JPH09119861A - Vibration monitoring apparatus for motive-force transmission shaft system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus in which a torsional vibration and a longitudinal vibration can be detected simultaneously by the same technique, whose frequent calibration is not required, by which a remote monitoring operation and an elapse recording operation can be performed for many hours and which outputs a warning when the generation of an abnormal vibration is detected. SOLUTION: In an apparatus, accelerometers 4 in a rotation direction and an axial direction are attached to the shaft end part of a follower-side motive- force transmission shaft, detected acceleration signals are conveyed by an exclusive cable via a slip ring, they are input to an amplifier 5 so as to be amplified, amplified signals are decomposed into signals in a required frequency component by a band-pass filter 6, they are converted into a direct current by an AC-DC converter 7, and the signals are input to a monitor recorder 8 with an alarm device. A torsional vibration and a longitudinal vibration are monitored continuously for many hours by the recorder, their records are kept, and a warning is output when the generation of an abnormal vibration is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for monitoring torsional vibration and longitudinal vibration of a power transmission shaft system driven by an internal combustion engine.

[0002]

2. Description of the Related Art In order to monitor the vibration of a power transmission shaft system driven by an internal combustion engine, torsional vibration detects the twist angle generated on the shaft by a strain gauge, and longitudinal vibration displaces the axial displacement of the shaft end. A vibration monitoring device that detects by a meter is used.

[0003]

The following problems have been pointed out with respect to the above-described vibration monitoring device that has been conventionally used. (1) Since vibration detection methods differ between the detection of torsional vibration using a strain gauge and the detection of longitudinal vibration using a displacement gauge, the vibration monitoring device becomes complicated. (2) Strain gauges need to be frequently calibrated for temperature drift, etc., and periodic gauge replacement is necessary to ensure the reliability of the strain gauges. Therefore, the handling of the vibration monitoring device becomes complicated, and continuous monitoring for a long time is difficult.

(3) In a telemeter type vibration monitoring device that transmits the output of the strain gauge from the transmitter to the receiver by a carrier wave such as a sine vibration wave, in addition to the power source, it is used for modulation, transmission, reception and demodulation of the carrier wave. A device is required, and the structure and handling of the vibration monitoring device that can be used even during long-term continuous operation are complicated.

The object of the present invention is to solve the above-mentioned problems, and to detect torsional vibration and longitudinal vibration at the same position at the same time by the same method, and to perform reliable long-term remote monitoring without frequent calibration. It is an object of the present invention to provide a vibration monitoring device for a power transmission shaft system capable of recording the progress thereof and outputting an alarm when the occurrence of abnormal vibration is detected.

[0006]

A vibration monitoring device for a power transmission shaft system according to the present invention is a power transmission shaft system driven by an internal combustion engine, wherein a rotation direction and an axial direction are provided at a shaft end portion of a driven power transmission shaft. An accelerometer 4 for detecting an acceleration signal due to torsional vibration and longitudinal vibration, an amplifier 5 for inputting a signal detected by the accelerometer by a dedicated cable through a slip ring, and an output signal of the amplifier Then, a bandpass filter 6 that passes only a signal in a specific frequency band, an AC-DC converter 7 that inputs the signal output from the filter and converts it into a DC signal, and a signal that is input from the converter And a monitor recorder with an alarm device 8 that outputs an alarm when the input signal level exceeds the appropriate levels of the torsional vibration and the longitudinal vibration that are stored in advance. It is characterized in that by comprising.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a structural explanatory view of a vibration monitoring device for a power transmission shaft system driven by an internal combustion engine according to an embodiment of the present invention. The configuration and operation will be described below with reference to FIG.

In FIG. 1, 1 is an internal combustion engine which is a power source, 2 is a generator driven by the internal combustion engine 1, 3 is a rotating shaft of the generator, and 4 is an accelerometer for transmitting a detection signal through a slip ring. 5 is a high-sensitivity amplifier, 6 is a bandpass filter, 7 is an AC-DC converter, and 8 is a monitor recorder with an alarm device.

As shown in FIG. 1, the crankshaft of the internal combustion engine 1 is directly connected to the rotary shaft 3 of the generator 2 so that the axial torque is transmitted and the torsional vibration and the longitudinal vibration of the crankshaft cause the rotation of the generator 2. It is transmitted to axis 3. By attaching the accelerometer 4 to the end of the rotary shaft 3 in the rotational direction and the axial direction, the acceleration signal due to the torsional vibration and the acceleration signal due to the longitudinal vibration are simultaneously detected.

The output signal of the accelerometer 4 is conveyed to a high-sensitivity amplifier 5 via a slip ring by a dedicated cable and amplified to an appropriate level as a measurement signal. The signal amplified by the amplifier 5 is decomposed into a signal of a required frequency component by the bandpass filter 6.

The decomposed signal is converted into a DC signal by the AC-DC converter 7, inputted to the monitor recorder 8 with an alarm device, and continuously recorded. When the level of the input signal exceeds the levels of the normal values of the torsional vibration and the longitudinal vibration stored in advance, the monitor recorder determines that abnormal vibration has occurred in the shaft system and issues an alarm.

The output signal of the accelerometer 4 is input to the highly sensitive amplifier 5 via the slip ring, but a dynamic strain gauge can also be used as the amplifier here. In addition, the alarm monitor recorder 8 is provided with a bandpass filter circuit and an AC
-It is also possible to incorporate a DC conversion circuit,
Operability can be improved.

[0013]

According to the present invention, the following effects can be obtained. (1) By installing an accelerometer in the rotational direction and the axial direction at the end of the shaft system, torsional vibration and longitudinal vibration can be detected at the same position at the same time by the same method, and the peripheral devices can be unified. (2) As a sensor for detecting vibration, we decided to use an accelerometer instead of a strain gauge. This eliminates the need for frequent calibration and enables reliable long-term monitoring.

(3) The detected acceleration signal is conveyed by a dedicated cable via the slip ring. This enabled stable long-term remote measurement / monitoring. (4) By using a monitor recorder with alarm, continuous recording and alarm output when abnormal vibration occurs are possible.

[Brief description of the drawings]

FIG. 1 is a structural explanatory view of a vibration monitoring device for a power transmission shaft system driven by an internal combustion engine according to an embodiment of the present invention.

[Explanation of symbols]

4 ... Accelerometer, 5 ... Amplifier, 6 ... Bandpass filter,
7 ... AC-DC converter, 8 ... Monitor recorder with alarm device.

Claims (1)

[Claims] 1. In a power transmission shaft system driven by an internal combustion engine, an accelerometer (4) mounted on a shaft end of a driven power transmission shaft in a rotational direction and an axial direction to detect acceleration signals due to torsional vibration and longitudinal vibration. ), An amplifier (5) for carrying a signal detected by the accelerometer through a slip ring and inputting the signal, and a band-pass filter for receiving an output signal of the amplifier and passing only a signal in a specific frequency band. (6) and an AC-DC converter (7) for inputting a signal output from the filter and converting the signal into a DC signal
And a monitor recorder with an alarm device (8) which inputs a signal from the converter and continuously records the signal, and outputs an alarm when the input signal level exceeds an appropriate level of pre-stored torsional vibration and longitudinal vibration. ) And a vibration monitoring device for a power transmission shaft system.