JPS6034344B2 - Abnormal sound detection device for rotating machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables early detection of abnormal conditions that occur during rotation of rotating machines such as rotating electric machines and turbines, such as rubbing of bearings, cracking of rotor parts, and seizure of coils. The present invention relates to an abnormal sound detection device for detecting an abnormal sound signal generated at that time.

Conventionally, when diagnosing, for example, a generator 1 as a test object as shown in FIG. 1 using abnormal sounds, the following apparatus has been used. That is, an abnormal sound detection sensor 2 is attached to a bearing part 3 on the stator side, and its output is passed through an amplifier 4 and a signal processing circuit 5 and monitored by a monitor 6. In this case, the sensor 2 is often used to detect acoustic or ultrasonic signals.
Generally, acoustic emission (hereinafter referred to as A
A sensor for detection (abbreviated as E) passes through it, and the frequency band used ranges from the audible range to several M range.
Such devices are relatively suitable for diagnosing abnormalities that occur on the stator side, but in the case of rotating machines, the dangerous parts are often on the rotor side, which is rotating inside the machine. I don't like that it can't be detected. On the other hand, for measuring temperature, stress, vibration, etc., there is also a wireless transmission method in which sensors are attached directly to the rotor and the signals are transmitted as radio waves. As shown in FIG. 1, in this device, a mounting jig 8 is attached to a rotor shaft 7, a detection sensor 9 and a transmitter 10 are mounted thereon, and a transmission antenna 11 transmits data to the ground. This radio wave is received by a receiving antenna 12, processed by a receiver 13, and monitored by a monitor 14. It is believed that abnormal sound detection can be measured using the same method, but in the case of large rotating machines, the centrifugal force is extremely large, so measures must be taken to prevent centrifugal force when installing the device. Furthermore, there are problems such as the fact that the detection area may be blinded depending on how and where the device is installed, and that it is difficult to accurately determine the location where the defect occurs. The present invention was conceived with this in mind, and therefore aims to reduce the influence of centrifugal force and reduce the influence of centrifugal force. An object of the present invention is to provide an abnormal sound detection device that has a wide detection area without blinds and can accurately locate the location of a defect.

In other words, the present invention has an abnormal sound detection sensor formed by a stagnation ring shoe and a vibration element fixed to the inner surface of the ring shoe, and in which the outer periphery of the end ring shoe The acoustic coupling between the abnormal sound detection sensor J and the rotor shaft is improved by closely aligning them with the holes, and a plurality of abnormal sound detection sensors in parentheses are arranged in parallel in the rut direction. The detection sensors are formed to have different transmission frequencies to locate the defect.
Z The present invention will be described in detail below based on the illustrated embodiments. FIG. 2 shows one example. Although a plurality of abnormal sound detection sensors 15 are arranged in parallel in the axial direction, in order to first explain the surroundings of the abnormal sound detection sensor, the other sensors will be omitted from the description. The rotor shaft 7 is provided with an inner hole 30 at its axial center. An abnormal sound detection sensor 5 (hereinafter referred to as a sensor) and a transmitter 16 are installed in the inner hole, and the sound is transmitted into the air by a transmitting antenna 17 also placed above the rotor wheel. This transmitter 16 is composed of a preamplifier and a frequency modulation circuit. This radio wave is received by the receiving antenna 18, and the received radio wave enters the receiver 19. The receiver 19 includes a demodulator 20 and an amplifier 2
1 and a signal processing circuit 22. The above-mentioned detection sensor 15 has a ring shoe 23 having an outer diameter inscribed in the inner hole 30' of the center of the vehicle, as shown in FIG.
One or more vibrating elements, such as piezoelectric ceramic elements 24a, 24b, and 24c, are attached to the inside thereof.

