JP5409878B2 - Bearing condition diagnosis device - Google Patents

Description

  The present invention relates to, for example, a bearing state diagnosis apparatus that detects sound generated from a rolling bearing that supports a spindle of a machine tool and diagnoses the state of the rolling bearing based on the detected value.

  Bearings are used in rotating machines of many machines. Among the bearings, the rolling bearing is generally composed of an inner ring, an outer ring, a plurality of rolling elements, and a cage for keeping the rolling elements at regular intervals. The inner ring rotates with the shaft, and the outer ring is incorporated in the housing. It has been fixed. Lubricating oil is enclosed or supplied to the bearing, and while the main shaft is rotating, an oil film is formed between the inner ring and the outer ring between the rolling elements.

  If the bearing is rotating normally, there is no problem. However, if the bearing is poorly lubricated, foreign matter enters, wear, excessive load, etc., rotation failure or seizure may occur, the machine may not operate normally. In order to prevent such a situation from occurring, it is necessary to grasp and diagnose the state of the bearing.

  As an apparatus for grasping and diagnosing the state of the bearing in this manner, an apparatus using a vibration sensor (for example, see Patent Document 1), an apparatus using an ultrasonic sensor or a microphone (for example, see Patent Document 2), or an AE sensor is used. An apparatus (see, for example, Patent Document 3) is known.

  In order to grasp the state of the bearing, in order to increase the S / N ratio, it is better to attach the sensor directly to the bearing or as close to the bearing as possible. In the apparatus shown in Patent Document 1 described above, in an apparatus for diagnosing the state of a bearing using a sensor capable of detecting acceleration, in order to increase the S / N ratio, the sensor is directly attached to the bearing or in the vicinity of the bearing. It is necessary to incorporate the parts closer to the bearings, such as housings and spacers. In that case, it is necessary to perform wiring processing, sensor fixing, and the like as compared to a similar component machine that does not incorporate a sensor at the time of assembling the machine, which generally increases assembly man-hours. Also, if the sensor fails and needs to be replaced, a lot of time may have to be spent. Depending on the size and structure of the machine, it is necessary to select a smaller sensor, which may cause problems such as an expensive sensor, insufficient performance, and fewer selectable types. . Further, when the machine is composed of a plurality of bearings, the same number of sensors as the number of bearings is required, so that the apparatus becomes expensive and the components of the apparatus and the machine are complicated. . However, if the mounting position of the sensor is moved away from the vicinity of the bearing, for example, if it is incorporated in the outer periphery or end surface of the housing, the sensor can be easily replaced and the components can be simplified, but the S / N ratio decreases. To do. In that case, of course, it is difficult to mount a sensor for each bearing, and a single sensor diagnoses multiple bearings. When a machine is configured with multiple bearings of the same or similar specifications, Problems such as difficulty in determining whether a problem occurs in the bearing may occur.

  In Patent Document 2, an apparatus for diagnosing the state of a bearing using a sensor capable of detecting sound also measures a change in pressure transmitted through the air, so when the sensor is moved away from the bearing, There is a possibility that the S / N ratio is lowered under the influence of sound generated from other than the bearing, the air temperature around the machine, and the like. In particular, in the case of an ultrasonic sensor having a high measurable frequency range (20 kHz or more), there are many sensors having high directivity characteristics, and further, the higher the measurable frequency sensitivity, the shorter the sound propagation distance. Therefore, it is necessary to attach a sensor near the rolling surface of the bearing.

JP 2007-10415 A JP 2005-164314 A JP 2005-62154 A

  An object of the present invention is to provide a bearing state diagnostic apparatus that solves the above-described problems and is simple in structure and assembly.

According to a first aspect of the bearing state diagnosis apparatus of the present invention, a sound generated from a bearing is detected by a sound sensor, and a detection value of the sound sensor is compared with data prepared in advance to diagnose the state of the bearing. A bearing condition diagnosis device for performing at least one sound sensor disposed at a distance from an outer surface of a cylindrical support housing at least one bearing, and the bearing and the sound sensor are configured to transmit detected sound. The route is connected by a route, and a route for supplying lubricant to the bearing or a route for discharging the lubricant from the bearing is connected in the middle of the detection sound propagation route. An opening / closing operation valve is provided in a portion from the portion where the routes are connected to one of the routes .

According to a second aspect of the bearing state diagnosis apparatus of the present invention, a sound generated from the bearing is detected by a sound sensor, and the detection value of the sound sensor is compared with data prepared in advance to diagnose the state of the bearing. A bearing condition diagnosis device for performing at least one sound sensor disposed at a distance from an outer surface of a cylindrical support housing at least one bearing, and the bearing and the sound sensor are configured to transmit detected sound. A signal generating means which is connected by a path and generates a sound of a specific frequency as a reference signal of the sound sensor, and a propagation means for propagating the sound generated by the signal generating means to the bearing; Has a signal sound propagation path, and in the middle of the signal sound propagation path, a path for supplying the lubricant to the bearing or a path for discharging the lubricant from the bearing is connected, Pathway has been partially shared, the portion toward the one path from the portion where the path to each other are connected, in which opening and closing valve is provided.

