JP2000074659A - Bend monitoring device for rotating shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To monitor the bend of a rotating shaft reliably by the hour by displaying the bending amount and phase of the rotating shaft simultaneously, thereby detecting the bending amount of the rotating shaft for rotational angle and time variation of the shaft. SOLUTION: An air gap detector 1 detects an air gap between the rotating shaft 6a of a rotating machine 6 and a stationary member such as a casing, and a phase reference signal generator 2 generates the phase reference signal of the rotating shaft 6a by a pulse signal for each turn of the rotating shaft 6a. The detected signal from the air gap detector 1 and the phase reference signal from the phase reference signal generator 2 are inputted into a monitoring device 3 through circuits 91, 92. The monitoring device 3 control-computes based on the air gap detecting signal and the phase reference signal, and simultaneously-outputs the information of the bending amount of the rotating shaft 6a and the rotational angle from the phase reference signal of the rotating shaft 6a, or the information of the phase converted into the signal which indicates a phase difference. The information of the air gap detecting value and the information of the phase are displayed simultaneously, thus it is possible to grasp the time variation in the bend.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft bending monitoring device for monitoring a bending state of a rotating shaft for a rotating machine such as a steam turbine and a gas turbine.

[0002]

2. Description of the Related Art In a relatively long rotating shaft such as a steam turbine rotor and a gas turbine rotor, the state of bending of the rotating shaft is monitored. As means for detecting and monitoring the bending of the rotating shaft, conventionally, a gap between the rotating shaft and a fixed member such as a casing is measured, and a difference between a maximum peak value and a minimum peak value thereof is calculated, and the eccentricity is calculated. Means for indicating as quantities are provided.

FIG. 1 shows the overall configuration of a shaft bending monitoring device for detecting and monitoring the rotation shaft bending. In FIG. 1, reference numeral 6 denotes a rotating machine such as a steam turbine, a gas turbine, an electric motor, and an axial compressor, and 6a denotes a rotating shaft of the rotating machine 6. 1 is a gap detector for detecting a gap between the rotating shaft 6a of the rotating machine 6 and a fixed member such as a casing, and 2 generates a phase reference signal of the rotating shaft 6a by a pulse signal for each rotation of the rotating shaft 6a. Phase reference signal generator,
The detection signal from the gap detector 1 and the phase reference signal from the phase reference signal generator 2 are input to the monitoring device 3 via lines 91 and 92. The monitoring device 3 performs control / calculation described later based on the gap detection signal and the phase reference signal,
It outputs bending amount information of the shaft 6a.

FIGS. 15 and 16 show a prior art of the shaft bending monitoring device 3, FIG. 15 is a control block diagram thereof, and FIG. 16 is a flowchart showing control / calculation means. In FIG. 15, reference numeral 31 denotes a sample data storage unit which temporarily stores the gap detection value G input from the gap detector 1. Reference numeral 32 denotes a rotation component extraction unit which extracts only a bending amount component of the rotation axis (hereinafter, simply referred to as an axis) from a gap value of the rotation axis (hereinafter, simply referred to as an axis) 6a.
Consists of a bandpass filter.

[0005] Reference numeral 41 denotes a pulse signal generating unit, based on the phase reference signal input from the phase reference signal generator 2, and based on the axis 6.
A pulse signal is generated for each rotation of a. Reference numeral 42 denotes a rotation frequency conversion unit that converts the rotation cycle of the shaft 6a into rotation frequency information.

Numeral 34 denotes an eccentricity calculating unit which calculates the air gap G based on the bending component extracted by the rotation component extracting unit 32.
Is calculated by calculating the difference between the maximum peak and the minimum peak, or the effective value and the average value.
Reference numeral 37 denotes a smoothing processing unit for organizing the calculation result of the eccentric amount into a signal such as a smooth average value. 38 is an output information conversion unit,
The calculation result of the amount of eccentricity is converted into a display form of a bending amount based on an analog signal or a digital amount.

Next, a description will be given of the control operation means in the prior art with reference to FIGS. The monitoring device 3
The gap G between the gap detector 1 and the shaft 6a and the fixed member
, And a phase reference signal K is input from the phase reference signal generator 2. The sample data storage unit 31 stores the sample data of the gap G, that is, the detected value, using the pulse from the pulse signal generation unit 41 as a selection section for data sample measurement. That is, in the sample data storage unit 31, the detection data of the gap G in the period (cycle): Δt from the time of generation of the pulse to the next pulse is sequentially stored (steps (1) and (2)).

