Vibration characteristic estimation device, rotation balance adjustment device, vibration characteristic estimation method, and rotation balance adjustment method

Abstract

A vibration characteristic estimation device (10) comprises: an acquisition unit that acquires data on the vibration vector of a system (1) having a rotating shaft (2) and a bearing (3), and data on the rotation speed of the rotating shaft (2); an optimization calculation unit (12) that determines, on the assumption that an open-loop transfer function of the system (1) including the equivalent mass of the rotating shaft (2) as a variable is expressed using the equivalent mass and the vibration vector, an evaluation function that represents the absolute value of the difference between a gain slope of the open-loop transfer function at a first rotation speed and a gain slope of the open-loop transfer function at a second rotation speed, and calculates an optimum equivalent mass, which is the equivalent mass that results in the minimum value for the evaluation function, the first rotation speed and the second rotation speed being two rotation speeds at which the rate of increase in the vibration vector is positive; and an estimation unit (14) that estimates a critical speed of the rotating shaft (2) on the basis of the open-loop transfer function determined on the basis of the optimum equivalent mass and a detected vibration vector.

Description

[Technical Field]

[0001] The present disclosure relates to a vibration characteristic estimation device, a rotational balance adjustment device, a vibration characteristic estimation method, and a rotational balance adjustment method that estimate vibration characteristics of a system having a rotating shaft. [Background technology]

[0002] In rotating machinery, excitation forces with rotational frequency components are generated due to unbalance in the rotating body. Unbalance occurs when the centroid on the center line of the rotating shaft is offset from the center of gravity of the rotating body. Vibrations caused by excitation forces increase sharply, especially when the rotation speed matches the natural frequency of the rotating shaft. The rotation speed that matches the natural frequency is called the critical speed. If the rotation speed of a rotating machine is increased to a critical speed without measures being taken to prevent vibration, problems such as damage to the rotating machine may occur. Therefore, conventionally, field balancing has been used to correct the unbalance of the rotating body, thereby reducing vibration.

[0003] Patent Document 1 discloses a method for correcting unbalance using field balancing, in which a stationary rotating body is excited to detect vibrations, and a transfer function is obtained in which the excitation force is input and the vibration generated in the rotating body is the response, thereby measuring the natural frequency of the rotating shaft. Furthermore, the method described in Patent Document 1 obtains the vibration response of the rotating body when it is rotated, and then divides the vibration response by the transfer function to determine the amount of unbalance at a critical speed and the phase indicating the unbalance position. According to the method described in Patent Document 1, the unbalance of the rotating body is corrected by placing a correction weight with a weight corresponding to the determined amount of unbalance in a position symmetrical to the determined unbalance position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-194653 Summary of the Invention [Problem to be solved by the invention]

[0005] In the method described in Patent Document 1, the natural frequency is measured based on the transfer function when the rotating body is stationary. With the method described in Patent Document 1, changes in bearing characteristics due to changes in rotational speed are not reflected in the transfer function, making it difficult to accurately estimate the critical speed. In this case, due to the difficulty in accurately estimating the critical speed, the balancing process must be repeated. Thus, the conventional technology described in Patent Document 1 has the problem of making it difficult to accurately estimate the critical speed of a rotating shaft.

[0006] The present disclosure has been made in view of the above, and has an object to provide a vibration characteristics estimation device that can accurately estimate the critical speed of a rotating shaft. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the object, a vibration characteristics estimation device according to the present disclosure includes an acquisition unit that acquires operating data including data on a vibration vector of a system that includes a rotating shaft and a bearing that rotatably supports the rotating shaft and that is detected when the rotating shaft is rotated, and data on the rotational speed of the rotating shaft when the vibration vector is detected. The vibration characteristics estimation device according to the present disclosure includes an optimization calculation unit that expresses an open-loop transfer function of the system in terms of the equivalent mass and the vibration vector, using the equivalent mass of the rotating shaft as a variable, and calculates an optimal equivalent mass, which is the equivalent mass that minimizes the evaluation function, for a first rotational speed and a second rotational speed that are two rotational speeds at which the rate of rise of the vibration vector is positive. The vibration characteristics estimation device according to the present disclosure also includes an estimation unit that estimates a critical speed of the rotating shaft based on the open-loop transfer function determined based on the optimal equivalent mass and the detected vibration vector. [Effects of the Invention]

[0008] The vibration characteristics estimation device according to the present disclosure has the effect of being able to accurately estimate the critical speed of a rotating shaft. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a vibration characteristics estimation device according to a first embodiment. [Figure 2] 1 is a flowchart showing a processing procedure performed by a vibration characteristics estimation device according to a first embodiment; [Figure 3] FIG. 1 is a diagram showing an example of a vibration model of a system whose vibration characteristics are estimated by a vibration characteristics estimation device according to a first embodiment; [Figure 4] 1 is a block diagram showing a closed-loop transfer function of a system according to a first embodiment. [Figure 5] A modified version of the block diagram shown in Figure 4 [Figure 6] FIG. 10 is a diagram showing an example of the relationship between the gain of the closed-loop transfer function of the system and the rotation speed according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing an example of the relationship between the gain of the open-loop transfer function of the system and the rotation speed according to the first embodiment. [Figure 8] FIG. 10 is a diagram for explaining a change in the gain of the open-loop transfer function when the equivalent mass is changed in the system of the first embodiment. [Figure 9] FIG. 1 is a diagram showing an example of a response surface of an evaluation function used to search for an optimal equivalent mass in the first embodiment. [Figure 10] A diagram showing the graph shown in FIG. 8 and the rotation speed. [Figure 11] FIG. 10 is a diagram for explaining the gain of unbalance vibration obtained from operation data in the first embodiment. [Figure 12] FIG. 1 is a diagram for explaining the gain of unbalance vibration in a measurement band and an unmeasured band according to the first embodiment; [Figure 13] FIG. 1 is a diagram for explaining an open-loop transfer function determined from operational data in a measurement band in the first embodiment. [Figure 14]FIG. 1 is a diagram for explaining extrapolation of an open-loop transfer function of an unmeasured band in the vibration characteristics estimation device according to the first embodiment. [Figure 15] FIG. 10 is a diagram showing a configuration example of a rotation balance adjustment device according to a second embodiment; [Figure 16] 10 is a flowchart showing a processing procedure performed by the rotational balance adjustment device according to the second embodiment. [Figure 17] FIG. 10 is a diagram for explaining correction of imbalance by attaching a correction weight according to the calculation result of the rotational balance adjustment device according to the second embodiment. [Figure 18] FIG. 10 is a diagram showing a configuration example of a rotation balance adjustment device according to a third embodiment. [Figure 19] 10 is a flowchart showing a processing procedure performed by the rotational balance adjustment device according to the third embodiment. [Figure 20] FIG. 10 is a diagram for explaining correction of imbalance by attaching a correction weight according to the calculation result of the rotational balance adjustment device according to the third embodiment. [Figure 21] FIG. 1 is a diagram showing a configuration example of a control circuit according to first to third embodiments; [Figure 22] FIG. 1 is a diagram showing an example of the configuration of a dedicated hardware circuit according to first to third embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0010] A vibration characteristic estimation device, a rotation balance adjustment device, a vibration characteristic estimation method, and a rotation balance adjustment method according to embodiments will be described in detail below with reference to the accompanying drawings.

