JP2019144126A - Bearing monitoring device, and rotary machine including the same - Google Patents

Abstract

To provide a bearing monitoring device capable of estimating an occurrence risk of peaky vibration, and provide a rotary machine including this bearing monitoring device.SOLUTION: A bearing monitoring device for monitoring the bearing for supporting a rotation axis includes: a pressure detection member configured to be able to detect the oil film pressure of the lubricating-oil between the inner peripheral surface of a bearing pad and the outer peripheral surface of the rotation axis along the circumferential direction of the rotation axis; and a control unit including a starved angle measurement unit. The starved angle measurement unit measures the starved angle on the basis of the detection result by the pressure detection member. Here, the starved angle shows the range of the circumferential direction of the region in which the lubricating-oil is insufficient between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotation axis. The range is shown by the central angle about the axial line of the rotation axis.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a bearing monitoring device and a rotary machine including the bearing monitoring device.

  In a large rotating machine such as a steam turbine or a compressor, a tilting pad bearing is often used to prevent unstable vibration caused by a bearing such as an oil whip. Conventional tilting pad bearings, for example, have been used in an oil bath state by supplying lubricating oil from the oil filler opening between the pads. Recently, in order to improve performance by reducing bearing loss, a nozzle is used to improve the upstream portion of the pad. A direct lubrication type tilting pad bearing (hereinafter referred to as a direct lubrication bearing) that injects lubricating oil directly onto the rotor is used.

  In direct lubrication bearings, there is a need to reduce the amount of lubrication for further performance improvement, but the risk of unstable vibration of direct lubrication bearings when the amount of lubrication is insufficient due to the reduction in the amount of lubrication has become apparent. When the amount of lubrication is insufficient, the lubricant at the pad inlet is depleted and a region where the lubricant is insufficient (starved region) occurs. (Represented by a central angle centered on the heart). It is considered that an unstable vibration (peaky vibration) that vibrates at the natural frequency of the shaft system may occur due to the change in dynamic characteristics of the bearing.

  Although not related to direct lubrication bearings, the rotational speed of the rotating machine and the load state of the plant are judged, and based on this, the shaft vibration abnormality detection judgment value, the vibration state judgment value, and the process state judgment value are extracted, and the plant Patent Document 1 describes an apparatus that monitors and determines abnormal shaft vibration by comparing vibration and process values with measured data.

JP 2004-169624 A

  Until now, the relationship between the starved region and shaft stability (a damping ratio indicating the ease of damping of rotor vibration) has not been clarified. However, as a result of intensive studies by the inventors, the amount of oil supply is insufficient. By doing so, it became clear that the starved area increased and the attenuation ratio decreased at the same time.

  In view of the above-described circumstances, at least one embodiment of the present disclosure aims to provide a bearing monitoring device capable of estimating the occurrence risk of peaky vibration and a rotary machine including the bearing monitoring device.

(1) A bearing monitoring apparatus according to at least one embodiment of the present invention includes:
A bearing monitoring device for monitoring a bearing for supporting a rotating shaft,
The bearing is
At least one bearing pad provided along a circumferential direction of the rotating shaft;
Comprising at least one nozzle for supplying lubricating oil between the inner peripheral surface of the bearing pad facing the outer peripheral surface of the rotary shaft and the outer peripheral surface of the rotary shaft;
The bearing monitoring device includes:
A pressure detection member configured to detect an oil film pressure of the lubricating oil between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotary shaft along a circumferential direction of the rotary shaft;
And a control unit including a starved angle measurement unit,
The starved angle measuring unit is configured to determine the circumference of the region where the lubricant is insufficient between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotary shaft based on a detection result of the pressure detection member. A starved angle representing the range is measured by a central angle centered on the axis of the rotation axis.

  According to the configuration of (1) above, it can be determined whether or not a region (starved region) where the lubricating oil is insufficient is formed from the measured starved angle, so that the risk of occurrence of peaky vibration can be estimated. .

(2) In some embodiments, in the configuration of (1) above,
The pressure detection member includes a plurality of fixed pressure sensors, and the plurality of fixed pressure sensors are provided on the inner peripheral surface of the bearing pad with a space therebetween along the circumferential direction of the rotating shaft. ing.

  According to the configuration of (2) above, the configuration of the pressure detection member is simplified compared to the case where a pressure sensor is provided on the rotating shaft.

(3) In some embodiments, in the configuration of (1) or (2) above,
The pressure detection member includes at least one rotational pressure sensor, and the at least one rotational pressure sensor is provided on the outer peripheral surface of the rotation shaft.

  According to the configuration of (3) above, the starved angle can be measured more accurately than when a pressure sensor is provided on the bearing pad.

(4) In some embodiments, in any one of the above configurations (1) to (3),
The control unit further includes a lubricant supply amount adjusting unit,
Based on the starved angle, the lubricant supply amount adjusting unit adjusts the supply amount of the lubricant supplied from the nozzle between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft.

  According to the configuration of (4) above, when the starved region is formed, the starved region can be reduced by adjusting the supply amount of the lubricating oil, so that the occurrence of peaky vibration can be suppressed.

(5) In some embodiments, in any one of the above configurations (1) to (3),
The controller is
A bearing constant calculator for calculating a bearing constant based on the starved angle;
And a damping ratio estimation unit that estimates a damping ratio that indicates how easily the vibration of the rotating shaft is attenuated based on the bearing constant.