The rotation component extraction unit 32 measures the rotation period Δt of the shaft 6a from the pulse signal generation unit 41 (step (3)), and determines the rotation frequency from the reciprocal of the period Δt (step (4)). ). Then, the rotation component extraction unit 32 removes only the rotation frequency of the shaft 6a, that is, the above noise by passing the rotation frequency through a low-pass filter or a band-pass filter whose center frequency changes. And the shaft 6a
Only the bending amount information of the shaft 6a, which changes each time is rotated, is extracted (step (5)).

The eccentric amount calculating section 34 detects an upper limit peak value G ₁ and a lower limit peak value G ₂ from the detected value of the gap G corresponding to one cycle of one rotation, and a difference ΔG between these two peak values is obtained.
G ₁ −G ₂ is calculated to obtain the peak-to-peak eccentricity (ie, ΔG) (step (7)). Alternatively, seeking simple average between the upper peak value G ₁ and the lower peak value G _2, or an averaged value eccentricity. In the smoothing processing section 37, the eccentricity amount is processed into a smooth signal by a first-order backward filter based on the eccentricity amount calculation value from the calculating section 34 (step (20)). In the output information converter 38, the eccentricity ΔG
Is converted into an information display form by a bending amount based on an analog signal or a digital amount and output (step (8)).

[0010]

In detecting and monitoring the bending of the rotary shaft 6a, in the case of the prior art shown in FIGS. 15 to 16, the maximum peak value and the minimum gap of the gap between the rotary shaft 6a and the fixed member are determined. The difference between the peak values is detected, and the rotation axis 6a is detected.
Is used as a phase reference signal to detect and monitor the bending of the rotating shaft 6a from the amount of eccentricity of the rotating shaft 6a for each rotation. The relationship with the bending of the rotating shaft 6a cannot be detected, and therefore, it is not possible to detect the direction or the time change of the rotating angle of the rotating shaft 6a where the rotating shaft 6a is bent.

For this reason, in the case of the conventional technique,
There is a problem that the operation management and the strength management of the rotating machine cannot be sufficiently performed, for example, it is not possible to take sufficient measures for various problems caused by the bending of the rotating shaft 6a.

The present invention has been made in view of the above-mentioned problems of the prior art, and is capable of detecting the amount of bending of the rotating shaft with respect to the rotation angle and time of the rotating shaft so that the bending of the rotating shaft can be monitored in units of time and reliably. It is an object of the present invention to provide an apparatus for monitoring bending of an axis.

[0013]

According to a first aspect of the present invention, there is provided a gap detector for detecting a gap between a rotating shaft and a fixed member, and a phase detector based on a phase reference signal of the rotating shaft. , A bend amount calculation means for calculating a bend amount of the rotary shaft from the detected value of the gap, and an output means for simultaneously displaying the bend amount and the phase. A bend monitoring device for rotating shaft is proposed.

[0014] The second invention is the first invention, wherein
The bending amount calculating means is configured to calculate an eccentric amount of the rotating shaft from a difference between a maximum peak value and a minimum peak value for each rotation of the rotating shaft of the gap, or an effective value or an average value, and The calculating means is configured to calculate a phase difference from the phase reference signal.

According to a third aspect of the present invention, in the first aspect, the bending amount calculating means calculates an eccentric amount from the gap as polar coordinates.

In a fourth aspect based on the first aspect, the output means displays the amount of bending of the rotating shaft as a detected value of the air gap and calculates the display of the phase based on the phase reference signal. It is configured to display the phase difference.

In a fifth aspect based on the first aspect, the output means superimposes the phase reference signal on the detected value of the air gap and displays the amount of bending and the phase in one display form. Be done.

According to this invention, the information on the detected value of the gap between the rotating shaft and the fixed member and the information on the phase calculated from the phase reference signal are simultaneously displayed, so that the amount of bending of the shaft due to the gap is provided. At the same time, it is possible to correctly display the state of change relative to the phase and time of axis bending. Thus, it is possible to prevent various troubles caused by the bending of the shaft without using a special measuring device.

