JP6867220B2 - Sensor unit - Google Patents

Description

The present invention relates to a sensor unit of a rotating machine.

Rotating machines are broadly divided into important machines and general-purpose machines.

An important rotating machine such as a water supply pump of a power plant uses a monitoring system for constantly monitoring the operating condition. The monitoring system reads the detected values from the vibration sensor and the temperature sensor arranged around the bearing, and outputs an abnormality alarm when the detected value exceeds a preset threshold value. This monitoring system also requires a dedicated vibrometer, data logger, personal computer, etc., which is large-scale and expensive, and requires experience and skill in handling. In addition, when an abnormal alarm is issued, it is necessary to analyze the cause of abnormal vibration by frequency analysis, etc., diagnose it, and determine countermeasures, and advanced knowledge and experience are required to deal with it.

General-purpose rotating machines are divided into monitored machines and non-supervised machines. Some general-purpose rotating machines, which cause a large loss due to failure stop, are positioned as monitored machines like important rotating machines, and may be constantly monitored by a monitoring system. However, in most cases, it is common for workers to carry out patrol monitoring using a portable measuring device in order to reduce monitoring costs. In order to eliminate this patrol monitoring, it is desired to develop an inexpensive monitoring device that can be used in general-purpose rotating machines. Further, since general-purpose rotary machines include small ones of about 0.1 kW to medium-sized ones of about 100 kW, small ones are desired as monitoring devices.

Patent Document 1 discloses a sensor unit that is installed in a bearing case of a rotating machine to monitor the soundness of a rolling bearing. The case of this sensor unit includes a case body having an opening at one end and a pedestal that closes the opening of the case body. A substrate and a battery are fixed to the case body, and a vibration sensor, an MPU (data arithmetic processor), an LED, a wireless communication chip, and the like are mounted on the substrate. Further, Patent Document 2 discloses a monitoring device in which a vibration sensor is directly fixed to a rotating machine to be monitored, and a monitoring control unit housed in a monitoring box and a vibration sensor are connected by a cable.

Further, as shown in FIG. 1, Non-Patent Document 1 describes the relationship between the time from when the detection frequency around the bearing of the rotating machine shows an upward tendency to the failure and the magnification of the detection frequency with respect to the normal value. It is disclosed. With reference to FIG. 1, it is known that in a rotating machine equipped with rolling bearings, when the predominant frequency component is 1 kHz or less, the statistical remaining life until failure stop is 1000 hours (approximately 40 days) or less. Has been done. The statistical remaining life of rolling bearings is 1000 to 3000 hours (approximately 1 to 4 months) when the dominant frequency component is 1 kHz to 10 kHz, and when the dominant frequency component is 10 kHz to 30 kHz. It is known to be 3000 to 7000 hours (generally 4 to 10 months).

U.S. Patent Application Publication No. 2014/152451 Japanese Unexamined Patent Publication No. 2016-188637

PLANT ENGINEER April 2012 issue [Magazine] "Technology and application of hybrid bearing diagnostic system (MD-370)" Takashi Sako et al.

In the sensor unit of Patent Document 1, the vibration sensor and the case body are integrated. Therefore, if the upper limit of the frequency detected by the vibration sensor is set to a value of 50% or more of the resonance frequency of the case body (2 to 3 kHz in the example of Patent Document 1), the vibration sensor detects the resonance of the case body, so that the bearing It is not possible to accurately detect only the vibration of. Therefore, in the sensor unit of Patent Document 1, the upper limit of the detection frequency is set to 1 kHz. In this case, since there is not enough time from the detection of the abnormality of the vibration value to the preparation of the replacement part, there is a possibility that the failure may stop or the loss due to the stop may occur. In addition to the wear of rolling bearings, the factors that increase the vibration of 1 kHz or less include poor centering, poor construction of the gantry, excessive piping load, excessive or underflow rate, and occurrence of cavitation. Therefore, in order to analyze whether the cause of the abnormal vibration is due to wear of the rolling bearing or other factors, a precise diagnosis by a skilled person is required, and it is difficult for those who do not.

In the monitoring device of Patent Document 2, since the vibration sensor and the monitoring control unit are fixed separately, it is possible to detect a dominant frequency component higher than 1 kHz by the vibration sensor. However, since it is necessary to connect the vibration sensor and the monitoring / control unit with a cable, the installation workability is poor. Also, the exposed cable may break for some reason.

An object of the present invention is to provide a sensor unit that can be easily attached to a monitored object and can detect a predominant frequency higher than 1 kHz.

The present invention supplies power to a sensor board on which a vibration sensor for detecting vibration of a monitored object is mounted, a main board electrically connected to the sensor board, and the sensor board and the main board. Provided is a sensor unit including a battery for the purpose, a sensor substrate, a main substrate, and a case having an opening at one end in which the battery is housed.

