RU2068990C1 - Device registering deviation of rotation axis of object - Google Patents

Abstract

FIELD: measurement technology. SUBSTANCE: device is related specifically to active balancing measurement means, in particular to aerostatic bearings. Device has case rotor with bearing cylindrical and flat surfaces floating bushing with outer spherical surface placed between case and rotor and forming aerostatic bearing together with spherical surface of rotor , passages to feed working medium under pressure into working gaps of sliding planes, insert rigidly embraced by hemispherical segments of rotor, rotor state pickup incorporating radiation source, beam splitter, forming optics, reflectors, matrixes of photodetectors and registration circuit composed of amplifiers, analog-to-digital converter, flip-flops, counters, threshold elements, logic AND and OR gates and compensating mass. Device is additionally inserted with second beam splitter and four corner reflectors. One of hemispherical segments of rotor and insert are made optically transparent. Insert is manufactured in the form of wedge disc with input annular diaphragm on one of butts and total internal reflection. Output cylindrical surface of optical wedge disc is provided with antireflection coating. Central part of floating bushing is provided with reflecting belt with Fourier spectrum built into it. Beam splitters of input ray are mounted on rotation axis with turn of their beam splitting surface through 90 deg. Second and third microlenses of forming optics with matrixes of photodetectors are mounted in orthogonal planes. EFFECT: improved functional efficiency. 13 dwg

Description

 The invention relates to active measuring means for balancing dynamic objects, in particular aerostatic sliding supports, used as technical means for providing optical recording (reproduction).

 The quality of balancing a dynamic object determines the accuracy of the position of its axis of rotation, which during optical recording is determined by the value of the radial beats of the recording object less than a tenth of a micrometer and small angles of the end beats. The need for this is determined by the fact that a bit of optical information occupies a site of less than one micrometer and, the less beats, the better the recording quality. The requirements for minimum deviations of the axis of rotation are tightened in the manufacture of kinoform elements (corrective elements of nonlinear optics). Balancing a dynamic object to certain values of the deviations of the axis of rotation makes it possible to compact the optical record. Aerostatic sliding supports are traditionally balanced due to spatial adjustment of the position of the compensation masses, and stationary meters not usually built into the sliding support, which are several times larger than the sliding support itself, are used as meters (recorders) of deviations of the rotation axis. Combining the balancing recorder with a sliding support makes it possible to measure during operation and to certify the manufactured product. Malfunctions during operation are a very common occurrence, as this is due to vibration of the base.

 Known rotation support according to the application N 4256361/27 (priority 3.06.87) contains a movable and fixed elements, mating on two sliding surfaces, one of which is spherical and the other flat, while in the fixed element there are channels for supplying compressed air to the mating sliding surfaces from a pressure source, in it the movable element is made in the form of a disk with a central hole of a spherical shape and forms an integral connection with the fixed element, and the center of the spherical surface is located on the side s opposite flat surface of the movable member.

 To ensure the accuracy of the position of the axis of rotation of this support, spatial balancing of its movable element is necessary.

 Close in technical essence is a device for balancing rotors in its own bearings by combining the axis of inertia of the rotor with the axis of rotation (see ed. St. USSR N 1232971, class G 01 M 1/38), containing a pin having a surface articulated with a clearance and on the equidistant surface of the rotor shaft connected to the journal through an elastic element with a Central hole. When the rotor rotates at a supercritical speed, the rotor self-centers on removable elastic elements. The axis of inertia of the rotor is combined with the axis of rotation, after which fixation is carried out by means of a hardening mass poured into the cavity, for example, epoxy resin.

 Known aerostatic sliding support (see application N 4769811/27, priority 30.10.89, class F 16 C 32/06), comprising a housing with two supporting spherical surfaces and a rotor with a rigidly fixed sphere at its end, forming with one of the spherical supporting surfaces spherical aerostatic bearing, as well as a floating sleeve located between the housing and the rotor with an external spherical surface, forming with the supporting spherical surface of the rotor a second aerostatic bearing and channels for supplying a working medium under pressure to the slave bearing clearances. In order to increase the stability of the axis of rotation, this support is equipped with a radially floating annular insert with a spherical inner surface located between the spherical surfaces of the housing and the floating sleeve with the possibility of its coverage from one of its ends, as well as an electromagnetic centering system along the axis of rotation.

