Vibration analysis device and vibration analysis system

Abstract

To provide a vibration analysis device and a vibration analysis system capable of performing vibration analysis while maintaining constant accuracy regardless of the skill level of a user.SOLUTION: A vibration analysis device 1 diagnoses a machine state based on vibrations detected by a measuring device 2. A setting unit 12 sets a target to be diagnosed, a rotational speed, and a determination reference value. A communication unit 13 communicates with the measuring device 2, transmits a trigger for starting vibration measurement to the measuring device 2, and receives vibration waveform data from the measuring device 2. A condition determination unit 16 determines a diagnosis condition from information on the target to be diagnosed. An analysis unit 17 frequency-analyzes data input from the measuring device 2. An abnormality determination unit 11 performs abnormality determination of the target to be diagnosed based on the determination reference value.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a vibration analysis device and a vibration analysis system.

Background Art

[0002] A vibration analysis device that measures vibrations generated in a rotating body and diagnoses faults and the like is known. For example, Japanese Patent Application Laid-Open No. 2016-61752 (Patent Document 1) discloses a diagnostic device that performs vibration analysis by appropriately setting the bandwidth of a frequency filter according to the installation status of a rotating body to be diagnosed. Further, Japanese Patent Application Laid-Open No. 2016-24007 (Patent Document 2) introduces a technique for diagnosing a rolling bearing, determining the presence or absence of abnormalities in an inner ring, an outer ring, rolling elements, a cage, etc., and displaying the determination result in characters or symbols on a portable information terminal. Also, Japanese Patent Application Laid-Open No. 2017-219469 (Patent Document 3) discloses a condition monitoring device that determines the presence or absence of abnormalities based on whether the bearing damage frequency is equal to the peak of the envelope spectrum. This condition monitoring device divides a vibration waveform with a plurality of frequency filters and diagnoses the degree of damage to a diagnosed part from effective values obtained for each frequency band.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] For the maintenance of various devices, a simple vibration analysis device that measures the vibrations of a rotating body such as a bearing or a shaft and determines the presence or absence of abnormalities is convenient for an operator.

[0005] Such a simple vibration analysis device has a simple structure and is easy to introduce. Therefore, since the threshold for introducing vibration analysis is low, many users of simple vibration analysis devices often have no experience in vibration analysis. In vibration measurement, it is common to display a frequency analysis result graph (frequency spectrum) in which the signal from an acceleration sensor is frequency-analyzed and the acceleration for each frequency is graphed. However, if there is no experience in vibration analysis, it is difficult to grasp the health state of the rotating body from the results. Also, in order to accurately determine abnormalities in bearings and shafts, it is necessary to perform appropriate signal processing on the vibration data obtained under appropriate measurement conditions and then perform frequency analysis. However, beginners in vibration analysis cannot set such appropriate measurement conditions and signal processing. Therefore, beginners in vibration analysis may make inappropriate settings for machine abnormality determination and miss signs that can be detected as abnormalities if appropriate settings are made. Also, despite showing signs of abnormality, there may be cases where it is misjudged as normal.

[0006] In conventional vibration analysis devices, regardless of the rotational speed and installation status of the diagnostic target, the measurement time, sampling frequency, or bandwidth of the frequency filter is fixed, or the user can freely select them. However, as the degree of freedom increases, optimal settings must be considered, and knowledge of vibration analysis is required of the user.

[0007] To diagnose the health state of a bearing by vibration, generally, it is necessary to confirm whether the peaks appearing in the envelope spectrum are due to the vibration generated from the bearing. There is also a method of simply quantifying or symbolizing the determination result and displaying it, but since it is difficult to understand which peak in the spectrum was used for the determination, it is difficult to evaluate the consistency between the spectrum and the determination result.

[0008] An object of the present disclosure is to provide a vibration analysis device and a vibration analysis system capable of performing vibration analysis with a certain level of accuracy regardless of the proficiency of the user.

Means for Solving the Problems

[0009] The present disclosure relates to a vibration analysis device that diagnoses a mechanical state based on detected vibrations. The vibration analysis device includes a setting unit that sets a diagnosis target, a rotation speed, and a determination reference value, a condition determination unit that determines diagnosis conditions from information on the diagnosis target, an analysis unit that performs frequency analysis on input data, and an abnormality determination unit that performs an abnormality determination on the diagnosis target based on the determination reference value.

[0010] In another aspect, the present disclosure is a vibration analysis system including a measuring instrument that measures vibrations of a diagnosis target and the vibration analysis device described above. The vibration analysis device is realized by application software operating on a portable information terminal.

Advantages of the Invention

[0011] According to the vibration measurement device of the present disclosure, appropriate measurement conditions and signal processing are set semi-automatically according to the part and rotation speed of the diagnosis target. In addition, the health state of the rotating body, which can be understood from the results obtained from the vibration measurement, is clearly shown. Therefore, vibration analysis can be performed with a certain degree of accuracy even by beginners in vibration analysis.

Brief Description of the Drawings

[0012]

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Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

[0014] FIG. 1 is a diagram showing the configuration of the vibration analysis system according to the present embodiment. The vibration analysis system 100 shown in FIG. 1 includes a measuring instrument 2 for measuring vibrations of a diagnosis target and a vibration analysis device. This vibration analysis device is realized by application software operating on the mobile information terminal 1.

[0015] The mobile information terminal 1 and the measuring instrument 2 are configured to communicate wirelessly with each other.

[0016] Note that, as shown in FIG. 16 later, the mobile information terminal 1A and the measuring instrument 2A may be configured to communicate with each other by wire.

[0017] FIG. 2 is a block diagram showing the configuration of the measuring instrument 2. The measuring instrument 2 shown in FIG. 2 includes a microcomputer 21, a memory 22, a communication module 23, an A / D converter 24, an anti-aliasing filter 25, and an acceleration sensor 26.

[0018] The measuring instrument 2 is installed on a rotating device and measures vibrations caused by at least one of a bearing, a gear, and a rotating shaft, which are diagnostic targets included in the rotating device. The acceleration sensor 26 detects vibrations as acceleration signals. The A / D converter 24 converts the acceleration signals detected by the acceleration sensor 26 into digital signals. The anti-aliasing filter 25 limits the acceleration signals to a band corresponding to the sampling frequency of the A / D converter 24. The microcomputer 21 stores a digital signal indicating a vibration waveform for a certain period in the memory 22, and when it can communicate with the mobile information terminal 1, reads out the vibration waveform from the memory 22 and transmits it to the mobile information terminal 1 by the communication module 23.

[0019] FIG. 3 is a functional block diagram of functions realized by application software in the mobile information terminal 1.

