Vibration analysis device and abnormal portion identification system including same

Abstract

A vibration analysis device disclosed herein comprises a control device (31) and a display device (34). The control device (31) determines candidate portions corresponding to each of the peaks of a frequency spectrum on the basis of a feature frequency generated due to an abnormality in a portion of a rotating body. The control device (31) excludes a specific portion from the candidate portions and determines the remaining candidate portions as abnormal portions when a second peak of a lower corresponding order than a first peak corresponding to the feature frequency of the specific portion is not present in the frequency spectrum. The control device (31) causes the display device (34) to display an abnormal portion for each peak of the frequency spectrum.

Description

Vibration analysis device and abnormal part identification system equipped with the same

[0001] The present disclosure relates to a vibration analysis device and an abnormal part identification system including the same, and more particularly to a technique for improving the accuracy of identifying an abnormal part in a rotating body.

[0002] As rotating parts are used, their bearings and other components may suffer from damage, wear, and other abnormalities. Therefore, abnormality diagnosis of rotating parts is performed periodically. A method for diagnosing abnormalities in rotating parts is known, which involves analyzing the vibration of the rotating parts. For example, a method is known in which signals acquired from an acceleration sensor installed in the bearing are subjected to FFT (fast Fourier transform) processing to extract signals of vibration-generating frequency components and identify abnormal parts in the rotating parts. Vibration analyzers used for such vibration measurement generally perform frequency analysis of signals from the acceleration sensor, and display the analysis results as a graph of acceleration for each frequency, which can be shown to the user.

[0003] Japanese Patent No. 7360887 (Patent Document 1) discloses a vibration analysis device that performs vibration analysis and indicates areas that may be damaged. Japanese Patent Laid-Open Publication No. 2006-234786 (Patent Document 2) discloses an abnormality diagnosis device for mechanical equipment. These devices measure the vibration of a bearing, which is the object of measurement, and indicate possible areas where an abnormality exists based on the frequency components of a frequency spectrum obtained by frequency analysis and the characteristic frequency of the bearing.

[0004] Japanese Patent No. 7360887 Japanese Patent Laid-Open No. 2006-234786

[0005] The devices described in Patent Documents 1 and 2 present candidates for areas where an abnormality exists based on the peaks of the frequency spectrum. Therefore, a user can recognize the candidates for areas where an abnormality exists based on the presented content, regardless of the user's level of proficiency. However, Patent Documents 1 and 2 do not consider the validity of the candidates for areas where an abnormality exists identified by the device. Therefore, the user must identify the area where an abnormality exists from the presented candidates, and depending on the user's level of proficiency, it may be difficult to identify the area where an abnormality exists.

[0006] An object of the present disclosure is to improve the accuracy of identifying abnormal parts in a vibration analysis device that receives measurement data from a measuring instrument that measures the vibration of a rotating body that is the measurement target, and presents abnormal parts that are parts of the rotating body that may be abnormal.

[0007] A vibration analysis device according to one aspect of the present disclosure receives measurement data from a measuring instrument that measures vibrations of a rotating body and identifies anomalous parts of the rotating body that may be abnormal, and includes a control device and a display device. The control device receives information about the rotating body and performs frequency analysis of the measurement data. Based on the information, the control device calculates feature frequencies caused by abnormalities in each part of the rotating body and determines candidate parts corresponding to each peak in a frequency spectrum obtained by the frequency analysis based on the feature frequencies. If a first peak corresponding to the feature frequency of the specific part is present in the frequency spectrum and a second peak corresponding to the feature frequency of the specific part and having a lower order than the first peak is not present in the frequency spectrum, the control device excludes the specific part from the candidate parts and determines the remaining candidate parts as anomalous parts. The control device displays the determined anomalous parts for each peak in the frequency spectrum on the display device.

[0008] A vibration analysis device according to another aspect of the present disclosure receives measurement data from a measuring instrument that measures vibrations of a rotating body and identifies anomalous parts that are candidates for parts of the rotating body that may be abnormal. The vibration analysis device includes a control device and a display device. The control device receives information about the rotating body and tolerance bands for each of characteristic frequencies caused by an abnormality in each part of the rotating body, calculated based on the information. The control device performs frequency analysis of the measurement data to calculate each of the characteristic frequencies and determines the anomalous part based on whether the frequency of each peak in a frequency spectrum obtained by the frequency analysis is within the tolerance band. When one or more parts are determined to be anomalous parts for a fourth peak included in the frequency spectrum, the control device calculates a difference between each of the characteristic frequencies of the one or more parts and the frequency of the fourth peak. The control device causes the display device to display the one or more parts as anomalous parts in a manner based on the difference for the fourth peak.

[0009] According to the vibration analysis device according to the present disclosure, it is possible to improve the accuracy of identifying an abnormal portion of a rotating body that is the measurement target.

