JP7552504B2 - Bearing abnormality diagnosis device, bearing unit, bearing abnormality diagnosis method, and program - Google Patents

Description

The present invention relates to a bearing abnormality diagnosis device, a bearing unit, a bearing abnormality diagnosis method, and a program.

Conventionally, rotating parts such as bearings installed in mechanical devices such as vehicles are periodically diagnosed for abnormalities in order to detect damage or wear at an early stage and prevent the occurrence of failures of the rotating parts. This allows the mechanical devices to continue to operate normally. Major defects that can occur in bearings include indentations caused by foreign matter getting caught, peeling due to rolling fatigue, and other wear. Various methods have been disclosed as methods for diagnosing abnormalities in such bearings, and a method using frequency analysis is known as a general abnormality diagnosis method (see, for example, Patent Document 1). In such abnormality diagnosis methods, fast Fourier transform processing is used in the abnormality diagnosis process.

JP 2006-125976 A

The Fourier transform processing used in the abnormality diagnosis method such as that in Patent Document 1 places a high processing load and requires a large amount of processing resources. For example, a large amount of memory space is required when performing the processing. Therefore, in a low-performance device, it is expected that the diagnostic processing may take a long time or may be difficult to execute.

In view of the above problems, the present invention aims to realize bearing abnormality diagnosis with reduced processing load.

In order to solve the above problems, the present invention has the following configuration. That is, the present invention is a bearing abnormality diagnosis device,
An acquisition means for acquiring vibration information of a bearing;
a division means for dividing a section indicated by the vibration information into an impact section, the impact section being specified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation means for calculating vibration intensity in each of the impact section and the non-impact section;
and a diagnosis means for determining whether an abnormality has occurred in the bearing based on the difference or ratio between the vibration intensities in the impact section and the non-impact section calculated by the calculation means.

Another aspect of the present invention has the following configuration. That is, a method for diagnosing an abnormality, comprising:
an acquisition step of acquiring vibration information of a bearing;
a division step of dividing the section indicated by the vibration information into an impact section identified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation step of calculating vibration intensity in each of the impact section and the non-impact section;
and a diagnosis step of determining whether an abnormality has occurred in the bearing based on the difference or ratio of vibration intensity between the impact section and the non-impact section calculated in the calculation step.

Another aspect of the present invention has the following configuration. That is, a program, which is executed on a computer,
an acquisition step of acquiring vibration information of a bearing;
a division step of dividing the section indicated by the vibration information into an impact section identified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation step of calculating vibration intensity in each of the impact section and the non-impact section;
and a diagnosis step of determining whether an abnormality has occurred in the bearing based on the difference or ratio between the vibration intensities of the impact section and the non-impact section calculated in the calculation step.

This invention makes it possible to diagnose bearing abnormalities while reducing the processing load.

FIG. 1 is a schematic diagram showing an example of an apparatus configuration according to a first embodiment. FIG. 4 is a diagram for explaining frequencies corresponding to locations of a bearing where damage has occurred. FIG. 4 is a schematic diagram showing an example of a vibration waveform generated due to damage to a bearing. 5 is a schematic diagram for explaining impact sections and non-impact sections in a vibration waveform caused by damage to a bearing. FIG. FIG. 4 is a schematic diagram for explaining a method for setting an impact section and a non-impact section. 4 is a flowchart of an abnormality diagnosis process according to the first embodiment. FIG. 13 is a diagram showing an example of an apparatus configuration according to a second embodiment.

The following describes the embodiment of the present invention with reference to the drawings. Note that the embodiment described below is one embodiment for explaining the present invention, and is not intended to be interpreted as limiting the present invention, and not all of the configurations described in each embodiment are necessarily essential configurations for solving the problems of the present invention. In addition, in each drawing, the same components are given the same reference numbers to indicate their correspondence.

First Embodiment
A first embodiment of the present invention will be described below.