[0020] The mobile information terminal 1 shown in FIG. 3 functions as a vibration analysis device when application software is installed. Hereinafter, the mobile information terminal 1 is also referred to as a vibration analysis device 1. The vibration analysis device 1 includes an abnormality determination unit 11, a setting unit 12, a communication unit 13, a display unit 14, a database unit 15, a condition determination unit 16, and an analysis unit 17.

[0021] The vibration analysis device 1 diagnoses the mechanical state based on the vibration detected by the measuring instrument 2. The setting unit 12 sets the diagnosis target, the rotational speed, and the determination reference value. The communication unit 13 communicates with the measuring instrument 2, transmits a trigger for starting vibration measurement to the measuring instrument 2, and receives vibration waveform data from the measuring instrument 2. The condition determination unit 16 determines the diagnosis conditions from the information of the diagnosis target. The analysis unit 17 performs frequency analysis on the data input from the measuring instrument 2. The abnormality determination unit 11 performs an abnormality determination on the diagnosis target based on the determination reference value. The abnormality determination unit 11 is, for example, a central processing unit (CPU) that executes application software.

[0022] The database unit 15 stores parameters for the abnormality determination unit 11 to identify the damaged part of the diagnosis target. For example, this parameter includes the rotational speed of the bearing. This parameter further stores the specifications of the bearing, or coefficients of a mathematical formula (shown in FIG. 12 later) for calculating the vibration frequency (BPFI) caused by an inner ring damage of the bearing, the vibration frequency (BPFO) caused by an outer ring damage of the bearing, and the vibration frequency (BSF) caused by a rolling element damage of the bearing based on the rotational speed.

[0023] FIG. 4 is a flowchart for explaining the measurement process in the measuring instrument 2. The measurement process will be described with reference to FIGS. 2 and 4.

[0024] In step S1, an initialization process is performed.

[0025] In step S2, the microcomputer 21 determines whether a measurement start signal has been received. If not received, the process returns to step S1. When the measurement start signal is received (YES in S2), in step S3, the microcomputer 21 reads the output signal of the acceleration sensor 26 via the A / D converter 24 and stores the data that has become a digital signal in the memory 22.

[0026] In step S5, the microcomputer 21 determines whether a predetermined number of data has been acquired. If the acquired data has not reached the predetermined number (NO in S5), the microcomputer 21 returns the process to step S3 to continue acquiring data.

[0027] If the acquired data has reached the predetermined number (YES in S5), in step S6, the microcomputer 21 reads the acquired data from the memory 22 and transmits it to the portable information terminal 1. Then, in step S7, the microcomputer 21 determines whether an end operation of the measurement has been performed.

[0028] If the end operation of the measurement has not been performed (NO in S7), the microcomputer 21 executes the process from step S1 again. If the end operation of the measurement has been performed (YES in S7), the microcomputer 21 ends the measurement process by the measuring instrument 2.

[0029] FIG. 5 is a flowchart for explaining the operation of a vibration analysis device realized by application software for vibration analysis executed inside the portable information terminal 1.

[0030] The operation of the vibration analysis device will be described with reference to FIGS. 3 and 5. First, in step S11, an initialization process is executed. Then, in step S12, based on the user's operation, the setting unit 12 sets the bearing model number, rotational speed, determination value, etc. At this time, the user inputs the rotational speed of the diagnosis target and the inside of the bearing various element and the determination value (threshold value) on the application software.

[0031] Then, in step S13, the abnormality determination unit 11 reads out the specifications of the selected bearing model number from the database unit 15 and calculates the damage frequency for each part of the target device based on the read specifications. Then, in step S14, the abnormality determination unit 11 executes a measurement condition setting process.

[0032] The simple vibration analyzer 1 described in this embodiment performs storage and calculation processing of measured vibration data on a portable information terminal.

[0033] At this time, the data volume is proportional to the data length obtained from the product of the sampling frequency and the measurement time. When the sampling frequency and the measurement time can be freely set, the values of the sampling frequency and the measurement time are set from the rotational speed of the rotating body to be diagnosed and the necessary frequency band. However, since it is a portable information terminal, it is essential to set considering the limitations of data processing speed and storage capacity, and this setting is difficult for beginners in vibration analysis.

[0034] In this embodiment, the data length of the measurement data is fixed to a number in which the limitations of data processing speed and storage capacity are considered in advance.

[0035] Then, a plurality of diagnostic conditions in which the sampling frequency and the measurement time are adjusted so that the number of data is equal are stored in the application software in advance. In this embodiment, three types of low speed, medium speed, and high speed are stored.

[0036] And, by automatically changing the sampling frequency and the measurement time according to the rotational speed of the diagnosis target and the value obtained from the bearing various originally, the user can set the sampling frequency and the measurement time without being aware of the limitations of the device. The details of the process in step S14 will be described later with reference to FIG. 6.

[0037] When the measurement conditions are set in step S14, in step S15, the portable information terminal 1 transmits a measurement start signal to the measuring instrument 2. Then, the measurement is started in the measuring instrument 2, and the data measured after the measurement is transmitted from the measuring instrument 2.

[0038] In step S16, the abnormality determination unit 11 determines whether the communication unit 13 has received data from the measuring instrument 2. If received (YES in S16), the abnormality determination unit 11 stores the data in the memory. Then in step S18, the abnormality determination unit 11 determines whether a predetermined number of data has been acquired.

[0039] If a predetermined number of data has not been acquired (NO in S18), the processing after step S16 is executed again and the reception continues. If a predetermined number of data has been acquired (YES in S18), in step S19, the abnormality determination unit 11 reads the data from the memory and calculates the frequency spectrum and the envelope spectrum.

[0040] In step S20, the abnormality determination unit 11 determines whether there are signs indicating abnormalities such as damaged parts of the bearing, misalignment, and shaft imbalance. In step S21, the determination result and the waveform are displayed on the display unit 14.

[0041] Then, in step S22, the abnormality determination unit 11 determines whether an end operation of the measurement has been performed.

[0042] If the end operation of the measurement has not been performed (NO in S22), the abnormality determination unit 11 executes the processing from step S12 again. If the end operation of the measurement has been performed (YES in S22), the abnormality determination unit 11 ends the vibration analysis process.

[0043] Figure 6 is a flowchart showing the details of the measurement condition setting process in step S14.