[0011] Embodiment 1 FIG. 1 is a diagram illustrating an example of the configuration of a vibration characteristics estimation device 10 according to a first embodiment. The vibration characteristics estimation device 10 is a device that performs calculations to estimate vibration characteristics. FIG. 1 illustrates the vibration characteristics estimation device 10 and a system 1, which is the target of vibration characteristics estimation by the vibration characteristics estimation device 10. The system 1 has a rotating shaft 2 and two bearings 3 that rotatably support the rotating shaft 2. A vibration sensor 4 and a rotation sensor 5 are attached to the system 1. The vibration sensor 4 detects a vibration vector of the system 1 and outputs a vibration vector signal indicating the detection result of the vibration vector. The rotation sensor 5 detects the rotation speed of the rotating shaft 2 and outputs a rotation speed signal indicating the detection result of the rotation speed. The vibration vector signal and the rotation speed signal are input to the vibration characteristics estimation device 10.

[0012] 1 schematically shows a rotating shaft 2 and a bearing 3 that constitute a system 1, and a vibration sensor 4 and a rotation sensor 5 that are attached to the system 1. Note that each of the vibration sensor 4 and the rotation sensor 5 described here is a device external to the vibration characteristics estimation device 10. At least one of the vibration sensor 4 and the rotation sensor 5 may be a device included in the vibration characteristics estimation device 10.

[0013] The vibration characteristic estimation device 10 includes a signal collection unit 11 that collects vibration vector signals and rotational speed signals, an optimization calculation unit 12 that executes optimization calculation processing, an open-loop transfer function calculation unit 13 that calculates an open-loop transfer function, and an estimation unit 14 that estimates the critical speed of the rotating shaft 2.

[0014] The signal collecting unit 11 functions as an acquiring unit that acquires operating data of the system 1. The operating data includes data on vibration vectors of the system 1 detected when the rotating shaft 2 in the system 1 is rotated, and data on the rotation speed of the rotating shaft 2 when the vibration vector is detected. The signal collecting unit 11 acquires the operating data by collecting vibration vector signals and rotation speed signals. The signal collecting unit 11 stores the acquired operating data. The signal collecting unit 11 outputs the acquired operating data to the optimization calculation unit 12.

[0015] The optimization calculation unit 12 expresses the open-loop transfer function of the system 1 as an equivalent mass and a vibration vector, using the equivalent mass of the rotating shaft 2 as a variable, and calculates an evaluation function that represents the absolute value of the difference between the gain gradient of the open-loop transfer function at a first rotational speed and the gain gradient of the open-loop transfer function at a second rotational speed, for two rotational speeds, a first rotational speed and a second rotational speed, at which the rate of rise of the vibration vector is positive.The optimization calculation unit 12 also calculates an optimal equivalent mass, which is the equivalent mass when the calculated evaluation function is minimum.The optimization calculation unit 12 outputs the calculation result of the optimal equivalent mass to the open-loop transfer function calculation unit 13.

[0016] In the first embodiment, the equivalent mass is a variable corresponding to the mass of the rotating shaft 2. The evaluation function uses the equivalent mass as a variable and expresses the absolute value of the difference between the gain gradient of the open-loop transfer function at the first rotational speed and the gain gradient of the open-loop transfer function at the second rotational speed, using the vibration vector detected when the rotational speed is the first rotational speed and the vibration vector and equivalent mass detected when the rotational speed is the second rotational speed. The second rotational speed is a rotational speed higher than the first rotational speed. Furthermore, each of the first rotational speed and the second rotational speed is a rotational speed lower than the critical speed of the rotating shaft 2.

[0017] The rate of increase of the vibration vector at the first rotation speed and the rate of increase of the vibration vector at the second rotation speed are equal to or less than a preset value. Here, the rate of increase of the vibration vector refers to the rate of increase of the magnitude of the vibration vector. In the following description, the gain of the vibration vector refers to the magnitude of the vibration vector. The gain of the vibration vector is the absolute value of a complex number representing the vibration vector, expressed in decibels. The rate of increase of the vibration vector represents the degree of increase in gain as the rotation speed increases. When the rotation speed approaches a critical speed, the gain increases rapidly.

[0018] For each of the first and second rotation speeds, a rotation speed is set such that the rate of increase of the vibration vector from before the increase of the vibration vector is 1.5 times or less. That is, the rate of increase of the vibration vector at each of the first and second rotation speeds is a preset value of 1.5 or less. Here, "before increase" refers to one step before the first rotation speed and the second rotation speed. Here, "step" refers to a step in which the rotation speed is increased. For example, assuming that the rotation speed is increased in 1 Hz increments, the time before the first rotation speed is reached and the rotation speed is 1 Hz lower than the first rotation speed is the time before the increase of the first rotation speed. Similarly, the time before the second rotation speed is reached and the rotation speed is 1 Hz lower than the second rotation speed is the time before the increase of the second rotation speed. For example, if the second rotation speed is 65 Hz, the ratio of the magnitude of the vibration vector one step before when the rotation speed is 64 Hz to the magnitude of the vibration vector when the rotation speed is 65 Hz is the rate of increase for the second rotation speed. In order to improve the accuracy of estimating the critical speed, the rate of increase of the vibration vector may be set to 1.3 or less. In order to further improve the accuracy of estimating the critical speed, the rate of increase of the vibration vector may be set to 1.1 or less. In other words, the preset value is not limited to 1.5, and may be a value such as 1.3 or 1.1.

[0019] The calculation result of the optimal equivalent mass is input to the open-loop transfer function calculation unit 13. The operating data stored in the signal collection unit 11 is input to the open-loop transfer function calculation unit 13 via the optimization calculation unit 12. The open-loop transfer function calculation unit 13 determines an open-loop transfer function based on the optimal equivalent mass and the operating data. The open-loop transfer function calculation unit 13 outputs the determined open-loop transfer function to the estimation unit 14.

[0020] The estimation unit 14 estimates the critical rotation speed and vibration characteristics of the system 1 based on the open-loop transfer function. The estimation unit 14 estimates the critical speed and vibration characteristics of the system 1 by extrapolating the open-loop transfer function of a rotation speed higher than the rotation speed indicated by the rotation speed signal stored in the signal collection unit 11.

[0021] Next, a description will be given of the processing performed by the vibration characteristics estimation device 10. Fig. 2 is a flowchart showing the procedure of the processing performed by the vibration characteristics estimation device 10 according to the first embodiment.

[0022] In step S1, the signal collector 11 acquires operating data including data on vibration vectors detected when the rotating shaft 2 is rotated and data on the rotation speed of the rotating shaft 2 when the vibration vectors are detected. The signal collector 11 collects vibration vector signals and rotation speed signals when the rotating shaft 2 is rotating at a first rotation speed, and vibration vector signals and rotation speed signals when the rotating shaft 2 is rotating at a second rotation speed. In this way, the signal collector 11 acquires operating data when the rotating shaft 2 is rotating at the first rotation speed and operating data when the rotating shaft 2 is rotating at the second rotation speed.

[0023] In step S2, the optimization calculation unit 12 calculates an evaluation function that represents the absolute value of the difference in gain gradient of the open-loop transfer function between the first rotational speed and the second rotational speed, and searches for an optimal equivalent mass that is the equivalent mass when the evaluation function is minimized, based on the evaluation function. The open-loop transfer function of the system 1 is expressed by the equivalent mass and the vibration vector, with the equivalent mass of the rotating shaft 2 as a variable. The optimization calculation unit 12 outputs information about the optimal equivalent mass calculated by the search to the open-loop transfer function calculation unit 13.

