JP2021162498A - Signal processing device of rotor electric runout measuring device, rotor electric runout measuring device, and rotor electric runout measuring method - Google Patents

Abstract

To provide a signal processing device of rotor electric runout measuring device capable of simplifying the run-out measurement of the rotor shaft and reducing the time therefor.SOLUTION: The signal processing device 100 includes: an average value calculation unit 120 that receives a measured gap signal and outputs an average value; a subtractor 130 that subtracts the average value from the gap signal and outputs the difference; and an amplifier 140 that amplifies the difference. The average value calculation unit includes: an integrator that accepts the measured gap signal and outputs an integral value; an integrator that accepts the measured gap signal and outputs the integral value; a time counter that counts and outputs the measurement time; and a divider 124 that accepts the integral and measurement time and outputs the result of dividing the integrated value by the measurement time as the average value.SELECTED DRAWING: Figure 2

Description

The present invention relates to a signal processing device of a rotor electric runout measuring device, a rotor electric runout measuring device using the signal processing device, and a rotor electric runout measuring method.

Vibration measurement of the rotor by a non-contact sensor is used for monitoring the state of an electric motor, a generator, or the like during operation (see Patent Document 1). The vibration value is represented by the displacement (μmP−P) of the portion irradiated with the sensor. In vibration measurement using a non-contact sensor, the permissible value differs depending on the standard, but it is required to minimize the electrical runout of the rotor. After assembling the rotor (completed state), it is difficult to repair the electrical runout, so the electrical runout is inspected in the rotor manufacturing process.
Rotor electrical runout is the difference between the output voltage according to the distance that should be originally obtained and the output voltage that fluctuates due to the material, surface structure, and unevenness of the rotor. In addition, the vibration value changes according to the rotation speed, mainly due to the static or dynamic imbalance of the rotor. On the other hand, the electric runout of the rotor is a property of each rotor and does not change according to the rotation speed.

Special Fair 7-11825

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

Here, the degree of voltage change due to the unevenness of the surface of the rotor or the surface structure is extremely small as compared with the distance between the target rotor and the eddy current type displacement meter (initial GAP voltage). Therefore, sufficient accuracy cannot be ensured by simply reading the change in the distance between the rotor and the eddy current displacement meter.

Therefore, for example, the output of the eddy current displacement meter is biased with a negative DC component, the difference signal is amplified and displayed, and the bias is manually adjusted while observing the display.

FIG. 8 is a flow diagram showing a conventional example of the rotor shaft runout measurement method. An example of a conventional measurement method using a measuring device is as follows.

First, in the measuring device, the eddy current displacement meter detects the 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 reduces the bias value from the distance signal detected by the eddy current displacement meter (step S03). By reducing the bias value, the fluctuation remains mainly.

Next, the measurer adjusts the gain (step S04). In the gain adjustment, it is expected that the gain will be large enough to be sufficiently confirmed on the screen. For example, while confirming this state on a display unit such as an oscilloscope (step S05), the measurer can adjust the gain. It is determined whether or not the gain adjustment is necessary (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 has a large DC component, and the fluctuation component cannot be sufficiently expanded. In this way, the measurer determines whether or not the bias value is appropriate (step S07).

If the measurer cannot determine that the bias value is appropriate (step S07 NO), the measurer repeats steps S02 to S07.

The above is a procedure to be performed in the case of a measurement point of a certain diameter. The measurer needs to repeat the above procedure every time the diameter of the object to be measured changes. Conventionally, when the runout measurement of the rotor shaft using the eddy current type displacement meter is performed, the initial adjustment of the cut of the DC voltage component, that is, the subtraction adjustment of the bias value is manually performed, which is troublesome. I needed it.
Therefore, an object of the present invention is to simplify the run-out measurement of the rotor shaft and shorten the time.

In order to achieve the above object, the signal processing apparatus according to the present invention has an average value calculation unit that accepts a measured gap signal and outputs an average value, and outputs a difference by subtracting the average value from the gap signal. It includes a subtractor and an amplifier that amplifies the difference, and the average value calculation unit includes an integrator that receives the measured gap signal and outputs an integrator, and a time counter that counts and outputs the measurement time. It is characterized by having an integrator that accepts the integrator and the measurement time and outputs the result of dividing the integrator by the measurement time as an average value.

Further, the rotor electrical runout measuring device according to the present invention displays an eddy current type displacement meter for detecting a gap with a rotor to be measured, the above-mentioned signal processing device, and an output from the signal processing device. It is characterized in that it is provided with a display device.

Further, the rotor electrical runout measuring method according to the present invention includes a detection step of detecting a gap with the rotor to be measured, and an average value calculation unit that accepts the measured gap signal and outputs an average value. It is characterized by having a value calculation step, a subtraction step in which the subtractor subtracts the average value from the gap signal and outputs a difference, and an amplification step in which the amplifier amplifies the difference.

