JPH0843257A - Method for diagnosing planetary gear - Google Patents

Abstract

PURPOSE:To enable an unskilled person to easily identify the kind, part, and degree of the damage of a planetary gear mechanism at the time of diagnosing the kind and part of the damage of the mechanism by allowing the person to accurately detect the kind, part, and degree of the damage. CONSTITUTION:A vibration detecting section 54 which detects each specific frequency generated when each section of a planetary gear mechanism is rotated and a diagnosis processing section which automatically diagnoses the kind and part of each damage and each specific frequency by correlating them with each other based on a diagnostic rule, are provided near the planetary gear mechanism. The diagnosis processing section extracts the detecting signals of the specific frequency and higher-order frequencies detected by the detecting section 54 and calculates the values respectively corresponding to the initial values of the specific and higher-order frequencies and, when the corresponding values are higher than reference values, specifies the kind, part, and degree of the corresponding breakage and displays the name of the breakage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing a planetary gear, which is for diagnosing the type, location and degree of damage to the planetary gear.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 168518/56 and Japanese Patent Application Laid-open No.
There is "a method for detecting damage to a sun gear" disclosed in Japanese Patent No. 168519. This detection method is a method of detecting damage generated in the sun gear of the planetary type planetary gear mechanism that is operating, by using meshing sound or vibration. That is,
The meshing noise or vibration occurring at any revolution angle of the planetary gear is detected at regular intervals synchronized with the revolution of the planetary gear, and the arithmetic mean of the required number of signals from each of the two types of detected time series signals is detected. 2 obtained from the arithmetic mean
It is a method to detect the damage generated in the sun gear of the planetary gear mechanism in operation from the component ratio of two signals.

[0003]

The conventional diagnosis method detects damages occurring in the sun gear by detecting meshing vibrations occurring at a certain revolution angle of the planetary gear at regular intervals synchronized with the revolution. Therefore, the damage detection range is narrow and the damage range is limited. Therefore, it takes a lot of effort to detect the damage of the device composed of many parts, which is not suitable for the actual application. It was In other words, the planetary gear mechanism generally has many components and is complicated, and the damaged parts are also diverse.Therefore, even if a diagnostic method with a narrow damage detection range such as the conventional example is applied, the kind and the part of the damage can be accurately identified. Cannot be specified. Further, the conventional diagnostic method has a problem that knowledge of vibration of the planetary gear mechanism is required, and therefore only a skilled person can determine the type and site of damage. Further, in addition to the vibration signal detector for detecting meshing vibration, a rotation detector for detecting a signal synchronized with the revolution is required, which causes a problem of increasing the cost of the diagnostic device.

Therefore, according to the present invention, when diagnosing the type, site and degree of damage of the planetary gear mechanism, the range of damage detection is wide and it is possible for non-experts to determine the type, site and degree of damage. It is an object of the present invention to provide a diagnostic method capable of economically configuring a diagnostic device.

[0005]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a vibration detecting section for detecting each specific frequency generated in the vicinity of a planetary gear mechanism based on the rotating operation of each part of the planetary gear mechanism. With the provision of a diagnostic processing unit for automatically diagnosing the type and site of damage to the planetary gear mechanism and the specific frequency based on a diagnostic rule, the detection signals of the specific frequency and the higher frequency detected by the vibration detection unit are provided. Extract and calculate the relative value of the initial value of the specific frequency and the initial value of the higher order frequency when the maintenance condition of the planetary reducer is good, and determine that the relative value exceeds the reference value based on the diagnostic rule. In this case, the diagnostic processing unit identifies the type and site of the corresponding damage from the corresponding specific frequency. Further, it is a diagnostic processing method in which the type of damage and the name of the site are displayed.

[0006]

Therefore, when diagnosing the type and site of damage to the planetary gear mechanism, the type and site of each damage can be accurately diagnosed, and the rotation detector is not required, so that the diagnostic device can be economically constructed. . In addition, since the type and site of damage are displayed, even a non-expert can easily determine the type, site and degree of damage.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a cross section of a planetary speed reducer,
An example of a two-stage planetary speed reduction mechanism is shown.
In the figure, the planetary reduction mechanism of the first stage is the input shaft 11,
The sun gear 12 fixed to the input shaft 11, the plurality of planetary gears 13 meshing with the sun gear 12 and revolving around the sun gear 12, the inner gear 14 fixed to the device and meshing with the planetary gear 13, and the planetary gear 13 revolving. It is composed of a spider 16 that transmits to the output shaft 15.