[0024] In step S3, the open-loop transfer function calculation unit 13 calculates an open-loop transfer function based on the optimal equivalent mass and the vibration vector and rotational speed indicated in the operating data. The open-loop transfer function calculation unit 13 outputs the open-loop transfer function to the estimation unit 14. In step S4, the estimation unit 14 estimates the critical speed of the rotating shaft 2 based on the open-loop transfer function. With this, the vibration characteristic estimation device 10 ends the processing according to the procedure shown in FIG. 2.

[0025] Next, a description will be given of an algorithm for searching for the optimum equivalent mass using an evaluation function by the vibration characteristic estimation device 10. Here, the explanation will be given by replacing the system 1 with a vibration model of a one-degree-of-freedom system.

[0026] First, we will explain the closed-loop transfer function and open-loop transfer function of system 1. Fig. 3 is a diagram showing an example of a vibration model of system 1 whose vibration characteristics are estimated by vibration characteristics estimation device 10 according to the first embodiment. In the vibration model shown in Fig. 3, m represents the mass of rotating shaft 2, which is a rotating body, k represents stiffness that encompasses the stiffness of rotating shaft 2 and the stiffness of bearing 3, c represents damping that encompasses the damping of rotating shaft 2 and the damping of bearing 3, and z represents the displacement of rotating shaft 2 due to vibration.

[0027] When the rotation speed is Ω at unbalance U, the unbalance force acts as an exciting force and is applied to the vibration model. This relationship can be expressed as the equation of motion for vibration due to unbalance, as shown in the following equation (1).

[0028]

number

[0029] The input-output relationship of equation (1), i.e., the closed-loop transfer function, G c (s) is expressed by the following equation (2).

[0030]

number

[0031] FIG. 4 is a block diagram showing a closed-loop transfer function of the system 1 in the first embodiment. FIG. 5 is a diagram showing a modified version of the block diagram shown in FIG. 4. The block diagram shown in FIG. 5 shows the block of the closed-loop transfer function shown in FIG. 4 as a controller G r Blocks and control object G p The "-" in Figure 5 indicates that it acts as a feedback. r The block combines stiffness k and damping c. Stiffness k and damping c are parameters that control the vibration characteristics of the vibration model. Control object G p The block is the control object G p The controller G is a block containing a mass m. r Control target G p The open-loop transfer function of the vibration model is expressed by multiplying o (s) is expressed by the following equation (3).

[0032]

number

[0033] Here, we are dealing with the response to vibration due to imbalance, so the excitation frequency is Ω, which is the rotational speed. By substituting s = jΩ into equation (2), we obtain the following equation (4). By substituting s = jΩ into equation (3), we obtain the following equation (5).

[0034]

number

[0035]

number

[0036] FIG. 6 is a diagram illustrating an example of the relationship between the gain of the closed-loop transfer function of the system 1 according to the first embodiment and the rotation speed. FIG. 7 is a diagram illustrating an example of the relationship between the gain of the open-loop transfer function of the system 1 according to the first embodiment and the rotation speed. FIG. 6 shows a graph illustrating the relationship between the gain of the closed-loop transfer function shown in Equation (4) and the rotation speed. FIG. 7 shows a graph illustrating the relationship between the gain of the open-loop transfer function shown in Equation (5) and the rotation speed. In the relationships shown in FIGS. 6 and 7, m=k=1, c=0.02, and U=2. The vertical axis in FIG. 6 and the vertical axis in FIG. 7 both represent values ​​converted to decibel values. The horizontal axis in FIG. 6 and the horizontal axis in FIG. 7 are both logarithmic scales. That is, the graphs shown in FIGS. 6 and 7 are both double logarithmic graphs.

[0037] In the graph shown in Fig. 6, the critical speed is the rotation speed when the gain of the closed loop transfer function is at its peak. In the graph shown in Fig. 7, the critical speed is the rotation speed when the gain of the open loop transfer function is 0 dB. From the graphs shown in Fig. 6 and Fig. 7, it can be seen that the critical speed is 1 rad / sec.

[0038] Next, we will explain how to obtain the open-loop transfer function shown in equation (5) from the motion data when vibration occurs due to unbalance of the rotating shaft 2. In the following explanation, unbalance vibration refers to vibration due to unbalance of the rotating shaft 2. Here, the operating data indicates unbalance vibration in the vibration model shown in Figure 3.

[0039] The right side of equation (1) represents the unbalanced force, which is an external force when the rotation speed is Ω at unbalance U. When such an unbalanced force is input to the block shown in Figure 4, the response z is expressed by the following equation (6).

[0040]

number

[0041] A shown in equation (6) is the vibration vector of z, which is the unbalance response. The vibration vector A is expressed by the following equation (7). The vibration vector A is expressed by multiplying the closed-loop transfer function shown in equation (4) by the unbalance force.

[0042]

number

[0043] Let A, the vibration vector, be the unbalanced vibration. G, the unbalanced vibration u is expressed by the following equation (8).

[0044]

number

[0045] Here, the unbalance vibration G for the unbalance U installed during the balancing work u When using this as operating data, unbalance U and unbalance vibration G u and the rotation speed Ω are known. Therefore, take the reciprocal of both sides of equation (8) and add UΩ to each reciprocal of both sides. 2 By multiplying this, the following equation (9) is obtained.

[0046]

number

[0047] Expected equivalent mass m eq Using m on both sides of equation (9) eq Ω 2 By adding r * is obtained.

[0048]

number

[0049] Both sides of equation (10) are -m eq Ω 2 By dividing by , the open loop transfer function G is obtained as shown in the following equation (11). o * Equation (11) is equivalent to equation (5). Therefore, it can be said that the open-loop transfer function can be obtained by using the operating data and the equivalent mass. The open-loop transfer function is obtained by using the equivalent mass m eq By using this, the variable includes the imbalance U.

[0050]

number

[0051] Here, we will explain how the gain of the open-loop transfer function changes when the equivalent mass is changed for unbalanced vibration under the conditions in Figures 6 and 7. Figure 8 is a diagram for explaining how the gain of the open-loop transfer function changes when the equivalent mass is changed in system 1 of embodiment 1. The five graphs shown in Figure 8 are obtained by changing the equivalent mass m in increments of 0.5 from 1 to 3 in equation (11). eq This shows the gain of the open-loop transfer function when is changed. One of the five graphs shown in Fig. 8 matches the graph shown in Fig. 7. From the above, by searching for an appropriate equivalent mass, it is possible to calculate an open-loop transfer function equivalent to equation (5) from the unbalance vibration and equivalent mass.

[0052] Next, we will explain the algorithm for searching for an optimized equivalent mass, which is an open-loop transfer function equivalent to equation (5). When the equivalent mass is changed as shown in Figure 8, each graph intersects at 0 dB when the rotation speed is at a critical speed. Of the five graphs shown in Figure 8, one that matches the graph shown in Figure 7 is represented by a straight line, and the other four are represented by curves. In other words, the log-log graph of the gain of the open-loop transfer function shown in equation (5) is a straight line. Therefore, in order to search for the optimal equivalent mass, the evaluation function shown in the following equation (12) is set: Ω l is the first rotation speed, Ωu is the second rotation speed.

