Vibration monitoring device, supercharger, and vibration monitoring method

Abstract

This vibration monitoring device is provided with: a rotation sensor that outputs a rotation signal synchronized with the rotation of a rotating shaft; an output device that outputs a natural vibration frequency filter command value calculated on the basis of the natural vibration frequency of the rotating shaft; and a self-excited vibration band-pass filter that, by inputting the rotation signal and the natural vibration frequency filter command value, extracts, from the rotation signal, a signal of a pass band included in a pass range set on the basis of the natural vibration frequency filter command value, as a self-excited vibration signal in which information on the self-excited vibration of the rotation shaft can be acquired.

Description

Technical Field

[0001] The invention relates to a vibration monitoring device, a supercharger and a vibration monitoring method. This application claims priority based on Japanese Patent Application No. 2022-165172 filed with the Japan Patent Office on October 14, 2022, and the contents of which are incorporated herein by reference. Background Art

[0002] For example, Patent Document 1 discloses a technique in which a passband signal suitable for evaluating vibration of a rotating shaft can be extracted from a rotation signal synchronized with the rotation of the rotating shaft by setting a passband of a filter according to the rotation speed of the rotating shaft. Previous technical literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-135868 Summary of the invention Technical issues to be solved by the invention

[0004] In the technology described in Patent Document 1, it is possible to evaluate the forced vibration of the rotating shaft, which is caused by the unbalanced structure of the rotating shaft itself or the forced vibration caused by the contact between the rotating shaft and the stationary part, based on the rotation signal of the rotating shaft. However, in the technology described in Patent Document 1, it is difficult to evaluate the self-excited vibration of the rotating shaft (for example, the oil film oscillation caused by the mutual resonance between the rotating shaft and the oil applied to the rotating shaft) based on the rotation signal of the rotating shaft. In addition, it is difficult to evaluate the nonlinear forced vibration of the rotating shaft (for example, the vibration caused by the looseness caused by the poor assembly of the bearing part of the bearing rotating shaft) based on the rotation signal of the rotating shaft.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a vibration monitoring device and a vibration monitoring method capable of evaluating the self-excited vibration of a rotating shaft or the nonlinear forced vibration of a rotating shaft based on a rotation signal of the rotating shaft. Means for solving technical problems

[0006] In order to achieve the above-mentioned purpose, the vibration monitoring device involved in the present invention comprises: a rotation sensor, which outputs a rotation signal synchronized with the rotation of a rotating shaft; an output device, which outputs a natural vibration frequency filter command value calculated based on the natural vibration frequency of the rotating shaft; and a self-excited vibration bandpass filter, which extracts a signal of a passband included in a pass range set according to the natural vibration frequency filter command value from the rotation signal by inputting the rotation signal and the natural vibration frequency filter command value, as a self-excited vibration signal capable of obtaining information on the self-excited vibration of the rotating shaft.

[0007] In order to achieve the above-mentioned purpose, the vibration monitoring device involved in the present invention comprises: a rotation sensor, which outputs a rotation signal synchronized with the rotation of a rotating shaft; a filter command value output device, which outputs a division filter command value obtained by dividing the filter command value corresponding to the rotation speed of the rotating shaft calculated based on the rotation signal by n (where n=1, 2, ... is a natural number); and a nonlinear forced vibration bandpass filter, which extracts a signal of a passband including a nonlinear center frequency set according to the division filter command value from the rotation signal by inputting the rotation signal and the division filter command value, as a forced vibration signal capable of obtaining information on the forced vibration of the rotating shaft.

[0008] In order to achieve the above-mentioned purpose, the vibration monitoring method involved in the present invention includes the following steps: outputting a rotation signal synchronized with the rotation of a rotating shaft; outputting a natural vibration frequency filter command value calculated according to the natural vibration frequency of the rotating shaft; and extracting a passband signal included in a pass range set according to the natural vibration frequency filter command value from the rotation signal by inputting the rotation signal and the natural vibration frequency filter command value, as a self-excited vibration signal capable of obtaining information on the self-excited vibration of the rotating shaft.

[0009] In order to achieve the above-mentioned purpose, the vibration monitoring method involved in the present invention includes the following steps: outputting a rotation signal synchronized with the rotation of a rotating shaft; outputting a division filter command value obtained by dividing a filter command value corresponding to the rotation speed of the rotating shaft calculated based on the rotation signal by n (where n=1, 2, ... is a natural number); and extracting a passband signal including a nonlinear center frequency set according to the division filter command value from the rotation signal by inputting the rotation signal and the division filter command value as a forced vibration signal capable of obtaining information on the forced vibration of the rotating shaft. Effects of the Invention

[0010] According to the vibration monitoring device and the vibration monitoring method of the present invention, it is possible to evaluate the self-excited vibration of the rotating shaft or the nonlinear forced vibration of the rotating shaft based on the rotation signal of the rotating shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a diagram schematically showing the structure of a supercharger to which the vibration monitoring device according to the first embodiment is applied. Figure 2 It is a diagram schematically showing the structure of the marking portion according to the first embodiment. Figure 3 It is a waveform diagram of a rotation signal output by the rotation sensor according to the first embodiment. Figure 4This is a schematic functional block diagram of the output device according to the first embodiment. Figure 5 Yes Figure 3 The waveform diagram of the rotation pulse signal obtained by dividing the rotation signal. Figure 6 It is a diagram showing a characteristic table of the low-pass filter according to the first embodiment. Figure 7 It is a graph showing the amplitude-frequency characteristics of the bandpass filter. Figure 8 This is a diagram showing an example of display content displayed on the display device according to the first embodiment. Fig. 9 This is a Campbell diagram of the rotation axis according to the first embodiment. Fig.10 It is a diagram schematically showing the configuration of a vibration monitoring device according to a second embodiment. Fig.11 This is a schematic functional block diagram of an output device according to the second embodiment. Fig.12 It is a graph showing the amplitude-frequency characteristics of the nonlinear forced vibration bandpass filter. Fig.13 This is a diagram showing an example of display content displayed on the display device according to the second embodiment. Fig.14 It is a diagram schematically showing the configuration of a vibration monitoring device according to a third embodiment. Fig.15 This is a flowchart of a vibration monitoring method according to one embodiment. Fig.16 is a flow chart of a vibration monitoring method according to another embodiment. DETAILED DESCRIPTION

[0012] Hereinafter, a vibration monitoring device, a supercharger, and a vibration monitoring method according to an embodiment of the present invention will be described with reference to the accompanying drawings. The above embodiment is only one mode of the present invention and does not limit the present invention, and any changes can be made within the scope of the technical concept of the present invention.

[0013] <First embodiment> (Structure of supercharger) Figure 1 1 is a diagram schematically showing the structure of a supercharger 100 to which the vibration monitoring device 1 according to the first embodiment is applied. The supercharger 100 is not particularly limited, and is, for example, an exhaust gas turbocharger mounted on a ship and used to supercharge the intake air of an engine. In the present invention, the exhaust gas turbocharger is used as an example for description.

[0014] like Figure 1 As shown, the supercharger 100 includes a rotating shaft 102, a compressor 104, a turbine 106, and the vibration monitoring device 1 according to the first embodiment. Figure 1 A compressor 104 is provided at the left end portion of the rotating shaft 102. Figure 1 A turbine 106 is provided at the right end portion in the figure. The rotating shaft 102 connects the compressor 104 and the turbine 106.

