Equipment abnormal vibration measuring device, abnormal vibration measuring method, and abnormal vibration measuring program

Abstract

To measure abnormal vibration using time-of-arrival of a vibration even for equipment with a complex shape.SOLUTION: An abnormal vibration measurement device comprises a characteristic calculation unit and a vibration source estimation unit. The characteristic calculation unit calculates a first vibration transmission speed based on a first distance from a first vibration sensor to an exciter and a first vibration transmission time until an excited wave reaches the first vibration sensor when a vibration transmission path is excited by the exciter and a second vibration transmission speed based on a second distance from a second vibration sensor to the exciter and a second vibration transmission time until the excited wave reaches the second vibration sensor, as a vibration transmission speed characteristic of equipment. The vibration source estimation unit estimates a location where the vibration occurs on the basis of a time difference in the vibration transmission time that the vibration reaches the first vibration sensor and the second vibration sensor when the vibration occurred in the equipment and the vibration transmission speed characteristic.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The embodiments relate to an abnormal vibration measuring device, an abnormal vibration measuring method, and an abnormal vibration measuring program for equipment. [Background technology]

[0002] Measuring abnormal vibrations in equipment that has motors or the like is sometimes used as a method for measuring failures. One method known for measuring abnormal vibrations and other types of vibration is to identify the location of the vibration from the vibration transmission time from the vibration source to the vibration sensor. In the case of equipment with a complex shape, the vibration transmission speed may differ depending on the location of the vibration transmission path. When the vibration transmission speed differs depending on the location, an error will occur if you try to identify the location of the vibration simply from the vibration transmission time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-219377 A Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments provide an abnormal vibration measuring device, an abnormal vibration measuring method, and an abnormal vibration measuring program for equipment that can measure abnormal vibrations using the vibration arrival time even in equipment with a complex shape. [Means for solving the problem]

[0005] An abnormal vibration measuring device according to one aspect includes a characteristic calculation unit and a vibration source estimation unit. The characteristic calculation unit calculates, as vibration transmission velocity characteristics of the equipment, a first vibration transmission velocity based on a first distance along the vibration transmission path from the first vibration sensor to the vibration exciter and a first vibration transmission time until the excitation wave is transmitted from the vibration exciter to the first vibration sensor, and a second vibration transmission velocity based on a second distance along the vibration transmission path from the second vibration sensor to the vibration exciter and a second vibration transmission time until the excitation wave is transmitted from the vibration exciter to the second vibration sensor, when a predetermined position of a vibration transmission path is excited by the vibration exciter. The vibration source estimation unit estimates a position where the vibration occurred in the equipment based on a time difference between the vibration transmission times until the vibration is transmitted to each of the first vibration sensor and the second vibration sensor, when vibration occurs in the equipment, and the vibration transmission velocity characteristics. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a device that is a measurement target for abnormal vibration. [Diagram 2] FIG. 2 is a diagram illustrating a configuration of an example of the control device. [Diagram 3] FIG. 3 is a flowchart showing an example of a measurement process of vibration transmission velocity characteristics. [Figure 4] FIG. 4 is a diagram showing an outline of a measurement process for vibration transmission velocity characteristics. [Diagram 5] FIG. 5 is a diagram showing an example of a vibration waveform output from a vibrator, a vibration waveform detected by the vibration sensor 50a, and a vibration waveform detected by the vibration sensor 50b. [Figure 6] FIG. 6 is a diagram showing an example of vibration transmission speed characteristics calculated based on the settings of the vibration transmission path in FIG. [Figure 7] FIG. 7 is a flowchart illustrating an example of a vibration source estimation process. [Figure 8] FIG. 8 is a diagram for explaining the process of estimating the vibration source. [Figure 9]FIG. 9 is a diagram showing an example of vibration transmission velocity characteristics when the number of sections is n. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of a device to be measured for abnormal vibration. The device 1 has a motor 10, a gear box 20, and a driven object 30. The motor 10 and the gear box 20 are connected via a coupling 40. In addition, a vibration sensor 50a is attached to the housing surface of the gear box 20, and a vibration sensor 50b is attached to the housing surface of the motor 10. The vibration sensors 50a and 50b are electrically connected to a control device 60.