[0053]

number

[0054] Here, it is assumed that the following equation (13) holds. Re in equation (13) is a symbol representing the real part of a complex number. Note that g in equation (12) o,l * is the rotation speed Ω l g when o * g shown in equation (12) o,u * is the rotation speed Ω u g when o * Let's say. * " is the open-loop transfer function G shown in equation (11) o * This indicates that the parameter is related to

[0055]

number

[0056] Open-loop transfer function G O * In the evaluation function shown in equation (12), the equivalent mass and the rotation speed are variables. l and Omega u Therefore, of the equivalent mass and the rotation speed, only the equivalent mass is a variable. The evaluation function shown in equation (12) is l The gain gradient of the absolute value of the real part of the open loop transfer function and Ω when the horizontal axis is logarithmic u It represents the absolute value of the difference between the absolute value of the real part of the open-loop transfer function and the gain gradient. When the equivalent mass is the optimal equivalent mass, Ω l The gain gradient of the absolute value of the real part of the open-loop transfer function in u Since the gain gradients of the absolute values ​​of the real parts of the open loop transfer functions in are equal to each other, the evaluation function takes the minimum value.

[0057] 9 is a diagram showing an example of a response surface of an evaluation function used to search for an optimal equivalent mass in embodiment 1. FIG. l ,Ω u ,Ω c Ω c is the critical speed. In this example, Ω l is Ω c The rotation speed is 20% of Ω. u is Ω c The rotation speed shall be equivalent to 80% of the

[0058] As shown in Fig. 9, the evaluation function takes the minimum value when the equivalent mass is 2. That is, in the example shown in Fig. 9, the optimum equivalent mass is 2. Of the five graphs shown in Fig. 8, one graph consisting of only straight lines represents the gain of the open-loop transfer function when the equivalent mass is 2.

[0059] As described above, the vibration characteristic estimation device 10 can calculate an open-loop transfer function equivalent to equation (5) based on the operating data and the equivalent mass calculated by the optimization calculation by searching for the optimal equivalent mass that minimizes the evaluation function shown in equation (12).

[0060] Next, a method for estimating a critical speed using operation data up to just before the critical speed will be described. Fig. 11 is a diagram for explaining the gain of unbalance vibration determined from operation data in the first embodiment. Fig. 11 shows an example of the relationship between the rotation speed and the gain of unbalance vibration determined from operation data up to a rotation speed equivalent to 80% of the critical speed, i.e., a second rotation speed. From the relationship shown in Fig. 11, it is unclear how much the gain of unbalance vibration will increase when the rotation speed is higher than the second rotation speed, making it difficult to estimate the critical speed.

[0061] 12 is a diagram for explaining the gain of unbalance vibration in the measurement band and the unmeasurement band according to the first embodiment.u The following rotation speed section shows the relationship between the gain of unbalance vibration and rotation speed in the measurement band where the motion data was measured, and is the same as the graph shown in Figure 11. Ω u The range of rotation speeds higher than Ω is an unmeasured range where no operational data has been measured. u The portion of the rotation speed higher than represents the relationship between the gain of unbalance vibration and the rotation speed in the unmeasured band.

[0062] Fig. 13 is a diagram for explaining the open loop transfer function determined from the operating data in the measurement band in the first embodiment. Fig. 13 shows a graph showing the relationship between the open loop transfer function in the measurement band and the rotation speed. Ω u The open-loop transfer function in the measurement band is determined by substituting the operating data at the following rotational speeds into equations (12) and (13) to search for the optimum equivalent mass.

[0063] Next, the slope of the determined open-loop transfer function and the intercept of the determined open-loop transfer function are derived from a linear function relation, and the rotation speed is given as a dependent variable, thereby extrapolating the open-loop transfer function of the unmeasured band.

[0064] FIG. 14 is a diagram for explaining the extrapolation of the open-loop transfer function of the unmeasured band in the vibration characteristics estimation device 10 according to the first embodiment. FIG. 14 shows a graph representing the relationship between the rotation speed and the open-loop transfer function, which is a combination of the open-loop transfer function shown in FIG. 13 and the extrapolated open-loop transfer function. The graph shown in FIG. 14 coincides with the graph shown in FIG. 7. In this way, the vibration characteristics estimation device 10 can determine the critical speed by searching for the rotation speed at which the graph showing the gain of the extrapolated open-loop transfer function intersects with the line indicating 0 dB.

[0065] According to the first embodiment, the vibration characteristics estimation device 10 calculates an evaluation function that represents the absolute value of the difference between the gain gradient of the open-loop transfer function at a first rotational speed and the gain gradient of the open-loop transfer function at a second rotational speed, and calculates the optimal equivalent mass based on the evaluation function. The vibration characteristics estimation device 10 estimates the critical speed of the rotating shaft 2 based on the open-loop transfer function determined based on the optimal equivalent mass and the detected vibration vector. The vibration characteristics estimation device 10 estimates the critical speed based on operating data that takes into account the characteristics of the bearings 3 in the system 1, thereby enabling accurate estimation of the critical speed. The vibration characteristics estimation device 10 does not need to store the vibration characteristics of systems other than the system 1 or the vibration characteristics at rest, and can estimate the critical speed based on the operating data of the system 1, whose vibration characteristics are to be estimated. Because the vibration characteristics estimation device 10 estimates the critical speed by extrapolating the open-loop transfer function, there is no need to actually increase the rotational speed to the critical speed, and the critical speed can be determined while preventing malfunctions such as damage to the system 1. As a result, the vibration characteristic estimation device 10 has the effect of being able to accurately estimate the critical speed of the rotating shaft 2.

[0066] Embodiment 2 FIG. 15 is a diagram showing an example of the configuration of a rotational balance adjustment device 20 according to the second embodiment. The rotational balance adjustment device 20 is a device that performs calculations to correct imbalance in a rotating body. The rotational balance adjustment device 20 has a configuration similar to that of the vibration characteristics estimation device 10 according to the first embodiment. FIG. 15 shows the rotational balance adjustment device 20 and a system 1 whose imbalance is to be corrected. In the second embodiment, the same components as those in the first embodiment above are assigned the same reference numerals, and the following mainly describes the configuration that differs from the first embodiment.

[0067] A vibration vector signal indicating the detection result by the vibration sensor 4 and a rotation speed signal indicating the detection result by the rotation sensor 5 are input to the rotation balance adjustment device 20. Note that the vibration sensor 4 and the rotation sensor 5 described here are each devices external to the rotation balance adjustment device 20. At least one of the vibration sensor 4 and the rotation sensor 5 may be a device included in the rotation balance adjustment device 20.

[0068] The rotational balance adjustment device 20 includes a signal collection unit 11, an optimization calculation unit 12, an open-loop transfer function calculation unit 13, and an estimation unit 14, which are configured similarly to the vibration characteristic estimation device 10 shown in FIG. 1. The rotational balance adjustment device 20 also includes a balance calculation unit 21 that calculates the weight and attachment position of a correction weight. The correction weight is a weight used to correct imbalance of a rotating body. In the second embodiment, the correction weight is attached to the rotating shaft 2, which is a rotating body included in the system 1. The balance calculation unit 21 determines the weight of the correction weight and the attachment position of the correction weight on the rotating shaft 2 by calculation that incorporates the estimated critical speed.

[0069] Next, a description will be given of the processing performed by the rotational balance adjustment device 20. Fig. 16 is a flowchart showing the procedure of the processing performed by the rotational balance adjustment device 20 according to the second embodiment.