[0015] The compressor 104 compresses the intake air and supplies it to an engine (not shown). When the exhaust gas discharged from the engine passes through the turbine 106, the turbine 106 converts the energy of the exhaust gas into the rotational energy of the turbine 106. In addition, the rotating shaft 102 rotates around the axis O as the turbine 106 rotates. The compressor 104 is driven by the rotation of the rotating shaft 102.

[0016] exist Figure 1 In the illustrated embodiment, the rotating shaft 102 includes a marking portion 108 configured to make a rotation signal A described later have a pulse waveform. The marking portion 108 is provided between the compressor 104 and the turbine 106 in the direction of the axis O. The marking portion 108 is provided on the turbine 106 side between the compressor 104 and the turbine 106 in the direction of the axis O. In some embodiments, the marking portion 108 is provided on one end side of the rotating shaft 102 closer to the compressor 104 in the direction of the axis O.

[0017] A configuration example of the marking portion 108 will be described. Figure 2 1 is a diagram schematically showing the structure of the marking portion 108 according to the first embodiment. Figure 2 In the example shown in , the rotating shaft 102 includes an inner rotating body 110 and an outer rotating body 112. The inner rotating body 110 of the rotating shaft 102 rotates around the axis O as the turbine 106 rotates. The outer rotating body 112 is formed with a hole 114 that is embedded in the inner rotating body 110. In other words, the outer rotating body 112 is mounted on the inner rotating body 110 in a manner that covers the outer peripheral surface of the inner rotating body 110. The outer rotating body 112 rotates as the inner rotating body 110 embedded in the hole 114 rotates. The outer rotating body 112 includes a groove 118 formed on the outer peripheral surface 116. When the groove 118 is not formed, the outer peripheral surface 116 of the outer rotating body 112 has a circular shape. The groove 118 is formed by cutting off a portion 117 of the circular outer peripheral surface 116 toward the axis O. In Figure 2In the illustrated embodiment, the outer rotating body 112 includes two grooves 118, and the outer peripheral surface 116 has an elliptical shape. One groove 118 is located on the opposite side of the other groove 118 across the axis O. The outer rotating body 112 has two grooves 118 formed symmetrically about the axis O. This outer rotating body 112 corresponds to the marking portion 108.

[0018] In addition, as long as the marking portion 108 is configured so that the rotation signal A has a pulse waveform, it is not limited to Figure 2 For example, the marking portion 108 (outer rotating body 112 ) may include a protrusion that protrudes radially outward from a portion 117 of the outer peripheral surface 116 instead of the groove 118 .

[0019] (Structure of vibration monitoring device according to first embodiment) like Figure 1 As shown, the vibration monitoring device 1 includes a rotation sensor 2, an output device 4, and a self-excited vibration bandpass filter 6. The self-excited vibration bandpass filter 6 is electrically connected to the rotation sensor 2 so as to obtain an output value (rotation signal A) of the rotation sensor 2. The self-excited vibration bandpass filter 6 is electrically connected to the output device 4 so as to obtain an output value (natural vibration frequency filter command value B1) of the output device 4.

[0020] The rotation sensor 2 outputs a rotation signal A synchronized with the rotation of the rotating shaft 102. The rotation sensor 2 is an eddy current displacement sensor that detects the distance d to the outer peripheral surface 116 of the rotating shaft 102 by generating eddy currents on the outer peripheral surface 116 of the rotating shaft 102. More specifically, the rotation sensor 2 is composed of a coil that generates a high-frequency magnetic flux, and the change of the eddy current generated on the outer peripheral surface 116 of the rotating shaft 102 as a target (measurement object) is detected as a change in the impedance of the coil by the high-frequency magnetic flux generated by the coil. That is, the rotation sensor 2 detects the change of the distance d accompanying the rotation of the rotating shaft 102 as a change in the impedance of the coil, and is configured to obtain the maximum output when the outer peripheral surface 116 of the rotating shaft 102 is closest to the rotation sensor 2.

[0021] In addition, the rotation sensor 2 is not limited to an eddy current displacement sensor. In some embodiments, the rotation sensor 2 is a laser displacement sensor, which includes a laser head for irradiating a laser beam, irradiating the laser beam from the laser head to the outer peripheral surface 116 of the rotating shaft 102, and detecting the distance from the laser head to the outer peripheral surface 116 of the rotating shaft 102 based on the reflected light of the laser beam.

[0022] Figure 3 : is a waveform diagram of the rotation signal A output by the rotation sensor 2 according to the first embodiment. Figure 3As shown, since the marking portion 108 (outer rotating body 112) of the rotating shaft 102 includes the groove 118, the rotation signal A has a pulse waveform formed along with the rotation of the rotating shaft 102. That is, during the rotation of the rotating shaft 102, when the rotation sensor 2 and the groove 118 are opposite to each other, the displacement changes greatly. On the other hand, during the rotation of the rotating shaft 102, when the rotation sensor 2 and the groove 118 are not opposite to each other, the displacement changes little. In the first embodiment, the marking portion 108 has two grooves 118, so two pulses (the portion 120 where the displacement of the waveform changes greatly) appear when the rotating shaft 102 rotates one circle.

[0023] The output device 4 outputs the natural vibration frequency filter command value B1 calculated based on the natural vibration frequency Fa of the rotating shaft 102. The method for measuring the natural vibration frequency Fa of the rotating shaft 102 is not particularly limited, but for example, the dangerous speed (natural vibration frequency Fa) of the rotating shaft 102 can be evaluated by performing a bending vibration analysis of the shaft system using rotor dynamics analysis (ROT-CAE), or the natural vibration frequency Fa (resonance frequency) can be measured by mechanically applying forced vibration to the rotating shaft 102. The output device 4 converts the natural vibration frequency Fa of the rotating shaft 102 by a predetermined conversion method and calculates the natural vibration frequency filter command value B1. The natural vibration frequency filter command value B1 is a voltage value or a current value.

[0024] The self-excited vibration bandpass filter 6 outputs (extracts) a self-excited vibration signal C by inputting a rotation signal A and a natural vibration frequency filter command value B1. The self-excited vibration signal C is a signal that can obtain information about the self-excited vibration of the rotating shaft 102. The information about the self-excited vibration is, for example, the self-excited vibration frequency, the magnitude of the self-excited vibration, or the speed of the self-excited vibration. The self-excited vibration bandpass filter 6 is configured to set a first pass range R1 according to the natural vibration frequency filter command value B1. In the first embodiment, the first pass range R1 is greater than 0.9 times the natural vibration frequency Fa of the rotating shaft 102 and less than 1.1 times the natural vibration frequency. For example, the natural vibration frequency Fa of the rotating shaft 102 is 25 Hz, and the first pass range R1 is greater than 22.5 Hz and less than 27.5 Hz.

[0025] The self-excited vibration bandpass filter 6 passes the passband signal included in the first pass range R1 of the rotation signal A output by the rotation sensor 2, and cuts off the non-passband signal not included in the first pass range R1. In addition, the self-excited vibration bandpass filter 6 extracts the rotation signal A included in the first pass range R1 from the rotation signal A as the self-excited vibration signal C.

[0026] In the first embodiment, as Figure 1As shown, the vibration monitoring device 1 further includes a filter command value output device 8, a low-pass filter 10, a band-pass filter 12, and a display device 14. The filter command value output device 8, the low-pass filter 10, and the band-pass filter 12 are electrically connected to the rotation sensor 2, respectively, so as to obtain the output value (rotation signal A) of the rotation sensor 2. The low-pass filter 10 is electrically connected to the filter command value output device 8, so as to obtain the output value (filter command value B2) of the filter command value output device 8. The band-pass filter 12 is electrically connected to the filter command value output device 8 via the low-pass filter 10, so as to obtain the output value (filter command value B2) of the filter command value output device 8. In addition, in some embodiments, the band-pass filter 12 can obtain the filter command value B2 from the filter command value output device 8 without passing through the low-pass filter 10.

