JPH01261511A - Automatic surveillange device and surveillance method for thrust bearing unit - Google Patents

Abstract

PURPOSE:To early detect a premonitory phenomenon of abnormality by detecting a bearing temperature, a lubricating fluid temperature inside a vessel, the pressure and the thickness of a lubricating fluid film, then operating an average value, an absolute value, the rate of change by time, and an amplitude, and comparing the above operation values with their set values, for abnormality judgement of each type. CONSTITUTION:A temperature sensor 21, an oil pressure sensor 22, an oil thickness sensor 23 are attached to this stationary plate 15, the signals output from the above sensors are input to an automatic surveillance circuit A with a detection signal of a temperature sensor inside an oil vessel 24. This automatic surveillance circuit A operates an average value, an absolute value, the rate of change by time, and an amplitude, and outputs each type of abnormality signals, logic judgement, alarm signals when the above operation values exceed the set values. A premonitory phenomenon of abnormality is thus early detected to reduce damages and to prevent from causing serious accidents. A fan-shaped stationary plate 15 is supported to a rotary shaft 11 via thrust collar 2 and radially supported to a spring stand 18 via a coil spring 16 toward the bottom side of a guide bearing 13.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a thrust bearing device for supporting a rotating shaft of an optical axis rotating machine. The present invention relates to an automatic monitoring device for a thrust bearing device and a method for monitoring a thrust bearing device, which are capable of detecting abnormalities in a stationary plate at an early stage by grasping the formation state of the stationary plate.

(Prior Art) In recent years, the scale of plants in the -i industry has continued to increase in size, and along with this, rotating machines have also become larger and their installations have also increased. Therefore, since high reliability is required for such rotating machines, it is necessary to perform maintenance and inspections reliably to prevent accidents.

In particular, abnormalities in thrust bearings that tend to cause accidents in rotating machines have a large effect on other parts, so maintenance must be performed more reliably.

Conventionally used high load thrust bearings include v
1 Thrust bearings that use lubricating oil as the lubricating fluid are most commonly used. In this type of bearing, during the operation of the optical axis rotating machine, an oil pattern is formed between the stationary plates due to the viscous effect of the oil on the sliding surface of the rotating shaft, and the direct contact between the rotating shaft and the stationary plate is caused. Contact is prevented.

Although the thrust bearing in the above rotating machine is an important element, the method for monitoring it is extremely insufficient. In other words, conventional methods for monitoring thrust bearings include measuring the temperature of the stationary plate, measuring vibrations in the shaft system, and chemically analyzing the lubricating oil. This monitoring method has the disadvantage that damage to the thrust bearing cannot be detected until it has progressed considerably, and by the time an abnormality is detected, it has often already developed into a bearing accident.

When this bearing accident occurs, it takes a long time to recover, and during that time the rotating machine is stopped, which reduces its operating rate and becomes an impediment to improving productivity. In particular, damage to the thrust bearing in a large-capacity water turbine optoelectric machine results in a huge loss to the rotating machine. Therefore, when such a thrust bearing is in a normal state or initial damage occurs, it is very important to detect it and take necessary measures before it develops into a major bearing accident.

(Problem to be Solved by the Invention) However, when the sliding surface is damaged due to poor assembly of the shaft system, overload, foreign matter, cavitation, etc., it becomes difficult to form an oil film between the stationary plate and the rotating shaft. In other words, the oil film becomes so thin that it may eventually break and develop into a bearing wheel. Before the oil film ruptures, the above-mentioned method of monitoring the bearing, such as by measuring the temperature of the stationary plate of the bearing, has very poor responsiveness to changes in the oil film, making it difficult to detect signs of bearing abnormality at an early stage. cannot be detected.

On the other hand, recently, a monitoring device for directly monitoring the thrust bearing oil film thickness and oil film pressure has been proposed, in which a sensor is installed on a stationary plate to detect them. These monitoring devices can detect abnormalities at a much earlier stage than monitoring methods such as bearing temperature measurement.