[0008] The motor 10 is a device that converts electrical energy into mechanical energy. The motor 10 has, for example, a rotor 11, a stator 12, and bearings 13a and 13b. The rotor 11 has a rotating shaft and is an element that rotates around the rotating shaft. The rotating shaft of the rotor 11 is connected to the coupling 40. The stator 12 is, for example, formed around the rotor 11 and is an element that generates a force for rotating the rotating shaft of the rotor 11 by interacting with the rotor 11. The interaction between the rotor 11 and the stator 12 is, for example, a magnetic interaction. The bearings 13a and 13b support the rotating shaft of the rotor 11 with low friction force. Here, when the tip of the rotating shaft of the rotor 11 is the end connected to the coupling 40 and the base end of the rotating shaft of the rotor 11 is the end opposite to the tip, the bearing 13a is arranged to support the tip side of the rotating shaft of the rotor 11, and the bearing 13b is arranged to support the base end side of the rotating shaft of the rotor 11.

[0009] Here, in the embodiment, the configuration of the motor 10 is not limited to a specific configuration. For example, a permanent magnet or an electromagnet may be used as a configuration for causing magnetic interaction.

[0010] The gear box 20 is a box that houses at least one gear. In the embodiment, the gear box 20 has, for example, two gears 21a and 21b and bearings 22a, 22b, 22c, and 22d. The gear 21a is a gear having a rotating shaft. The rotating shaft of the gear 21a is connected to the rotating shaft of the rotor 11 of the motor 10 via the coupling 40. In other words, the gear 21a is configured to rotate according to the rotation of the rotating shaft of the rotor 11. The gear 21b is a gear having a rotating shaft like the gear 21a. The rotating shaft of the gear 21b is connected to the driven object 30. In addition, the gear 21b is arranged to mesh with the gear 21a. In other words, the gear 21b is configured to rotate according to the rotation of the gear 21a. The bearings 22a and 22b support the rotating shaft of the gear 21a with low friction force. The bearings 22c and 22d support the rotating shaft of the gear 21b with low friction. Here, when the base end of the rotating shaft of the gear 21a is the end connected to the coupling 40 and the tip of the rotating shaft of the gear 21a is the end opposite to the base end, the bearing 22a is arranged to support the tip side of the rotating shaft of the gear 21a, and the bearing 22b is arranged to support the base end side of the rotating shaft of the gear 21a. When the tip of the rotating shaft of the gear 21b is the end connected to the driven object 30 and the base end of the rotating shaft of the gear 21b is the end opposite to the tip, the bearing 22c is arranged to support the tip side of the rotating shaft of the gear 21b, and the bearing 22d is arranged to support the base end side of the rotating shaft of the gear 21b.

[0011] Here, in the embodiment, the configuration of the gear box 20 is not limited to a specific configuration. For example, the number of gears inside the gear box 20 is not limited to two. Also, in FIG. 1, the gears 21a and 21b are shown to have the same size. However, the gears 21a and 21b may have different sizes.

[0012] The driven object 30 is an object that is driven by the rotational force of the motor 10. In the embodiment, the rotational force of the motor 10 is transmitted to the driven object 30 via the gear 21a and the gear 21b. The driven object 30 may be any object that is driven by the motor 10.

[0013] The coupling 40 connects the rotating shaft of the rotor 11 and the rotating shaft of the gear 21a of the gear box 20. The coupling 40 is configured to absorb the misalignment between the rotating shaft of the rotor 11 and the rotating shaft of the gear 21a of the gear box 20 and to connect the two.

[0014] In the embodiment, at least two vibration sensors 50a, 50b are attached to the device 1 in order to identify abnormal vibration in the device 1. The vibration sensors 50a, 50b may be any sensor capable of detecting vibration, such as an acceleration sensor or an angular velocity sensor. The vibration sensors 50a, 50b are attached to a position adjacent to the gear 21b on the housing surface of the gear box 20 and a position adjacent to the bearing 13b on the housing surface of the motor 10, as shown in FIG. 1, for example. The vibration sensors 50a, 50b are not limited to these positions. However, the vibration sensors 50a, 50b must be attached to a position capable of detecting vibrations that are expected to occur in the device 1. The vibration sensors 50a, 50b are connected to the control device 60 by wired connection, for example. However, if the vibration sensors 50a, 50b are equipped with wireless transmission devices, the vibration sensors 50a, 50b may be connected to the control device 60 by wireless connection.

[0015] The control device 60 processes the output signals of the vibration sensors 50a and 50b. The control device 60 also controls the vibration exciter, which will be described later. Fig. 2 is a diagram showing an example of the configuration of the control device 60. The control device 60 is a computer having, for example, a processor 61, a ROM 62, a RAM 63, a storage 64, an input interface 65, and an output interface 66.

