JP6961513B2 - Bearing monitoring device and rotating machine equipped with this bearing monitoring device - Google Patents

Description

The present disclosure relates to a bearing monitoring device and a rotating machine provided with the bearing monitoring device.

In large rotating machines such as steam turbines and compressors, tilting pad bearings are often used to prevent unstable vibration caused by bearings such as oil whips. Conventional tilting pad bearings have been used in an oil bath state by supplying lubricating oil from the oil filler port between the pads, for example, but in recent years, in order to improve performance by reducing bearing loss, a nozzle is used to the upstream part of the pad. Direct lubrication type tilting pad bearings (hereinafter referred to as direct lubrication bearings) that inject lubricating oil directly into the rotor have come to be used.

In direct moisture bearings, it is required to reduce the amount of lubrication in order to further improve the performance. However, due to the reduction in the amount of lubrication, the risk of unstable vibration of the direct moisture bearing when the amount of lubrication is insufficient has become apparent. When the amount of lubrication is insufficient, the lubricating oil at the pad inlet is depleted and a region where the lubricating oil is insufficient (starved region) occurs, and the apparent pad tension angle (the region that supports the rotor in each pad is the shaft of the rotor). (Represented by the central angle centered on the heart) is reduced. It is considered that unstable vibration (peaky vibration) that vibrates at the natural frequency of the shaft system may occur due to such changes in the dynamic characteristics of the bearing.

Although it is not related to direct bearings, the rotation speed of the rotating machine and the load state of the plant are judged, and based on this, the judgment value for detecting shaft vibration abnormality, the vibration state judgment value, and the process state judgment value are taken out and the plant Patent Document 1 describes a device for monitoring and determining abnormal shaft vibration by comparing it with measured data of vibration and process value.

Japanese Unexamined Patent Publication No. 2004-169624

Until now, the relationship between the starved region and the shaft system stability (damping ratio indicating the ease of damping of rotor vibration) has not been clarified, but as a result of diligent studies by the present inventors, the amount of refueling is insufficient. It was clarified that this increased the starved region and at the same time decreased the damping ratio.

In view of the above circumstances, at least one embodiment of the present disclosure is an object of providing a bearing monitoring device capable of estimating the risk of occurrence of peaky vibration and a rotating machine provided with the bearing monitoring device.

(1) The bearing monitoring device according to at least one embodiment of the present invention is
A bearing monitoring device that monitors bearings to support the rotating shaft.
The bearing is
At least one bearing pad provided along the circumferential direction of the rotating shaft, and
It is provided with at least one nozzle for supplying lubricating oil between the inner peripheral surface of the bearing pad facing the outer peripheral surface of the rotating shaft and the outer peripheral surface of the rotating shaft.
The bearing monitoring device is
A pressure detecting member configured to be able to detect the oil film pressure of the lubricating oil between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft along the circumferential direction of the rotating shaft.
Equipped with a control unit including a starved angle measurement unit
Based on the detection result of the pressure detecting member, the starved angle measuring unit has the peripheral surface of the region where the lubricating oil is insufficient between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft. The starved angle, which is a range of directions and represents the range at a central angle centered on the axis of the rotation axis, is measured.

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

(2) In some embodiments, in the configuration of (1) above,
The pressure detecting 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 at intervals along the circumferential direction of the rotating shaft. ing.

According to the configuration of (2) above, the configuration of the pressure detecting member becomes simpler than the case where the pressure sensor is provided on the rotating shaft.

(3) In some embodiments, in the configuration of (1) or (2) above,
The pressure detecting 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.

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

(4) In some embodiments, in any of the configurations (1) to (3) above,
The control unit further includes a lubricating oil supply amount adjusting unit.
Based on the starved angle, the lubricating oil supply amount adjusting unit adjusts the supply amount of 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.