However, since all of the above-mentioned monitoring devices detect individual items such as oil film thickness and oil film pressure, for example, even if there is no abnormality in the bearing body, the sensor itself may malfunction, or if a bearing abnormality actually occurs, it will take a very short period of time. If the bearing returns to normal, it may be detected as a bearing abnormality at the time the abnormality occurs, and it is considered to lack accuracy as a means of determining a clear thrust bearing abnormality. Furthermore, even if an abnormality is detected using the individual detection items such as oil film thickness or oil film pressure, it can only be determined as an abnormality in the bearing body, so it is difficult to determine whether an abnormality has occurred in the thrust bearing body or the cooling system. Yes, it takes a lot of time to recover from a bearing accident.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to be able to detect signs of abnormalities in the thrust bearing device at an early stage, and to detect abnormalities in the thrust bearing body or the cooling system. It is possible to carry out up to Ii, thereby reducing the loss of the thrust bearing device (5) as much as possible,
Our objective is to provide an automatic monitoring device for thrust bearing devices and a method for monitoring thrust bearing devices that can prevent the spread of accidents into serious accidents.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a bearing temperature sensor arranged in a bearing device to detect the bearing temperature, and a bearing lubricating fluid film arranged in the bearing device. A bearing lubricating fluid film pressure sensor that detects pressure, a bearing lubricating fluid film IV sensor placed inside the bearing device that detects the thickness of the bearing lubricating fluid, and a bearing lubricating fluid film sensor placed inside the bearing lubricating fluid tank that detects the temperature of the lubricating fluid. an in-tank lubricating fluid temperature sensor, a calculation means for calculating detection elements such as an average value, an absolute value, a time rate of change, and an amplitude from detection signals from these sensors, and detection elements from this calculation means and predetermined settings. a comparison means that compares the value with the set value and outputs various abnormal signals when the detection element exceeds the set value; an alarm means that makes a logical judgment based on a combination of the various abnormal signals from the comparison means; This is an automatic monitoring device for a thrust bearing device, which is equipped with an alarm device that inputs various abnormal signals from the means and outputs an alarm, and a display device that displays the alarm signal output from the alarm failure. Further, the present invention detects the bearing temperature of the bearing device, the bearing lubricating fluid film pressure, the bearing lubricating fluid film thickness, and the lubricating fluid temperature in the tank by a detection means, and based on the detected values, calculates the average value, absolute value, and time. The detection elements of rate of change and amplitude are calculated, and when the calculation result exceeds a predetermined set value, it is determined whether the various detection elements are in an abnormal state, and the combination of these judgment results determines whether the logical conditions are satisfied. This is a monitoring method for monitoring abnormalities in thrust bearing devices.

(Function) As described above, the bearing temperature, lubricating fluid film pressure, lubricating fluid film thickness, and tank lubricating fluid temperature are detected, and the average value, absolute value, time rate of change, and amplitude calculated based on the detected values are The detection element is compared with the set value, and when the detection element exceeds the set value, various abnormalities are determined, and logical judgments are made based on the combination of these, and based on the results of this judgment, the thrust bearing device is adjusted. Since abnormalities are monitored, signs of failure of the thrust bearing device can be detected at an early stage, and the abnormality of the thrust bearing body or the cooling system can be isolated.

(Examples) Hereinafter, examples of the present invention shown in the drawings will be described. First, with reference to FIG. 1, we will explain an example of a thrust bearing device for a large direct-axis rotary machine in which lubricating oil is used as the lubricating fluid. A cylindrical thrust collar 12 is attached to the rotating shaft 11 by a cylinder key (not shown). The side surface of the thrust collar 12 is guided by a guide bearing 13, and a rotary plate 14 is fixed to the bottom surface thereof with bolts (not shown).

Further, eight fan-shaped stationary plates 15 are arranged radially relative to the rotating plate 14 in the direction of the rotating shaft 11. These stationary plates 15 are supported by a spring stand 18 provided at the bottom of the bearing oil tank 17 via eight coil springs 16 as shown. Then, the rotating plate 14 and the stationary plate 1
5. The coil spring 16 and the spring stand 18 are housed in a bearing oil tank 17 filled with lubricating oil 19. The lubricating oil 19 is cooled by an oil cooling pipe 20 and enters between the rotary plate 14 and the stationary plate 15 to perform a lubricating action.

As shown in FIG.
is attached. These sensors 21.22.23 are
Although it is normally installed on one stationary plate 15, in some cases it may be arranged in multiple stationary plates 15 around the entire circumference, and an oil tank oil temperature sensor 24 is provided in the bearing oil tank 17. ing.

Furthermore, the automatic monitoring circuit (first
Figure A) is provided. In FIG. 3, the temperature detection signal a1 detected by the temperature sensor 21 is input to the arithmetic circuit B-1. This operation mouth i? 8Lsl is temperature detection signal a1
From this, a temperature absolute value signal x1 and a temperature time change signal X2 are calculated and output.