[0016] The processor 61 is a hardware processor such as a CPU, and controls the overall operation of the control device 60. The processor 61 executes processing in accordance with a program 641 recorded in the storage 64, and thereby can operate as a noise removal unit 611, a characteristic calculation unit 612, a vibration source estimation unit 613, and a vibration control unit 614.

[0017] The noise removal unit 611 removes noise in the output signals of the vibration sensors 50a and 50b by band-pass filtering. The noise is noise generated by an inverter that drives the motor 10, for example, and is constantly superimposed on the output signals of the vibration sensors 50a and 50b.

[0018] Based on the output signals of the vibration sensors 50a and 50b, the characteristic calculation unit 612 calculates, for each section, the vibration transmission speed characteristic of the vibration generated on a vibration transmission path that is set in advance in the device 1. The vibration transmission path is a vibration transmission path that starts at the attachment position of the vibration sensor 50a and ends at the attachment position of the vibration sensor 50b, and includes the position of a vibration source where abnormal vibration is expected to occur in the device 1. The operation of the characteristic calculation unit 612 will be described in detail later.

[0019] The vibration source estimation unit 613 estimates the position of the vibration source on the vibration transmission path based on the output signals of the vibration sensors 50a and 50b and the vibration transmission velocity characteristic calculated by the characteristic calculation unit 612. The operation of the vibration source estimation unit 613 will be described in detail later.

[0020] The vibration control unit 614 controls the operation of the vibration exciter, which will be described later. For example, the vibration control unit 614 starts and ends the vibration by the vibration exciter. The vibration control unit 614 also selects an excitation wave used for the vibration by the vibration exciter.

[0021] Here, the noise removal unit 611, the characteristic calculation unit 612, the vibration source estimation unit 613, and the vibration control unit 614 may be configured by dedicated hardware for performing each operation. For example, the noise removal unit 611 may be configured as a band-pass filter circuit.

[0022] The ROM 62 is a non-volatile memory that stores basic programs such as a startup program for the control device 60 and parameters used for various processes.

[0023] The RAM 63 is a volatile memory and operates as a working memory for temporarily storing, for example, data input to the control device 60, data generated in the control device 60, and the like.

[0024] The storage 64 is a storage such as a hard disk drive (HDD) or a solid state drive (SSD). The storage 64 stores a program 641 and vibration transmission velocity characteristic data 642. The program 641 is a program for causing the processor 61 to execute processes as the noise removal unit 611, the characteristic calculation unit 612, the vibration source estimation unit 613, and the vibration control unit 614. The vibration transmission velocity characteristic data 642 is data of a graph or table representing a vibration transmission velocity characteristic calculated by the operation of the characteristic calculation unit 612. The vibration transmission velocity characteristic data 642 will be described in detail later. Note that the vibration transmission velocity characteristic data 642 does not necessarily have to be stored in the storage 64 of the control device 60. The vibration transmission velocity characteristic data 642 may be stored in a storage provided separately from the control device 60. In this case, the control device 60 acquires the vibration transmission velocity characteristic data 642 from this separate storage as necessary.

[0025] The input interface 65 is an interface through which an operator of the device 1 makes various inputs to the control device 60. The input interface 65 may include a touch panel, a keyboard, a mouse, and the like.

[0026] The output interface 66 is an interface for outputting the results of processing by the processor 61. The output interface 66 may include a display, a printer, and the like.

[0027] Next, the vibration detection operation in the device 1 will be described. First, a method for measuring the vibration transmission velocity characteristic will be described. FIG. 3 is a flowchart showing an example of the measurement process of the vibration transmission velocity characteristic. FIG. 4 is a diagram showing an outline of the measurement process of the vibration transmission velocity characteristic. The measurement process of the vibration transmission velocity characteristic is performed, for example, when the device 1 is manufactured, or before the device 1 is actually operated, such as after a predetermined period of time such as one week or one year has elapsed.

