rus
Issue #6/2020
B.G.Turukhano, N.Turukhano, S.N.Khanov, Yu.M.Lavrov, L.A.Konstantinov, O.G.Ermolenko, V.V.Dobyrn, R.P. Sinelshchikova
Tests of high-precision spindles using LHIIS holographic nano-measuring systems
Tests of high-precision spindles using LHIIS holographic nano-measuring systems
DOI: 10.22184/1993-8578.2020.13.6.384.390
It was studied the radial and axial runout of a spindle using precision nano-holographic measuring systems – linear and angular displacements – length meters and an ultra-precision rotary table. Spindle rotation accuracy was estimated by the value of radial and axial wavering of its front end. The spindle carries out a mechanical rotational movement. During the rotational movement of the spindle, all its points, including the outer surface, describe circles located in parallel planes. The centers of all circles lie on the same line perpendicular to the planes of circles called the axis of rotation. The axis of rotation of the spindle is located inside it. The wavering of the spindle is examined on its upper and lateral surfaces.
It was studied the radial and axial runout of a spindle using precision nano-holographic measuring systems – linear and angular displacements – length meters and an ultra-precision rotary table. Spindle rotation accuracy was estimated by the value of radial and axial wavering of its front end. The spindle carries out a mechanical rotational movement. During the rotational movement of the spindle, all its points, including the outer surface, describe circles located in parallel planes. The centers of all circles lie on the same line perpendicular to the planes of circles called the axis of rotation. The axis of rotation of the spindle is located inside it. The wavering of the spindle is examined on its upper and lateral surfaces.
Теги: high-precision spindles lhiis holographic nano-measuring systems высокоточные шпиндели голографические наноизмерительные системы лгиис
INTRODUCTION
When rotating around a fixed axis, the rotational movement is called circular. If the spindle axis changes its position during the circular movement of its points, then the so-called beats appear at the spindle. In this case, the beats can be both in a plane perpendicular to its axis (radial beating) and in the direction of the spindle axis itself (axial beating).
The limiting values of these beats for research or other work, as well as devices, are determined depending on the required rotation accuracy. For universal machine tools of specific accuracy classes, beats are set by GOSTs, and to ensure the required spindle rotation accuracy, bearings are selected for it, the accuracy of which is approximately three times more accurate than the permissible spindle runout. To measure the beats of the spindle, we used holographic length meters DG-30 and DG-100 with the characteristics given in Table 1. Table 2 shows the characteristics of an ultra-precision two-spindle nano-measuring holographic single-axis rotary table NIPSG [1–3].
We develop and create the long length meters of holographic DG-30 and DG-100 with various display systems. For DG-30, the output of results can be organized both on a personal computer screen and on an autonomous display unit, and DG-100 is mainly used with an autonomous unit for indicating a signal from a measuring installation.
Figure 3 shows a general view of the holographic sensor stand installed on an ultra-precision two-spindle nano-measuring holographic single-axis rotary table NANO IPS-2, the characteristics of which are given in Table 2. The length of the holographic DG-100 is built into the stand for studying the roundness of parts and their radial and axial beating.
MEASUREMENTS AND RESULTS
Figure 1 shows an ultra-precision two-spindle nano-measuring single-axis holographic rotary table (NIPSG) and a NANO IPS-2 stand [4–6].
Characteristics of the stand of the holographic NANO IPS-2 [4,5]:
for certification of angle sensors, optical elements and other elements;
certification of devices without / with inertial load 0.02 Nm / 50 Nm.
Using the NANO IPS-2 stand (Fig.1), the radial beats of the spindle of a nano-measuring single-axis holographic rotary table (Fig.2) were studied.
As can be seen from the graph in Fig.3, the radial beating curve of the spindle of the NANO IPS-2 rotary table changes from 0.05 μm to 0.38 μm per spindle revolution (three rotations were performed, the repeatability was ± 0.1 μm). Note that these values do not include the manufacturing accuracy of the outer surface of the spindle, since the beats were determined using a spherical standard centered on the surface of the rotary table – NANO IPS-2.
As can be seen from the graph in Fig.6, the axial beats of the spindle of the NANO IPS-2 rotary table vary from 0.2 μm to 0.45 μm.
The spindle "Ш8" was tested in the Laboratory of Information and Measuring Systems (LGIIS) – PNPI using the device "Holographic length meter DG-30" of Russian manufacture (LGIIS) and recognized as a measuring instrument according to the "Certificate of verification" issued by the State commttee of the RF for standardization and metrology gosstandard of Russia) No. 112511-7-121 / 10 and "Certificate of type approval of measuring instruments" RU.C.27.001.A No.
100899 "issued by the Federal Agency for Technical Regulation and Metrology. The DG-30 accuracy is +/–0.05 microns, the resolution is 10 nm at a length of 30 mm. The DG-30 device was verified in October 2018. The measurements were carried out along three polished rotor tracks (a, b, c) according to previous figure. The tests were repeated twice, forward and backward. The results are presented graphically in Figures 4–11.
