CN203908522U - Spindle revolution error measuring device capable of separating mounting eccentricity - Google Patents

Abstract

The utility model discloses a spindle revolution error measuring device capable of separating mounting eccentricity. The spindle revolution error measuring device includes a displacement sensor mounting clamp, a displacement sensor, a grating encoder, a signal cable, a data processor and a computer. The displacement sensor is installed in the middle part of the displacement sensor mounting clamp. The displacement sensor mounting clamp is installed on one side adjacent to the outer periphery of a spindle. The grating encoder is installed on the other side adjacent to the outer periphery of the spindle. The grating encoder and the displacement sensor are connected with the data processor through the signal cable. The data processor is connected with the computer. According to the utility model, roundness errors of a spindle profile and eccentricity errors of the mounting of a standard ball and the sensor are separated from spindle revolution motion errors on one hand, so that the separation operation load is small. On the other hand, only one displacement sensor is adopted, so that measurement errors due to sensor performance difference of three sensors adopted in a common three-point error separation technique are avoided. Therefore, the spindle revolution error measuring device has a value of promotion and application.

Description

A kind of spindle rotation error measurement mechanism that is removably installed eccentric

Technical field

The utility model relates to a kind of exact instrument and manufactures measurement mechanism, relates in particular to a kind of spindle rotation error measurement mechanism that is removably installed eccentric.

Background technology

High-precision main shaft, air bearing are the critical components of the precision assemblies such as precision finishing machine, precision centrifuge, disc driver, high-accuracy electric rotating machine and steam turbine, affect the many factors of precision optical machinery machining precision (such as: process hot error, structural failure, power chain error, spindle rotation error etc.) in, what part's machining errors was had to the most directly impact is main shaft gyration kinematic error, and its precision is the key of the processing of restriction precision optical machinery, high-precision rotary.Along with the machining precision of lathe reaches even nanometer scale of sub-micron, the part's machining errors that spindle rotation error causes becomes the major influence factors of restriction precision optical machinery machining precision.Correlation test shows that the part deviation from circular from of precision turning processing approximately has 30%～70%, caused, and the precision of lathe is higher by the spindle rotation error of lathe, and its main shaft gyration kinematic error shared ratio in various mismachining tolerances source is larger.

In the situation that current spindle rotation error measuring principle and technological means can not fundamentally change, owing to cannot directly desirable axle center being measured, and must, by the measurement of standard ball, standard axle or main shaft outline being recorded indirectly to the gyration error size of main shaft, so just unavoidably can sneak into shape error, surface waviness, surfaceness and the standard ball of standard ball, standard axle itself or main shaft outline, the setting-up eccentricity equal error source of standard axle.Therefore, the key of main shaft gyration kinematic error measuring technique is that error is separated.When measuring accuracy enters sub-micron even during nanometer scale, deviation from circular from, surfaceness and the setting-up eccentricity etc. that are blended in measurement data will highlight, and even can mask the gyration error that main shaft is small.Therefore must take effective method, gyration error is accurately separated from measurement result.Traditional motion of main shaft turn error measuring method is as adopted clock gauge to measure main shaft run-out, and measuring accuracy is very low, the deviation from circular from of main shaft can not be separated from gyration error.

At present, main shaft gyration kinematic error measuring method mainly contains reversal process, multistep processes and many gauge heads method.Although correlative study shows three kinds of methods, respectively have relative merits, as long as appropriate design parameter, three kinds of methods can reach nanometer measurement precision.Yet reversal process and multistep processes are mainly used to the deviation from circular from of part to detect, can not measure online, in real time the gyration error of axle system.Multipoint method mainly contains two-point method, three point method, four-point method etc. according to the number of sensor installation, since Japanese scholars Ozono in 1966 proposes after classical frequency domain Three Point Method for Error Separation of Roundness first, this technology has become at present one of the most widely used error separating technology.Its advantage be can on-line real time monitoring axle the gyration error of system.