[Device configuration]
FIG. 1 is a schematic diagram showing an example of the overall configuration of the device according to the present embodiment. FIG. 1 shows a mechanical device 100 including a bearing unit 110 to which abnormality diagnosis by the bearing abnormality diagnosis method according to the present embodiment is applied, and a configuration of an abnormality diagnosis device 200 that performs bearing abnormality diagnosis. In the present embodiment, the rolling bearing 101 to be diagnosed for abnormality can be, for example, a self-aligning roller bearing, a tapered roller bearing, a cylindrical roller bearing, etc., but is not limited thereto. In addition, in FIG. 1, a configuration in which one bearing unit 110 is provided for one mechanical device 100 is shown for the sake of simplicity of explanation, but the present invention is not limited to this configuration, and multiple bearing units 110 may be provided for one mechanical device 100. In addition, the mechanical device 100 may include a portion other than the bearing unit 110, and only the configuration according to the present embodiment is shown here for the sake of simplicity of explanation. In the present embodiment, the mechanical device 100 is described using a traveling vehicle as an example, but is not limited thereto.

The bearing unit 110 rotatably supports the shaft end of the rotating shaft (not shown) of the machine device 100. The rotating shaft is supported by a housing (not shown) that covers the outside of the rotating shaft via a rolling bearing 101, which is a rotating part. The rolling bearing 101 includes an inner ring 104, which is a rotating ring that is fitted to the outside of the rotating shaft, an outer ring 102, which is a fixed ring that is fitted to the inside of the housing, a plurality of balls (rollers) that are a plurality of rolling elements 103 arranged between the inner ring 104 and the outer ring 102, and a retainer (not shown) that holds the rolling elements 103 in a rollable manner. In addition, in the rolling bearing 101, friction between the inner ring 104 and the rolling elements 103 and between the outer ring 102 and the rolling elements 103 is reduced by a predetermined lubrication method. The lubrication method is not particularly limited, but for example, grease lubrication or oil lubrication is used, and the type of lubricant is not particularly limited.

The bearing unit 110 is provided with a sensor 105 that detects vibrations generated from the rolling bearing 101 during operation of the machine 100. The sensor 105 is fixed near the outer ring of the housing by bolting, gluing, bolting and gluing, or embedding with a molding material. In the case of bolting, a rotation prevention function may be provided. In addition, when the sensor 105 is molded, waterproofing is achieved and vibration resistance against external vibration is improved, so that the reliability of the sensor 105 itself can be dramatically improved. In addition, the sensor 105 is not limited to a configuration in which it is fixed and installed at the inspection position, but may be installed at a position for detecting vibrations caused by the rolling bearing 101 during abnormality diagnosis. Therefore, the sensor 105 may be configured to be removable or movable.

The sensor 105 may be any sensor capable of detecting vibration, such as a vibration sensor, an acceleration sensor, an AE (Acoustic Emission) sensor, an ultrasonic sensor, or a shock pulse sensor, as long as it can convert the detected acceleration, speed, strain, stress, displacement, or other vibrations into an electrical signal. When mounting the sensor 105 on a noisy mechanical device 100, it is more preferable to use an insulated sensor, since it is less susceptible to noise. Furthermore, when the sensor 105 uses a vibration detection element such as a piezoelectric element, the element may be molded in plastic or the like. In addition, the mechanical device 100 of this embodiment may detect the vibrations of gears and wheels (both not shown) located around the rolling bearing 101, in addition to the rolling bearing 101, by the sensor 105. Furthermore, the sensor 105 is configured to detect the value of a variable used in the calculation formula described later in FIG. 2.

The sensor 105 may be an integrated sensor in which various sensors for detecting the state information of the bearing unit 110 are housed in a single housing, in addition to a vibration sensor for detecting vibrations generated by the mechanical equipment 100. As described above, in this embodiment, the mechanical equipment 100 is described as a traveling vehicle, and the rotation speed of the rolling bearing 101 varies depending on the traveling speed of the traveling vehicle. Therefore, a rotation speed sensor (not shown) for the traveling speed of the mechanical equipment 100 and the rotation speed of the rolling bearing 101 is also provided. The rotation speed sensor may detect the rotation speed by detecting an encoder (not shown) provided on the inner ring 104 of the rolling bearing 101, for example. The sensor 105 may be configured to perform a detection operation only at a specified timing (for example, when an abnormality is diagnosed) based on an instruction from a user of the abnormality diagnosis device 200, or may be configured to perform a detection operation at all times.