  Depending on the characteristics of the rotary shaft and the bearing, peaky vibration does not occur immediately when the starved region occurs. According to the configuration of (5) above, the bearing characteristics are calculated from the measured starved angle, the damping ratio is estimated using the dynamic model of the shaft system to which the bearing characteristics are input, and based on both the starved angle and the damping ratio. Thus, by estimating the occurrence risk of peaky vibration, the risk of occurrence of peaky vibration caused by the bearing can be estimated more accurately.

(6) In some embodiments, in any one of the above configurations (1) to (3),
A vibration information detecting member for detecting vibration information related to vibration of the rotating shaft;
The control unit further includes an attenuation ratio estimation unit that estimates an attenuation ratio that indicates how easily the vibration of the rotating shaft is attenuated based on the vibration information.

  According to the configuration of (6) above, the damping ratio is estimated from the vibration information related to the vibration of the rotating shaft (such as the displacement of the rotating shaft and the speed or acceleration of the displacement), and the generation of peaky vibration based on both the starved angle and the damping ratio By estimating the risk, the estimation of the risk of occurrence of peaky vibration caused by the bearing becomes more accurate.

(7) In some embodiments, in any one of the above configurations (1) to (3),
A vibration information detecting member for detecting vibration information related to vibration of the rotating shaft;
The controller is
A bearing constant calculator for calculating a bearing constant based on the starved angle;
And a damping ratio estimation unit that estimates a damping ratio that indicates how easily the vibration of the rotating shaft is attenuated based on both the bearing constant and the vibration information.

  According to the configuration of (7) above, the damping ratio is estimated more accurately by comparing and correcting the damping ratio estimated based on each of the dynamic model inputted with the bearing constant and the actually measured vibration information. In addition, the risk of occurrence of peaky vibration can be estimated more accurately.

(8) In some embodiments, in the above configuration (6) or (7),
A vibrator that applies a vibration force to the rotating shaft (either a stationary side such as a bearing stand or a case where a rotating side can be directly excited using an electromagnetic vibrator or the like) In addition,
The damping ratio estimation unit estimates the damping ratio based on the vibration information obtained from the vibration of the rotating shaft when the vibrator applies the exciting force to the rotating shaft.

  According to the configuration of (8) above, the damping ratio is estimated more accurately by estimating the damping ratio based on vibration information obtained from the vibration of the rotating shaft when the vibrator applies the exciting force to the rotating shaft. A simple attenuation ratio can be measured. As a result, the risk of occurrence of peaky vibration can be estimated more accurately.

(9) In some embodiments, in any one of the above configurations (5) to (8),
The control unit further includes a lubricant supply amount adjusting unit,
Based on the starved angle and the damping ratio, the lubricating oil supply amount adjusting unit supplies the lubricating oil supplied from the nozzle between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft. Adjust.

  According to the configuration of (9) above, the supply amount of lubricating oil is only estimated when there is a high possibility of peaky vibration by estimating the risk of occurrence of peaky vibration due to the bearing based on both the starved angle and the damping ratio. Therefore, it is possible to suppress the deterioration of the performance of the rotating machine due to an increase in the supply amount of the lubricating oil without the occurrence of peaky vibration.

(10) A rotating machine according to at least one embodiment of the present invention includes:
A rotation axis;
A bearing for supporting the rotating shaft, at least one bearing pad provided along a circumferential direction of the rotating shaft, an inner peripheral surface of the bearing pad facing an outer peripheral surface of the rotating shaft, and the A bearing provided with at least one nozzle for supplying lubricating oil between the outer peripheral surface of the rotary shaft;
The bearing monitoring device according to any one of (1) to (9) is provided.

  According to the configuration of (10) above, it is possible to estimate the risk of occurrence of peaky vibration due to the bearing in the rotary machine.

  According to at least one embodiment of the present disclosure, it is possible to determine whether or not a region (starved region) in which the lubricating oil is insufficient is formed from the measured starved angle, and thus the risk of occurrence of peaky vibration is estimated. be able to.

FIG. 3 is a schematic configuration diagram of a rotating machine according to Embodiment 1 of the present disclosure. It is a lineblock diagram of a bearing monitoring device concerning Embodiment 1 of this indication. In the bearing monitoring device according to the first embodiment of the present disclosure, it is a schematic diagram illustrating a filling state of lubricating oil in a gap between a rotating shaft and a bearing pad. In the bearing monitoring device concerning Embodiment 1 of this indication, it is a graph which shows an example of the detection value by a pressure detection member. It is a lineblock diagram of a bearing monitoring device concerning Embodiment 2 of this indication. In the bearing monitoring device concerning Embodiment 2 of this indication, it is a graph which shows an example of the detection value by a pressure detection member. It is a structure schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 3 of this indication. It is a block diagram of the structure of the bearing monitoring apparatus which concerns on Embodiment 4 of this indication. It is a block diagram of the structure of the bearing monitoring apparatus which concerns on Embodiment 5 of this indication. It is a structure schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 6 of this indication.

  Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the following embodiments are not merely intended to limit the scope of the present invention, but are merely illustrative examples.

