JPH0464034A - Monitoring device of abnormality of bearing of hydraulic machine - Google Patents

Abstract

PURPOSE:To enable early discovery of abnormality by a method wherein a set value set beforehand for each detection element is compared with a set value determined beforehand as an absolute value, detection elements exceeding set values are combined and subjected to theoretical judgement and thereby the abnormality is detected. CONSTITUTION:When a hydraulic machine is operated, electric signals A-1 to A-3 detected by a shaft runout sensor, a temperature detecting sensor and an oil film thickness detecting sensor are inputted to arithmetic circuits B-l to B-3, converted from analog signals to digital ones and inputted to a memory H and a discriminating circuit C. The signal exceeding a set value in the circuit C is inputted to a combination pattern preparing circuit D. In the circuit D, each detection element is compared with the one in the previous normal operation and abnormality is transmitted to an abnormality display element E and an alarm device element F. When the abnormality occurs, the signals in the memory H are all erased after they are outputted to a recorder G.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a bearing abnormality monitoring device for monitoring abnormalities in a bearing device in a hydraulic machine.

(Prior Art) In recent years, the scale of power generation plants and general industrial plants has continued to increase in size, and along with this, hydraulic machines have also become larger and the number of installed machines has also increased.

Since such hydraulic machines are required to have high reliability, it is necessary to perform maintenance and inspections on them reliably to prevent accidents. Abnormalities in bearings, which are particularly likely to cause accidents in hydraulic machinery, have a large effect on other equipment, so it is necessary to ensure maintenance.

As mentioned above, although bearings are important elements in hydraulic machinery, conventional methods for monitoring bearings are
Methods such as measuring bearing temperature, measuring shaft system vibration, or chemically analyzing lubricating fluid have been adopted, but these monitoring methods do not significantly increase the risk of damage to bearings. This has the disadvantage that it cannot be detected until it has progressed, and the problem is that by the time an abnormality is detected, it has often already developed into a bearing accident. When such a bearing accident occurs, it takes a long time to recover, and during that time the hydraulic machine is stopped. For this reason, the operating rate of the equipment decreases, which hinders productivity improvement. Bearings in hydraulic machines, which are large-capacity machines in particular, suffer from very significant losses. Therefore, if the bearing of a hydraulic machine becomes abnormal or initial damage occurs, it is very important to detect the problem and take necessary measures before it develops into a major bearing accident.

Now, among bearing devices commonly used, bearings using oil as the lubricating fluid are most commonly used.

In this type of bearing, when the chamber-shaft hydraulic machine is operated, an oil film is formed on the bearing due to the viscous effect of the oil on the contact surface with the main shaft, thereby preventing direct contact between the main shaft and the bearing.

(Problem to be Solved by the Invention) However, when the sliding surface is damaged due to poor assembly of the shaft system, overload, contamination of foreign matter, cavitation, etc., it becomes difficult to form an oil film between the bearing and the main shaft. In other words, the oil film becomes very thin and eventually breaks, leading to a bearing accident. Such monitoring methods, such as a method of measuring the bearing temperature before the oil film breaks, have a problem in that the responsiveness to changes in the oil film is extremely insensitive.

On the other hand, recently, as a method for directly monitoring the thickness of the oil film on a bearing, a device has been proposed in which a sensor for detecting the oil film is installed on the bearing.

These monitoring methods can detect abnormalities at a much earlier stage than monitoring methods such as bearing temperature.

However, since all of the above-mentioned detection devices independently detect each abnormality parameter of the bearing, even if there is no abnormality in the bearing itself, a malfunction of the detector itself or a bearing accident will not occur in an extremely short period of time. In some cases, such as when a certain degree of bearing abnormality occurs, an unnecessary error may be detected.

Furthermore, since this method detects abnormalities for each individual item, there is a problem in that it lacks accuracy as a means of clearly determining bearing abnormalities.

Furthermore, even if an abnormality is detected in various detection items, it is only considered to be an abnormality in the entire bearing, so it is impossible to detect the specific cause of the bearing abnormality, making it difficult to take appropriate measures for the abnormality. It is.

In addition, the set values for each detection element are determined by taking into account the influence of temperature differences between summer and winter, so the set values are higher in winter. Therefore, there is a problem in that the bearing is often found to be damaged too late.