[0028] In step S1, the processor 61 of the control device 60 sets a vibration transmission path in the device 1. An example of the setting of the vibration transmission path will be described. As described above, the vibration transmission path is a transmission path of vibration that starts from the mounting position of the vibration sensor 50a, ends at the mounting position of the vibration sensor 50b, and includes the position of a vibration source where abnormal vibration is expected to occur in the device 1. For example, in the case of a device having a configuration in which a motor and a gear box are connected via a coupling as shown in FIG. 1, which is commonly used in industrial equipment, failures often occur at points that have structural contact parts such as the meshing parts of bearings and gears. In failures that occur at these points that have contact parts, the contact parts deteriorate due to wear over time, and abnormal vibrations may occur due to the deterioration of the contact parts. Therefore, the vibration transmission path can be set, for example, with the meshing part P1 of the gears 21a and 21b as a base point, as shown in FIG. 4. When vibration occurs at the meshing portion P1 of the gear 21a and the gear 21b, the vibration is usually transmitted through the gear 21b to reach the vibration sensor 50a, and also transmitted through the gear 21a and the rotor 11 of the motor 10 to reach the vibration sensor 50b. Such a vibration transmission path is the vibration transmission path R shown in FIG. 4. The vibration transmission path R can be set by, for example, an operator operating the input interface 65 of the control device 60. In this case, for example, the control device 60 displays a schematic diagram of the device 1 as shown in FIG. 1 on the display, and the operator may set the vibration transmission path R on this schematic diagram. In response to the setting by the operator, the processor 61 sets the vibration transmission path R. The processor 61 also calculates the entire distance L of the vibration transmission path R. The distance L is the distance along the vibration transmission path R from the position of the vibration sensor 50a to the position of the vibration sensor 50b. The processor 61 stores the data of the vibration transmission path R and the data of the distance L in, for example, the storage 64.

[0029] Here, the vibration transmission path R may be set according to, for example, the results of a vibration transmission simulation. The vibration transmission simulation may be performed based on a finite element method (FEM) model of the device 1 created assuming that the internal structure of the device 1 is known. In addition, although one vibration transmission path R is set in Fig. 4, multiple vibration transmission paths may be set depending on the structure of the device 1. When multiple vibration transmission paths are set, it is desirable that the overall distances of the respective vibration transmission paths are different.

[0030] In step S2, the processor 61 divides the vibration transmission path R into a plurality of sections. The sections are divided, for example, according to the mounting position of the vibration exciter and the mounting position of the vibration sensor. The vibration exciter 70 is attached to a position on the vibration transmission path R where the vibration exciter 70 can be attached. For example, in FIG. 4, the vibration exciter 70 is attached on the housing surface of the gear box 20 near the rotation axis of the gear 21a. In this case, the vibration transmission path R is divided into at least a section R1 from the vibration sensor 50a to the position P2 of the vibration exciter 70, and a section R2 from the position P2 of the vibration exciter 70 to the vibration sensor 50b. The sections can be set, for example, by the operator operating the input interface 65 of the control device 60. In this case, for example, the control device 60 displays a schematic diagram of the device 1 as shown in FIG. 1 on the display, and the operator may specify the mounting position P2 of the vibration exciter 70 on the schematic diagram. In response to this, the processor 61 divides the vibration transmission path R into a section R1 and a section R2. The processor 61 also calculates a distance L1 in section R1 and a distance L2 in section R2. The distance L1 is the distance along the vibration transmission path R from the position of the vibration sensor 50a to the position P2 of the vibrator 70. The distance L2 is the distance along the vibration transmission path R from the position of the vibration sensor 50b to the position P2 of the vibrator 70. The processor 61 stores data on sections R1 and R2 and data on distances L1 and L2 in the storage 64, for example.

[0031] Here, when the operator specifies the installation position of the vibration exciter 70, if the specified position is one where the vibration exciter 70 cannot be installed, the processor 61 may issue a warning to the operator.

[0032] In addition, rather than an operator inputting the position of the vibrator 70 into the control device 60, if a position sensor or the like is attached to the vibrator 70, when the vibrator 70 is actually attached to the equipment 1, information on the installation position of the vibrator 70 may be input, for example, from the vibrator 70 to the control device 60.

[0033] In step S3, the processor 61 outputs a control signal to the vibrator 70 to vibrate the mounting portion by the vibrator 70. Any of an impact waveform, a sine waveform, a frequency sweep waveform, and a random waveform may be used as the vibration waveform output from the vibrator 70. When the vibrator 70 performs vibration, signals representing the vibration waveforms are output from each of the vibration sensors 50a and 50b to the control device 60. FIG. 5 is a diagram showing an example of a vibration waveform W1 output from the vibrator 70, a vibration waveform W2 detected by the vibration sensor 50a, and a vibration waveform W3 detected by the vibration sensor 50b. The vibration waveform W1 corresponds to the waveform of the control signal output from the control device 60 to the vibrator 70. The processor 61 obtains the vibration waveforms W2 and W3 by removing noise in the output signal of the vibration sensor 50a and the output signal of the vibration sensor 50b.