In deviation from circular from based on three point method and spindle rotation error measuring technique, it is the key that improves error separation accuracy that the harmonic wave that how to reduce error separation suppresses, reduces measuring error transmission.The known main shaft gyration kinematic error measuring method based on Analyses of Error Separation Techniques mainly contains based on two kinds of frequency-domain and time-domains at present.Due to the humorous inhibition of single order, cause containing in spindle rotation error measurement result standard ball setting-up eccentricity, three sensor axis intersection points do not overlap with the centre of gyration and the eccentric error introduced.For this problem, a kind of modified three point method of Chinese patent turn error, deviation from circular from computing method (patent application publication number: CN103363921A, author Niu Baoliang, Zhang Rong) a kind of deviation from circular from and turn error separation method based on three point method proposed, its principal feature is to utilize translation and the weighted mean of three sensor output signals, and utilize frequency domain filtering, an order harmonic component of shape error is separated from deviation from circular from and turn error.In addition, the virtuous minister in ancient times of Xi'an University of Technology's thunder is in (the cylindricity Technology of Precision Measurement research based on error separation of its PhD dissertation, Xi'an University of Technology's PhD dissertation, 2007) in, adopt a kind of Time-Domain algorithm that deviation from circular from, spindle rotation error and setting-up eccentricity are carried out to separation.These methods are deepened and have been developed error separating technology, but still have the deficiencies such as computing complexity.And during the deviation from circular from based on three point method and spindle rotation error are measured, How to choose sampling number and error how to avoid three displacement transducer performance differences to introduce are the sub-micron problems that even nanometer scale high-acruracy survey should be considered.

Utility model content

The purpose of this utility model provides a kind of spindle rotation error measurement mechanism that is removably installed eccentric with regard to being in order to address the above problem.

The utility model is achieved through the following technical solutions above-mentioned purpose:

The spindle rotation error measurement mechanism that is removably installed eccentric described in the utility model, comprise displacement transducer installing holder, displacement transducer, grating encoder, signal cable, data acquisition unit, data processor and computing machine, described displacement transducer is installed on described displacement transducer installing holder, described displacement transducer installing holder is installed near main shaft excircle place, between described displacement transducer clamper and main shaft outline, be provided with space, described grating encoder is installed on main shaft sleeve, described grating encoder is all connected with described data processor by described signal cable with described displacement transducer, described data processor is connected with described computing machine.

Particularly, described data processor is comprised of data acquisition unit and signal conditioner; Described displacement transducer installing holder is for can install the displacement transducer installing holder of one or three displacement transducer simultaneously.

The beneficial effects of the utility model are:

The utility model is a kind of spindle rotation error measurement mechanism that is removably installed eccentric, compared with prior art, the utility model is separated the eccentric error of the deviation from circular from of main shaft profile, standard ball and installation of sensors on the one hand from main shaft gyration kinematic error, and separation algorithm amount is little.On the other hand, only adopt a displacement transducer, the measuring error of having avoided adopting in common Analyses of Error Separation Techniques sensor performance difference that three sensors bring to introduce, has the value of promoting the use of.

Accompanying drawing explanation

Fig. 1 is hardware configuration schematic diagram of the present utility model;

Fig. 2 is method flow diagram of the present utility model;

Fig. 3 is displacement transducer installation site conversion regime one schematic diagram;

Fig. 4 is displacement transducer installation site conversion regime two schematic diagram;

Fig. 5 is displacement transducer installation site conversion regime three schematic diagram.

In figure: 1-main shaft, 2-displacement transducer installing holder, 3-displacement transducer, 4-main shaft outline first sampling point A, 5-main shaft outline first sampling point B, 6-main shaft outline first sampling point C, angle between 7-main shaft outline first sampling point A and first sampling point B, angle between 8-main shaft outline first sampling point A and first sampling point C, the sensor installation hole of 9-displacement transducer installing holder, the sensor installation hole of 10-displacement transducer installing holder, the sensor installation hole of 11-displacement transducer installing holder, 12-grating encoder, 13-signal cable, 14-data acquisition unit, 15-signal conditioner, 16-computing machine.

Embodiment

Below in conjunction with accompanying drawing, the utility model is described in further detail:

As shown in Figure 1: the spindle rotation error measurement mechanism that is removably installed eccentric described in the utility model, comprise displacement transducer installing holder (2), displacement transducer (3), grating encoder (12), signal cable (13), data processor and computing machine (16), displacement transducer (3) is installed on displacement transducer installing holder (2), displacement transducer installing holder (2) is installed near main shaft (1) excircle place, between displacement transducer clamper (2) and main shaft (1) outline, be provided with space, grating encoder (12) is installed on main shaft (1) axle sleeve, grating encoder (12) is all connected with data processor by signal cable (13) with displacement transducer (3), data processor is connected with computing machine (16), data processor is comprised of data acquisition unit (14) and signal conditioner (15), displacement transducer installing holder (2) is for can install the displacement transducer installing holder of one or three displacement transducer simultaneously.