According to a third aspect of the bearing state diagnosis apparatus of the present invention, the sound generated from the bearing is detected by a sound sensor, and the detection value of the sound sensor is compared with data prepared in advance to diagnose the state of the bearing. A bearing condition diagnosis device for performing at least one sound sensor disposed at a distance from an outer surface of a cylindrical support housing at least one bearing, and the bearing and the sound sensor are configured to transmit detected sound. A signal generating means which is connected by a path and generates a sound of a specific frequency as a reference signal of the sound sensor, and a propagation means for propagating the sound generated by the signal generating means to the bearing; Has a signal sound propagation path, and either the path for supplying the lubricant to the bearing or the path for discharging the lubricant from the bearing is connected in the middle of the detection sound propagation path As a result, both paths are partially shared, and either the path for supplying the lubricant to the bearing or the path for discharging the lubricant from the bearing is in the middle of the signal sound propagation path. By being connected, both paths are partly shared, and an opening / closing operation valve is provided in a part from the part where the paths are connected to one of the paths .

  In the bearing state diagnosis apparatus according to the present invention, there are the following four combinations of the bearing, the sound sensor, and the detected sound propagation path. First, in the first combination, one sound sensor is arranged at a distance from the outer surface of the cylindrical support body that houses one bearing, and the bearing and the sound sensor are connected by a detection sound propagation path. It is what has been.

  In the second combination, one sound sensor is arranged at a distance from the outer surface of the cylindrical support body that houses a plurality of bearings, and each bearing and the sound sensor are connected by a detection sound propagation path. It is what.

  In the third combination, a plurality of sound sensors are arranged at a distance from the outer surface of the cylindrical support body that accommodates one bearing, and each bearing and the sound sensor are connected by a detection sound propagation path. It is what.

  In the fourth combination, a plurality of paired sound sensors are arranged at a distance from the outer surface of the cylindrical support body that houses a plurality of bearings, and the paired bearings and the sound sensors detect each other. It is connected by the sound propagation path.

  The bearing state diagnosis apparatus according to the present invention has a function of diagnosing the state of a bearing by sound transmitted from a path provided in the bearing. For example, a path leading from the vicinity of the rolling element of the bearing to the outside of the machine is provided, and a sensor capable of detecting a sound having a frequency to be diagnosed is attached to the end of the path. Sound generated by the rotation of the rotating part supported by the bearing is transmitted through the path, and information detected by a sensor capable of detecting sound is collected to diagnose the state of the bearing. For example, compared to the detection result obtained from a sensor capable of detecting the sound when the bearing is rotating normally, damage of the rolling surface, rolling element, cage, contact of the rolling surface and rolling element Since there is a difference in sound when an oil film breakage occurs, the bearing can be diagnosed.

  In the bearing state diagnosis device according to the present invention, when the bearing, the sound sensor, and the detection sound propagation path are the third or fourth combination, the plurality of sound sensors can detect sounds having different frequencies for each sound sensor. Is preferred.

  Compared to the case where only one type of detectable frequency sensor is used, a wider range of frequencies can be measured with high sensitivity. For example, a sensor with a high sensitivity in a low frequency band and a sensor with a high sensitivity in a high frequency band are used, and the sound generated from the bearings is switched to the path of each sensor by a path switchable device, and detection is performed. Therefore, it is possible to deal with bearings of different specifications, different operating conditions, different bearing abnormalities, etc., and more reliable diagnosis is possible.

  In the bearing state diagnosis apparatus according to the present invention, when the bearing, the sound sensor, and the detection sound propagation path are the second to fourth combinations, the detection sound propagation path is switched so that any one of the detection sound propagation paths can be selected. It is preferable that a switching means is provided.

  With the switching device, it is possible to switch the path leading to the sensor and diagnose the state of the bearing, sensor and path. For example, when the rotating part of the machine is supported by a plurality of bearings, the path from the vicinity of the bearing to the device capable of switching the path is configured by an independent path for each bearing. A common path is provided from the device capable of switching the path to the sensor, and a sensor is attached to the end of the path, and by switching the path, a plurality of bearings can be diagnosed by one sensor. This not only reduces the number of sensors, but also simplifies the configuration of the machine and device. Similarly, the path from the vicinity of the bearing to the device whose path can be switched is configured as an independent path for each bearing, but the path from the device whose path can be switched to the sensor should be combined with different lengths. Thus, it is possible to diagnose different frequencies with one sensor.

  In the bearing state diagnosis apparatus according to the present invention, at least a part of the detection sound propagation path is constituted by a pipe, and the pipe has a multilayer structure including at least one of a vibration isolating material layer and a heat insulating material layer. It is preferable.

  It is possible to easily configure a path that is not easily affected by sound other than the sound generated from the bearing. For example, when a three-layer structure using a heat insulating material, a vibration absorbing material, and a steel material is used as a path for a cylindrical pipe, the temperature rises due to heat generated in each part of the machine, and from other than the bearing you want to diagnose It is possible to reduce the influence of the vibration and sound generated, the temperature change around the machine, the sound generated around the machine, and the like. In addition, by combining both the cylindrical pipe and the housing and spacer that are peripheral parts of the bearing with a drill hole that leads from the vicinity of the bearing to the outside of the machine, an optimum path can be configured according to the structure of the machine and device. Is possible.

