DE1230597B - Automatic unbalance compensation device - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

GOIm

German class: 42 k-33

Number: 1230597

File number: L 44129IX b / 42 k

Filing date: February 14, 1963

Date of laying: December 15, 1966

The invention relates to an automatic unbalance compensation device for a part that can be rotated.

As is known, the center of gravity of rotating parts can in certain cases be in the Relocate the course of the operation, with this relocation proceeding progressively or suddenly and can cause the rotating parts to run unsteadily, which under certain circumstances can be very is harmful. This unpleasant fact comes to the fore, of course, the faster the machine is running. This is how you encounter it, for example, with grinding wheels on grinding machines that wear out irregularly in the course of their work or the irregularly distributed moisture in them close (progressive shift of the center of gravity). One can also consider the case of Cite turbines or compressors where a blade breaks (sudden displacement of the Focus).

Various automatic rapid unbalance compensation devices have now been described which allow such unbalances that change over time or that occur randomly to compensate. The proposed facilities, which have proven to be very effective, equal balancing masses are formed from each other, for example three masses that are (each around maximum 120 °) can move freely in the interior of a ring channel filled with a liquid, which is incorporated concentrically into the rotary shaft and connected to it with a force fit. These Masses, all of which can slide sealingly guided in the interior of the channel, border between three spaces of variable volumes are created by pipe sockets with at least three pressure tapping points which are responsive to pressure changes occurring between the shaft and set a fixed reference organ if the shaft does not move under the effect of an imbalance rotates concentrically with this organ.

These pressures transmitted into the three aforementioned spaces act on the movable compensation masses one to shift them, one in relation to the other, until they remove the imbalance, which helped to create the pressure differences that triggered the control signal.

The compensating devices of this type therefore comprise two essential parts: Movable ones Masses in a circular career (receiving system) and organs for tapping off the pressure which, under the action of a centrifugal force, is a control automatic Imbalance compensation device

Applicant:

Landis Gendron S. A.,

Villeurbanne, Rhone (France)

Representative:

Dipl.-Ing. R. Müller-Borner

and Dipl.-Ing. H. H. Wey, patent attorneys,

Berlin 33, Podbielskiallee 68

Named as inventor:

Paul Favrot, Lyon (France)

Claimed priority:

France of April 20, 1962 (895 197)

signal produces in order to bring about the relocation of these masses (transmission system).
Such unbalance compensators are described in French patent 1,290,875, for example. The invention relates to a device for automatic compensation of the imbalance of a rotor with an annular chamber which is divided into pressure medium spaces of variable volume by means of compensating masses arranged movably in it, the pressure medium supply to each pressure medium space through the play between the shaft and, which varies depending on the imbalance a fixed sleeve is controlled.

In the compensators described so far, the receiver system was designed so that each compensation mass played an equal role, d. That means that all masses (mostly three) had the freedom to themselves to shift under the action of the pressure differences prevailing on their opposite sides. According to the proposed systems, all masses (e.g. spheres) could all be in Move circular chambers that were divided equiangularly and were in communication with each other or in which the movement of the movable masses in the annular channel is only distributed through equiangular Attacks was limited and in this case each of the rooms receiving the pressure signals in the canal itself was bounded by two adjacent masses.

This arrangement, in which all compensation masses are free, appears to be the most desirable

609 747/164

and most satisfactory because it takes care of the symmetry or the initial structural Balancing the apparatus especially account. In fact, however, this arrangement has certain Defects, which are to be pointed out in the following, with the one selected here Case is that of a compensator with three masses, because this case is the most common but the deficiencies remain exactly the same for a larger number of movable masses.

In the event that there is an imbalance, the three masses are distributed irregularly in the channel, and they enclose angles K ₁ , <x ₂ , <x _{3 which} differ from one another by 120 °, so that the resulting center of gravity is on the opposite side of the imbalance falls, which has caused the signal, this operating state can be realized by an infinitely large number of positions of each of the masses. The masses thus assume a fixed position, one with respect to the other, but not with respect to the channel, and their center of gravity is in a stable state of balance without any of the masses being in a stable state of equilibrium. As a result, when the apparatus (for example a grinding wheel) experiences a positive or negative acceleration while rotating, the totality of the three masses shifts as a single part by inertia with respect to the channel, whereby the center of gravity of the three masses shifts equally and a new one Imbalance can appear (created by the balancing apparatus itself). Of course, this imbalance is automatically corrected within more or less short delay times, depending on the response speed of the apparatus, whereby this delay can under certain circumstances last as long as that which was necessary for the initial unbalance compensation. Afterwards, the position of the masses in the new state of equilibrium may be different from the position that was reached after the initial unbalance compensation, but it is reproduced more and more every time the machine changes its pace (e.g. every time the tool comes into contact with the part to be machined) or, less noticeably, over and over again.

In addition, for three masses that result in a center of gravity, that is in a certain point lies, an infinity of relative positions, so that the masses theirs when an imbalance occurs Have to seek position among an infinite number of possibilities, which has the effect of delaying their attitude or of putting them in danger run to move from one position to another.