The purpose of the present invention is to solve the above-mentioned problems of the prior art, to minimize damage to bearings of hydraulic machines, and to promptly and reliably detect signs of bearing abnormality in order to prevent the spread of the accident into a serious accident. An object of the present invention is to provide an automatic bearing monitoring device that enables appropriate measures to be taken by determining the location of an abnormality in a bearing.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention supports the main shaft of a hydraulic machine, detects the temperature and oil film thickness of a bearing filled with lubricating fluid, and supports the main shaft of a hydraulic machine. sensor means for detecting runout; calculation means for calculating detection elements consisting of time from start of operation, temperature, oil film thickness, and shaft runout based on signals from the sensor means; It is equipped with a storage means for storing the detection element, a determination means for comparing the previously detected element with the absolute value of +α, and an abnormality detection means for making a logical judgment by combining each detection element exceeding a set value and detecting an abnormality. The present invention provides an automatic bearing monitoring device.

Furthermore, a second abnormality detection means detects an abnormality by comparing the absolute values of the bearing temperature, oil film thickness, and shaft runout with predetermined set values; The present invention provides an automatic bearing monitoring device that includes an alarm means that outputs an alarm signal and a display signal indicating an abnormal location based on a combination of the outputs of the second abnormality detection means.

(Function) The function of the present invention is that whenever a hydraulic machine is newly installed, repaired, overhauled, etc., a load test is always carried out to confirm that there are no abnormalities. Each detection element of the load test is stored in a storage device from startup until each detection element becomes stable.

In the discrimination circuit, a set value of +α and an absolute value considered to be abnormal are set in advance for each of the stored detection elements.

When the value of each detection element during operation of the hydraulic machine exceeds each set value, an alarm signal and a display signal indicating the abnormality location are outputted based on the combination of the abnormality detection outputs.

Further, if each detection element is found to be normal, each detection element stored last time is deleted and each detection element of this time is stored and used for comparison during the next operation. By repeating this process and constantly comparing new operating records, bearings can be automatically monitored without calculations based on temperature differences between summer and winter, which can overlook even small changes.

(Example) An example of the present invention will be described below with reference to one drawing.

FIG. 1 is a longitudinal sectional view showing an example of a bearing to which an automatic bearing monitoring device according to the present invention is applied. As shown in the figure, the bearing part consists of a main shaft 1 and a segment bearing 2 attached to the main shaft 1.
and a pivot 4 and a bearing support part 3 that support this segment bearing 2. Bearing oil cylinder6. Bearing cover 7, bearing oil tank 9.
It consists of a lubricating oil 8 filled in a bearing oil tank 9 and a cooling pipe 5 that cools the lubricating oil 8.

A shaft runout sensor 10 is installed above the bearing cover 7 to detect shaft runout of the main shaft. Axial vibration sensor 10 is 9
There are two installed in the 0″′ direction.

FIG. 2 is an explanatory diagram showing how each detection sensor is attached to the segment bearing 2. As shown in FIG. The temperature detection sensor 11 is used to detect the bearing temperature, and the oil film thickness detection sensor 12 is used to detect the oil film thickness of the bearing.

FIG. 3 is a block diagram of an automatic bearing monitoring device according to an embodiment of the present invention. The electric signals A-1, A-2°A-3 are sent to the shaft runout sensor 10, temperature detection sensor 11. These are each output signal of the oil film detection sensor 12.

Arithmetic circuits B-1, B-2, and B-3 correspond to each detection sensor 10.
．． 11. Convert the detection elements corresponding to the electrical signals A-1, A-2, and A-3 from 11.12 from analog signals to digital signals.

The digital signals converted by these arithmetic circuits B-1, B-2, and B-3 further enter a discrimination circuit C. Here, each detection element that should be determined to be abnormal is set in advance, and the set value +α that should be determined to be abnormal is set in advance to the storage device H in which each detection element during normal operation is stored together with the operating time. Set it.

The discrimination circuit C compares and discriminates the detected value and the set value of the absolute value with the stored set value of each test element 1α, and similarly, if the detected value is normal, the previous record in the storage device H is erased. Store the detected value.

If the detected value exceeds the set value, the detected value is sent to the next combination pattern creation circuit.

FIGS. 4 and 5 are explanatory diagrams showing examples of patterns of combination pattern creation circuits separated for each abnormality content of the bearing.

