from the ratio calculation means when the AE generation source is a gear is included within the range as necessary and sufficient. Therefore, the fact that the ratio determining means determines that the ratio value from the ratio calculating means is within this certain range means that the source of the AE detected by the 1.2 AE sensor is the gear. do. On the other hand, the reference value, which is a comparison standard for the AE multiplied signal in the comparison means, is set in advance to an appropriate value so that it can be determined whether or not the AE is caused by the presence of an abnormality. Therefore, the comparison means determines that the AE multiplied signal is larger than the reference value.
This AE means that it occurs due to the presence of an abnormality. Therefore, when the above-mentioned abnormality determining means establishes a logical product between the fact that the AE generation source is a gear and the fact that this AE is generated due to the presence of an abnormality,
It is determined that the detected AE is an AE caused by the presence of an abnormality occurring in the gear, that is, an abnormality has occurred in the gear.

In this way, based on the AE detected by the first AE sensor and the second AE sensor, it is determined that the AE is caused by the gear and that the AE is caused by the presence of an abnormality.
Since it is determined that there is an abnormality in the gear only when the two conditions of E are satisfied, the abnormality in the gear can be reliably detected. There is no misdiagnosis like in the past.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a block diagram showing a gear abnormality diagnosing device according to the present invention.

In FIG. 1, 1 is a first AE sensor, and 2 is a second AE sensor. As shown in FIG. 2, the first AE sensor (2) and the second AE sensor (2) are provided integrally with the gear 3 in order to diagnose whether or not there is an abnormality in the gear 3. The bearings 5 and 6 are respectively attached to bearings 5 and 6 that support the shaft 4 which is supported at the position shown in FIG. And this first
The AE sensor 1 and the second AE sensor 2 detect that the gear 3 has an abnormality such as a scratch on the tooth surface or an internal crack.
If AE is generated when meshing with the mating gear 7, the AE caused by this abnormal portion can be reliably detected.

AE multiplied signal 1 detected and output by the first AE sensor 1
is amplified by the first amplifier lO, envelope-detected by the first envelope detection circuit 2, and then passed by the first band-pass filter 12, where only the component of the rotational frequency f of the second gear 3 is passed. In this way, this first band-pass filter 12 passes only the component of the rotational frequency of the gear 3 (the same applies to the second band-pass filter 22 described later). The AE multiplied signal l from which frequency components other than the rotational frequency f of the gear 3 have been removed by passing through is manually input to the first comparison circuit 13 as comparison means and the ratio calculation circuit 30 as ratio calculation means. The AE multiplied signal detected and outputted by the second AE sensor 2 is amplified by the second amplifier 20, envelope-detected by the second envelope detection circuit 2!, and then sent to the second band-pass filter 22. As a result, only the component of the rotational frequency r of the gear 3 is made incidental.Then, the AE multiplied signal, °, which has passed through this first bandpass filter is sent to the second comparison circuit 23 as comparison means and the ratio calculation circuit 30. Man-powered.

The first comparison circuit I3 compares the AE multiplied signal + passed through the first bandpass filter 12 with a reference value S1,
When this AE multiplied signal + exceeds the reference value S1, a signal indicating this is input to the OR circuit 3. Also, like the second comparison circuit 13, the second comparison circuit 23 compares the AE multiplied signal l passed through the second band-pass filter with the reference value S, and the AE multiplied signal 1 exceeds the reference value St. When the value exceeds the above, the OR circuit 30 outputs a signal C indicating this fact. When the OR circuit 31 receives at least one of the signals S and C, it inputs a signal d indicating this to the ANDN path 33.

On the other hand, the ratio calculation circuit 30 calculates the AE multiplied signal 1' from the first bandpass filter 12 and the AE multiplied signal from the second bandpass filter 22.

Calculate the ratio between Then, the ratio value N as the calculation result
A ratio signal e indicating the ratio is input to a ratio determination circuit 32 serving as a ratio determination means. Since AE attenuates at a nearly constant rate per unit transmission length, the value N of this ratio is determined by
It becomes a constant value depending on the length of the transmission path (see arrow in FIG. 2) to the AE sensor 1 and to the second AE sensor 2, respectively.

The ratio determination circuit 32 that receives this ratio signal e determines whether the ratio value N indicated by the ratio signal e is included in the reference range R, and determines whether the ratio value N indicated by the ratio signal e is within the reference range R. , a signal g indicating this is input to the ANDN path 33.

This ANDN path 33 sends a signal indicating this, that is, an abnormal signal, to the display device 36 when the signal d is input from the OR circuit 3■ and the signal g is input from the ratio judgment circuit 32. do.