  In the bearing state diagnosis apparatus according to the present invention, it is preferable that a temperature sensor for detecting the temperature in the detection sound propagation path is provided.

  It is possible to calibrate the value of the sound transmitted from the bearing according to the temperature change in each path. For example, a more accurate diagnosis can be performed by installing a sensor that can detect the temperature in the pipes that make up the path, and detecting the temperature, and taking into account changes in the value due to the effect of sound speed that varies with temperature. Is possible.

  In the second or third aspect of the bearing state diagnostic apparatus according to the present invention, signal generating means for generating a sound of a specific frequency as a reference signal of the sound sensor, and the sound generated by the signal generating means are propagated to the bearing. And propagation means.

  By transmitting a reference signal to the path and detecting the sensor signal in that case, it is compared with the measurement signal when the bearing, sensor, and path are normal, and diagnoses bearing anomalies, sensor failures, path clogging, etc. Is possible. For example, before performing measurement, a reference signal is detected, the value is compared with a value during rotation of the bearing, and a bearing abnormality is detected based on the difference. Alternatively, the reference signal is generated in a state where the reference signal is transmitted and the bearing sound is transmitted, and the signal detected by the sensor is compared with the normal signal to detect the abnormality of the route or the sensor. Therefore, it is possible to diagnose the condition of the bearing with high reliability.

  In the third aspect of the bearing state diagnostic apparatus according to the present invention, the propagation means has a signal sound propagation path, and lubricating oil is supplied to the bearing from one of the detection sound propagation path and the signal sound propagation path. The lubricating oil supplied to the bearing from one side is discharged.

  By making the detection sound propagation path and the signal sound propagation path common with the path for supplying the lubricating oil to the bearing, the path can be simplified. For example, when the lubrication oil supply method to the bearing is an oil-air lubrication method, the route for supplying the sound and the reference signal is made independent by sharing the route for supplying the oil and air with the route for transmitting the sound. It is possible to simplify compared with the case where it provides.

  In the second or third aspect of the bearing state diagnostic apparatus according to the present invention, it is preferable that a temperature sensor for detecting the temperature in the signal sound propagation path is provided.

  Similarly to the case where the temperature sensor for detecting the temperature in the detection sound propagation path is provided, it is possible to cope with the temperature change in the signal sound propagation path.

According to the present invention, diagnosis is performed from the sound transmitted through the path provided in the bearing, thereby improving the maintainability at the time of sensor failure, simplifying the mechanical structure, and improving the diagnostic accuracy by improving the S / N ratio. In addition, the path connecting the bearings and sensors can be switched, which is effective in reducing the number of sensors, simplifying the structure of machines and devices, and improving diagnostic accuracy by detecting with sensors of different specifications. By generating a sensor reference signal, it is possible to detect sensor failure and path clogging, and to perform highly reliable diagnosis.
Further, according to the present invention, the detection sound propagation path and the signal sound propagation path are partly in common with the path for supplying the lubricating oil to the bearing and the path for discharging the lubricating oil from the bearing, so the path is simplified. .

It is a schematic block diagram of the state diagnostic apparatus by the comparative example 1. It is an enlarged view of the bearing diagnosed by the same state diagnostic apparatus. It is the figure and table | surface which showed the relationship of the length, diameter, material, etc. of the path | route of the state diagnostic apparatus, and the sound intensity. It is a flowchart which shows the flow of a process in the state diagnostic apparatus of FIG. It is sectional drawing which made the pipe which comprises the path | route the 3 layer structure. It is a schematic block diagram of the state diagnostic apparatus of the comparative example 2. It is a figure which shows the longitudinal direction sectional view and peripheral device of the condition diagnostic apparatus of the comparative example 3. 10 is a flowchart showing a flow of processing in the state diagnosis device of Comparative Example 3; 10 is a table showing detection results of Comparative Example 3 and estimated abnormalities. 1 is an enlarged view of a bearing according to Embodiment 1. FIG.

  Embodiments and comparative examples of the present invention will be described below with reference to the drawings.

  In the following description, “left and right” means that the left side is the left and the opposite side is the right with reference to FIG. The left side is the front side and the right side is the rear side.

<Comparative Example 1>
Referring to FIG. 1, the main shaft device includes a horizontal hollow shaft main shaft 11, a horizontal cylindrical sleeve 12 surrounding the main shaft 11, and a first bearing which supports the left side of the main shaft 11 with an interval in the axial direction. 21 and the second bearing 22, a third bearing 23 supporting the right side of the main shaft 11, a left housing 24 surrounding the first bearing 21 and the second bearing 22 and fixed to the inner surface of the sleeve 12, and a third A right housing 25 that surrounds the bearing 23 and is fixed to the inner surface of the sleeve 12.

  The outer surface of the main shaft 11 is provided with a large diameter portion 31, a medium diameter portion 32, and a small diameter portion 33 that are successively connected from left to right via steps.

