SU1709184A1 - Method of automatic balancing rotor systems - Google Patents

Abstract

The invention (related to the balancing technique and can be used to carry out autobalances at subcritical frequencies. The purpose of the invention is to expand the technological capabilities by reducing the rotor speed of the system during the autobalancing process due to the additional effect on the system by vibration. To implement the method a rotor of a system with a vertically oriented axis coaxially with it, a clip is installed with corrective masses in the form of freely moving cured balls; replicate, rotate at the operating frequency and act on it by an external sinusoidal force, perpendicular to the axis of its rotor, at a frequency equal to or a multiple of half the radial natural frequency of the rotor system, with an amplitude, moving the corrective masses, and for a time necessary to achieve imbalance. Next, the holder with corrective masses is quickly heated by an external electromagnetic field at the melting point of the solder, which has been used to service the inner surface of the holder and tiruyuschih mass "and upon cooling they are fixed in position. 2 or.g. (The invention relates to methods of auto-balancing rotary systems and can be used to balance at subcritical rotational frequencies. The purpose of the invention is to expand the technological capabilities of balancing by reducing the frequency-rotation of the rotor system during balancing. Fig. 1 shows installation diagram that implements the proposed method of automatic balancing of rotor systems; FIG. 2 is a plot of the residual unbalance of the D-electric motor NB-22-23 and the number N of corrective balls s (the mass of the ball is 0.04 g, diameter 1 mm) of the magnitude of the vibration amplitude as measured by the spectrum analyzer measured at the rotational frequency. The unit (figure 1) includes a balanced rotor system 1 with a coaxially fixed yoke 2 on it, which are placed corrective balls 3. The yoke is made in the form of • viоQOSo4 ^

Description

thin-walled gutter with openings Ц and internal surface covered with solder. The installation also includes three channels: vibration, measuring and fixing. The vibration excitation channel consists of a series of sound, frequency, power amplifier 6 and vibration exciter 7 connected in series, on which the rotor system 1 is elastically fixed with the possibility of radial and axial movement, and the axis of the rotor system is perpendicular to the direction of excitation. The measuring channel consists of the after-connecting vibrating transducer 8 mounted on the rotor system housing in the area of Bearing bearings for sensing radial vibration, vibration meter 9 and the spectrum analyzer 10. Fixed channel contains inductor lamp generator 1t with inductor 12.

The automatic balancing of the rotor system is carried out in three stages, of which the first two are preparatory. The first stage: the definition of its own radial frequency. To do this, with a non-rotating rigidly fixed rotor system .1 and when the vibrator 7 is turned on, the generator frequency is automatically or manually tuned and the frequency at which the maximum amplitude is reached is measured using the vibration meter 9 and the spectrum analyzer 10. This frequency is the natural frequency of the rotor system. The second stage: determination of the residual imbalance of the rotor system and the minimum number of balancing balls. With a rigidly fixed rotor system 1 rotating at an operating frequency and an audio frequency generator 5 disconnected, the signal amplitude at the operating rotation frequency is determined from the spectrum analyzer 9. Then, according to the schedule (Fig. 2), which is built according to a known method, the residual imbalance of the rotor system and the minimum number N of balancing balls are found. Directly automatic balancing is performed in the third stage and is as follows. When the rotor system 1 is stopped through the holes in

clip 2 is laid with trimmed balls 3, the number of which is defined as

.

