JPS582719A - Balancing device for rotor - Google Patents

Abstract

PURPOSE:To balance a rotor, which is rotated in a high speed in a vacuous vessel, automatically and quickly with high precision without releasing the vacuum state, by irradiating a laser light to the surface of a rotor. CONSTITUTION:The oscillation of a rotor 2 rotating in a vacuous vessel 1 is detected by an oscillation sensor 4, and a phase reference signal is generated by a pulse sensor 5 and is inputted to a pulse shaping equipment 7. The output of the shaping equipment 7 and the output of an amplifier 6 are sent to a computer 9 through a tracking filter 8. In the computer 9, the waveform is analyzed, and the balance is analyzed on the basis of stored influence coefficients, and the number of pulses of laser irradiation and the irradiation phase required for correction are sent to a laser controller 10. The controller 10 sends a trigger pulse signal to a laser oscillator 11 to oscillate a pulse laser light l. This laser light l is condensed onto the surface of the rotor 2 through a condenser lens 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a balancing device for a rotating body rotating at high speed within a vacuum container.

For example, the rotating body (rotor) of a turbo molecular pump
Conventionally, the balancing of a rotor that rotates at high speed in a vacuum container, such as the After that, it was installed in a vacuum container and a rotation test was performed up to the normal rotation speed. If the rotor generates excessive vibration, the vacuum state is released, the rotor is removed from the vacuum container, and the balance is corrected again in the atmosphere.

The balance correction method described above requires a lot of work, such as releasing the vacuum state of the rotor in a vacuum container, disassembling it, dumping it, correcting the balance in the atmosphere, reassembling it, and vacuuming it, and requires a lot of labor. Another disadvantage is that it takes a long time to obtain highly accurate balance.

In other words, rotating the rotor at high speed in the atmosphere requires a large drive torque6 and is dangerous, so a general-purpose balancing machine can only detect imbalances at a rotation speed that is very low compared to the normal rotation speed. . Therefore, it is difficult to detect unbalance with high precision, and it is difficult to control minute amounts in parancing correction cutting by machining.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a balancing device that automatically balances a rotor rotating at high speed in a vacuum container quickly and with high precision without releasing the vacuum state. purpose.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a rotor 2 is supported by bearings 3 within a vacuum vessel 1. As shown in FIG. A vibration sensor 4 and a pulse sensor 5 are arranged near the outer periphery of the rotor 2.

The vibration sensor 4 includes a signal amplifier 6, and the pulse sensor 5 includes:
The signal amplifier 6 and the pulse shaper 7 are respectively coupled to a pulse shaper 7, and the signal amplifier 6 and the pulse shaper 7 are coupled to a tracking filter 8. This tracking filter 8 is
The computer 9 is coupled to a conbeater 9 for calculating the amount of rotor unbalance, and this computer 9 is connected to a laser controller 1.
0, and this controller 10 is connected to a laser oscillator 11 that emits laser light.

A condensing lens 12 is arranged in front of the laser oscillator 11, and a laser transmission window 13 is provided in a vacuum container IK vacuum sealed.
The laser beam t focused through the rotor 2 is configured to be irradiated onto a predetermined position of the rotor 2. Note that a film feeding device 14 is provided between the laser transmission window 13 and the rotor 2 to feed a transparent thin film made of plastic or the like continuously or intermittently.

Next, the operation of the balancing device having the above configuration will be explained.

The vibration of the rotor 2 rotating within the vacuum container 1 is detected by the vibration sensor 4, and a phase reference signal of the rotor 2 is generated by the pulse sensor 5 and input to the pulse shaper 7. The output of this pulse shaper 7 is a rectangular wave with one period per rotation, and this output signal is transmitted to the signal amplifier 6 of the vibration sensor 4.
It is input to the tracking filter 8 together with the output signal of. A bandpass filter is applied to the tracking filter 8 using the pulse signal as a reference signal.

The filtered vibration waveform is sent to the computer 9.

Waveform analysis is performed in this computer 9, and the rotational speed of the rotor 2 and the amplitude and phase of vibration are read.

Therefore, balance analysis is performed based on the influence coefficient stored in advance in the computer 9, that is, the amount of change in vibration amplitude due to one pulse of laser irradiation, and the number of laser irradiation pulses and irradiation phase necessary for balance correction are determined as data. It is sent to the laser controller 10 as a.

The laser controller 10 generates a trigger pulse signal with a time delay corresponding to the irradiation phase instructed by the conbeater 9 based on the output signal of the pulse shaping fi 7, and transmits the trigger pulse signal to the laser oscillator for the required number of irradiations. Send to 11.

The laser oscillator 11 is excited by this trigger pulse signal and oscillates a pulsed laser beam t. This laser beam t is focused onto the surface of the rotor 2 via a condensing lens 12 .

The laser transmission window 13 provided in the vacuum vessel 1 through which the laser beam t passes is preferably made of quartz glass when the wavelength of the laser beam is 1.06 μm, for example.

By the laser beam t focused on the surface of the rotor 2 as described above, the surface metal of the rotor 2 is instantaneously heated, melted, evaporated, and removed by balance.

During the above heating, evaporated metal and molten metal droplets fly from the surface of the rotor 2 and adhere to the inner surface of the laser transmission window 13, reducing the transmittance of the laser beam t. A device 14 is provided. That is, the film feeding device 14 provided between the laser transmission window 13 and the rotor 2 feeds the transparent thin film continuously or intermittently, and when irradiating each laser pulse, the film surface is always kept at a constant KM. The laser beam is transmitted through the diaphragm to prevent the above-mentioned decrease in transmittance.

The drive of this film feeding device 14 is controlled by the computer 9.

As described above, the balancing device of the present invention has the following effects.

(1) Once installed in a vacuum container, evacuated, and rotated, there is no need for manual work such as vacuum breaking, disassembly, reassembly, and vacuuming until the balancing work is completed, and the high speed of the rotor Balancing work can be performed during rotation, reducing the number of man-hours and working time.

(2) The removal amount per unit laser pulse in laser cut balance is as small as about 0.1 mg or less, and therefore extremely accurate balance correction is possible (8) Automatically by computer control, Balancing work can be performed quickly and accurately.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a balancing device showing an embodiment of the present invention. 1...Vacuum container, 2...Rotor, 3...
・Bearing, 4: Vibration sensor, 5: Pulse sensor, 6: Signal amplifier, 7: Pulse shaper, 8: Tracking filter, 9: Computer 10° °° laser controller, 11°°” laser oscillator, 12°°” focusing lens,
13... Laser transmission window, 14... Film feeding device, t... Laser light. Application agent Patent attorney Gobe Kikuchi? reed

Claims (1)

[Claims] A computer that calculates the amount of unbalance of the rotating body by combining detection signals obtained by the device including: a rotating body rotatably provided in a vacuum container; a vibration detection device that detects vibrations of the rotating body; , a rotating device controlled by the computer, comprising a laser oscillation device that oscillates a pulsed laser beam, and a condensing lens that condenses the laser beam and irradiates it onto the surface of the rotating body. body balancing device.