The abnormality diagnosis device 200 may be realized, for example, by an information processing device including a control device, a storage device, and an output device (not shown). The control device may be composed of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Single Processor), or a dedicated circuit. The storage device is composed of volatile and non-volatile storage media such as a HDD (Hard Disk Drive), a ROM (Read Only Memory), or a RAM (Random Access Memory), and can input and output various information in response to instructions from the control device. The output device is composed of a speaker, a light, or a display device such as a liquid crystal display, and notifies the operator in response to instructions from the control device. The method of notification by the output device is not particularly limited, but may be, for example, an auditory notification by voice or a visual notification by screen output. The output device may also be a network interface equipped with a communication function, and may perform the notification operation by transmitting data to an external device (not shown) via a network (not shown). Note that the content of the notification here is not limited to a notification when an abnormality is detected, but may also include a notification that the rolling bearing 101 is normal.

The abnormality diagnosis device 200 includes a signal acquisition unit 201, a vibration analysis unit 202, a vibration intensity calculation unit 203, an abnormality diagnosis unit 204, an information storage unit 205, an alarm processing unit 206, and a communication processing unit 207. Each part may be realized by the above-mentioned control device reading out a corresponding program from a storage device and executing it. Furthermore, various operations such as an alarm operation and a communication operation may be performed by the control device controlling an output device.

The signal acquisition unit 201 acquires the electrical signal detected by the sensor 105 as vibration information. Depending on the content of the electrical signal, the signal acquisition unit 201 may perform A/D (Analog/Digital) conversion using an AD converter (not shown) or signal amplification processing using an amplifier (not shown). The acquired vibration information is output to the information storage unit 205.

The vibration analysis unit 202 applies a predetermined filter process to the vibration information stored in the information storage unit 205. The filter process extracts a frequency band corresponding to the natural frequency of the rolling bearing 101 from the vibration information indicated by the electrical signal acquired by the sensor 105. The content of the filter process here is not particularly limited, and processing using an LPF (Low Pass Filter) that removes predetermined high-frequency components from the vibration information or an HPF (High Pass Filter) that removes predetermined low-frequency components may be performed. The vibration analysis unit 202 uses the vibration information to which the filter process has been applied to perform frequency analysis of the vibration indicated by the vibration information. More specifically, the vibration analysis unit 202 detects peaks in the vibration. Furthermore, the vibration analysis unit 202 determines impact zones and non-impact zones from the detected peaks. Details of the determination of the impact zone according to this embodiment will be described later with reference to FIG. 4 and FIG. 5.

The vibration intensity calculation unit 203 calculates the intensity of vibration in the impact section and non-impact section determined by the vibration analysis unit 202. In this embodiment, the root mean square (RMS) is used as the effective value for the vibration intensity. The abnormality diagnosis unit 204 performs abnormality diagnosis based on the RMS calculated by the vibration intensity calculation unit 203.

The information storage unit 205 receives and stores the vibration information output from the signal acquisition unit 201 as appropriate. The information storage unit 205 also provides the stored vibration information to the vibration analysis unit 202 as appropriate. The notification processing unit 206 performs notification processing based on the diagnosis result by the abnormality diagnosis unit 204. The communication processing unit 207 controls communication with the outside via a network (not shown). For example, the communication processing unit 207 transmits the diagnosis result by the abnormality diagnosis unit 204 to an external device (not shown).

[Relationship between the location of damage and the frequency of damage]
2 is a diagram for explaining the relationship between each part constituting the rolling bearing 101 and the frequency obtained when damage occurs in that part. As described above, the rolling bearing 101 is composed of the outer ring 102, the rolling elements 103, the inner ring 104, and a cage (not shown). The frequency characteristics generated differ depending on the part where the damage occurs. The frequency corresponding to each part can be derived by the calculation formula shown in FIG. 2.

The variables used in the calculation formula shown in FIG.
fr: Rotational speed of the inner (outer) ring [Hz]
fc: cage rotation speed [Hz]
fb: rolling element rotation speed [Hz]
dm: rolling element pitch circle diameter [mm]
Z: Number of rolling elements fi: fr-fc
Da: diameter of rolling element [mm]
α: Contact angle (angle between the perpendicular direction to the rotation axis and the load direction) [rad]

Note that values specific to the rolling bearing 101 (design specification data, etc.) are stored in advance in a storage device or the like, and are referenced when calculating the frequency. The fluctuation value is derived as appropriate from the detection results of the sensor 105, etc. The calculation formula shown in FIG. 2 is an example, and other calculation formulas may be used depending on the type of damage that occurs, etc.

