RU2516722C1 - Rotor with out-of-balance compensator - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: rotor with out-of-balance compensator comprises an impeller of a turbomachine stage and a compensator of impeller out-of-balance in the form of a balance weight made as a segment with circular outer and inner surfaces and a lock member. At least on one side the rotor is fitted by a recess in the impeller body with annular outer and inner undercuts. An annular collar with slots is provided outside on the impeller end face opposite the outer undercut, an outer ledge - opposite the inner undercut. The segment is installed in the undercuts of the impeller recess by the outer conical and the inner surfaces and is fixed by bending the lock member into the collar slot. The slot axis is in the plane being longitudinal to the impeller axis and at an angle to the latter. In the course of the turbomachine operation the balance weight gets in sliding contact by its conical surface with the conical surface of the outer undercut of the disk recess and is reliably pressed by its end face surface to the end face surface of the impeller by centrifugal forces.

EFFECT: invention allows for the simplification of balancing a rotor, for example, an impeller of a turbomachine stage due to no necessity in dismantling it from the machine for balancing, it also provides for decrease of loads on the rotor bearings and for increase of specific speed of the turbomachine due to improved accuracy and stability of the impeller balancing, increased reliability of fixing a balance weight in the impeller and extended service life of the turbomachine impeller.

6 cl, 6 dwg

Description

The invention relates to balancing equipment in general engineering and, in particular, can be used to balance the rotors of turbomachines.

When the turbomachine is operating, due to the imbalance of the rotating parts, rotor vibrations always occur, which significantly reduce the coefficient of friction and can lead to a shift of the balancing weights from the position chosen when balancing the rotor.

The rotor and balancing weights, among other things, are affected by significant aerodynamic forces from air mixing in the turbomachine.

Different thermal expansions of loads and wheels made of various materials can also lead to a shift in balancing weights.

It has been established that balancing the rotating parts of machines by adding corrective weights makes it possible to reduce the loads on the bearings of the machines and thus increase their service life. This is especially important for high-speed machines and engines, when the discharge / throttle response of the rotor during operation reaches several thousand revolutions per second.

A device is known (ed. Certificate of the USSR No. 200857, F16F 15/32, 04/09/1966) containing a load in the form of a segment with a locking plate installed in the groove of the rotor disk, where the cylindrical protrusion of the plate enters the hole in the shoulder of the rotor disk with radial and circumferential grooves. However, cracks appear in the holes on the shoulder of the disk, which are used for setting the locks and are stress concentrators, after a certain time in the range of high centrifugal forces, temperatures and vibrations, which lead to destruction of the disks and accidents with serious consequences.

Known rotary machine (US patent No. 8 177 487, F01D 25/04, 05/04/2009 and its analogue - RF patent No. 2010 117 015, F01C 1/00, 04/30/2010), containing a rotating part with an annular groove and balancing weight. The groove has a base and inclined lateral sides converging to each other from the base to form an opening.

The balancing weight has a housing with inclined sides and is located in the specified groove with the ability to move in the circumferential direction when the inclined sides of the cargo interact with the inclined sides of the groove. The balancing weight is secured in the groove by threaded stops.

The installation allows you to steplessly balance the rotary machine. However, under the influence of pulsating loads on the rotor and the load, the reliability of fastening the balancing load with threaded stops is insufficient.

The closest known device in technical essence and the achieved result is a wheel unbalance compensation device containing a balancing weight made in the form of a segment and installed in the groove of the rotor disk with radial and circumferential grooves (ed. Certificate of the USSR No. 624130, G01M 1/32, 03/09/1977). The load is made with a collar for securing it in the circumferential groove and with radial protrusions, the dimensions and location of which corresponds to the dimensions and locations of the radial grooves. The invention improves the reliability and service life of the disk. However, with one-sided installation of the load in the groove, when the discharge / throttle response of the rotor during operation reaches several thousand revolutions per second, the reliability of securing the load is significantly reduced.

The proposed invention solves the following problems:

- simplification and cheaper balancing of the rotor;

- reducing the load on the bearings of the rotor of the turbomachine by increasing the accuracy and stability of the wheel balancing;

- improving the reliability of fastening the balancing load in the wheel and the service life of the wheels of the turbomachine.

The tasks are solved in that the rotor with an unbalance compensator contains, for example, a turbomachine stage impeller and a wheel unbalance compensator in the form of a balancing weight. The balancing weight is made in the form of a segment with a locking element. The wheel has, at least on one side of the body, a recess with an annular external undercut, and on the outside opposite the undercut at the wheel end, an annular protrusion with grooves. Moreover, the outer surface segment is installed in the external undercut of the wheel recess and is fixed by bending the locking element into the groove of the protrusion.