[0044] In this embodiment, when automatically setting the diagnostic conditions, the rotational speed of the object to be diagnosed and the specifications of the bearing are required. After performing the initialization process (S11), the user is made to input the rotational speed R and the bearing specifications (S12). The specifications may also be stored in advance before executing the process of automatically setting the diagnostic conditions. Then, the damage frequency for each part of the bearing is calculated from the input rotational speed R and the bearing specifications (S13). The rotational frequency R and the inner ring damage frequency BPFI, which is one of the damage frequencies obtained in step S13, are read out (S31). Next, in step S32, the abnormality determination unit 11 causes the user to select on the application software whether the object to be diagnosed is (A) damage vibration of the bearing or gear, or (B) mechanical vibration such as improper assembly. While holding the rotational speed R read out in step S31 and the value of the calculated inner ring damage frequency BPFI, the process proceeds to either the subroutine "Condition Determination A (S33)" or "Condition Determination B (S34)" depending on the diagnostic object selected by the user (S32). The diagnostic object selected by the user in step S32 is either A: damage to the bearing or gear, or B: mechanical vibration such as improper assembly.

[0045] When the user selects (A) damage vibration of the bearing or gear as the diagnostic object, the abnormality determination unit 11, in step S33, selects one diagnostic condition from two values of the rotational speed of the diagnostic object and the bearing inner ring damage frequency obtained from the bearing specifications. various On the other hand, when the user selects (B) mechanical vibration such as improper assembly as the diagnostic object, the abnormality determination unit 11, in step S34, selects one diagnostic condition from the rotational speed of the diagnostic object.

[0046]

[0047] ​When the diagnosis target is A: damage to bearings or gears, it is preferable to check the envelope spectrum, which is the FFT result of the envelope waveform obtained by performing envelope (envelope line) processing on the time waveform. Also, when the diagnosis target is B: mechanical vibrations such as assembly defects (e.g., misalignment, mis-coupling, looseness, runout), it is preferable to check the frequency spectrum, which is the FFT result of the time waveform. Therefore, when the diagnosis target is the former, conditional determination A is performed, and when it is the latter, conditional determination B is performed, and the processing is carried out in separate subroutines.

[0048] The details of the processing of the subroutines in steps S33 and S34 will be described later with reference to FIGS. 8 to 10. In step S35, it is determined which of low speed, medium speed, and high speed the diagnostic conditions determined by the subroutine correspond to. If the diagnostic condition is low speed, the setting corresponding to low speed is determined as the recommended setting in step S36. If the diagnostic condition is medium speed, the setting corresponding to medium speed is determined as the recommended setting in step S37. If the diagnostic condition is high speed, the setting corresponding to high speed is determined as the recommended setting in step S38.

[0049] FIG. 7 is a diagram showing diagnostic conditions corresponding to low speed, medium speed, and high speed. The diagnostic conditions corresponding to low speed are sampling frequency fs = 2.56 kHz, measurement time t = 6.4 s. At this time, the data length N (= fs × t) = 16384, the BPF bandwidth fl~fh = 400~800 Hz, the frequency resolution Δf (= 1 / t) = 0.15625 Hz, and the upper limit of the frequency component fmax (= fs / 2.56) = 1 kHz.

[0050] The diagnostic conditions corresponding to medium speed are sampling frequency fs = 12.8 kHz, measurement time t = 1.28 s. At this time, the data length N = 16384, the BPF bandwidth fl~fh = 1k~5 kHz, the frequency resolution Δf = 0.78125 Hz, and the upper limit of the frequency component fmax = 5 kHz.

[0051] The diagnostic conditions for high speed are a sampling frequency fs = 25.6 kHz and a measurement time t = 0.64 s. At this time, the data length N = 16384, the BPF bandwidth fl~fh = 2k~10 kHz, the frequency resolution Δf = 1.5625 Hz, and the upper limit of the frequency component fmax = 10 kHz.

[0052] Subsequently, the abnormality determination unit 11 displays on the display unit 14 (S39) in order to propose the diagnostic conditions determined in any of steps S36 to S38 as the diagnostic conditions recommended to the user, and allows the user to select the diagnostic conditions. Based on this, the user determines the diagnostic conditions (S40). Note that it is preferable that the selected diagnostic conditions can be freely changed by the user later.

[0053] Thereafter, in step S15 of FIG. 5, the vibration of the diagnostic target is measured under the selected diagnostic conditions (S36 to S38), and in steps S19 to S21, spectrum calculation and result display are performed.

[0054] Here, in steps S32 to S38, the reasons for changing the condition determination process and the recommended settings depending on the diagnostic target will be described.

[0055] The elements to be confirmed by vibration analysis differ depending on whether the abnormality of the machine to be diagnosed is due to damage to bearings or gears, or due to assembly defects or the like.

[0056] In the case of bearing or gear damage (S33), impact vibration occurs at the damaged part, so the magnitude and occurrence period of the impact vibration are the elements to be confirmed by vibration analysis. These two elements can be confirmed from the FFT result (envelope spectrum) of the envelope waveform obtained by performing envelope (envelope curve) processing on the time waveform. Specifically, on the envelope spectrum, the rotational speed and the internal variousA peak that coincides with the frequency obtained from the original signal (characteristic frequency) appears. If the process is performed so that the frequency components of the impact vibration before performing the envelope processing are extracted by a frequency filter (BPF in the present embodiment), the peaks other than the characteristic frequency appearing in the envelope spectrum are reduced, so that the peak of the characteristic frequency becomes relatively easy to confirm. However, since there is an upper limit to the frequency that can appear as a peak in the envelope spectrum, it is necessary to ensure that the inner ring damage frequency, which is the highest characteristic frequency, does not exceed the upper limit (to be shown later in S51, S52, S53 of FIG. 8). Also, in order to detect damage to bearings and gears at an early stage, it is preferable that the bandwidth of the BPF includes higher frequency components as much as possible (to be shown later in S55 of FIG. 8). In the subroutine of the conditional branch A (to be described later in FIG. 8) for setting the diagnostic conditions when the diagnosis target is damage to bearings and gears, the optimal diagnostic conditions are selected based on the upper limit of the frequency of reliable peaks and the branch flow considering early detection of damage.

[0057] On the other hand, in the case of poor assembly or the like, the forced vibration caused by rotation becomes larger than normal, so the magnitude and frequency of the forced vibration component are elements to be confirmed by vibration analysis. These two elements can be confirmed from the FFT result (frequency spectrum) of the time waveform. Specifically, a peak that coincides with the frequency obtained from the rotational speed (rotational frequency) appears on the frequency spectrum. However, since there is an upper limit to the frequency components of the time waveform due to the sampling theorem in the frequency spectrum, it is necessary to ensure that the rotational frequency does not exceed the upper limit. Also, since the frequency resolution of the frequency spectrum improves in proportion to the measurement time (the numerical value is inversely proportional), it is preferable that the measurement time is longer. For mechanical vibration in the case where the diagnosis target is poor assembly or the like diagnosis of In the subroutine of the conditional branch B (to be described later in FIG. 9) for setting the diagnostic conditions, the optimal diagnostic conditions are set based on a branch flow considering that peaks up to the sixth-order component of the rotational frequency appear in the frequency spectrum.