In this embodiment, the main substrate and the battery and is arranged integrally with the casing, respectively Tei Rutotomoni, the sensor substrate is disposed in a non-contact state with the case in the opening of the case, and the sensor substrate Each of the cases is directly fixed to the monitored object.

In this sensor unit, the vibration of the object to be monitored is directly transmitted to the vibration sensor and detected by the vibration sensor. On the other hand, cases where the main substrate and the battery is fixed, because it is located in a non-contact state with respect to the sensor substrate vibration sensor is mounted to vibrate in a different independent vibration system and the sensor substrate. Therefore, the resonance of the case is not directly transmitted to the vibration sensor.

Therefore, the upper limit of the detection frequency by the vibration sensor can be set to a numerical value according to the capability of the vibration sensor regardless of the resonance frequency of the case. Therefore, it is possible to accurately detect by the vibration sensor that the vibration component in the frequency band exceeding 1 kHz is predominant. As a result, it is possible to detect the period during which the statistical remaining life of the rolling bearing is one month or more, so that it is possible to have a sufficient margin in the time until the replacement part is prepared. Therefore, it is possible to prevent a failure stop of the monitored object and a loss due to the stop.

Further, the cause of the abnormal vibration exceeding 1 kHz is the wear of the rolling bearing or the occurrence of cavitation, and is not the poor centering, the poor construction of the gantry, the excessive piping load, and the excessive or excessive flow rate. In addition, high-frequency vibration due to cavitation is hardly detected in the vicinity of the bearing because the damping increases as the distance from the place of occurrence increases. Therefore, when the vibration sensor detects abnormal vibration exceeding 1 kHz, it can be diagnosed that the cause is the wear of the rolling bearing, and the person who makes the diagnosis does not need to be an expert.

Further, since the sensor unit integrally includes the sensor board on which the vibration sensor is mounted, the main board, and the battery, the mounting workability, durability, and reliability of the monitored object are high. Moreover, since there is no cable that is exposed to the outside, it is possible to eliminate the possibility of problems and ignition due to disconnection. Therefore, it is possible to provide an inexpensive and small monitoring device that can be adopted for a small general-purpose rotating machine.

The main board and the battery are fixed to the case via an insulating resin filled in the case, respectively, and the sensor board is placed in a gap portion in the case not filled with the insulating resin. Have been placed. According to this aspect, it is possible to surely suppress the resonance of the main body from being transmitted to the vibration sensor. In addition, the main board and the battery can be securely fixed in the case while being shielded from moisture and gas.

Further, on the main board, a determination unit for determining the presence or absence of an abnormality in the monitored object based on the detection value of the vibration sensor and a transmission unit for wirelessly transmitting the result of the determination unit are mounted. There is. According to this aspect, since the abnormality of the monitored object can be monitored at a monitoring center or the like other than the airport where the monitored object is installed, the convenience can be enhanced.

In the present invention, only the vibration of the monitored object can be accurately detected by the vibration sensor without being affected by the resonance frequency of the case. Therefore, it is possible to accurately detect by the vibration sensor that the vibration component in the frequency band exceeding 1 kHz is predominant. As a result, it is possible to prevent a failure stop of the monitored object and a loss due to the stop, and it is possible to diagnose the cause of abnormal vibration even if the person is not an expert. Further, since each component is integrally provided in the case, it is possible to improve the workability of attaching to the monitored object and avoid problems due to the disconnection of the cable.

A graph showing the relationship between the time from when the detection frequency shows an upward tendency to failure and the magnification of the detection frequency with respect to the normal value. The front sectional view which shows the outline of the sensor unit which concerns on 1st Embodiment. A side sectional view of FIG. 2A. The block diagram which shows the structure of a sensor unit. The front sectional view which shows the outline of the sensor unit which concerns on 2nd Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 3rd Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 4th Embodiment. A side sectional view of FIG. 6A. A graph showing the relationship between vibration applied to the pedestal and distance. The front sectional view which shows the outline of the sensor unit which concerns on 5th Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 6th Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 7th Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 8th Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 9th Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 10th Embodiment. The front sectional view which shows the outline of the sensor unit which concerns on 11th Embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings.

(First Embodiment)
2A to 3 show the sensor unit 10 according to the first embodiment. The sensor unit 10 is attached to a monitored object (for example, a drainage pump which is a general-purpose rotating machine), and detects wear of a rolling bearing which is a replacement part of the monitored object. As shown in FIGS. 2A and 2B, the sensor unit 10 includes a sensor substrate 20, a main substrate 25, and a battery 32 in a resin case 12.