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 of the configurations (1) to (3) above,
The control unit
A bearing constant calculation unit that calculates the bearing constant based on the starved angle, and a bearing constant calculation unit.
A damping ratio estimation unit for estimating a damping ratio representing the ease of damping of the vibration of the rotating shaft based on the bearing constant is further included.

Depending on the characteristics of the rotating shaft and the bearing, peaky vibration may not occur immediately when a 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 in which the bearing characteristics are input, and the damping ratio is estimated based on both the starved angle and the damping ratio. By estimating the risk of peaky vibration, the risk of peaky vibration caused by bearings can be estimated more accurately.

(6) In some embodiments, in any of the configurations (1) to (3) above,
A vibration information detecting member for detecting vibration information related to the vibration of the rotating shaft is further provided.
The control unit further includes a damping ratio estimation unit that estimates a damping ratio indicating the ease of damping of the vibration of the rotating shaft 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 (displacement of the rotating shaft, the speed or acceleration of the displacement, etc.), and the peaky vibration is generated 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 of the configurations (1) to (3) above,
A vibration information detecting member for detecting vibration information related to the vibration of the rotating shaft is further provided.
The control unit
A bearing constant calculation unit that calculates the bearing constant based on the starved angle, and a bearing constant calculation unit.
Further includes a damping ratio estimation unit that estimates a damping ratio indicating the ease of damping of the vibration of the rotating shaft based on both the bearing constant and the vibration information.

According to the configuration of (7) above, the estimation of the damping ratio becomes more accurate by comparing and correcting the damping ratio estimated based on each of the mechanical model in which the bearing constant is input and the measured vibration information. , The risk of peaky vibration can be estimated more accurately.

(8) In some embodiments, in the configuration of (6) or (7) above,
An exciter that applies a vibrating force to the rotating shaft (either when it is installed on the stationary side of a bearing base or when the rotating side can be directly vibrated by using an electromagnetic exciter or the like). Further prepare
The damping ratio estimation unit estimates the damping ratio based on the vibration information obtained from the vibration of the rotating shaft when the vibrating machine applies the exciting force to the rotating shaft.

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

(9) In some embodiments, in any of the configurations (5) to (8) above,
The control unit further includes a lubricating oil 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. To adjust.

According to the configuration of (9) above, by estimating the risk of peaky vibration caused by bearings based on both the starved angle and the damping ratio, the amount of lubricating oil supplied only when there is a high possibility that peaky vibration will occur. Therefore, it is possible to prevent the performance of the rotating machine from deteriorating due to an increase in the amount of lubricating oil supplied even though peaky vibration does not occur.

(10) The rotary machine according to at least one embodiment of the present invention is
Rotation axis and
A bearing for supporting the rotating shaft, at least one bearing pad provided along the circumferential direction of the rotating shaft, an inner peripheral surface of the bearing pad facing the outer peripheral surface of the rotating shaft, and the said. A bearing comprising at least one nozzle for supplying lubricating oil to and from the outer peripheral surface of the rotating shaft.
The bearing monitoring device according to any one of (1) to (9) above is provided.

According to the configuration (10) above, the risk of peaky vibration caused by bearings can be estimated in a rotating machine.

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

It is a structural schematic diagram of the rotary machine which concerns on Embodiment 1 of this disclosure. It is a structural schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 1 of this disclosure. FIG. 5 is a schematic view illustrating a state in which lubricating oil is filled in a gap between a rotating shaft and a bearing pad in the bearing monitoring device according to the first embodiment of the present disclosure. It is a graph which shows an example of the detection value by a pressure detection member in the bearing monitoring apparatus which concerns on Embodiment 1 of this disclosure. It is a structural schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 2 of this disclosure. It is a graph which shows an example of the detection value by a pressure detection member in the bearing monitoring apparatus which concerns on Embodiment 2 of this disclosure. It is a structural schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 3 of this disclosure. It is a structural schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 4 of this disclosure. It is a structural schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 5 of this disclosure. It is a structural schematic diagram of the bearing monitoring apparatus which concerns on Embodiment 6 of this disclosure.