In particular, according to the fourth aspect of the present invention, since the bending amount and the phase angle information thereof can be obtained directly, even in the case of urgent need, the bending information of the shaft can be obtained quickly.

According to the fifth aspect of the present invention, since the air gap and the phase can be displayed in one display form, the bending and phase of the shaft can be simultaneously displayed and recorded without adding a conventional recording instrument. Can be.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

FIG. 1 is an overall configuration diagram of a rotation shaft bending monitoring device according to a first embodiment of the present invention, FIG. 2 is a block diagram of the bending monitoring device, and FIG. 3 is a control flowchart thereof. In FIG. 1, reference numeral 6 denotes a rotating machine such as a steam turbine, a gas turbine, an electric motor, and an axial compressor, and 6a denotes a rotating shaft of the rotating machine 6. 1 is a gap detector for detecting a gap between the rotating shaft 6a of the rotating machine 6 and a fixed member such as a casing, and 2 generates a phase reference signal of the rotating shaft 6a based on a pulse signal for each rotation of the rotating shaft 6a. A phase reference signal generator, and a detection signal from the air gap detector 1 and a phase reference signal from the phase reference signal generator 2 are transmitted through lines 91 and 92.
Is input to the monitoring device 3.

The monitoring device 3 performs a control operation as described later based on the air gap detection signal and the phase reference signal.
It simultaneously outputs the bending amount information of the rotating shaft 6a and the phase information converted into a signal representing a rotation angle, that is, a phase difference from a phase reference signal of the rotating shaft 6a.

Next, the configuration of the monitoring device 3 will be described with reference to FIG. Reference numeral 31 denotes a sample data storage unit that temporarily stores the gap detection value G input from the gap detector 1. Reference numeral 32 denotes a rotation component extraction unit for extracting only a bending amount component of the rotation axis (hereinafter abbreviated as an axis) 6a from the detection value of the rotation axis 6a, and includes a low-pass filter and a band-pass filter. Reference numeral 33 denotes a peak detection unit which detects the position in the sample data of the peak value in the gap detection value G of the shaft 6a output from the rotation component extraction unit 32.

Numeral 34 denotes an eccentricity calculating unit which produces the eccentricity of the shaft 6a by calculating the difference between the peaks of the air gap of the shaft 6a, the effective value, and the average value. Numeral 38 denotes an output information converter (A), which outputs the axis 6
The amount of eccentricity a is converted into a display form of a bending amount by an analog signal or a digital amount. A pulse signal generator 41 generates a pulse signal for each rotation of the shaft 6a based on the phase reference signal K input from the phase reference signal generator 2.

Reference numeral 42 denotes a rotation frequency conversion unit which converts the rotation cycle of the shaft 6a into rotation frequency information. Reference numeral 43 denotes a phase difference detector, which outputs the phase reference signal K from the phase reference signal generator 2.
Is detected, the phase difference between the peak value of the gap G and the reference position of the axis 6a is detected. An output information converter (B) 48 converts the phase difference from the phase difference detector 43 into an analog signal or a phase information form based on a digital amount.

As described above, the monitoring device 3 according to the first embodiment of the present invention differs from the conventional technology shown in FIGS. 15 and 16 in that the peak detector 33, the phase difference detector 43, and the output information A conversion unit (B) 48 is added.

Next, the operation of the shaft bending monitoring apparatus according to the first embodiment will be described. FIG. 4 shows the gap detector 1.
Shows the relationship between the time t and the gap G detected by the phase reference signal K and the phase reference signal K generated by the phase reference signal generator 2. Rotary shaft 6 in rotary machine 6 using a heat fluid such as a steam turbine
The bending of a is mainly caused by the temperature difference between the upper portion of the heated shaft 6a and the lower portion where cooling is progressing when the machine is stopped, and the bending is caused by the gap detector. 1 is detected as a change in the gap G between the shaft 6a and the casing (fixing member).

As shown in FIG. 4, the change of the gap G is a vibration waveform having one cycle of one rotation of the shaft 6a. Therefore, if the difference ΔG between the maximum peak value G ₁ and the minimum peak value G _{2 of} such a waveform is calculated, the swing width due to the bending of the shaft 6 a, that is, the eccentric amount of the peak value G ₁ versus the peak value G ₂ can be obtained. . In FIG. 4, this eccentric amount ΔG
Is a period (period) Δt during which the shaft 6a makes one rotation.