The ANDN path 33 and the OR circuit 31 constitute an abnormality determining means 35. That is, when the abnormality determining means 35 receives a signal output from the first comparison circuit 13 indicating that the AE multiplied signal 1° exceeds the reference value SI, the abnormality determination means 35 outputs the AE multiplied signal from the second comparison circuit. , ° exceeds the reference value SI, signal C, and the above AE double signal,
Based on the ratio signal e from the ratio calculation circuit 30 that calculates the ratio between + and AE double signal at', at least one of AE double signal + and AE double signal l exceeds the respective reference value S1 or reference value SI, Further, when the value N of the ratio between the AE double signal a+" and the AE double signal t" is included in the reference range R, an abnormality signal indicating that the gear to be diagnosed is abnormal is sent to the display device 36. Then, the display device 36 displays that there is an abnormality in the gear 3 being diagnosed.

In the above configuration, it is assumed that one of the plurality of teeth of the gear 3 shown in - has an abnormality such as a scratch on the tooth surface or an internal crack (see p in FIG. 2). It is assumed that this gear 3 is rotating at a rotational frequency f while meshing with a mating gear 7. Then, the abnormal portion generates AE every time the tooth where the abnormal portion is located meshes with the tooth of the mating gear 7. Therefore, it is detected by the first AE sensor 1, and the first
The AE multiplied signal 1 whose envelope was detected by the envelope detection circuit and the AE multiplied signal detected by the second AE sensor and whose envelope was detected by the second envelope detection circuit both have the rotation frequency r of the gear 3. . Therefore, the AE double signal l and the AE double signal at' pass through the first band pass filter I2 and the second band pass filter 22, respectively, and as described above, the first comparison circuit 13, the J'2 comparison circuit 23, and the second band pass filter 22, respectively. It is input to the ratio calculation circuit 30. AE multiplied signal other than rotational frequency r This first band pass filter 1
2 and the second bandpass filter 22, and the first comparison circuit 13. It is not input to the second comparison circuit 23 and the ratio calculation circuit 30.

In other words, this first bandpass filter 12 and the second bandpass filter
The band-pass filter 22 removes noise that may lead to misdiagnosis of gear abnormalities.

The first comparison circuit above! 3 and the second comparison circuit 23, the reference value SI and the reference value SI are respectively 1.2AE
The magnitudes of the AE multiplied signals lrat detected by the sensors 1 and 2 are set in advance to appropriate values so that it can be accurately determined whether or not they are generated due to the presence of an abnormality. That is, the first comparison circuit 13 and the second comparison circuit 2
In step 3, it is determined whether or not the abnormality is caused by the presence of an abnormality in the AE multiplied signal that is manually input. Therefore, here, the AE double signal I that has passed through the first band pass filter 12 and the AE double signal 2° that has passed through the second band pass filter 22 are the reference value S1 and the reference value SI, respectively.
exceed. Therefore, the signal from the first comparison circuit 13 is
Further, the signal C is input from the second comparison circuit 23 to the OR circuit 31, and the OR circuit 31 inputs the signal d to the ANDN path 33. At least one of the first comparison circuit I3 and the second comparison circuit 23 outputs the signal C or the signal C.
This means that it is caused by the presence of an AE double signal abnormality.

On the other hand, the reference range R, which is the judgment standard of the ratio judgment circuit 32,
is the occurrence of AE based on the distance M from the gear 3 to the first AE sensor 1 (see Q, l in Figure 2) and the distance from the gear 3 to the second AE sensor 2 (see Q, in Figure 2). tl! so that the value N of the ratio of the ratio signal e from the ratio calculation circuit 32 when the source is the gear 3 is included within its range as necessary and sufficient. 6 It is set within an appropriate range. In other words,
'' The binary ratio determination circuit 30 determines whether or not the gear 3 is the source of AE. Even if AE occurs in a part other than the gear 3, in that case, the ratio signal e from the ratio calculation circuit 30
Since the ratio value N indicated by is not within the reference range R, the ratio determination circuit 32 does not output the signal g.

In this way, for the ratio calculation circuit 30 to determine that the value N of a given ratio is within this certain range R, that is, for the ratio determination circuit 32 to output the signal g, the above 1.2AE
Note that the source of AE detected by sensors 1 and 2 is gear 3. Here, the ratio calculation circuit 30 calculates the AE doubling percentage and the AE doubling signal t1 due to the presence of an abnormality.
．． Therefore, the ratio value N indicated by the ratio signal e from the ratio calculation circuit 30 is included in the reference range R. Therefore, the ratio determination circuit 32 inputs a signal g indicating this to the ANDN path 33. Therefore, the ANDN which receives this signal g and the signal d from the OR circuit 31
The line 33 sends out an abnormality signal to cause the display device 36 to indicate that there is an abnormality. In this way, the OR circuit 31 and the AN
The above-mentioned abnormality determining means 35, which is composed of a DN path 33, is
The detected AE occurs in the gear only when the logical product of the fact that the source of E is the gear and that the AE is caused by the presence of an abnormality is established, and the detected AE is caused by the presence of the abnormality. In other words, it is determined that the gear 3 is abnormal.