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 components described in the following embodiments are not intended to limit the scope of the present invention only to them, but are merely explanatory examples.

(Embodiment 1)
As shown in FIG. 1, a rotating machine 1 such as a steam turbine or a compressor includes a rotating shaft 2, a rotor 3 fixed to the rotating shaft 2, and a bearing 4 that supports the rotating shaft 2. As shown in FIG. 2, the bearing 4 has two bearing pads 11 and 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 2a of the rotating shaft 2. A nozzle 12 for supplying lubricating oil to each gap 5 formed between the inner peripheral surface 11a of the rotary shaft 2 and the outer peripheral surface 2a of the rotating shaft 2 is provided. A refueling pipe 13 for circulating lubricating oil is connected to each nozzle 12, and a refueling pump 14 is provided in the refueling pipe 13.

The rotary 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 detecting 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 rotating shaft 2. The pressure detecting member 30 includes three fixed pressure sensors 31, 32, 33. The fixed pressure sensors 31, 32, and 33 are provided on the inner peripheral surface 11a of each bearing pad 11 at intervals along the circumferential direction of the rotating 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 lubricating oil 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 measuring unit 21, respectively. The lubrication pump 14 is electrically connected to the lubricating oil supply amount adjusting unit 22. The starved angle measuring unit 21 is configured to measure the starved angle, which will be described later, based on the value detected by the pressure detecting member 30. The lubricating oil supply amount adjusting unit 22 adjusts the operating conditions of the lubrication pump 14 in order to adjust the supply amount of the lubricating oil supplied to each gap 5 based on the starved angle measured by the starved angle measuring unit 21. It is configured to issue a command.

Next, the operation of the bearing monitoring device 10 according to the first embodiment will be described.
As shown in FIG. 1, in the rotating machine 1, the rotor 3 rotates when the rotating shaft 2 supported by the bearing 4 rotates. As shown in FIG. 2, the lubricating oil flowing through the refueling pipe 13 is supplied from each nozzle 12 to each gap 5 by the refueling pump 14, 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 ends of the gap 5 in the circumferential direction of the rotating shaft 2, the end closer to the nozzle 12 is set as the proximal end 5a of the gap 5, and the proximal end in the circumferential direction of the rotating shaft 2 is set. The end of the gap 5 facing 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 which is a central angle centered on the axis L of the rotating shaft 2. When the lubricating oil 15 is filled in the gap 5 from the proximal end 5a to the distal end 5b in the circumferential direction of the rotating shaft 2, the pad tension angle becomes the maximum value θ ₀ .

On the other hand, during the 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 5a of the gap 5. The range of the starved region SR in the circumferential direction of the rotating shaft 2 is represented _{by a starved angle θ S} , which is a central angle centered on the axis L of the rotating shaft 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 that when the pad tension angle is θ _0. Therefore, when the starved region SR is formed, the dynamic characteristics of the bearing 4 change. Therefore, 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 value detected by the pressure detecting 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 5a to the distal end 5b of the gap 5, and two fixed pressure sensors 31, 32, 33 are provided. It is assumed 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, when the change with time of the detected value of each fixed pressure sensor is shown in FIG. 4, the detected values of the fixed pressure sensors 31 and 32 located in the starved region SR remain almost zero, whereas the lubricating oil 15 The fixed pressure sensor 33 located in the region filled with is detected the oil film pressure of the lubricating oil 15 larger than zero.

From the time course of the detected value by each fixed pressure sensor, as shown in FIG. 3, the starved region SR is the fixed pressure sensor 32 and the fixed pressure sensor 33 from the proximal end 5a in the circumferential direction of the rotating shaft 2. It can be seen that the range is up to the position between and. In this case, the starved angle measuring unit 21 (see FIG. 2) of the control unit 20 sets the range from the proximal end 5a to the fixed pressure sensor 32 as the starved angle, or sets the range from the proximal end 5a to the fixed pressure sensor 33, for example. The starved angle is defined as 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 defined as the starved angle, or the starved angle is determined by other methods. be able to. In any of these examples, there will be some deviation from the _{actual starved angle θ S.} This deviation can be reduced by increasing the number of fixed pressure sensors and reducing the distance between them.

