JPS6219267A - Rotating body device - Google Patents

Abstract

PURPOSE:To substantially instantaneously and surely detect the failure of a rotating body by detecting the failure of the rotating body from the change of motor current and interrupting the outflow from a piping of the rotating body when the failure is detected. CONSTITUTION:This invention relates to a rotating body device in which a current transformer 9 is attached to the mid-way of a power feed cable to a motor and the transformer 9 is connected via a cable 10 to an abnormal current detecting circuit 11 in order to detect the failure of the rotating body 1 from the motor current. An interrupting device 12 such as solenoid valve which is operated by the signal from the AND circuit of the circuit 11 to interrupt the pipeline is provided to the piping 3. Since the failure of the rotating body is substantially instantaneously and surely detected in the above-mentioned manner, the inflow of the powder generated by the failure of the rotating body into the piping is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a rotating body device configured to electrically detect damage to a rotating body contained therein and cut off the flow of piping therein.

[Technical background of the invention and its problems] Generally, when rotating a rotating body at high speed, a material with high tensile strength or specific strength is used for the rotating body, or the rotating body is placed in a container and the surrounding atmosphere is By reducing the windage loss by keeping the rotor in a near-vacuum state, it becomes possible to rotate the rotating body at higher speeds. When the rotating body is rotated, the circumferential speed V of the rotating body is expressed by: g Double force acceleration σ : Tensile strength of the rotating body material γ : Specific weight S[: Safety factor.

FIG. 3 shows a schematic sectional view of a conventional rotating body device having a rotating body of this type. In other words, the upper part is open inside the airtight casing 2! Made of reinforced plastic (hereinafter referred to as F
RP) Especially made of carbon fiber reinforced plastic (hereinafter referred to as CFRP)
) is housed therein, and the lower part of the rotor 1 is rotatably supported by a bearing 6 via a lower shaft 7. This rotating body 1 is composed of a metal motor rotor 4 provided on a lower shaft 7.
It is rotated by a motor consisting of a motor and a motor stator 5 provided below.

Roughly speaking, a plurality of pipes 3 (one pipe in FIG. 3) are inserted from the upper part of the casing 2 through an open opening 8 of the rotating body 1.

This piping 3 is for supplying or discharging gas into the rotating body 1, and is used when this rotating body device is connected in combination with another rotating body device (not shown) installed adjacent to the rotating body device. , and may be used in communication with piping provided in other rotating body devices.

However, when FRP, particularly CFRP, is used as the material for the rotating body 1, dust is generated when the rotating body 1 is damaged. The generated dust then flows through the piping 3 to other rotating body devices and attaches to the bearings of the rotating body 1.
There was a problem that had a negative effect on the rotational performance. In addition, if the dust that has flowed in adheres to the inner surface of the rotating body 1 due to centrifugal force, the balance of the rotating body 1 will be lost, and vibrations will increase during rotation, causing damage, or if the inner diameter of the piping 3 is small, dust may Is there a problem such as clogging pipe 3 and reducing the performance of other rotating body devices? Ta.

[Object of the Invention] An object of the present invention is to provide a rotating body device that does not adversely affect the rotational performance of other rotating bodies when an FRP, especially a CFRP rotating body is damaged.

[Summary of the Invention] A rotating device according to the present invention has an FRP rotating body that rotates at high speed inside an airtight casing.
In addition to detecting damage to the rotating body using the electric current of the motor that drives the unit, a shutoff device is installed that cuts off the flow of piping connecting the rotating body device and other rotating body devices based on this damage detection. This is a characteristic feature.

[Embodiment of the Invention] Hereinafter, an embodiment of a rotating body device according to the present invention will be described with reference to FIGS. 1 and 2. In FIG. 1, the same parts as in FIG. 3 are indicated by the same reference numerals. That is, in FIG. 1 as well, an FRP rotating body 1 having an open opening 8 is housed inside an airtight casing 2.
The lower part of the shaft is rotatably supported by a bearing 6 via a lower shaft 7. The rotating body 1 is rotated by a motor composed of a motor rotor 4 provided on a lower shaft 7 and a motor stator 5 provided below the motor rotor 4. A plurality of pipes 3 (one pipe in FIG. 1) is inserted through the upper part of the casing 2 into the rotating body 1 from an open port 8.