(Embodiment 1)
As shown in FIG. 1, a rotary machine 1 such as a steam turbine or a compressor includes a rotary shaft 2, a rotor 3 fixed to the rotary shaft 2, and a bearing 4 that supports the rotary shaft 2. As shown in FIG. 2, the bearing 4 includes two bearing pads 11, 11 facing the rotating shaft 2 from the lower side in the vertical direction of the rotating shaft 2, and each bearing pad 11 facing the outer peripheral surface 2 a of the rotating shaft 2. The nozzle 12 for supplying lubricating oil to each clearance gap 5 formed between the inner peripheral surface 11a of this and the outer peripheral surface 2a of the rotating shaft 2 is provided. Each nozzle 12 is connected to an oil supply pipe 13 through which lubricating oil flows, and the oil supply pipe 13 is provided with an oil supply pump 14.

  The rotating machine 1 further includes a bearing monitoring device 10 that monitors the bearing 4. The bearing monitoring device 10 includes a control unit 20 and a pressure detection member 30 configured to be able to detect the oil film pressure of the lubricating oil in each gap 5 along the circumferential direction of the rotary shaft 2. The pressure detection member 30 includes three fixed pressure sensors 31, 32 and 33. The fixed pressure sensors 31, 32, and 33 are provided on the inner peripheral surface 11 a of each bearing pad 11 with a space between each other along the circumferential direction of the rotary shaft 2.

  The control unit 20 includes a starved angle measuring unit 21 and a lubricating oil supply amount adjusting unit 22. The starved angle measuring unit 21 and the lubricant supply amount adjusting unit 22 are electrically connected to each other. The fixed pressure sensors 31, 32, and 33 are electrically connected to the starved angle measurement unit 21, respectively. The oil supply pump 14 is electrically connected to the lubricating oil supply amount adjusting unit 22. The starved angle measuring unit 21 is configured to measure a starved angle, which will be described later, based on a detection value by the pressure detection member 30. Based on the starved angle measured by the starved angle measuring unit 21, the lubricating oil supply amount adjusting unit 22 adjusts the operating condition of the oil supply pump 14 in order to adjust the amount of lubricating oil supplied to each gap 5. It is configured to issue a command.

Next, the operation of the bearing monitoring apparatus 10 according to the first embodiment will be described.
As shown in FIG. 1, in the rotating machine 1, the rotor 3 rotates as the rotating shaft 2 supported by the bearing 4 rotates. As shown in FIG. 2, the lubricating oil that has passed through the oil supply pipe 13 by the oil supply pump 14 is supplied from each nozzle 12 to each gap 5, and the gap 5 is filled with the lubricating oil. The bearing 4 can support the rotating shaft 2 by the oil film pressure of the lubricating oil in the gap 5.

As shown in FIG. 3, of the both ends of the gap 5 in the circumferential direction of the rotating shaft 2, the end closer to the nozzle 12 is defined as the proximal end 5 a of the gap 5, and the proximal end in the circumferential direction of the rotating shaft 2. The end of the gap 5 facing the 5a is defined as the distal end 5b of the gap 5. The range in which the rotating shaft 2 can be supported by the oil film pressure of the lubricating oil 15 in the gap 5 in the circumferential direction of the rotating shaft 2 is represented by a pad tension angle that is a central angle with the axis L of the rotating shaft 2 as the center. If the circumferential direction in the lubricating oil 15 from the proximal end 5a to the distal end 5b of the rotary shaft 2 is filled into the gap 5, the pad tension angle is maximum theta _0.

On the other hand, during operation of the rotary machine 1, a region where the lubricating oil 15 is insufficient, that is, a starved region SR may be formed in the vicinity of the proximal end 5 a of the gap 5. A range in the circumferential direction of the rotation axis 2 of the starved region SR is represented by a starved angle θ _S that is a central angle centering on the axis L of the rotation axis 2 starting from the proximal end 5a. In this case, the pad tension angle is θ ₁ (= θ ₀ −θ _S ), which is smaller than the case where the pad tension angle is θ _0. Therefore, when the starved region SR is formed, the dynamic characteristics of the bearing 4 change. Thus, unstable vibration (peaky vibration) that vibrates at the natural frequency of the shaft system may occur.

In the first embodiment, the starved angle θ _S is measured based on the detection value by the pressure detection member 30. For example, as shown in FIG. 3, three fixed pressure sensors 31, 32, 33 are provided in this order along the direction from the proximal end 5 a to the distal end 5 b of the gap 5. Assume that the pressure sensors 31 and 32 are located in the starved region SR, and one fixed pressure sensor 33 is located in the region filled with the lubricating oil 15. In this case, if the change over time of the detection value of each fixed pressure sensor is shown in FIG. 4, the detection value of each of the fixed pressure sensors 31 and 32 located in the starved region SR changes substantially to zero, whereas the lubricant 15 The fixed pressure sensor 33 located in the region filled with the oil pressure detects the oil film pressure of the lubricating oil 15 greater than zero.

As shown in FIG. 3, the starved region SR has a fixed pressure sensor 32 and a fixed pressure sensor 33 from the proximal end 5 a in the circumferential direction of the rotation shaft 2 as shown in FIG. It turns out that it is the range to the position between. In this case, the starved angle measuring unit 21 (see FIG. 2) of the control unit 20 sets, for example, a range from the proximal end 5a to the fixed pressure sensor 32 as a starved angle, or from the proximal end 5a to the fixed pressure sensor 33. The range is the starved angle, the range from the proximal end 5a to the intermediate position between the fixed pressure sensor 32 and the fixed pressure sensor 33 is the starved angle, or the starved angle is determined by other methods. be able to. In any of these examples, there is a slight deviation from the actual starved angle θ _S. This shift can be reduced by increasing the number of fixed pressure sensors to reduce the distance between them.