 To ensure the stability of the axis of rotation in this rotation support in this sliding support, precise spatial balancing is necessary.

The closest to use common elements and circuit features is a device according to ed. St. USSR N 901874, class G 01 M 11/00, comprising a light source, a holder for the lens frame, a beam splitter, an array of photodetectors, a position sensor for the holder for the lens, the actuators and a control circuit including a generator connected to a difference comparison and isolation unit, a photovoltaic converter unit, outputs through which the difference comparing unit connected to the synchronizer, it photodetectors matrix is in the form of three sectors by 120 ^o from one of the photodetectors, placed at overlapping sectors, a control circuit in the Introduction There are two JK triggers with a control unit and two pulse width to current pulse converters, with one of the inputs of the JK triggers control unit connected to the output of the photoelectric converter unit, and the other to the output of the difference comparison and separation unit, two outputs of the JK- control unit flip-flops are connected to the inputs of each of the JK-flip-flops, in addition, one of the outputs of the control unit of the JK-flip-flops is connected to the input of the comparison unit and the selection of the difference, and the output of the synchronizer is connected to the inputs of each of the conversion blocks Ia pulse duration current pulse.

 This device provides for the use of a rotation spindle, which is equipped with electromagnetic systems for fixing the ball segment and the holder of the frame with a lens. Centering the part according to the components of the eccentricity sample and the tangential component is provided by electromagnetic vibration transducers.

 The disadvantages of the device include the lack of reliability of the current collectors that provide power to electromagnetic systems on a rotating rotor. In addition, current collectors introduce disturbances that reduce centering accuracy, which makes them unacceptable for aerostatic spindles.

 The purpose of the invention: to increase the sensitivity of the device and expand its functionality.

This goal is achieved by the fact that in the device for recording the balancing of the sliding support, comprising a housing with a cylindrical and flat surfaces, and also located between the housing and the rotor, a floating sleeve with an external spherical surface, forming an aerostatic bearing with the spherical surface of the rotor, channels for supplying a working medium under pressure in the working gaps of the sliding planes, a liner rigidly covered by hemispherical segments of the rotor, a sensor consisting of a rotor, including a source of radiation, a beam splitter, forming optics, reflectors, photodetector arrays and a registration circuit as a part of amplifiers, an analog-to-digital converter, triggers, counters, threshold elements, coincidence logical elements and OR, and compensation masses, an additional second beam splitter and four corner reflectors are introduced into it, and one of the hemispherical rotor segments and the liner are optically transparent, while the liner is made in the form of a wedge disk with an input annular diaphragm and with full internal reflection And the output cylindrical surface of the disc is provided with a reflective coating, and melts the sleeve in the central part is provided with a reflective belt with built therein Fourier spectrometer, wherein the beam splitters of the input beam are mounted on the rotation axis with the turn of the beam splitter surface 90 ^o, and the second and third the micro-lenses of the forming optics with the photodetector arrays are mounted in orthogonal planes and form the optical levers of the end beats of the rotor with the corresponding reflectors, and the scheme the recording was performed in three channels, and an extremum shaper was additionally introduced into each channel, while in each channel the photoconverting elements with amplifiers are connected to an analog-to-digital converter connected to the extremum shaper connected by signal outputs to the inputs of the OR element, and the synchronization output to the counter zeroing input clock connected to the output of the OR element, and outputs with the control inputs of the multiplexer "1 to n" connected to the bus log. 1 and to the first inputs of the block of RS-flip-flops, the second inputs of the display resolution combined with the first input of the RS-flip-flop and with the output of the reference mark sensor; the outputs of the RS-flip-flop unit are connected to the inputs of the display unit, the control input connected to the output of the RS-flip-flop of the resolution of indication, the second input combined with the output of the OR circuit.