FIG. 3 is a schematic diagram showing an example of a vibration waveform obtained when a damaged rolling bearing 101 is operated. In FIG. 3, the horizontal axis indicates time [s], and the vertical axis indicates amplitude. Here, an example is shown in which the rotation speed of the rolling bearing 101 is set to 185 [min ⁻¹ ], and it is assumed that the rolling bearing 101 is operated at about three rotations per second. As shown in FIG. 3, when the rolling bearing 101 is operated, a waveform caused by the damage appears periodically as peaks 301. Here, a waveform showing one peak per rotation (three times per second) is generated. In the case of a vibration waveform obtained when a normal rolling bearing 101 is operated, the peaks 301 as shown in FIG. 3 are suppressed, and the waveform is configured with an amplitude within a predetermined range.

[Determination of impact and non-impact sections]
In this embodiment, when performing an abnormality diagnosis, the vibration waveform is divided into an impact section and a non-impact section. The impact section according to this embodiment corresponds to the position of the amplitude peak that is assumed to occur when the rolling bearing 101 is damaged and the section around it. The non-impact section corresponds to a section other than the impact section. FIG. 4 is a schematic diagram showing an example in which an impact section and a non-impact section are divided in an example vibration waveform. FIG. 4 shows three impact sections corresponding to three peaks caused by damage and non-impact sections before and after them. Note that the waveforms shown in FIGS. 4 and 5 are similar to the waveforms shown in FIG. 3.

5 is a schematic diagram for explaining a method for determining impact and non-impact sections according to this embodiment. First, the position (time) at which a peak appears in the vibration waveform is detected. Next, the frequency of the vibration corresponding to the peak is calculated, and further, the occurrence period (seconds) of the peak is calculated from the reciprocal of the frequency. The frequency can be derived from the calculation formula shown in FIG. 2. Then, the impact section is determined by the following formula (1).
(Impact section)=(peak detection time)+(1/f)±ε (1)
1/f: Peak occurrence period [sec]
ε: Error range [seconds]
f: frequency (Zfi, Zfc, 2fb, or fc) corresponding to the part shown in FIG. 2 [seconds]

According to formula (1), the length of the impact section is 2×ε [seconds]. That is, when the position of a peak is detected, it is assumed that the peak is a vibration caused by damage that has occurred to the rolling bearing 101, and based on the periodicity of the vibration, the area around the position where the next peak is expected to occur is determined as the impact section. Note that if the peak occurs singly due to noise or the like, the next peak caused by the damage will not occur in the impact section determined based on that peak.

In the above example, the impact section and the non-impact section are determined using formula (1), but this is not limiting. For example, in formula (1), the same value ε is used as the error range before and after the position of the next peak identified from the periodicity of the peaks (the length of the impact section is 2 × ε [seconds]). Alternatively, different error ranges may be set before and after. Also, different calculation formulas may be used depending on the type of damage that may occur to the rolling bearing 101.

[Processing flow]
6 is a flowchart of the abnormality diagnosis process according to this embodiment. This process is executed by the abnormality diagnosis device 200, and may be realized, for example, by a control device (not shown) included in the abnormality diagnosis device 200 reading out from a storage device and executing a program for implementing each part shown in FIG.

In S601, the abnormality diagnosis device 200 acquires vibration information of the rolling bearing 101 acquired from the sensor 105, which is stored in the information storage unit 205. When abnormality diagnosis is performed in real time, the signal acquired from the sensor 105 may be acquired directly. The period of time for which the vibration information is acquired here may be determined based on the rotational speed of the rolling bearing 101. For example, as shown in FIG. 3, it is desirable to acquire a period during which the rolling bearing 101 rotates multiple times in order to improve the detection accuracy.

In S602, the abnormality diagnosis device 200 performs a filter process on the vibration information acquired in S601. For example, a filter process may be performed to extract a predetermined frequency band from the vibration information acquired in S601. Note that the content of the filter process and whether or not it is performed are not particularly limited, and this process may be omitted as necessary.