[0010] FIG. 1 is a diagram showing the configuration of an abnormal portion identification system. FIG. 2 is a diagram showing the configuration of a measuring instrument. FIG. 3 is a diagram showing the configuration of a portable information terminal. FIG. 4 is a diagram for explaining the contents of a first process. FIG. 5 is a diagram for explaining the contents of a second process. FIG. 6 is a diagram showing an example of display by a display device. FIG. 7 is a diagram for explaining the contents of a third process. FIG. 8 is a diagram showing another example of display by a display device. FIG. 9 is a diagram showing an example of setting information input by an input device. FIG. 10 is a flowchart showing an example of a processing procedure in a measuring instrument. FIG. 11 is a flowchart showing an example of a processing procedure in a portable information terminal.

[0011] Hereinafter, the present embodiment will be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals and description thereof will not be repeated.

[0012] [Configuration of Abnormal Part Identifying System] Fig. 1 is a diagram showing an abnormal part identifying system according to the present embodiment. Referring to Fig. 1, abnormal part identifying system 10 includes measuring instrument 20 and portable information terminal 30.

[0013] Measuring instrument 20 is a device for measuring vibrations occurring in rolling bearing 15, which is the measurement target, and is configured to include an acceleration sensor (not shown) for detecting vibrations. Measuring instrument 20 is configured to be able to communicate wirelessly with portable information terminal 30, and upon receiving a measurement start signal from portable information terminal 30, measures vibrations occurring in rolling bearing 15 using the acceleration sensor. Measuring instrument 20 then transmits acceleration data detected by the acceleration sensor to portable information terminal 30. Note that measuring instrument 20 may also be connected to portable information terminal 30 by wire so as to be able to communicate with it.

[0014] The portable information terminal 30 is the "vibration analysis device" in the present disclosure, and receives measurement data (vibration acceleration data) from the measuring instrument 20 and analyzes the vibration occurring in the rolling bearing 15. The portable information terminal 30 is a terminal that can be used by a user of the abnormal part identification system 10, and is, for example, a smartphone or a tablet. Application software running on the portable information terminal 30 allows the portable information terminal 30 to be used as the "vibration analysis device."

[0015] Fig. 2 is a diagram showing the configuration of measuring device 20. Referring to Fig. 2, measuring device 20 includes an acceleration sensor 102, an anti-aliasing filter 104, an A / D converter 106, a microcomputer 108, a memory 110, and a communication module 112.

[0016] Acceleration sensor 102 is attached to rolling bearing 15 (FIG. 1) that is the measurement target, and detects and outputs the acceleration of vibrations occurring in rolling bearing 15. Anti-aliasing filter 104 is a low-pass filter for suppressing aliasing errors that occur during A / D conversion in A / D converter 106. A / D converter 106 converts the measurement signal (analog signal) that has passed through anti-aliasing filter 104 into a digital signal.

[0017] Microcomputer 108 receives the acceleration data converted into a digital signal by A / D converter 106 and outputs it to memory 110. Then, when a predetermined amount of data has been accumulated in memory 110, microcomputer 108 reads the accumulated data from memory 110 and transmits it to mobile information terminal 30 via communication module 112 as measurement data from measuring instrument 20.

[0018] Memory 110 receives from microcomputer 108 the acceleration data converted into a digital signal by A / D converter 106 and temporarily stores the data. Communication module 112 is a wireless module that enables measuring instrument 20 to communicate with portable information terminal 30.

[0019] 3 is a diagram showing the configuration of the portable information terminal 30. The portable information terminal 30 includes a control device 31, a display device 34, an input device 35, and a communication device 36.

[0020] The control device 31 includes a processor 32 and a memory 33. The processor 32 is, for example, a CPU (Central Processing Unit) and is a processing circuitry that executes predetermined arithmetic processing described in a program. The processor 32 reads out the program and data stored in the memory 33, and identifies a portion of the rolling bearing 15 that is the object of measurement by the measuring instrument 20 that is likely to have an abnormality.

[0021] The memory 33 includes non-volatile or volatile memory such as a read-only memory (ROM) or a random access memory (RAM), and / or a large-capacity storage device such as a hard disk drive (HDD) or a solid state drive (SSD). The memory 33 stores, for example, programs for executing the various processes performed by the processor 32, information received from the input device 35, and acceleration data generated by the measuring instrument 20.

[0022] A display device 34, an input device 35, and a communication device 36 are connected to the control device 31. The display device 34 is, for example, a liquid crystal display (LCD) or an organic electroluminescence (EL) display. The control device 31 causes the display device 34 to display the measurement results of the measuring device 20 and the candidate and / or abnormal areas identified by the processor 32.

[0023] The input device 35 is, for example, a keyboard, a mouse, a pointing device, a touch panel, or the like, and receives user operations.

[0024] Communication device 36 is a device that enables portable information terminal 30 to communicate wirelessly with measuring device 20. In accordance with instructions from control device 31, communication device 36 transmits a measurement start signal to measuring device 20 when vibration measurement by abnormal part identification system 10 begins. Communication device 36 also receives measurement data transmitted from measuring device 20.

[0025] The control device 31 receives information relating to the rolling bearing 15 to be measured via the input device 35. In this embodiment, the information to be set is input by the user from the screen of the mobile information terminal 30, but it may also be stored in advance in the memory 33 and read out by the control device 31 from the memory 33 when vibration measurement by the abnormal part identification system 10 begins. The information relating to the rolling bearing 15 is, for example, the bearing model number of the rolling bearing 15, and the rotational speed or rotational frequency of the rolling bearing 15 during measurement by the measuring instrument 20.