In FIG. 1 shows a General view of the proposed device, section; in FIG. 2 is a cross section AA in FIG. 1; in FIG. 3 is a longitudinal section BB in FIG. 1 in the plane of a turn of 90 ^o ; in FIG. 4 insert in the context of the image of the rays, providing registration of the tangential and radial components of the deviations; in FIG. 5 is a block diagram of a channel for recording radial beats of a rotor; in FIG. 6, 7 of the position of the unbalanced mass vector during the formation of the extrema of the photoconversion signal; in FIG. 8, 9 arbitrary coordinate positions of the unbalanced mass vector relative to the raster mark; in FIG. 10 diaphragms of the positions of the extremum signal relative to the reference mark signal according to two examples of the position of the unbalanced mass; in FIG. 11 - wavefront propagation from secondary A, B sources; in FIG. 12 - the course of the rays in the optical wedge disk; in FIG. 13 registration scheme.

Accepted designations:
Δα is the angle of the optical wedge disk (Fig. 1);
g the angle of the position of the forming optics of the Fourier spectrometer of the channel recording radial beats of the rotor;
w angular frequency of rotation of the rotor;
l ₁ , l ₂ optical paths of the split components;
± Δl increment of the optical path;
Φ ₁ ; Φ ₂ angular coordinates of the unbalanced mass vector (Fig. 6 8);
W _e designation of an extremum momentum;
W _t designation of the impulse reference marks;
β the beam deflection angle (Fig. 11) relative to the radius of the vector.

A device for recording deviations of the axis of rotation of a dynamic object includes a housing 1 (Fig. 1) with supporting cylindrical 2 and flat 3 surfaces, a rotor 4, a floating sleeve 5 with an outer spherical surface 6, forming an aerostatic bearing with a spherical surface 7 of the rotor, channels 8 for supply a working medium under pressure in the working gaps of the sliding planes, a liner 9 with a cylindrical inner surface 10, a radiation source 13 rigidly covered by hemispherical segments 11, 12 of the rotor 4, a beam splitter 14, form optics 15, reflectors 16 18 (Fig. 1, 2, 3), matrices 19 21 photodetectors, registration scheme 22, second beam splitter 23, corner reflectors 24 27. Insert 9 is made in the form of an optical wedge disk with an input annular diaphragm 28 (Fig. 4) and with total internal reflection upon exit along the inner cylindrical surface 10 (Figs. 1, 4). The beam splitters 14, 23 are mounted axially with an angular offset of the surfaces of the beam splitters by 90 ^o .

The optical rotor position sensor is made three-channel, and the forming optics in each channel are indicated:
15, 29 micro-lenses for recording the tangential component of the deviations of the axis of rotation;
28 micro-lens Fourier spectrometer;
30 o-rings;
31 spacer rings;
32 compensation masses;
33, 34 collectors of worked-out flows of the working medium (Fig. 3);
35 cavity accumulation of the working environment;
36 cavity elastic damping;
37 channel connection with the atmosphere;
38 segment belt of the housing 1 in the form of a cylindrical reflector (Fig.2, 4).

 The registration circuit 22 contains (Fig. 1, 5) three channels (one is shown), each of which includes blocks 39 of photoconverting elements with amplifiers, an analog-to-digital converter 40, an extremum driver 41, an OR element 42, a counter 43, a multiplexer 44 , block 45 RS-flip-flops, block 46 display, RS-flip-flop 47 control.

 The extremum shaper consists of blocks 48, 49 of D-flip-flops, block 50 of inverters and a logical element n AND-OR 51.

 The analog-to-digital Converter 40 contains threshold elements 52 of discrete thresholds of operations with increasing index order.

 Position 53 (Fig. 5, 8, 9) denotes a raster sensor reference marks (the origin of the angular coordinate).

 The sensor is an optocoupler m, rigidly connected to the housing, and a raster gradation m 'on the rotor.

The operation of the registration channel of the radial beat of the rotor is based on a change in the optical path difference of the components W ₁ , W _{2 of the} split coherent beam. Consolidated by means of forming optics 28 in focus on the surface of the matrix of photodetectors 20 (Fig. 2, 11) (Fourier spectrometer). On the second and third channels, the face beats of the rotor 4 are recorded with tangential deviations of the axis of rotation. The beam from the source 13 (Fig. 1) passes the beam splitter 23, forming the first component W ₁ by means of reflectors 16, 18, and on the beam splitter 14 (Fig. 1, 2) a component W ₂ is formed by means of reflectors 16, 17 (Fig. 1, 3 ) By means of angular reflectors 24 27 and a wedge-shaped disk 9, optical levers are formed with annular diaphragm 28 (Fig. 4) with positions of the positions of the spots of the ray components on the photodetector arrays 19 and 21.