  A stator 35 of a motor 34 is fixed to the inner surface of the sleeve 12 between the second bearing 22 and the third bearing 23. A rotor 36 of the motor 34 is fixed to the outer surface of the main shaft 11 so as to correspond to the stator 35.

  A left inner annular protrusion 37 is provided at the right end of the inner surface of the left housing 24. A right inner annular protrusion 38 is provided at the left end of the inner surface of the right housing 25.

  FIG. 2 shows the upper part of the first bearing 21 in detail. The first bearing 21 includes an outer ring 41 fixed to the inner surface of the left housing 24, an inner ring 42 fixed to the outer surface of the main shaft 11, a plurality of rolling elements 43 interposed between the outer ring 41 and the inner ring 42, The outer ring 41 includes a cage 44 that rotates with the rolling element 43 using the inner surface of the outer ring 41 as a guide surface and holds the rolling element 43 at a constant interval.

  Referring again to FIG. 1, an outer ring spacer 45 fixed to the inner surface of the left housing 24 is interposed between the outer rings 41 of the first bearing 21 and the second bearing 22. An inner ring spacer 46 fixed to the outer surface of the main shaft 11 is interposed between the inner rings 42 of the both bearings 21 and 22.

  A left presser lid 51 is provided on the left opening of the sleeve 12. The left presser lid 51 presses the outer ring 41 of the first bearing 21 and the second bearing 22 together with the outer ring spacer 45 to the left inner annular protrusion 37. A left presser nut 52 is screwed on the right side of the second bearing 22. The left presser nut 52 presses the inner ring 42 of the first bearing 21 and the second bearing 22 together with the inner ring spacer 46 to the steps of the large diameter part 31 and the medium diameter part 32. A right presser lid 53 is applied to the right opening of the sleeve 12. The outer ring 41 of the third bearing 23 is pressed against the right inner annular protrusion 38 by the right pressing lid 53. A right presser nut 54 is screwed on the right side of the third bearing 23. The inner ring 42 of the third bearing 23 is pressed to the step between the medium diameter portion 32 and the small diameter portion 33 by the right presser nut 54.

  Referring again to FIG. 2, in the portion on the left side of the first bearing 21, the first outer through hole 61 is formed in the sleeve 12, the first intermediate through hole 62 is formed in the left housing 24, and the first inner hole is formed in the left presser lid 51. The through holes 63 are formed so as to be continuous in a straight line in the inner and outer directions. One end of the first pipe 64 is connected to the outer end opening of the first outer through hole 61. Referring to FIG. 1, one end of a second pipe 65 is connected to an outer end opening of a through hole (not described in detail) provided in a portion on the right side of the second bearing 22. Further, one end of the third pipe 66 is connected to a third through hole provided in a portion on the right side of the third bearing 23. A series of first detection sound propagation paths 71 are formed by the first outer through hole 61, the first intermediate through hole 62, the first inner through hole 63 and the first pipe 64. A series of second detection sound propagation paths 72 are formed by the second through holes and the second pipe 65. A series of third detection sound propagation paths 73 are formed by the third through holes and the third pipe 66.

  The other ends of the first pipe 64, the second pipe 65, and the third pipe 66 are connected to the collecting pipe 74 and assembled. The collecting pipe 74 is provided with a sound sensor 75. The sound sensor 75 is an ultrasonic sensor whose detectable frequency is near a specific frequency of 20 kHz or more.

  The first pipe 64 is provided with a first opening / closing operation valve 76, the second pipe 65 is provided with a second opening / closing operation valve 77, and the third pipe 66 is provided with a third opening / closing operation valve 78.

  These first to third opening / closing operation valves 76, 77, 78 are driven by a driving device 81. The right presser lid 53 is provided with a speed sensor 82 for detecting the rotational speed of the main shaft 11.

  The information detected by the sound sensor 75 is amplified by the signal amplifying device 83, filtered by the filter device 84, and recorded by the information collecting device 85. At the same time, information of the drive device 81 and the speed sensor 82 is also recorded in the information collecting device 85, and the state of the bearings 21 to 23 is diagnosed by the state diagnosis device 86 using the information.