Here, in order to detect damage to the rotating body 1 using the motor current,
A current transformer 9 is attached in the middle of the power supply cable to the motor. This current transformer 9 is connected to an abnormal current detection circuit 11 via a cable 10. As shown in FIG. 2, the abnormal current detection circuit 11 includes a resistor 14 connected to the secondary side of the current transformer 9, a rectifier 15 and a capacitor 16 for smoothing the voltage of the resistor 14, a differential circuit 11, and a Verification circuit 18, AND circuit 1 of both circuits 17 and 18
It has 9. In addition, the abnormal current detection circuit 11 is connected to the pipe 3.
A shutoff device 12, such as a solenoid valve, is provided which operates in response to a signal from an AND circuit 19 to shut off the pipeline. The abnormal current detection circuit 11 and the cutoff bag @12 are connected by an instrumentation control cable 1°.

Next, the operation of the rotating body device according to the present invention will be explained.

Now, if the rotating body 1 is damaged during rotation, the rotating body 1 is F
Due to the unique properties of RP, especially CFRP, it turns into dust, and the lower shaft 7 and motor rotor 4 are made of metal, so although they deform, they do not break into pieces, but in any case, the motor rotor 4
rotation stops.

Therefore, the motor current increases rapidly almost simultaneously with the breakage of the rotating body 1.

In the abnormal current detection circuit 11 shown in FIG.
A resistor 14 converts the detected motor current into a voltage signal, which is smoothed by a rectifier 15 and a capacitor 16. This signal is differentiated by a differentiating circuit 17, and a signal is output when the value exceeds a certain mA.

Here, A is set to a value that slightly exceeds the value during load fluctuation during rated operation.

Further, the smoothed signal is input to the operation confirmation circuit 18. The operation confirmation circuit outputs a signal with a time delay when the input signal exceeds a certain value B. When the current is output from both the differential circuit 17 and the operation confirmation circuit 18, an abnormal current signal is output from the AND circuit 19. That is, when the current suddenly increases while the rotating body is in operation, the abnormal current detection circuit 11 detects damage to the rotating body 1, sends a signal to the shutoff device 12 installed in the pipe 3, activates it, and completes the shutoff of the pipe 3. do. By blocking the piping 3 in this way, the dust generated when the CFRP rotating body is destroyed will not flow into other rotating body devices through the piping 3, and any negative effects on the rotational performance can be easily prevented. It becomes possible to do so.

[Effects of the Invention] Damage to the rotating body is detected by a change in the motor current, and the outflow from the piping of the rotating body is cut off by this damage detection, so that the current change when the rotating body is abnormally damaged is reduced to 1. Since it is within a cycle, it is possible to reliably detect damage to the rotating body almost instantaneously. In addition, since the piping is automatically shut off in the event of damage to the rotating body, dust generated from damage to the rotating body will not flow into the rotating body equipment including other rotating bodies through the piping and have an adverse effect. have a profit.

4.6゜1.4' Fig. 1 is a vertical sectional view schematically showing an embodiment of the rotating body device according to the present invention, and Fig. 2 shows an abnormality'Fi current ratio detection circuit used in the present invention. The internal circuit diagram, FIG. 3, is a schematic sectional view showing a conventional rotating body device.

1...Rotating body, 2...Airtight casing 3
...Piping, 4...Motor rotor 5.
...Motor stator 6...Bearing, 7...Lower shaft 8...
Opening port, 9... Current transformer 10... Instrumentation control cable 11... Abnormal current detection circuit 12... Breaking device 13... Motor power supply cable 14... Resistor, 15... Rectifier 16... Capacitor, 17... Differential circuit 18...
Operation confirmation circuit 19...AND circuit Agent Patent attorney Norihiro Ken Yudo Hiroshi Mitsumata Figure 1 Figure 2

Claims (3)

[Claims] (1) In a rotating body device that has a rotating body made of fiber-reinforced plastic that is rotated at high speed by a motor within an airtight casing, and in which a pipe through which fluid inside the rotating body flows is inserted, the rotating body is driven. A rotating device characterized in that an abnormal current detection circuit is installed to detect damage to the rotating body due to abnormal current of the motor, and a cutoff device is provided in the piping to interrupt the flow in the piping based on a detection signal of the abnormal current detection circuit. body equipment. (2) The rotating body device according to claim 1, wherein the shutoff device is comprised of a solenoid valve that is operated by a detection signal from an abnormal current detection circuit to close the piping. (3) The abnormal current detection circuit includes a current transformer that detects the motor current, a resistor that converts this current signal into voltage, a rectifier that converts AC voltage to DC, a capacitor that smoothes DC ripple, and this DC A differentiating circuit that detects changes in voltage and issues a signal when the amount of change exceeds a certain value, an operation confirmation circuit that issues a signal after a time delay when this DC voltage exceeds a certain value, and a differentiation circuit and an operation confirmation circuit. The rotating body device according to claim 1, further comprising an AND circuit that outputs a rotating body abnormality signal when signals are received from both.