[0026] In this embodiment, specification data for various bearings whose vibrations can be measured by the abnormal part identification system 10 is associated with the bearing model number and stored in advance in the memory 33. The control device 31 then reads out the specification data for the bearing from the memory 33 using the bearing model number received from the input device 35 as an index. Note that the specification data for the rolling bearing 15 may also be input from the input device 35 as information about the rolling bearing 15.

[0027] The control device 31 also receives a judgment reference value for judging the vibration state of the rolling bearing 15 that is the measurement target. In this embodiment, this judgment reference value is also input by the user from the screen of the mobile information terminal 30, but it may also be stored in advance in the memory 33 and read from the memory 33 when the abnormal part identification system 10 starts vibration measurement.

[0028] The control device 31 performs frequency analysis on the measurement data received from the communication device 36. As an example, the control device 31 performs FFT processing on the time-series acceleration data received from the communication device 36 to generate a frequency spectrum of the measurement data.

[0029] The memory 33 stores specification data of various bearings whose vibrations can be measured by the abnormality part identification system 10, in association with the bearing model number. In this embodiment, the specification data includes data from which frequencies observed when an abnormality occurs in each part of the rotating body can be calculated. Specifically, the specification data includes at least data from which the inner ring pass frequency (BPFI), outer ring pass frequency (BPFO), and rolling element rotation frequency (BSF) shown in the following equations (1) to (3) can be calculated.

[0030]

[0031] Here, D is the pitch diameter of the bearing, d is the diameter of the rolling elements, α is the contact angle of the rolling elements, and Z is the number of rolling elements. Note that f0 is the rotational frequency of the shaft, which is received by the control device 31 via the input device 35, or, if the rotational speed is set by the control device 31, is calculated from that rotational speed.

[0032] The memory 33 stores at least the specification data of the pitch circle diameter D, the diameter d of the rolling elements, the contact angle α of the rolling elements, and the number Z of the rolling elements, in association with the bearing model number. Note that instead of these specification data, coefficients Cin, Cout, and Crol of the rotational frequency f0 for calculating BPFI, BPFO, and BSF, respectively, may be stored in the memory 33. The coefficients Cin, Cout, and Crol are expressed by the following equations (4) to (6).

[0033]

[0034] The control device 31 calculates the BPFI, BPFO, and BSF of the rolling bearing 15 at the time of measurement based on the received information about the rolling bearing 15. Specifically, the control device 31 reads from the memory 33 the specification data of the bearing corresponding to the bearing model number received via the input device 35, and calculates the BPFI, BPFO, and BSF from the read specification data and the set rotational speed (or rotational frequency) using the above formulas (1) to (3).

[0035] The control device 31 identifies candidate portions, which are portions where there is a possibility that an abnormality may exist, for each peak in the frequency spectrum of the measurement data received from the measuring device 20. In this process, the tolerance range included in the information received from the input device 35 is used. Specifically, for a peak whose frequency (hereinafter referred to as the "peak frequency") in the frequency spectrum falls within a tolerance range set based on the tolerance ranges of BPFI and its higher-order components, the inner ring is assumed to have a defect, and the inner ring is identified as the candidate portion. Furthermore, for a peak whose peak frequency falls within the tolerance ranges of BPFO and its higher-order components, the outer ring is identified as the candidate portion, and for a peak whose peak frequency falls within the tolerance ranges of BSF and its higher-order components, the rolling element is identified as the candidate portion.

[0036] Furthermore, if the peak frequency is included in the allowable range of the shaft rotation frequency and its higher-order components, it is estimated that shaft imbalance has occurred. If the peak frequency is included in the allowable range of the frequency twice the rotation frequency and its higher-order components, it is estimated that misalignment has occurred. Therefore, if the peak frequency is included in the allowable range of the shaft rotation frequency and its higher-order components, the processor 32 determines that there is a malfunction in the rotating shaft and identifies the rotating shaft as a candidate part. As such, in this embodiment, for the candidate parts corresponding to the peak, not only the bearing parts (inner ring, outer ring, rolling elements) corresponding to BPFI, BPFO, and BSF but also rotating shaft malfunctions caused by shaft imbalance and misalignment are identified.

[0037] In this specification, frequencies caused by damage to the inner ring, outer ring, and rolling elements, and frequencies caused by shaft imbalance and misalignment are referred to as characteristic frequencies. Candidate parts are identified based on the presence or absence of a peak whose frequency falls within an allowable range that is set based on the characteristic frequency and the allowable width.

[0038] The control device 31 judges the vibration state for each peak based on the peak value, which is the acceleration of the peak in the frequency spectrum, and the judgment reference value. For example, the control device 31 judges a peak whose peak value exceeds the judgment reference value as "danger." Furthermore, the control device 31 judges a peak whose peak value is lower than the judgment reference value but exceeds 80% of the judgment reference value as "caution," and judges a peak whose peak value is lower than 80% of the judgment reference value as "good."