If the machine is in operation, while the three masses are distributed according to the angles a _v a ₂ , a _{3 in} order to compensate for an imbalance, and if the machine is temporarily stopped, the three masses first swivel out a little (in particular when the channel is filled with oil, which is usually the case), with its center of gravity coming to the lowest point. If at that moment the machine is started up again, the apparatus must first rebalance the imbalance which it has caused to appear. For the pail that the standstill is a longer one, due to the low loss of liquid between the masses and the circular channel, each mass individually enters the lowest point of its movement path. In such a case, where the balancing equilibrium has to be restored when the machine is restarted, which has only happened in a few moments, the compensation is then not ensured.

After all, one of the properties sought in unbalance compensators is their speed of response, and the various proposed signal transmission systems particularly aim at that Receiving the signal with the greatest possible efficiency, d. H. under press and in Quantities as large as possible.

The effectiveness of these signals is very reduced in the previously proposed receiver systems, which is due to the fact that the tightness of the boundaries of the moving masses Spaces is a very conditional one, since one cannot help but between these movable masses and the To leave enough play on the channel.

The invention addresses these various shortcomings and at the same time also offers different ones other advantages, which will be specified in more detail below.

According to the invention, the unbalance compensator is designed in such a way that the ring channel is divided by two movable compensation masses and an immovable compensation mass in three pressure medium spaces is divided.

It is advantageous if the immovable compensation mass is lighter than any of the movable ones Compensation masses and an additional weight compensating for the difference in weight are provided is.

It is also advantageous if the immovable compensation mass consists of an annular chamber there is a radially traversing partition.

These different parts define three zones of variable volume in the canal, namely: a zone between the aforementioned partition and the first movable mass, a second zone between the first and the second movable mass and a third zone between the second movable mass and the septum. In each of these three zones opens a channel system that delivers the control signal to each Pressure tapping is connected, two of the mentioned channel systems in particular in the Near the septum (on both sides of the same) open into the canal, while the third canal system opens out on the radius that passes through the abovementioned stop.

According to a preferred embodiment of the invention, the fixed compensation mass formed by the septum that closes the annular channel and is the weight of said Partition chosen so that it is the same as that of each of the movable compensation masses. ·

The compensation device designed in this way allows unbalances that are just as large as before to compensate for the facilities described, in which all masses were movable and in which the ring channel was not uninterrupted, i.e. in which the pressure medium was completely around the channel could circulate.

In the device according to the invention there is one for each unbalance to be compensated, namely one

always only one position of the two movable masses, and these masses take up once they are have been brought into their compensation position by the control pressures, to each other as well as in fixed positions with respect to the rotating device, these positions being in the stable Are in equilibrium, which remedies the above-mentioned deficiencies.

Of course, the pressure differences in the three zones defined above can appear step and which provide the necessary force to move the two moving masses into their To bring compensation position, by means of any pressure transmission system with by 120 ° tapped taps at a distance from each other, which are in the liquid film of a dynamic Bearing of a static bearing or a bearing with a completely floating bearing of the Shaft or an auxiliary camp, which the latter for its part not at all to the Contributes to storage or guidance of the rotating shaft.

The pressure medium, which the interrupted annular channel of the invention Device fills can be a liquid (e.g. oil) or a gas (e.g. air).

The invention is illustrated in the following detailed description and drawings that move together refer only to one of the possible embodiments of the invention and only one not the invention treat restrictive example, explained in more detail.

F i g. 1 shows in radial section a view of an embodiment of the compensating device according to the invention, wherein the cut is made through the part which encloses the annular channel;

F i g. 2 shows the same device in section along the line H-II in FIG. 1 represents;

F i g. 3 schematically illustrates a radial section along the line ΙΙΙ-ΠΙ of FIG. 2, a Showing pressure signal transmission system capable of supplying the compensator of the invention.

In a part 2, which is positively connected to the shaft 4 to be balanced, an annular channel 6 is machined concentrically to the axis of the shaft 4. A cover 10, which is fastened to the part 2, forms one of the walls of the channel. The cross-section of the channel can be polygonal (as shown) or round, so that the channel represents a torus (in this case the part 2 can be made of two parts symmetrical with respect to a radial plane II). The channel is sealingly interrupted over a restricted circular arc by a closure member or a partition wall 12, the latter also serving as a fixed compensation mass. Furthermore, two mutually identical, movable compensation masses 14 and 16, which have the same weight as the partition 12, are used in the channel.

The movable compensation masses can be formed from within the channel with a small clearance, for example of the order of ² / ioo mm, slidably slidable rolls. In the event that a hollow bead channel is present, small balls are advantageously used as movable compensation masses.

A stop 18, which is diametrically opposite the partition wall, forces each balancing mass to always be in stay the same half of the channel. The masses 14 and 16 thus define three spaces 20, 22 and 24 of variable volumes, which with a pressure medium, such as oil or air, are filled.