In the figure, input items x1 to x6 are for each detection sensor 10.
, 11. These are the item conditions determined to be abnormal by the discriminating circuit C based on the signals from the detection elements of 12.

In each of the patterns Di and D2 in FIGS. 4 and 5, the logic circuit is configured such that when the AND condition or OR condition from the input items X1 to x3 is satisfied, a signal is transmitted to the output items Yl and Y2. There is.

When signals are sent to the output items Yl and Y2 in the combination pattern creation circuits Di and D2, these signals are transmitted to the abnormality display section E and alarm device section F, and the content of the abnormality of the bearing is displayed.

In the configuration as described above, the operation will be explained.

When the hydraulic machine is operated, the electric signals A-1, A-2, and A-3 detected by each sensor 10, 11, and 12 are input to the calculation circuits B-1, B-2, and B-3, and are converted into analog signals. is converted into a digital signal and input to the memory bag NM and the discrimination circuit C.

The set value of the discrimination condition in the discrimination circuit C can be changed depending on the operation mode, for example, power generation, pumping, phase adjustment, partial load, etc. in a hydraulic machine. Signals exceeding the set value in the discrimination circuit are input to the combination pattern creation circuit.

FIG. 4 shows a combination pattern creation circuit D1 for detecting initial bearing abnormalities. Input item XI regarding the abnormality detection element input from the discrimination circuit C.

X2. X3 is as follows.

xl・Bearing temperature Abnormality compared to the previous operation x2・Bearing oil film Abnormality compared to the previous operation X3... Shaft runout Abnormality compared to the previous operation Bearing initial abnormality is Xi, X2. Even if each of X3 is output independently, it is transmitted to the abnormality display section E and alarm device section F.

FIG. 5 shows a combination pattern creation circuit D2 for detecting bearing absolute value abnormalities.

Input items Xi, X2. related to abnormality detection elements input from the discrimination circuit C. X3 is as follows.

×1 - Bearing temperature absolute value abnormality xl... Bearing oil film absolute value abnormality x3 - Shaft runout absolute value abnormality Bearing absolute value abnormality is Xi, X2. Even if each of X3 is output independently, it is transmitted to the abnormality display section E and alarm device section F.

Due to the above-described configuration and operation, when any one of the detection elements exceeds a set value, an abnormality is displayed for each detection element.

In addition, each detection element is input to the storage device M regardless of whether it is normal or abnormal, and if the operation ends normally, the record from the previous operation is erased and the current record is stored.

Furthermore, if an abnormality occurs, the data will not remain in the storage device but will be output to the recording device G and then erased.

〔Effect of the invention〕

As described above, according to the present invention, each detection element can be compared with the previous normal operation, and even small changes can be monitored without being overlooked, allowing early detection of abnormalities.

Furthermore, by storing one normal operation record, the function of the bearing abnormality monitoring device will be satisfied from the next time, and abnormality monitoring can be performed without collecting various data.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a bearing to which a bearing abnormality monitoring device according to the present invention is applied, FIG. 2 is an explanatory view showing how various detection sensors are attached to a segment bearing, and FIG. The functional block diagram of the bearing abnormality monitoring device according to the embodiment, and FIGS. 4 and 5 are explanatory diagrams showing examples of patterns of the combination pattern creation circuit. 1. Main shaft 2. Segment bearing 3...
Bearing support part 4 Pivot 5-/Cooling pipe
6...Bearing oil cylinder 7/Bearing cover 8 Lubricating oil 9...Bearing oil tank 10...Shaft runout sensor 1
1...Temperature detection sensor 12...Oil film thickness detection sensor Agent Patent attorney Noriyuki Chika Figure 1 Figure 2 Figure Figure

Claims (1)

[Claims] In a bearing device installed on the main shaft of a hydraulic machine, a sensor means detects one or more of the temperature and oil film thickness of the bearing filled with lubricating fluid, and the shaft runout of the main shaft, and the sensor means detects one or more of the following: calculation means for converting detection elements such as temperature, oil film thickness, and shaft runout from analog signals to digital signals; storage means for storing the calculated results; A hydraulic machine characterized by being equipped with a discrimination means for comparing with a predetermined set value as a number and an absolute value, and an abnormality detection means for making a theoretical judgment by combining each detection element exceeding the set value and detecting an abnormality. Bearing abnormality monitoring device.