The oil film pressure detection signal a2 detected by the oil film pressure sensor 22 is input to the calculation port FIPtB-2.

This operation mouth i? 8B-2 calculates and outputs an oil film pressure amplitude value x4 from the oil film pressure detection signal a2.

The oil film thickness detection signal a3 detected by the oil film thickness sensor 23 is input to the calculation circuit B-3.

The calculation circuit B-3 calculates and outputs an oil film thickness average value signal x6 and an oil film rg, time change rate signal x8 from the oil film thickness detection signal a3.

The oil tank oil temperature detection signal a4 detected by the oil tank oil temperature sensor 24 is input to the arithmetic circuit B-4. This calculation circuit B-4 inputs the oil temperature detection No. 18 a4 in the oil tank,
An absolute value signal x12 of the oil temperature in the oil tank is calculated and output.

Signals x1 and X2 output from the calculation port flB-1 are input to the comparator C-1, comparator C-100 and C-2, respectively, and the signal X4 output from the calculation circuit 11-2 is input to the comparator C-1 and the comparator C-100 and C-2, respectively. C-11, and further arithmetic circuit R
, -3, the signal x6. x8 is comparator C-6,
A signal x12 which is input to C-8 and further output from the arithmetic circuit [3-4] is input to comparator C-12. Then, when the signal xl input to the comparator C-1 is equal to or higher than the set value, the temperature absolute value abnormal signal X100 is output. The ratio? '+2 Signal x input to C-100
1 exceeds the set value, temperature absolute value abnormal signal x11
Outputs 0.

Also, if the signal X2 input to the comparator C-2 is greater than the set value, the zero-order ratio I! outputs the temperature time change rate abnormality signal x200! When the signal X2 input to the comparator C-200, which is set to a higher set value than the comparator C-2, exceeds the set value, it outputs a temperature time rate of change abnormal signal x210. When the signal x4 input to the comparator C-4 is greater than or equal to this set value, an oil film pressure amplitude value abnormality signal x40 is output.

If the input signal x6 input to comparator C-6 is greater than this set value, oil slick J! Output the 7th average value different times old number x60. When the signal X8 input to the comparator C-8 is greater than or equal to this set value, the oil film thickness time change rate) °4 ordinary double x8
Outputs 0.

When the signal x12 input to the comparator C-12 is greater than or equal to this set value, an oil tank oil temperature absolute value signal x120 is output, and this abnormal signal x120 is sent to the alarm T, the recording device G,
These signals are distributed and input to the thrust bearing cooling water system abnormality alarm port ill D-2.

Abnormal signals xlOO, xllO output from comparators C-1, C-100, C-2°C-200, C-4, C-6, C-8, respectively.

x200. x210. x40. x60. x80 is distributed and input to the thrust bearing body abnormality alarm circuit D-1 and the recording device G, respectively. In addition, abnormal signal x10
0 and x200 may not need to be input to the recording device G as shown in Fig. 3 depending on the case.Then, the main body abnormality alarm signal Y1, which is the output signal of the alarm circuit D-1, is input to the display E. The cooling water system abnormality alarm signal Y2, which is input to the IT and is configured to operate accordingly, and is the output signal of the alarm circuit D-2, is displayed on the display E.
It is configured to be input to the alarm I and the alarm T, respectively, and to be operated accordingly.

The alarm circuit D-1 is as shown in FIG.
c-1, C-100, C-2゜C-200, C-4, C
-6, C-8 respective abnormal signals xlOO, xllO
,,x200°x210. x40. x60. Input x80 and x210, of which the abnormal signal xllO.

x210 is input as is to the OR circuit 40c, and the abnormal signals xlOO and x60 are ORed via the AND circuit 41a.
The abnormal signal x200. x8
0 is input to the OR circuit 40c via the AND circuit 1\84Jb, and the abnormal signal x200. x40 is AND circuit 41
OR times I through c? 840c, and when the logical condition is satisfied, a main body abnormality alarm signal Y1 is generated. Further, the v-report circuit D-2 includes a comparator C-12.
The system is configured to issue a cooling water system abnormality alarm signal Y2 when an abnormality signal X120 is output from the system.