  Here, with reference to FIGS. 3A, 3 </ b> B, and 3 </ b> C, a path that is adjusted so as to detect sound of a specific frequency will be described. The graph in FIG. 3A is an example showing the relationship between the outer diameter and inner diameter of the pipe, the pipe length, and the sound intensity when sound of a specific frequency is transmitted into the cylindrical pipe. The horizontal axis indicates the pipe length, and the vertical axis indicates the sound intensity. The data plotted in the graph are two types of pipe lengths A and B (A <B), two types of pipe materials are nylon and steel, and the outer and inner diameters of the pipes are φ8 × φ6 and φ10 × φ8. These two cases are compared. Moreover, the graph of FIG.3 (b) is the example which showed the relationship between the length of piping, the bending method of piping, and the strength of sound when the sound of a specific frequency range is transmitted in a cylindrical tube. The horizontal axis indicates the pipe length, and the vertical axis indicates the sound intensity. The data plotted in the graph is 2 types of pipe length A and B (A <B), 1 type of pipe material is copper material, 1 type of pipe outer diameter and inner diameter is φ6 × φ4.5 As for the bending method of the pipe, the unbent one, the one bent into the R shape and the one bent at a right angle are compared. FIG.3 (c) is the table | surface which showed the sound intensity by each condition from the graph of Fig.3 (a) and FIG.3 (b). In other words, the shorter the length of the pipe, the stronger the sound, the stronger the steel material than nylon, the stronger the sound, the larger the inner diameter of the pipe, the stronger the sound, and the stronger the pipe, the stronger the sound. Therefore, when there is a bend in the pipe, the sound tends to be stronger when the arc is bent with an arc than when the bending method is bent at a right angle. Therefore, in this comparative example, a path is configured for each of the three bearings. In consideration of these, the length, the inner diameter of the pipe line, the hole diameter of the hole, the number of times of bending, the bending method, and the like can be as much as possible. It is necessary to align. In particular, attention should be paid to the length because the air column in the path resonates depending on the detected frequency. Since the sensor shown in this comparative example uses the sound sensor 75 whose detectable frequency is near a specific frequency of 20 kHz or higher, the length of the path is the length of the air column that resonates at that frequency. The signal transmitted from the bearing may be amplified.

  Next, the state diagnosis according to Comparative Example 1 will be described with reference to the flowchart of FIG. 4 in addition to FIG. 1 and FIG.

  First, while the main shaft 11 is rotating, the operation valves 76 to 78 of the bearings 21 to 23 to be measured in step S1 are opened. In FIG. 1, the operation valves 77 and 78 of the second and third bearings 23 and 24 are closed while the operation valve 76 of the first bearing 21 is open. Sound generated from the first bearing 21 is transmitted from the first path 71 to the sound sensor 75.

  In step S2, data detection is started, and the signal detected by the sound sensor 75 is amplified by the signal amplifying device 83, and the process proceeds to step S3.

  In step S3, the signal of the sound sensor 75 amplified by the signal amplifier 83 is filtered. In this comparative example, since the frequency of the sound sensor 75 is in the vicinity of a specific frequency of 20 kHz or higher, bandpass filter processing near that frequency is performed, and the process proceeds to step S4.

  In step S4, the signal from the sound sensor 75 is collected by the information collecting device 85 at a sampling period and a detection time determined by the frequency. At the same time, information on the operation valves 76 to 78 and information on the speed sensor 82 are also collected, and the process proceeds to step S5.

  In step S5, the state of the bearing is determined from the collected signals and information. First, the RMS value of the collected signal of the sound sensor 75 is calculated and compared with a threshold value determined from the normal RMS value recorded in advance for each rotation speed. As a result of the comparison, if the collected signal is larger than the threshold value, it is determined as abnormal. Furthermore, in order to judge the detailed phenomenon of abnormality, FFT processing etc. are performed, and the preset rotation frequency component, rolling element passage component, outer ring wound component, inner ring wound component, rolling element wound component, cage damage component Then, comparison is made with the poorly lubricated component of the rolling surface, the poorly lubricated component of the cage, etc., and the process proceeds to step S6. If no abnormal signal is generated, the process returns to step S1 again, the measured operation valve 76 of the first bearing 21 is closed, and the operation valve 77 of the second bearing 22 or the third bearing 23 to be measured next is measured. , 78 are opened, and the process proceeds to step S2.

  If it is determined in step S6 that an abnormality has occurred, the state diagnosis device 86 displays the abnormality occurring in the bearings 21 to 23, generates an alarm signal, etc., and stops the rotation of the spindle 11. Further, the operation of the flowchart of FIG. 4 may be performed while the main shaft 11 is constantly rotating, or may be performed every specific sampling time.

  In Comparative Example 1, an ultrasonic sensor having a detectable frequency near a specific frequency of 20 kHz or more is used as a sensor capable of detecting sound, but a wide range of microphones having a detectable frequency of several Hz to several tens Hz. May be used. However, in that case, it is necessary to pay attention to resonance due to the length of the air column in the path. When a microphone is attached to a path that is open at both ends as in this comparative example, resonance occurs at a specific frequency depending on the length of the air column in the path. As a reference example, when the length of the air column is 200 mm and the temperature is 25 ° C., resonance occurs at “433n” times “2n−1” (n = 1, 2,...) Times. If it is near the frequency at which resonance occurs, it is necessary to change the length of the path. However, conversely, the length of the path may be adjusted and amplified so that the frequency to be detected is near the frequency at which resonance occurs. In addition, a wide frequency may be detected by switching to a path having a different length (not shown). Furthermore, a wide frequency may be detected by moving the position of the microphone manually or automatically in the longitudinal direction of the path (not shown).

  In Comparative Example 1, the operation valves 76 to 78 are opened for each bearing, and the sound generated from the bearing is transmitted to the sound sensor 75, but diagnosis is performed by opening the operation valves 76 to 78 at three or two locations. When an abnormality occurs, the operation valves 76 to 78 may be opened for each bearing to diagnose the sound. By doing so, it is possible to drive the spindle while diagnosing the state of all the bearings 5 at all times, and the operation algorithm is simplified.