The air gap signal is mechanically applied to the surface of the shaft 6a.
Alternatively, a signal containing magnetic and electric noises of the air gap detector 1 is obtained. In order to remove such noises, a low-pass filter for attenuating a frequency component equal to or higher than the bending fluctuation frequency as the rotation component extraction unit 32, or the shaft 6a. , A band-pass filter that passes only the frequency corresponding to the rotation period is used. Then, using the pulse interval from the phase reference signal generator 2, that is, the period Δt as the rotation period information of the shaft 6a, and following the eccentric amount ΔG as shown in FIG. 4, the time change of the bending amount of the shaft 6a is obtained. Can be

The axis 6a is used as the phase reference signal.
If the period of one rotation, ie, the period Δt, is not available, 1
The peak values G ₁ and G _{2 are} detected at regular time intervals such as minutes, and the eccentricity ΔG is calculated. In addition, the eccentricity ΔG can be represented by an effective value based on a root-mean-square process or an average calculation result. In this case, a phase reference signal at a constant time interval similar to the above is used.

Next, a control calculation procedure of the monitoring device 3 in the first embodiment will be described with reference to FIGS. To the monitoring device 3, a detection signal for each time of the gap G between the shaft 6 a and the fixed member is input from the gap detector 1, and a phase reference signal K is input from the phase reference signal generator 2. .

The sample data storage section 31 stores the sample data with the gap G, that is, the detected value, using the pulse from the pulse signal generation section 41 as a selection section for data sample measurement. That is, in the sample data storage unit 31, the detection data of the gap G in a period Δt from the time of the pulse generation to the next pulse is sequentially stored (steps (1) and (2)).

The rotation component extraction unit 32 measures the rotation period Δt of the shaft 6a from the pulse signal generation unit 41 (step (3)), and determines the rotation frequency from the reciprocal of the period Δt (step (4)). ). Then, the rotation component extraction unit 32 removes only the rotation frequency of the shaft 6a, that is, the above noise by passing the rotation frequency through a low-pass filter or a band-pass filter whose center frequency changes. And the shaft 6a
Only the bending amount information of the shaft 6a, which changes each time is rotated, is extracted (step (5)).

The peak detector 33 detects either the upper limit peak G ₁ or the lower limit peak G ₂ of the gap G, and obtains a gap data sample corresponding to one rotation cycle of the axis 6 a of the detected peak value. The position in the selected section is detected (step (6)). In eccentricity calculating unit 34, one revolution 1 corresponding to periods wherein detecting the upper peak value G ₁ from the detection value of the air gap G and the lower peak value G _2, differences .DELTA.G = G ₁ -G of both peak values ₂ is calculated to obtain the peak-to-peak eccentricity (that is, ΔG) (step (7)). Alternatively, seeking simple average between the upper peak value G ₁ and the lower peak value G _2, or an averaged value eccentricity. The output information conversion unit (A) 38 converts the eccentricity ΔG into a bending amount information display form based on an analog signal or a digital amount and outputs it (step (8)).

On the other hand, in the phase difference detecting section 43, the position of the peak value (G ₁ or G ₂ ) of the gap G detected by the peak detecting section 33 and one per rotation from the pulse signal generating section 41. The time difference Td from the pulse generation to the peak value of the gap G is obtained by the following equation (1) based on the pulse generation cycle (step (9)). Td = [(position of peak value of gap during sample selection period) / (total number of sample data)] × period of one rotation (generation period) (1) The phase difference (angle) Ф of the peak value is calculated by the equation (2) (step (10)). Ф = ω × Td (2) where ω is the rotational angular velocity of the shaft 6a. In the output information converter (B) 48, the phase difference Ф calculated by the equation (2) is used.
Is converted into an analog signal or a phase information display form based on a digital amount and output (step (11)).