[0058] FIG. 8 is a flowchart of a subroutine (condition determination A) for determining diagnostic conditions when diagnosing damage to a bearing or a gear.

[0059] When diagnosing damage to bearings or gears (condition determination A), check the peaks that appear in the envelope spectrum. It is better to rotate as many diagnostic objects as possible during measurement, as the peaks indicating damage will become sharper and easier to diagnose. To include the minimum number of rotations required for diagnosis during measurement (to ensure the sharpness of the peaks in the envelope spectrum), for each of the three diagnostic conditions (low speed, medium speed, high speed) in this embodiment, the branch value of the rotational speed in S51 is set to 300 min -1 so that it enters the measurement time three or more rotations during measurement. For example, if it rotates three times in 0.64 seconds under high-speed conditions, then 3 rev / 0.64 s = 281.25 rev / min, which is less than 300 min -1 When the rotational speed exceeds 300 min -1 (YES in S51), it proceeds to the process of determining whether it is medium-speed or high-speed condition (S52, S53), and when it is 300 min -1 or less (NO in S51), it proceeds to the process of determining whether it is low-speed or medium-speed condition (S56).

[0060] The envelope spectrum is a graph representing the occurrence interval of impact vibrations in the frequency domain. When the occurrence interval of impact vibrations is extremely short, the separation between impact waveforms becomes unclear, and the peaks indicating the impact waveforms do not appear in the envelope spectrum. The maximum value of the frequency of the peaks that appear in the envelope spectrum is obtained from the reciprocal of the limit value (period) of the occurrence interval of vibrations. The limit value of the occurrence interval is generally the value obtained by dividing a value around 10 (number of data) by the sampling frequency. In this embodiment, considering the reciprocal of the value obtained by dividing the number of data 8 by the sampling frequency (12800 Hz / 8 = 1600 Hz, 25600 Hz / 8 = 3200 Hz) and the error in rotational speed related to motor control, etc., the maximum frequencies of the envelope spectrum at medium speed and high speed are determined to be 1500 Hz and 3000 Hz respectively.

[0061] When the frequency (characteristic frequency) indicating the damage of the bearing and the gear exceeds the above-mentioned maximum frequency, the peak of the characteristic frequency does not appear in the envelope spectrum and diagnosis cannot be performed. Therefore, depending on whether the inner ring damage frequency (BPFI), which is the highest frequency among the characteristic frequencies, exceeds the maximum frequencies at medium speed and high speed (S52; BPFI > 1500 Hz, S53; BPFI > 3000 Hz), the diagnosis conditions are classified into medium speed or high speed.

[0062] At rotational speeds that do not satisfy BPFI > 1500 Hz (NO in S52), diagnosis can be performed under either medium speed or high speed conditions. The frequency band of the vibration generated by bearing damage generally falls within the several kHz band. Since especially initial damage is likely to appear in the higher frequency side frequency band, if the user wants to detect bearing damage with high sensitivity (YES in S55), it is preferable to perform diagnosis under high speed conditions (S59) even at rotational speeds that can be measured under medium speed conditions.

[0063] As shown in FIG. 7, in the frequency spectrum under medium speed conditions (S58), the maximum frequency is 5 kHz and the BPF band is 1 kHz to 5 kHz, whereas in the frequency spectrum under high speed conditions (S59), the maximum frequency is 10 kHz and the BPF band is 2 kHz to 10 kHz. Therefore, since diagnosis can be performed under a frequency band that has a margin in the several kHz band, which is the frequency band of bearing damage, under high speed conditions (S59), there is a higher possibility of detecting bearing damage than under medium speed conditions (S58).

[0064] When the bearing damage progresses to the final stage, the frequency band of the bearing damage moves to a lower frequency band. In FIG. 7, the maximum frequency and the BPF bandwidth outside the frequency band of the bearing damage in the low speed condition are for facilitating the detection of the bearing in the final stage. Also, since the progress speed of the damage slows down when the rotational speed of the diagnosis target is low, even if it is determined in daily diagnosis that the bearing is approaching the final stage, there is a certain time allowance for bearing replacement.

[0065] In vibration diagnosis, early anomaly detection is preferred. Therefore, in the process of determining whether the conditions are low speed or medium speed (S56), the rotational speed at which diagnosis can be minimally performed under medium speed conditions (S58) (150 min-1 If it is larger (than a certain value), the medium-speed condition (S58) is selected.

[0066] Also, at a rotational speed that satisfies BPFI > 3000 Hz (YES in S53), no peak indicating inner ring damage appears in the envelope spectrum. Therefore, when this condition is satisfied, a warning message is displayed (S54) to inform the user whether the target diagnosis is possible. Depending on the rotational speed, bearing, and gear, peaks indicating damage other than inner ring damage may appear in the envelope spectrum, and it cannot be said that no diagnosis is possible at all. Therefore, in the warning message (S54), it is clearly stated which peak indicating damage does not appear to inform the user that the accuracy of the diagnosis may decrease.

[0067] When the diagnostic condition is determined in any of steps S57, S58, or S59, the setting to preferentially display the envelope spectrum is stored in step S60, the processing of the subroutine of condition determination A ends, and then the processing of step S35 in FIG. 6 is executed.

[0068] FIG. 9 is a flowchart of a subroutine (condition determination B) for determining diagnostic conditions when diagnosing mechanical vibrations such as assembly defects.

[0069] When diagnosing mechanical vibrations such as assembly defects, the peaks appearing in the frequency spectrum are checked. Since mechanical vibrations are caused by rotation, the magnitude and frequency of the vibrations (rotation frequency = rotational speed min -1 / (60) appears as a peak. When determining assembly defects from the peak of the rotational frequency, check the appearance of the harmonic components of the rotational frequency. For example, in the case of misalignment, the peak of the second-order component is often larger than that of the first-order component in the frequency spectrum. Since the frequency resolution of the frequency spectrum improves (the line spacing of the frequency spectrum becomes finer) in proportion to the measurement time length, it is preferable to have a longer measurement time. However, according to the sampling theorem, it is not possible to display frequency components below half of the sampling frequency, so this point needs to be considered. Generally, the value obtained by dividing the sampling frequency by 2.56 is used as the upper limit. In this embodiment, considering the frequency upper limit, the diagnostic conditions are determined based on the rotational speed in steps S71, S72, and S73 so that peaks up to at least the sixth-order component of the rotational frequency appear in the frequency spectrum. Similar to the flowchart shown in FIG. 8, when the user inputs a rotational speed at which peaks up to the sixth-order component of the rotational frequency do not appear (YES in S73), a warning message indicating this is displayed (S74).