Similarly, the second stage planetary gear mechanism also has an input shaft 21, a sun gear 22 fixed to the input shaft 21, and a plurality of planet gears 23 that mesh with the sun gear 22 and revolve around the sun gear 22. The internal gear 24 fixed to the device meshes with the planetary gear 23, and the spider 26 that transmits the revolution of the planetary gear 23 to the output shaft 25. Then, the rotation of the output shaft 15 of the first stage is transmitted to the input shaft 21 of the second stage by the coupling mechanism 20. The gears of the first and second planetary gear mechanism units are supported by rolling bearings or sliding bearings (not shown).

Next, FIG. 2 is a diagram schematically showing the principle of this planetary speed reducer. The principle of deceleration operation of this planetary speed reducer will be described with reference to FIG. In FIG. 2, the input shaft 1 of the first stage
When 1 rotates, the sun gear 12 fixedly connected thereto also rotates in the same direction, that is, in the clockwise direction in the figure. Then, the planetary gears 13A to 13C meshing with the sun gear 12 and the internal gear 14 respectively rotate counterclockwise, and since the internal gear 14 is fixed to the device, the planetary gears 13A to 13C move in the directions indicated by the dotted arrows in the figure. Rotate. That is, the planetary gear revolves around the sun gear 12 while rotating on its axis.

The revolution speed of the planetary gear 13 is reduced with respect to the revolution speed of the sun gear 12, and the reduced revolution movement is transmitted to the output shaft 15 via the spider 16. Then, it is transmitted to the input shaft 21 of the planetary gear unit of the second stage via the coupling mechanism unit 20, and is further decelerated in the same manner by the planetary gear unit of the second stage, and the decelerated rotation output is output from the output shaft 25. It has been obtained.

Such a planetary speed reducer has a very complicated structure as compared with other rotary machines. Therefore, if an abnormality occurs, it is necessary to stop the operation of the device and remove each part of the device to investigate the abnormal part,
There is a demand for the development of a diagnostic system capable of diagnosing abnormal points during operation. Therefore, the present invention focuses on the fact that each part of the planetary gear reducer generates an inherent vibration that is mechanically and kinematically determined in correspondence with equipment specifications during operation of the planetary gear reducer.
A vibration detection unit, which will be described later, is arranged in the vicinity of the planetary speed reducer, and each natural frequency spectrum of each part called a specific frequency spectrum is analyzed from the obtained vibration signal to analyze the damage type, part and To be able to diagnose the degree.

Next, each specific frequency generated in each part of the first stage of the planetary speed reducer can be obtained by the following equations (1) to (8), that is, the input shaft 11 of the planetary speed reducer. When the number of rotations is n (rpm), the rotation frequency (specific frequency) fr of the input shaft 11 can be expressed as in Expression (1). fr = n / 60 [Hz] (1) Further, the number of teeth of the sun gear 12 is ZS, the number of teeth of the planetary gear 13 is ZP, the number of teeth of the internal gear 14 is ZR, and the sun gear 12
Let frs be the rotation frequency of the first stage sun gear 12 (the same as the rotation speed of the input shaft 11 in the case of the first stage).
The rotation frequency (specific frequency) frp of 3 can be expressed by equation (2). frp = frs.ZS.ZR / (ZS + ZR) ZP [Hz] (2)

The revolution frequency (specific frequency) fr of the planetary gear 13 can be expressed by the equation (3). fro = frs · ZS / (ZS + ZR) [Hz] (3) Further, the fundamental frequency (specific frequency) fis at which one point of the sun gear 12 contacts one planetary gear 13 can be expressed by the equation (4). . fis = frs (ZS + 2ZP) / 2 (ZS + ZP) [Hz] (4) Further, the basic frequency (specific frequency) fbp at which one point of the planetary gear 13 comes into contact with the sun gear 12 or the internal gear 14 is represented by the formula (5). be able to. fbp = frs.ZS (ZS + 2ZP) / ZP (ZS + ZP) [Hz] (5)