In S603, the abnormality diagnosis device 200 detects a peak position from the vibration information after the filter process in S602. There is no particular limitation on the method of detecting the peak position, but it may be identified by comparing with a predefined threshold value based on the amplitude during normal operation identified from the characteristics of the rolling bearing 101. Alternatively, the position at which the amplitude is maximum within a predetermined time interval may be identified as the peak position. In this case, the predetermined time interval may be determined based on the rotational speed (rotation period) of the rolling bearing 101.

In S604, the abnormality diagnosis device 200 focuses on one of the unprocessed parts of the rolling bearing 101 (hereinafter referred to as the "focused part"). As shown in FIG. 2, the frequency characteristics when damage occurs differ for each part of the rolling bearing 101. Note that in FIG. 2, four parts are assumed, so the four parts are processed in order. The order in which the parts are focused on is not particularly limited, but for example, priorities may be set for the parts and the processing may be performed in that order. The priorities here may be set, for example, in the order of parts most likely to be damaged.

In S605, the abnormality diagnosis device 200 calculates the frequency caused by the damage using a calculation formula corresponding to the area of interest, as shown in FIG. 2.

In S606, the abnormality diagnosis device 200 determines the impact section and the non-impact section using the peak position detected in S603 and the frequency calculated in S604, as described with reference to FIG. 5. Note that, since the frequency characteristics differ depending on the part where the damage occurred, as shown in FIG. 2, the impact section and the non-impact section may also vary.

In S607, the abnormality diagnosis device 200 calculates the root mean square (RMS) value of the vibration in each of the impact and non-impact sections determined in S606.

In S608, the abnormality detection device 200 calculates the RMS ratio calculated in S607. Specifically, the calculation is performed by the following formula (2).
RMS ratio=(RMS of impact section/RMS of non-impact section) (2)

In S609, the abnormality diagnosis device 200 determines whether the RMS ratio calculated in S608 is equal to or greater than a predetermined threshold. The threshold used here is predefined and stored in a storage device or the like provided in the abnormality diagnosis device 200. In this embodiment, if the RMS ratio is equal to or greater than the threshold, it is determined that an abnormality has occurred in the rolling bearing 101. If the RMS ratio is equal to or greater than the threshold (YES in S609), the abnormality diagnosis device 200 proceeds to S611. On the other hand, if the RMS ratio is less than the threshold (NO in S609), the abnormality diagnosis device 200 proceeds to S610.

In S610, the abnormality diagnosis device 200 determines whether there are any unprocessed parts. If there are any unprocessed parts (YES in S610), the abnormality diagnosis device 200 returns to S604 and repeats the process for the unprocessed parts. On the other hand, if there are no unprocessed parts (NO in S610), this process flow ends. In this case, it is determined that there is no abnormality in the rolling bearing 101.

In S611, the abnormality diagnosis device 200 uses an output device to perform an alarm operation to notify the user that an abnormality has occurred. As described above, the content of the alarm operation is not particularly limited, and the user of the abnormality diagnosis device 200 may be able to select from a number of alarm operations. Then, this processing flow ends.

In the above example, the abnormality diagnosis is performed by focusing on the multiple parts that make up the rolling bearing 101 in sequence, and an alarm is issued when it is determined that an abnormality has occurred. However, this is not limited to the configuration, and for example, it may be configured to calculate the frequency for multiple parts collectively and perform the abnormality diagnosis judgment collectively.

When reporting an abnormality, information about the part when it was determined that an abnormality occurred may also be reported. In the above example, the process of S606 determines whether an abnormality has occurred by judging the RMS ratio and a threshold value, but this is not limited to this. For example, a configuration may be adopted in which multiple threshold values are set in stages, and the level (urgency) of the abnormality is determined by comparing these with the RMS ratio. The threshold value used in the process of S609 may be different for each part.

In addition, in the above example, a warning operation is performed when it is determined that an abnormality has occurred, but this is not limited to the above. For example, in order to avoid erroneous judgments due to noise or the like and to improve detection accuracy, a warning operation may be performed assuming that an abnormality has occurred when the RMS ratio exceeds a threshold a predetermined number of times in succession.

In addition, in the above example, the flow is shown to complete the process as it is if no abnormality is detected, but the present invention is not limited to this configuration. For example, if no abnormality is detected, the configuration may be such that a notification or record is made that no abnormality was detected.