[0070] When the diagnostic conditions are determined in any of steps S75, S76, or S77, the setting is stored so as to preferentially display the frequency spectrum in step S78, the processing of the subroutine of condition determination B ends, and then the processing of step S35 in FIG. 6 is executed.

[0071] FIG. 10 is a flowchart of a subroutine (condition determination B) for determining the diagnostic conditions of a modified example of FIG. 9 considering damage to bearings and gears.

[0072] In the condition determination of FIG. 9, although damage to bearings and gears can be confirmed from the envelope spectrum, due to the limitation of the frequency at which the peaks indicating the impact waveform disappear in the envelope spectrum, depending on the rotational speed of the diagnostic target and the type of bearing / gear, the peaks indicating damage may not appear. Therefore, the selection process of diagnostic conditions A and B is separated between the damage vibration of the bearing or gear and the mechanical vibration. However, in the case of mechanical vibration where impact vibration is introduced every rotation, a peak appears at the rotational frequency in the envelope spectrum. With the envelope spectrum, peaks indicating damage to bearings and gears can also be confirmed. As described above, the diagnostic conditions are judged by the rotational speed so that peaks up to at least the sixth harmonic component of the rotational frequency appear in the frequency spectrum. However, rotational speeds at which peaks indicating damage to bearings and gears enter this diagnostic condition to some extent may also be considered. An example thereof is described below.

[0073] The bearing held by the portable information terminal (application) various Take the ratio of the rotational frequency to the inner ring damage frequency in the original, and assume that the inner ring damage frequency becomes 20 times the rotational frequency at maximum. When the maximum frequency (2560 Hz / 8 = 320 Hz) of the envelope spectrum in the case of low-speed diagnostic conditions matches the inner ring damage frequency, the rotational frequency is 320 / 20 = 16 Hz from the previous ratio, so the upper limit of the rotational speed is 960 min -1 If it is assumed that the rotational speed actually increases or decreases even if it is controlled, and considering a 5% increase or decrease, the approximate upper limit is 900 min -1 (S91). Similarly, when obtaining the determination values for medium speed and high speed, it is 4500 min -1 (S92), 9000 min -1 (S93).

[0074] By using such a determination, it becomes possible to confirm damage to bearings and gears using the envelope spectrum even in condition determination B. However, since condition determination B is not optimally set for detecting damage to bearings or gears like condition determination A, it is inferior to condition determination A in terms of detecting damage at an early stage. The flowchart of FIG. 10 may be used as an alternative to the flowchart of FIG. 9. Further, as an option when mainly diagnosing mechanical vibration but also minimally diagnosing bearings, in addition to the two branches of condition determination A shown in FIG. 8 and condition determination B shown in FIG. 9, the process of FIG. 10 may be added as condition C, and the branch at step S32 may be made into a three-way branch of condition determinations A to C.

[0075] FIG. 11 is a diagram showing an example of a setting screen for measurement conditions and the like displayed on the display unit 14. For the bearing type, rotational speed, and sensitivity required in step S12 of FIG. 4, the values set in the left half of this screen are used. When values for the bearing type, rotational speed, and sensitivity are input, the vibration analyzer 1 automatically selects optimal diagnostic conditions and displays them in the right half of the screen. The selected diagnostic conditions are not limited, but it is preferable that they are not fixed and can be freely changed by the user after automatic selection.

[0076] FIG. 12 is a diagram showing calculation formulas for bearing characteristic frequencies (BPFO, BPFI, BSF). The database unit 15 in FIG. 1 stores parameters for the abnormality determination unit 11 to identify the damage location of the diagnosis target.

[0077] When this parameter is the specifications of the bearing, the abnormality determination unit 11 uses an equation as shown in FIG. 12 to calculate the vibration frequency (BPFI) caused by an inner ring injury of the bearing, the vibration frequency (BPFO) caused by an outer ring injury of the bearing, and the vibration frequency (BSF) caused by a rolling element injury of the bearing from the bearing specifications (pitch circle diameter D of the bearing, diameter d of the rolling element, contact angle α of the rolling element, number Z of rolling elements) and the rotational frequency f0 of the inner ring shaft.

[0078] Also, this parameter may be a coefficient of an equation calculated in advance corresponding to the bearing model number. In the case of the coefficient in (Equation 1) of FIG. 12, it is Z / 2*(1 + d / D*cosα), and multiplying this coefficient by the rotational frequency f0 gives BPFI. In the case of the coefficient in (Equation 2) of FIG. 12, it is Z / 2*(1 - d / D*cosα), and multiplying this coefficient by the rotational frequency f0 gives BPFO. In the case of the coefficient in (Equation 3) of FIG. 12, it is Z / (2d)*(1 - (d / D) 2 *cos 2 α), and multiplying this coefficient by the rotational frequency f0 gives BSF.

[0079] FIG. 13 is a diagram showing a display example of the frequency spectrum displayed on the display unit 14. The abnormality determination unit 11 displays the measured vibration frequency spectrum and envelope spectrum on the display unit 14. Depending on the diagnostic target selected in step S32 of FIG. 6 (whether it is the damage vibration of a bearing or a gear, or the vibration of a machine), as shown in step S60 of FIG. 8, step S78 of FIG. 9, and step S98 of FIG. 10, the spectrum to be preferentially displayed is switched. Also, although not limited, it is preferable that the spectrum preferentially displayed automatically can be freely switched by the user to other spectra later.

[0080] Simply displaying the spectrum alone makes it difficult to tell whether the peak of the characteristic frequency appears. Therefore, on the spectrum display screen shown in FIG. 13, a range ( - 10% to 5% of the characteristic frequency) where the peak of the characteristic frequency including harmonics is assumed to appear is displayed as a colored band. In the example of FIG. 13, a threshold value W2 is displayed for the FFT spectrum W1. In addition to this, the shaft rotation frequency is selected as the characteristic frequency, and the band corresponding to the harmonics up to the 3rd order of this characteristic frequency is shown. By checking the presence or absence of the peak of the FFT spectrum W1 in this band, even a beginner can visually determine whether the damage characteristics are in the FFT spectrum W1. That is, with a screen like FIG. 13, it is possible to clearly display whether the value of the spectrum W1 included in the damage range exceeds the threshold value W2, which is the set determination value.

[0081] FIG. 14 is a diagram showing an example of the display of the envelope spectrum displayed on the display unit 14. In the example of FIG. 14, a threshold value W2 is displayed for the FFT spectrum W1. In addition to this, as characteristic frequencies, the outer ring damage frequency, the inner ring damage frequency, and the rolling element damage frequency are selected, and the bands corresponding to the first fundamental waves of each of these are shown with different hatchings. On the actual screen, a band indicating a range where it is presumed that peaks indicating damage to parts such as the rotation frequency or the bearing characteristic frequency will appear in the spectrum is displayed in different colors. By checking the presence or absence of the peak of the FFT spectrum W1 in this band, even a beginner can visually determine whether the characteristics of the damage are present in the FFT spectrum W1.

