Anomaly detection device and anomaly detection method

Abstract

An abnormality detection device that detects an abnormality in a rotating mechanism (104), the rotating mechanism having: a rotating shaft (101); a bearing (102) that supports the free rotation of the rotating shaft (101); and a gear (103) that rotates integrally with the rotating shaft (101). The abnormality detection device compares the actual rotation variation characteristics when the rotating shaft (101) rotates at a specific rotational speed with the normal rotation variation characteristics. When the upward offset amount of the actual rotation variation characteristics relative to the normal rotation variation characteristics reaches or exceeds the bearing abnormality determination threshold, it detects an abnormality in the rotating mechanism (104) caused by burnout of the bearing (102); when the increase amount of the amplitude of the actual rotation variation characteristics relative to the normal rotation variation characteristics reaches or exceeds the gear abnormality determination threshold, it detects an abnormality in the rotating mechanism (104) caused by wear of the gear (103).

Description

Technical Field

[0001] The present disclosure relates to an abnormality detection device and an abnormality detection method for detecting an abnormality in a rotating mechanism. Background Art

[0002] In a rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft, an abnormality may occur due to burnout of the bearing or wear of the gear. For example, burnout of the bearing is likely to occur when the lubricating oil supplied to the bearing is insufficient, and wear of the gear is likely to occur corresponding to aging.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-175775 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] It is desired to detect an abnormality in a rotating mechanism caused by burnout of a bearing or wear of a gear.

[0008] An object of the present disclosure is to provide an abnormality detection device and an abnormality detection method capable of detecting an abnormality in a rotating mechanism caused by burnout of a bearing or wear of a gear.

[0009] Technical Means for Solving the Technical Problem

[0010] A first aspect of the present disclosure is an abnormality detection device that detects an abnormality in a rotating mechanism, the rotating mechanism including: a rotating shaft; a bearing that supports the rotating shaft for free rotation; and a gear that rotates integrally with the rotating shaft; the abnormality detection device compares an actual rotation variation characteristic when the rotating shaft is rotated at a specific rotational speed with a normal rotation variation characteristic, and when an upward offset amount of the actual rotation variation characteristic with respect to the normal rotation variation characteristic reaches a bearing abnormality determination threshold or more, determines that an abnormality in the rotating mechanism caused by burnout of the bearing has occurred, and thereby detects the abnormality.

[0011] A second aspect of the present disclosure is an abnormality detection device that detects an abnormality in a rotating mechanism, the rotating mechanism including: a rotating shaft; a bearing that supports the rotating shaft to rotate freely; and a gear that rotates integrally with the rotating shaft. The abnormality detection device compares the actual rotational variation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational variation characteristics, and when the increase in amplitude of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds a gear abnormality determination threshold, it determines that an abnormality in the rotating mechanism due to wear of the gear has occurred, and thus detects the abnormality.

[0012] A third aspect of the present disclosure is an abnormality detection device that detects an abnormality in a rotating mechanism, the rotating mechanism including: a rotating shaft; a bearing that supports the rotating shaft to rotate freely; and a gear that rotates integrally with the rotating shaft. The abnormality detection device compares the actual rotational variation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational variation characteristics. When the upward offset of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds a bearing abnormality determination threshold, it determines that an abnormality in the rotating mechanism due to burnout of the bearing has occurred, and thus detects the abnormality. When the increase in amplitude of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds a gear abnormality determination threshold, it determines that an abnormality in the rotating mechanism due to wear of the gear has occurred, and thus detects the abnormality.

[0013] A fourth aspect of the present disclosure is an abnormality detection method that detects an abnormality in a rotating mechanism, the rotating mechanism including: a rotating shaft; a bearing that supports the rotating shaft to rotate freely; and a gear that rotates integrally with the rotating shaft. The method includes the following steps: comparing the actual rotational variation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational variation characteristics, and when the upward offset of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds a bearing abnormality determination threshold, it determines that an abnormality in the rotating mechanism due to burnout of the bearing has occurred, and thus detects the abnormality.