[0070] In step S11, the signal collector 11 acquires first operating data indicating the vibration vector and rotation speed detected when the rotating shaft 2 is rotated without a test weight attached. The signal collector 11 collects a vibration vector signal and a rotation speed signal when the rotating shaft 2 without a test weight attached is rotating at a first rotation speed, and a vibration vector signal and a rotation speed signal when the rotating shaft 2 without a correction weight attached is rotating at a second rotation speed. In this way, the signal collector 11 acquires first operating data when the rotating shaft 2 is rotating at the first rotation speed and first operating data when the rotating shaft 2 is rotating at the second rotation speed.

[0071] In step S12, the rotational balance adjustment device 20 estimates a critical speed by processing the first operating data acquired in step S11, and determines a first vibration vector corresponding to the estimated critical speed. The optimization calculation unit 12 searches for an optimal equivalent mass based on the first operating data by processing similar to step S2 shown in FIG. 2. The open-loop transfer function calculation unit 13 calculates an open-loop transfer function by processing similar to step S3 shown in FIG. 2. The estimation unit 14 estimates the critical speed of the rotating shaft 2 by processing similar to step S4 shown in FIG. 2. Furthermore, the estimation unit 14 determines a first vibration vector, which is a vibration vector corresponding to the estimated critical speed. The estimation unit 14 outputs information about the first vibration vector to the balance calculation unit 21.

[0072] In step S13, the signal collector 11 acquires second operating data indicating the vibration vector and rotation speed detected when the rotating shaft 2 to which the test weight is attached is rotated. A test weight of an arbitrary weight is attached at an arbitrary position on the rotating shaft 2. The signal collector 11 collects a vibration vector signal and a rotation speed signal when the rotating shaft 2 to which the test weight is attached rotates at a first rotation speed, and a vibration vector signal and a rotation speed signal when the rotating shaft 2 to which the test weight is attached rotates at a second rotation speed. In this way, the signal collector 11 acquires second operating data when the rotating shaft 2 rotates at the first rotation speed and second operating data when the rotating shaft 2 rotates at the second rotation speed.

[0073] In step S14, the rotational balance adjustment device 20 estimates a critical speed by processing the second operating data acquired in step S13, and determines a second vibration vector corresponding to the estimated critical speed. The optimization calculation unit 12 searches for an optimal equivalent mass based on the second operating data by processing similar to step S2 shown in FIG. 2. The open-loop transfer function calculation unit 13 calculates an open-loop transfer function by processing similar to step S3 shown in FIG. 2. The estimation unit 14 estimates the critical speed of the rotating shaft 2 by processing similar to step S4 shown in FIG. 2. Furthermore, the estimation unit 14 determines a second vibration vector, which is a vibration vector corresponding to the estimated critical speed. The estimation unit 14 outputs information about the second vibration vector to the balance calculation unit 21.

[0074] In step S15, the balance calculation unit 21 determines the weight of the correcting weight and the installation position of the correcting weight based on the ratio between the first vibration vector and the effect vector represented by the difference between the second vibration vector and the first vibration vector, and the angle between the first vibration vector and the effect vector.The balance calculation unit 21 determines the weight of the correcting weight based on the ratio between the first vibration vector and the effect vector represented by the difference between the second vibration vector and the first vibration vector.The balance calculation unit 21 determines the installation position of the correcting weight based on the angle between the first vibration vector and the effect vector represented by the difference between the second vibration vector and the first vibration vector.With the above, the rotational balance adjustment device 20 ends the processing according to the procedure shown in FIG.

[0075] Next, we will explain how to correct imbalance by attaching a correction weight based on the calculation results of the rotational balance adjustment device 20. Fig. 17 is a diagram for explaining how to correct imbalance by attaching a correction weight in accordance with the calculation results of the rotational balance adjustment device 20 according to the second embodiment. Fig. 17 shows a Nyquist diagram that represents the locus of the tip of the vibration vector when the rotation speed of the rotating shaft 2 is changed. Here, we will explain how to correct imbalance in the second embodiment by comparing it with conventional field balancing.

[0076] In Figure 17, point O, which is the origin, represents a state where the rotational speed is 0, i.e., a stopped state. Points A and B each represent the tip of the vibration vector when the rotating shaft 2 is rotated at a rotational speed lower than the critical speed. Point A' represents the tip of the vibration vector when the rotating shaft 2 without a test weight attached is rotated at the critical speed. Point B' represents the tip of the vibration vector when the rotating shaft 2 with a test weight attached is rotated at the critical speed. The "'" next to points A' and B' indicates that the points correspond to the critical speed.

[0077] In conventional field balancing, first, without attaching a test weight to the rotating shaft 2, the rotation speed is increased from point O to point A, and the vibration vector OA is measured. Next, with a test weight attached to the rotating shaft 2, the rotation speed is increased from point O to point B, and the vibration vector OB is measured.

[0078] In the example shown in Figure 17, it can be said that the attachment of the test weight caused the tip of the vibration vector to change from point A to point B. The arrow between points A and B in Figure 17 shows how the tip of the vibration vector changes from point A to point B, and represents the effect vector AB. By appropriately adjusting the weight of the correction weight and the attachment position of the correction weight, it is possible to move the tip of the vibration vector closer to point O from point A. In other words, by appropriately adjusting the weight of the correction weight and the attachment position of the correction weight, it is possible to reduce unbalance vibration.

[0079] In the example shown in Figure 17, unbalance vibration can be reduced by making the weight of the correction weight |OA| / |AB| times the weight of the test weight and by shifting the installation position of the correction weight by ∠BAO from the installation position of the test weight. However, with conventional field balancing, it is difficult to reduce unbalance vibration by performing the above operation just once, and it is necessary to repeat the above operation while increasing the rotational speed to a speed close to the critical speed.

[0080] The rotational balance adjustment device 20 according to the second embodiment estimates the critical speed using a configuration similar to that of the vibration characteristic estimation device 10 according to the first embodiment, and can predict a vibration vector OA′ having its tip at point A′ and a vibration vector OB′ having its tip at point B′. In the second embodiment, the vibration vector OA′ is a first vibration vector. The vibration vector OB′ is a second vibration vector. Note that the solid line between points O and A in FIG. 17 represents a trajectory obtained by measurement when no test weight is attached. The dashed line between points A and A′ in FIG. 17 represents a trajectory predicted by estimating the critical speed when no test weight is attached. The solid line between points O and B in FIG. 17 represents a trajectory obtained by measurement when a test weight is attached. The dashed line between points B and B′ in FIG. 17 represents a trajectory predicted by estimating the critical speed when a test weight is attached. The arrow between points A' and B' in FIG. 17 shows how the tip of the vibration vector changes from point A' to point B' when the test weight is attached, and represents the effect vector A'B'.

[0081] The balance calculation unit 21 obtains the weight of the correction weight by multiplying the weight of the trial weight by |OA'| / |A'B'|. The balance calculation unit 21 determines the attachment position of the correction weight to be a position that is shifted by ∠B'A'O from the attachment position of the trial weight. In this way, the balance calculation unit 21 obtains the weight and attachment position of the correction weight based on the vibration vector OA' and the effect vector A'B'. Note that the arrow between point A' and point O in Figure 17 indicates how the tip of the vibration vector is moved closer to point O from point A' when the correction weight is attached.