The case 12 has a rectangular parallelepiped shape including a square tubular outer peripheral wall 13 in a plan view and an end wall 14 that closes one end (upper end in FIG. 2A) of the outer peripheral wall 13. The end of the outer peripheral wall 13 on the opposite side of the end wall 14 is an opening 15. The case 12 has a compact size of 40 mm × 23 mm × 40 mm in width × depth × height. The end wall 14 is provided with a display unit 16 made of a transparent resin having translucency. The case 12 is made of an opaque resin except for the display portion 16, and is integrally molded by two-color molding. A plurality of bracket portions 17 (two in this example) for fixing to the bearing case 1 of the object to be monitored by bolts 36 are provided on the edge of the outer peripheral wall 13 on the opening 15 side.

The sensor substrate 20 is directly fixed to the bearing case 1 by one bolt 37 so as to be located in the opening 15 of the case 12. The fixed position of the bolt 37 with respect to the sensor board 20 is the center of gravity (center) of the sensor board 20. The projected area of the sensor substrate 20 as seen from the opening 15 is smaller than the area of the opening 15 so that the sensor substrate 20 does not come into contact with the case 12. A temperature sensor 21 and a vibration sensor 22 are mounted on the sensor board 20. Among them, as the vibration sensor 22, an eddy current type displacement sensor, a conductive type vibration speed sensor, a piezoelectric type vibration acceleration sensor and the like can be used. Here, a piezoelectric vibration acceleration sensor is used so that vibration of 0.01 kHz to 10 kHz can be measured. The sensor board 20 is directly fixed to the bearing case 1, and the vibration sensor 22 is mounted on the sensor board 20. Therefore, the vibration sensor 22 can directly detect the vibration of the monitored object.

The main board 25 is electrically connected to the sensor board 20 by a lead wire 26 having water resistance and weather resistance. The lead wire 26 is capable of supplying power for driving the temperature sensor 21 and the vibration sensor 22 and communicating a signal corresponding to a value detected by the temperature sensor 21 and the vibration sensor 22. With reference to FIG. 3, two LEDs (Light Emitting Diodes) 27A and 27B, a wireless communication chip 28, a processor (Micro Processor Unit) 29, and a memory 30 are mounted on the main board 25.

LED27A is blue and LED27B is red. These are display means arranged inside the display unit 16, and the irradiated light can be visually recognized from the outside of the display unit 16. The wireless communication chip 28 is a wireless communication means for transmitting and receiving information to and from a monitoring center or the like other than the airport where the object to be monitored is installed. The processor 29 is an arithmetic processing means, and is a determination unit that determines whether or not there is an abnormality in the rolling bearing by processing signals from the temperature sensor 21 and the vibration sensor 22 and diagnosing the temperature state and the vibration state of the bearing case 1. Combines functions. The memory 30 is a storage means in which a program for operating the processor 29 and a threshold value and the like used in the program are stored.

For example, if the vibration sensor 22 does not detect vibration of 0.01 kHz to 10 kHz, the processor 29 determines that it is normal and turns on the blue LED 27A. When the vibration sensor 22 detects a vibration higher than 1 kHz and 10 kHz or less, it is determined that it is time for maintenance and the red LED 27B is turned on. When the vibration sensor 22 detects vibration of 0.01 kHz or more and 1 kHz or less, it is determined that the vibration is abnormal and the red LED 27B is blinked. Further, the processor 29 transmits the determination result to the monitoring center or the like by the wireless communication chip 28.

The battery 32 supplies electric power to the sensor substrate 20 and the main substrate 25, and a lithium battery is used here. The battery 32 is connected to the main board 25 so as to be able to supply electric power by being mounted on a battery holder (not shown) mounted on the main board 25, for example. The power supply to the sensor board 20 is performed from the main board 25 via the lead wire 26.

When manufacturing the sensor unit 10, for example, LEDs 27A and 27B, a wireless communication chip 28, a processor 29, a memory 30, and the like are mounted on a main board 25 on which an electric circuit is printed, and a lead wire 26 is connected. Further, after arranging the battery 32 on the main board 25, the main board 25 is positioned on the end wall 14 side of the case 12 so that the LEDs 27A and 27B are located inside the display unit 16. Then, the tip of the lead wire 26 is pulled out to the opening 15 side and held, and then the case 12 is filled with a molten insulating resin 34 such as epoxy to integrate the main substrate 25 and the battery 32 with the case 12. As a result, the main substrate 25 and the battery 32 are shielded from moisture and gas by the insulating resin 34, and are fixed in the case 12. A gap 35 not filled with the insulating resin 34 is formed on the opening 15 side of the case 12. The gap 35 has a volume at which the sensor substrate 20 including the vibration sensor 22 does not come into contact with the insulating resin 34.

After the insulating resin 34 is cured, the sensor substrate 20 on which the temperature sensor 21 and the vibration sensor 22 are mounted is arranged in the opening 15 of the case 12, and the lead wire 26 is connected to the sensor substrate 20. As a result, the sensor unit 10 in which the sensor board 20, the main board 25, and the battery 32 are integrated is manufactured. The lead wire 26 may be connected to the sensor substrate 20 after the sensor substrate 20 is fixed to the bearing case 1 when the sensor unit 10 is attached to a monitoring object described later.