[0034] In step S4, the processor 61 calculates the vibration transmission time, which is the time required for vibration transmission in each section, by comparing the vibration waveform output from the vibrator 70, i.e., the waveform of the control signal, with the waveforms of the output signals from the vibration sensors 50a and 50b. As a method for calculating the vibration transmission time, for example, a method for detecting the rising edge of a waveform may be used. Specifically, as shown in FIG. 5, the processor 61 calculates the time difference between the rising edge of the vibration waveform W1 output from the vibrator 70 and the rising edge of the vibration waveform W2 detected by the vibration sensor 50a as the vibration transmission time T1. Similarly, as shown in FIG. 5, the processor 61 calculates the time difference between the rising edge of the vibration waveform W1 output from the vibrator 70 and the rising edge of the vibration waveform W3 detected by the vibration sensor 50b as the vibration transmission time T2. The vibration transmission time T1 is the time required for vibration transmission in the section R1. Moreover, the vibration transmission time T2 is the time required for vibration transmission in the section R2.

[0035] Here, the method of calculating the vibration transmission time is not limited to the method of detecting the rising edge of the waveform. For example, the vibration transmission time can be calculated by the time difference between the peak time points of each waveform. The peak time points can be extracted, for example, by calculating the cross-correlation function between each waveform.

[0036] In step S5, the processor 61 calculates the vibration transmission velocity characteristic using the distance L1 of the section R1, the distance L2 of the section R2, the vibration transmission time T1, and the vibration transmission time T2. The vibration transmission velocity v1 in the section R1 is calculated by v1=L1 / T1, and the vibration transmission velocity v2 in the section R2 is calculated by v2=L2 / T2. The vibration transmission velocity characteristic L(t) is obtained by plotting these relationships, for example, as a graph. FIG. 6 is a diagram showing an example of the vibration transmission velocity characteristic L(t) calculated based on the setting of the vibration transmission path R in FIG. 4. The horizontal axis of the graph in FIG. 6 is the vibration transmission time, and the vertical axis is the distance. The slope of the graph in FIG. 6 is the vibration transmission velocity. The graph in FIG. 6 can be created by plotting points (0,0), (T1,L1), and (T1+T2,L1+L2) on a coordinate plane and connecting these points with a broken line. In reality, the vibration transmission velocity also changes depending on the frequency of the vibration. Therefore, it is desirable to create the graph of FIG. 6 for typical frequencies that are expected to cause abnormal vibrations in the device 1.

[0037] Here, as can be seen from Fig. 6, the vibration transmission velocity may differ for each divided section. This indicates that the vibration transmission velocity differs depending on the part to which the vibration is transmitted. Note that the vibration transmission velocity calculated in the embodiment is the average value of the vibration transmission velocity within the section.

[0038] In step S6, the processor 61 stores the data of the vibration transmission velocity characteristic L(t) obtained in step S5 in the storage 64 as the vibration transmission velocity characteristic data 642. After that, the processor 61 ends the process of FIG.

[0039] As described above, the waveform of the excitation wave used as the output of the vibration exciter 70 when vibrating the vibration transmission path R includes an impact waveform, a sine waveform, a frequency sweep waveform, and a random waveform. There are advantages and disadvantages to using each waveform. The advantages and disadvantages of using each waveform will be described below. 1) The impulse waveform Advantages: It can measure vibration transmission velocity for vibrations of multiple frequencies simultaneously. In addition, since the main cause of failure of industrial equipment is scratches caused by wear on the contact parts of each element of the equipment, inputting a shock waveform is suitable for simulating a malfunctioning equipment. Disadvantages: Since the frequency of the input vibration depends on the rigidity of the vibration position, it is difficult to eliminate noise. 2) Sine waveform Advantages: Signal generation is easy. In addition, since the input signal is a single frequency, it is easy to remove noise by band-pass filtering. Disadvantages: It takes time to measure the vibration transmission velocity for vibrations of multiple frequencies. 3) Frequency sweep waveform Advantages: It is possible to measure vibration transmission velocity for multiple frequencies at once. It is easy to remove noise by band-pass filtering. Disadvantages: Since the frequency of the excitation wave is changed continuously, the rate of change of the frequency must be slowed down in order to achieve high accuracy. In this case, measurement takes time. 4) Random waveform Advantages: It is possible to measure vibration transmission velocity for multiple frequencies at once. Disadvantages: Measurements are performed with a mixture of excitation waves of multiple frequencies, making it difficult to eliminate noise.

