JP7228540B2 - Signal processor for rotor electrical run-out measuring device, rotor electrical run-out measuring device, and rotor electrical run-out measuring method - Google Patents

Description

The present invention relates to a signal processing device for a rotor electrical run-out measuring device, a rotor electrical run-out measuring device using the same, and a rotor electrical run-out measuring method.

Vibration measurement of a rotor using a non-contact sensor is used to monitor the state of an electric motor, generator, or the like during operation (see Patent Document 1). The vibration value is represented by the displacement (μmP−P) of the site illuminated by the sensor. In vibration measurement using a non-contact sensor, the allowable value varies depending on the standard, but it is required to minimize the rotor electrical deflection as much as possible. After the assembly of the rotating machine (completed state), it is difficult to repair the electrical deflection, so the electrical deflection is inspected in the manufacturing process of the rotor.
The rotor electrical deflection is the difference between the output voltage corresponding to the distance that should be originally obtained and the output voltage fluctuating due to the material, surface structure, and unevenness of the rotor. Vibration values also vary with rotational speed, primarily due to static or dynamic imbalance of the rotor. On the other hand, the rotor electrical deflection is a characteristic of each rotor and does not change according to the rotation speed.

Japanese Patent Publication No. 7-119825

Since the relative position of the measuring device with respect to the target rotor changes, measurement using an eddy current displacement meter is usually performed as a non-contact measuring method.

Here, compared to the gap (initial GAP voltage) between the target rotor and the eddy-current displacement gauge, the degree of voltage change due to the unevenness or texture of the rotor surface is extremely small. Therefore, sufficient accuracy cannot be ensured by simply reading the change in the gap between the rotor and the eddy-current displacement gauge.

For this reason, for example, the output of an eddy current displacement sensor is biased with a negative DC component, the differential signal is amplified and displayed, and the bias is manually adjusted while viewing the display.

FIG. 8 is a flowchart showing a conventional example of a rotor shaft runout measuring method. An example of a conventional measuring method using a measuring device is as follows.

First, in the measuring device, an eddy current displacement meter detects a gap signal (step S01). Measure the distance between the eddy current displacement meter and the object to be measured.

Next, the measurer adjusts the bias value with the adjustment knob (step S02).

The measuring device subtracts the bias value from the distance signal detected by the eddy current displacement meter (step S03). By reducing the bias value, mainly the variation remains.

Next, the measurer performs gain adjustment (step S04). In the gain adjustment, it is expected that the gain will be increased to the extent that the fluctuation can be sufficiently confirmed on the screen. The necessity of gain adjustment is determined (step S06), and steps S04 to S06 are repeated.

If the bias value adjusted in step S02 is not appropriate, the waveform displayed on the display unit will still have a large DC component, and the fluctuation cannot be expanded sufficiently. Thus, the measurer determines whether the bias value is appropriate (step S07).

If the measurer cannot determine that the bias value is appropriate (step S07 NO), steps S02 through step S07 are repeated.

The above is the procedure to be followed for a single diameter measurement point. The measurer needs to repeat the above procedure each time the diameter of the object to be measured changes. Conventionally, when measuring the runout of the rotor shaft using an eddy current displacement gauge, the initial DC voltage component cut adjustment, that is, the bias value subtraction adjustment, was manually performed. I needed it.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to simplify the runout measurement of the rotor shaft and shorten the time.

In order to achieve the above object, a signal processing apparatus according to the present invention includes an average value calculator that receives a measured gap signal and outputs an average value, and an average value calculator that subtracts the average value from the gap signal and outputs a difference. A subtractor and an amplifier for amplifying the difference are provided, and the average value calculator includes an integrator that receives the measured gap signal and outputs an integral value, and a time counter that counts and outputs the measurement time. and a divider that receives the integral value and the measurement time and outputs a result of dividing the integral value by the measurement time as an average value.

Further, a rotor electrical run-out measuring apparatus according to the present invention includes an eddy current displacement gauge for detecting a gap with a rotor to be measured, the signal processing device described above, and an output from the signal processing device being displayed. and a display device.