FIG. 5 is a block diagram of a rotation shaft bending monitoring apparatus according to a second embodiment of the present invention, and FIG. 6 is a control flowchart thereof. This embodiment differs from the first embodiment in the functions of the phase difference detection unit 43 and the output information return unit 47, and additionally includes an XY conversion operation unit 46. That is, the phase difference detector 43 detects a time difference between a point in time when one pulse is generated per rotation from the pulse signal generator 41 and a point in time when the gap G reaches a peak of a sine waveform (or a cosine waveform) as a phase difference. .

Reference numeral 46 denotes an XY conversion operation unit which detects the eccentricity calculated by the eccentricity operation unit 34 and the phase difference detection unit 43.
Is converted into the X-axis and Y-axis coordinate values (polar coordinates) by the following equations (3) and (4). x = Acosφ (3) y = Asinφ (4) where A is the amplitude of the eccentricity and φ is the phase difference. An output information converter 47 converts the eccentricity and the x and y coordinate values of the phase difference into a display form of an analog signal or a digital quantity.

Next, the operation of monitoring the bending of the shaft according to the second embodiment will be described. FIG. 7 shows the relationship between the gap G, the phase reference signal K, and the amount of eccentricity a of the shaft 6a based on the gap G in this embodiment, and FIG. 8 shows a vector diagram of the amount of eccentricity. In this embodiment, noise is removed from the change in the gap G between the shaft 6a and the fixed member, and the waveform of the amount of eccentricity is represented by a sine wave in polar coordinates.

That is, as shown in FIG. 7, if the amplitude of the eccentricity is A and the phase difference from the phase reference signal is φ, the relationship between the eccentricity a and the time t is expressed by equation (5). a = Asin {ω (t−Td) + π / 2} (5) where Td is the time difference between the point of the maximum amplitude (peak value) A and the phase reference signal from the axis phase reference signal generator 2; ω is the rotational angular velocity of the shaft 6a. The waveform in which the amount of eccentricity a reaches the positive (plus) side peak when the phase reference signal pulse is generated is represented by Expression (6). a = Asin {ωt + π / 2} (6) Therefore, the waveform of the above equation (5) delayed by the time difference Td from the phase reference signal is obtained from the equation (6) by the phase difference φ = ω · Td.
The waveform is the same as the waveform shifted by only

From this, the phase difference φ corresponding to the time difference Td, that is, the phase difference of the peak value of the eccentricity a from the phase reference of the axis 6a is obtained. Further, the eccentricity a may be represented by a vector on polar coordinates as shown in FIG.
That is, the amount of eccentricity is output by performing XY coordinate conversion by the above equations (3) and (4) so that vector recording can be performed by the XY coordinate recorder. x = Acosφ (3) y = Asinφ (4)

Next, a control calculation procedure in the monitoring device 3 according to the second embodiment will be described with reference to FIGS. With the same operation process as the first embodiment,
The peak-to-peak eccentricity ΔG is calculated (step (7)), and the phase difference の of the peak value is calculated (step (10)).

The eccentricity ΔG and the phase difference ピ ー ク between the peak values are input to an XY conversion operation unit 46. The XY conversion operation unit 46 converts the eccentricity ΔG and the phase difference に into coordinate values of the X axis and the Y axis. That is, the eccentricity and the phase difference are expressed by XY as shown in the vector expressions of the above-mentioned equations (3) and (4), where A is the amplitude of the eccentricity and φ is the phase difference of the amplitude A.
A coordinate transformation is performed (step (11)). x = Acosφ (3) y = Asinφ (4) The output information conversion unit 47 converts the polar coordinate display x, y into a display form of x, y coordinate values based on an analog signal or a digital amount (step (12)). )).

FIG. 9 is a control block diagram of a shaft bending monitoring apparatus according to a third embodiment of the present invention. In this embodiment, the following elements are added in place of the peak detector 33 and the phase difference detector 43 in the first embodiment shown in FIGS. Reference numeral 35 denotes a gap value scale conversion unit, and the rotation component extraction unit 3
The correction is performed based on the bending component (gap measurement value) of the shaft 6a extracted in step 2 based on the mounting position of the gap detector 1, and converted into a gap value scale serving as a display reference. A phase difference signal generator 44 generates a phase difference signal for displaying phase information based on the number of pulses per rotation of the shaft 6a from the pulse signal generator 41.