  By the way, the relationship between the starved region and the shaft system stability, in particular, the relationship between the starved angle and the damping ratio representing the ease of damping of the vibration of the rotating shaft has not been clear so far. In order to clarify this relationship, the present inventors tend to increase the starved region (increase the starved angle) when the supply amount of lubricating oil decreases by performing an element test using a model rotor of Φ200. It became clear that the damping ratio tends to decrease as the starved angle increases. Then, since the risk of occurrence of peaky vibration increases as the starved angle increases, it is considered that the risk of occurrence of peaky vibration can be reduced by increasing the supply amount of lubricating oil and decreasing the starved angle.

Therefore, in the first embodiment, as illustrated in FIG. 2, an upper limit value of the starved angle is set in advance in the lubricant supply amount adjusting unit 22 of the control unit 20. Based on the relationship between the starved angle and the damping ratio obtained from the element tests of the present inventors, a starved angle corresponding to the lower limit value of the damping ratio at which peaky vibration can occur is obtained, and this is defined as the upper limit value of the starved angle. To do. In the above operation, the starved angle measuring unit 21 measures the starved angle θ _S , and the lubricating oil supply amount adjusting unit 22 compares the measured starved angle θ _S with a preset upper limit value of the starved angle, If the former is smaller than the latter, it is determined that the possibility of peaky vibration is low. On the other hand, when the former is greater than or equal to the latter, the lubricating oil supply amount adjusting unit 22 determines that there is a high possibility that peaky vibration will occur, and determines an increase in the amount of lubricating oil supplied to the gap 5.

When the lubricating oil supply amount adjustment unit 22 determines to increase the supply amount of the lubricating oil to the gap 5, the lubricating oil supply amount adjustment unit 22 sends an instruction to increase the supply amount to the oil supply pump 14 to operate the oil supply pump 14. Adjust the conditions. In this case, the relationship between the starved angle θ _S and the supply amount of the lubricating oil may be determined in advance and adjusted to the supply amount based on the relationship, or the change in the starved angle θ _S caused by increasing the supply amount may be adjusted. The supply amount may be obtained in real time from the starved angle measuring unit 21 and the supply amount may be feedback controlled based on the starved angle θ _S. As the supply amount of the lubricating oil increases, the starved region SR (see FIG. 3) is reduced (the starved angle is reduced), so that the risk of occurrence of peaky vibration can be reduced.

Thus, since it can be determined from the measured starved angle θ _S whether or not a starved region is formed, the risk of occurrence of peaky vibration can be estimated. When the starved region is formed, the starved region is reduced by adjusting the supply amount of the lubricating oil, so that the occurrence of peaky vibration can be suppressed.

  In the first embodiment, the pressure detection member 30 includes the three fixed pressure sensors 31, 32, and 33. However, the number is not limited to three. As described above, if the number of fixed pressure sensors is increased, the measurement accuracy of the starved angle is increased. Therefore, the pressure detection member 30 may have an arbitrary number of four or more fixed pressure sensors. For example, the pressure detection member 30 may be configured by two fixed pressure sensors.

(Embodiment 2)
Next, a bearing monitoring apparatus according to the second embodiment will be described. The bearing monitoring apparatus according to the second embodiment is obtained by changing the configuration of the pressure detection member with respect to the first embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the bearing monitoring apparatus 10 according to the second embodiment includes a control unit 20 and a pressure including one rotational pressure sensor 35 configured to be able to detect the oil film pressure of the lubricating oil in each gap 5. And a detection member 30. The rotational pressure sensor 35 is provided on the outer peripheral surface 2 a of the rotary shaft 2 and rotates together with the rotary shaft 2. The detection value of the rotational pressure sensor 35 can be transmitted to the starved angle measurement unit 21 of the control unit 20. In order to transmit the detection value of the rotational pressure sensor 35 to the starved angle measurement unit 21, for example, a telemeter may be installed and the detection value may be transmitted wirelessly to the starved angle measurement unit 21. An electric wire connected to the starved angle measuring unit 21 via a slip ring provided at the end of the rotating shaft 2, extending to the shaft end along the length direction in the rotating shaft 2. It is good also as a structure electrically connected. Other configurations are the same as those of the first embodiment.

Also in the second embodiment, the operation of adjusting the supply amount of the lubricating oil based on the measured starved angle θ _S is the same as that of the first embodiment. For this reason, as in the first embodiment, the risk of occurrence of peaky vibration can be estimated, and when the starved region SR is formed, the starved region SR can be reduced by adjusting the supply amount of the lubricating oil. Generation of vibration can be suppressed.

In the second embodiment, since the pressure detection member 30 is constituted by one rotational pressure sensor 35 provided on the outer peripheral surface 2a of the rotary shaft 2, the operation of detecting the oil film pressure of the lubricating oil 15 in the gap 5 is performed. Unlike the first embodiment, as a result, the measurement operation of the starved angle θ _S is different from the first embodiment. Since the rotational pressure sensor 35 rotates together with the rotary shaft 2, the rotary pressure sensor 35 enters the gap 5 from the proximal end 5a, moves through the gap 5 in the circumferential direction of the rotary shaft 2, and exits the gap 5 from the distal end 5b. During this time, the rotational pressure sensor 35 detects the oil film pressure. For example, if a sensor that acquires a rotation pulse of the rotation shaft 2 is used, the position of the rotation pressure sensor 35 in the circumferential direction of the rotation shaft 2 can be specified while the rotation pressure sensor 35 rotates together with the rotation shaft 2.

