SU386300A1 - METHOD OF ROTOR EQUALIZATION - Google Patents

Description

one

The invention relates to general engineering, in particular to methods of balancing rotors.

There is a known method of balancing rotors, which consists in determining the magnitude and angular coordinate of the unbalance of the rotor as a rigid body on a balancing machine and set the balance on it, and its weights.

However, it is difficult in a known manner to obtain a high quality balance of the rotors, working at a speed at which their flexibility is manifested.

According to the proposed method, the values and directions of mixing, the main central axis of inertia of the rotor relative to the axis of rotation in the planes of the centers of mass of individual sections of the rotor are determined using the found values of the magnitude and angular coordinate of the imbalance dipers in one of the known methods. balancing loads that compensate for these displacements.

This improves the quality of equilibrium of the rotors operating at the speed at which their flexibility is manifested.

FIG. 1 shows a diagram of the relative position of the rotation axis and the main central axis of inertia of the rotor, where

P is the plane of the main vector; M is the plane of the main moment; OH — axis of rotation; - main central axis of inertia

rotor;

OIP-OIP and OIM-OIM-projection 0 | -O on the plane P and M; and the angle between О-О and - OIM, Vog - the displacement of the center of the t-th mass of the rotor from the axis of rotation;

sOii is the offset of the center of the t-th mass of the rotor

from the main central axis of inertia of the rotor;

eoOii is the distance between the OS axes and

GI-Oi in a plane passing through the center

i and mass perpendicular to 0-0 axis;

eoj is the displacement of the center of the t-th mass of the rotor from the main central axis of inertia when it coincides with the axis of rotation; c is the center of the t-th mass of poTOipa; P is the angle between the axis, gi eo, iНа of fig. Figure 2 depicts a vector diagram explaining the proposed method, where RI and RU are the balancing force vectors in the casting planes I and II;

RNM — coordinate axes that are traces of the planes P and M on a plane perpendicular to the axis of rotation;

el ... ek displacement of the centers of mass of the rotor from the neutral field: 3 BMI and ep are the projections of the vectors ei-vc on the coordinate axes. The theoretical basis of the proposed method follows from the analysis of the equations of a balanced rotor. 5 Yao. +., (1) MOI + MI + MU O, where Sj ° ob is the sum of the centrifugal forces and their moments relative to the center of mass of the rotor; Ri, Rii and MI, Mil are the balancing forces in the casting planes I and II and their moments15 relative to the center of mass of the rotor. It is easy enough to prove that P is EP SP 01-00.1-g Oii, () jyj fj MQ; where Po, t MO, I is the centrifugal force caused by the displacement of the center of the i-th mass from the O-to-Oi axis and its moment relative to the center of the rotor maeza; PoOii and M00.1 - Centrifugal force caused by the displacement of the axis Oi-Oi from the axis O - O and the moment relative to the center of mass of the rotor. Indeed, from FIG. 1 it can be seen that JQ yoh yo oo, 1 + 7o, 1, (3) Since, for real rotors, it does not exceed a few minutes and, then we can assume: eo, i - o, i. Since, 35 then taking into account (3) it is possible to obtain, i -} + Poii, as is known Po, 1 0, MO, I O, (4) The location of the rotor mass eccentricities near the axis is neutral. With accountancy (4) and (2), dependence (1) takes the form of SPoo. + 1 + and O, 45 I, MOO, (5) i.e., the rotor's disbalance as a solid | arises as a result of the displacement of the axis - ",, ,, l ,," l. O from the GI axis -Oi. Consequently, it is necessary to equilibrate in the plane of each disk the centrifugal forces caused by this particular displacement. Such a decision allows the optimal (neutral) system of internal forces and moments on the rotor to be maintained. One of the possible graph-analytical solutions for dependence (5) is as follows. The main vector P and the main moment M of the centrifugal forces acting on the rotor are represented as: Р spoQ z - (1 -f- i), M Moo, 1 - (L11 + Mi} -65 4 If the plane of the I transform b, and the plane of reduction II at a distance a from the center of mass of the rotor, then i-b ij - Ru-a .b + Rna) a (A coordinate system is built with the axes P and M (Fig. 2), taking the positive direction of the vector Rp Ri Rn and RM Ru - Ri. These axes are the traces of the planes of the main vector and the main moment on the plane drawn through the center of mass of the rotor perpendicular to the axis of rotation. In this coordinate system, the position of the main central axis of inertia of the rotor is determined. The projections eoo, / on the P and M axes are denoted as Kor. In the RO plane, (6) since the OIP-Oip and Oj-Oj axes are parallel. the theorem on the addition of parallel forces (- m, w (7) where gps is the mass of the rotor, it is the displacement of its center relative to the axis of rotation. After the stand (7) in (6): "-," of in the M plane (Fig. 1) the magnitude of Vmg is found from the equation of moments E / n and i MI i and the geometric dependence e // tg a, Where / r is the distance from the center of mass of the rotor to e 00.1, then 7 С9 ЛИ99 -, l2V / о / The dependences (8) and (9) allow to find eoo, i, - the position of the main central axis of the rotor inertia relative to the axis of rotation. Accepting j P P MI MI builds the vectors necessary for balancing: ei.e The practical implementation of the proposed method is the following sequence: 5: 1. For the rotor, the balancing masses mi and mc in the cast planes I and II are known by way. 2.Stroi vector diagram from RI, Cr: / TZji r, j, Rp Ri,, I A., where / -I and Hz are the radii of the mi and ti. 3. Calculate the values of RP - R ,, - a-li ep -, e where OTC is the mass of the rotor, 1 and 4 are the distances from the center of mass of the first and last disks to the center of mass of the rotor. 4. Lay on the vector diagram in a certain scale: ep - in the direction of Rp. fVi - in the direction of the projection fi on the axis M, emp - in the direction of the projection Rn on the axis M and build: ei,., e -g + e 5. The ends of the vectors ej and ek are connected straight and divided into k parts, proportional to the distance between the centers of mass of the rotor disks. Connecting the straight segments with the beginning of 5 10 .. 20 25 30 35 coordinates, get all the desired K vectors. 6. Calculate the balancing masses niyi (i, 2, ... k) for the installation of balancing weights: myt where Gog is the radius of installation of the balancing weights. 7. Install balancing loads with a mass of niyi on the rotor. The installation location is determined by the angle ((er, RI) or y (er, RII) in the vector diagram. Subject of the Invention The method of balancing the rotors, which consists in determining the magnitude and angular coordinate of the unbalance of the rotor as a rigid body on the balancing machine and set to the rotor, balancing weights, characterized in that, in order to improve the quality of balance of the rotors operating at a speed at which their flexibility is manifested, by one of the obtained values of the magnitude and angular coordinate of the imbalance stnyh methods of determining the magnitude and direction of displacement of the central main inertia axis relative to the axis of rotation in planes individual centers of mass of the rotor portions and set in these planes balancing loads, these compensating offset.

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