Further, the rotor electrical run-out measuring method according to the present invention includes a detection step of detecting a gap with respect to the rotor to be measured, and an average value calculation unit receiving the measured gap signals and outputting an average value. A subtraction step in which a subtractor subtracts the average value from the gap signal to output a difference, and an amplification step in which an amplifier amplifies the difference.

According to the present invention, the runout measurement of the rotor shaft can be simplified and the time shortened.

1 is a conceptual diagram showing the configuration of a rotor electrical runout measuring device according to a first embodiment; FIG. 3 is a block diagram showing the configuration of a signal processing circuit of the rotor electrical run-out measuring device according to the first embodiment; FIG. FIG. 4 is a flow chart showing the procedure of the rotor electrical runout measuring method according to the first embodiment; FIG. 10 is a first screen for explaining the effect of the rotor electrical runout measuring device according to the first embodiment; FIG. FIG. 11 is a second screen for explaining the effect of the rotor electrical runout measuring device according to the first embodiment; FIG. FIG. 9 is a block diagram showing the configuration of a signal processing circuit of a rotor electrical runout measuring device according to a second embodiment; FIG. 11 is a block diagram showing the configuration of a signal processing circuit of a rotor electrical run-out measuring device according to a third embodiment; FIG. 2 is a flow chart showing a conventional example of a rotor electrical runout measuring method;

DESCRIPTION OF THE PREFERRED EMBODIMENTS A signal processing device, a rotor electrical run-out measuring device, and a rotor electrical run-out measuring method of a rotating electric machine rotor electrical run-out measuring device according to embodiments of the present invention will be described below with reference to the drawings. Here, parts that are the same or similar to each other are denoted by common reference numerals, and overlapping descriptions are omitted.

[First embodiment]
FIG. 1 is a conceptual diagram showing the configuration of a rotor electrical runout measuring device 10 according to the first embodiment. FIG. 1 also shows the positional relationship between the object 1 to be measured and the rotor electrical runout measuring device 10 .

A rotor, which is an object to be measured 1, is a rotating body having a plurality of diameters in the axial direction and having a rotation axis C as the center of rotation. The object 1 to be measured is supported at one end in the axial direction by a support portion 3 and is rotatably supported at the other end by a rotary drive portion 2 .

The rotor electrical runout measuring device 10 has an eddy current displacement gauge 11 , a display device 12 , a movement driving section 15 , a rail 16 and a signal processing device 100 . The rotor electrical runout measuring device 10 outputs a voltage corresponding to the unevenness and structure of the rotor surface in the circumferential direction as the rotor, which is the object to be measured 1, rotates, and the amplitude of the voltage runout is visually observed on the display device. make it possible.

The eddy current displacement gauge 11 measures the gap with the object 1 to be measured, that is, the distance D between itself and the object 1 to be measured.

The rail 16 is arranged parallel to the rotation axis C of the object 1 to be measured. The movement drive unit 15 supports the eddy current displacement gauge 11 . The movement drive unit 15 is mounted on rails 16 and moves on the rails 16 . As a result, the eddy current displacement gauge 11 can measure the gap along the object 1 to be measured.

A gap signal measured by the eddy current displacement gauge 11 is output to the signal processing device 100 . The signal processing device 100 processes the received gap signal and outputs the result to the display section 12 for display by the display section 12 .

FIG. 2 is a block diagram showing the configuration of the signal processing device 100 of the rotor electrical runout measuring device 10 according to the first embodiment.

Signal processing apparatus 100 has receiving section 110 , average value calculating section 120 , subtractor 130 and amplifier 140 .

The receiver 110 receives the gap signal measured by the eddy current displacement gauge 11, amplifies it as necessary, and converts it into a form that facilitates signal processing. For example, if the received gap signal is a current signal, it is converted into a voltage signal. Alternatively, for example, the analog signal is converted to a digital signal.

Reception section 110 outputs the converted result to average value calculation section 120 and subtractor 130 .

Average value calculator 120 receives the output of receiver 110 and calculates its average value.

Subtractor 130 receives the output of receiving section 110 and the output of mean value calculating section 120, and subtracts the mean value, which is the output of mean value calculating section 120, from the output of receiving section 110 to calculate a difference signal.