When the position in the circumferential direction of the rotating shaft 2 is expressed by an angular position with the axis L of the rotating shaft 2 as the center, a graph of a detection value by the rotational pressure sensor 35 with respect to this angular position is as shown in FIG. Assuming that the angular positions of the proximal end 5a and the distal end 5b of the gap 5 are α _5a and α _5b , respectively, and the starved region SR having the starved angle θ _S is formed in the gap 5, the detection value by the rotational pressure sensor 35 is detected. , The angular range from α _5a to α _S (= α _5a + θ _S ) is almost zero, increases after passing the angular position α _S , takes a maximum value, then turns to decrease, the angular position It becomes zero at α _5b . That is, the range in which the detected value by the rotational pressure sensor 35 from the angular position α _5a is zero is a starved region, and the starved angle θ _S can be determined by calculating θ _S = α _S −α _5a .

In the second embodiment, since the rotational pressure sensor 35 can continuously measure the oil film pressure of the lubricating oil 15 in the gap 5, a plurality of fixed pressure sensors are provided at intervals as in the first embodiment. As compared with the above, the starved angle θ _S can be accurately measured. However, since the configuration for transmitting the detection value by the rotational pressure sensor 35 to the starved angle measurement unit 21 is complicated as described above, the configuration of the pressure detection member 30 is complicated compared to the first embodiment. In other words, the first embodiment has an effect that the configuration of the pressure detection member 30 is simplified as compared with the second embodiment.

In the second embodiment, the pressure detection member 30 has one rotational pressure sensor 35, but may have two or more rotational pressure sensors 35. In this case, since two or more graphs as shown in FIG. 6 are obtained, a more accurate starved angle θ _S can be measured by calculating the average of the starved angles θ _S obtained from the respective graphs.

  The pressure detection member 30 includes the fixed pressure sensors 31, 32, and 33 of the first embodiment (however, the number is not limited to three and may be two or more) and the rotational pressure sensor 35 of the second embodiment. And both of them may be included.

(Embodiment 3)
Next, a bearing monitoring apparatus according to the third embodiment will be described. The bearing monitoring apparatus according to the third embodiment estimates the damping ratio from the measured starved angle for each of the first and second embodiments, and adjusts the supply amount of the lubricating oil based on both the starved angle and the damping ratio. It is changed as follows. Hereinafter, the third embodiment will be described with a configuration in which the configuration of the first embodiment is changed as described above. However, the third embodiment may be configured by changing the configuration of the second embodiment as described above. Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the bearing monitoring apparatus 10 according to the third embodiment includes a control unit 20 and a pressure detection member 30. The control unit 20 includes a starved angle measuring unit 21 and a lubricating oil supply amount adjusting unit 22, a bearing constant calculating unit 23 electrically connected to the starved angle measuring unit 21, a bearing constant calculating unit 23, and a lubricating oil supply amount adjusting. And an attenuation ratio estimation unit 24 electrically connected to each of the units 22. Other configurations are the same as those of the first embodiment.

  Also in the third embodiment, the pressure detecting member 30 detects the oil film pressure of the lubricating oil in the gap 5, and the operation in which the starved angle measuring unit 21 measures the starved angle based on this detected value is the same as in the first embodiment. is there. In the third embodiment, the bearing constant calculation unit 23 calculates the bearing constant based on the measured starved angle, and the damping ratio estimation unit 24 easily attenuates the vibration of the rotating shaft 2 based on the calculated bearing constant. Is different from the first embodiment in that the lubricating oil supply amount adjusting unit 22 adjusts the supply amount of the lubricating oil based on both the starved angle and the damping ratio. Operations different from those of the first embodiment will be described below.

  The bearing constant calculation unit 23 sets an analysis condition of a bearing analysis model such as thermohydrodynamic lubrication (THL) analysis using the measured starved angle, and calculates the bearing constant. The damping ratio estimation unit 24 inputs the calculated bearing constant into, for example, a dynamic model of a shaft system that is a finite model by beam elements, and performs a shaft system stability calculation on this dynamic model, thereby calculating a damping ratio. presume. In addition, the mechanical model at the time of design of the rotary machine 1 can be used for a dynamic model.

  An upper limit value of the starved angle and a lower limit value of the damping ratio are set in advance in the lubricant supply amount adjusting unit 22. The lubricant supply amount adjusting unit 22 compares the starved angle measured by the starved angle measuring unit 21 with the preset upper limit value of the starved angle, and the damping ratio estimated by the damping ratio estimating unit 24. Then, a preset lower limit value of the attenuation ratio is compared. Lubricating oil supply amount when the starved angle measured by the starved angle measuring unit 21 is equal to or larger than the upper limit value of the starved angle and the damping ratio estimated by the damping ratio estimating unit 24 is equal to or smaller than the lower limit value of the damping ratio. The adjustment unit 22 determines that there is a high possibility of occurrence of peaky vibration, and determines an increase in the amount of lubricating oil supplied to the gap 5. The operation of increasing the supply amount of the lubricating oil is the same as that of the first embodiment.