As shown in Figure 2: the spindle rotation error measuring method that is removably installed eccentric described in the utility model, comprises the following steps:

(1) displacement transducer clamper (2) is arranged on main shaft (1) excircle, and and there is space between main shaft (1) outline, displacement transducer (3) is arranged on to displacement transducer clamper (2) upper, regulates the gauge head of displacement transducer (3) and the distance between main shaft (1) outline to arrive correct position; Main shaft (1) is set, and to return the displacement transducer sampling number circle be N;

(2) drive shaft (1) rotation, the first sampling point (being designated as A point) that the initial point of main shaft (1) outline of take is displacement transducer (3), main shaft (1) revolves and turns around, and N value of displacement transducer (3) sampling output, is designated as { S successively ₀(0), S ₀(1), S ₀(2) ..., S ₀(N-1) }; And using displacement transducer (3) displacement transducer (3) the sensitive axes direction that initially first sampling point is corresponding as the x axle of measuring coordinate system;

(3) by one of following three kinds of modes by sensor along main shaft (1) profile anglec of rotation α, this angle is the angle of first sensor and second sensor in three point method error separation principle, its selection will guarantee that three point method harmonic wave suppresses minimum; Corresponding discrete value is P ₁=α N/2 π, P ₁for integer:

First kind of way: displacement transducer clamper (2) maintains static, utilize positioning function drive shaft (1) anglec of rotation α of grating encoder (12), the first sampling point for the second time that makes displacement transducer (3) is the position (being designated as B point) with respect to first sampling point distance alpha angle in step (2);

The second way: rotary displacement transducer clamper (2), make displacement transducer clamper (1) drive displacement transducer (3) along main shaft (1) profile same cross section anglec of rotation α, holding position displacement sensor (3) is not axially beated at main shaft (1) as far as possible, and displacement transducer (3) sensitive axes orientation of its axis main shaft (1) centre of gyration;

The third mode: displacement transducer clamper (2) is designed to install the shape of three displacement transducers (3) simultaneously, angle between first displacement transducer (3) installation site and second displacement transducer (3) installation site is designed to α angle, angle between first displacement transducer (3) installation site and the 3rd displacement transducer (3) installation site is designed to β angle, angle design between three displacement transducers (3) installation site meets minimum harmonic wave rejection condition, three displacement transducers (3) installation site is designated as respectively A, B, C point, wherein A point is the initial sampled point of displacement transducer (3) in step (1), displacement transducer (3) is shifted and is installed to B point from A point, holding position displacement sensor (3) sensitive axes orientation of its axis main shaft (1) centre of gyration as far as possible,

(4) using the new position of displacement transducer (3) as first sampling point, main shaft (1) revolves and turns around, and N value of sensor sample output, is designated as { S successively ₁(0), S ₁(1), S ₁(2) ..., S ₁(N-1) };

(5) measuring process of repeating step (3) and (4), different is that displacement transducer (3) is β along main shaft (1) the profile anglec of rotation, this angle is the angle of first sensor and the 3rd sensor in three point method error separation principle, and its selection will guarantee that three point method harmonic wave suppresses minimum; Corresponding discrete value is P ₂=β N/2 π, P ₂for integer, using the new position of displacement transducer (3) (being designated as C point) as first sampling point, main shaft (1) revolves and turns around, and N value of sensor sample output, is designated as { S successively ₂(0), S ₂(1), S ₂(2) ..., S ₂(N-1) };

(6) three groups of displacement transducer output data based in step (2), (3), (4), (5), according to the frequency domain in three point method error separation principle or time domain approach, can obtain other value r (n) except an order harmonic component of main shaft (1) deviation from circular from, n=1,2,3,, N-1;

(7) utilize the output data S of three displacement transducers (3) ₀(n), S ₁(n), S ₂(n) and separated except the deviation from circular from r (n) of an order harmonic component, by following algorithm, can obtain Errors in Radial Rotation Error of Spindle by solve linear equations:

$\left[\begin{array}{ccc}\cos (2\mathrm{\πn}/N)& \sin (2\mathrm{\πn}/N)& \cos (2\mathrm{\πn}/N)\\ \cos (2\mathrm{\π}(n+P_1)/N)& \sin (2\mathrm{\π}(n+p_1)/N)& \cos (2\mathrm{\π}(n-p_1)/N)\\ \cos (2\mathrm{\π}(n+P_2)/N)& \sin (2\mathrm{\π}(n+p_2)/N)& \cos (2\mathrm{\π}(n-p_2)/N)\end{array}\right]\·\left(\begin{array}{c}{A}_1\\ B_1\\ \mathrm{\δ}\left(n\right)\end{array}\right)=\left(\begin{array}{c}{S}_0\left(n\right)-r\left(n\right)\\ S_1\left(n\right)-r(n+p_1)\\ S_2\left(n\right)-r(n+p_2)\end{array}\right)$

In formula: A ₁, B ₁for Fourier's frequency domain one order harmonic component of deviation from circular from sine, cosine coefficient in measuring coordinate system, δ (n) is the turn error value of main shaft (1); The cycle of deviation from circular under polar coordinate system is 2 π, for sampling number N, has: r (n+N)=r (n).