  Further, the paths 71 to 73 shown in FIGS. 1 and 2 are constituted by a series of through-hole groups and pipe groups. As shown in FIG. 5, the first pipe 64 constituting the pipe group preferably has a three-layer structure of a steel material layer 91, a vibration isolating material layer 92, and a heat insulating material layer 93. In this way, it is possible to prevent the influence of the temperature of the machine, the vibration and sound generated from other than the bearing, the temperature and sound around the machine, and the like.

<Comparative example 2>
In Comparative Example 2 shown in FIG. 6, the three first to third detection sound propagation paths 71 to 73 assembled in Comparative Example 1 are branched again into three paths, and sensors are respectively provided on the branched paths. It is installed. In Comparative Example 2, parts corresponding to those of Comparative Example 1 are denoted by the same reference numerals in FIG.

  Three fourth to sixth pipes 101 to 103 are connected to the collecting pipe 74. The pipes 101 to 103 are provided with fourth to sixth sound sensors 111 to 113 and fourth to sixth opening / closing operation valves 121 to 123, respectively. The signals of the sound sensors 111 to 113 are amplified by the signal amplifying device 83 for each sensor.

  The frequencies that can be detected by the sound sensors 111 to 113 may be different for each sensor, or may be the same. Further, a wide range of microphones having a detectable frequency of several Hz to several tens Hz may be used. In that case, it is possible to diagnose the sound from the bearings in a wider range with higher sensitivity for each bearing or all at the same time, and with a microphone, rotation frequency component, rolling element passing component, outer ring scratch component, inner ring scratch component, rolling body scratch component It is possible to diagnose the cage scratch component and diagnose the lubrication failure with the sound sensor.

  Also in Comparative Example 2, it is necessary to pay attention to resonance due to the length of the air column in the path. For example, when sound sensors having different detectable frequency ranges are combined, it is necessary to adjust the length of the path suitable for each sensor in consideration of signal amplification due to resonance. In this comparative example, a wide range of frequencies may be detected by combining a plurality of sensors having the same detectable frequency and changing the length of each path. Further, a wide frequency may be detected by manually or automatically moving the sensor position in the longitudinal direction of the path (not shown).

  Also, the pipe constituting the path of FIG. 6 has a three-layer structure, similar to that shown in FIG. You may make it prevent.

<Comparative Example 3>
Next, Comparative Example 3 will be described with reference to FIG.

In Comparative Example 3, a reference signal having a specific frequency is propagated to the bearings 21 to 23 shown in Comparative Example 1. In Comparative Example 3, as in Comparative Example 2, portions corresponding to Comparative Example 1 are denoted by the same reference numerals in FIG. 7 and description thereof is omitted.
A branch pipe 131 is arranged in parallel with the collecting pipe 74. The branch pipe 131 is provided with a reference signal generator 132.

  The reference signal generator 132 is operated by the reference signal controller 133. The reference signal is determined by the specification of the sound sensor 75. For example, in the case of a sound sensor whose detectable frequency is in the vicinity of a specific frequency of 20 kHz or higher, a device that generates a reference signal of that frequency is used, and the frequency that can be detected is a wide range of several Hz to several tens Hz. When a microphone is used, a device that generates a signal having a specific frequency at that frequency is used. In this comparative example, since the sound sensor 75 is used, a device that generates a reference signal having a specific frequency that can be detected by the sound sensor 75 is used.

One end of a seventh pipe 141 and an eighth pipe 142 is connected to the branch pipe 131. The seventh pipe 141 is provided with a seventh opening / closing operation valve 151, and the eighth pipe 142 is provided with an eighth opening / closing operation valve 152. Although the other end of the seventh pipe 141 will not be described in detail, the first and second bearings 21 and 22 are formed by the through hole group according to the through hole group constituting the first to third detection sound propagation paths 71 to 73. The through hole group is bifurcated, one of which is opened to the right of the first bearing 21 and the other is opened to the left of the second bearing 22. . Similarly, the other end of the eighth pipe 142 is opened to the left of the third bearing 23 through the through hole group.
A first signal sound propagation path 161 is formed by the seventh pipe 141 and one branch through hole group. A second signal sound propagation path 162 is formed by the seventh pipe 141 and the other branch through hole group. A third signal sound propagation path 163 is formed by the eighth pipe 142 and the through hole group.

  In Comparative Example 3, as in Comparative Example 1, the length of the path, the inner diameter of the pipe, the diameter of the hole, the number of times of bending, the bending method, and the like are set as much as possible to transmit a stable reference signal to the bearings 21 to 23 It is necessary to align. In particular, regarding the length, attention must be paid because the air column in the path resonates according to the frequency of the reference signal transmitted to the bearings 21 to 23 as in the first comparative example. Since the sensor shown in this comparative example uses the sound sensor 75, even if the reference signal transmitted to the bearings 21 to 23 is amplified by setting the length of the path to the length of the air column that resonates at that frequency. Good.