In accordance with the invention:

- the outer surface of the segment is made of a conical, coaxial longitudinal axis of the wheel, expanding towards the body of the wheel;

- the inner surface of the segment in the cross section is made toroidal;

- the locking element of the segment is made in the form of a folding tab;

- the recess of the wheel further has an annular inner undercut with an outer collar concentric with the annular external undercut, the segment having an inner surface mounted in the inner undercut of the recess;

- the annular surface of the external and internal undercuts of the recesses of the wheel, respectively, are congruent to the circular external and internal surfaces of the segment;

- grooves are placed outside the outer protrusion of the external undercut of the recess;

- the folding foot is located on the free wall of the segment under the outer annular protrusion of the wheel and is fixed on the latter with the deformation of the foot in the groove.

These essential features provide a solution to the tasks, as:

- the implementation of the outer surface of the segment of the conical, coaxial longitudinal axis of the rotor, expanding towards the body of the wheel, and the location of the segment with the outer surface in the identical external undercut of the wheel provides a reliable additional connection of the segment with the wheel during operation of the turbomachine due to the large friction force arising from the action centrifugal forces. This avoids the displacement of the segment (cargo) during the operation of high-speed turbomachines and thereby prevents their unbalancing, and, consequently, at least expensive unscheduled repairs;

- the manufacture of the inner surface of the segment in the cross-section toroidal and the location of the segment by this surface in the inner undercut of the recess of the wheel eliminates the loss of the segment from the internal undercut of the recess in the stationary state of the turbomachine, which improves the reliability of the balancing load in the wheel, improves the accuracy and stability of the wheel balancing and reduces during operation turbomachines of the load on the rotor bearings;

- the implementation of the locking element of the segment in the form of a folding foot further increases the reliability of fixing the balancing load in the wheel by pressing the folding foot to the groove surface by centrifugal forces arising from the operation of the turbomachine;

- the implementation of the annular surfaces of the external and internal undercuts of the recesses of the wheel, respectively congruent to the circular external and internal surfaces of the segment, improves the accuracy of the load in the wheel and the stability of the wheel balancing;

- placement of grooves from the outside of the outer protrusion of the external undercut of the recess allows access to the installation of balancing weights in the wheel and the fastening of the legs of the weights in the grooves without removing the rotor from the balancing machine;

- the location of the folding foot on the free wall of the segment under the outer annular protrusion of the wheel and fixing it on the protrusion with the deformation of the foot in the groove additionally simplifies and reduces the cost of balancing the rotor without removing it from the balancing machine.

The development of the set of essential features of the invention for particular cases of its implementation is given below.

The location of the axis of each groove in the plane of the longitudinal axis of the wheel at an acute angle to the latter can ensure uniform distribution of the foot during deformation in the groove without loading the segment in the outer and inner undercuts of the wheel.

The surface of each groove can be made in the form of part of a torus, conical or cylindrical surfaces. The shape of the groove is determined by the design and speed of the rotor and ensures smooth deformation of the cargo legs in the groove of the wheel without cracking.

Thus, the objectives of the invention are solved:

- simplified and cheapened balancing of the rotor;

- reduced load on the rotor bearings and increased speed of the turbomachine due to increased accuracy and stability of wheel balancing;

- increased reliability of fastening the balancing load in the wheel and the service life of the wheels of the turbomachine.

The present invention is illustrated by the following detailed description of the design and operation of the rotor of a turbomachine with an unbalance compensator in figures 1-6, where:

figure 1 shows a longitudinal section of a wheel containing a balancing weight installed in the outer and inner undercuts of the recesses of the wheel;

figure 2 - balancing weight in section prior to installation in the wheel;

figure 3 is a view of the balancing load from the side of the folding foot;

figure 4 is a view of the rear side of the wheel with grooves located outside the outer protrusion of the outer and the groove of the inner undercuts;

figure 5 is a cross-section of the load installed in the undercut of the recess of the wheel and fixed from displacement by deformation of the folding tab in the groove of the outer protrusion of the external undercut of the recess of the wheel;

figure 6 is a view of a version of the refinement by weight of the balancing load.