Next, based on FIG. 9 and FIG.
The operation of the shaft bending monitoring device according to the embodiment will be described.
In this embodiment, the time change of the bending amount of the shaft 6a can be directly observed based on the air gap detection signal from the air gap detector 1 based on the bending amount of the shaft 6a. That is, as shown in FIG. 11, the phase reference signal K from the phase reference signal generator 2 is
Is set as the rotation cycle of the shaft 6a, and a phase difference signal β from a phase reference point in which the phase changes continuously between pulses is generated. Then, the phase difference signal β is made to correspond to the gap detection signal G indicating the amount of bending of the shaft 6a which is simultaneously output, and the gap value at each rotation angle position of the shaft 6a, that is, the amount of bending of the shaft, is detected.

Next, a control / calculation procedure of the monitoring device 3 according to the third embodiment of the present invention will be described with reference to FIGS. With the same calculation process as in the first embodiment, the rotation component extraction unit 32 extracts the bending component (gap detection value G) of the shaft 6a (step (5)). The bending component of the gap detection value G is input to the gap value scale conversion unit 35.

The gap value scale conversion unit 35 performs an offset correction calculation between the mounting position of the gap detector 1 and the display reference position of the amount of bending, and performs measurement by mounting the gap detector 1 at another location. A display value that can be compared at the same level as (step (13)). That is, [gap display value = gap measurement value−mounting position offset amount of gap detector 1].

On the other hand, the pulse number signal per one rotation of the shaft 6a from the pulse signal generation unit 41 similar to the first embodiment is input to the phase difference signal generation unit 44. The output information conversion section (A) 38 converts the corrected air gap value into a bending amount display form based on an analog signal or a digital amount and outputs it (step (14)).

On the other hand, the phase difference signal generator 44 generates a sawtooth phase difference signal β as shown in FIG. 11 from the following equation (5) based on the pulse number signal (step (1)
5)). β = B × (1 / rotation cycle) · t (5) where B is the maximum phase difference. Output information converter (B) 4
In step 8, the phase difference signal is converted into an analog signal or a phase difference signal based on a digital amount and output (step (1)
6)).

A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 12 is a control block diagram of the fourth embodiment, FIG. 13 is a control calculation flowchart, and FIG. 14 is a diagram for explaining the operation. In this embodiment, a signal waveform synthesizer 36 is added to the gap processing system of the third embodiment, and a marker signal generator 45 for synthesis is added to the phase processing system. The output is input to the signal waveform synthesizer 36.

That is, in the control block diagram shown in FIG. 12, reference numeral 36 denotes a signal waveform synthesizing unit. The signal waveform synthesizing unit 45, which will be described later, adds a gap indication signal from the gap value scale conversion unit 35 in the third embodiment to a gap indication signal. Are synthesized. Numeral 45 denotes a marker signal generator for synthesis, which generates a marker signal for signal synthesis based on the pulse signal per rotation of the shaft 6a from the pulse signal generator 41.

Next, based on FIG. 12 and FIG.
The operation of the bending amount monitoring device according to the embodiment will be described.
When the detection signal of the gap G from the gap detector 1 is recorded on the pen recorder, as shown in the relationship between the gap indication signal and the time t in FIG. 14, the phase reference point b is marked on the recording of the bending amount. It will be. The air gap indication combined signal including such a phase reference point is a method in which the value of the bending value signal (air gap signal) is reduced to the lower limit of the zero value or is shifted to the upper limit only at the moment when the pulse is generated by the phase reference signal generator 2. (Part b in FIG. 14).

Next, a control / calculation procedure of the monitoring device 3 according to the fourth embodiment of the present invention will be described with reference to FIGS. The air gap value (step (13)) whose scale has been corrected by the same calculation process as in the third embodiment is input to the signal waveform synthesizing unit 36. On the other hand, the marker signal generator for synthesis 4
In 5, the position of the pulse generation from the pulse signal generator 41 is used as a marker.

That is, as shown by b in FIG. 14, a marker signal is a large negative signal which reduces the value of the air gap display signal to the lower limit of zero, or a large positive signal which is deviated to the upper limit. Occurs (step (1
4)).

The signal waveform synthesizing section 36 synthesizes the marker signal (b in FIG. 14) from the synthesizing marker signal generating section 45 on the scale-corrected air gap value waveform. Such an air gap display signal is created (step (15)). Then, the output information converter 38 converts the air gap display signal into an analog signal or a digital amount indicating the amount of bending.