Corresponding channel systems 26, 28, 30 open into the three interspaces, which by means of the Corresponding longitudinal lines 32, 34, 36 passing through shaft 4 at three corresponding pressure take-off points 38, 40, 42 are connected, which in

ίο a mutual angular distance on the circumference the shaft are provided.

The channel systems 26, 28, 30 are not distributed over a mutual angular distance of 120 °, so that, which also the position of the balancing weights

Let it be assumed that the spaces or interspaces of variable volumes 20, 22, 24 are always able to receive the pressure signal even in the vicinity of the partition 12.
A system that produces this signal is

ao briefly described below as an example to explain the operation of the compensator. Of course any other system of differential pressure diversion could also be suitable.

Around the shaft 4 is a fixed sleeve 44 arranged, which is located opposite the pressure take-off points 38, 40, 42 and which are not shown May have inner chambers. A pressure medium, such as oil or air, is introduced through a channel system 46 in the space between the fixed sleeve 44 and the shaft 4 is present as it rotates. The bearing 48 of any design may or may not be also not be combined with the sleeve 44.

If an imbalance, which is represented in the figures by a mass 50, appears, the device works as follows: The pressure in the liquid ring at the point between the shaft and the sleeve 44 is larger in the zone which is located on the side of the unbalance, since the shaft is tending has to shift eccentrically so that (in the case of the figure) the pressures on the extraction points 38 and 42 come into effect, are greater than the one that affects the extraction point 40 acts. This results in a greater pressure in the annular channel in zones 20 and 24 than in the Zone 22, which causes the movable masses 14 and 16 to move away from the partition wall until the center of gravity of the three masses 12 (fixed) and 14, 16 (movable) reaches the position in which the Imbalance is compensated. At this moment the shaft 4 revolves concentrically with the sleeve 44, and the tapping points 38, 40, 42 absorb exactly the same pressures that are transferred to the zones 20, 22, 24 be, d. that is, the masses maintain the equilibrium they have assumed (a position of equilibrium which, by the way, is the only one for a certain imbalance).

From what has been said above it is already clear that thanks to the not continuous, but according to the invention interrupted annular channel, the pressure changes occurring in zones 20 or 24 have a positive effect on the compensation masses 14 and 16, as would be the case with pistons that move in a cylinder, the bottom of which is formed by the sealing partition 12. Man in this way achieves a faster response to pressure changes and better sensitivity with weak changes than before.

It can also be seen that in the event of an acceleration of the rotating device, the masses 14 and 16 not carried away under the effect of their indolence and not in relation to that Part 2 can turn as a whole, especially not if the agent used is a liquid because the liquid forms a cushion between the moving masses and the septum. on in this way one prevents the harmful imbalance as a result of the inertia that occurs with expansion joints in which all compensation masses are movable.

The practical experience and the calculation have confirmed the initially surprising result, that if the fixed mass 12 has the same weight as the movable masses 14 and 16, one in all Cases can compensate for exactly the same imbalance as with bodies where all masses are movable, and that due to the fact that the masses 12 and 14 by almost 180 ° instead of a maximum of 120 ° as with the previously proposed devices, even one can compensate for even larger imbalances.

For certain embodiments, it can be advantageous to have a thin and light channel in the channel Provide partition wall 12, which only serves the purpose of closing the channel, with the solid compensation mass is then attached to a suitable point of the rotating part 2. So that the result becomes the same as in the case of the above-described embodiment, it is necessary that the Compensation mass has its center of gravity in the radial plane of symmetry of the septum and that the product of their mass times the distance of their center of gravity from the center is the corresponding Product of a movable mass is equal. Apparently you can get the same result too instead of using an additional mass concentrated in said radial plane by means of a corresponding recess in the opposite radial plane.

Claims (4)

Patent claims: 1. Device for automatic compensation of the unbalance of a rotor with an annular chamber, which can be changed in pressure medium spaces by means of compensating masses arranged movably in it Volume is divided, the pressure medium supply to each pressure medium space through the game between the shaft and a fixed one, which varies as a function of the imbalance Sleeve is controlled, characterized in that the ring channel (6) by two movable compensation masses (14, 16) and an immovable compensation mass is divided into three pressure medium spaces (20, 22, 24). 2. Device according to claim 1, characterized in that the immovable compensation mass is lighter than each of the movable ones Compensation masses (14, 16) and an additional weight that compensates for the difference in weight is provided. 3. Device according to claims 1 and 2, characterized in that the immovable Compensation mass consists of a dividing wall (12) which radially traverses the annular chamber (6). 4. Device according to claims 1, 2 and 3, characterized in that the connecting means consist of three channel systems (26, 28, 30) which are essentially in the annular channel (6) partly opposite the fixed stop (18), partly on both sides of the sealing partition (12) in their proximity open, with the opposite ends of these channel systems at differential pressure taps (38, 40, 42) are connected, which are arranged on the circumference of the shaft (4) are. Considered publications:
British Patent No. 719 422. 1 sheet of drawings 609 7Ψ7 / 164 12.66 © Bundesdruckerei Berlin