[0039] [Comparative Example] When rotating parts are used, their bearings and other parts may suffer from abnormalities such as damage and wear. For this reason, abnormality diagnosis is performed on rotating parts periodically. A method for diagnosing abnormalities in rotating parts is known as a method for analyzing the vibration of rotating parts. A vibration analysis device used for vibration measurement generally performs frequency analysis on signals from an acceleration sensor, and displays the analysis results in the form of a graph of acceleration for each frequency, which is shown to the user.

[0040] Conventional vibration analysis devices, such as those disclosed in Patent Documents 1 and 2, measure the vibration of a bearing to be measured, extract a predetermined number of peaks from the largest peak values ​​in a frequency spectrum obtained by frequency analysis, and present candidate damaged areas based on the characteristic frequencies of the bearing. However, if the specifications of the bearing to be measured differ from those expected, or if the rotational speed fluctuates and the frequency changes, an area that does not actually have an abnormality may be selected as the abnormal area. While an experienced user can refer to the display of the vibration analysis device and determine the validity of the displayed content, it may be difficult for an inexperienced user to determine the validity of the displayed content. Therefore, it is desirable to improve the accuracy of identifying abnormal areas in a vibration analysis device.

[0041] [Vibration Analysis Device According to the Embodiment] Therefore, the portable information terminal 30, which is the vibration analysis device according to the present embodiment, identifies candidate abnormal parts by comparing the frequencies of the peaks in the frequency spectrum obtained by frequency analysis with the characteristic frequencies derived from each part, and then excludes from the candidate abnormal parts those parts that are unlikely to be abnormal parts and identifies the remaining candidate abnormal parts as abnormal parts. The portable information terminal 30 then presents the abnormal parts from which the parts unlikely to be abnormal have been excluded to the user. The display on the portable information terminal 30 allows the user, regardless of the user's level of proficiency, to recognize parts that are likely to be abnormal.

[0042] Furthermore, when the portable information terminal 30, which is the vibration analysis device according to this embodiment, identifies that one peak in the frequency spectrum is a peak caused by abnormalities in two or more different parts, it determines priorities for the two or more parts.The portable information terminal 30 then presents the two or more parts to the user so that the user can recognize the priorities.When it is identified that one peak in the frequency spectrum is caused by abnormalities in two or more parts, the display on the portable information terminal 30 allows the user to recognize which part is more likely to have an abnormality.

[0043] The following describes three processes performed by the mobile information terminal 30 according to the present disclosure and the content displayed on the display device 34 after the three processes.

[0044] <First Process> The control device 31 identifies a candidate region for each peak based on the peak frequency and feature frequency of each peak in the frequency spectrum of the measurement data received from the measuring device 20. The control device 31 selects an abnormal region from the identified candidate regions that is highly likely to be an abnormal region. Specifically, when a peak frequency is identified as a high-order component of the feature frequency of a specific region, the control device 31 determines whether the peaks in the frequency spectrum include a peak identified as a low-order component of the feature frequency of the specific region. When the peaks in the frequency spectrum do not include a peak corresponding to a low-order component of the feature frequency of the specific region, the control device 31 excludes the specific region from the candidate regions and does not select it as an abnormal region.

[0045] Fig. 4 is a diagram for explaining the first process executed in the control device 31. Fig. 4 shows an example of a frequency spectrum generated by performing FFT processing on the time-series acceleration data measured by the measuring device 20.

[0046] In FIG. 4 , assume that the frequency of peak P1 is included in the allowable range of the outer ring second-order component. In this case, the processor 32 checks whether there is a peak in the frequency spectrum that is included in the allowable range of the outer ring first-order component, which is lower than the outer ring second-order component. If the control device 31 confirms that peak P2 is detected within the allowable range of the outer ring first-order component, it determines that peak P1 corresponds to the outer ring second-order component. On the other hand, if peak P2 is not confirmed within the allowable range of the outer ring first-order component, the control device 31 determines that peak P1 does not correspond to the outer ring second-order component. Therefore, if peak P2 is not confirmed within the allowable range of the outer ring first-order component, even if peak P1 is confirmed within the allowable range of the outer ring second-order component, the "outer ring" is excluded from the candidate parts and is not selected as an abnormal part.

[0047] <Second Process> When the control device 31 determines that the frequency spectrum includes the peak of the high-order component of a predetermined part and the peak of the low-order component of the predetermined part, the control device 31 determines whether the peak value of the high-order component is equal to or less than the peak value of the low-order component. If the peak value of the high-order component is not equal to or less than the peak value of the low-order component, the control device 31 excludes the predetermined part from the candidate parts.

[0048] Fig. 5 is a diagram for explaining the second process executed by the control device 31. Fig. 5 shows an example of a frequency spectrum generated by the control device 31 performing FFT processing on the time-series acceleration data measured by the measuring device 20.