In this way, according to this gear abnormality diagnosis device, the first A
AE detected by E sensor 1 and second AE sensor 2
Based on this, it is determined that there is an abnormality in the gear only when two conditions are met: the AE originates from the gear, and the AE occurs due to the presence of an abnormality. If there is an abnormality in the gear, it can be detected reliably and immediately. There is no misdiagnosis like in the past.

When gear abnormalities were diagnosed based on vibration, it could not be determined that there was an abnormality unless the abnormality was quite large, but since abnormalities are diagnosed based on AE, even minute abnormalities can be detected. It is possible to reliably diagnose that there is an abnormality without missing anything.

In the above embodiment, the first comparison circuit 13 and the second bandpass filter 22 are used as comparison circuits to compare the AE multiplied signal + passed through the first bandpass filter 12 with the reference value SI.
The second AE multiplied signal, °, which has passed through the reference value SI, is compared with the reference value SI.
A comparison circuit 23 is provided, and an OR circuit 31 which takes the logical sum of the output from the first comparison circuit 13 and the output C from the second comparison circuit 23, and an output d from the OR circuit 31 and a ratio determination circuit 32. ANDN path 3 which takes the logical product of the output g of
3 constitutes the abnormality determination means 35, but in addition to providing a comparison circuit for comparing either the AE multiplied signal passed through the first band pass filter or the AE multiplied signal passed through the second band pass filter with a reference value, The abnormality determination means may be constituted by an AND circuit that takes the logical product of the output from the comparison circuit and the output from the ratio determination circuit. The operation and effect are the same as in the above embodiment.

Further, in the above embodiment, the first band pass filter 12 and the second band pass filter pass through the component of the rotational frequency f of the AE multiplied signal generated by the gear 3 and detected by the first AE sensor l and the second AE sensor 2. A filter 22 is provided, and the abnormality diagnosis of the gear 3 is performed based on the AE multiplied signal, °, mm ° that has passed through the 11.2 band-pass filter 12.22.
Analyze the frequency of each AE multiplied signal detected by the E sensor, and based on the power value at the rotation frequency of the gear as a result of the analysis,
An abnormality diagnosis of the gear may also be performed.

<Effects of the Invention> As is clear from the above, the gear abnormality diagnosing device of the present invention uses the abnormality determining means to detect the AE multiplied signal that has passed through the first band pass filter or the AE multiplied signal that has passed through the second band pass filter. an output from a comparison means that compares at least one of the signals with a reference value to determine whether or not the AE is an AE caused by the presence of an abnormality; and the second AE multiplied signal that has passed through the first bandpass filter. It is determined whether the ratio value from the ratio calculation means that calculates and outputs the AE multiplied signal ratio that has passed through the bandpass filter is within a certain range, and whether the AE generation source is the AE generated by the gear. The ratio determining means determines that the value of the ratio is within a certain range based on the output of the ratio determining means, which determines whether
When the source of the AE is determined to be a gear, and the comparison means determines that the AE multiplier signal is larger than the reference value, that is, the AE is determined to be caused by the presence of an abnormality,
It is determined that an abnormality has occurred in the gear. Therefore, according to this gear abnormality diagnosis device, it is possible to accurately diagnose a gear abnormality. There is no misdiagnosis like in the past.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the gear abnormality diagnosis device of the present invention, and FIG. 2 is an explanatory diagram of the arrangement of the 1.2 AE sensor. l...first AE sensor, 2...second AE sensor, 3
...lL12...first band pass filter 13.
...First comparison circuit, 22...Second band pass filter 23...Second comparison circuit, 3o...Ratio calculation circuit, 32
... Ratio judgment circuit, 35... Abnormality judgment means, a, ,
a, -A E signal, a,... AE double that has passed through the first band pass filter, a,... AE double that has passed through the second band pass filter, b... AE double signal that has passed through the second band pass filter, b... AE double signal that has passed through the first band pass filter. Output signal, C... Output signal of the second comparison circuit, g... Output signal of the ratio judgment circuit, h... Abnormal signal, S
,, Sl...Reference value, R...Reference range.

Claims (1)

[Claims] (1) A first AE sensor and a second AE sensor that detect AE generated by the gear and output an AE signal; and a rotation frequency component of the gear in the AE signals from the first AE sensor and the second AE sensor is passed through. 1st
a bandpass filter and a second bandpass filter; a ratio calculation means for calculating and outputting a ratio between the AE signal that has passed through the first bandpass filter and the AE signal that has passed through the second bandpass filter; ratio determining means for determining whether the ratio value from the means is within a certain range; and at least one of the AE signal that has passed through the first band pass filter or the AE signal that has passed through the second band pass filter. a comparison means for comparing with a reference value, and based on the outputs of the comparison means and the ratio determination means, the ratio determination means determines that the value of the ratio is within a certain range,
A gear abnormality diagnosing device comprising: abnormality determining means for determining that an abnormality has occurred in the gear when the comparison means determines that the AE signal is larger than a reference value.