[0027] The filter command value output device 8 outputs a filter command value B2 corresponding to the rotation speed An of the rotating shaft 102 calculated based on the rotation signal A. This filter command value output device 8 is a computer such as an electronic control device, and has a processor such as a CPU or GPU, a memory such as a ROM or RAM, and an I / O interface, etc. (not shown). The filter command value output device 8 performs actions (calculations, etc.) according to the instructions of the program loaded into the memory by the processor, thereby realizing the various functional units of the filter command value output device 8. Figure 4 , each functional unit of the filter command value output device 8 involved in the first embodiment is described.

[0028] Figure 4 1 is a schematic functional block diagram of the filter command value output device 8 according to the first embodiment. Figure 4 As shown, the filter command value output device 8 includes a frequency dividing section 122 , a counter section 124 , a display section 126 , and a filter command value output section 128 .

[0029] Figure 5 Yes Figure 3 The waveform diagram of the rotation pulse signal Ap obtained by dividing the rotation signal A. Figure 5 As shown, the frequency divider 122 divides the rotation signal A outputted from the rotation sensor 2 and converts it into a rotation pulse signal Ap including one pulse (a portion 130 where the displacement of the waveform changes significantly) when the rotating shaft 102 rotates once.

[0030] The counter unit 124 counts the number of pulses included in the rotation pulse signal Ap per unit time, and calculates the rotation speed An of the rotating shaft 102. The display unit 126 causes the display device 14 to display the rotation speed An of the rotating shaft 102 calculated by the counter unit 124. In addition, the display unit 126 may cause a device other than the display device 14 to display the rotation speed An of the rotating shaft 102.

[0031] The filter command value output unit 128 outputs a filter command value B2 corresponding to the rotation speed An of the rotating shaft 102 calculated by the counter unit 124. In the first embodiment, the filter command value B2 is a voltage value obtained by converting the rotation speed An of the rotating shaft 102 by a predetermined conversion method. The conversion method is set according to the characteristics of the low-pass filter 10 described later. In the first embodiment, if the rotation speed An of the rotating shaft 102 increases, the filter command value B2 (voltage value) also increases. In some embodiments, the rotation speed An of the rotating shaft 102 and the filter command value B2 are proportional to each other. In some embodiments, the filter command value B2 is a current value obtained by converting the rotation speed An of the rotating shaft 102 by a predetermined conversion method.

[0032] like Figure 1 As shown, by inputting the rotation signal A and the filter command value B2, the low pass filter 10 outputs (extracts) a vibration signal E. The vibration signal E is a signal that can obtain vibration information of the rotating shaft 102. The vibration information is, for example, the vibration frequency, the vibration magnitude, or the vibration speed.

[0033] The low-pass filter 10 is configured to set a cutoff frequency P according to the filter command value B2 (voltage value). The low-pass filter 10 allows the rotation signal A outputted by the rotation sensor 2 to pass the rotation signal A whose frequency is less than the cutoff frequency P, and cuts off the rotation signal A whose frequency is greater than the cutoff frequency P. The low-pass filter 10 extracts the rotation signal A whose frequency is less than the cutoff frequency P from the rotation signal A as the vibration signal E.

[0034] Here, the setting of the cutoff frequency P will be described. Figure 6 1 is a diagram showing a characteristic table of the low-pass filter 10 according to the first embodiment. Figure 6 In the figure, the horizontal axis is the frequency expressed in a logarithmic scale and the vertical axis is the decibel value. Figure 6 In the figure, V1 represents the characteristics of the low-pass filter 10 when the voltage value (filter instruction value B2) is 0.01V, V2 represents the characteristics of the low-pass filter 10 when the voltage value is 0.1V, V3 represents the characteristics of the low-pass filter 10 when the voltage value is 1V, and V4 represents the characteristics of the low-pass filter 10 when the voltage value is 10V.

[0035] The decibel value is equivalent to the signal strength. When the decibel value is less than 0, the vibration signal E extracted by the low-pass filter 10 is attenuated. Figure 6 As shown in FIG. 1 , at each voltage value (V1 to V4), as the frequency increases, the decibel value decreases, and the attenuation rate of the vibration signal E increases. More specifically, when the voltage value input to the low-pass filter 10 is 0.1V ( Figure 6V2 in the figure), the vibration signal E is extracted by cutting off the rotation signal A above 1kHz in the rotation signal A input to the low-pass filter 10. In the first embodiment, the low-pass filter 10 sets the cutoff frequency P to a decibel value of 0. For example, when the voltage value is 0.1V, the low-pass filter 10 sets the cutoff frequency to 1kHz.

[0036] The vibration signal E extracted by the low-pass filter 10 is the rotation signal A of the rotating shaft 102 less than the cutoff frequency P, and has a waveform similar to a net actual vibration signal generated by the vibration of the rotating shaft 102 .

[0037] like Figure 1 As shown, the bandpass filter 12 outputs (extracts) a forced vibration signal (hereinafter referred to as “first forced vibration signal D1 ”) by inputting the rotation signal A and the filter command value B2 . The first forced vibration signal D1 is a signal that can obtain information on the forced vibration of the rotating shaft 102 .

[0038] The bandpass filter 12 is configured to set the center frequency Fb according to the filter command value B2. The bandpass filter 12 allows the passband signal included in the second pass range R2 including the center frequency Fb in the rotation signal A output by the rotation sensor 2 to pass, and cuts off the non-passband signal not included in the second pass range R2. In addition, the bandpass filter 12 extracts the rotation signal A included in the second pass range R2 from the rotation signal A as the first forced vibration signal D1.

[0039] Figure 7 is a graph showing the amplitude-frequency characteristics of the bandpass filter 12. Figure 7 In the figure, the horizontal axis is the frequency expressed in a logarithmic scale and the vertical axis is the decibel value. Figure 7 In the figure, V5 represents the characteristics of the band-pass filter 12 when the voltage value (filter instruction value B2) is 0.1V, V6 represents the characteristics of the band-pass filter 12 when the voltage value is 1V, and V7 represents the characteristics of the band-pass filter 12 when the voltage value is 10V.

[0040] exist Figure 7 In the example, the decibel value is equivalent to the signal strength. When the decibel value is less than 0, the second forced vibration signal D2 extracted by the bandpass filter 12 is attenuated. Figure 7 As shown in FIG. 1 , in each voltage value (V5 to V7), as the frequency moves away from the center frequency Fb of the passband of the bandpass filter 12, the decibel value decreases, and the attenuation rate of the first forced vibration signal D1 increases. The center frequency Fb is set according to the filter command value B2 (a value corresponding to the rotation speed An) output by the filter command value output device 8. Specifically, the center frequency Fb is set to be equal to the counter unit 124 (reference Figure 4 ) is consistent or approximately consistent with the rotation speed An of the rotating shaft 102 counted. For example, the bandpass filter 12 can attenuate the first forced vibration signal D1 according to the filter command value B2 to satisfy 0.8C≤Fb≤1.2C. Furthermore, in the case where the rotation speed An of the rotating shaft 102 is proportional to the filter command value B2, the center frequency Fb can be set in a manner that the filter command value B2 is proportional to the center frequency Fb. Furthermore, the upper limit and lower limit of the passband of the bandpass filter 12 are set on both sides of the center frequency Fb according to the filter command value B2.