Next, a description of the thrust bearing device according to the present invention configured as described above will be explained. The operation of the IIJ monitoring device will be explained. When the water turbine generator starts operating in FIG. 1, the thrust collar 12 and the rotating plate 14, which are provided on the rotating shaft 11, rotate together. As a result, the rotating plate 14
An oil film is formed on the sliding surface of the Babbitt metal of the stationary plate 15, which is provided relative to the stationary plate 15. The bearing temperature, oil film pressure, oil film thickness, and oil tank oil temperature are measured by sensors 21 to 2, respectively.
4, and this detected analog detection signal is
Digital signals x1, x2, . x4. x6. x8. x1
2 is a comparator C-1°C-100, C-2, C-200,
C-4° is input to C-6, C-8, and C-12, where it is compared with a preset value.

This comparator C-1, C-100, C-2゜C-200,
Ratio in C-4, C-6, C-8, C-12! l12
The set values of the parameters can be changed depending on the operating mode (power generation, pumping, and phase adjustment in a hydroelectric power plant) load and cooling water temperature.

In any case, there are four items to detect an abnormality in a thrust bearing: temperature, oil film pressure, oil film thickness, and oil tank oil temperature, and the detection item for the temperature of the bearing body is an absolute value and a rate of change over time. For the detection item of the oil film pressure on the bearing body, the amplitude value is used as the detection element, and for the detection item of the oil film thickness on the bearing body, the average value and time rate of change are used as the detection element, and the cooling water system The temperature detection item in the oil tank is an absolute value, and each detection element calculated by each calculation circuit B-1 to B-4 is connected to each comparator C-1, C-100, and C-2°. C-200, C-4
, C-6, C-8, and C-12, the detection elements are compared with preset values for each detection element.

Abnormal signals xlOO, xllO, which are output when the set values are exceeded in comparators C-1, C-100, C-2°C-200, C-4, C-6, C-8 and C-12, respectively. x200°X210. x40. x
60. x80 and X120 are input to alarm circuits D-1 and D-2, respectively.

Next, the operation of the alarm circuit D-1 will be explained. comparison′
Various abnormal signals output from $1c-4, C-6, C-8, and C-12 are as follows.

xlOO, xllO...Temperature absolute value abnormal f word X200. X210...Temperature time change rate abnormal signal x40...Oil film pressure amplitude value abnormal signal x60...Oil film thickness average value abnormal signal x80...Oil film thickness time change rate abnormal signal Alarm circuit D in Fig. 4 The conditions for the main body abnormality alarm signal Y1 outputted from -1 to hold true are when the AND condition of the abnormal signals x100 and x60, which are the inputs, is satisfied in the AND circuit 41a, and the AND time 1? The abnormal signal x200.f141b is this input. When the AND condition of x80 is satisfied, the AND circuit 41c further outputs the abnormal signal x200. This is either a case where the AND clause 11 of x40 is established, or a case where the abnormal signal X110 or X210 is input alone. If any of the detection elements of the respective alarm circuits D-1 and D-2 in Fig. 3 exceeds the set value, the respective alarm signals Yl and Y2 are sent to the indicators E and H and the alarm T. The signals are input and displayed on the displays E and H for each detection item of each of the alarm circuits D-1 and D-2, and also emitted from the alarm T.

At the same time, the detection signals a1~ of each sensor 21~24
a4, detection signals xi of arithmetic circuits B-1 to B-4, x2.
x4. x6. x8. x12 and comparator C-100,C
-200, C-4° C-6, C-8, C-12 abnormal signal xllO.

X210. x40. x60. Normal x80° x120,
Regardless of the abnormality, it is recorded in the recording device G in synchronization with each signal, so if one of the detection elements displays an abnormality, it is necessary to check the history of other normal detection elements using the recording layer pG. This makes it possible to early detect signs of bearing abnormality in advance.

Therefore, an abnormality in the stationary plate 15 of the thrust bearing can be detected at an early stage before the oil film is damaged, and the cause of the abnormality and the location of the abnormality can be easily determined. It becomes possible to prevent accidents that have occurred or are likely to occur.

In the above embodiment, arithmetic circuits B-1 to B-4 that process detection signals a1 to a4 from each sensor 21 to 24, comparators C-1, C-2, C-4, C-6, C- 8, C-12
, alarm circuits D-1 and D-2 can be realized by computer software to achieve the same effect.

In addition, even if the recording device G described above records not all the time but at a certain period for a certain period of time in order to save on the recording medium, as long as the recording layer Jtll and time are set appropriately, there is no problem in practical use. There isn't.