[0040] In addition, in the embodiment, a method using a rise time and a method using a cross-correlation function are given as a method for calculating the vibration transmission time. Each of these methods has advantages and disadvantages. The advantages and disadvantages of using each calculation method will be described below. 1) Method using rise time Advantage: Waveform processing is easy. Disadvantages: It is necessary to apply band-pass filtering in advance to remove noise. 2) Method using cross-correlation function Advantages: High accuracy in removing noise. No need to apply bandpass filter processing. Disadvantages: Compared to the method using rise time, waveform processing is more complicated.

[0041] As described above, since there are advantages and disadvantages for each type of excitation wave and each type of calculation method for the vibration transmission time, it is desirable to select an appropriate type of excitation wave and a suitable type of calculation method for the vibration transmission time according to the embodiment. This selection can be made, for example, by an operator.

[0042] Next, the vibration source estimation process will be described. FIG. 7 is a flowchart showing an example of the vibration source estimation process. Prior to the process of FIG. 7, it is assumed that vibration transmission speed characteristic data 642 is stored in, for example, the storage 64 of the control device 60. The process of FIG. 7 is executed when vibration occurs during actual operation of the device 1. For example, it is assumed that point P in FIG. 8 is the vibration source. In this case, the vibration generated at the vibration source P is transmitted through the vibration transmission path R11 and the vibration transmission path R22. The processor 61 obtains the vibration waveform by removing noise in the output signal of the vibration sensor 50a and the output signal of the vibration sensor 50b.

[0043] In step S11, the processor 61 calculates the difference Δt between the vibration transmission time of the vibration transmitted from the vibration source to the vibration sensor 50a and the vibration transmission time of the vibration transmitted from the vibration source to the vibration sensor 50b by comparing the waveforms of the output signals of the vibration sensors 50a and 50b. As a method for calculating the difference in vibration transmission time, for example, a method for detecting the rising edge of the waveform and a method for detecting the peak time difference by a cross-correlation function can be used. For example, the method for detecting the difference Δt in vibration transmission time by the rising edge of the waveform may be the same as the method described with reference to FIG. 5, except that the waveforms to be compared are different.

[0044] In step S12, the processor 61 reads the vibration transmission velocity characteristic data 642 stored in the storage 64, for example.

[0045] In step S13, the processor 61 estimates the position of the vibration source P using the vibration transmission speed characteristic data 642 and the difference Δt in the vibration transmission time. In the embodiment, when vibration occurs in the device 1, it is assumed that any position on the vibration transmission path R is the vibration source. In this case, a time difference Δt may occur between the vibration transmitted from the vibration source to the vibration sensor 50a and the vibration transmitted from the vibration source to the vibration sensor 50b due to the difference in the vibration transmission distance and the difference in the vibration transmission speed for each section of the vibration transmission path R. Here, the entire distance L of the vibration transmission path R, the distance L1 of the section R1, the distance L2 of the section R2, the vibration transmission speed v1 in the section R1, and the vibration transmission speed v2 in the section R2 are known. Therefore, the distance from the vibration sensor 50a to the vibration source P, that is, the distance La of the vibration transmission path R11, can be estimated based on the time difference Δt. Specifically, the processor 61 estimates the distance La according to the relationship of the following (Equation 1).

number

[0046] In step S14, the processor 61 outputs the estimation result. After that, the processor 61 ends the process of Fig. 7. For example, the processor 61 displays a schematic diagram of the device 1 on the display, and further displays the position of the vibration source P on the schematic diagram. The position of the vibration source P is a position at a distance La along the vibration transfer path R from the position of the vibration sensor 50a.

[0047] As described above, in the embodiment, the vibration transmission speed for each section of the vibration transmission path assumed in the equipment is measured in advance, and the position of the vibration source is estimated based on the vibration transmission speed for each section. In the case of equipment having a configuration in which a motor and a gear box are connected via a coupling, which is often commonly used in industrial equipment, the positions of the bearing and the gear are often known in advance. If the positions of the bearing and the gear are known in advance, the vibration transmission path can be specified in advance. On the other hand, if the vibration transmission path has a complex shape, the vibration transmission speed may change depending on the location. In the embodiment, the vibration transmission speed is measured for each section, so that the approximate position of the vibration source can be estimated. This makes it possible to identify the mechanical element causing the abnormal vibration to some extent. In this way, in the embodiment, abnormal vibration in equipment having a complex shape can be measured.