In the above example, an abnormality diagnosis is performed using the ratio of the shock section RMS to the non-shock section RMS. However, this is not limited to this, and an abnormality diagnosis may be performed using the difference between the shock section RMS and the non-shock section RMS (|shock section RMS - non-shock section RMS|).

Second Embodiment
A second embodiment of the present invention will be described below. Note that a description of configurations that overlap with the first embodiment will be omitted, and the description will focus on the differences.

[Device configuration]
FIG. 7 is a diagram showing an example of the overall configuration of the device according to this embodiment. FIG. 7 shows a schematic configuration of a bearing unit 710 including a rolling bearing 101 to which abnormality diagnosis by the bearing abnormality diagnosis method according to this embodiment is applied, and an alarm device 720 that notifies the bearing abnormality diagnosis. In FIG. 7, one machine device 700 is described as including a plurality of bearing units 710-1 to 710-n (n is an integer of 1 or more), and each of the plurality of bearing units 710 has the same configuration. In the following description, when an individual description of the bearing unit 710 is required, a subscript is added to the description. Note that all of the bearing units 710 do not necessarily have the same configuration, and some of them may have different configurations. The alarm device 720 and the plurality of bearing units 710-1 to 710-n included in the machine device 700 are connected to be able to communicate with each other via a network. The configuration of the network here is not particularly limited, and may be wired or wireless.

In the first embodiment, the abnormality diagnosis process is performed by an abnormality diagnosis device 200 that is provided separately from the bearing unit 110. In contrast, in this embodiment, the abnormality diagnosis process is performed separately on the bearing unit 710 side, and the diagnosis result is output to the notification device 720. Note that the same reference numbers are used in FIG. 7 for parts that perform the same operations as the parts in FIG. 1.

The bearing unit 710 is configured to include a rolling bearing 101, a sensor 105, and a diagnostic unit 711. In this embodiment, the configurations of the rolling bearing 101 and the sensor 105 are the same as those in the first embodiment. The diagnostic unit 711 may be configured, for example, by a microcomputer, and may include an IC chip as a processing unit and a memory as a storage area. The diagnostic unit 711 is connected to the alarm device 720 so as to be able to communicate with it. There are no particular limitations on the communication method used here, and it may be wired or wireless.

The diagnosis unit 711 includes a signal acquisition unit 201, a vibration analysis unit 202, a vibration intensity calculation unit 203, an abnormality diagnosis unit 204, an information storage unit 205, and a diagnosis result output unit 712. The diagnosis result output unit 712 outputs the result of the abnormality diagnosis by the abnormality diagnosis unit 204 to the alarm device 720.

The notification device 720 may be realized, for example, by an information processing device including a control device, a storage device, and an output device (not shown). The control device may be composed of a CPU, an MPU, a DSP, or a dedicated circuit. The storage device is composed of volatile and non-volatile storage media such as a hard disk and memory, and is capable of inputting and outputting various information in response to instructions from the control device. The output device is composed of a speaker, a light, or a display device such as a liquid crystal display, and issues notifications such as alarms to workers in response to instructions from the control device. The method of notification by the output device is not particularly limited, and may be, for example, an auditory notification by voice or a visual notification by screen output. Alternatively, the output device may be a network interface equipped with a communication function, and may issue notifications by transmitting data to an external device via a network.

The alarm device 720 includes a diagnostic result acquisition unit 721, a diagnostic result storage unit 722, an alarm processing unit 206, and a communication processing unit 207. The diagnostic result acquisition unit 721 acquires the diagnostic result of the rolling bearing 101 transmitted from the bearing unit 710 (diagnosis unit 711) at appropriate times. The diagnostic result acquisition unit 721 then outputs the acquired diagnostic result to the diagnostic result storage unit 722. The diagnostic result acquisition unit 721 may receive the diagnostic result from the bearing unit 710 via a network by the communication processing unit 207. The diagnostic result storage unit 722 stores the diagnostic result acquired from the diagnostic result acquisition unit 721 in a storage device (not shown) at appropriate times in association with the bearing unit 710 (or the rolling bearing 101). The diagnostic result storage unit 722 may also be configured to perform a counting process for an alarm operation based on a predetermined condition. The notification device 720 may also be configured to include a UI (User Interface) for receiving instructions from the user and to receive diagnostic instructions from the user via the UI. In this case, the notification device 720 issues an instruction to start diagnosis to the diagnosis unit 711 of the specified bearing unit 710 via the diagnosis result acquisition unit 721, and acquires the diagnosis result as a result. The instruction to start diagnosis here may be configured to be issued individually to each bearing unit 710.