When using the sensor unit 10, first, the sensor substrate 20 is placed on the bearing case 1 of the object to be monitored and fixed by the bolts 37. After that, the case 12 is put on the sensor substrate 20 so that the outer peripheral wall 13 (insulating resin 34) does not come into contact with the sensor substrate 20, and the case 12 is fixed to the bearing case 1 by the bolt 36. Since the sensor unit 10 is formed in a compact size as described above, it can be installed in a stable state even in a limited installation space. Further, since the main substrate 25 fixed to the case 12 is located away from the bearing case 1 and covered with the insulating resin 34, it is possible to suppress an adverse effect due to the heat of the bearing.

In this way, in the sensor unit 10, the sensor substrate 20 on which the vibration sensor 22 is mounted is directly fixed to the bearing case 1. Further, other parts are housed in the case 12, and the case 12 is fixed to the bearing case 1 so as not to come into contact with the sensor substrate 20. Therefore, the vibration of the monitored object is directly transmitted to the vibration sensor 22 and detected by the vibration sensor 22. Further, the case 12 to which the main board 25 and the battery 32 are fixed vibrates in an independent vibration system different from the sensor board 20. Therefore, the resonance of the case 12 is transmitted to the vibration sensor 22, and the detection of the vibration sensor 22 is not adversely affected.

Therefore, the upper limit value of the detection frequency by the vibration sensor 22 can be set to a numerical value according to the ability of the vibration sensor 22 regardless of the resonance frequency of the case 12. Therefore, the vibration sensor 22 can accurately detect that the vibration component in the frequency band exceeding 1 kHz is predominant. Then, when the vibration frequency component of 1 kHz to 10 kHz reaches a preset abnormal level, the processor 29 turns off the blue LED 27A and turns on the red LED 27B, and transmits the red LED 27B to the monitoring center by the wireless communication chip 28. As a result, the workers at the machine station where the monitored object is installed and the workers at the monitoring center other than the machine station can diagnose that the rolling bearing of the monitored object is approaching the maintenance time.

As described above, in the sensor unit 10 of the present embodiment, since it is possible to detect the time when the statistical remaining life of the rolling bearing reaches about one month, it is necessary to allow sufficient time until the replacement parts are prepared. Can be done. Therefore, it is possible to prevent a failure stop of the monitored object and a loss due to the stop. Further, since the determination result of the processor 29 can be wirelessly transmitted to the outside by the wireless communication chip 28, the convenience regarding abnormality monitoring of the monitored object can be enhanced.

Further, in a rotating machine such as a pump, the cause of vibration exceeding 1 kHz is wear of rolling bearings or occurrence of cavitation, and in the case of poor centering, poor gantry construction, excessive piping load, and excessive or excessive flow rate. Absent. In addition, high-frequency vibration due to cavitation is hardly detected in the vicinity of the bearing because the damping increases as the distance from the place of occurrence increases. Therefore, when the vibration sensor 22 detects abnormal vibration exceeding 1 kHz, it can be diagnosed that the cause is wear of the rolling bearing, and the person who makes the diagnosis does not have to be an expert.

Further, since the sensor unit 10 integrally includes the sensor board 20 on which the vibration sensor 22 is mounted, the main board 25, and the battery 32, the mounting workability, durability, and reliability of the monitored object are high. Moreover, since there is no cable that is exposed to the outside, it is possible to eliminate the possibility of problems and ignition due to disconnection. Therefore, it is possible to realize an inexpensive and compact monitoring device that can be adopted for a small general-purpose rotating machine.

According to the sensor unit 10 of the present embodiment, it is possible to detect vibration exceeding 10 kHz by the vibration sensor 22. However, the statistical remaining life of rolling bearings at the time of such initial wear is approximately 4 months or more, and it is not economical to perform maintenance such as parts replacement at this time. Therefore, by setting the vibration frequency band of 1 kHz to 10 kHz as the threshold value, it is possible to notify one month before the failure stop, which is ideal as the alarm timing.

As described above, the sensor unit 10 integrally includes all the components and functions necessary for monitoring the vibration of the monitored object, detecting the abnormality, and outputting the alarm in the small case 12. An abnormality alarm is output when the remaining life of about a month remains. Therefore, it is possible to realize an inexpensive and compact sensor unit 10 that can secure replacement parts without causing a failure stop.

(Second Embodiment)
FIG. 4 shows the sensor unit 10 of the second embodiment. In this second embodiment, the sensor substrate 20 is fixed to the bearing case 1 by the adhesive layer 38 made of an adhesive. The configuration of the sensor substrate 20 other than the fixing method is the same as that of the first embodiment. The adhesive layer 38 is provided on the entire surface of the sensor substrate 20 opposite to the mounting surface (upper surface in FIG. 4) of the sensors 21 and 22. As the adhesive constituting the adhesive layer 38, for example, an epoxy-based adhesive having a high elastic modulus (elastic modulus: about 2000 MPa) or a cyanoacrylate-based adhesive (elastic modulus: about 1000 MPa) is preferably used. In the second embodiment as described above, the same actions and effects as those in the first embodiment can be obtained.