[0014] A fifth aspect of the present disclosure is an abnormality detection method that detects an abnormality in a rotating mechanism, the rotating mechanism including: a rotating shaft; a bearing that supports the rotating shaft to rotate freely; and a gear that rotates integrally with the rotating shaft. The method includes the following steps: comparing the actual rotational variation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational variation characteristics, and when the increase in amplitude of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds a gear abnormality determination threshold, it determines that an abnormality in the rotating mechanism due to wear of the gear has occurred, and thus detects the abnormality.

[0015] The sixth aspect of the present disclosure is an anomaly detection method for detecting anomalies in a rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft. The method includes the following steps: comparing the actual rotational variation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational variation characteristics, and when the upward offset of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds the bearing anomaly determination threshold, it is determined that an anomaly in the rotating mechanism has occurred due to burnout of the bearing, and thus the anomaly is detected; when the increase in amplitude of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds the gear anomaly determination threshold, it is determined that an anomaly in the rotating mechanism has occurred due to wear of the gear, and thus the anomaly is detected.

[0016] The rotational variation characteristics are preferably torque versus rotation angle characteristics or rotational angular velocity versus rotation angle characteristics.

[0017] Preferably, the anomaly of the rotating mechanism is notified.

[0018] Advantages of the Invention

[0019] According to the anomaly detection device and anomaly detection method of the present disclosure, it is possible to detect anomalies in a rotating mechanism caused by burnout of a bearing or wear of a gear. Brief Description of the Drawings

[0020] Figure 1 It is a diagram illustrating an anomaly detection device.

[0021] Figure 2A It is a diagram illustrating normal rotational variation characteristics.

[0022] Figure 2B It is a diagram illustrating rotational variation characteristics in the case of bearing burnout.

[0023] Figure 2C It is a diagram illustrating rotational variation characteristics in the case of gear wear.

[0024] Figure 3 It is a diagram illustrating an anomaly detection method.

[0025] Figure 4 It is a diagram illustrating an anomaly detection method. Detailed Description of the Embodiments

[0026] [Anomaly Detection Device]

[0027] As Figure 1As shown, the abnormality detection device 100 detects an abnormality in the rotating mechanism 104, which includes: a rotating shaft 101; a bearing 102 that supports the free rotation of the rotating shaft 101; and a gear 103 that rotates integrally with the rotating shaft 101.

[0028] For example, the rotating mechanism 104 is used in an internal combustion engine. The rotating shaft 101 is an idle gear shaft, the bearing 102 is an idle gear bushing, and the gear 103 is an idle gear.

[0029] The abnormality detection device 100, for example, includes: an arithmetic component 105 that is a computer or an engine control unit. The arithmetic component 105 compares the actual rotational variation characteristics when the rotating shaft 101 rotates at a specific rotational speed with the normal rotational variation characteristics (refer to Figure 2A ). When the upward offset of the actual rotational variation characteristics relative to the normal rotational variation characteristics reaches or exceeds the bearing abnormality determination threshold, it detects an abnormality in the rotating mechanism 104 caused by the burnout of the bearing 102.

[0030] The reason for comparing the actual rotational variation characteristics when the rotating shaft 101 rotates at a specific rotational speed with the normal rotational variation characteristics is that if the rotational speed of the rotating shaft 101 changes, the rotational variation characteristics will also change, so a meaningful comparison cannot be made. Therefore, for example, it is necessary to make the comparison under stable conditions such as when the internal combustion engine is idling or running without load.

[0031] The rotational variation characteristics are the torque-rotation angle characteristics or the rotational angular velocity-rotation angle characteristics. The torque-rotation angle characteristics represent the relationship between the torque [Nm] acting on the rotating shaft 101 under so-called torque pulsation (torque waveform) and the rotation angle [deg] of the rotating shaft 101. The rotational angular velocity-rotation angle characteristics show the relationship between the rotational angular velocity [rad / s] of the rotating shaft 101 and the rotation angle [deg] of the rotating shaft 101. In addition, the torque or rotational angular velocity is positive with respect to the torque or rotational angular velocity in the desired rotation direction of the rotating shaft 101.

[0032] The torque can be detected by a torque sensor, the rotation angle can be detected by a rotation angle sensor, and the rotational angular velocity can be detected by a rotational angular velocity sensor. In addition, it is also possible to measure the rotational angular velocity by arranging a sensor capable of detecting the tooth tip at the position facing the tooth surface of the gear 103 and grasping the rotation period of each tooth. The sensor capable of detecting the tooth tip is, for example, a gap sensor.