The rotor with an unbalance compensator shown in Fig. 1 contains, for example, an impeller 1 of a turbomachine stage and an unbalance compensator of a wheel in the form of a balancing weight 2. The load 2 (see Figs. 2, 3) is made in the form of a segment with a locking element 3. The wheel 1 has at least one recess 4 in the body with an annular external undercut 5, and on the outside opposite the undercut 5 at the wheel end there is an annular protrusion 6 with grooves 7 (see Fig. 4). Moreover, the segment 2 with the outer surface 8 is installed in the outer undercut 5 of the recess 4 of the wheel 1 and fixed by bending the locking element 3 into the groove 7 of the protrusion 6. The outer surface 8 of the segment 2 is made of a conical, coaxial longitudinal axis of the wheel 1, expanding towards the wheel body. The inner surface 9 of the segment 2 in the cross section is made toroidal. The locking element 3 of segment 2 is made in the form of a folding foot. The recess 4 of the wheel 1 additionally has (see FIGS. 1, 5) an annular inner undercut 10 with an outer collar 11, concentric with the annular external undercut 5. Moreover, the segment 2 with the inner surface 9 is installed in the inner undercut 10 of the recess 4. The annular surfaces of the outer 5 and inner 10 undercuts of the recess 4 of the wheel 1, respectively, are congruent (see Fig. 2) to the external 8 and 9 internal surfaces of the segment 2. The grooves 7 are located (see Fig. 4) from the outside of the outer protrusion 6 of the external undercut 5 of the recess 4. In this case, the folding tab 3 is located on free nk segment 2 under the outer annular protrusion 6 of the wheel 1 and is fixed on the latter with the deformation of the legs 3 into the groove 7. The axis of each groove 7 is located in the plane of the longitudinal axis of the wheel 1 at an angle to the latter (not shown). The surface of each groove 7 can be made in the form of a part of a torus, conical or cylindrical surface, which is determined by the design and speed of the rotor of the turbomachine.

To install the balancing weights (segments) 2 in the undercuts 5 and 10 of the recess 4 on the outer collar 11 of the undercount 10 there is a radial groove 12 (see figure 5).

Loads (segments) 2 are made, for example, by turning rings from materials of different densities, such as aluminum, titanium, steel and other materials, and are cut in width equal to or smaller in width of the groove 12 in the shoulder 11.

The rotor is mounted on a balancing machine. Selected by weight one or more loads 2 (from sets of different densities) through the groove 12 (see Fig. 5) are installed in the annular recess 4 of the wheel 1 formed by the annular external 5 and internal 10 undercuts and moved in the circumferential direction to the place defined on balancing machine before setting the load 2. Then the foot 3 of the load 2 is partially deformed with fixing in the groove 7 of the protrusion 6 (see figure 4) with the ability, if necessary, to adjust the mass of the load 2 and its angular location.

After reaching the required value of the impeller imbalance, the foot 3 is finally deformed to contact with the surface of the groove 7 in the annular protrusion 6.

If it is impossible to select the load 2 of the required mass, it is possible to install on the wheel 1 two diametrically different loads of a different mass with a difference in mass equal to the necessary, for example, aluminum, titanium or steel cargo 2. In addition, the necessary mass of the load 2 can be obtained due to its refinement removing excess material, for example, as shown in Fig.6.

The selection of the necessary load 2 is performed without removing the rotor from the balancing machine.

During the operation of the turbomachine, the load 2 with its conical outer surface 8 is in contact with the conical surface of the external undercut 5 of the recess 4 of the disk 1 and reliably pressed by centrifugal forces with its congruent surfaces to the surfaces of the recess 4 of the wheel 1. This, together with the fixation of the load 2, deformation of the foot 3 into the groove 7, when the centrifugal forces are applied to the foot 3, it allows to securely fasten the balancing weight 2 on the wheel 1 in the circumferential direction when dumping / throttle response of the rotor during operation as a part of, for example Example, a high-speed aircraft engine, where the discharge / throttle reach several thousand revolutions per second.

Claims (6)

1. A rotor with an unbalance compensator, comprising, for example, an impeller of a turbomachine stage and an unbalance compensator of a wheel in the form of a balancing weight made in the form of a segment with a locking element, where the wheel has a recess with annular external undercut on at least one side of the body and outside, opposite the undercut at the end of the wheel, an annular protrusion with grooves, and the segment with the outer surface installed in the outer undercut of the recess of the wheel and fixed by bending the locking element into the groove of the protrusion, characterized in that the outer surface of the segment is made of a conical, coaxial longitudinal axis of the wheel, expanding towards the wheel body, the inner surface of the segment in the cross section is made toroidal, and the locking element of the segment is made in the form of a folding foot, the recess of the wheel additionally has an annular inner undercut with an outer collar, concentric annular external undercut, wherein the segment with the inner surface is installed in the internal undercut of the recess, the annular surfaces of the external and internal undercut the recess of the wheel, respectively, congruent with the outer and inner surfaces of the segment, the grooves are located outside the outer protrusion of the external undercut of the recess, while the folding tab is located on the free wall of the segment under the outer annular protrusion of the wheel and fixed on the latter with the deformation of the foot in the groove. 2. The rotor balancing device according to claim 1, characterized in that the axis of each groove is located in the plane of the longitudinal axis of the wheel. 3. The rotor balancing device according to claim 2, characterized in that the axis of each groove is located at an acute angle to the longitudinal axis of the wheel. 4. The rotor balancing device according to claim 1, characterized in that the surface of each groove is made as a part of the torus surface. 5. The rotor balancing device according to claim 1, characterized in that the surface of each groove is made as a part of a conical surface. 6. The rotor balancing device according to claim 1, characterized in that the surface of each radial groove is made as part of a cylindrical surface.

Images