[0048] [Variations] Modifications of the embodiment will be described below. In the above-described embodiment, a method for improving the accuracy of estimating the position of the vibration source includes shortening the distance between the vibrator 70 and the vibration sensors 50a and 50b when measuring the vibration transmission velocity characteristics. For example, at the stage of manufacturing the device 1, the vibration sensor 50a can be incorporated in the support portion of the bearing 22c of the gear box 20. By incorporating the vibration sensor 50a in the support portion of the bearing 22c of the gear box 20, the distance between the vibrator 70 and the vibration sensor 50a can be shortened. Similarly, the vibration sensor 50b can be incorporated in the support portion of the bearing 13b of the motor 10. By incorporating the vibration sensor 50b in the support portion of the bearing 13b of the motor 10, the distance between the vibrator 70 and the vibration sensor 50b can be shortened.

[0049] In addition, in the embodiment, the vibration transmission path R is divided into two sections. Increasing the number of divisions of the sections also shortens the distance of each section, and as a result, the estimation accuracy of the position of the vibration source can be improved. The number of divisions of the sections can be increased, for example, by increasing the number of vibration sensors arranged on the vibration transmission path R or increasing the positions to be vibrated by the vibrator. For example, in FIG. 4, the section can be divided into three by further vibrating the vicinity of the rotation axis of the rotor 11 of the motor 10 by the vibrator 70. Similarly, for example, in FIG. 4, the section can be divided into three by attaching a vibration sensor to the coupling 40.

[0050] FIG. 9 is a diagram showing an example of vibration transmission velocity characteristics L(t) when the number of sections is n (n is an integer of 2 or more). The horizontal axis of the graph in FIG. 9 is vibration transmission time, and the vertical axis is distance. The slope of the graph in FIG. 9 is vibration transmission velocity. The graph in FIG. 9 can be created by plotting points (0,0), (T1,L1), (T1+T2,L1+L2), ..., (T1+T2+...+Tn-1+Tn,L1+L2+...Ln-1+Ln) on a coordinate plane and connecting these points with a broken line. In reality, the vibration transmission velocity also changes depending on the frequency of vibration. Therefore, it is desirable to create the graph in FIG. 9 for representative frequencies assumed to be abnormal vibrations of the equipment 1. In addition, in reality, there are restrictions on the positions at which the vibration sensor and the vibrator can be attached due to the structure of the equipment 1, etc. When measuring the vibration transmission velocity characteristics, the mounting positions of the vibration sensor and the vibrator in the equipment 1 are set according to this restriction, and the measurement is performed.

[0051] 9 is basically the same as when n is 2. Specifically, the processor 61 estimates the distance La according to the relationship in the following (Equation 2).

number

[0052] In the above-described embodiment, an example of estimating a vibration source for an apparatus having a configuration in which a motor and a gearbox are connected via a coupling, which is often commonly used in industrial equipment, is described. In contrast, the embodiment can be applied to various apparatuses having elements that can be vibration sources. However, since the method of the embodiment estimates the position of the vibration source on the vibration transmission path, it is important that the actually assumed vibration source is on a vibration transmission path that is set in advance. Therefore, the method of the embodiment is particularly effective for an apparatus in which the position of the assumed vibration source can be roughly identified.

[0053] In the embodiment, an example in which the vibration transmission velocity characteristic is a graph is described. However, the vibration transmission velocity characteristic does not necessarily have to be a graph. For example, the vibration transmission velocity characteristic may be a table in which the distance, the vibration transmission time, and the vibration transmission velocity are stored in association with each other for each section.

[0054] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0055] 1 Equipment, 10 Motor, 11 Rotor, 12 Stator, 13a, 13b Bearings, 20 Gearbox, 21a, 21b Gears, 22a, 22b, 22c, 22d Bearings, 30 Driven Object, 40 Coupling, 50a, 50b Vibration Sensor, 60 Control Device, 61 Processor, 62 ROM, 63 RAM, 64 Storage, 65 Input Interface, 66 Output Interface, 70 Vibrator, 611 Noise Removal Unit, 612 Characteristics Calculation Unit, 613 Vibration Source Estimation Unit, 614 Vibration Control Unit, 641 Program, 642 Vibration Transmission Velocity Characteristics Data.

Claims

1. a characteristic calculation unit that calculates, when a predetermined position of a vibration transmission path, which starts at a position of a first vibration sensor arranged on an equipment and ends at a position of a second vibration sensor arranged on the equipment, using a vibration exciter, a first vibration transmission velocity based on a first distance along the vibration transmission path from the first vibration sensor to the vibration exciter and a first vibration transmission time until an excitation wave is transmitted from the vibration exciter to the first vibration sensor, and a second vibration transmission velocity based on a second distance along the vibration transmission path from the second vibration sensor to the vibration exciter and a second vibration transmission time until an excitation wave is transmitted from the vibration exciter to the second vibration sensor, as a vibration transmission velocity characteristic of the equipment; a vibration source estimation unit that estimates a position where a vibration has occurred in the device based on a time difference between a vibration transmission time until the vibration is transmitted to the first vibration sensor and a time difference between a vibration transmission time until the vibration is transmitted to the second vibration sensor and the vibration transmission velocity characteristic when a vibration has occurred in the device; An abnormal vibration measuring device for equipment equipped with the above.