[0033] If the bearing 102 burns out, the rotating shaft 101 becomes difficult to rotate, and the torque required to rotate the rotating shaft 101 is larger than normal at any rotation angle. Therefore, as Figure 2BAs shown, as the burnout of the bearing 102 progresses, the upward offset of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics (the amount indicating how much the torque at a predetermined rotational angle changes in the positive direction) also increases.

[0034] That is, if the bearing 102 burns out, both the maximum and minimum values of the torque increase. Additionally, since the torque is proportional to the rotational angular velocity, if the bearing 102 burns out, both the maximum and minimum values of the rotational angular velocity increase.

[0035] Therefore, experimentally measure the upward offset in the case of the burnout of the bearing 102 in advance, set the bearing abnormality determination threshold based on this upward offset, and when the upward offset reaches or exceeds the bearing abnormality determination threshold, it is sufficient to detect the abnormality of the rotating mechanism 104 caused by the burnout of the bearing 102.

[0036] In addition, when the arithmetic unit 105 of the abnormality detection device 100 compares the actual rotational fluctuation characteristics when the rotating shaft 101 rotates at a specific rotational speed with the normal rotational fluctuation characteristics, and when the amplitude increase of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the gear abnormality determination threshold, it is determined that an abnormality of the rotating mechanism 104 caused by the wear of the gear 103 has occurred, and this abnormality is detected.

[0037] If the gear 103 wears, the backlash increases, and the maximum value of the torque required to rotate the rotating shaft 101 becomes larger compared to the normal situation. Therefore, as Figure 2C shown, as the wear of the gear 103 progresses, the amplitude increase of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics also increases.

[0038] That is, if the gear 103 wears, only the maximum value of the torque increases. Additionally, since the torque is proportional to the rotational angular velocity, if the gear 103 wears, the maximum value of the rotational angular velocity also increases.

[0039] Therefore, experimentally measure the amplitude increase in the case of the wear of the gear 103 in advance, set the gear abnormality determination threshold based on this amplitude increase, and when the amplitude increase reaches or exceeds the gear abnormality determination threshold, it is sufficient to detect the abnormality of the rotating mechanism 104 caused by the wear of the gear 103.

[0040] It should be noted that, in the case of detecting any one of the abnormality of the rotating mechanism 104 caused by the burnout of the bearing 102 and the abnormality of the rotating mechanism 104 caused by the wear of the gear 103, considering the case where a deviation occurs in the rotational variation characteristics due to the operating state of the internal combustion engine or auxiliary machinery, the rotational variation characteristics can also be obtained multiple times within each predetermined cycle. Only when the rotational variation characteristics with an upward offset reaching or exceeding the bearing abnormality determination threshold exist multiple times, or the rotational variation characteristics with an amplitude increase reaching or exceeding the gear abnormality determination threshold exist multiple times, it is determined that the rotating mechanism 104 is abnormal, thereby detecting this abnormality.

[0041] That is, even if the upward offset of the rotational variation characteristics in a certain cycle reaches or exceeds the bearing abnormality determination threshold, or the amplitude increase of the rotational variation characteristics in a certain cycle reaches or exceeds the gear abnormality determination threshold, it can be considered that it accidentally reaches above each threshold due to the deviation of the rotational variation characteristics. Therefore, when the upward offset or the amplitude increase does not continuously reach above each threshold, it is determined that the rotating mechanism 104 is normal.

[0042] In addition, when the abnormality of the rotating mechanism 104 caused by the burnout of the bearing 102 and the abnormality of the rotating mechanism 104 caused by the wear of the gear 103 occur simultaneously, both the upward offset and the amplitude increase of the actual rotational variation characteristics with respect to the normal rotational variation characteristics reach or exceed the threshold.

[0043] Furthermore, it is also possible to grasp the development state of the abnormality corresponding to the degree of deviation from both by comparing the upward offset and the amplitude increase of the actual rotational variation characteristics with respect to the normal rotational variation characteristics with each threshold. That is, the larger the upward offset and the amplitude increase of the actual rotational variation characteristics with respect to the normal rotational variation characteristics are and the closer they are to each threshold, the clearer the deterioration towards abnormality and the like becomes.