  Depending on the characteristics of the rotating shaft 2 and the bearing 4, peaky vibration does not occur immediately when the starved region occurs. That is, the sensitivity to the shaft system stability in a state where the lubricating oil is insufficient (starved state) varies depending on the characteristics of the rotary shaft 2 and the bearing 4. For this reason, if the supply amount of the lubricating oil is increased only in accordance with the starved angle, the supply amount of the lubricating oil increases despite the low possibility of occurrence of peaky vibration. There is a risk that performance will deteriorate. However, in Embodiment 3, the damping ratio is estimated from the measured starved angle, and the risk of occurrence of peaky vibration due to the bearing is estimated from both the starved angle and the damping ratio, so that the risk of occurrence of peaky vibration is more accurately determined. Can be estimated.

(Embodiment 4)
Next, a bearing monitoring apparatus according to the fourth embodiment will be described. The bearing monitoring apparatus according to the fourth embodiment estimates the damping ratio from the actual vibration of the rotating shaft 2 for each of the first and second embodiments, and supplies the lubricating oil based on both the starved angle and the damping ratio. Is changed to adjust. In the following, the fourth embodiment will be described with the configuration of the first embodiment changed as described above, but the fourth embodiment may be configured by changing the configuration of the second embodiment as described above. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 8, the bearing monitoring apparatus 10 according to the fourth embodiment includes a control unit 20, a pressure detection member 30, and a vibration information detection member 40 that detects vibration information related to vibration of the rotating shaft 2. Yes. In the following description, the vibration information is described as the displacement of the rotating shaft 2. For this reason, the vibration information detection member 40 is a displacement sensor 40a. However, the vibration information is not limited to the displacement of the rotating shaft 2, and the speed, acceleration, or the like in the direction orthogonal to the axis L of the rotating shaft 2 may be used as the vibration information. In this case, the vibration information detection member is a speed sensor, an acceleration sensor, or the like.

  The control unit 20 includes a starved angle measuring unit 21 and a lubricating oil supply amount adjusting unit 22, and a damping ratio estimating unit 24 electrically connected to each of the displacement sensor 40 a and the lubricating oil supply amount adjusting unit 22. . Other configurations are the same as those of the first embodiment.

  Also in the fourth embodiment, the pressure detection member 30 detects the oil film pressure of the lubricating oil in the gap 5, and the operation in which the starved angle measuring unit 21 measures the starved angle based on this detected value is the same as that of the first embodiment. is there. In the fourth embodiment, based on the displacement of the vibration of the rotation shaft 2 measured by the displacement sensor 40a, the attenuation ratio estimation unit 24 estimates the attenuation ratio indicating the ease of attenuation of the vibration of the rotation shaft 2, and the starved angle The difference from the first embodiment is that the lubricant supply amount adjusting unit 22 adjusts the supply amount of the lubricant based on both the damping ratio and the damping ratio. Operations different from those of the first embodiment will be described below.

  During operation of the rotary machine 1, the displacement sensor 40 a detects the displacement of the vibration of the rotary shaft 2 and transmits the detection result to the attenuation ratio estimation unit 24. The attenuation ratio estimation unit 24 analyzes the frequency of the time history waveform of the detection value detected by the displacement sensor 40a and calculates a frequency spectrum. For example, a fast Fourier transform (FFT) can be used for the calculation of the frequency spectrum. The attenuation ratio estimation unit 24 estimates the attenuation ratio by the half power method, curve fitting, or the like from the sharpness of the peak in the natural frequency of the obtained frequency spectrum.

  The operation in which the lubricant supply amount adjusting unit 22 adjusts the lubricant supply amount based on both the starved angle and the damping ratio is the same as the operation of the third embodiment. For this reason, also in Embodiment 4, the risk of occurrence of peaky vibration can be estimated more accurately by estimating the risk of occurrence of peaky vibration due to the bearing from both the starved angle and the damping ratio.

(Embodiment 5)
Next, a bearing monitoring apparatus according to the fifth embodiment will be described. The bearing monitoring apparatus according to the fifth embodiment estimates the damping ratio from the measured starved angle and estimates the damping ratio from the actual vibration of the rotating shaft 2 with respect to each of the first and second embodiments. By comparing the ratio, a more accurate damping ratio is estimated, and the supply amount of the lubricating oil is changed based on both the starved angle and the damping ratio. Hereinafter, the fifth embodiment will be described with a configuration in which the configuration of the first embodiment is changed as described above, but the fifth embodiment may be configured by changing the configuration of the second embodiment as described above. In the fifth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 9, the bearing monitoring apparatus 10 according to the fifth embodiment includes a control unit 20, a pressure detection member 30, and a vibration information detection member 40 that detects vibration information related to vibration of the rotating shaft 2. Yes. In the fifth embodiment, as in the fourth embodiment, the following description will be made assuming that the vibration information detecting member 40 is the displacement sensor 40a. However, the embodiment is not limited to the displacement sensor 40a, and is the same as the fourth embodiment.

  The control unit 20 includes a starved angle measuring unit 21 and a lubricating oil supply amount adjusting unit 22, a bearing constant calculating unit 23 electrically connected to the starved angle measuring unit 21, a displacement sensor 40 a and a lubricating oil supply amount adjusting unit 22. In addition, a damping ratio estimation unit 24 electrically connected to each of the bearing constant calculation units 23 is included. Other configurations are the same as those of the first embodiment.