Track c scan is shown in Fig.5.
The results of the scans of track b and the spindle runout during clockwise and counterclockwise rotation are shown in Fig.6.
Track a scan is shown in Fig.7.
Then a comparison was made of the tracks while rotating the spindle clockwise forward.
Thereafter, the tracks were compared while rotating the spindle counterclockwise forward.
CONCLUSIONS
It can be seen that the detected maxima and minima of the curves obtained with spindle rotations "clockwise" and "counterclockwise" are practically the same.
Maxima: the values showing the maxima of the curves "clockwise" and "counterclockwise" (Fig.8 and 9), when the spindle rotor rotates, are the same with an error less than 0.3 µm.
Minima: the values showing the minima of the curves "clockwise" and "counterclockwise" (Fig.8 and 11), when the spindle rotor rotates, are also the same with an error less than 0.3 µm. ■
When rotating around a fixed axis, the rotational movement is called circular. If the spindle axis changes its position during the circular movement of its points, then the so-called beats appear at the spindle. In this case, the beats can be both in a plane perpendicular to its axis (radial beating) and in the direction of the spindle axis itself (axial beating).
The limiting values of these beats for research or other work, as well as devices, are determined depending on the required rotation accuracy. For universal machine tools of specific accuracy classes, beats are set by GOSTs, and to ensure the required spindle rotation accuracy, bearings are selected for it, the accuracy of which is approximately three times more accurate than the permissible spindle runout. To measure the beats of the spindle, we used holographic length meters DG-30 and DG-100 with the characteristics given in Table 1. Table 2 shows the characteristics of an ultra-precision two-spindle nano-measuring holographic single-axis rotary table NIPSG [1–3].
We develop and create the long length meters of holographic DG-30 and DG-100 with various display systems. For DG-30, the output of results can be organized both on a personal computer screen and on an autonomous display unit, and DG-100 is mainly used with an autonomous unit for indicating a signal from a measuring installation.
Figure 3 shows a general view of the holographic sensor stand installed on an ultra-precision two-spindle nano-measuring holographic single-axis rotary table NANO IPS-2, the characteristics of which are given in Table 2. The length of the holographic DG-100 is built into the stand for studying the roundness of parts and their radial and axial beating.
MEASUREMENTS AND RESULTS
Figure 1 shows an ultra-precision two-spindle nano-measuring single-axis holographic rotary table (NIPSG) and a NANO IPS-2 stand [4–6].
Characteristics of the stand of the holographic NANO IPS-2 [4,5]:
for certification of angle sensors, optical elements and other elements;
certification of devices without / with inertial load 0.02 Nm / 50 Nm.
Using the NANO IPS-2 stand (Fig.1), the radial beats of the spindle of a nano-measuring single-axis holographic rotary table (Fig.2) were studied.
As can be seen from the graph in Fig.3, the radial beating curve of the spindle of the NANO IPS-2 rotary table changes from 0.05 μm to 0.38 μm per spindle revolution (three rotations were performed, the repeatability was ± 0.1 μm). Note that these values do not include the manufacturing accuracy of the outer surface of the spindle, since the beats were determined using a spherical standard centered on the surface of the rotary table – NANO IPS-2.
As can be seen from the graph in Fig.6, the axial beats of the spindle of the NANO IPS-2 rotary table vary from 0.2 μm to 0.45 μm.
The spindle "Ш8" was tested in the Laboratory of Information and Measuring Systems (LGIIS) – PNPI using the device "Holographic length meter DG-30" of Russian manufacture (LGIIS) and recognized as a measuring instrument according to the "Certificate of verification" issued by the State commttee of the RF for standardization and metrology gosstandard of Russia) No. 112511-7-121 / 10 and "Certificate of type approval of measuring instruments" RU.C.27.001.A No.
100899 "issued by the Federal Agency for Technical Regulation and Metrology. The DG-30 accuracy is +/–0.05 microns, the resolution is 10 nm at a length of 30 mm. The DG-30 device was verified in October 2018. The measurements were carried out along three polished rotor tracks (a, b, c) according to previous figure. The tests were repeated twice, forward and backward. The results are presented graphically in Figures 4–11.
Track c scan is shown in Fig.5.
The results of the scans of track b and the spindle runout during clockwise and counterclockwise rotation are shown in Fig.6.
Track a scan is shown in Fig.7.
Then a comparison was made of the tracks while rotating the spindle clockwise forward.
Thereafter, the tracks were compared while rotating the spindle counterclockwise forward.
CONCLUSIONS
It can be seen that the detected maxima and minima of the curves obtained with spindle rotations "clockwise" and "counterclockwise" are practically the same.
Maxima: the values showing the maxima of the curves "clockwise" and "counterclockwise" (Fig.8 and 9), when the spindle rotor rotates, are the same with an error less than 0.3 µm.
Minima: the values showing the minima of the curves "clockwise" and "counterclockwise" (Fig.8 and 11), when the spindle rotor rotates, are also the same with an error less than 0.3 µm. ■
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