(Third Embodiment)
FIG. 5 shows the sensor unit 10 of the third embodiment. In this third embodiment, the sensor substrate 20 is fixed to the bearing case 1 by the permanent magnet 40. The configuration of the sensor substrate 20 other than the fixing method is the same as that of the first embodiment. The permanent magnet 40 is fixed to the surface of the sensor substrate 20 opposite to the mounting surface of the sensors 21 and 22 by the adhesive layer 38. The sensor substrate 20, the temperature sensor 21, and the vibration sensor 22 are made of a material that is not affected by the magnetic force of the permanent magnet 40. In the third embodiment as described above, the same actions and effects as those in the first embodiment can be obtained.

In the sensor units 10 of the first to third embodiments, since the case 12 and the sensor substrate 20 are directly fixed to the bearing case 1, a newly installed rotary machine is effective as a monitoring object. This is because it is necessary to form a shaft hole for tightening the bolt 36 in the bearing case 1. The sensor units 10 of the fourth to seventh embodiments described below can be easily attached to an existing rotating machine without any processing, and can detect a predominant frequency higher than 1 kHz. Is.

(Fourth Embodiment)
6A and 6B show the sensor unit 10 of the fourth embodiment. In the fourth embodiment, the sensor substrate 20, the main substrate 25, and the battery 32 similar to those in the first embodiment are integrally housed in the case 45 including the main body 46 and the pedestal 47. The sensor board 20 is fixed to the pedestal 47, the main board 25 and the battery 32 are fixed to the main body 46, and the main body 46 is fixed to the pedestal 47 so as not to come into contact with the sensor board 20.

The main body 46 is the same as the case 12 of FIG. 2A, and includes an outer peripheral wall 13, an end wall 14, an opening 15, a display portion 16, and a bracket portion 17. The opening 15 of the main body 46 is an opening area that does not come into contact with the sensor substrate 20. The inside of the main body 46 is filled with an insulating resin 34 as in the first embodiment, and the main substrate 25 and the battery 32 are fixed by the insulating resin 34. Further, a gap 35 not filled with the insulating resin 34 is formed on the opening 15 side of the main body 46.

The pedestal 47 is made of metal such as stainless steel or cast iron, and is a plate-shaped member that closes the opening 15 of the main body 46. The main body 46 and the pedestal 47 are sealed to prevent water from entering from the outside to the inside. In the present embodiment, the fixing surface 48 of the main body 46 and the sensor substrate 20 is a flat surface, and the mounting surface 49 attached to the bearing case 1 is a curved surface having a predetermined curvature. However, the mounting surface 49 of the pedestal 47 may also be a flat surface.

The pedestal 47 is provided with a first shaft hole 50 as a first fixing portion for fixing the main body 46 by a bolt 36. Further, the pedestal 47 is provided with a second shaft hole 51 as a second fixing portion for fixing the sensor substrate 20 with the bolt 37. The sensor substrate 20 fixed to the pedestal 47 by the bolt 37 is housed in the gap 35 in a non-contact state.

When manufacturing the sensor unit 10 of the fourth embodiment, the main board 25 on which the battery 32 is arranged is positioned in the main body 46 as in the first embodiment. Then, the tip of the lead wire 26 is pulled out to the opening 15 side and held, and then the main body 46 is filled with the molten insulating resin 34 to integrate the main substrate 25 and the battery 32 with the main body 46. Further, a gap 35 not filled with the insulating resin 34 is left on the opening 15 side of the main body 46.

Further, the sensor board 20 on which the temperature sensor 21 and the vibration sensor 22 are mounted is arranged on the pedestal 47, and these are fixed by bolts 37. Next, the main body 46 on which the insulating resin 34 is cured is arranged on the pedestal 47, and the lead wire 26 is connected to the sensor substrate 20. After that, the main body 46 is put on the sensor board 20 so that the outer peripheral wall 13 (insulating resin 34) does not come into contact with the sensor board 20, and the main body 46 and the pedestal 47 are fixed by the bolts 36. As a result, the sensor unit 10 that integrally houses the sensor substrate 20, the main substrate 25, and the battery 32 is manufactured.

When the sensor unit 10 is used, the sensor unit 10 is placed on the bearing case 1 of the object to be monitored, and the mounting surface 49 of the pedestal 47 is fixed with an adhesive. At this time, the adhesive is applied so that the adhesive layer 53 is formed on the entire surface of the mounting surface 49. As the adhesive, an epoxy-based adhesive having a high elastic modulus (elastic modulus: about 2000 MPa) or a cyanoacrylate-based adhesive (elastic modulus: about 1000 MPa) is used as in the second embodiment. Further, it is preferable that the adhesive layer 53 is formed in advance on the mounting surface 49 and is prevented from being adhered to other members by a release paper.