The operation of the registration channels of tangential deviations of the axis of rotation is based on the displacements of the spots of rays on the matrices of photodetectors with angular movements of the optical levers. The phase of the two photoconversion signals along the channels of the secondary sources A, B after the reflection is shifted 90 ^° , and the signals reflect the end beats of the reflection surface of the optical disk 9. The phase shift allows you to determine the coordinate dynamic state of the position of the axis of rotation relative to the reference signal and produce the necessary axial movement of the compensation mass, minimizing end-beat. Wave fronts of rays W ₁ ; W ₂ propagate with reflection from the end planes of the wedge disk 9 in the direction of the angle solution (Fig. 4, 12). It is permissible to consider the main harmonics of these rays as emanating from secondary sources A and B (Fig. 11). The direction vector of each beam is deflected by an angle b from the radius vector, and the parasitic components are suppressed by the antireflection coating of the output cylindrical surface 10 of the wedge disk 9 (Fig. 1), and also due to the difference in the angle of incidence on the forming optics 28 of the Fourier spectrometer. On the surface of the matrix 20 of photodetectors (Fig. 11), the wave fronts of the reflected components of the coherent beam interfere, and the position of the gradation fronts of the interferogram is determined by the varying difference in the course of the interfering rays. The condition for amplification of waves from a coherent source with an optical path difference of two rays:
d = n ₂ r ₂ -n ₁ r ₁ = mλ (m = 0; ± 1, ± 2, ...)
where δ is the optical path difference;
n ₁ ; n ₂ refractive indices of the media;
m is the number of orders (BM Yavorsky et al. Physics Reference Manual M. Nauka. 1979, p. 324).

Wave attenuation condition:
d = n ₂ r ₂ -n ₁ r ₁ (2m-1) λ / 2 (m = 0; ± 1; ± 2, ...)
Constant pressure is created in the storage cavity 35 (Fig. 3), since the total area of the passage sections of the flow channels of the floating sleeve 5 is significantly smaller than the cross section of the bypass channel for supplying the working medium to this cavity. The centering of the floating sleeve 5 is determined by the expiration of the working medium into symmetrical cavities 36 of elastic damping through the bypass channels of the housing 1 (Fig. 1) of small cross section. Similarly, the fluid flows through the bypass channels of the floating sleeve 5 into the gap between the spherical surfaces 6, 7. This determines the stiffness of the centering of the rotor 4 relative to the floating sleeve 5. Comparing the stiffness of centering the floating sleeve relative to the housing, we can conclude that these stiffnesses differ by an order of magnitude. since, with identical radial gaps of the order of 6 μm, the number of flow channels at the floating sleeve is greater, namely in each row, and in the housing 4 in each row with passage sections diameter of 0.1 mm at the expiration of each channel. The radial clearance of the drive cavity 35 (Fig. 3) is 1 mm, therefore, the free flow of the working medium from one changing part of the volume to another is ensured during radial movements of the floating sleeve 5. Therefore, the pressure in this cavity itself does not play a noticeable role in centering, but the stiffness of the centering of the elements under consideration is determined by the jet effect of the expiration. The spent working medium is removed along the peripheral radial slots of the gaps through the collectors 33 and 34 and the channels 37 of the outflow into the atmosphere. The collectors 33 and 34 together with the channels 37 provide uniform outflow and the same conditions with the corresponding averaging of fluctuations. In the dynamic state of the rotor, the working medium is fed through the bypass channels 8 of the housing 1 (Fig. 1, 3) into symmetrical cavities 36, providing centering of the floating sleeve 5 during the jet flow of the working medium, and the cavity 35 provides a jet flow under pressure into the gap between the floating sleeve 5 and rotor 4.