By the way, the relationship between the starved region and the stability of the shaft system, particularly the relationship between the starved angle and the damping ratio indicating the easiness of damping the vibration of the rotating shaft has not been clarified 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 was clarified that the damping ratio tends to decrease as the starved angle increases. Then, as the starved angle increases, the risk of peaky vibration increases. Therefore, it is considered that the risk of peaky vibration occurring can be reduced by increasing the supply amount of the lubricating oil and lowering the starved angle.

Therefore, in the first embodiment, as shown in FIG. 2, the upper limit value of the starved angle is set in advance in the lubricating oil 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 elemental tests of the present inventors, the starved angle corresponding to the lower limit of the damping ratio in which peaky vibration can occur is obtained, and this is used as the upper limit of the starved angle. 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 the preset upper limit value of the starved angle. When the former is smaller than the latter, it is judged that the possibility of peaky vibration is low. On the other hand, when the former is the latter or more, 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 supply amount of the lubricating oil to be supplied to the gap 5.

When the lubricating oil supply amount adjusting unit 22 determines to increase the supply amount of the lubricating oil to the gap 5, the lubricating oil supply amount adjusting unit 22 sends a command to increase the supply amount to the refueling pump 14 to operate the refueling 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 due to the increase in the supply amount may be changed.} It may be acquired from the starved angle measuring unit 21 in real time, 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 peaky vibration can be reduced.

In this way, it is possible to determine whether or not the starved region is formed from the measured starved angle θ _{S, so that 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 detecting member 30 includes three fixed pressure sensors 31, 32, 33, but is not limited to three. As described above, increasing the number of fixed pressure sensors increases the measurement accuracy of the starved angle. Therefore, the pressure detection member 30 may have any number of four or more fixed pressure sensors, but the size of the bearing 4. Depending on the above, the pressure detection member 30 may be composed of two fixed pressure sensors.

(Embodiment 2)
Next, the bearing monitoring device according to the second embodiment will be described. The bearing monitoring device according to the second embodiment is a modification of the first embodiment in which the configuration of the pressure detecting member is changed. In the second embodiment, the same reference numerals as those of the constituent requirements of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 5, the bearing monitoring device 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. It includes a detection member 30. The rotational pressure sensor 35 is provided on the outer peripheral surface 2a of the rotating shaft 2 and rotates together with the rotating shaft 2. The detected value of the rotational pressure sensor 35 can be transmitted to the starved angle measuring unit 21 of the control unit 20. In order to enable transmission of the detected value of the rotational pressure sensor 35 to the starved angle measuring unit 21, for example, a telemeter may be installed to wirelessly transmit the detected value to the starved angle measuring unit 21, or the rotational pressure sensor 35 may be transmitted. The electric wire connected to the rotating shaft 2 is extended to the end of the rotating shaft 2 along the length direction thereof, and is connected to the electric wire connected to the starved angle measuring unit 21 via a slip ring provided at the end of the rotating shaft 2. It may be configured to be electrically connected. Other configurations are the same as those in 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.} Therefore, 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. Therefore, peaky. The generation of vibration can be suppressed.