[0082] In the present embodiment, vibration measurement is performed with the measuring instrument 2 by applying the diagnostic conditions determined in step S14 of FIG. 5. When (A) the damage vibration of the bearing or gear is selected in step S32 of FIG. 6, in step S21, an envelope spectrum as shown in FIG. 13 is displayed on the display unit 14. On the other hand, when (B) mechanical vibration such as poor assembly is selected in step S32 of FIG. 6, in step S21, a frequency spectrum as shown in FIG. 14 is displayed on the display unit 14. The display here is only to preferentially display either the envelope spectrum or the frequency spectrum, and it is preferable that the user can freely switch between them.

[0083] FIG. 15 is a diagram showing an example of an analysis report output from the portable information terminal 1. In the present embodiment, the measurement results are displayed on the portable information terminal 1. When the size of the portable information terminal 1 is small, it is burdensome for the user to check the diagnosis result on the screen. Also, it takes time to operate the terminal every time to recheck the results, and even if the results can be displayed, it is difficult to share the information by showing the screen. To solve this problem, the abnormality determination unit 11 is configured to output a report in which the diagnosis result and the history of data measured so far can be confirmed via the communication unit 13 in an image data format (such as PDF or PNG). The output report can be displayed on a large screen by a personal computer or printed by a printer. In FIG. 15, the envelope spectrum is displayed in the upper part, and the trend graph of the first peak of the characteristic frequency is displayed in the lower part. This is not the only way; the upper spectrum may be a frequency spectrum, or the lower trend graph may be a list of physical quantities (such as effective value, maximum value of absolute value, crest factor, etc.) obtained from the measured vibration data. Also, the frequency spectrum may be displayed in the upper part and the envelope spectrum in the lower part, or both the upper and lower parts may be trend graphs.

[0084] As described above, according to the present embodiment, the application software operating on the portable information terminal can perform settings for vibration measurement, control of the measuring instrument, analysis of data, and result display.

[0085] FIG. 16 is a diagram showing a modified example of the vibration analysis system. As shown in FIG. 16, the portable information terminal 1A and the measuring instrument 2A may be configured such that they communicate with each other by wire.

[0086] Although not shown, various modified examples as described below may be incorporated.

[0087] [Extension of measurement time] As also described in the description of FIG. 8, the object to be diagnosed should be rotated as many times as possible during measurement so that the peak indicating damage becomes sharp and it becomes easier to diagnose. When the diagnosis condition is high speed, about 280 min-1 If the rotation speed is not as above, diagnosis will be difficult. For large bearings with a slow rotation speed, since it takes time for the delivery and replacement preparation of the bearings, it is often desired to detect bearing damage at an early stage. In the present embodiment, it is preferable to set the diagnosis conditions to medium speed or high speed conditions in order to detect damage at an early stage, but diagnosis is difficult due to the influence of the rotation speed described above. Depending on the diagnosis target, there are cases where the vibration measurement and analysis desired by the user cannot be performed due to the data length limitations described in 0032 and 0033. Therefore, if the measurement at medium speed or high speed conditions is repeatedly executed to increase the measurement time to 2.56 seconds or 5.12 seconds, a sufficient measurement time for diagnosis can be secured. However, since the data processing load and data capacity increase as the measurement time becomes longer, attention is required. Therefore, the extension of the measurement time of this method is a function for experienced users rather than the semi-automatic method of setting diagnosis conditions for beginners in vibration analysis shown in FIGS. 8, 9, and 10.

[0088] From the rotation speed input by the user, the measurement time required for diagnosis is obtained. For example, if the rotation speed of the diagnosis target is 150 min -1 and the standard of the minimum number of rotations required for analysis is 3 rotations, then 3 rev * (60 s / 150 rpm) = 1.2 ≒ 1.28 s. When using the measurement time extension function, if the measurement time is set to exceed the sufficient time length for analysis, unnecessary data portions will also be included in the processing and data storage. For example, for the previous rotation speed of 150 min -1 if the measurement time is set to 5.12 s, the time length of the data for which the minimum analysis is possible is 1.28 s, and the data for the remaining 3.84 s becomes unnecessary. If an upper limit of the data length (the product of the measurement time and the sampling frequency) is set in consideration of the data processing load and data capacity, it becomes possible to measure and diagnose bearings and gears rotating at low speed under medium speed and high speed conditions. If a function is provided to automatically set the data length from the rotation speed, even a beginner in vibration analysis can extend the measurement time within the range where the functions of the system and equipment of this patent function properly. This function is a different function from the automatic selection of diagnosis conditions shown in FIGS. 8, 9, and 10, and it is preferable that they are independent functions that can be freely selected by the user.

[0089] [Detailed analysis (changing the BPF range, recomputing the envelope spectrum)] In this embodiment, vibration is measured and diagnosed under three conditions: low speed, medium speed, and high speed. This device can perform vibration analysis with a certain level of accuracy regardless of the user's proficiency. Settings required for vibration analysis are selected from three patterns (low speed, medium speed, high speed) according to the diagnostic target and operating conditions. When performing a detailed vibration analysis, it is preferable not only to diagnose based on these three conditions but also to check whether damage characteristics can be seen in frequency bands other than these conditions. Therefore, the data measured under the selected conditions (raw vibration waveforms without processing) can be stored, and a function can be provided to change the bandwidth of the frequency filter and display the envelope spectrum.

[0090] [Timer measurement] Depending on the diagnostic target, abnormal vibration may occur only for a very short period. If the timing of the abnormal vibration is within a few seconds immediately after pressing the operation button of the machine including the diagnostic target, and when using this device with a short measurement time, it is necessary to press the operation button of the machine and the measurement start button of this device almost simultaneously. In factories, it is often prohibited to perform two-handed simultaneous different operations for safety reasons, and two operators are required to press the buttons simultaneously. To solve this problem, similar to the self-timer of a camera, the user can set the time from pressing the measurement start button of this device to the start of measurement, so that even one operator can aim at the abnormal vibration and perform the measurement.