  Next, the bearing diagnosis function in the comparative example 3 will be described with reference to FIGS. 7, 8, and 9.

  First, in step S11, in order to transmit the reference signal to the bearings 21 to 23, the operation valves 151 and 152 are opened, and the process proceeds to step S12. In FIG. 7, the operation valve 151 for transmitting the reference signal to the first and second bearings 21 and 22 is open, and the operation valve 152 of the third bearing is closed.

  In step S2, by opening the operation valves 76 to 78 of the bearings 21 to 23 to be diagnosed, the reference signal is transmitted from the gap between the outer ring 41 and the inner ring 42 of the bearings 21 to 23 to the sound sensor 75 through the detection sound propagation paths 71 to 73. It is transmitted. In FIG. 7, the operation valve 78 of the third bearing 23 is closed while the operation valves 76, 77 of the first and second detection sound propagation paths 71, 72 of the first and second bearings 21, 22 are open. Therefore, the first and second detection sound propagation paths 71 and 72 of the first and second bearings 21 and 22 or the sound sensor 75 can be diagnosed.

  In step S13, a reference signal is generated from the reference signal generator 132, and the reference signal is transmitted between the outer ring 41 and the inner ring 42 of the first and second bearings 21, 22 from the first and second signal sound propagation paths 161, 162. From the gap, the first and second detected sound propagation paths 71 and 72 are transmitted to the sound sensor 75, and the process proceeds to step S14. In this comparative example 3, since the sound sensor 75 whose detectable frequency is near a specific frequency of 20 kHz or more is used, the reference signal is a reference signal of that frequency.

  In step S14, data detection is started, and the signal detected by the sound sensor 75 is amplified by the signal amplifying device 83, and the process proceeds to step S15.

  In step S15, the amplified sound sensor 75 signal is filtered. In this comparative example 3, since the detectable frequency is the sound sensor 75 in the vicinity of a specific frequency of 20 kHz or more, the bandpass filter process of that frequency is performed, and the process proceeds to step S16.

  In step S16, the signal of the sound sensor 75 is collected by the information collecting device 85 at a sampling period and a detection time determined by a detectable frequency. At the same time, information on the operation valves 76 to 78 is also collected, and the process proceeds to step S17.

  In step S17, the state of the path and the sound sensor 75 is normal depending on whether the RMS value of the collected signal is within a set range, too large, or too small as compared with a reference value measured in advance. If it is abnormal, the process proceeds to step S18.

  In step S18, it is determined from the information of the first to third operation valves 76 to 78 and the seventh and eighth operation valves 151 and 152 which of the bearings 21 to 23 has been detected, and the detection is still completed. If not, the process returns to step S11. If completed, the process proceeds to step S19.

  In step S19, when all the data has been collected, it is determined which route and device is abnormal.

  In the table of FIG. 9, the first, second, and third row paths indicate the route from the reference signal generator 132 to the sound sensor 75 through the bearings 21 to 23, the first row, the second row, and the like. The third row of paths includes first to third detection sound propagation paths 71 to 73, respectively.

  In CASE 1, since the detection data of the first, second, and third rows of the bearings 21 to 23 are normal, it is determined that no abnormality has occurred. In CASE5, the detection data of the path in the first column is abnormal, and the detection data in the second column and the third column are normal. Therefore, an abnormality has occurred on the sound sensor 75 side of the path in the first column. to decide.

  When step S19 is completed, the operation is terminated. If all paths and devices are normal, the data collected in the main detection is rewritten as reference data. The operation of the flowchart of FIG. 8 may be detected when the spindle 11 before the spindle device is not operating, or when the spindle 11 is not rotating during the operation, and acquires reference data. May be.

Also in Comparative Example 3, it is preferable that the pipe forming the path has a three-layer structure.
By using the reference data acquired in the flowchart of FIG. 8 for the diagnosis of the bearings 21 to 23, a highly reliable diagnosis is possible even when the spindle device, the sound sensor 75, the aging of the path, the environmental change around the device, etc. occur. Can be done. This can be achieved by comparing the detection data of the sound sensor 75 with the reference data when the diagnosis of the spindle device is started and the bearings 21 to 23 are diagnosed as in the flowchart of FIG.

  In Comparative Example 3, the sound sensor 75 having a detectable frequency in the vicinity of a specific frequency of 20 kHz or more is used, but a sensor having a detectable frequency of several Hz to several tens of kHz may be used. In that case, the reference signal generator 132 is also adapted to the sensor. Furthermore, although one sound sensor 75 is attached in Comparative Example 3, a plurality of sound sensors 75 may be attached. In this case, if the detectable frequency is different, a reference signal generator 132 that is adapted to the device is also added.

<Embodiment 1>
Next, the first embodiment will be described. In the first embodiment, lubricating oil can be supplied to and discharged from the bearings 21 to 23 shown in Comparative Example 3.

  Referring to FIG. 10A, the lubricating oil supply pipe 171 is joined to the first pipe 64 that extends upward from the first bearing 21. A ninth opening / closing operation valve 172 is provided at a portion from the joining portion of the first pipe 64 and the lubricating oil supply pipe 171 toward the first pipe 64.