In the second embodiment, since the pressure detecting member 30 is configured by one rotational pressure sensor 35 provided on the outer peripheral surface 2a of the rotating shaft 2, the operation of detecting the oil film pressure of the lubricating oil 15 in the gap 5 is carried out. As a result, the measurement operation of the _{starved angle θ S} is different from that of the first embodiment. Since the rotational pressure sensor 35 rotates together with the rotating shaft 2, it enters the gap 5 from the proximal end 5a, moves in the gap 5 in the circumferential direction of the rotating 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 of the rotating shaft 2 in the circumferential direction is represented by an angular position centered on the axis L of the rotating shaft 2, the graph of the value detected by the rotating 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, and the starved region SR having a starved angle θ S} is formed in the gap 5, the value detected by the rotational pressure sensor 35. The angle range from α _5a to α _S (= α _5a + θ _S ) is almost zero, _{increases after passing the angle position α S} , reaches the maximum value, and then turns to decrease, and then turns to the angle position. It becomes zero at α _5b. That is, the range from the angle position α _5a where the value detected by the rotational pressure sensor 35 is zero is the 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 rotary 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. Compared with, the starved angle θ _S can be measured more accurately. However, since the configuration for transmitting the value detected by the rotational pressure sensor 35 to the starved angle measuring unit 21 becomes complicated as described above, the configuration of the pressure detecting member 30 becomes complicated as compared with the first embodiment. In other words, the first embodiment has an effect that the configuration of the pressure detecting member 30 becomes simpler than that of 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 can be obtained, a more accurate starved angle θ _S can be measured _{by calculating the average of the starved angles θ S obtained from each graph.}

The pressure detection member 30 includes the fixed pressure sensors 31, 32, 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 may be included.

(Embodiment 3)
Next, the bearing monitoring device according to the third embodiment will be described. The bearing monitoring device 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 was changed as follows. Hereinafter, the third embodiment will be described with the configuration of the first embodiment modified as described above, but the third embodiment may be configured by modifying the configuration of the second embodiment as described above. In the third embodiment, the same reference numerals as those of the constituent requirements of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 7, the bearing monitoring device 10 according to the third embodiment includes a control unit 20 and a pressure detecting member 30. The control unit 20 includes a starved angle measuring unit 21, 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. A damping ratio estimation unit 24 electrically connected to each of the units 22 is included. Other configurations are the same as those in the first embodiment.

Also in the third embodiment, the operation in which the pressure detecting member 30 detects the oil film pressure of the lubricating oil in the gap 5 and the starved angle measuring unit 21 measures the starved angle based on the detected value is the same as that in the first embodiment. be. 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 determines the ease of damping the vibration of the rotating shaft 2 based on the calculated bearing constant. Is different from the first embodiment in that the damping ratio representing the above is estimated and 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. The operation different from the first embodiment will be described below.

The bearing constant calculation unit 23 sets the analysis conditions of the bearing analysis model such as Thermo-Hydrodynamic 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 mechanical model of the axial system which is a finite model by beam elements, and performs the axial system stability calculation on this mechanical model to obtain the damping ratio. presume. As the mechanical model, the mechanical model at the time of designing the rotating machine 1 can be used.

The upper limit value of the starved angle and the lower limit value of the damping ratio are set in advance in the lubricating oil supply amount adjusting unit 22. The lubricating oil 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 compares the damping ratio estimated by the damping ratio estimating unit 24 with the damping ratio. , Compare with the preset lower limit of the damping ratio. Lubricating oil supply amount when the starved angle measured by the starved angle measuring unit 21 is equal to or higher than the upper limit of the starved angle and the damping ratio estimated by the damping ratio estimation unit 24 is equal to or lower than the lower limit of the damping ratio. The 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. 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 immediately occur when a starved region occurs. That is, the sensitivity to the shaft system stability in the state where the lubricating oil is insufficient (starved state) differs depending on the characteristics of the rotating shaft 2 and the bearing 4. Therefore, if the supply amount of the lubricating oil is increased only according to the starved angle, the supply amount of the lubricating oil increases even though the possibility of peaky vibration is low, and the rotary machine 1 Performance may deteriorate. However, in the third embodiment, the damping ratio is estimated from the measured starved angle, and the risk of peaky vibration caused by the bearing is estimated from both the starved angle and the damping ratio, so that the risk of peaky vibration is more accurately estimated. Can be estimated.