[0049] In Figure 5, the frequency of peak P3 is included in the allowable range of the outer ring secondary component, and the frequency of peak P4 is included in the allowable range of the outer ring primary component. At this time, the control device 31 compares α, which is the peak value of peak P3, with β, which is the peak value of peak P4. In Figure 5, β, which is the peak value of the lower-order peak P4, is smaller than α, which is the peak value of the higher-order peak P3. Therefore, even if peak P4 is confirmed within the allowable range of the outer ring primary component and peak P3 is confirmed within the allowable range of the outer ring secondary component, the "outer ring" is excluded from the candidate parts and is not selected as an abnormal part.

[0050] Fig. 6 is a diagram showing an example of a display screen that the control device 31 causes the display device 34 to display. Fig. 6 shows the screen of the display device 34 on which display information is displayed.

[0051] Referring to FIG. 6, in this example, for peaks having the top 10 peak values, the peak values ​​(acceleration), peak frequencies, judgment results, and abnormal parts are displayed in descending order of peak value (a1>a2>...>a10).

[0052] In Figure 6, the frequency of the fifth-largest peak is included in the inner ring's second-order tolerance range. However, none of the four peaks with higher peak values ​​than this peak is included in the inner ring's first-order tolerance range. Therefore, the inner ring is excluded from the candidate parts by the second process. As a result, when the control device 31 presents abnormal parts to the user, the "inner ring" is not displayed as an abnormal part.

[0053] The first process and the second process are performed based on the fact that, when an abnormality occurs in a predetermined portion of the rotating body, the first-order component of the characteristic frequency of the portion has the largest acceleration, and that the peak acceleration decreases as the order of the characteristic frequency increases. Note that whether or not to perform the first process and the second process may be determined based on a user instruction.

[0054] By executing the first process and the second process, the abnormal part identification system 10 can present to the user the parts that are highly likely to have an abnormality. This allows the user to easily identify the parts of the measurement object that are highly likely to be damaged, without the need to search for peaks of different orders from the detected peak in the display results or to read values ​​from a frequency spectrum graph.

[0055] When misalignment occurs, a frequency twice the rotation frequency and / or its higher-order components are detected as a peak frequency. Therefore, when misalignment occurs, the frequency spectrum may contain a peak at twice the rotation frequency, but no peak at a frequency corresponding to the rotation frequency. In such a case, when the first process and / or the second process are performed, the "rotating axis" corresponding to the misalignment may not be identified as an abnormal part. Therefore, when the rotating axis is identified as a candidate part, the first process and the second process may not be applied. Note that when it is determined that no misalignment occurs, the peaks of the shaft rotation frequency and its higher-order components that fall within the respective allowable ranges may also be applied to the first process and the second process in order to improve the accuracy of unbalance determination.

[0056] <Third Process> When a predetermined peak in the frequency spectrum is identified as being caused by abnormalities in multiple parts, the control device 31 calculates the difference between the peak frequency of the predetermined peak and the characteristic frequency of each of the multiple parts, and determines the priority of the multiple parts based on the difference.

[0057] Fig. 7 is a diagram for explaining the third process executed by the control device 31. Fig. 7 shows an example of a frequency spectrum generated by performing FFT processing on the time-series acceleration data measured by the measuring device 20.

[0058] 7, peak P5 is included in both the allowable range of the inner ring primary and the allowable range of the outer ring secondary. Here, the control device 31 calculates the difference X between the frequency c of peak P5 and the characteristic frequency a of the inner ring primary, and the difference Y between the frequency c of peak P5 and the characteristic frequency b of the outer ring secondary. Because difference Y is smaller than difference X, the control device 31 determines that the outer ring secondary has a higher priority than the inner ring primary as the abnormal part of peak P5.

[0059] 8 is a diagram showing an example of a display screen displayed on the display device 34. In FIG. 8, the screen of the display device 34 is shown.

[0060] 8, the frequency of the peak with the fifth largest peak value is included in the allowable range of the inner ring primary and the allowable range of the outer ring secondary. The control device 31 calculates the difference X between the peak frequency of the fifth largest peak value and the characteristic frequency of the inner ring primary, and the difference Y between the peak frequency of the fifth largest peak value and the characteristic frequency of the outer ring secondary. If the difference Y is smaller than the difference X, the control device 31 determines that the outer ring secondary has a higher priority than the inner ring primary as the abnormal part of peak P5. In the above case, the control device 31 displays the "outer ring secondary" with the higher priority above the "inner ring primary" on the display device 34 as a candidate part for the peak with the fifth largest peak value.

[0061] By executing process 3, when there are multiple abnormal parts corresponding to one peak, the vibration analysis results are displayed based on priority, allowing the user to easily determine which part is most likely to be damaged.

[0062] In FIG. 8, abnormal areas are displayed in descending order of priority, but the present invention is not limited to such a display format. For example, the control device 31 may change the size of the characters in descending order of priority, or change the color of the area according to the priority.

[0063] [Information to be set] Fig. 9 is a diagram showing an example of information received by the control device 31 via the input device 35. The information received by the control device 31 can be input by the user via the input device 35, and Fig. 9 shows a screen displayed on the display device 34 for the user to input the information.

[0064] 9, the user can input the bearing model number of the rolling bearing 15 (FIG. 1) to be measured from input unit 410. In FIG. 9, input unit 410 shows that "6206LLB" has been input as the bearing model number.