[0082] The rotational balancing device 20 can reduce unbalance vibration by determining the weight of the correction weight and the installation position of the correction weight based on a first vibration vector and an effect vector represented by the difference between a second vibration vector and the first vibration vector. The rotational balancing device 20 determines the weight of the correction weight and the installation position of the correction weight based on a first vibration vector corresponding to an estimated critical speed and an effect vector represented by the difference between a second vibration vector corresponding to the estimated critical speed and the first vibration vector corresponding to the estimated critical speed, thereby eliminating the need to repeatedly adjust the weight of the correction weight and the installation position of the correction weight. In this way, the rotational balancing device 20 determines the weight of the correction weight and the installation position of the correction weight through calculations that incorporate the estimated critical speed, thereby enabling more efficient adjustments to reduce unbalance vibration than conventional field balancing.

[0083] According to the second embodiment, the rotational balance adjustment device 20 has the same configuration as the vibration characteristics estimation device 10 according to the first embodiment, and can thereby accurately estimate the critical speed of the rotating shaft 2. This allows the rotational balance adjustment device 20 to effectively perform adjustments to reduce unbalance vibrations.

[0084] Embodiment 3 FIG. 18 is a diagram showing an example of the configuration of a rotational balance adjustment device 30 according to the third embodiment. The rotational balance adjustment device 30 is a device that performs calculations to correct imbalance in a rotating body. In addition to the same configuration as the rotational balance adjustment device 20 according to the second embodiment, the rotational balance adjustment device 30 also includes a model storage unit 31 and a calculation unit 32. FIG. 18 shows the rotational balance adjustment device 30 and a system 1 whose imbalance is to be corrected. In the third embodiment, the same components as those in the first or second embodiment are designated by the same reference numerals, and the following mainly describes the configuration that differs from the first or second embodiment.

[0085] Rotational balance adjustment device 30 includes a signal collection unit 11, an optimization calculation unit 12, an open-loop transfer function calculation unit 13, an estimation unit 14, and a balance calculation unit 21, which are configured similarly to rotational balance adjustment device 20 shown in Fig. 15. Rotational balance adjustment device 30 also includes a model storage unit 31 that stores a calculation model of a vibration vector, and a calculation unit 32 that executes calculations to determine a first vibration vector and a second vibration vector. The calculation unit 32 includes a model update unit 33 that corrects the calculation model, and a vibration vector calculation unit 34 that calculates the first vibration vector and the second vibration vector.

[0086] The model update unit 33 corrects the deviation of the calculation model from the vibration vector corresponding to the critical speed estimated from the operating data. The vibration vector calculation unit 34 calculates a first vibration vector based on the corrected calculation model. The vibration vector calculation unit 34 also calculates a second vibration vector by applying the conditions for when a test weight is attached to the corrected calculation model. The balance calculation unit 21 determines the weight and attachment position of the correction weight based on the first vibration vector calculated by the vibration vector calculation unit 34 and an effect vector represented by the difference between the second vibration vector and the first vibration vector.

[0087] Next, a description will be given of the processing performed by the rotational balance adjustment device 30. Fig. 19 is a flowchart showing the procedure of the processing performed by the rotational balance adjustment device 30 according to the third embodiment.

[0088] In step S21, the signal collector 11 acquires operating data indicating the vibration vector and the rotation speed detected when the rotating shaft 2 without the test weight attached is rotated. The signal collector 11 acquires operating data when the rotating shaft 2 is rotating at the first rotation speed and operating data when the rotating shaft 2 is rotating at the second rotation speed, similar to the case of acquiring the first operating data in step S11 shown in Fig. 16 .

[0089] In step S22, the rotational balance adjustment device 30 estimates a critical speed by processing the operating data acquired in step S21, and determines a vibration vector corresponding to the estimated critical speed. The optimization calculation unit 12 searches for an optimal equivalent mass based on the operating data by processing similar to step S2 shown in FIG. 2. The open-loop transfer function calculation unit 13 calculates an open-loop transfer function by processing similar to step S3 shown in FIG. 2. The estimating unit 14 estimates the critical speed of the rotating shaft 2 by processing similar to step S4 shown in FIG. 2. Furthermore, the estimating unit 14 determines a vibration vector corresponding to the estimated critical speed. The estimating unit 14 outputs information on the determined vibration vector to the model update unit 33.

[0090] In step S23, the model update unit 33 corrects the calculation model so that the vibration vector obtained from the calculation model coincides with the vibration vector corresponding to the critical speed estimated from the operation data. The calculation model includes a parameter representing the stiffness of the system 1. The model update unit 33 corrects the calculation model by correcting the value of the parameter representing the stiffness. The model update unit 33 outputs the corrected calculation model to the vibration vector calculation unit 34.

[0091] In step S24, the vibration vector calculation unit 34 calculates a first vibration vector based on the calculation model corrected in step S23. The vibration vector calculation unit 34 outputs information on the first vibration vector to the balance calculation unit 21.

[0092] In step S25, the vibration vector calculation unit 34 calculates a second vibration vector by applying the conditions when a test weight is attached to the rotating shaft 2 to the corrected calculation model. In the second embodiment, the rotational balance adjustment device 20 acquires second operating data by actually rotating the rotating shaft 2 to which the test weight is attached, and calculates a second vibration vector corresponding to the critical speed estimated based on the second operating data. Instead of the processing in the second embodiment, the rotational balance adjustment device 30 according to the third embodiment calculates the second vibration vector by calculation in the vibration vector calculation unit 34. The vibration vector calculation unit 34 outputs information about the second vibration vector to the balance calculation unit 21.

[0093] In step S26, the balance calculation unit 21 determines the weight of the correcting weight and the installation position of the correcting weight based on the ratio between the first vibration vector and the effect vector represented by the difference between the second vibration vector and the first vibration vector, and the angle between the first vibration vector and the effect vector. Similarly to step S15 shown in FIG. 16, the balance calculation unit 21 determines the weight of the correcting weight based on the ratio between the first vibration vector and the effect vector represented by the difference between the second vibration vector and the first vibration vector. Similarly to step S15 shown in FIG. 16, the balance calculation unit 21 determines the installation position of the correcting weight based on the angle between the first vibration vector and the effect vector represented by the difference between the second vibration vector and the first vibration vector. Thus, the rotational balance adjustment device 30 ends the processing according to the procedure shown in FIG. 19.

[0094] Next, we will explain how to correct the imbalance by attaching a correcting weight based on the calculation results of the rotational balance adjustment device 30. Fig. 20 is a diagram for explaining how to correct the imbalance by attaching a correcting weight in accordance with the calculation results of the rotational balance adjustment device 30 according to the third embodiment. Fig. 20 shows a Nyquist diagram that represents the locus of the tip of the vibration vector when the rotation speed of the rotating shaft 2 is changed.

[0095] The signal collecting unit 11 acquires vibration vector OA data and rotational speed data, which are operating data when the rotating shaft 2 without a test weight attached is rotated. The rotational balance adjusting device 30 estimates the critical speed through processing in the optimization calculating unit 12, the open-loop transfer function calculating unit 13, and the estimating unit 14. The estimating unit 14 calculates the vibration vector OA' corresponding to the estimated critical speed.