(Embodiment 4)
Next, the bearing monitoring device according to the fourth embodiment will be described. The bearing monitoring device 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. It was changed to adjust. Hereinafter, the fourth embodiment will be described by modifying the configuration of the first embodiment as described above, but the fourth embodiment may be configured by modifying the configuration of the second embodiment as described above. In the fourth embodiment, the same reference numerals as those of the constituent requirements of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 8, the bearing monitoring device 10 according to the fourth embodiment includes a control unit 20, a pressure detecting member 30, and a vibration information detecting member 40 that detects vibration information related to vibration of the rotating shaft 2. There is. In the following description, the vibration information will be described as the displacement of the rotating shaft 2. Therefore, 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 velocity, 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 detecting member is a speed sensor, an acceleration sensor, or the like.

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

Also in the fourth embodiment, the operation in which the pressure detecting member 30 detects the oil film pressure of the lubricating oil in the gap 5 and the starved angle measuring unit 21 measures the starved angle based on the detected value is the same as that in the first embodiment. be. In the fourth embodiment, the damping ratio estimation unit 24 estimates the damping ratio indicating the ease of damping of the vibration of the rotating shaft 2 based on the displacement of the vibration of the rotating shaft 2 measured by the displacement sensor 40a, and the starved angle. It differs 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 damping ratio and the damping ratio. The operation different from the first embodiment will be described below.

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

The operation of the lubricating oil supply amount adjusting unit 22 adjusting the supply amount of the lubricating oil based on both the starved angle and the damping ratio is the same as the operation of the third embodiment. Therefore, even in the fourth embodiment, the risk of peaky vibration can be estimated more accurately by estimating the risk of peaky vibration caused by the bearing from both the starved angle and the damping ratio.

(Embodiment 5)
Next, the bearing monitoring device according to the fifth embodiment will be described. The bearing monitoring device according to the fifth embodiment estimates the damping ratio from the measured starved angle and also estimates the damping ratio from the actual vibration of the rotating shaft 2 for each of the first and second embodiments, and damps both of them. By comparing the ratios, a more accurate damping ratio is estimated, and the amount of lubricating oil supplied is adjusted based on both the starved angle and the damping ratio. Hereinafter, the fifth embodiment will be described with the configuration of the first embodiment modified as described above, but the fifth embodiment may be configured by modifying the configuration of the second embodiment as described above. In the fifth embodiment, the same reference numerals as those of the constituent requirements of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

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

The control unit 20 includes a starved angle measuring unit 21, a lubricating oil supply amount adjusting unit 22, a bearing constant calculation unit 23 electrically connected to the starved angle measuring unit 21, a displacement sensor 40a, 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 in the first embodiment.

Also in the fifth embodiment, the operation in which the pressure detecting member 30 detects the oil film pressure of the lubricating oil in the gap 5 and the starved angle measuring unit 21 measures the starved angle based on the detected value is the same as that in the first embodiment. be. In the fifth embodiment, the damping ratio estimation unit 24 is based on both the displacement of the vibration of the rotating shaft 2 measured by the displacement sensor 40a and the bearing constant calculated by the bearing constant calculation unit 23 based on the measured starved angle. However, the damping ratio indicating the ease of damping of the vibration of the rotating shaft 2 is estimated, and the lubricating oil supply amount adjusting unit 22 adjusts the lubricating oil supply amount based on both the starved angle and the damping ratio. It is different from the first embodiment. The operation different from 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 in the third embodiment, and the displacement is The operation of the damping ratio estimation unit 24 to estimate the damping ratio based on the displacement of the vibration of the rotating shaft 2 measured by the sensor 40a is the same as that of the fourth embodiment. In the fifth embodiment, the damping ratio estimation unit 24 can estimate the damping ratio more accurately by comparing and correcting the two damping ratios estimated in this way. As an example of this correction method, it is difficult to reflect the influence of unknown structural damping (ζ str) in the actual machine in the analysis value (ζ cal) of the damping ratio based on the dynamic model, so the measured damping ratio (ζ exp). It is conceivable to correct the analysis value as follows using.
ζ cal (after correction) = ζ cal + ζ str
ζ str = ζ exp0-ζ cal0
Here, the subscript 0 means a value under an arbitrary reference condition such as a condition in which the supply amount of lubricating oil is large.