[0044] Therefore, it is also possible to predict the period until the occurrence of the abnormality by observing the degree of deviation between the upward offset and the amplitude increase of the actual rotational variation characteristics with respect to the normal rotational variation characteristics and each threshold.

[0045] Furthermore, the abnormality detection device 100 has, for example: an output component 106 that is part of the function of a computer or an engine control unit. The output component 106 notifies the abnormality of the rotating mechanism 104 when detecting any one of the abnormality of the rotating mechanism 104 caused by the burnout of the bearing 102 and the abnormality of the rotating mechanism 104 caused by the wear of the gear 103.

[0046] The output component 106 notifies the operator or manager of the rotating mechanism 104 of the abnormality of the rotating mechanism 104 through, for example, wireless communication or wired communication. Specifically, for example, if the rotating mechanism 104 is a rotating mechanism of an internal combustion engine mounted on a vehicle, the output component 106 notifies the driver of the vehicle whether the abnormality of the rotating mechanism 104 is caused by the burnout of the bearing 102 or the wear of the gear 103 through an indicator light or a display, and urges the replacement of components or the storage and repair of the vehicle. In addition, the vehicle manager or repairer (a person near the vehicle or a person at a location separated from the vehicle may also be notified) can be notified in the same way. In addition to notification, the output component 106 can also output the abnormality of the rotating mechanism 104 to a management server or the like to record log data.

[0047] [Abnormality detection method]

[0048] As Figure 3 shown, the abnormality detection method M100 is a method for detecting the abnormality of the rotating mechanism 104, and the rotating mechanism 104 has: a rotating shaft 101; a bearing 102 that supports the free rotation of the rotating shaft 101; and a gear 103 that rotates integrally with the rotating shaft 101.

[0049] Specifically, in the initial step S101, the actual rotational fluctuation characteristics when the rotating shaft 101 rotates at a specific rotational speed are obtained, and then in step S102, it is determined whether the upward offset of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics is above the bearing abnormality determination threshold.

[0050] When the upward offset reaches or exceeds the bearing abnormality determination threshold, the abnormality of the rotating mechanism 104 caused by the burnout of the bearing 102 is detected, and in the subsequent step S103, the abnormality of the rotating mechanism 104 caused by the burnout of the bearing 102 is notified to the outside and output.

[0051] In addition, as Figure 4 shown, the abnormality detection method M200 is a method for detecting the abnormality of the rotating mechanism 104, and the rotating mechanism 104 has: a rotating shaft 101; a bearing 102 that supports the free rotation of the rotating shaft 101; and a gear 103 that rotates integrally with the rotating shaft 101.

[0052] Specifically, in the initial step S201, the actual rotational fluctuation characteristics when the rotating shaft 101 rotates at a specific rotational speed are obtained, and in the subsequent step S202, it is determined whether the amplitude increase of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the gear abnormality determination threshold.

[0053] When the increase amount of the amplitude reaches or exceeds the gear abnormality determination threshold, it is determined that an abnormality of the rotating mechanism 104 caused by the wear of the gear 103 has occurred, and this abnormality is detected. In the subsequent step S203, it is notified and output to the outside that an abnormality of the rotating mechanism 104 caused by the wear of the gear 103 has occurred.

[0054] As described above, by comparing the actual rotational fluctuation characteristics when the rotating shaft 101 rotates at a specific rotational speed with the normal rotational fluctuation characteristics, it is possible to distinguish the abnormality of the rotating mechanism 104 caused by the burnout of the bearing 102 and the abnormality of the rotating mechanism 104 caused by the wear of the gear 103.

[0055] This application is based on the Japanese patent application (Japanese Patent Application No. 2020-049752) filed on March 19, 2020, and its content is incorporated herein by reference.

[0056] Industrial Applicability

[0057] The abnormality detection device and abnormality detection method according to the present disclosure can be widely applied to the technology for detecting abnormalities of rotating mechanisms.