[0065] The user can input the rotation speed (rpm) of the shaft during measurement through the input unit 420. Note that this abnormality area identification system 10 is not provided with a sensor for detecting the rotation speed of the shaft during measurement by the measuring instrument 20, so it is necessary to obtain rotation speed information during measurement and input it through the input unit 420. However, if a rotation speed sensor is provided, the input unit 420 is not necessary. Furthermore, the user may input the rotation frequency of the shaft during measurement into the input unit 420 instead of the rotation speed of the shaft during measurement.

[0066] The user can input a judgment reference value (acceleration) through the input unit 430. In this embodiment, the judgment reference value is a uniform value regardless of the peak frequency.

[0067] The user can input the allowable range of the feature frequency through input unit 440 and input unit 445. The user can input the lower limit of the allowable range into input unit 440 and the upper limit of the allowable range into input unit 445. For example, as shown in Fig. 9, when "10" is input into input unit 440 and "5" is input into input unit 445, and the feature frequency of a predetermined part is "300," processor 32 sets 270 to 315 as the allowable range for the predetermined part, and determines that a peak included in this allowable range is a peak corresponding to the predetermined part.

[0068] The input unit 450 allows the user to input the number of top peak values ​​to be displayed on the display device 34. The number of peaks to be displayed is set according to this input value. If there is no input from the input unit 440, a default value (for example, 10) is set.

[0069] The user can input whether or not the first process is to be executed from the input unit 460. When "ON" is selected in the input unit 460, the first process is executed, and when "OFF" is selected, the first process is not executed.

[0070] The user can input whether or not the second process is to be executed from the input unit 470. When "ON" is selected in the input unit 470, the second process is executed, and when "OFF" is selected, the second process is not executed.

[0071] The user can input whether or not the third process is to be executed from the input unit 480. When "ON" is selected in the input unit 480, the third process is executed, and when "OFF" is selected, the third process is not executed.

[0072] The user can set whether to execute the second process independently of the execution of the first process. If the second process is executed without executing the first process, for example, if the frequency spectrum contains a peak corresponding to the outer ring second order but not a peak corresponding to the outer ring first order, the control device 31 cannot acquire the peak value of the peak corresponding to the lower order of the outer ring second order, and therefore cannot execute the second process, and the outer ring second order is not excluded from the candidate parts.

[0073] [Processing Flow in Meter] Figure 10 is a flowchart showing an example of the processing procedure in meter 20. Referring to Figure 2 together with Figure 10, when meter 20 is powered on, microcomputer 108 executes a predetermined initialization process (step S10). The initialization process includes, for example, establishing communication between communication module 112 and portable information terminal 30, clearing data from memory 110, etc.

[0074] Next, microcomputer 108 determines whether or not a measurement start signal has been received from portable information terminal 30 (step S12). If the measurement start signal has been received (YES in step S12), microcomputer 108 reads from A / D converter 106 the output of acceleration sensor 102 that has passed through anti-aliasing filter 104 and been digitally converted by A / D converter 106 (step S14).

[0075] The microcomputer 108 transmits the acquired data to the portable information terminal 30 via the communication module 112 (step S16).

[0076] Next, microcomputer 108 determines whether or not the user has performed a termination operation to terminate the measurement (step S18). The termination operation is performed on portable information terminal 30, and for example, when a measurement termination signal is received from portable information terminal 30, it is determined that the termination operation has been performed.

[0077] If it is determined that the termination operation has not been performed (NO in step S18), the process returns to step S10. On the other hand, if it is determined that the termination operation has been performed (YES in step S18), the process proceeds to END, and the series of processes in measuring device 20 ends.

[0078] [Processing Flow in Portable Terminal Device] Figure 11 is a flowchart showing an example of the processing procedure in portable information terminal 30. Referring to Figure 3 together with Figure 11, when application software for performing vibration measurement using measuring instrument 20 is started on portable information terminal 30 and an instruction to start measurement is given in the application software, processor 32 executes a predetermined initialization process (step S30). The initialization process includes, for example, establishing communication with measuring instrument 20 and performing a predetermined reset process.

[0079] Next, based on the information received via the input device 35, the processor 32 sets the bearing model number of the rolling bearing 15 to be measured, the rotational speed (or rotational frequency) during measurement, the judgment reference value for determining the vibration state based on the measurement data, the tolerance range, the number of peaks to be acquired, and whether or not to execute the first to third processes (step S32).

[0080] Next, processor 32 reads from memory 33 the specification data of the bearing corresponding to the set bearing model number, and calculates the characteristic frequency of rolling bearing 15 to be measured using the specification data and the rotational frequency calculated from the set rotational speed, using the above equations (1) to (3) (step S34). Processor 32 calculates the allowable range for each part based on the values ​​calculated in step S34 and the allowable range input by the user in step S32 (step S36). Thereafter, processor 32 causes communication device 36 to send a measurement start signal to measuring instrument 20 (step S38).