The operation of the lubricating oil supply amount adjusting unit 22 adjusting the supply amount of the lubricating oil based on both the starved angle and the damping ratio is the same as the operation of the third and fourth embodiments. Therefore, even in the fifth embodiment, the risk of peaky vibration can be estimated more accurately by estimating the risk of peaky vibration caused by the bearing from both the starved angle and the damping ratio.

(Embodiment 6)
Next, the bearing monitoring device according to the sixth embodiment will be described. The bearing monitoring device according to the sixth embodiment estimates the damping ratio for each of the fourth and fifth embodiments based on the displacement of the vibration of the rotating shaft due to the exciting force applied to the rotating shaft by the exciter. It was changed as follows. Hereinafter, the sixth embodiment will be described by modifying the configuration of the fourth embodiment as described above, but the sixth embodiment may be configured by modifying the configuration of the fifth embodiment as described above. In the sixth embodiment, the same reference numerals as those of the constituent requirements of the fourth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 10, the bearing monitoring device 10 according to the sixth embodiment includes a control unit 20, a pressure detecting member 30, a vibration information detecting member 40 for detecting vibration information related to vibration of the rotating shaft 2, and a rotating shaft. It is provided with a vibrating machine 50 that applies a vibrating force to 2. The 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 in the fourth embodiment. In the sixth embodiment, similarly to the fourth embodiment, the vibration information detection member 40 is assumed to be the displacement sensor 40a, and the following description will be given. However, the present invention is not limited to the displacement sensor 40a, which is the same as the fourth embodiment.

Also in the sixth embodiment, the operation of the pressure detecting member 30 detecting the oil film pressure of the lubricating oil in the gap 5 and the starved angle measuring unit 21 measuring the starved angle based on the detected value is the same as that of the fourth embodiment. be. In the sixth embodiment, the exciter 50 vibrates the rotating shaft 2 by applying a vibrating force to the rotating shaft 2, and the damping ratio is based on the displacement of the vibration of the rotating shaft 2 measured by the displacement sensor 40a. The estimation unit 24 is different from the fourth embodiment in that the estimation unit 24 estimates the damping ratio indicating the ease of damping the vibration of the rotating shaft 2. The operation different from that of the fourth embodiment will be described below.

The exciter 50 vibrates the rotating shaft 2 by applying a vibrating force to the rotating shaft 2. The value of this exciting force is transmitted to the damping ratio estimation unit 24. In this state, the displacement sensor 40a detects the displacement of the vibration of the rotating shaft 2 and transmits the detection result to the damping ratio estimation unit 24. Similar to the fourth embodiment, the damping ratio estimation unit 24 calculates the frequency spectrum by frequency-analyzing the time history waveform of the value detected by the displacement sensor 40a, and obtains the sharpness of the peak at the natural frequency of the obtained frequency spectrum. Estimate the damping ratio by the half power method or curve fitting. The operation of the damping ratio estimation unit 24 for estimating the damping ratio is the same as that of the fourth embodiment, but in the sixth embodiment, the exciting force applied to the rotating shaft 2 is due to the exciting device 50, so that the exciting force In that the input value is clear, the attenuation ratio can be estimated more accurately than in the case of the fourth embodiment.

The operation of the lubricating oil supply amount adjusting unit 22 adjusting the supply amount of the lubricating oil based on both the starved angle and the damping ratio is the same as the operation of the fourth embodiment. Therefore, even in the sixth embodiment, the risk of peaky vibration can be estimated more accurately by estimating the risk of peaky vibration caused by the bearing from both the starved angle and the damping ratio.