[0058] Explanation of Reference Numerals

[0059] 100 Abnormality detection device

[0060] 101 Rotating shaft

[0061] 102 Bearing

[0062] 103 Gear

[0063] 104 Rotating mechanism

[0064] 105 Arithmetic unit

[0065] 106 Output unit

Claims

1. An abnormality detection device that detects an abnormality in a rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft, wherein the abnormality detection device is characterized in that, when comparing the actual rotational fluctuation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational fluctuation characteristics, if the upward offset amount of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the bearing abnormality determination threshold, it is determined that an abnormality in the rotating mechanism caused by burning of the bearing has occurred, and thus this abnormality is detected. The rotational fluctuation characteristics are torque versus rotation angle characteristics or rotational angular velocity versus rotation angle characteristics.

2. The abnormality detection device according to claim 1, notifies the abnormality of the rotating mechanism.

3. An abnormality detection device that detects an abnormality in a rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft, wherein the abnormality detection device is characterized in that, when comparing the actual rotational fluctuation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational fluctuation characteristics, if the increase amount of the amplitude of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the gear abnormality determination threshold, it is determined that an abnormality in the rotating mechanism caused by wear of the gear has occurred, and thus this abnormality is detected. The rotational fluctuation characteristics are torque versus rotation angle characteristics or rotational angular velocity versus rotation angle characteristics.

4. The abnormality detection device according to claim 3, notifies the abnormality of the rotating mechanism.

5. An abnormality detection device that detects an abnormality in a rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft, wherein the abnormality detection device is characterized in that, when comparing the actual rotational fluctuation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational fluctuation characteristics, if the upward offset amount of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the bearing abnormality determination threshold, it is determined that an abnormality in the rotating mechanism caused by burning of the bearing has occurred, and thus this abnormality is detected; if the increase amount of the amplitude of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the gear abnormality determination threshold, it is determined that an abnormality in the rotating mechanism caused by wear of the gear has occurred, and thus this abnormality is detected. The rotational fluctuation characteristics are torque versus rotation angle characteristics or rotational angular velocity versus rotation angle characteristics.

6. The abnormality detection device according to claim 5, notifies the abnormality of the rotating mechanism.

7. An abnormality detection method that detects an abnormality in a rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft, wherein the abnormality detection method is characterized in that, When comparing the actual rotational fluctuation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational fluctuation characteristics, if the upward offset of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the bearing abnormality determination threshold, it is determined that an abnormality of the rotating mechanism caused by burnout of the bearing has occurred, and thus this abnormality is detected. The rotational fluctuation characteristics are torque versus rotation angle characteristics or rotational angular velocity versus rotation angle characteristics.

8. The abnormality detection method according to claim 7, Notify the abnormality of the rotating mechanism.

9. An abnormality detection method for detecting an abnormality of a rotating mechanism, the rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft, the abnormality detection method being characterized in that, When comparing the actual rotational fluctuation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational fluctuation characteristics, if the increase in amplitude of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the gear abnormality determination threshold, it is determined that an abnormality of the rotating mechanism caused by wear of the gear has occurred, and thus this abnormality is detected. The rotational fluctuation characteristics are torque versus rotation angle characteristics or rotational angular velocity versus rotation angle characteristics.

10. The abnormality detection method according to claim 9, Notify the abnormality of the rotating mechanism.

11. An abnormality detection method for detecting an abnormality of a rotating mechanism, the rotating mechanism having a rotating shaft, a bearing that supports the rotating shaft for free rotation, and a gear that rotates integrally with the rotating shaft, the abnormality detection method being characterized in that, When comparing the actual rotational fluctuation characteristics when the rotating shaft is rotated at a specific rotational speed with the normal rotational fluctuation characteristics, if the upward offset of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the bearing abnormality determination threshold, it is determined that an abnormality of the rotating mechanism caused by burnout of the bearing has occurred, and thus this abnormality is detected. If the increase in amplitude of the actual rotational fluctuation characteristics relative to the normal rotational fluctuation characteristics reaches or exceeds the gear abnormality determination threshold, it is determined that an abnormality of the rotating mechanism caused by wear of the gear has occurred, and thus this abnormality is detected. The rotational fluctuation characteristics are torque versus rotation angle characteristics or rotational angular velocity versus rotation angle characteristics.

12. The abnormality detection method according to claim 11, Notify the abnormality of the rotating mechanism.

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