[0091] [Proposal for remeasurement] In some cases, the rotational speed and the bearing variousIn the diagnostic conditions selected from the beginning, the characteristics of the damage do not appear, and there are cases where the characteristics of the damage appear under diagnostic conditions different from the selected ones. If the frequency band of the vibration due to the damage is not included in the bandwidth of the BPF set for each condition, this case will occur. For example, if the frequency band of the vibration due to the damage is around 1 kHz, it will be outside the bandwidth of 2 kHz to 10 kHz of the BPF under high-speed conditions. Therefore, in this case, peaks indicating damage are unlikely to appear in the envelope spectrum measured under high-speed conditions. On the other hand, peaks indicating damage are likely to appear under medium-speed conditions (BPF is 1 kHz to 5 kHz) that can include information around 1 kHz. Therefore, in order to avoid undetected damage, the rotational speed and the bearing various If, as a result of analyzing the vibration measured under the diagnostic conditions selected from the beginning, no characteristics of damage are found, it is proposed to the user to measure under conditions different from the measured conditions. This proposal is made, for example, by the display on the display unit 14.

[0092] [Selection of Diagnostic Conditions by Data Comparison] As described in the modified example of the above proposal for remeasurement, the rotational speed and the bearing various There are cases where the characteristics of the damage do not appear under the diagnostic conditions selected from the beginning. Such cases are likely to occur in machines where the degree of damage to the diagnostic target is completely unknown and that have been operated to a certain extent. Therefore, the rotational speed and the bearing various Instead of selecting from the beginning, measure the vibration of the diagnostic target under all three conditions of low speed, medium speed, and high speed, and select the condition in which the characteristics indicating damage appear most strongly as the diagnostic condition to be used for future monitoring.

[0093] [Judgment of Damage Characteristics] In the modified example of making a proposal for remeasurement and the modified example of selecting diagnostic conditions by data comparison, methods of making a proposal for remeasurement or selecting diagnostic conditions based on whether the characteristics of the damage are found are described. Here, the method of determining whether the characteristics of the damage are found will be described below.

[0094] In this embodiment, the characteristics of damage are determined from the determination value (threshold value) set by the user. The user inputs the determination value in advance before measurement, and if a peak exceeding that value appears, it is determined that the characteristics of damage are observed. The determination value may be simply applied to the maximum value of the spectrum, or may be applied to the largest value among the peaks indicating damage (such as the rotational frequency and the bearing characteristic frequency).

[0095] When determining from the peak indicating damage, the area of the peak may be considered. The peak indicating damage is obtained from the rotational speed, but the actual rotational speed is often different from the input value. For example, in the case of a motor, slip occurs and the rotational speed slightly decreases. If the rotational speed is different from the input value, a deviation occurs between the theoretical value and the actual peak frequency, and correct determination cannot be made. Therefore, considering the increase or decrease of the rotational speed in advance, the area of the spectrum included in the frequency range where the peak is assumed to appear (for example, -10% to 5% of the characteristic frequency) may be regarded as the area of the peak, and it may be determined whether the characteristics of damage are observed.

[0096] In the above description, the largest peak is picked up to determine whether the characteristics of damage are observed. However, since there are multiple types of peaks indicating damage, such as the rotational frequency and the bearing characteristic frequency, these may be considered. If the number of peaks specified in advance among the peaks indicating damage exceeds the determination value, it may be determined as damage. Also, it may be determined as damage only by a specific peak, such as when the "outer ring damage frequency" exceeds the determination value. At this time, the method of specification may be specified in the source code in advance, or may be a method freely selected by the user on the application software.

[0097] In addition, for products of this type, it is desired that they can be easily attached and detached from the measurement object, but at the same time, measures to prevent dropping are also required. Therefore, when the measuring instrument has a vertically long shape in the vertical direction with respect to the installation surface, a constricted shape with a concave center part of the housing is desirable. Thereby, it becomes easier for a finger to get caught during attachment and detachment, and the risk of dropping can be reduced.

[0098] (Summary) Finally, the present embodiment will be summarized with reference to the drawings again.

[0099] The present embodiment relates to a vibration analysis device that diagnoses the mechanical state based on the detected vibration. The vibration analysis device 1 shown in FIG. 3 includes a setting unit 12 that sets a diagnosis target, a rotation speed, and a determination reference value, a condition determination unit 16 that determines diagnosis conditions from the information of the diagnosis target, an analysis unit 17 that performs frequency analysis on the input data, and an abnormality determination unit (central processing unit) 11 that performs an abnormality determination of the diagnosis target based on the determination reference value.

[0100] Preferably, the diagnosis target includes at least one of a bearing, a gear, and a rotating shaft.

[0101] More preferably, the vibration analysis device 1 further includes a database unit 15 that stores parameters for the abnormality determination unit 11 to specify the damaged part of the diagnosis target. The database unit 15 stores, as parameters, (1) the rotation speed of the bearing and (2) the coefficients of a mathematical formula. This mathematical formula is a formula for calculating the vibration frequency caused by an inner ring damage of the bearing, the vibration frequency caused by an outer ring damage of the bearing, and the vibration frequency caused by a rolling element damage of the bearing based on the specifications of the bearing or the rotation speed.

[0102] More preferably, the information is the rotation speed of the diagnosis target and the inner ring damage frequency of the bearing, and the condition determination unit 16 selects the condition corresponding to the information as the diagnosis condition.

[0103] More preferably, the condition determination unit 16 selects the diagnosis condition from a plurality of conditions in which the sampling frequency and the measurement time are adjusted so that the number of data is equal to each other.

[0104] Preferably, the vibration analysis device 1 further includes a display unit 14. In the combination of the rotation speed of the diagnosis target, the inner ring frequency of the bearing, and the diagnosis condition, if theoretically no peak indicating the damage of the diagnosis target appears in the frequency spectrum or the envelope spectrum, the abnormality determination unit 11 causes the display unit 14 to display a message asking the user whether the diagnosis is possible.

[0105] More preferably, the abnormality determination unit 11 extends the measurement time set for each of the diagnosis conditions based on the rotational speed of the object to be diagnosed.

[0106] More preferably, the diagnosis condition specifies a filter that restricts the frequency band of the detection signal of vibration. After diagnosing according to the diagnosis condition, the abnormality determination unit 11 obtains the envelope spectrum of the vibration data that has been subjected to filter processing in a frequency band different from the diagnosis condition.

[0107] More preferably, when the abnormality determination unit 11 determines that no damage characteristics are found after diagnosing according to the diagnosis condition, the abnormality determination unit 11 proposes to the user to re-measure and diagnose under conditions different from the diagnosis condition.

[0108] More preferably, in the first diagnosis, the abnormality determination unit 11 sets, as the diagnosis condition, the condition determined from the results of measurement and diagnosis under a plurality of conditions, in which the characteristics of the damage that the user particularly wants to monitor appear, for future use.

[0109] More preferably, the determination reference value includes a determination value for determining that no damage characteristics are found in the object to be diagnosed. The determination value is determined with respect to the area of the spectrum included in the range of the frequency where a peak is assumed to appear in consideration of the increase and decrease of the rotational speed in advance.