 In dynamics, the rotor 4 is self-centered with respect to the axis of inertia with self-compensation of the residual unbalanced mass, and the floating sleeve 5 is radially displaced relative to the housing 1 without rotation, held by the friction of the spring-loaded o-rings 30. In the dynamic state of the rotor 4 with an unbalanced mass, the rotor axis of nominal position, and the gap between the spherical surfaces of the rotor and the floating sleeve 5 changes, while the vector of this change makes a circular rotation with h rangefinders rotation of the rotor (Figs. 6, 7). This periodically changes the optical difference in the path of the rays along the registration channel of the radial beat of the rotor and causes the displacement of the interferogram bands and, accordingly, the amplitude changes of the photoconversion signal at the output of block 39 (Fig. 5). The deviation of the rotor of the center is associated with the action of centrifugal force on the unbalanced mass and this can be approximated by a rotating vector in a circle.

 Consider the process of generating an extremum signal. In the position of the unbalanced mass vector in FIG. 6, 7, the optical paths of the rays of the secondary sources A, B can be represented by the table.

where l ₁ ; l ₂ optical paths of rays W '₁; W ' ₂ secondary sources;
Δl increments due to radial deviations of the rotor.

The formation of an extremum will occur
for l ₁ l ₂ (1),
due to symmetry, i.e. in the position of the unbalanced mass vector of FIG. 8, 9.

 The operation of the elements of the channel recording radial beats is as follows.

Let there be an increase in the amplitude of the W-signal of photoconversion and after the triggered threshold elements 52.1 of FIG. 5, element 52 is triggered. 2. Since the logic unit (1) is at the D-input of trigger 48.2, the positive difference (0 → 1) at the C-input of this trigger causes it to trigger and prepare for operation at the D-input of trigger 49.2 with simultaneous supply the log. units to the first input of the second coincidence element as part of logical element 51. The difference (1 → 0) will take place at the moment in question at the C-input of the D-flip-flop 49.2, however, this trigger only works if there is a positive difference (0 → 1), on The C-input from inverting the signal on the inverter 50.2, which can only occur if an extremum signal is formed when the amplitude of the W-signal decreases and the threshold element 52.2 returns to its original state. In this case, the operation of the D-flip-flop 49.2 causes a coincidence on the second matching element of the logical element 51, and a short pulse is generated at its output, by which all the D-flip-flops on the R-inputs of the extremum 41 return to their original state and at the same time, resetting is performed on the R-input counter 43, in which the information on the triggering of D-triggers of block 48 is provided by the logical element OR 42. The number of triggered triggers of block 45 is fixed in counter 43 and this gives digital information about the amplitude of the signal topreobrazovaniya. The indication by the block 46 of indicators during the transition period of the change of states is prohibited for the states of the RS flip-flop 47 triggered with the arrival of the first pulse of the clock of the counter 43. When the flip-flop returns to its initial state by the R-input W _m- signal of the sensor 53 of the reference mark, the resolution is displayed. An n-number of indicators is excited in accordance with the unbalance value and the rotor radial deviation. At a sufficiently high speed, a stroboscopic effect of inertia of vision takes place and the operator can draw a conclusion about the magnitude of the radial unbalance. If necessary, product certification during operation is recorded on digital printing, which gives information about deviations of the axis of rotation of the rotor.

 Consider the formation of information on the phase position of the unbalanced mass in the dynamic state of the rotor.

Let the reference mark m 'of the raster sensor 53 (Fig. 8, 9) occupy an arbitrary position in the angular coordinate system relative to the optocouplers of this sensor fixed on the housing 1 in the position of the rotor unbalance vector with equal optical paths of the rays l ₁ l ₂ (Fig. 1).

где Φ₁, Φ₂ фазовое положение m';
τ₁; τ₂ периоды при ω = const.We have:

where Φ ₁ , Φ ₂ phase position m ';
τ ₁ ; τ ₂ periods at ω = const.

The formation of an extremum signal (W _e pulse) and the formation of a signal of a reference mark sensor 53 (W _t pulse) are reflected in the diagrams in FIG. 10.