[Effect of the invention 1] According to the present invention described above, the bearing temperature, lubricating fluid film pressure, lubricating fluid film thickness, and tank lubricating fluid temperature are detected, and the average value and absolute value determined based on these detected values are The detection elements of value, time rate of change, and amplitude are compared with the set value, and when the detected element exceeds the set value, various abnormalities are determined. Since abnormalities in the thrust bearing device are monitored based on this judgment result, signs of abnormalities in the thrust bearing device can be detected early, and abnormalities in the thrust bearing body or cooling system can be detected.
To provide an automatic monitoring device for a thrust bearing device and a method for monitoring the thrust bearing device, which can perform up to i, thereby minimizing damage to the thrust bearing device, and preventing escalation to a serious accident. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of an automatic monitoring device for a thrust bearing device according to the present invention, FIG. 2 is a plan view of a stationary plate showing the arrangement of various sensors in FIG. 1, and FIG. FIG. 4 is a block diagram showing a schematic configuration of the automatic monitoring circuit shown in FIG. 1, and FIG. 4 is a logic circuit diagram showing the thrust bearing main body abnormality alarm circuit shown in FIG. 11...Rotation axis, 12...Slus 1-Color, 13
... Kite bearing, 14 ... Rotating plate, 15 ... Stationary plate, 16 ... Coil spring, 17 ... Bearing oil tank, 18 ... Spring stand, one ... Lubricating oil, 20・
・・Oil cooled pipe, 21 ・・Thrust bearing temperature sensor, 22
... Thrust bearing oil film pressure sensor, 23... Thrust bearing oil ill sensor, 24... Oil tank internal oil temperature sensor, B-1 to B-4... Arithmetic circuit, C-1, C-1
00, C-2, C-200, C-4, C-6, C-8,
0-12... Comparator, D-1... Thrust bearing body abnormality alarm circuit, D-2... Thrust bearing cooling water system abnormality alarm circuit, E-H... Abnormality indicator, T...・Alarm, G...Recording device. Qlllll(1゛clean+E (within 'QI:', 'j'J
! Z L〕First day

Claims (2)

[Claims] (1) The thrust generated on the rotating shaft of a vertical rotating machine, etc. is supported by a plurality of stationary plates located in a bearing lubricating fluid tank and facing a rotating plate that rotates together with the rotating shaft with a lubricating fluid film interposed therebetween. In a thrust bearing device, a bearing temperature sensor arranged within the bearing device detects the bearing temperature, a bearing lubricating fluid film pressure sensor arranged inside the bearing device detecting the bearing lubricating fluid film pressure, and a bearing lubricating fluid film pressure sensor arranged inside the bearing device detecting the bearing lubricating fluid film pressure. A bearing lubricating fluid film thickness sensor that detects the thickness of the bearing lubricating fluid film arranged in the bearing lubricating fluid tank, an in-tank lubricating fluid temperature sensor that detects the temperature of the lubricating fluid arranged in the bearing lubricating fluid tank, and detection signals from these sensors. a calculation means for calculating the average value, absolute value, time rate of change, and amplitude detection elements from the calculation means, and a comparison between the detection elements from this calculation means and a predetermined set value, and if the detection element exceeds the set value, a comparison means that outputs various abnormal signals when a failure occurs, an alarm means that makes a logical judgment based on a combination of the various abnormal signals from the comparison means, and an alarm that outputs an alarm by inputting the various abnormal signals from the comparison means. 1. An automatic monitoring device for a thrust bearing device, comprising: an alarm device that displays an alarm signal output from the alarm means; and a display device that displays an alarm signal output from the alarm means. (2) The thrust generated on the rotating shaft of a vertical rotating machine, etc. is supported by a plurality of stationary plates located in a bearing lubricating fluid tank and facing a rotating plate that rotates together with the rotating shaft with a lubricating fluid film interposed therebetween. In a thrust bearing device, the bearing temperature, bearing lubricating fluid film pressure, bearing lubricating fluid film thickness, and tank lubricating fluid temperature of this bearing device are detected by a detection means, and based on these detected values, the average value, absolute value, and time are determined. The detection elements of rate of change and amplitude are calculated, and when the calculation result exceeds a predetermined set value, it is determined whether the various detection elements are in an abnormal state, and the combination of these judgment results determines whether the logical conditions are satisfied. A monitoring method for monitoring abnormalities in the above-mentioned thrust bearing device.