[0041] The first forced vibration signal D1 extracted by the bandpass filter 12 becomes a signal that can evaluate the vibration synchronized with the rotation of the rotating shaft 102 (vibration having a vibration frequency that is 1 times or approximately 1 times the rotation speed An) by setting the center frequency Fb of the bandpass filter 12 to be the same or approximately the same as the rotation speed An of the rotating shaft 102.

[0042] The display device 14 simultaneously displays the information of the self-excited vibration of the rotating shaft 102 obtained according to the self-excited vibration signal C, the information of the total vibration of the rotating shaft 102 (including the total vibration such as the self-excited vibration and the forced vibration) obtained according to the vibration signal E, and the information of the forced vibration of the rotating shaft 102 obtained according to the first forced vibration signal D1. In the first embodiment, the display device 14 is electrically connected to the self-excited vibration bandpass filter 6, the low-pass filter 10, and the bandpass filter 12, respectively, so as to be able to obtain the self-excited vibration signal C, the vibration signal E, and the first forced vibration signal D1, respectively.

[0043] Figure 8 FIG. 1 is a diagram showing an example of display content displayed on the display device 14. Figure 8 In the example shown, the display device 14 displays (solid line) the amplitude Ca of the self-excited vibration signal C as information on the self-excited vibration of the rotating shaft 102 obtained based on the self-excited vibration signal C extracted by the self-excited vibration bandpass filter 6. The display device 14 displays (dotted line) the amplitude Ea (total amplitude) of the vibration signal E as information on the total vibration of the rotating shaft 102 obtained based on the vibration signal E extracted by the low-pass filter 10. The display device 14 displays (single-dot chain line) the amplitude D1a (rotational 1-fold amplitude: amplitude of vibration having a vibration frequency 1 times the rotation speed An) of the first forced vibration signal D1 as information on the forced vibration of the rotating shaft 102 obtained based on the first forced vibration signal D1 extracted by the bandpass filter 12.

[0044] In the first embodiment, if Figure 8 As shown in the example, the display device 14 further displays the rotation speed An of the rotating shaft 102. In addition, the display content of the display device 14 is not limited to Figure 8Although not shown in the figure, in some embodiments, the vibration monitoring device 1 further includes a MEMS sensor (MEMS: Micro Electro Mechanical Systems) for detecting the vibration of the engine connected to the supercharger 100. In addition, the display device 14 displays the amplitude of the vibration of the engine as the vibration information of the engine obtained from the output of the MEMS sensor.

[0045] (Effect) The effects of the vibration monitoring device 1 according to the first embodiment will be described. The inventors have found that if the rotation signal A that passes through the first passing range R1 set according to the natural vibration frequency Fa of the rotating shaft 102 is extracted from the rotation signal A of the rotating shaft 102, the extracted rotation signal A is equivalent to the self-excited vibration signal C that can obtain information on the self-excited vibration of the rotating shaft 102.

[0046] Fig. 9 : is a Campbell diagram of the rotating shaft 102 according to the first embodiment, wherein the vertical axis is the frequency, the horizontal axis is the rotation speed, and the oblique axis is the number of rotations. The size of the circle represents the size of the vibration amplitude. Fig. 9 , the first inclined axis 200, which is a rotation number of 1, and the second inclined axis 202, which is a rotation number of half of 1, are illustrated. If the first inclined axis 200 is observed, when the rotating shaft 102 rotates at a rotation speed An1 corresponding to the natural vibration frequency Fa (for example, when the natural vibration frequency Fa is 25 Hz, the rotation speed An1 is 1500 rpm), the amplitude of the forced vibration of the rotating shaft 102 becomes larger (circle 201 becomes larger). Furthermore, if the rotation speed An is further increased, the vibration of the forced vibration of the rotating shaft 102 becomes smaller. However, if the second inclined axis 202 is observed, when the rotating shaft 102 rotates at a speed of about twice the rotation speed An1, the amplitude of the vibration of the rotating shaft 102 becomes larger (circle 203 becomes larger). This vibration is mainly an oil film oscillation (self-excited vibration) generated by the mutual resonance between the rotating shaft 102 and the oil applied to the rotating shaft 102.

[0047] According to the first embodiment, the self-excited vibration bandpass filter 6 extracts the rotation signal A that passes through the first pass range R1 set according to the natural frequency Fa of the rotating shaft 102 as the self-excited vibration signal C. Therefore, the self-excited vibration of the rotating shaft 102 can be evaluated based on the rotation signal A of the rotating shaft 102 .

[0048] According to the first embodiment, the first passing range R1 is greater than 0.9 times the natural vibration frequency Fa of the rotating shaft 102 and less than 1.1 times the natural vibration frequency, thereby being able to suppress the acquisition of noise that does not include information on the self-excited vibration of the rotating shaft 102, and improving the accuracy of acquiring information on the self-excited vibration of the rotating shaft 102.

[0049] As described above, the vibration signal E is similar to the net actual vibration signal whose waveform is generated by the vibration of the rotating shaft 102. Therefore, by setting the cutoff frequency P according to the rotation speed An of the rotating shaft 102, the total vibration of the rotating shaft 102 can be evaluated with high accuracy. According to the first embodiment, by inputting the rotation signal A of the rotating shaft 102 and the filter command value B2, the low-pass filter 10 extracts the vibration signal E. Therefore, the total vibration of the rotating shaft 102 can be evaluated based on the rotation signal A of the rotating shaft 102.

[0050] As described above, the first forced vibration signal D1 is a signal extracted from the rotation signal A of the rotating shaft 102 by setting the center frequency Fb of the passband of the bandpass filter 12 to be the same as or substantially the same as the rotation speed An of the rotating shaft 102. And, the first forced vibration signal D1 is a signal that can evaluate the vibration (vibration having a vibration frequency of 1 times or substantially 1 times the rotation speed An) that is synchronized with the rotation of the rotating shaft 102. According to the first embodiment, the bandpass filter 12 extracts the first forced vibration signal D1 by inputting the rotation signal A of the rotating shaft 102 and the filter command value B2. Therefore, the forced vibration of the rotating shaft 102 can be evaluated based on the rotation signal A of the rotating shaft 102. In particular, the imbalance of the rotating shaft 102 of the supercharger 100 (for example, the imbalance caused by the adhesion of scale), the bending of the rotating shaft 102, or the contact between the rotating shaft 102 and the engine room can be evaluated and determined. And, the optimal maintenance of the supercharger 100 or the prevention of failure can be proposed.

[0051] According to the first embodiment, the display device 14 simultaneously displays the amplitude Ca of the self-excited vibration signal C, the amplitude Ea of the vibration signal E, and the amplitude D1a of the first forced vibration signal D1. Therefore, it is possible to evaluate the self-excited vibration and the forced vibration of the rotating shaft 102 without confusing them. Furthermore, it is possible to evaluate the forced vibration of the rotating shaft 102 that is synchronized with the rotation of the rotating shaft 102.

[0052] <Second embodiment> A vibration monitoring device 1 according to a second embodiment of the present invention will be described. In the second embodiment, the vibration monitoring device 1 further includes a nonlinear forced vibration bandpass filter 16, and the filter command value output device 8 is configured to output a division filter command value B3. In the second embodiment, the same reference numerals are given to the same components as those of the first embodiment, and detailed description thereof is omitted.