 The phase position of the unbalanced mass vector is implemented by hardware, which follows from the considered functioning of the registration scheme. As for the movements of the compensation mass to reduce the unbalance, this can be done manually or automatically, for example, by the method of drip deposition, by the method of laser evaporation, simple mass transfer, etc. The work and structure of the tangential component are similar to the channel considered. In relation to the base object, the considered technical solution is more informative. The design of the device provides a compensation installation of residual unbalanced masses, since the rotor is self-centering in a dynamic state at a supercritical speed with radial movements of the floating sleeve, and the working medium under pressure plays the role of the elastic element.

 The balance state of the rotor by the radial and tangential components of the deviations is recorded according to the optical sensor. The increased sensitivity of the device is achieved due to the optical lever using structural elements with a double path of split beams along the tangential component, and along the radial component using optical fibers on the structural elements using the principle of detecting deviations in changes in the optical path difference on a Fourier spectrometer. A change in the path of the rays of the fundamental harmonics of the split beams occurs with the effect of multiplication by the number of reflections and this achieves increased sensitivity with radial beats of the rotor.

 The proposed device allows you to measure deviations of the axis of rotation of the object in the process and thereby to carry out certification control with the guaranteed quality of the optical recording.

 In comparison with the base object, the sensitivity is increased several times and the device is multifunctional, since it is possible to perform selective balancing of a dynamic object: separately to reduce the tangential and radial components of the deviations of the rotation axis. At the same time, the combination of functions of structural elements was achieved. TTT1 YYY1 YYY2 YYY3 YYY4 YYY5 YYY6 YYY7 YYY8 YYY9 YYY10 YYY11 YYY12

Claims (1)

 A device for recording deviations of the axis of rotation of an object, containing an aerostatic support for rotation of an object mounted on a rotor, including a housing with supporting cylindrical and flat surfaces, and also a floating sleeve located between the housing and the rotor with an outer spherical surface, forming an aerostatic bearing with the spherical surface of the rotor , channels for supplying a working medium under pressure to the working gaps of the sliding planes, a liner rigidly covered by hemispherical segments of the rotor , a position sensor of an object mounted on the rotor, including an optoelectronic circuit for recording the magnitude of the radial and axial deviations of the axis of rotation of the object, containing a coherent radiation source, a beam splitter, a photodetector array, a reflector forming optics, said registration circuit including triggers, analog-to-digital blocks transducers, amplifiers, OR elements and matches, converters and synchronization circuit, characterized in that it contains one of the hemispherical segments of the rotor and the liner filled with optically transparent, while the insert is made in the form of an optical wedge disk with an input annular diaphragm and with full internal reflection, the introduced second beam splitter is deployed relative to the first by an angle π / 2 in the plane normal to the central axis of the rotor, and two additionally introduced photodetector arrays are designed for optical communication with the reflective coating of the rotor, and all three photodetector arrays form, together with micro-lenses in the optical channels, Fourier spectrometers coupled to by a wedge-shaped rotor element, two of the photodetector arrays are installed along the rays through the dividing planes of the beam splitters, and the third in the body of the floating support sleeve is equidistant from the two channels of the rays in the wedge element of the rotor, the photodetector matrixes are connected to a three-channel recording circuit, each of which channels includes self-connected photoconverting elements with amplifiers, an analog-to-digital converter and an extremum shaper, channels, one of which is a channel for beats, and other channels of the tangential component, the first outputs are connected respectively to two elements of the same name, and two of the opposite channels are group outputs connected to the inputs of the OR elements, the outputs of which are connected to the second inputs of the said blocks, and the third inputs of these blocks are connected respectively to the sensors the position of the object and the output of one of the channels of the tangential component, while each of the blocks contains a counter connected to the control input of the multiplexer, a block of RS triggers, soy shared with the signal buses of this multiplexer and with digital indicators, and the RS-trigger for controlling these indicators, while the counter zeroing input forms the first input of the block, the S-input of the RS-trigger setup with the combined clock C-input of the counter form the second block input, and the combined The R-inputs of the installation of the RS-trigger control and the block of RS-flip-flops form the third input of each of the blocks, while on the signal bus of the input of the multiplexer in each of the blocks there is a constant potential "logical unit", while the first outputs of all three ex channels are the outputs of the extremum shapers, two of which in the opposite channels form group outputs.

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