Then, the rotor system is elastically mounted on the vibration exciter 7 so that the self-resonant frequency of fixing the rotor system on the vibration exciter 7 is about half of the previously measured radial frequency of the rotor system. The required mode of rigidity of fastening of the rotor system is determined experimentally for a specific type of rotor system. Then the rotor system is driven into rotation with an operating frequency, and exciter 7 from the audio frequency generator 5 is fed through power amplifier 6 with a frequency equal to or a multiple of half the radial natural frequency of the rotor system. The amplitude and duration of the excitation signal are determined experimentally from the condition that the permissible unbalance of the rotor system is reached. After that, the excitation is turned off and, with a rotating rotary system, the vibration meter 9 and the analyzer 10 record the amplitude at the rotation frequency. A decrease in amplitude to a value characterizing the permissible imbalance, compared with the amplitude measured at the rotational frequency and corresponding to the initial (before balancing) imbalance, indicates compensation of the latter and that the balls are located in the cage in the auto-lancing position. Further, without turning off the rotation of the rotor system 1 and without applying voltage to the vibration exciter 7, inductor 12 of the lamp generator 11 is supplied to the side surface of the sleeve 2. balls 3 to the melting point of the solder, not having time to heat the remaining elements of the rotor system. After the inductor 12 is turned off, the solder solidifies, fixing the balls 3 in a position at which the permissible unbalance is reached. The rotor system is then transferred to the desired operating position.

Example. Balancing was carried out for the MB-22-23 rotor system of the electric motor. On the rotor of the electric motor was mounted a holder in the form of a disk with a toroidal groove inside and a hole for laying the balancing balls. The electric motor case was mounted on the rod with vibration engine Auditor 11076 (GDR, RFT), vibration exciter from a low-frequency generator 03000 (RFT through a LV-103 power amplifier (RFT)). On the electric motor case, a vibrator KD-91 was installed (to control rotor system vibrations in radial direction), the output of which was connected to a series-connected vibration meter 11003 (GDR, VDT company) and a spectrum analyzer. The measured radial frequency of the MB-22-23 rotor system is 20 Hz. engine is 80 Hz; that is, less than the natural frequency of more than 5 ra.

 The amplitude at a rotational frequency of 80 Hz was 80 mV using a spectrum analyzer. The previously constructed dependence of the amplitude of the radial vibration at the frequency of rotation on the magnitude of the unbalance and the number of correction balls for the MB-22-23 electric motor (FIG. 2) determined the residual unbalance (Q, kS T.mm) and the required number (N "12) corrective balls As balls were used objruzhennyy djuriki from the bearing, each with a mass of 0, g and a diameter of 1 mm. Further, the motor was elastically fastened on the exciter so that the axis of rotation occupied a vertical position. 12 balls were laid in the holes of the holder (diameter 40 mm). Then the electric motor was turned into rotation and a vibration signal with a frequency of 210 Hz, amplitude of 12 m / s and length C was given to the vibration exciter.

09184

5 seconds. After removing the voltage from the vibration exciter, the imbalance was monitored at the operating frequency as indicated by the spectrum analyzer. A sharp drop in the signal amplitude to a value corresponding to the permissible / unbalance indicates a balancing of the rotor system. After the signal was applied, the amplitude of the radial vibration at a frequency of rotation of 80 Hz was 10 mV, which corresponds to an imbalance of 0.09 G mm (Fig. 2). This value is

J, 1/5 part of the initial imbalance and characterizes the balance of the rotor system, as by; passport data electric motors MB 22-23 permissible residual imbalance is 0.3 G-mm.

20

According to the results of 11sp || 1th, the proposed method reduces the residual imbalance of the pOTopiHoft system by 5 times at the operating frequency)

25 rotations, which is 5 times lower than the critical. skoy.,

Claims (1)

Invention Formula A method of automatically balancing rotor systems, which means that the axis of the rotor system is oriented vertically, mounted on the rotor coaxially with the corrective masses, rotates the rotor system and fixes the position of the corrective masses after reaching the allowable imbalance, it is different and so that technological expansion (of these possibilities by reducing the frequency of rotation of the rotor system during the auto-balancing process, the system is fixed elastically, rotated at the operating frequency and simultaneously affects This is an external sinusoidal force, perpendicular to the axis of the rotor system at a frequency equal to or a multiple of half its radial natural frequency until the permissible unbalance of the rotor system is reached.