[0053] (structure) Fig.10 1 is a diagram schematically showing the structure of a vibration monitoring device 1 according to a second embodiment. Fig.10 As shown, the vibration monitoring device 1 further includes a nonlinear forced vibration bandpass filter 16. Furthermore, the filter command value output device 8 is configured to output a division filter command value B3. The nonlinear forced vibration bandpass filter 16 is electrically connected to the rotation sensor 2 and the filter command value output device 8, respectively, so as to be able to obtain the output value (rotation signal A) of the rotation sensor 2 and the output value (division filter command value B3) of the filter command value output device 8.

[0054] The division filter command value B3 will be described. Fig.11 : is a schematic functional block diagram of the filter command value output device 8 involved in the second embodiment. In the second embodiment, Fig.11 As illustrated, the filter command value output device 8 also includes a division filter command value output unit 129. The division filter command value output unit 129 divides the filter command value B2 output from the filter command value output unit 128 by n (where n=1, 2, ... is a natural number), and outputs a division filter command value B3. In some embodiments, n is 2 or 3. By setting n to 2 or 3, 1 / 2 order and 1 / 3 order subharmonic vibrations can be evaluated. Specifically, vibrations caused by loosening of bolts fastening the rotating shaft 102 or the bearing, or wear caused by one end contact, etc. can be evaluated.

[0055] By inputting the rotation signal A and the division filter command value B3, the nonlinear forced vibration bandpass filter 16 outputs (extracts) a forced vibration signal (hereinafter referred to as "the second forced vibration signal D2"). The second forced vibration signal D2 is the same as the first forced vibration signal D1 and is a signal that can obtain information on the forced vibration of the rotating shaft 102.

[0056] The nonlinear forced vibration bandpass filter 16 is configured to set the nonlinear center frequency Fc according to the division filter command value B3. The nonlinear forced vibration bandpass filter 16 allows the passband signal included in the third pass range R3 including the nonlinear center frequency Fc in the rotation signal A output by the rotation sensor 2 to pass, and cuts off the non-passband signal not included in the third pass range R3. In addition, the nonlinear forced vibration bandpass filter 16 extracts the rotation signal A included in the third pass range R3 from the rotation signal A as the second forced vibration signal D2.

[0057] Fig.12 is a graph showing the amplitude-frequency characteristics of the nonlinear forced vibration bandpass filter 16. Fig.12 In the figure, the horizontal axis is the frequency expressed in a logarithmic scale and the vertical axis is the decibel value. Fig.12 In the figure, V8 represents the characteristics of the nonlinear forced vibration bandpass filter 16 when the voltage value (division filter instruction value B3) is 0.1V, V9 represents the characteristics of the nonlinear forced vibration bandpass filter 16 when the voltage value is 1V, and V10 represents the characteristics of the nonlinear forced vibration bandpass filter 16 when the voltage value is 10V.

[0058] exist Fig.12 In the example, the decibel value is equivalent to the signal strength. When the decibel value is less than 0, the second forced vibration signal D2 extracted by the nonlinear forced vibration bandpass filter 16 is attenuated. Fig.12 As shown in FIG. 1 , in each voltage value (V8 to V10), as the frequency moves away from the nonlinear center frequency Fc of the passband of the nonlinear forced vibration bandpass filter 16, the decibel value decreases, and the attenuation rate of the second forced vibration signal D2 increases. The nonlinear center frequency Fc is set according to the division filter command value B3 (a value corresponding to the rotation speed An) output by the filter command value output device 8. Specifically, the nonlinear center frequency Fc is set to be equal to the counter unit 124 (reference number) output by the filter command value output device 8. Fig.11 ) is consistent or approximately consistent with the rotation speed An of the rotating shaft 102 counted. For example, the nonlinear forced vibration bandpass filter 16 can attenuate the second forced vibration signal D2 according to the division filter instruction value B3 to satisfy 0.8C / n≤Fc≤1.2C / n. Moreover, in a case where the rotation speed An of the rotating shaft 102 is proportional to the division filter instruction value B3, the nonlinear center frequency Fc can be set in a manner that the division filter instruction value B3 is proportional to the nonlinear center frequency Fc. Furthermore, the upper and lower limits of the passband of the nonlinear forced vibration bandpass filter 16 are set on both sides of the nonlinear center frequency Fc according to the division filter instruction value B3.

[0059] Fig.13 FIG. 1 is a diagram showing an example of display content displayed on the display device 14. Fig.13 In the example shown, the display device 14 includes Figure 8 In addition to the illustrated display contents, the amplitude D2 a of the second forced vibration signal D2 is also displayed (solid line) as information on the forced vibration of the rotating shaft 102 obtained based on the second forced vibration signal D2 extracted by the nonlinear forced vibration bandpass filter 16 .

[0060] (Effect) The effects of the vibration monitoring device 1 according to the second embodiment will be described. The inventors have found that if the nonlinear center frequency Fc is set according to the division filter command value B3, and the rotation signal A that passes through the third passing range R3 including the nonlinear center frequency Fc is extracted from the rotation signal A of the rotating shaft 102, the information of the nonlinear forced vibration of the rotating shaft 102 can be obtained from the extracted rotation signal A. Specifically, the information of the subharmonic resonance caused by the looseness of the bearing part of the bearing rotating shaft 102 due to poor assembly or the looseness of the coupling part of the rotating shaft 102 can be obtained.

[0061] According to the second embodiment, the nonlinear forced vibration bandpass filter 16 extracts the rotation signal A that passes through the third pass range R3 including the nonlinear center frequency Fc set according to the division filter command value B3 as the second forced vibration signal D2. Therefore, the nonlinear forced vibration of the rotating shaft 102 can also be evaluated based on the rotation signal A of the rotating shaft 102.

[0062] According to the second embodiment, the display device 14 simultaneously displays the amplitude Ca of the self-excited vibration signal C, the amplitude Ea of the vibration signal E, the amplitude D1a of the first forced vibration signal D1, and the amplitude D2a of the second forced vibration signal D2. Therefore, the overall (total amplitude) of the forced vibration of the rotating shaft 102, the forced vibration synchronized with the rotation of the rotating shaft 102, and the nonlinear forced vibration of the rotating shaft 102 can be evaluated without being confused with each other.

[0063] <Third embodiment> A vibration monitoring device 1 according to a third embodiment of the present invention will be described. In the third embodiment, the output device 4 and the self-excited vibration bandpass filter 6 are removed from the second embodiment. That is, the structure is such that the nonlinear forced vibration of the rotating shaft 102 can be evaluated, although the self-excited vibration of the rotating shaft 102 cannot be evaluated.

[0064] (structure) Fig.14 1 is a diagram schematically showing the structure of a vibration monitoring device 1 according to a third embodiment. Fig.14As shown, the vibration monitoring device 1 includes a rotation sensor 2, a filter command value output device 8, and a nonlinear forced vibration bandpass filter 16. In addition, in the third embodiment, the vibration monitoring device 1 further includes a low-pass filter 10, a bandpass filter 12, and a display device 14. The rotation sensor 2, the filter command value output device 8, the nonlinear forced vibration bandpass filter 16, the low-pass filter 10, the bandpass filter 12, and the display device 14 involved in the third embodiment are respectively the same as those described in the second embodiment, and are marked with the same reference symbols as the second embodiment, and their detailed description is omitted.