In the sensor unit 10, the sensor substrate 20 and the main body 46 are fixed to a pedestal 47 that is firmly fixed to the bearing case 1 by an adhesive layer 53 having a high elastic modulus. Therefore, the pedestal 47 and the bearing case 1 vibrate integrally, and it is possible to suppress the resonance of the main body 47 from being transmitted to the vibration sensor 22. That is, when the elastic modulus of the adhesive layer 53 is low, the pedestal 47 and the bearing case 1 do not vibrate integrally, so that the resonance of the main body 47 is transmitted to the sensor substrate 20 via the pedestal 47, which affects the detection by the vibration sensor 22. To exert. Therefore, by setting the elastic modulus of the adhesive layer 53 to 500 MPa or more, preferably 1000 MPa or more, the same operation and effect as in the first embodiment in which the sensor substrate 20 is directly fixed to the bearing case 1 can be obtained.

In this way, the upper limit of the frequency detected by the vibration sensor 22 can be set to a value according to the capability of the vibration sensor 22 regardless of the resonance frequency of the main body 46, so that the vibration component in the frequency band exceeding 1 kHz is outstanding. This can be accurately detected by the vibration sensor 22. As a result, the same actions and effects as those of the first embodiment can be obtained. Moreover, in the fourth embodiment, all the components are housed and fixed in the case 45. Therefore, the handleability can be further improved and the mounting workability to the bearing case 1 can be further improved as compared with the first embodiment. Further, since the bearing case 1 does not require any processing, it is suitable for use in an existing rotary machine.

Further, in the fourth embodiment, it is conceivable that the resonance of the main body 46 is transmitted to the pedestal 47 and the vibration is transmitted to the vibration sensor 22 when there is a problem in adhesion. In order to reliably prevent the influence of the vibration sensor 22 due to this resonance, the central axis A1 of the first shaft hole 50 and the central axis A2 of the second shaft hole 51 are provided at a predetermined interval L to attenuate the vibration. ing.

FIG. 7 shows the relationship between the magnitude (dB) of high-frequency vibration and the distance (mm). As shown in FIG. 7, the high-frequency vibration transmitted to the pedestal 47 due to the resonance of the main body 46 is attenuated as the distance increases (away from the outer peripheral wall 13). Further, the thickness T (average value) in the direction intersecting (orthogonal) with the fixed surface 48 of the pedestal 47 is also related to the transmission (damping) of the vibration. Therefore, by appropriately setting the distance L between the first shaft hole 50 and the second shaft hole 51 and the thickness T of the pedestal 47, the vibration transmitted from the main body 46 to the pedestal 47 is not transmitted to the sensor substrate 20. It is possible to prevent erroneous detection of the vibration sensor 22 due to resonance.

For example, when the thickness T of the pedestal 47 is 6 to 8 mm, by setting the interval L to 24 to 32 mm, high-frequency vibration is attenuated to the extent that the measurement accuracy of the vibration sensor 22 is not affected (about 10% of the full scale). it can. The thickness T of the pedestal 47 is preferably 3 mm or more and 10 mm or less, more preferably 5 mm or more and 8 mm or less, considering the fixing strength of the main body 46 including the main substrate 25 and the battery 32 and the total weight including the pedestal 47. Is set to. Therefore, the distance L between the first shaft hole 50 and the second shaft hole 51 is preferably formed so as to satisfy the following formula (1), and more preferably formed so as to satisfy the following formula (2).

In the fourth embodiment as described above, since the fixed portion of the main body 46 with respect to the pedestal 47 and the fixed portion of the sensor substrate 20 are spaced apart from each other, even if the resonance of the main body 46 is transmitted to the pedestal 47, The high-frequency vibration transmitted to the pedestal 47 is not transmitted to the vibration sensor 22. Therefore, the same actions and effects as those of the first embodiment can be surely obtained.

(Fifth Embodiment)
FIG. 8 shows the sensor unit 10 of the fifth embodiment. In this fifth embodiment, the sensor substrate 20 is fixed to the pedestal 47 by an adhesive layer 38 made of an adhesive. The configuration of the sensor substrate 20 other than the fixing method is the same as that of the fourth embodiment. The adhesive layer 38 is provided on the entire surface of the sensor substrate 20 opposite to the mounting surface of the sensors 21 and 22. As in the fourth embodiment, it is preferable that the first fixing portion (first shaft hole 50 ) of the main body 46 and the sensor substrate 20 with respect to the pedestal 47 have a predetermined interval L in which vibration due to resonance is attenuated. Then, in the fifth embodiment as described above, the same actions and effects as those in the fourth embodiment can be obtained.