[0056]

As described above, according to the present invention, the amount of bending of the rotating shaft can be correctly displayed in relation to the phase and time without requiring any special instrument. As a result, it is possible to prevent the occurrence of troubles due to the bending of the shaft without using separate measuring devices, and to maintain the safety and durability of the rotating machine.

According to the fourth aspect of the present invention, since the information on the amount of bending and the information on the phase can be obtained directly, an urgent countermeasure can be made without any trouble.

Further, according to the fifth aspect, the air gap and the phase can be displayed in one display form, and the bending of the shaft and the phase can be simultaneously displayed without adding a conventional recording instrument.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a bending monitoring device for a rotating machine according to an embodiment of the present invention.

FIG. 2 is a control block diagram of the rotation shaft bending monitoring device according to the first embodiment of the present invention.

FIG. 3 is a control flowchart of the monitoring device according to the first embodiment.

FIG. 4 is a diagram illustrating an operation in the first embodiment.

FIG. 5 is a control block diagram of a rotation shaft bending monitoring device according to a second embodiment of the present invention.

FIG. 6 is a control flowchart of a monitoring device according to the second embodiment.

FIG. 7 is a diagram (part 1) for explaining operation in the second embodiment.

FIG. 8 is a diagram (part 2) for explaining the operation in the second embodiment.

FIG. 9 is a control block diagram of a rotation shaft bending monitoring device according to a third embodiment of the present invention.

FIG. 10 is a control flowchart of a monitoring device according to the second embodiment.

FIG. 11 is a diagram for explaining the operation in the second embodiment.

FIG. 12 is a control block diagram of a rotation bending monitoring device according to a fourth embodiment of the present invention.

FIG. 13 is a flowchart of the monitoring device according to the fourth embodiment.

FIG. 14 is a diagram for explaining the operation in the fourth embodiment.

FIG. 15 is a diagram corresponding to FIG. 2 showing a conventional technique.

FIG. 16 is a diagram corresponding to FIG. 3 showing a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 air gap detector 2 phase reference signal detector 3 monitoring device 6 rotating machine 6 a rotation axis 31 sample data storage unit 32 rotation component extraction unit 33 peak detection unit 34 eccentricity detection unit 35 air gap value scale conversion unit 36 signal waveform synthesis unit 38 Output information conversion unit (A) 41 Pulse signal generation unit 42 Rotation frequency conversion unit 43 Phase difference detection unit 44 Phase difference signal generation unit 45 Marker signal generation unit for synthesis 46 XY conversion operation unit 47 Output information conversion unit 48 Output information Conversion unit (B)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F069 AA21 BB08 BB40 DD22 GG04 GG06 HH15 HH30 JJ17 JJ25 NN03 NN04 NN09 NN26 QQ05 QQ12 2G024 AD02 BA11 CA05 CA06 CA08 DA09 FA11

Claims (5)

[Claims] A gap detector for detecting a gap between a rotating shaft and a fixed member; a phase calculating means for calculating a phase based on a phase reference signal of the rotating shaft; a bending of the rotating shaft from a detected value of the gap. A bending monitoring device for a rotating shaft, comprising: a bending amount calculating means for calculating an amount; and an output means for simultaneously displaying the bending amount and the phase. 2. The method according to claim 1, wherein the bending amount calculating unit calculates a difference between a maximum peak value and a minimum peak value for each rotation of the rotation axis of the gap,
Alternatively, the eccentricity of the rotating shaft is calculated from an effective value and an average value, and the phase calculating means is configured to calculate a phase difference from the phase reference signal. Bend monitoring device. 3. The bending monitoring apparatus according to claim 1, wherein said bending amount calculating means is configured to calculate an eccentric amount from said gap as polar coordinates. 4. The output means is configured to display the amount of bending of the rotating shaft as a detected value of the gap, and to display the phase with a phase difference calculated based on the phase reference signal. The bending monitoring device for a rotating shaft according to claim 1. 5. The output means superimposes the phase reference signal on the detected value of the gap to determine the bending amount and the phase by one.
2. The display according to claim 1, wherein the display is configured to be displayed in one of two display forms.
A device for monitoring bending of a rotating shaft according to the above description.