[0081] When the measurement start signal is sent to measuring device 20, processor 32 determines whether measurement data has been received from measuring device 20 (step S40). If measurement data is received from measuring device 20 (YES in step S40), processor 32 stores the received measurement data in memory 33 (step S42). If measurement data cannot be received from measuring device 20 (NO in step S40), processor 32 repeats the process of step S38.

[0082] Processor 32 reads data from memory 33 and performs frequency analysis on the data measured by measuring instrument 20 (step S44). Specifically, FFT processing is performed on the time-series acceleration data measured by measuring instrument 20 to obtain a frequency spectrum of the measured acceleration data. Processor 32 extracts peaks from the obtained frequency spectrum in descending order of acceleration, and obtains the peak accelerations and peak frequencies of the extracted peaks (step S46). Processor 32 determines whether the number of peaks for which the peak accelerations and peak frequencies have been obtained has reached a set number of peaks (step S48). If the number of peaks for which the peak accelerations and frequencies have been obtained has not reached the set number of peaks (NO in step S48), the process of step S46 is repeated.

[0083] In step S50, if the number of peaks for which peak accelerations and peak frequencies have been obtained reaches the set number of peaks (YES in step S48), the processor 32 determines the vibration state of each peak based on the judgment reference value set in step S32 and the peak acceleration of the peak obtained in step S46.

[0084] Next, for the peaks extracted in step S46, processor 32 identifies candidate parts corresponding to the peak frequencies of each peak. Specifically, for each extracted peak, processor 32 identifies candidate parts for that peak based on whether the peak frequency is within the allowable range for that part (step S52). The candidate parts are, for example, parts of rolling bearing 15 (inner ring, outer ring, and rolling elements) and a rotating shaft that exhibits an abnormality due to shaft imbalance and misalignment.

[0085] If processor 32 has identified a candidate site for the peak extracted in step S46 (YES in step S52), processor 32 causes display device 34 to display the candidate site (step S54). If processor 32 has not identified a candidate site (NO in step S52), processor 32 proceeds to step S68.

[0086] Next, the processor 32 determines whether or not execution of the first process was set in step S32 (step S56). If execution of the first process was set (YES in step S56), the processor 32 executes the first process (step S58). Specifically, the processor 32 excludes from the candidate regions identified in step S52 any region in which a peak of a higher-order component was detected but no peak of a lower-order component was detected. If execution of the first process was not set (NO in step S56), the processor 32 proceeds to step S60 without executing the first process.

[0087] The processor 32 determines whether execution of the second process is set in step S32 (step S60). If execution of the second process is set (YES in step S60), the processor 32 executes the second process (step S62). Specifically, for a region identified in step S52 as a candidate region in which a peak of a lower-order component corresponding to a peak of a higher-order component has been detected, the processor 32 excludes the region from the candidate region if the peak value of the lower-order component peak is equal to or less than the peak value of the higher-order component peak. If execution of the second process is not set (NO in step S60), the processor 32 proceeds to step S64 without executing the second process.

[0088] The processor 32 determines whether execution of the third process is set in step S32 (step S64). If execution of the third process is set (YES in step S64), the processor 32 executes the third process (step S66). Specifically, if there is a peak identified as originating from multiple regions among the peaks extracted in step S46, the processor 32 calculates the difference between the peak frequency of the peak and the characteristic frequency of each of the multiple regions, and prioritizes the multiple regions in order of the smallest difference. If execution of the third process is not set (NO in step S64), the processor 32 proceeds to step S68 without executing the third process. The processor 32 determines the region selected as the candidate region at this time as the abnormal region.

[0089] Then, the processor 32 displays the vibration state determination result and the abnormal part for each of the top 10 peaks in terms of peak value on the display device 34 (step S68). Furthermore, if there is a peak for which priorities have been assigned to multiple abnormal parts as a result of executing the third process, the processor 32 displays the multiple parts on the display device 34 based on the priorities.

[0090] Next, processor 32 determines whether or not the user has performed an end operation to end the measurement (step S72). If the end operation has not been performed (NO in step S72), the process returns to step S32. On the other hand, if the end operation has been performed (YES in step S72), processor 32 proceeds to the end, and the series of processes in mobile information terminal 30 ends.

[0091] As described above, in this embodiment, the validity of a possibly damaged portion identified based on a peak in the frequency spectrum of the measurement data is verified based on its relationship with other peaks in the frequency spectrum. Then, of the identified possibly damaged portions, only those portions with a high probability of being damaged are displayed on the display device 34. This allows the user to easily identify portions with a high probability of an abnormality.

[0092] Furthermore, according to this embodiment, when multiple abnormal portions are identified from one peak, the priorities of the multiple abnormal portions are determined based on the frequency of the one peak and the characteristic frequencies of each of the multiple abnormal portions. Then, the multiple abnormal portions are displayed on the display device 34 in accordance with the priorities. This allows the user to easily identify portions that are highly likely to have an abnormality.

[0093] In this embodiment, a tolerance is set, but the tolerance does not need to be set when the first process and the second process are executed without executing the third process. In this case, a peak at a frequency that coincides with a feature frequency is determined to be a peak resulting from an abnormality in the part corresponding to the feature frequency.