According to the present invention, it is possible to simplify the run-out measurement of the rotor shaft and shorten the time.

It is a conceptual diagram which shows the structure of the rotor electric runout measuring apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the signal processing circuit of the rotor electric runout measuring apparatus which concerns on 1st Embodiment. It is a flow figure which shows the procedure of the rotor electric runout measurement method which concerns on 1st Embodiment. It is a 1st screen for demonstrating the effect of the rotor electric runout measuring apparatus which concerns on 1st Embodiment. It is a 2nd screen for demonstrating the effect of the rotor electric runout measuring apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the signal processing circuit of the rotor electric runout measuring apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the signal processing circuit of the rotor electric runout measuring apparatus which concerns on 3rd Embodiment. It is a flow figure which shows the conventional example of the rotor electric runout measurement method.

Hereinafter, the signal processing device, the rotor electric runout measuring device, and the rotor electric runout measuring method of the rotor electric runout measuring device of the rotary electric machine according to the embodiment of the present invention will be described with reference to the drawings. Here, parts that are the same as or similar to each other are designated by a common reference numeral, and redundant description will be omitted.

[First Embodiment]
FIG. 1 is a conceptual diagram showing the configuration of the rotor electrical runout measuring device 10 according to the first embodiment. FIG. 1 also shows the arrangement relationship between the measurement target 1 and the rotor electrical runout measuring device 10.

The rotor, which is the measurement target 1, is a rotating body having a plurality of diameters in the axial direction and having the rotation axis C as the rotation center. One end of the measurement target 1 in the axial direction is supported by the support portion 3, and the multi-end is rotatably supported by the rotary drive unit 2.

The rotor electric runout measuring device 10 includes an eddy current type displacement meter 11, a display device 12, a moving drive unit 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 by rotating the rotor, which is the measurement target 1, and visually checks the voltage swing width on the display device. Make it possible.

The eddy current displacement meter 11 measures the gap between the measurement target 1 and the distance D between itself and the measurement target 1.

The rail 16 is arranged parallel to the rotation axis C of the measurement target 1. The mobile drive unit 15 supports the eddy current type displacement meter 11. The moving drive unit 15 is mounted on the rail 16 and moves on the rail 16. As a result, the eddy current displacement meter 11 can measure the gap along the measurement target 1.

The gap signal measured by the eddy current displacement meter 11 is output to the signal processing device 100. The signal processing device 100 processes the received gap signal, outputs the result to the display unit 12, and displays the result on the display unit 12.

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

The signal processing device 100 includes a receiving unit 110, an average value calculation unit 120, a subtractor 130, and an amplifier 140.

The receiving unit 110 receives the gap signal measured by the eddy current displacement meter 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, an analog signal is converted into a digital signal.

The receiving unit 110 outputs the converted result to the average value calculation unit 120 and the subtractor 130.

The average value calculation unit 120 receives the output of the reception unit 110 and calculates the average value.

The subtractor 130 receives the output of the receiving unit 110 and the output of the average value calculation unit 120, and subtracts the average value, which is the output of the average value calculation unit 120, from the output of the receiving unit 110 to calculate the difference signal.

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

The average value calculation unit 120 includes an integrator 121, a time counter 123, and a divider 124. The integrator 121 receives the output of the receiver 110 and performs an integral operation. The time counter 123 counts the time while the integrator 121 is accepting the output of the receiver 110. The divider 124 receives the output of the integrator 121 and the output of the time counter 123, and divides the integrated value, which is the output of the integrator 121, by the time count value, which is the output of the time counter 123, to calculate the 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 meter 11 detects the gap signal (step S01).

Next, the average value calculation unit 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 effect of the rotor electrical runout measuring device according to the first embodiment. The first screen is a case where the rotor electrical runout measuring device according to the first embodiment is not used. That is, it shows a 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, the fluctuation component cannot be sufficiently confirmed even if the gain is increased within the range that can be confirmed on the display unit. That is, the variable voltage (AC component) cannot be extracted unless the GAP voltage (DC component) is reduced due to the limitation of the dynamic range of the display unit, for example, the memory high coder.

FIG. 5 is a second screen for explaining the effect of the rotor electrical runout measuring device 10 according to the first embodiment. The first screen is the case of the rotor electric runout measuring device 10 according to the first embodiment. That is, the case where the average value is subtracted from the gap signal is shown. In this case, since the difference signal is only the fluctuation amount, the display unit can display the result in which only the fluctuation amount is sufficiently enlarged.

As described above, according to the rotor electrical runout measuring device 10 according to the present embodiment, the runout measurement of the rotor shaft can be automatically performed and high accuracy can be ensured, which simplifies the measurement. The time can be shortened.