[0065] (Effect) According to the third embodiment, the nonlinear forced vibration bandpass filter 16 extracts the rotation signal A that passes through the third pass range R3 including the nonlinear center frequency Fc set according to the division filter command value B3 as the second forced vibration signal D2. Therefore, the nonlinear forced vibration of the rotating shaft 102 can be evaluated based on the rotation signal A of the rotating shaft 102. And, according to the third embodiment, the vibration monitoring device 1 further includes the low-pass filter 10, the bandpass filter 12 and the display device 14, so that the overall (total amplitude) of the forced vibration of the rotating shaft 102, the forced vibration synchronized with the rotation of the rotating shaft 102, and the nonlinear forced vibration of the rotating shaft 102 can be evaluated without being confused with each other.

[0066] <Vibration monitoring method> Fig.15 FIG. 1 is a flow chart of a vibration monitoring method according to an embodiment of the present invention. Fig.15 As illustrated, the vibration monitoring method includes a rotation signal output step S1 , a natural frequency filter command value output step S2 , and a self-excited vibration signal extraction step S3 .

[0067] In the rotation signal output step S1, the rotation signal A synchronized with the rotation of the rotating shaft 102 is output. In the natural vibration frequency filter command value output step S2, the natural vibration frequency filter command value B1 calculated based on the natural vibration frequency Fa of the rotating shaft 102 is output. In the self-excited vibration signal extraction step S3, by inputting the rotation signal A and the natural vibration frequency filter command value B1, a signal of a passband included in the first pass range R1 set according to the natural vibration frequency filter command value B1 is extracted from the rotation signal A as a self-excited vibration signal C capable of obtaining information on the self-excited vibration of the rotating shaft 102. According to this method, the self-excited vibration of the rotating shaft 102 can be evaluated based on the rotation signal A of the rotating shaft 102.

[0068] exist Fig.15In the illustrated embodiment, the vibration monitoring method further includes a filter command value output step S4 , a vibration signal extraction step S5 , a first forced vibration signal extraction step S6 , and a display step S7 .

[0069] In the filter command value output step S4, the filter command value B2 corresponding to the rotation speed An of the rotating shaft 102 calculated according to the rotation signal A is output. In the vibration signal extraction step S5, by inputting the rotation signal A and the filter command value B2, a signal of a passband less than the cutoff frequency P set according to the filter command value B2 is extracted from the rotation signal A as the vibration signal E. In the first forced vibration signal extraction step S6, by inputting the rotation signal A and the filter command value B2, a signal of a passband including the center frequency Fb set according to the filter command value B2 is extracted from the rotation signal A as the first forced vibration signal D1. In the display step S7, information on the total vibration of the rotating shaft 102 obtained according to the vibration signal E, information on the forced vibration of the rotating shaft 102 obtained according to the first forced vibration signal D1, and information on the self-excited vibration of the rotating shaft 102 obtained according to the self-excited vibration signal C are simultaneously displayed. According to this method, the self-excited vibration and the forced vibration of the rotating shaft 102 can be evaluated without being confused. Furthermore, it is possible to evaluate the forced vibration of the rotating shaft 102 that is synchronized with the rotation of the rotating shaft 102 .

[0070] exist Fig.15 In the illustrated embodiment, the vibration monitoring method further includes a determination step S8. In the determination step S8, after executing the display step S7, a first division value obtained by dividing the "amplitude D1a of the first forced vibration signal D1" by the "amplitude Ea of the vibration signal E" and a second division value obtained by dividing the "amplitude Ca of the self-excited vibration signal C" by the "amplitude Ea of the vibration signal E" are calculated. And, when the first division value is greater than a specified value (for example, 0.8) or the second division value is less than a specified value (for example, 0.5), it is determined that the vibration of the rotating shaft 102 is dominated by forced vibration. In some embodiments, when the first division value is greater than a specified value (for example, 0.8) and the second division value is greater than a specified value (for example, 0.5), it is determined that the vibration of the rotating shaft 102 is dominated by forced vibration. In some embodiments, when the first division value is less than a predetermined value (eg, 0.8) and the second division value is greater than a predetermined value (eg, 0.5), it is determined that the vibration of the rotating shaft 102 is dominated by self-excited vibration.

[0071] Fig.16 FIG. 1 is a flow chart of a vibration monitoring method according to another embodiment. Fig.16 As illustrated, the vibration monitoring method includes a rotation signal output step S11 , a division filter command value output step S12 , and a second forced vibration signal extraction step S13 .

[0072] In the rotation signal output step S11, a rotation signal A synchronized with the rotation of the rotating shaft 102 is output. In the division filter command value output step S12, a division filter command value B3 is output, which is obtained by dividing the filter command value B2 corresponding to the rotation speed An of the rotating shaft 102 calculated based on the rotation signal A by n (where n=1, 2, ... is a natural number). In the second forced vibration signal extraction step S13, by inputting the rotation signal A and the division filter command value B3, a signal including a passband of the nonlinear center frequency Fc set according to the division filter command value B3 is extracted from the rotation signal A as the second forced vibration signal D2. According to this method, the nonlinear forced vibration of the rotating shaft 102 can be evaluated based on the rotation signal A of the rotating shaft 102.

[0073] exist Fig.16 In the illustrated embodiment, the vibration monitoring method further includes a filter command value output step S14 , a vibration signal extraction step S15 , a first forced vibration signal extraction step S16 , and a display step S17 .

[0074] In the filter command value output step S14, the filter command value B2 corresponding to the rotation speed An of the rotating shaft 102 calculated based on the rotation signal A is output. In the vibration signal extraction step S15, by inputting the rotation signal A and the filter command value B2, a signal of a passband less than the cutoff frequency P set according to the filter command value B2 is extracted from the rotation signal A as the vibration signal E. In the first forced vibration signal extraction step S16, by inputting the rotation signal A and the filter command value B2, a signal of a passband including the center frequency Fb set according to the filter command value B2 is extracted from the rotation signal A as the first forced vibration signal D1. In the display step S17, information on the total vibration of the rotating shaft 102 obtained based on the vibration signal E, information on the forced vibration of the rotating shaft 102 obtained based on the first forced vibration signal D1, and information on the forced vibration of the rotating shaft 102 obtained based on the second forced vibration signal D2 are simultaneously displayed. According to this method, the entire vibration (total amplitude) of the rotating shaft 102 , the forced vibration synchronized with the rotation of the rotating shaft 102 , and the nonlinear forced vibration of the rotating shaft 102 can be evaluated without being confused with each other.

[0075] exist Fig.16In the illustrated embodiment, the vibration monitoring method further includes a determination step S18. In the determination step S18, after executing the display step S17, a third division value obtained by dividing the "amplitude D1a of the first forced vibration signal D1" by the "amplitude Ea of the vibration signal E" and a fourth division value obtained by dividing the "amplitude D2a of the second forced vibration signal D2" by the "amplitude Ea of the vibration signal E" are calculated. And, when the third division value is less than a specified value (for example, 0.8) and the fourth division value is greater than a specified value (for example, 0.4), it is determined that the vibration of the rotating shaft 102 is dominated by nonlinear forced vibration. In some embodiments, when the third division value is greater than a specified value (for example, 0.8) or the fourth division value is less than a specified value (for example, 0.4), it is determined that the vibration of the rotating shaft 102 is dominated by vibration other than nonlinear forced vibration.

[0076] The contents described in the above-mentioned embodiments can be understood, for example, as follows.