  Also in the fifth embodiment, the pressure detecting member 30 detects the oil film pressure of the lubricating oil in the gap 5, and the operation in which the starved angle measuring unit 21 measures the starved angle based on this detected value is the same as in the first embodiment. is there. In the fifth embodiment, the damping ratio estimator 24 is based on both the vibration displacement of the rotating shaft 2 measured by the displacement sensor 40a and the bearing constant calculated by the bearing constant calculator 23 based on the measured starved angle. However, the damping ratio representing the ease of damping of the vibration of the rotating shaft 2 is estimated, and based on both the starved angle and the damping ratio, the lubricating oil supply amount adjusting unit 22 adjusts the lubricating oil supply amount. Different from the first embodiment. Operations different from those of the first embodiment will be described below.

The operation in which the bearing constant calculation unit 23 calculates the bearing constant based on the measured starved angle, and the damping ratio estimation unit 24 estimates the damping ratio based on the calculated bearing constant is the same as that in the third embodiment, and the displacement The operation of the damping ratio estimation unit 24 estimating the damping ratio based on the vibration displacement of the rotating shaft 2 measured by the sensor 40a is the same as that of the fourth embodiment. In the fifth embodiment, the attenuation ratio estimation unit 24 can estimate a more accurate attenuation ratio by comparing and correcting the two attenuation ratios estimated in this way. As an example of this correction method, the analysis value (ζcal) of the damping ratio based on the dynamic model is difficult to reflect the influence of an unknown structural damping (ζstr) or the like in the actual machine, so the actually measured damping ratio (ζexp) It is conceivable to correct the analysis value using
ζcal (after correction) = ζcal + ζstr
ζstr = ζexp0−ζcal0
Here, the subscript 0 means a value under an arbitrary reference condition such as a condition where the supply amount of the lubricating oil is large.

  The operation in which the lubricant supply amount adjusting unit 22 adjusts the lubricant supply amount based on both the starved angle and the damping ratio is the same as the operations in the third and fourth embodiments. For this reason, also in Embodiment 5, the risk of occurrence of peaky vibration can be estimated more accurately by estimating the risk of occurrence of peaky vibration caused by the bearing from both the starved angle and the damping ratio.

(Embodiment 6)
Next, a bearing monitoring apparatus according to the sixth embodiment will be described. The bearing monitoring apparatus according to the sixth embodiment estimates the damping ratio based on the displacement of the vibration of the rotating shaft caused by the vibration generator applying the exciting force to the rotating shaft in each of the fourth and fifth embodiments. It is changed as follows. Hereinafter, the sixth embodiment will be described with a configuration in which the configuration of the fourth embodiment is changed as described above, but the sixth embodiment may be configured by changing the configuration of the fifth embodiment as described above. In the sixth embodiment, the same components as those in the fourth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As illustrated in FIG. 10, the bearing monitoring apparatus 10 according to the sixth embodiment includes a control unit 20, a pressure detection member 30, a vibration information detection member 40 that detects vibration information related to vibration of the rotation shaft 2, and a rotation shaft. 2 is provided with a vibration exciter 50 for applying a vibration force. The vibration exciter 50 is provided, for example, on the bearing base of the bearing 4 and is electrically connected to the damping ratio estimation unit 24 of the control unit 20. Other configurations are the same as those of the fourth embodiment. In the sixth embodiment, as in the fourth embodiment, the following description will be made on the assumption that the vibration information detecting member 40 is the displacement sensor 40a. However, the embodiment is not limited to the displacement sensor 40a.

  Also in the sixth embodiment, the pressure detecting member 30 detects the oil film pressure of the lubricating oil in the gap 5, and the operation in which the starved angle measuring unit 21 measures the starved angle based on the detected value is the same as in the fourth embodiment. is there. In the sixth embodiment, the vibration exciter 50 applies vibration force to the rotary shaft 2 to vibrate the rotary shaft 2, and based on the displacement of the vibration of the rotary shaft 2 measured by the displacement sensor 40a, the damping ratio. The estimation unit 24 is different from the fourth embodiment in that the estimation unit 24 estimates an attenuation ratio that indicates how easily the vibration of the rotating shaft 2 is attenuated. Operations different from the fourth embodiment will be described below.

  The vibrator 50 vibrates the rotating shaft 2 by applying an exciting force to the rotating shaft 2. The value of the excitation force is transmitted to the damping ratio estimation unit 24. In this state, the displacement sensor 40 a detects the displacement of the vibration of the rotating shaft 2 and transmits the detection result to the attenuation ratio estimation unit 24. Similarly to the fourth embodiment, the damping ratio estimation unit 24 performs frequency analysis on the time history waveform of the detection value detected by the displacement sensor 40a to calculate the frequency spectrum, and from the sharpness of the peak at the natural frequency of the obtained frequency spectrum, The attenuation ratio is estimated by the half power method or curve fitting. The operation in which the damping ratio estimation unit 24 estimates the damping ratio is the same as that in the fourth embodiment. However, in the sixth embodiment, the excitation force applied to the rotating shaft 2 is due to the shaker 50. The attenuation ratio can be estimated more accurately than in the case of the fourth embodiment in that the input value is clear.