(Sixth Embodiment)
FIG. 9 shows the sensor unit 10 of the sixth embodiment. In the sixth embodiment, the permanent magnet 40 is fixed to the sensor substrate 20, and the pedestal 47 is formed of a metal material to which the permanent magnet 40 can be attracted. The configuration of the sensor substrate 20 other than the fixing method is the same as that of the fourth embodiment. The permanent magnet 40 is fixed to the surface of the sensor substrate 20 opposite to the mounting surface of the sensors 21 and 22 by the adhesive layer 38. The sensor substrate 20, the temperature sensor 21, and the vibration sensor 22 are made of a material that is not affected by the magnetic force of the permanent magnet 40. Also in the sixth embodiment, as in the fourth embodiment, the first fixed portion ( first shaft hole 50 ) of the main body 46 with respect to the pedestal 47 and the sensor substrate 20 have a predetermined distance L at which vibration due to resonance is attenuated. It is preferable to open. Then, in the fifth embodiment as described above, the same actions and effects as those in the fourth embodiment can be obtained.

(7th Embodiment)
FIG. 10 shows the sensor unit 10 of the seventh embodiment. In the seventh embodiment, the sensor substrate 20 is fixed to the pedestal 47 via a tubular cushioning member 56. The configuration of the sensor substrate 20 other than the fixing method is the same as that of the fourth embodiment.

The pedestal 47 is provided with a through hole 55 penetrating from the inside (void portion 35) of the case 45 to the outside. A step portion 55a for arranging the cushioning member 56 is provided above the through hole 55. The cushioning member 56 is made of elastically expandable and contractible rubber, and is provided with a holding hole 57 for penetrating and holding the permanent magnet 40 fixed to the sensor substrate 20. On the inner surface of the holding hole 57, convex portions that bulge in the radial direction at intervals in the axial direction are formed.

A permanent magnet 40 is fixed to the sensor substrate 20 by an adhesive layer 38 on a surface opposite to the mounting surface of the sensors 21 and 22. The sensor substrate 20, the temperature sensor 21, and the vibration sensor 22 are made of a material that is not affected by the magnetic force of the permanent magnet 40. The permanent magnet 40 has a shape that allows it to be inserted into the holding hole 57 of the cushioning member 56. The sensor substrate 20 is in contact with only the cushioning member 56 without being in contact with the pedestal 47. The distance from the outer peripheral wall 13 of the main body 46 to the center line of the holding hole 57 is preferably formed in the same manner as in the fourth embodiment.

When manufacturing the sensor unit 10, the sensor substrate 20 is fixed to the pedestal 47 by inserting the permanent magnet 40 into the cushioning member 56 arranged in the through hole 55 of the pedestal 47. Other steps are the same as those in the fourth embodiment.

When this sensor unit 10 is used, the sensor unit 10 is placed on the bearing case 1 of the object to be monitored, and the mounting surface 49 of the pedestal 47 is fixed with an adhesive. At this time, the adhesive is applied so that the adhesive layer 53 is formed on the entire surface of the mounting surface 49 excluding the through hole 55. As a result, the permanent magnet 40 exposed from the through hole 55 is attracted to the bearing case 1.

In the sensor unit 10, the sensor substrate 20 is held by the pedestal 47 via the cushioning member 56, and the sensor substrate 20 is directly fixed to the bearing case 1 via the permanent magnet 40. Therefore, the handleability and mounting workability of the sensor unit 10 are as simple as in the fourth embodiment, and the vibration of the bearing case 1 is directly transmitted to the sensor substrate 20 as in the first embodiment. Further, even if the resonance of the main body 46 is transmitted to the pedestal 47, the vibration is damped by the cushioning member 56 and is not transmitted to the vibration sensor 22.

Therefore, since the upper limit of the frequency detected by the vibration sensor 22 can be set to a value according to the capability of the vibration sensor 22 regardless of the resonance frequency of the main body 46, the vibration component in the frequency band exceeding 1 kHz is predominant. It can be detected accurately by the sensor 22. As a result, the same actions and effects as those of the first embodiment can be obtained. Moreover, with respect to handleability and mountability, the same work and effects as those in the fourth embodiment can be obtained.

(Other embodiments)
11 to 14 show the sensor units 10 of the eighth to eleventh embodiments. In these sensor units 10, the holder 60 is fixed in the main body 46 of the case 45, and by arranging the main board 25 and the battery 32 in the holder 60, these are integrated into the main body 46. By using the holder 60 instead of the insulating resin shown in the first to seventh embodiments, the replacement work of the battery 32 and the like can be easily performed. The outer peripheral wall 13 of the main body 46 is provided with an opening (not shown) that can be opened and closed by a cover (not shown).

Further, in the eighth to eleventh embodiments, the recess 47a for arranging the sensor substrate 20 is formed on the pedestal 47. The pedestal 47 and the sensor substrate 20 may be fixed by using bolts 37 as in the first embodiment, or by using an adhesive (adhesive layer 38) as in the second embodiment, or in the third embodiment. The magnet 40 may be used as in the form.