The ring shoe 23 is preferably made of the same material as the rotor, which is good in terms of acoustic coupling, but other materials may also be used. Further, it is more effective to cut a part of the ring shoe 23, that is, to make it a stagnation ring, and fill the gap between the ends with an elastic body 25 such as rubber. That is, by doing this, when inserting the sensor 15 into the inner hole of the shaft center, the sensor 15 can be easily inserted, and the acoustic coupling is also extremely good since it is brought into close contact with the inner hole by a long D force. Also, with this sensor, unlike when mounted around the shaft, there is no blind area in the detection area,
Furthermore, since the element is divided into a plurality of pieces, it is possible to sufficiently prevent the element from being broken due to deformation of the ring shoe. The connection between these elements is as shown in Figure 4.
4a, 24b, and 24c may be connected in series through the connection 31, or may be connected in parallel (not shown).
FIG. 5 shows the state in which the sensor 15 is inserted three times into the inner hole of the shaft. When the rotor ball 17 rotates, the centrifugal force pushes the sensor 15 outward, causing the elastic body 25 to rut. It stretches and adheres to the inner hole surface.

In addition, it is preferable to arrange the elements at equal distances on the circumference, but as shown in the figure, when the angle with the element is 8, and the angle without the element is 82, at least 8,>82
If they are arranged so that the sound or AE signal arrives from any position on the circumference, the signal can be received. Now, based on FIG. 6, a case where a plurality of sensors are arranged will be explained. A plurality of sensors and transmitters 26a to 26d are arranged in parallel in the inner hole 30 of the rotor shaft 7 in the vertical direction.
By installing this, it becomes possible to locate the location where abnormal noise or AE occurs in the direction of the vehicle. The figure shows a case where four sets of sensors and transmitters 26a to 26d are installed, receivers 27a to 27d are prepared corresponding to each set, and the carrier frequencies of each set are different. At this time, if an abnormal sound is generated from the location shown in the figure, that is, from the end 28 of the rotor body, the sensors 26a and 26b will obtain signal waves 29a and 29b, respectively, so the time difference ΔT between the rises of the signals will be By measuring this using the AE position locating device 28, it is possible to identify the defective location when the rotor is one-dimensional. As described above, the present invention includes an abnormal sound detection sensor formed by an end ring shoe and a vibration element fixed to the inner surface of the ring shoe, and in which the outer periphery of the organic ring shoe A plurality of the abnormal sound detection sensors of the parentheses are arranged in parallel in the direction of the ball so as to closely fit into the inner hole provided in the inner hole, and the transmission frequencies of the respective abnormal sound detection sensors are different from each other. Therefore, it is possible to obtain an abnormal sound detection device that is less affected by centrifugal force, has a wide detection area without blinds, and can accurately locate the location of a defect.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the usage state of the conventional abnormal sound detection device, Fig. 2 is an explanatory diagram showing the usage state of the abnormal sound detection device of the present invention, and Fig. 3 is a perspective view showing the single detection sensor. figure,
Fig. 4 is a connection diagram of the detection sensor, Fig. 5 is a sectional view of the rotor chick showing the device state of the detection sensor, and Fig. 6 is a usage state of the abnormal sound detection device according to another embodiment of the present invention. It is an explanatory diagram. 7... Rotor shaft, 16... Transmitter, 19... Receiver, 15... Abnormal sound detection sensor, 23... Ended ring shoe, 24a-24c... Vibration element. Younger brother's figure 2nd figure 3rd figure 4th figure

Claims (1)

[Claims] 1. An abnormal sound detection sensor provided on the rotor shaft and a transmitter that amplifies and transmits the detection signal of the abnormal sound detection sensor, and receives the signal of the transmitter on the fixed side. In the sound detection device, the abnormal sound detection sensor is formed by an end ring shoe and a vibration element fixed to the inner surface of the ring shoe, and the outer periphery of the end ring shoe is an inner hole provided at the rotor axis. A rotating machine, characterized in that a plurality of abnormal sound detection sensors are arranged in parallel in the axial direction, and each of the abnormal sound detection sensors is formed to have a different transmission frequency. Abnormal sound detection device. 2. The abnormal sound detection device for a rotating machine according to claim 1, wherein the vibration element is divided into a plurality of parts in the circumferential direction.