[Second Embodiment]
FIG. 6 is a block diagram showing a configuration of a 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 calculation unit 120a of the signal processing device 100a is different from that of the average value calculation unit 120 in the first embodiment. In other respects, it is similar to the first embodiment.

The average value calculation unit 120a in the present embodiment includes 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 capacitance of the capacitor of the first integrator 121a is smaller than the capacitance 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 the two, and outputs the output received from the selected side. At the time of switching, both outputs are bumpless, that is, when one is in use, the other output follows and the output can be switched without fluctuation.

The divider 124 divides the output from the selector 122 by the time count value from the 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 start of the integration operation of the integrator 121, the average value is initially calculated based on the integration value by the first integrator 121a having a short integration time. Then, when the target value is approached, the average value is calculated based on the integrated value by the second integrator 121b whose integration time is longer than this. As a result, it is possible to shorten the time until the average value is calculated at the start of the calculation of the average value.

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 can be as follows.

That is, since the time required for integration to calculate the average value is proportional to the change width when changing from the previous gap D to the new gap D, the receiving unit 110 calculates this change width, for example, the standard. The timing can be appropriately switched by calculating the timing based on the known integration time with respect to 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, the time can be further shortened.

[Third Embodiment]
FIG. 7 is a block diagram showing a configuration of a 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 is different from the second embodiment in that the signal processing device 100b has a reset unit 150, and is the same as the second embodiment except that the average value calculation unit 120a is included. be.

The reset unit 150 includes a difference determination unit 151 and a reset instruction unit 152.

The difference determination unit 151 determines whether or not the absolute value of the output of the subtractor 130 is larger than the predetermined value ε, and if it is determined that the absolute value is larger than the predetermined value ε, the logical value “YES” is set and the predetermined value ε is determined. If it is determined that the value is not greater than the value ε, the logical value "NO" is output.

When the difference determination unit 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. The reset command unit 152 outputs a reset signal to the integrator 121 (first integrator 121a and second integrator 121b) and the time counter 123.

When the integrator 121 and the time counter 123 receive the reset signal, the integrator 121 and the time counter 123 once reset the output value to zero.

According to the signal processing device 100b according to the present embodiment configured in this way, even when the diameter changes in the axial direction, the measurement can be continuously continued, and the time can be significantly shortened.

[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 calculation unit is the same as that of the second embodiment, but the configuration may be the same as that of the average value calculation unit in the first embodiment.

Moreover, you may combine the features of each embodiment. In addition, the embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention.

The embodiments and modifications thereof are included in the scope and the gist of the invention as well as the invention described in the claims and the equivalent scope thereof.

1 ... Measurement target, 2 ... Rotation drive unit, 3 ... Support unit, 10 ... Rotor electrical runout measuring device, 11 ... Turbine current type displacement meter, 12 ... Display device, 15 ... Moving drive unit, 16 ... Rail, 100 ... signal processing device, 110 ... receiver, 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 judgment unit, 152 ... reset indicator unit

Claims (6)

An average value calculation unit that accepts the measured gap signal and outputs the average value,
A subtractor that subtracts the average value from the gap signal and outputs the difference,
An amplifier that amplifies the difference and
Equipped with
The average value calculation unit is
An integrator that accepts the measured gap signal and outputs an integral value,
A time counter that counts and outputs the measurement time,
A divider that accepts the integral value and the measurement time and outputs the result of dividing the integral value by the measurement time as an average value.
A signal processing device for a rotor electrical runout measuring device, which comprises. The integrator has a first integrator having a short integration time and a second integrator having a long integration time.
The average value calculation unit further includes a selector that switches from the integration by the first integrator to the integration by the second integrator and outputs the integrated value to the divider.
The signal processing device for the rotor electrical runout measuring device according to claim 1. A difference determination unit that accepts the difference from the subtractor and determines whether or not it is larger 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.
The signal processing device of the rotor electrical runout measuring device according to claim 1 or 2, further comprising. At the time of the reset, the reset command unit commands the integrator and the time counter to reset the integrator and the measurement time of the time counter to zero. The signal processing device of the rotor electrical runout measuring device according to claim 3. An eddy current displacement meter that detects the gap with the rotor to be measured,
The signal processing device according to any one of claims 1 to 4.
A display device that displays the output from the signal processing device, and
A rotor electrical runout measuring device comprising. A detection step that detects the gap with the rotor to be measured, and
The average value calculation step that the average value calculation unit accepts the measured gap signal and outputs the average value,
A subtraction step in which the subtractor subtracts the average value from the gap signal and outputs a difference.
An amplification step in which the amplifier amplifies the difference,
A method for measuring electric runout of a rotor, which comprises.

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