The diagnostic process is the same as that described in the first embodiment using FIG. 6, so a detailed description will be omitted here. Note that in this embodiment, the notification operation may be performed for each bearing unit 710, or may be performed based on the contents obtained by tallying up the diagnostic results of multiple bearing units 710.

As described above, the configuration shown in this embodiment also makes it possible to detect abnormalities in rolling bearings without requiring high-load processing such as fast Fourier transform processing. Furthermore, the bearing unit only needs to transmit the diagnosis results to the alarm device, and there is no need to transmit the detection results of the sensor to the alarm device. Therefore, it is only necessary to transmit relatively light data, reducing the load on the network and making it possible to operate even when the mechanical device and the alarm device are physically separated or when the network performance is low.

<Other embodiments>
In addition, the present invention can also be realized by supplying a program or application for realizing the functions of one or more of the above-mentioned embodiments to a system or device via a network or a storage medium, etc., and having one or more processors in a computer of the system or device read and execute the program.

It may also be realized by a circuit that realizes one or more functions (for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array)).

As such, the present invention is not limited to the above-described embodiments, and the invention also contemplates combinations of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the descriptions in the specification and well-known technologies, and these are included in the scope of the protection sought.

As described above, the present specification discloses the following:
(1) an acquisition means for acquiring vibration information of a bearing;
a division means for dividing a section indicated by the vibration information into an impact section, the impact section being specified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation means for calculating vibration intensity in each of the impact section and the non-impact section;
and diagnosing means for determining occurrence of an abnormality in the bearing based on the difference or ratio of vibration intensities between the impact section and the non-impact section calculated by the calculating means.
According to this configuration, it is possible to execute a bearing abnormality diagnosis while reducing the processing load.

(2) The division means
Calculating the frequency of the peak using a formula for calculating a frequency when damage occurs to the bearing;
The abnormality diagnosis device described in (1) is characterized in that the section indicated by the vibration information is divided into the impact section and the non-impact section based on the position where the peak occurs and the period obtained from the calculated frequency.
According to this configuration, it is possible to reduce the processing load and to divide the vibration information used for performing abnormality diagnosis into an impact section and a non-impact section.

(3) A formula for calculating a frequency at the time when damage occurs is specified for each component constituting the bearing,
The dividing means is
Calculate the frequency for each part using the above formula,
The abnormality diagnosis device according to (2), characterized in that the section indicated by the vibration information is divided into the shock section and the non-shock section using the frequency of each of the components.
According to this configuration, it is possible to reduce the processing load and to divide the vibration information used for performing abnormality diagnosis into an impact section and a non-impact section.

(4) The abnormality diagnosis device according to any one of (1) to (3), wherein the dividing means determines, as the shock section, a predetermined range before and after a position identified by a period of the peak based on the position of the peak.
According to this configuration, it is possible to reduce the processing load and to divide the vibration information used for performing abnormality diagnosis into an impact section and a non-impact section.

(5) The abnormality diagnosis device according to any one of (1) to (4), wherein the vibration intensity is an RMS (Root Mean Square) value.
According to this configuration, it is possible to perform abnormality diagnosis while reducing the processing load.

(6) The abnormality diagnosis device according to any one of (1) to (5), wherein the diagnosis means determines that an abnormality has occurred in the bearing when a difference or ratio of vibration intensity between the impact section and the non-impact section is equal to or greater than a predetermined threshold value.
According to this configuration, it is possible to perform abnormality diagnosis while reducing the processing load.

(7) The abnormality diagnosis device according to any one of (1) to (6), wherein the acquisition means determines a length of a section indicated by the acquired vibration information in accordance with a rotational speed of the bearing.
With this configuration, it is possible to obtain vibration information suitable for the operation of the bearing.

(8) An abnormality diagnosis device according to any one of (1) to (7),
The bearing;
A sensor for detecting vibration information of the bearing;
A bearing unit comprising: an output device that outputs a diagnosis result obtained by the abnormality diagnosis device.
According to this configuration, it is possible to provide a bearing unit capable of performing an abnormality diagnosis with a reduced processing load.