  The operation in which the lubricant supply amount adjusting unit 22 adjusts the lubricant supply amount based on both the starved angle and the damping ratio is the same as the operation of the fourth embodiment. For this reason, also in Embodiment 6, the risk of occurrence of peaky vibration can be estimated more accurately by estimating the risk of occurrence of peaky vibration caused by the bearing from both the starved angle and the damping ratio.

  In the sixth embodiment, the vibration exciter 50 is provided on the stationary side of the bearing base of the bearing 4 as an example, but is not limited to this configuration. An electromagnetic shaker or the like may be used as the shaker 50 so that the rotation side can be directly excited.

  Each of the bearings 4 of the first to sixth embodiments has the two bearing pads 11 and 11 facing the rotating shaft 2 from the lower side in the vertical direction of the rotating shaft 2, but is not limited to this embodiment. For example, the bearing 4 may be configured to have five bearing pads arranged in a ring shape around the rotation shaft 2. The number of bearing pads is not limited to 2 or 5, and the techniques of the first to sixth embodiments of the present disclosure can be applied to a bearing having at least one bearing pad.

DESCRIPTION OF SYMBOLS 1 Rotating machine 2 Rotating shaft 2a Outer peripheral surface 3 (of rotating shaft) 3 Rotor 4 Bearing 5 Clearance 5a Proximal end 5b (of clearance) Distal end 10 Bearing monitoring device 11 Bearing pad 11a (inside of bearing pad) Peripheral surface 12 Nozzle 13 Oil supply pipe 13
14 Oil supply pump 15 Lubricating oil 20 Control unit 21 Starved angle measuring unit 22 Lubricating oil supply amount adjusting unit 23 Bearing constant calculating unit 24 Attenuation ratio estimating unit 30 Pressure detecting member 31 Fixed pressure sensor 32 Fixed pressure sensor 33 Fixed pressure sensor 35 Rotating pressure Sensor 40 Vibration information detection member 40a Displacement sensor 50 Exciter SR Starved area θ _S Starved angle

Claims (10)

A bearing monitoring device for monitoring a bearing for supporting a rotating shaft,
The bearing is
At least one bearing pad provided along a circumferential direction of the rotating shaft;
Comprising at least one nozzle for supplying lubricating oil between the inner peripheral surface of the bearing pad facing the outer peripheral surface of the rotary shaft and the outer peripheral surface of the rotary shaft;
The bearing monitoring device includes:
A pressure detection member configured to detect an oil film pressure of the lubricating oil between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotary shaft along a circumferential direction of the rotary shaft;
And a control unit including a starved angle measurement unit,
The starved angle measuring unit is configured to determine the circumference of the region where the lubricant is insufficient between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotary shaft based on a detection result of the pressure detection member. A bearing monitoring device that measures a starved angle that is a range of directions and that expresses the range with a central angle centered on the axis of the rotating shaft.   The pressure detection member includes a plurality of fixed pressure sensors, and the plurality of fixed pressure sensors are provided on the inner peripheral surface of the bearing pad with a space therebetween along the circumferential direction of the rotating shaft. The bearing monitoring device according to claim 1.   The bearing monitoring apparatus according to claim 1, wherein the pressure detection member includes at least one rotational pressure sensor, and the at least one rotational pressure sensor is provided on the outer peripheral surface of the rotating shaft. The control unit further includes a lubricant supply amount adjusting unit,
Based on the starved angle, the lubricant supply amount adjusting unit adjusts the supply amount of the lubricant supplied from the nozzle between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft. The bearing monitoring apparatus as described in any one of Claims 1-3. The controller is
A bearing constant calculator for calculating a bearing constant based on the starved angle;
The bearing monitoring apparatus according to any one of claims 1 to 3, further comprising: a damping ratio estimation unit that estimates a damping ratio that represents ease of damping of vibration of the rotating shaft based on the bearing constant. A vibration information detecting member for detecting vibration information related to vibration of the rotating shaft;
4. The control unit according to claim 1, further comprising: an attenuation ratio estimation unit that estimates an attenuation ratio that represents ease of attenuation of the vibration of the rotating shaft based on the vibration information. 5. Bearing monitoring device. A vibration information detecting member for detecting vibration information related to vibration of the rotating shaft;
The controller is
A bearing constant calculator for calculating a bearing constant based on the starved angle;
The damping ratio estimation part which estimates further the damping ratio showing the ease of damping | damping of the vibration of the said rotating shaft based on both the said bearing constant and the said vibration information is any one of Claims 1-3. The bearing monitoring device described. Further comprising a vibrator for applying a vibration force to the rotating shaft;
The damping ratio estimation unit estimates the damping ratio based on the vibration information obtained from vibration of the rotating shaft when the vibrator applies the exciting force to the rotating shaft. Item 6. The bearing monitoring device according to Item 6 or 7. The control unit further includes a lubricant supply amount adjusting unit,
Based on the starved angle and the damping ratio, the lubricating oil supply amount adjusting unit supplies the lubricating oil supplied from the nozzle between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft. The bearing monitoring device according to any one of claims 5 to 8, which adjusts A rotation axis;
A bearing for supporting the rotating shaft, at least one bearing pad provided along a circumferential direction of the rotating shaft, an inner peripheral surface of the bearing pad facing an outer peripheral surface of the rotating shaft, and the A bearing provided with at least one nozzle for supplying lubricating oil between the outer peripheral surface of the rotary shaft;
A rotary machine comprising the bearing monitoring device according to any one of claims 1 to 9.

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