[0077] [1] The vibration monitoring device (1) according to the present invention comprises: A rotation sensor (2) outputting a rotation signal (A) synchronized with the rotation of the rotation shaft (102); An output device (4) outputs a natural vibration frequency filter command value (B1) calculated based on the natural vibration frequency (Fa) of the rotating shaft; and The self-excited vibration bandpass filter (6) extracts a passband signal included in a pass range (R1) set according to the natural vibration frequency filter command value from the rotation signal by inputting the rotation signal and the natural vibration frequency filter command value, as a self-excited vibration signal (C) capable of obtaining information on the self-excited vibration of the rotating shaft.

[0078] According to the inventors, if a rotation signal passing through a passband set according to the natural vibration frequency of the rotating shaft is extracted from the rotation signal of the rotating shaft, the extracted rotation signal is equivalent to a self-excited vibration signal that can obtain information on the self-excited vibration of the rotating shaft. According to the structure described in [1] above, the self-excited vibration bandpass filter extracts the rotation signal passing through the passband set according to the natural vibration frequency of the rotating shaft as the self-excited vibration signal. Therefore, the self-excited vibration of the rotating shaft can be evaluated based on the rotation signal of the rotating shaft.

[0079] [2] In some embodiments, in the structure described in [1] above, it also comprises: a filter command value output device (8) for outputting a divided filter command value (B3) obtained by dividing a filter command value (B2) corresponding to the rotation speed (An) of the rotating shaft calculated based on the rotation signal by n (where n=1, 2, ... is a natural number); and A nonlinear forced vibration bandpass filter (16) extracts a signal of a passband including a nonlinear center frequency (Fc) set according to the division filter command value from the rotation signal by inputting the rotation signal and the division filter command value, as a forced vibration signal (D3) capable of obtaining information on the forced vibration of the rotating shaft.

[0080] According to the present inventors, if the nonlinear center frequency is set according to a division filter command value obtained by dividing a filter command value corresponding to the rotation speed of a rotating shaft by n, and a rotation signal passing through a passband including the nonlinear center frequency is extracted from the rotation signal of the rotating shaft, then the extracted rotation signal is equivalent to a forced vibration signal capable of obtaining information on the nonlinear forced vibration of the rotating shaft. According to the structure described in [2] above, the nonlinear forced vibration bandpass filter extracts the rotation signal passing through a passband including the nonlinear center frequency set according to the division filter command value as a forced vibration signal. Therefore, the nonlinear forced vibration can also be evaluated based on the rotation signal of the rotating shaft.

[0081] [3] In some embodiments, in the structure described in [1] above, it further comprises: a filter command value output device (8) for outputting a filter command value (B2) corresponding to the rotation speed (An) of the rotating shaft calculated based on the rotation signal; A low-pass filter (10) which, by inputting the rotation signal and the filter command value, extracts from the rotation signal a signal having a passband smaller than a cutoff frequency (P) set according to the filter command value as a vibration signal (E) capable of obtaining information on the vibration of the rotating shaft; a bandpass filter (12) which, by inputting the rotation signal and the filter command value, extracts from the rotation signal a signal of a passband including a center frequency (Fb) set according to the filter command value as a forced vibration signal (D2) capable of obtaining information on the forced vibration of the rotating shaft; and The display device (14) simultaneously displays the vibration information of the rotating shaft obtained based on the vibration signal extracted by the low-pass filter, the forced vibration information of the rotating shaft obtained based on the forced vibration signal extracted by the band-pass filter, and the self-excited vibration information of the rotating shaft obtained based on the self-excited vibration signal extracted by the self-excited vibration band-pass filter.

[0082] According to the structure described in [3] above, the self-excited vibration and forced vibration of the rotating shaft can be evaluated without being confused. In addition, the forced vibration of the rotating shaft extracted by the bandpass filter (i.e., the forced vibration synchronized with the rotation of the rotating shaft) can be evaluated.

[0083] [4] In some embodiments, in the structure described in [2] above, The filter command value output device is configured to further output the filter command value, The vibration monitoring device further comprises: A low-pass filter (10) which, by inputting the rotation signal and the filter command value, extracts from the rotation signal a signal having a passband smaller than a cutoff frequency (P) set according to the filter command value as a vibration signal (E) capable of obtaining information on the vibration of the rotating shaft; a bandpass filter (12) which, by inputting the rotation signal and the filter command value, extracts a signal of a passband including a center frequency (Fb) set according to the filter command value from the rotation signal as the forced vibration signal (D2); and The display device (14) simultaneously displays the vibration information of the rotating shaft obtained based on the vibration signal extracted by the low-pass filter, the forced vibration information of the rotating shaft obtained based on the forced vibration signal extracted by the band-pass filter, and the forced vibration information of the rotating shaft obtained based on the forced vibration signal extracted by the nonlinear forced vibration band-pass filter.

[0084] According to the structure described in [4] above, the forced vibration of the rotating shaft extracted by the low-pass filter, the forced vibration of the rotating shaft extracted by the band-pass filter, and the forced vibration of the rotating shaft extracted by the nonlinear forced vibration band-pass filter can be evaluated without being confused with each other.

[0085] [5] In some embodiments, in the structure described in any one of [1] to [4] above, The passing range is greater than or equal to 0.9 times the natural vibration frequency and less than or equal to 1.1 times the natural vibration frequency.

[0086] According to the configuration described in [5] above, it is possible to suppress the acquisition of noise that does not include information on the self-excited vibration of the rotating shaft, and to improve the accuracy of acquiring information on the self-excited vibration of the rotating shaft.

[0087] [6] The vibration monitoring device (1) according to the present invention comprises: A rotation sensor (2) outputting a rotation signal (A) synchronized with the rotation of the rotation shaft (102); a filter command value output device (8) for outputting a divided filter command value (B3) obtained by dividing a filter command value (B2) corresponding to the rotation speed (An) of the rotating shaft calculated based on the rotation signal by n (where n=1, 2, ... is a natural number); and A nonlinear forced vibration bandpass filter (16) extracts a signal of a passband including a nonlinear center frequency (Fc) set according to the division filter command value from the rotation signal by inputting the rotation signal and the division filter command value, as a forced vibration signal (D3) capable of obtaining information on the forced vibration of the rotating shaft.

[0088] According to the present inventors, if the nonlinear center frequency is set according to a division filter command value obtained by dividing a filter command value corresponding to the rotation speed of a rotating shaft by n, and a rotation signal passing through a passband including the nonlinear center frequency is extracted from the rotation signal of the rotating shaft, then the extracted rotation signal is equivalent to a forced vibration signal capable of obtaining information on the nonlinear forced vibration of the rotating shaft. According to the structure described in [6] above, the nonlinear forced vibration bandpass filter extracts the rotation signal passing through a passband including the nonlinear center frequency set according to the division filter command value as a forced vibration signal. Therefore, the nonlinear forced vibration can be evaluated based on the rotation signal of the rotating shaft.

[0089] [7] The supercharger (100) according to the present invention comprises: The vibration monitoring device (1) as described in any one of [1] to [6] above; A compressor (104) is disposed at one end of the rotating shaft; and The turbine (106) is arranged at the other end of the rotating shaft.

[0090] According to the structure described in [7] above, it is possible to provide a supercharger capable of evaluating the self-excited vibration or nonlinear forced vibration of the rotating shaft of the supercharger based on the rotation signal of the rotating shaft of the supercharger.

[0091] [8] The vibration monitoring method of the present invention comprises the following steps: Step (S1), outputting a rotation signal synchronized with the rotation of the rotation shaft; Step (S2), outputting a natural vibration frequency filter command value calculated according to the natural vibration frequency of the rotating shaft; and Step (S3), by inputting the rotation signal and the natural vibration frequency filter command value, extracting from the rotation signal a signal of a passband contained in a pass range set according to the natural vibration frequency filter command value as a self-excited vibration signal capable of obtaining information on the self-excited vibration of the rotating shaft.