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

Each of the bearings 4 of the first to sixth embodiments has 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 the present invention is not limited to this embodiment. The bearing 4 may have, for example, a configuration having five bearing pads arranged in a ring shape around the rotating shaft 2. The number of bearing pads is not limited to 2 or 5, and the techniques of embodiments 1 to 6 of the present disclosure can be applied to bearings having at least one bearing pad.

1 Rotating machine 2 Rotating shaft 2a (Rotating shaft) Outer surface 3 Rotor 4 Bearing 5 Gap 5a (Gap) Proximal end 5b (Gap) Distal end 10 Bearing monitoring device 11 Bearing pad 11a (Bearing pad) Peripheral surface 12 Nozzle 13 Refueling pipe 13
14 Refueling pump 15 Lubricating oil 20 Control unit 21 Starved angle measurement unit 22 Lubricating oil supply amount adjustment unit 23 Bearing constant calculation unit 24 Damping ratio estimation unit 30 Pressure detection member 31 Fixed pressure sensor 32 Fixed pressure sensor 33 Fixed pressure sensor 35 Rotational 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 that monitors bearings to support the rotating shaft.
The bearing is
At least one bearing pad provided along the circumferential direction of the rotating shaft, and
It is provided with at least one nozzle for supplying lubricating oil between the inner peripheral surface of the bearing pad facing the outer peripheral surface of the rotating shaft and the outer peripheral surface of the rotating shaft.
The bearing monitoring device is
A pressure detecting member configured to be able to detect the oil film pressure of the lubricating oil between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft along the circumferential direction of the rotating shaft.
Equipped with a control unit including a starved angle measurement unit
Based on the detection result of the pressure detecting member, the starved angle measuring unit is the peripheral surface of the region where the lubricating oil is insufficient between the inner peripheral surface of the bearing pad and the outer peripheral surface of the rotating shaft. A bearing monitoring device that measures a starved angle that represents the range with a central angle centered on the axis of the rotation axis, which is a range in the direction. The pressure detecting 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 at intervals along the circumferential direction of the rotating shaft. The bearing monitoring device according to claim 1. The bearing monitoring device according to claim 1 or 2, wherein the pressure detecting 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 lubricating oil supply amount adjusting unit.
Based on the starved angle, the lubricating oil supply amount adjusting unit adjusts the supply amount of 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 1 to 3. The control unit
A bearing constant calculation unit that calculates the bearing constant based on the starved angle, and a bearing constant calculation unit.
The bearing monitoring device according to any one of claims 1 to 3, further comprising a damping ratio estimation unit that estimates a damping ratio representing the 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 the vibration of the rotating shaft is further provided.
The control unit according to any one of claims 1 to 3, further comprising a damping ratio estimation unit that estimates a damping ratio representing the ease of damping of the vibration of the rotating shaft based on the vibration information. Bearing monitoring device. A vibration information detecting member for detecting vibration information related to the vibration of the rotating shaft is further provided.
The control unit
A bearing constant calculation unit that calculates the bearing constant based on the starved angle, and a bearing constant calculation unit.
3. The described bearing monitoring device. Further equipped with a vibration exciter that applies an excitation force to the rotating shaft,
The damping ratio estimation unit estimates the damping ratio based on the vibration information obtained from the vibration of the rotating shaft when the vibrating machine applies the exciting force to the rotating shaft. Item 6. The bearing monitoring device according to Item 6. The control unit further includes a lubricating oil 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, wherein the bearing monitoring device is adjusted. Rotation axis and
A bearing for supporting the rotating shaft, at least one bearing pad provided along the circumferential direction of the rotating shaft, an inner peripheral surface of the bearing pad facing the outer peripheral surface of the rotating shaft, and the said. A bearing comprising at least one nozzle for supplying lubricating oil to and from the outer peripheral surface of the rotating shaft.
A rotary machine including the bearing monitoring device according to any one of claims 1 to 9.

Images