[0096] In Figure 20, point O, which is the origin, represents a state where the rotational speed is 0, i.e., a stopped state. Point A' represents the tip of the vibration vector when the rotating shaft 2 without a test weight attached is rotated at a critical speed. Point a' represents the tip of the vibration vector obtained from the calculation model before correction when the rotating shaft 2 without a test weight attached is rotated at a critical speed. Point a^' represents the tip of the vibration vector obtained from the calculation model after correction when the rotating shaft 2 without a test weight attached is rotated at a critical speed. Point b' represents the tip of the vibration vector obtained from the calculation model after correction when the rotating shaft 2 with a test weight attached is rotated at a critical speed. Point o represents the starting point of the vibration vector obtained from the calculation model. In Figure 20, point o coincides with point O.

[0097] As shown in FIG. 20, it is assumed that the vibration vector oa' determined from the calculation model deviates from the vibration vector OA' corresponding to the estimated critical speed. In this case, the model update unit 33 corrects the calculation model so that the vibration vector oa' determined from the calculation model coincides with the vibration vector OA' corresponding to the estimated critical speed. In this way, the model update unit 33 corrects the deviation of the calculation model from the vibration vector OA' corresponding to the critical speed estimated from the operating data. The model update unit 33 calculates a stiffness value such that the vibration vector oa' coincides with the vibration vector OA' by calculation using a method such as the least squares method. The model update unit 33 corrects the calculation model by reflecting the result of the stiffness value determination in the calculation model. The vibration vector calculation unit 34 calculates the vibration vector oa^', which is a first vibration vector, based on the corrected calculation model.

[0098] The vibration vector calculation unit 34 calculates the vibration vector ob', which is the second vibration vector when a test weight is attached to the rotating shaft 2, based on the corrected calculation model. The rotational balance adjustment device 30 according to the third embodiment can determine the second vibration vector without actually rotating the rotating shaft 2 to which the test weight is attached. The arrow between points a^' and b' in Figure 20 shows how the tip of the vibration vector changes from point a^' to point b' when a test weight is attached, and represents the effect vector a^'b'.

[0099] The balance calculation unit 21 calculates the weight of the correction weight by multiplying the weight of the trial weight by |oa^'| / |a^'b'|. The balance calculation unit 21 determines the installation position of the correction weight to be a position shifted by ∠b'a^'o from the installation position of the trial weight. In this way, the balance calculation unit 21 calculates the weight and installation position of the correction weight based on the vibration vector oa^' and the effect vector a^'b'. Note that the arrow between point a^' and point o in Figure 20 shows how the tip of the vibration vector is moved closer to point o from point a^' by installing the correction weight.

[0100] The rotational balancing device 30 can reduce unbalance vibration by determining the weight of the correction weight and the mounting position of the correction weight based on a first vibration vector and an effect vector represented by the difference between a second vibration vector and the first vibration vector. The rotational balancing device 30 determines the weight of the correction weight and the mounting position of the correction weight based on a first vibration vector corresponding to an estimated critical speed and an effect vector represented by the difference between a second vibration vector corresponding to the estimated critical speed and the first vibration vector corresponding to the estimated critical speed, thereby eliminating the need to repeatedly adjust the weight of the correction weight and the mounting position of the correction weight. In this way, the rotational balancing device 30 determines the weight of the correction weight and the mounting position of the correction weight through calculations that incorporate the estimated critical speed, thereby enabling more efficient adjustments to reduce unbalance vibration than conventional field balancing.

[0101] According to the third embodiment, the rotational balance adjustment device 30 has a configuration similar to that of the vibration characteristics estimation device 10 according to the first embodiment, thereby enabling accurate estimation of the critical speed of the rotating shaft 2. Because the rotational balance adjustment device 30 calculates the second vibration vector based on the corrected calculation model, it can determine the second vibration vector corresponding to the estimated critical speed without actually rotating the rotating shaft 2 with a test weight attached to obtain operating data. This allows the rotational balance adjustment device 30 to improve the efficiency of work to reduce unbalance vibration. Furthermore, the rotational balance adjustment device 30 can improve the accuracy of the calculation model based on actual measurement results by correcting the calculation model based on operating data obtained by actually rotating the rotating shaft 2 without a test weight attached. The high accuracy of the calculation model enables the rotational balance adjustment device 30 to perform high-precision adjustments to reduce unbalance vibration. As described above, the rotational balance adjustment device 30 achieves the effect of efficiently and highly accurately performing adjustments to reduce unbalance vibration.

[0102] Next, a hardware configuration for realizing the vibration characteristics estimation device 10 according to the first embodiment and a hardware configuration for realizing the rotational balance adjustment devices 20 and 30 according to the second and third embodiments will be described. Each of the vibration characteristics estimation device 10, the rotational balance adjustment device 20, and the rotational balance adjustment device 30 is realized by a processing circuit. The processing circuit may be a circuit in which a processor executes software, or may be a dedicated circuit.

[0103] When the processing circuit is realized by software, the processing circuit is, for example, a control circuit shown in Fig. 21. Fig. 21 is a diagram showing a configuration example of a control circuit 50 according to embodiments 1 to 3. The control circuit 50 includes an input unit 51, a processor 52, a memory 53, and an output unit 54.

[0104] The input unit 51 is an interface circuit that receives data input from outside the control circuit 50 and provides it to the processor 52. The output unit 54 is an interface circuit that sends data from the processor 52 or the memory 53 to outside the control circuit 50. When the processing circuit is the control circuit 50 shown in FIG. 21 , the processor 52 reads and executes programs stored in the memory 53 to implement each component of the vibration characteristics estimation device 10, the rotational balance adjustment device 20, or the rotational balance adjustment device 30. The programs stored in the memory 53 correspond to each component of the vibration characteristics estimation device 10, the rotational balance adjustment device 20, or the rotational balance adjustment device 30. The processor 52 also outputs data such as calculation results to the volatile memory of the memory 53. The memory 53 is also used as a temporary memory for each process performed by the processor 52. The processor 52 may output data such as calculation results to the memory 53 for storage, or may store the data such as calculation results in an auxiliary storage device via the volatile memory of the memory 53. The function of storing information in each component is implemented by the memory 53 or the auxiliary storage device.

[0105] The processor 52 is a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, or a DSP (Digital Signal Processor). The memory 53 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), or an EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disc).

[0106] Fig. 21 shows an example of hardware in which each component of the vibration characteristics estimation device 10, the rotational balance adjustment device 20, or the rotational balance adjustment device 30 is realized by a general-purpose processor 52 and memory 53. Each component of the vibration characteristics estimation device 10, the rotational balance adjustment device 20, or the rotational balance adjustment device 30 may be realized by a dedicated hardware circuit. Fig. 22 is a diagram showing an example of the configuration of a dedicated hardware circuit 55 according to the first to third embodiments.

[0107] The dedicated hardware circuit 55 includes an input unit 51, an output unit 54, and a processing circuit 56. The processing circuit 56 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a circuit that is a combination of these. Note that each component may be realized by combining the control circuit 50 and the hardware circuit 55. A program corresponding to each component of the vibration characteristics estimation device 10, the rotational balance adjustment device 20, or the rotational balance adjustment device 30 may be provided in a form written on a storage medium such as a CD (Compact Disc)-ROM or a DVD-ROM, or may be provided via a communication line.