Amplifier 140 amplifies the output of subtractor 130 and outputs it to display device 12 .

Average value calculator 120 has integrator 121 , time counter 123 , and divider 124 . The integrator 121 receives the output of the receiver 110 and performs integral calculation. Time counter 123 counts the time during which integrator 121 is accepting the output of receiver 110 . Divider 124 receives the output of integrator 121 and the output of time counter 123, divides the integrated value output from integrator 121 by the time count value output from time counter 123, and calculates an average value.

FIG. 3 is a flow diagram showing the procedure of the rotor electrical runout measuring method according to the first embodiment.

First, the eddy current displacement gauge 11 detects a gap signal (step S01).

Next, the average value calculator 120 of the signal processing device 100 calculates the average value (step S12).

Next, the subtractor 130 of the signal processing device 100 subtracts the average value from the gap signal to calculate the difference signal (step S13).

Next, the amplifier 140 of the signal processing device 100 amplifies the difference signal (step S14). The display unit displays the amplified signal (step S15).

FIG. 4 is a first screen for explaining the effects of the rotor electrical runout measuring device according to the first embodiment. The first screen is the case without using the rotor electrical deflection measuring device according to the first embodiment. That is, it shows the case where a value close to the average value but not the average value is subtracted from the gap signal. In this case, since the DC component remains in the difference signal, even if the gain is increased within a range that can be confirmed on the display unit, the fluctuation cannot be sufficiently confirmed. That is, due to the limitation of the dynamic range of the display unit, for example, a memory high coder, the fluctuating voltage (AC component) cannot be extracted unless the GAP voltage (DC component) is reduced.

FIG. 5 is a second screen for explaining the effects of the rotor electrical runout measuring device 10 according to the first embodiment. The first screen is the case of the rotor electrical runout measuring device 10 according to the first embodiment. That is, it shows the case where the average value is subtracted from the gap signal. In this case, since the difference signal is only the variation, the display unit can display the result of sufficiently enlarging only the variation.

As described above, according to the rotor electrical runout measuring apparatus 10 according to the present embodiment, runout measurement of the rotor shaft can be automatically performed and high accuracy can be ensured. Time can be shortened.

[Second embodiment]
FIG. 6 is a block diagram showing the configuration of the signal processing device 100a of the rotor electrical runout measuring device according to the second embodiment.

This embodiment is a modification of the first embodiment, and the configuration of the average value calculator 120a of the signal processing device 100a is different from the average value calculator 120 in the first embodiment. Other points are the same as the first embodiment.

The average value calculator 120 a in this embodiment has an integrator 121 , a selector 122 and a divider 124 .

The integrator 121 has a first integrator 121a and a second integrator 121b. The integration time of the first integrator 121a is shorter than the integration time of the second integrator 121b. That is, for example, when the integrator is composed of a linear amplifier and a capacitor, the capacity of the capacitor of the first integrator 121a is smaller than the capacity of the capacitor of the second integrator 121b.

The selector 122 receives the output of the first integrator 121a and the output of the second integrator 121b, switches between them, and outputs the output received from the selected side. At the time of switching, the outputs of both are bumpless, that is, when one is in use, the output of the other follows and the switching is possible without fluctuation of the output.

Divider 124 divides the output from selector 122 by the time count value from time counter 123 and outputs an average value.

In the average value calculation unit 120a according to the present embodiment configured as described above, at the beginning of the integration operation of the integrator 121, the average value is initially calculated based on the integrated value by the first integrator 121a having a short integration time. When the target value is approached, the average value is calculated based on the integrated value by the second integrator 121b having a longer integration time. As a result, it is possible to shorten the time until the average value is calculated when the average value calculation is started.

The timing at which the selector 122 switches from the output of the first integrator 121a to the output of the second integrator 121b is not shown in FIG. 5, but is possible as follows.

That is, since the time required for integration for calculating the average value is proportional to the width of change when the gap D is changed from the previous gap D to the new gap D, the receiving section 110 calculates this width of change, for example, the standard Appropriate switching can be achieved by calculating the timing based on the known integration time for the change width and outputting it to the selector 122 .