The basic frequency (specific frequency) fo at which one point of the internal gear 14 contacts one planetary gear 13 can be expressed by the equation (6). fo = frs · ZS / (ZS + ZR) [Hz] (6) Further, the meshing frequency (specific frequency) between the sun gear 12 and the planetary gear 13 or the meshing frequency (specific frequency) fgm between the planetary gear 13 and the internal gear 14 is , Can be expressed by equation (7). fgm = ZS · fis [Hz] (7) The rotation frequency fr of the input shaft 21 at the second stage (second stage) is equal to the revolution frequency fro of the planetary gear 13, and therefore can be expressed as in equation (8). Each specific frequency in each of the second and subsequent stages can be obtained by the same calculation using the equations (2) to (8). fr i (2nd stage) = fr [Hz] (8)

According to the present invention, the spectrum of each specific frequency calculated by each of the above arithmetic expressions is detected by the vibration detecting unit as the initial value of the specific frequency as the one corresponding to the time when the maintenance condition of the planetary speed reducer is in good condition. At the same time, the initial value is compared with the detection signal of the specific frequency spectrum detected by the vibration detection unit from the next time onward, and the type and site of each damage of the planetary speed reducer can be specified according to the magnitude.
Next, FIG. 3 is a system diagram of an abnormality diagnosis system to which the diagnosis method of the present invention is applied. In the figure, 51 is an equipment specification input unit, 52 is an analysis condition setting unit, 53 is an analysis condition storage unit,
54 is a vibration detector, 55 is an amplifier, 56 is a signal processor,
57 is an A / D converter. Further, 58 is a digital frequency analysis unit, 59 is a time series data calculation unit, 60 is a time series feature matrix storage unit, 61 is a time series abnormality sign matrix formation unit, 62 is an abnormality sign matrix storage unit, and 64 is an initial value spectrum storage unit. Reference numeral 65 is a control unit, 66 is a diagnostic determination rule setting unit, and 67 is a diagnostic determination rule storage unit.

Here, the equipment specification input section 51 inputs equipment specifications indicated by specifications of rotating elements such as the number of teeth of each gear of the planetary speed reducer to be diagnosed and specifications of bearings. The analysis condition setting unit 52 automatically performs signal analysis such as types and detection positions of detection signals such as vibration and rotation speed, types of signal processing, analysis frequency band, frequencies corresponding to various abnormalities of the planetary speed reducer. The data defining the conditions and the method for performing is set, and these data are stored in the analysis condition storage unit 53.

Further, the vibration detector 54 detects the vibration generated from each part of the planetary speed reducer as described above. Then, the signal is processed by the signal processing unit 56 after being amplified by the amplifier 55.
Signal processing such as filtering is performed by the digital frequency analysis unit 5 by the A / D converter 57.
Give to eight. The digital frequency analysis unit 58 performs frequency analysis, and supplies the obtained frequency spectrum and the higher-order frequency spectrum to the time-series data calculation unit 59. On the other hand, in the initial value spectrum storage unit 64, the frequency spectra of the specific frequency and the higher order frequency when the planetary speed reducer is in a good maintenance state are stored in advance as the initial value of the baseline data, and this data is stored in time series. It is given to the data calculation unit 59. The time-series data calculation unit 59 calculates a time-series feature amount corresponding to various abnormalities of the planetary speed reducer, and stores this in the time-series feature matrix storage unit 60.

Table 1 shows an example of the structure of such a time-series matrix, and shows each time-series data corresponding to the above-mentioned specific frequency and higher order frequency. In Table 1, S ₀ (i)
Is an initial value spectrum, and R (i, 1) and R (i, 2) are time-sequential relative spectral ratios described later.

[0019]

[Table 1]

By the way, the time series abnormality sign forming section 61 is
Using the below-mentioned reference value group stored in the analysis condition storage unit 53, only the data in which the abnormality sign has progressed to a certain level or more is extracted, and the extracted data includes the type of abnormality, the site, and the specific frequency spectrum corresponding to the abnormality. To form an abnormal symptom matrix. Then, the formed abnormal sign matrix is stored in the abnormal sign matrix storage unit 62. The diagnosis determination unit 63, for the abnormality sign matrix,
By applying the diagnosis determination rule set by the diagnosis determination rule setting unit 66 and stored in the diagnosis determination rule storage unit 67, the type of the abnormality, the site, the degree of the abnormality, the remaining life, etc. are determined and displayed. The control unit 65 has a function of automatically executing and controlling the series of diagnostic processes described above.