[0094] In addition, the number of peaks to be displayed can be set by the user, allowing for a display that meets the user's wishes. Furthermore, since communication is performed wirelessly between measuring device 20 and portable information terminal 30, the user can check the vibration analysis results from anywhere within the range of wireless communication, as long as measuring device 20 is installed at the measurement target.

[0095] In this embodiment, the control device 31 identifies the locations of the top 10 peaks in terms of peak value and causes the display device 34 to display the abnormal locations corresponding to those peaks, but the control device 31 may also identify the locations of all identified peaks, or cause the display device 34 to display the locations corresponding to all identified peaks.

[0096] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0097] 10 Abnormal part identification system, 15 Measurement object (rolling bearing), 20 Measuring instrument, 30 Portable information terminal, 31 Control device, 32 Processor, 33 Memory, 34 Display device, 35 Input device, 36 Communication device, 102 Acceleration sensor, 104 Anti-aliasing filter, 106 A / D converter, 108 Microcomputer, 110 Memory, 112 Communication module.

Claims

1. A vibration analysis device that receives measurement data from a measuring instrument that measures the vibration of a rotating body and identifies abnormal parts that are parts of the rotating body that may be abnormal, comprising a control device and a display device, wherein the control device: accepts information about the rotating body; performs frequency analysis of the measurement data; calculates, based on the information, each of the characteristic frequencies that arise due to an abnormality in each part of the rotating body; determines, based on each of the characteristic frequencies, a candidate part corresponding to each of the peaks of the frequency spectrum obtained by the frequency analysis; when a first peak corresponding to the characteristic frequency of a specific part is present in the frequency spectrum but a second peak that corresponds to the characteristic frequency of the specific part and is of a lower order than the first peak is not present in the frequency spectrum, excludes the specific part from the candidate parts and determines the remaining candidate parts as the abnormal part; and displays the abnormal part for each peak of the frequency spectrum on the display device.

2. The vibration analysis device according to claim 1, wherein the control device further receives a judgment reference value for judging the vibration state of the rotating body, produces a judgment result for judging the vibration state for each of the peaks of the frequency spectrum based on the peak value of each of the peaks of the frequency spectrum and the judgment reference value, and causes the display device to display the peak value of each of the peaks of the frequency spectrum and the judgment result.

3. A vibration analysis device according to claim 1 or claim 2, wherein the order of the second peak is first order.

4. A vibration analysis device according to claim 1 or claim 2, wherein the control device further excludes the specific part from the candidate parts when the second peak is in the frequency spectrum and the peak value of the second peak is equal to or less than the peak value of the first peak.

5. A vibration analysis device as described in claim 1 or claim 2, wherein the control device further receives an allowable range for each of the characteristic frequencies, and determines the candidate parts depending on whether the frequency of each peak of the frequency spectrum is included in the allowable range.

6. The vibration analysis device according to claim 5, wherein the tolerance range is set by a user of the vibration analysis device.

7. The vibration analysis device according to claim 6, wherein the control device further calculates, when one or more parts are determined as the candidate parts for a third peak included in the frequency spectrum, a difference between each of the characteristic frequencies of the one or more parts and the frequency of the third peak, and causes the display device to display the one or more parts for the third peak in a manner based on the difference.

8. The vibration analysis device according to claim 7, wherein the control device causes the display device to display the one or more parts in ascending order of the difference.

9. A vibration analysis device that receives measurement data from a measuring instrument that measures the vibration of a rotating body and identifies abnormal parts that are candidates for parts of the rotating body that have an abnormality, comprising a control device and a display device, wherein the control device: receives information about the rotating body and an allowable width for each of the characteristic frequencies that arise due to an abnormality in each part of the rotating body calculated based on the information; performs frequency analysis of the measurement data; calculates each of the characteristic frequencies; determines the abnormal part based on whether the frequency of each peak of the frequency spectrum obtained by the frequency analysis is within the allowable width; when one or more parts are determined to be the abnormal part for a fourth peak included in the frequency spectrum, calculates the difference between each of the characteristic frequencies of the one or more parts and the frequency of the fourth peak; and displays the one or more parts as the abnormal part for the fourth peak on the display device in a manner based on the difference.

10. The vibration analysis device according to claim 9, wherein the control device causes the display device to display the one or more parts in ascending order of the difference.

11. A vibration analysis device according to claim 1 or claim 9, wherein the rotating body is a bearing.

12. The vibration analysis device according to claim 11, wherein the information relating to the rotating body includes: a rotational speed or rotational frequency of the bearing; and specifications of the bearing, or a coefficient of the rotational frequency used to calculate the inner ring pass frequency (Ball Pass Frequency of Inner Ring: BPFI), the outer ring pass frequency (Ball Pass Frequency of Outer Ring: BPFO), and the rolling element rotational frequency (Ball Spin Frequency: BSF) of the bearing.

13. A vibration analysis device according to claim 1 or claim 9, further comprising a communication device for wireless communication with said measuring device.

14. An abnormality location identification system comprising: a measuring instrument that measures the vibration of a rotating body that is the measurement target; and a vibration analysis device according to claim 1 or claim 9 that receives measurement data from the measuring instrument and performs vibration analysis.

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