2. At least one third vibration sensor is further disposed on the vibration transmission path; the characteristic calculation unit further calculates, as the vibration transmission velocity characteristic, a third vibration transmission velocity based on a third distance along the vibration transmission path from each of the third vibration sensors to a position of the vibration exciter and a third vibration transmission time until an excitation wave is transmitted from the vibration exciter to each of the third vibration sensors; The abnormal vibration measuring device for equipment according to claim 1.

3. The vibrator excites two or more positions on the vibration transmission path, the characteristic calculation unit further calculates, as the vibration transmission velocity characteristic, a fourth vibration transmission velocity based on a fourth distance along the vibration transmission path from the first vibration sensor to a position of each of the oscillators and a fourth vibration transmission time until an excitation wave is transmitted from each of the oscillators to the first vibration sensor, and a fifth vibration transmission velocity based on a fifth distance along the vibration transmission path from the second vibration sensor to a position of each of the oscillators and a fifth vibration transmission time until an excitation wave is transmitted from each of the oscillators to the second vibration sensor. The abnormal vibration measuring device for equipment according to claim 1.

4. 4. The abnormal vibration measuring device for equipment according to claim 1, wherein the excitation wave is any one of an impact waveform, a sine waveform, a frequency sweep waveform, and a random waveform.

5. the characteristic calculation unit calculates the first vibration transmission time by comparing a rise time between the waveform of the excitation wave and a first vibration waveform detected by the first vibration sensor, and calculates the second vibration transmission time by comparing a rise time between the waveform of the excitation wave and a second vibration waveform detected by the second vibration sensor. The abnormal vibration measuring device for equipment according to any one of claims 1 to 4.

6. the characteristic calculation unit calculates the first vibration transmission time by calculating a cross-correlation function between a waveform of the excitation wave and a first vibration waveform detected by the first vibration sensor, and calculates the second vibration transmission time by calculating a cross-correlation function between the waveform of the excitation wave and a second vibration waveform detected by the second vibration sensor; The abnormal vibration measuring device for equipment according to any one of claims 1 to 4.

7. A vibrator vibrates a predetermined position of a vibration transmission path having a starting point at a position of a first vibration sensor arranged on the equipment and an ending point at a position of a second vibration sensor arranged on the equipment; a characteristic calculation unit calculates, as vibration transmission velocity characteristics of the device, a first vibration transmission velocity based on a first distance along the vibration transmission path from the first vibration sensor to a position of the oscillator and a first vibration transmission time until an excitation wave is transmitted from the oscillator to the first vibration sensor, and a second vibration transmission velocity based on a second distance along the vibration transmission path from the second vibration sensor to the position of the oscillator and a second vibration transmission time until an excitation wave is transmitted from the oscillator to the second vibration sensor; a vibration source estimation unit estimating a position where a vibration has occurred in the device based on a time difference between vibration transmission times until the vibration is transmitted to the first vibration sensor and the second vibration sensor, and the vibration transmission velocity characteristic, when a vibration has occurred in the device; A method for measuring abnormal vibration in equipment having the above.

8. vibrating a predetermined position of a vibration transmission path having a start point at a position of a first vibration sensor arranged on the equipment and an end point at a position of a second vibration sensor arranged on the equipment, by a vibrator; calculating, as vibration transmission velocity characteristics of the device, a first vibration transmission velocity based on a first distance along the vibration transmission path from the first vibration sensor to a position of the oscillator and a first vibration transmission time until an excitation wave is transmitted from the oscillator to the first vibration sensor, and a second vibration transmission velocity based on a second distance along the vibration transmission path from the second vibration sensor to a position of the oscillator and a second vibration transmission time until an excitation wave is transmitted from the oscillator to the second vibration sensor; When vibration occurs in the device, estimating a position where vibration has occurred in the device based on a time difference between vibration transmission times until the vibration is transmitted to the first vibration sensor and the second vibration sensor, and the vibration transmission velocity characteristic; A program for measuring abnormal vibrations in equipment, which is executed on a computer.

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