Next, a basic diagnosis method of the diagnosis system having the above structure will be described with reference to the above table. The time series data calculation unit 59 includes the initial value spectrum S ₀ (i) shown in FIG. 4A and the time series spectrum S (i, j) shown in FIG. 4B obtained by the digital frequency analysis unit 58. From the time series relative spectral ratio R (i, j) = S (i, j) / S
A time-series feature amount such as a time-series relative value of a spectrum component corresponding to an abnormality of ₀ (i) or an index expressing the feature of the spectrum is calculated to form a time-series feature matrix. On the other hand, in the analysis condition storage unit 53, the reference frequency L (i) for determining the specific frequency of vibration corresponding to the abnormality of the planetary speed reducer or the degree of progress of the abnormality is calculated for each speed reducer and for each vibration measurement point.
It is set for each vibration signal processing condition and each type of abnormality.

The time series abnormality sign matrix forming section 61 is
Here, it is determined whether or not the abnormal sign has progressed based on the relationship of R (i, j)> L (i), and the abnormal type and region are determined for the data in which the abnormal sign has progressed above a certain level. And the specific frequency spectrum corresponding to the anomaly are added to form the anomaly symptom matrix as shown in Tables 2 and 3.

[0023]

[Table 2]

[0024]

[Table 3]

Here, in each of the above tables, k is a series of numbers assigned to data sections, and the data sections are indices indicating a specific frequency spectrum in which an abnormality has progressed above a certain level, or increased above a certain level. It is an index showing the progress of the abnormalities caused. Further, the diagnostic attribute is an index indicating the relationship with the mechanical element or vibration measurement point corresponding to the data section, and the diagnostic variable L is an index indicating the type of diagnostic information required when making a diagnostic determination of abnormality. In addition, the applied diagnostic rule represents all types of abnormalities related to the data division, and the time-series relative spectral ratio R (R) is relative to the initial value of the time-series relative spectral ratio related to the data division or the index indicating the progress of the abnormality. It is a relative ratio.

When the abnormality symptom matrix is formed as described above, the diagnosis judgment unit 63 uses R (R) as the diagnosis variable L in the diagnosis judgment rule when making a diagnosis judgment of the kind and site of the abnormality. The following values are set for all variables V to be set. However, V (N) = S (N = L) V (N) = M (N = L) V (N) = W (N ≠ L) where S>M> W in the above equations Shall have. That is, S has a large degree of abnormal development related to the diagnostic data, M has a medium degree of abnormal development, W
Indicates that the degree of abnormal development is small.

With this configuration, the diagnostic rules for diagnosing the type of abnormality are shown in Table 2 and Table 3 as follows: IF (A01): [(V (1) ≧ M) AND (V (2) ≧ M) AND (V (3) ≧ M) AND (V (4) ≧ M) AND (V (5) ≧ M) AND (V (6) ≧ M)], the error type A01 ELSE (A02): [( V (1) ≧ M) AND (V (2) ≧ M) AND (V (24) ≧ M) AND (V (25) ≧ M)], the error type A02 ELSE (A03): [(V ( 2) ≧ M) AND (V (4) ≧ M) AND (V (6) ≧ M)], the error type A03

When ELSE (A04): [(V (2) ≥M) AND (V (4) ≥M)], when abnormality type A04 ELSE (A05): [(V (4) ≥M)] , Abnormality type A05 ELSE (A06): [(V (2) ≥M)], abnormality type A06 ELSE (B01): [(V (20) ≥M) OR (V (21) ≥M) OR ( V (23) ≧ M)], it can be expressed as an abnormality type B01, and therefore, a simple structure can be obtained, so that a diagnosis determination can be made by a simple process.

The following Tables 4 to 7 show the following when damage to the planetary gear mechanism is diagnosed by the above abnormality diagnosis system:
It shows a representative damage name of the planetary gear mechanism that can be diagnosed, each damaged portion, and its damage name.