  Referring to FIG. 10 (b), the seventh pipe 141 extends downward from the first bearing 21, and the lubricating oil discharge pipe 173 is branched from the middle of the seventh pipe 141. A tenth opening / closing operation valve 174 is provided at a portion from the branch portion of the seventh pipe 141 and the lubricating oil discharge pipe 173 toward the seventh pipe 141.

  By opening / closing the ninth opening / closing operation valve 172 and the tenth opening / closing operation valve 174, one of the sound propagation path and the lubricating oil path is brought into communication with the first bearing 21. Propagation or lubrication oil supply / discharge.

  In the first embodiment, the route for supplying the lubricating oil, the route for transmitting the sound of the bearings 21 to 23, the route for discharging the lubricating oil, and the route for transmitting the reference signal to the bearing are partially common, so the route is simplified. Is done. In the first embodiment, the route for supplying the lubricating oil and the route for transmitting the sound of the bearings 21 to 23 are partially shared, the route for discharging the lubricating oil, and the route for transmitting the reference signal to the bearings 21 to 23. Is partially shared, but the reverse is also possible. In addition, a form in which the path for supplying the lubricant and the path for transmitting the sound of the bearings 21 to 23 are partially shared, the path for discharging the lubricant, and a path for transmitting the reference signal to the bearings 21 to 23 are partially shared. The combined form may be used in combination with the same device, or either one may be used.

  In Comparative Example 1, Comparative Example 2, Comparative Example 3 and Embodiment 1, the path provided in the vicinity of the bearing adjusted to detect the sound of the specific frequency, and adjustment to transmit the reference signal By attaching a sensor capable of measuring the temperature in the path provided in the vicinity of the bearing and measuring the temperature of the air in the path through which the sound is transmitted, the sound transmitted from the bearings 21 to 23, or the bearings 21 to It is possible to adjust the value of the reference signal transmitted to 23 according to the temperature change in each path. For example, the temperature is detected by attaching a sensor capable of detecting the temperature in a pipe constituting the path. When the resonance of the air column in the path is used, the sound speed changes depending on the temperature change of the air. If the path length is the same, the frequency at the time of resonance changes, so the value detected by the sensor changes. To do. If it is not desired to change the detected frequency, it can be handled by moving the position of the sensor in the longitudinal direction of the path or changing the length of the path.

21-23 First to third bearings
71-73 First to third detection sound propagation paths
75 sound sensor
161-163 First to third signal sound propagation paths
171 Lubricating oil supply pipe
172 9th open / close valve
173 Lubricating oil discharge pipe
174 10th open / close operation valve

Claims (3)

A bearing state diagnosis device for detecting a sound generated from a bearing by a sound sensor and comparing a detection value of the sound sensor with data prepared in advance, and diagnosing the state of the bearing, wherein at least one bearing is At least one sound sensor is arranged at a distance from the outer surface of the accommodated cylindrical support, the bearing and the sound sensor are connected by a detection sound propagation path, and are located in the middle of the detection sound propagation path. By connecting a route for supplying lubricating oil to the bearing or a route for discharging the lubricating oil from the bearing, both of the routes are partly shared, and one of the parts where the paths are connected Bearing state diagnosis device provided with an opening / closing operation valve in a part toward the path of the . A bearing state diagnosis device for detecting a sound generated from a bearing by a sound sensor and comparing a detection value of the sound sensor with data prepared in advance, and diagnosing the state of the bearing, wherein at least one bearing is At least one sound sensor is arranged at a distance from the outer surface of the cylindrical support body that is housed, and the bearing and the sound sensor are connected by a detection sound propagation path and specified as a reference signal of the sound sensor. Signal generating means for generating a sound of a frequency of the above and a propagation means for propagating the sound generated by the signal generating means to the bearing, the propagation means has a signal sound propagation path, in the middle of the path, by the path for discharging the lubricating oil from the path or bearing for supplying lubricating oil to the bearing are connected, and both paths are partially shared, connection paths to each other Is the portion directed by the parts are to one path, opening and closing valve is that bearing condition diagnosis apparatus is provided. A bearing state diagnosis device for detecting a sound generated from a bearing by a sound sensor and comparing a detection value of the sound sensor with data prepared in advance, and diagnosing the state of the bearing, wherein at least one bearing is At least one sound sensor is arranged at a distance from the outer surface of the cylindrical support body that is housed, and the bearing and the sound sensor are connected by a detection sound propagation path and specified as a reference signal of the sound sensor. A signal generating means for generating a sound of a frequency of and a propagating means for propagating the sound generated by the signal generating means to the bearing, the propagating means has a signal sound propagation path, and the detected sound propagation In the middle of the path, either one of the path for supplying the lubricating oil to the bearing and the path for discharging the lubricating oil from the bearing is connected, so that both paths are partially shared. In the middle of the tone propagation path, by any other of the path for discharging the lubricating oil from the path and bearing for supplying lubricating oil is connected to the bearing, both paths is partially common A bearing state diagnosis device in which an opening / closing operation valve is provided in a portion from the portion where the routes are connected to one of the routes .

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