[0108] The configurations shown in the above embodiments are examples of the contents of the present disclosure. The configurations of each embodiment can be combined with other known technologies. The configurations of each embodiment can also be combined as appropriate. Part of the configuration of each embodiment can be omitted or modified without departing from the gist of the present disclosure. [Explanation of symbols]

[0109] 1 System, 2 Rotating shaft, 3 Bearing, 4 Vibration sensor, 5 Rotation sensor, 10 Vibration characteristic estimation device, 11 Signal collection unit, 12 Optimization calculation unit, 13 Open loop transfer function calculation unit, 14 Estimation unit, 20, 30 Rotation balance adjustment device, 21 Balance calculation unit, 31 Model storage unit, 32 Calculation unit, 33 Model update unit, 34 Vibration vector calculation unit, 50 Control circuit, 51 Input unit, 52 Processor, 53 Memory, 54 Output unit, 55 Hardware circuit, 56 Processing circuit.

Claims

1. an acquisition unit that acquires operational data including data on vibration vectors of a system having a rotating shaft and a bearing that rotatably supports the rotating shaft, detected when the rotating shaft is rotated, and data on the rotation speed of the rotating shaft when the vibration vector is detected; an optimization calculation unit that, with an equivalent mass of the rotating shaft as a variable, expresses an open-loop transfer function of the system using the equivalent mass and the vibration vector, and, for a first rotational speed and a second rotational speed that are two rotational speeds at which a rate of increase of the vibration vector is positive, calculates an evaluation function that represents an absolute value of a difference between a gain gradient of the open-loop transfer function at the first rotational speed and a gain gradient of the open-loop transfer function at the second rotational speed, and calculates an optimal equivalent mass that is the equivalent mass when the evaluation function is minimum; an estimation unit that estimates a critical speed of the rotating shaft based on the open-loop transfer function determined based on the optimal equivalent mass and the detected vibration vector; A vibration characteristic estimation device comprising:

2. 2. The vibration characteristics estimation device according to claim 1, wherein the evaluation function represents the absolute value of the difference between a gain gradient of the open-loop transfer function at the first rotational speed and a gain gradient of the open-loop transfer function at the second rotational speed, using the equivalent mass as a variable and the vibration vector detected when the rotational speed is the first rotational speed and the vibration vector and the equivalent mass detected when the rotational speed is the second rotational speed.

3. 3. The vibration characteristics estimation device according to claim 1, wherein the rate of increase of the vibration vector at each of the first rotation speed and the second rotation speed is equal to or less than a preset value.

4. an acquisition unit that acquires operational data including data on vibration vectors of a system having a rotating shaft and a bearing that rotatably supports the rotating shaft, detected when the rotating shaft is rotated, and data on the rotation speed of the rotating shaft when the vibration vector is detected; an optimization calculation unit that, with an equivalent mass of the rotating shaft as a variable, expresses an open-loop transfer function of the system using the equivalent mass and the vibration vector, and, for a first rotational speed and a second rotational speed that are two rotational speeds at which a rate of increase of the vibration vector is positive, calculates an evaluation function that represents an absolute value of a difference between a gain gradient of the open-loop transfer function at the first rotational speed and a gain gradient of the open-loop transfer function at the second rotational speed, and calculates an optimal equivalent mass that is the equivalent mass when the evaluation function is minimum; an estimation unit that estimates a critical speed of the rotating shaft based on the open-loop transfer function determined based on the optimal equivalent mass and the detected vibration vector; a balance calculation unit that determines the weight of a correction weight attached to the system and the attachment position of the correction weight by calculation incorporating the estimated critical speed; A rotational balance adjustment device comprising:

5. The vibration vector corresponding to the critical speed when the rotating shaft is rotated without a test weight attached thereto is defined as a first vibration vector, and the vibration vector corresponding to the critical speed when the rotating shaft is rotated with the test weight attached thereto is defined as a second vibration vector, 5. The rotational balance adjustment device according to claim 4, wherein the balance calculation unit determines the weight of the correction weight and the mounting position of the correction weight based on the ratio of the first vibration vector to an effect vector represented by the difference between the second vibration vector and the first vibration vector, and the angle between the first vibration vector and the effect vector.

6. The acquisition unit acquires first operating data indicating the vibration vector and the rotation speed detected when the rotating shaft to which the test weight is not attached is rotated, and second operating data indicating the vibration vector and the rotation speed detected when the rotating shaft to which the test weight is attached is rotated, 6. The rotational balance adjustment device according to claim 5, wherein the balance calculation unit determines the weight of the correcting weight and the mounting position of the correcting weight based on the first vibration vector corresponding to the critical speed estimated from the first operating data, and an effect vector represented by the difference between the second vibration vector corresponding to the critical speed estimated from the second operating data and the first vibration vector corresponding to the critical speed estimated from the first operating data.

7. a model storage unit that stores a calculation model of the vibration vector; A model update unit that corrects the calculation model, the acquisition unit acquires operation data indicating the vibration vector and the rotation speed detected when the rotation shaft to which the test weight is not attached is rotated, the model update unit corrects a deviation of the calculation model from the vibration vector corresponding to the critical speed estimated from the driving data; The rotational balance adjustment device described in claim 5, characterized in that the balance calculation unit determines the weight of the correction weight and the mounting position of the correction weight based on an effect vector represented by the difference between the first vibration vector calculated based on the corrected calculation model, the second vibration vector calculated by applying the conditions when the trial weight is attached to the corrected calculation model, and the first vibration vector calculated based on the corrected calculation model.

8. the computational model includes a parameter representing the stiffness of the system; 8. The rotational balance adjusting device according to claim 7, wherein the model update unit corrects the calculation model by correcting the value of the parameter representing the stiffness.

9. a step of acquiring operation data including data on vibration vectors of a system having a rotating shaft and a bearing that rotatably supports the rotating shaft, the data being detected when the rotating shaft is rotated, and data on the rotation speed of the rotating shaft when the vibration vector is detected; a step of expressing an open-loop transfer function of the system using the equivalent mass of the rotating shaft as a variable, the equivalent mass, and the vibration vector, and calculating an evaluation function that represents an absolute value of a difference between a gain gradient of the open-loop transfer function at a first rotational speed and a gain gradient of the open-loop transfer function at a second rotational speed, the first rotational speed and a second rotational speed being two rotational speeds at which a rate of increase of the vibration vector is positive; a step of searching for an optimal equivalent mass, which is the equivalent mass when the evaluation function is minimized; estimating a critical speed of the rotating shaft based on the open-loop transfer function determined based on the optimal equivalent mass and the detected vibration vector; A vibration characteristic estimation method comprising:

10. a step of acquiring operation data including data on vibration vectors of a system having a rotating shaft and a bearing that rotatably supports the rotating shaft, the data being detected when the rotating shaft is rotated, and data on the rotation speed of the rotating shaft when the vibration vector is detected; a step of expressing an open-loop transfer function of the system using the equivalent mass of the rotating shaft as a variable, the equivalent mass, and the vibration vector, and calculating an evaluation function that represents an absolute value of a difference between a gain gradient of the open-loop transfer function at a first rotational speed and a gain gradient of the open-loop transfer function at a second rotational speed, the first rotational speed and a second rotational speed being two rotational speeds at which a rate of increase of the vibration vector is positive; a step of searching for an optimal equivalent mass, which is the equivalent mass when the evaluation function is minimized; estimating a critical speed of the rotating shaft based on the open-loop transfer function determined based on the optimal equivalent mass and the detected vibration vector; determining a weight of a correction weight to be attached to the system and an attachment position of the correction weight by calculation incorporating the estimated critical speed; A rotational balance adjustment method comprising:

Images