[0092] According to the method described in [8] above, since the rotation signal of the rotating shaft that passes through the passband set according to the natural vibration frequency of the rotating shaft is extracted as the self-excited vibration signal, the self-excited vibration of the rotating shaft can be evaluated based on the rotation signal of the rotating shaft.

[0093] [9] The vibration monitoring method of the present invention comprises the following steps: Step (S11), outputting a rotation signal synchronized with the rotation of the rotating shaft; Step (S12), outputting a divided filter command value obtained by dividing the filter command value corresponding to the rotation speed of the rotating shaft calculated based on the rotation signal by n, wherein n=1, 2, ... is a natural number; and Step (S13), by inputting the rotation signal and the division filter instruction value, extracting from the rotation signal a signal containing a passband of a nonlinear center frequency set according to the division filter instruction value as a forced vibration signal capable of obtaining information on the forced vibration of the rotating shaft.

[0094] According to the method described in [9] above, since the rotation signal of the rotating shaft passing through the passband including the nonlinear center frequency set according to the division filter command value is extracted as the forced vibration signal, the nonlinear forced vibration can be evaluated based on the rotation signal of the rotating shaft. Explanation of symbols

[0095] 1-vibration monitoring device, 2-rotation sensor, 4-output device, 6-self-excited vibration bandpass filter, 8-filter command value output device, 10-low-pass filter, 12-bandpass filter, 14-display device, 16-nonlinear forced vibration bandpass filter, 100-supercharger, 102-rotation shaft, 104-compressor, 106-turbine, 122-frequency division part, 124-counter part, 126-display part, 128-filter command value output part, 129-division filter command value output part, 200-first oblique axis, 202-second oblique axis, A-rotation signal, A n-rotation speed, Ap-rotation pulse signal, B1-natural vibration frequency filter instruction value, B2-filter instruction value, B3-division filter instruction value, C-self-excited vibration signal, D1-1st forced vibration signal, D2-2nd forced vibration signal, E-vibration signal, Fa-natural vibration frequency, Fb-center frequency, Fc-nonlinear center frequency, P-cut-off frequency, R1-1st pass range, R2-2nd pass range, R3-3rd pass range, S1-rotation signal output step, S2-natural vibration frequency filter instruction value output step, S3-self-excited vibration signal extraction step, S11-rotation signal output step, S12-division filter instruction value output step, S13-2nd forced vibration signal extraction step.

Claims

1. A vibration monitoring device, comprising: A rotation sensor outputs a rotation signal synchronized with the rotation of the rotation shaft; an output device that outputs a natural vibration frequency filter command value calculated based on the natural vibration frequency of the rotating shaft; and The self-excited vibration bandpass filter, by inputting the rotation signal and the natural vibration frequency filter command value, extracts from the rotation signal a signal of a passband contained in a pass range set according to the natural vibration frequency filter command value as a self-excited vibration signal capable of obtaining information on the self-excited vibration of the rotating shaft.

2. The vibration monitoring device according to claim 1, further comprising: The filter command value output device outputs a divided filter command value obtained by dividing the filter command value corresponding to the rotation speed of the rotating shaft calculated based on the rotation signal by n, wherein n=1, 2, ... are natural numbers; and The nonlinear forced vibration bandpass filter extracts a signal of a passband including a nonlinear center frequency set according to the division filter command value from the rotation signal by inputting the rotation signal and the division filter command value, as a forced vibration signal capable of obtaining information on the forced vibration of the rotating shaft.

3. The vibration monitoring device according to claim 1, further comprising: a filter command value output device that outputs a filter command value corresponding to the rotation speed of the rotating shaft calculated based on the rotation signal; a low-pass filter that extracts a signal having a passband smaller than a cutoff frequency set according to the filter command value from the rotation signal by inputting the rotation signal and the filter command value as a vibration signal capable of obtaining information on the vibration of the rotating shaft; a bandpass filter which, by inputting the rotation signal and the filter command value, extracts from the rotation signal a signal of a passband including a center frequency set according to the filter command value as a forced vibration signal capable of obtaining information on the forced vibration of the rotating shaft; and The display device simultaneously displays the vibration information of the rotating shaft obtained based on the vibration signal extracted by the low-pass filter, the forced vibration information of the rotating shaft obtained based on the forced vibration signal extracted by the band-pass filter, and the self-excited vibration information of the rotating shaft obtained based on the self-excited vibration signal extracted by the self-excited vibration band-pass filter.

4. The vibration monitoring device according to claim 2, wherein: The filter command value output device is configured to further output the filter command value, The vibration monitoring device further comprises: a low-pass filter that extracts a signal having a passband smaller than a cutoff frequency set according to the filter command value from the rotation signal by inputting the rotation signal and the filter command value as a vibration signal capable of obtaining information on the vibration of the rotating shaft; a bandpass filter which extracts a signal of a passband including a center frequency set according to the filter command value from the rotation signal by inputting the rotation signal and the filter command value as the forced vibration signal; and The display device simultaneously displays the vibration information of the rotating shaft obtained based on the vibration signal extracted by the low-pass filter, the forced vibration information of the rotating shaft obtained based on the forced vibration signal extracted by the band-pass filter, and the forced vibration information of the rotating shaft obtained based on the forced vibration signal extracted by the nonlinear forced vibration band-pass filter.

5. The vibration monitoring device according to any one of claims 1 to 4, wherein: The passing range is greater than or equal to 0.9 times the natural vibration frequency and less than or equal to 1.1 times the natural vibration frequency.

6. A vibration monitoring device comprising: A rotation sensor outputs a rotation signal synchronized with the rotation of the rotation shaft; The filter command value output device outputs a divided filter command value obtained by dividing the filter command value corresponding to the rotation speed of the rotating shaft calculated based on the rotation signal by n, wherein n=1, 2, ... are natural numbers; and The nonlinear forced vibration bandpass filter extracts a signal of a passband including a nonlinear center frequency set according to the division filter command value from the rotation signal by inputting the rotation signal and the division filter command value, as a forced vibration signal capable of obtaining information on the forced vibration of the rotating shaft.

7. A supercharger comprising: The vibration monitoring device according to any one of claims 1 to 4 and 6; A compressor is disposed at one end of the rotating shaft; and The turbine is arranged at the other end of the rotating shaft.

8. A vibration monitoring method comprising the following steps: outputting a rotation signal synchronized with the rotation of the rotating shaft; outputting a natural frequency filter command value calculated based on the natural frequency of the rotating shaft; and By inputting the rotation signal and the natural vibration frequency filter command value, a passband signal included in a pass range set according to the natural vibration frequency filter command value is extracted from the rotation signal as a self-excited vibration signal capable of obtaining information on the self-excited vibration of the rotating shaft.

9. A vibration monitoring method comprising the following steps: outputting a rotation signal synchronized with the rotation of the rotating shaft; Outputting a divided filter command value obtained by dividing a filter command value corresponding to the rotation speed of the rotating shaft calculated based on the rotation signal by n, wherein n=1, 2, ... are natural numbers; and By inputting the rotation signal and the division filter command value, a signal including a passband of a nonlinear center frequency set according to the division filter command value is extracted from the rotation signal as a forced vibration signal capable of obtaining information on the forced vibration of the rotating shaft.

Images