Further, the opening 15 of the main body 46 has a shape smaller than the cross-sectional shape of the outer peripheral wall 13, and is formed at an unbalanced position of the outer peripheral wall 13 in a plan view. That is, the axes of the opening 15 are located at intervals with respect to the axes of the outer peripheral wall 13. The pedestal 47 is integrated with the outside of the opening 15 of the main body 46 by insert molding. As a result, the main substrate 25 and the battery 32 in the main body 46 can be shielded from moisture and gas. Further, the pedestal 47 projects from the main body 46 toward the bearing case 1, and a gap S is formed between the main body 46 and the bearing case 1. Therefore, the case 45 is fixed to the bearing case 1 in a cantilever structure. The method of fixing the case 45 to the bearing case 1 will be specifically described below.

In the eighth embodiment of FIG. 11, an epoxy-based (elastic modulus: about 2000 MPa) or cyanoacrylate-based (elastic modulus: about 1000 MPa) adhesive having a high elastic modulus is used, and the pedestal 47 is attached to the bearing case 1 by the adhesive layer 53. Is fixed.

In the ninth embodiment of FIG. 12, the pedestal 47 is fixed to the bearing case 1 by the permanent magnet 62. The pedestal 47 is formed with a recess 63 for arranging the permanent magnet 62. The depth of the recess 63 is set to be smaller than the thickness of the permanent magnet 62 so that a part of the permanent magnet 62 protrudes.

In the tenth embodiment of FIG. 13, the pedestal 47 is fixed to the bearing case 1 by the bolt 36. The pedestal 47 is provided with a bracket portion 65 that projects outward from the outer peripheral wall 13 of the main body 46.

In the eleventh embodiment of FIG. 14, a pedestal 67 different from the pedestal 47 is used in order to avoid forming a shaft hole in the bearing case 1. The pedestal 47 is fixed to the pedestal 67 by bolts 36 as in the tenth embodiment. The pedestal 67 is fixed to the bearing case 1 by an adhesive layer 53 with an adhesive, as in the eighth embodiment.

As in these embodiments, the method of fixing the sensor unit 10 to the bearing case 1 can be changed as needed. Further, in the eighth to eleventh embodiments described above, the same actions and effects as those of the fourth embodiment can be obtained.

The present invention is not limited to the configuration described in the above embodiment, and various modifications can be made.

For example, in the second embodiment and the third embodiment, the case 12 may be fixed to the bearing case 1 with an adhesive instead of the bolt 36. Further, in the fifth embodiment and the sixth embodiment, the main body 46 may be fixed to the pedestal 47 with an adhesive instead of the bolt 36. Further, the sensor unit 10 may adopt an explosion-proof structure depending on the place where it is installed (for example, a nuclear power plant or the like).

1 ... Bearing case (object to be monitored)
10 ... Sensor unit 12 ... Case 13 ... Outer wall 14 ... End wall 15 ... Opening 16 ... Display 17 ... Bracket 20 ... Sensor board 21 ... Temperature sensor 22 ... Vibration sensor 25 ... Main board 26 ... Lead wires 27A, 27B ... LED
28 ... Wireless communication chip 29 ... Processor 30 ... Memory 32 ... Battery 34 ... Insulating resin 35 ... Void 36 ... Bolt 37 ... Bolt 38 ... Adhesive layer 40 ... Permanent magnet 45 ... Case 46 ... Main body 47 ... Pedestal 47a ... Recess 48 ... Fixed surface 49 ... Mounting surface 50 ... First shaft hole 51 ... Second shaft hole 53 ... Adhesive layer 55 ... Through hole 55a ... Step 56 ... Cushioning member 57 ... Holding hole 60 ... Holder 62 ... Permanent magnet 63 ... Recess 65 ... Bracket part 67 ... Pedestal

Claims (3)

A sensor board on which a vibration sensor for detecting vibration of the monitored object is mounted, and
The main board electrically connected to the sensor board and
A battery for supplying electric power to the sensor board and the main board,
With the sensor board, the main board, and the case with one end opening in which the battery is housed.
With
The main board and the battery and is arranged integrally with the casing, respectively Tei Rutotomoni, the sensor substrate is disposed in a non-contact state with the case in the opening of the case,
A sensor unit in which the sensor board and the case are each directly fixed to the monitored object. The main substrate and the battery are fixed to the case via an insulating resin filled in the case, respectively.
The sensor unit according to claim 1, wherein the sensor substrate is arranged in a gap portion in the case that is not filled with the insulating resin. On the main board, a determination unit for determining the presence or absence of an abnormality in the monitored object based on the detection value of the vibration sensor, and a transmission unit for wirelessly transmitting the result of the determination unit are mounted. The sensor unit according to claim 1 or 2.

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