As described above, according to the signal processing device 100a according to the present embodiment, it is possible to further shorten the time.

[Third embodiment]
FIG. 7 is a block diagram showing the configuration of the signal processing device 100b of the rotor electrical runout measuring device according to the third embodiment. This embodiment is a modification of the second embodiment.

The third embodiment differs from the second embodiment in that the signal processing device 100b has a reset section 150, and the other parts including the average value calculation section 120a are the same as the second embodiment. be.

Reset unit 150 has difference determination unit 151 and reset instruction unit 152 .

The difference determination unit 151 determines whether or not the absolute value of the output of the subtractor 130 is greater than a predetermined value ε. If it is determined that it is not greater than the value ε, it outputs a logical value "NO".

When the difference determination section 151 outputs “NO”, the output of the subtractor 130 is output to the amplifier 140 .

When the difference determination unit 151 outputs “YES”, it is output to the reset command unit 152 . Reset command unit 152 outputs a reset signal to integrator 121 (first integrator 121 a and second integrator 121 b ) and time counter 123 .

Integrator 121 and time counter 123 reset their output values to zero once upon receiving the reset signal.

According to the signal processing device 100b according to the present embodiment configured in this manner, continuous measurement can be performed even when the diameter changes in the axial direction, and a significant reduction in time can be achieved.

[Other embodiments]
Although the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. For example, in the third embodiment, the configuration of the average value calculator is the same as in the second embodiment, but it may be the same configuration as the average value calculator in the first embodiment.

Moreover, you may combine the characteristic of each embodiment. In addition, the embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention.

The embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and its equivalents.

DESCRIPTION OF SYMBOLS 1... Measurement object, 2... Rotation drive part, 3... Support part, 10... Rotor electrical deflection measuring device, 11... Eddy-current displacement meter, 12... Display device, 15... Movement drive part, 16... Rail, 100 Signal processing device 110 Reception unit 120, 120a Average value calculation unit 121 Integrator 121a First integrator 121b Second integrator 122 Selector 123 Time counter 124 Divider 130 Subtractor 140 Amplifier 150 Reset unit 151 Difference determination unit 152 Reset instruction unit

Claims (6)

an average value calculator that receives the measured gap signals and outputs an average value;
a subtractor that subtracts the average value from the gap signal and outputs a difference;
an amplifier that amplifies the difference;
and
The average value calculation unit is
an integrator that accepts the measured gap signal and outputs an integrated value;
a time counter that counts and outputs the measurement time;
a divider that receives the integral value and the measurement time and outputs a result of dividing the integral value by the measurement time as an average value;
A signal processing device for a rotor electrical run-out measuring device, characterized by comprising: The integrator has a first integrator with a short integration time and a second integrator with a long integration time,
The average value calculation unit further includes a selector that switches from integration by the first integrator to integration by the second integrator and outputs an integral value to the divider.
2. The signal processing device for the rotor electrical run-out measuring device according to claim 1, wherein: a difference determination unit that receives the difference from the subtractor and determines whether or not it is greater than a predetermined value;
a reset command unit that resets the average value calculation unit when the difference determination unit determines that the difference is larger than a predetermined value;
3. The signal processing device for the rotor electrical run-out measuring device according to claim 1, further comprising: The reset command unit commands the integral value of the integrator and the time counter to reset the integral value of the integrator and the measured time of the time counter to zero at the time of resetting. 4. A signal processing device for a rotor electrical run-out measuring device according to claim 3. an eddy current displacement sensor that detects a gap with the rotor to be measured;
A signal processing device according to any one of claims 1 to 4;
a display device for displaying an output from the signal processing device;
A rotor electrical runout measuring device comprising: a detection step of detecting a gap with the rotor to be measured;
an average value calculation step in which the average value calculation unit receives the measured gap signals and outputs an average value;
a subtraction step in which a subtractor subtracts the average value from the gap signal and outputs a difference;
an amplifying step in which an amplifier amplifies the difference;
A rotor electrical run-out measuring method comprising:

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