(9) acquiring vibration information of the bearing;
a division step of dividing the section indicated by the vibration information into an impact section identified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation step of calculating vibration intensity in each of the impact section and the non-impact section;
and a diagnosis step of determining whether an abnormality has occurred in the bearing based on the difference or ratio of vibration intensity between the impact section and the non-impact section calculated in the calculation step.
According to this configuration, it is possible to execute a bearing abnormality diagnosis while reducing the processing load.

On the computer,
an acquisition step of acquiring vibration information of a bearing;
a division step of dividing the section indicated by the vibration information into an impact section identified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation step of calculating vibration intensity in each of the impact section and the non-impact section;
and a diagnosis process for determining whether an abnormality has occurred in the bearing based on the difference or ratio of vibration intensity between the impact section and the non-impact section calculated in the calculation process.
According to this configuration, it is possible to execute a bearing abnormality diagnosis while reducing the processing load.

100... Mechanical device 101... Rolling bearing 102... Outer ring 103... Rolling element (roller)
104... Inner ring 105... Sensor 110... Bearing unit 200... Abnormality diagnosis device 201... Signal acquisition unit 202... Vibration analysis unit 203... Vibration intensity calculation unit 204... Abnormality diagnosis unit 205... Information storage unit 206... Notification processing unit 207... Communications processing unit 700... Mechanical device 710... Bearing unit 711... Diagnosis unit 712... Diagnosis result output unit 720... Notification device 721... Diagnosis result acquisition unit 722... Diagnosis result storage unit

Claims (10)

An acquisition means for acquiring vibration information of a bearing;
a division means for dividing a section indicated by the vibration information into an impact section, the impact section being specified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation means for calculating vibration intensity in each of the impact section and the non-impact section;
and diagnosing means for determining occurrence of an abnormality in the bearing based on the difference or ratio of vibration intensities between the impact section and the non-impact section calculated by the calculating means. The dividing means is
Calculating the frequency of the peak using a formula for calculating a frequency when damage occurs to the bearing;
2. The abnormality diagnosis device according to claim 1, wherein the section indicated by the vibration information is divided into the shock section and the non-shock section based on the position where the peak occurs and the period obtained from the calculated frequency. A formula for calculating a frequency at which damage occurs is defined for each component constituting the bearing,
The dividing means is
Calculate the frequency for each part using the above formula,
3. The abnormality diagnosis device according to claim 2, wherein the section indicated by the vibration information is divided into the shock section and the non-shock section using the frequency of each of the components. The abnormality diagnosis device according to any one of claims 1 to 3, characterized in that the dividing means determines, as the shock section, a predetermined range before and after a position identified by the period of the peak based on the position of the peak. The abnormality diagnosis device according to any one of claims 1 to 4, characterized in that the vibration intensity is RMS (Root Mean Square). The abnormality diagnosis device according to any one of claims 1 to 5, characterized in that the diagnosis means determines that an abnormality has occurred in the bearing when the difference or ratio of vibration intensity between the impact section and the non-impact section is equal to or greater than a predetermined threshold value. The abnormality diagnosis device according to any one of claims 1 to 6, characterized in that the acquisition means determines the length of the section indicated by the acquired vibration information according to the rotational speed of the bearing. An abnormality diagnosis device according to any one of claims 1 to 7,
The bearing;
A sensor for detecting vibration information of the bearing;
A bearing unit comprising: an output device that outputs a diagnosis result obtained by the abnormality diagnosis device. an acquisition step of acquiring vibration information of a bearing;
a division step of dividing the section indicated by the vibration information into an impact section identified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation step of calculating vibration intensity in each of the impact section and the non-impact section;
and a diagnosis step of determining whether an abnormality has occurred in the bearing based on the difference or ratio of vibration intensity between the impact section and the non-impact section calculated in the calculation step. On the computer,
an acquisition step of acquiring vibration information of a bearing;
a division step of dividing the section indicated by the vibration information into an impact section identified based on a position indicating an amplitude peak and a period of the peak, and a non-impact section indicating a section different from the impact section;
a calculation step of calculating vibration intensity in each of the impact section and the non-impact section;
and a diagnosis process for determining whether an abnormality has occurred in the bearing based on the difference or ratio of vibration intensity between the impact section and the non-impact section calculated in the calculation process.

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