[0030]

[Table 4]

[0031]

[Table 5]

That is, for example, in the case where one tooth surface of the planetary gear is damaged, when the planetary gear having this damaged portion meshes with either the sun gear or the internal gear, the vibration frequency shown in equation (9) is generated. . Therefore, in this case, Category 1 in Table 6
The site shown in 3 can be specified as the damaged site. f = fbp / 2 [Hz] (9)

Further, when the teeth on both sides of the planetary gear are chipped and damaged, the planetary gear having the damaged portion is vibrated as shown in equation (10) when the sun gear and the internal gear mesh with each other. Generate frequency. Therefore, in this case, it can be specified as a local abnormality of the planetary gears shown in the section 5 of Table 4 or the section 18 of Table 6. f = fbp [Hz] (10) Hereinafter, the type, site and degree of damage shown in Tables 4 to 7 can be determined by the same method.

[0034]

As described above, according to the present invention, a vibration detecting unit for detecting each specific frequency generated based on the rotation operation of each part of the planetary gear mechanism is provided in the vicinity of the planetary gear mechanism, and the planetary gear mechanism is provided. A diagnostic processing unit that automatically diagnoses by associating the type and site of damage of the mechanism with a specific frequency based on a diagnostic rule is provided, and the detection signals of the specific frequency and higher order frequency detected by the vibration detection unit are extracted and detected. The relative value of the initial value of the specific frequency and the initial value of the higher order frequency are calculated, and when the relative value is determined by the diagnostic rule to exceed the reference value, the diagnostic processing unit handles it from the corresponding specific frequency. Since the type, part and degree of damage to be specified are specified, the type, part and degree of damage can be accurately diagnosed even during operation of the planetary gear mechanism, and rotation is performed during diagnosis. There is an effect that output device can be economically configure diagnostic device because it is unnecessary. Further, since the names of the types, parts and degrees of the damaged parts are displayed, it is possible for a person other than an expert to easily determine the kind, part and degree of the damage.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a cross section of a planetary speed reducer.

FIG. 2 is a diagram schematically showing an operation of the planetary speed reducer.

FIG. 3 is a block diagram showing the configuration of a diagnostic system to which the diagnostic method for planetary gears according to the present invention is applied.

FIG. 4 is a diagram showing a relationship between spectral component values and frequencies.

[Explanation of symbols]

11, 21 ... Input shaft, 12, 22 ... Sun gear, 13, 2
3 ... Planetary gears, 14, 24 ... Internal gears, 15, 25 ... Output shaft, 16, 26 ... Spider, 20 ... Coupling mechanism, 51 ... Equipment specification input section, 52 ... Analysis condition setting section, 5
4 ... Vibration detection unit, 56 ... Signal processing unit, 58 ... Digital frequency analysis unit, 59 ... Time-series data calculation unit, 61 ... Time-series abnormality sign feature matrix formation unit, 63 ... Diagnosis determination unit, 6
4 ... Initial value spectrum storage unit, 66 ... Diagnostic judgment rule setting unit.

Claims (2)

[Claims] 1. A sun gear that rotates in association with the rotation of an input shaft, an internal gear that is fixedly arranged, and a sun gear that meshes with the sun gear and the internal gear to rotate and revolves around the sun gear. In a diagnostic method for diagnosing the type, part and degree of damage of a planetary gear mechanism including a planetary gear that transmits rotation to an input shaft of a next stage through an output shaft, a planetary gear mechanism near the planetary gear mechanism is provided. A diagnostic processing unit that includes a vibration detection unit that detects each specific frequency generated based on the rotation operation of each unit, and that automatically diagnoses by associating the specific frequency with the type and site of damage of the planetary gear mechanism based on a diagnostic rule. The detection signal of the specific frequency and the higher order frequency detected by the vibration detection unit is extracted, and the initial value of the specific frequency when the maintenance condition of the planetary speed reducer is good, and the higher order frequency While calculating each relative value of the initial value, when the relative value is judged to exceed the reference value based on the diagnosis rule, the type, site and degree of damage corresponding to the specific frequency in the diagnosis processing unit. A method for diagnosing a planetary gear, which comprises: 2. The method for diagnosing a planetary gear according to claim 1, wherein the name of the type, site and degree of the damage is displayed.