[0110] Preferably, the vibration analyzer 1 further includes a display unit 14. The abnormality determination unit 11 causes the display unit 14 to display, on a graph, the range where a primary frequency peak indicating damage to the bearing, gear, or rotating shaft is assumed to appear in the frequency spectrum or the envelope spectrum.

[0111] More preferably, as shown in FIG. 13, the abnormality determination unit 11 causes the display unit 14 to display, on a graph, the range where a frequency peak indicating damage to the bearing, gear, or rotating shaft is assumed to appear up to the second or higher order.

[0112] As shown in FIG. 15, the abnormality determination unit 11 outputs a report that can confirm the diagnosis result and the history of past measurement results in the data format of an image.

[0113] In other aspects, the present embodiment relates to a vibration analysis system. The vibration analysis system includes a measuring instrument 2 that measures the vibration of a diagnosis target, and the vibration analysis device 1 described in any of the above. The vibration analysis device 1 is realized by application software that operates on a portable information terminal.

[0114] More preferably, as shown in FIG. 1, the portable information terminal 1 and the measuring instrument 2 communicate wirelessly. As shown in FIG. 16, they may communicate by wire.

[0115] More preferably, when the shape of the measuring instrument 2 is vertically long, it has a constricted shape with a recess at the center of the housing.

[0116] According to the vibration analysis device of the present embodiment, since the settings related to the analysis are automatically selected from the information (bearing type, rotation speed) of the diagnosis target input by the user, vibration analysis with a certain accuracy can be performed regardless of the proficiency of the user.

[0117] In addition, by providing a function of repeatedly measuring under the selected diagnosis conditions, it is possible to measure even for a time longer than the set measurement time. As a result, long-time measurement at a high sampling frequency can be realized, so that early damage detection is possible even for a diagnosis target with a low rotation speed. Also, considering the data processing load and data capacity, which are the demerits of extending the measurement time, if the data length is automatically set from the rotation speed, these demerits can be minimized.

[0118] Furthermore, since the bandwidth of the frequency filter can be changed for the data measured once and the envelope spectrum can be recalculated, detailed analysis can be performed.

[0119] In addition, since it is possible to set the time from when the measurement start button of the vibration analyzer is pressed until the measurement starts, it is no longer necessary to press the button of the vibration analyzer and the start button of the device to be diagnosed at the same time, and even a single operator can perform measurement aiming at abnormal vibration.

[0120] 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 rather than the description of the above embodiments, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Explanation of Reference Numerals

[0121] 1, 1A Portable information terminal, 2, 2A Measuring instrument, 11 Abnormality determination unit, 12 Setting unit, 13 Communication unit, 14 Display unit, 15 Database unit, 16 Condition determination unit, 17 Analysis unit, 21 Microcomputer, 22 Memory, 23 Communication module, 24 Converter, 25 Anti-aliasing filter, 26 Acceleration sensor, 100 Vibration analysis system.

Claims

1. A vibration analysis device for diagnosing a machine state based on detected vibrations, comprising: a setting unit that sets a diagnosis target including a bearing, a rotational speed, and a determination reference value; a condition determination unit that determines diagnosis conditions from information on the diagnosis target; an analysis unit that performs frequency analysis on input data; an abnormality determination unit that determines abnormality of the diagnosis target based on the determination reference value; a display unit; wherein when the rotational speed set by the setting unit is a rotational speed at which no peak indicating damage to the diagnosis target appears in the envelope spectrum in a combination of the vibration frequency caused by an inner ring injury of the bearing and the diagnosis conditions, the abnormality determination unit causes the display unit to display a warning message.

2. The vibration analysis device according to claim 1, further comprising a database unit that stores parameters for specifying a damaged part of the diagnosis target, wherein the database unit stores, as the parameters, the rotational speed of the bearing, the specifications of the bearing, or coefficients of a mathematical formula, and the mathematical formula calculates the vibration frequency caused by an inner ring injury of the bearing, the vibration frequency caused by an outer ring injury of the bearing, and the vibration frequency caused by a rolling element injury of the bearing based on the rotational speed.

3. The information is the rotational speed of the diagnosis target and the inner ring damage frequency, which is the vibration frequency caused by an inner ring injury of the bearing, and the condition determination unit selects, as the diagnosis conditions, conditions corresponding to the information.

4. The vibration analysis device according to claim 3, wherein the condition determination unit selects the diagnosis conditions from a plurality of conditions in which the sampling frequency and the measurement time are adjusted so that the number of data is equal.

5. The vibration analysis device according to claim 4, wherein the abnormality determination unit extends the measurement time set for each of the diagnosis conditions based on the rotational speed of the diagnosis target.

6. The diagnosis conditions specify a filter that limits the frequency band of the vibration detection signal, and the abnormality determination unit obtains an envelope spectrum of vibration data subjected to filter processing in a frequency band different from the diagnosis conditions after diagnosis under the diagnosis conditions.

7. The vibration analysis apparatus according to claim 4, wherein when the abnormality determination unit determines that no damage characteristics are found after diagnosis based on the diagnosis condition, the abnormality determination unit proposes re-measurement and diagnosis to the user under conditions different from the diagnosis condition.

8. The vibration analysis apparatus according to claim 4, wherein in the first diagnosis, the abnormality determination unit sets, as the diagnosis condition for future use, the condition determined to have damage characteristics from the results of measurement and diagnosis under a plurality of conditions.

9. The determination reference value includes a determination value for determining that no damage characteristics are found in the diagnosis target, and the determination value is determined with respect to the area of the spectrum included in the frequency range where a peak is assumed to appear in consideration of an increase or decrease in the rotational speed in advance. The vibration analysis apparatus according to claim 7 or 8.

10. The vibration analysis apparatus according to claim 2, wherein the abnormality determination unit causes the display unit to display, on a graph, a range where a primary frequency peak indicating damage to the bearing, gear, or rotating shaft is assumed to appear in the frequency spectrum or envelope spectrum.

11. The vibration analysis apparatus according to claim 10, wherein the abnormality determination unit causes the display unit to display, on a graph, a range where a frequency peak indicating damage to the bearing, gear, or rotating shaft is assumed to appear up to the second order or higher order.

12. The vibration analysis apparatus according to claim 1, wherein the abnormality determination unit outputs a report that can confirm the diagnosis result and the history of past measurement results in the data format of an image.

13. A measuring instrument for measuring the vibration of the diagnosis target, The vibration analysis system includes the vibration analysis apparatus according to any one of claims 1 to 12, wherein the vibration analysis apparatus is realized by application software operating on a portable information terminal.

14. The vibration analysis system according to claim 13, wherein communication between the portable information terminal and the measuring instrument is performed wirelessly or by wire.

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