Embodiment 1:

As shown in Figure 1: displacement transducer (3) is arranged on displacement transducer clamper (2), the sensitive axes of displacement transducer (3) is aimed at main shaft outline edge or standard ball, after main shaft (1) stabilization of speed, take grating encoder (12) as triggering and positioning signal, main shaft (1) dextrorotation is turned around, displacement transducer (3) gathers N displacement data, is designated as S ₀(θ).As shown in Figure 2, displacement transducer clamper (2) and displacement transducer (3) keep motionless, drive shaft (1) the α angle that turns clockwise, first sampling point as displacement transducer (3), main shaft (1) dextrorotation is turned around, displacement transducer (3) gathers N displacement data, is designated as S ₁(θ); Displacement transducer clamper (2) and displacement transducer (3) keep motionless, drive shaft (1) the β angle that turns clockwise, first sampling point as displacement transducer (3), main shaft (1) dextrorotation is turned around, displacement transducer (3) gathers N displacement data, is designated as S ₂(θ).Three times displacement data is respectively output data S ₀(θ), S ₁(θ), S ₂(θ), wherein θ represents angle of eccentricity, and deviation from circular from r (θ), standard ball and the installation of sensors bias that they have comprised main shaft (1) and spindle rotation error δ (θ), have following relation:

$\left\{\begin{array}{c}{S}_0\left(\mathrm{\θ}\right)=r\left(\mathrm{\θ}\right)+x\left(\mathrm{\θ}\right)\\ S_1\left(\mathrm{\θ}\right)=r(\mathrm{\θ}+\mathrm{\α})+x\left(\mathrm{\θ}\right)\cos \mathrm{\α}+y\left(\mathrm{\θ}\right)\sin \mathrm{\α}\\ S_2\left(\mathrm{\θ}\right)=r(\mathrm{\θ}+\mathrm{\β})+x\left(\mathrm{\θ}\right)\cos \mathrm{\β}+y\left(\mathrm{\θ}\right)\sin \mathrm{\β}\end{array}\right.---\left(A\right)$

In formula: x (θ) and y (θ) are respectively horizontal component and the vertical component of Errors in Radial Rotation Error of Spindle in measuring coordinate system.

Displacement transducer (3) three times output data are weighted and, Rational choice weights coefficient c ₁, c ₂, turn error can be separated from sensor reading.That is:

S(θ)＝S ₀(θ)+c ₁S ₁(θ)+c ₂S ₂(θ)＝r(θ)+c ₁r(θ+α)+c ₂r(θ+β) (B)

In formula (B), weights coefficient c ₁, c ₂get:

$c_1=-\frac{\sin \mathrm{\β}}{\sin (\mathrm{\β}-\mathrm{\α})},c_2=\frac{\sin \mathrm{\α}}{\sin (\mathrm{\β}-\mathrm{\α})}---\left(C\right)$

The round shape error of axle system has footpath tropism and two main geometric properties of periodicity, and the cycle is 2 π.Formula (B) is made to Fourier transform, can obtain the frequency domain character value of main shaft deviation from circular from:

$R\left(n\right)=S\left(n\right)/(1+c_1{e}^{j2\mathrm{\πn}{p}_1/N}+c_2{e}^{j2\mathrm{\πn}{p}_2/N})---\left(D\right)$

Above formula (D) is done to inverse Fourier transform, can obtain the time thresholding of deviation from circular from, but no matter how how angle [alpha], β design, Fourier transform one order harmonic component of deviation from circular from is always suppressed, this order harmonic component is displacement transducer setting-up eccentricity (if while installation code ball, also comprise standard ball setting-up eccentricity) cause, on the measuring accuracy of deviation from circular from and not impact of evaluation, but this measuring error all enters spindle rotation error, affect the measuring accuracy of spindle rotation error.For this reason, based on No. three displacement transducer data, be constructed as follows algorithm:

$\left\{\begin{array}{c}{S}_0\left(n\right)=A_1\cos (2\mathrm{\πn}/N)+B_1\sin (2\mathrm{\πn}/N)+r\left(n\right)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\πn}/N)\\ S_1\left(n\right)=A_1\cos (2\mathrm{\π}(n+p_1)/N)+B_1\sin (2\mathrm{\π}(n+p_1)/N)+r(n+p_1)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\π}(n-p_1)/N)\\ S_2\left(n\right)=A_1\cos (2\mathrm{\π}(n+p_2)/N)+B_1\sin (2\mathrm{\π}(n+p_2)/N)+r(n+p_2)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\π}(n-p_2)/N)\end{array}\right.---\left(E\right)$

Be system of linear equations:

$\left[\begin{array}{ccc}\cos (2\mathrm{\πn}/N)& \sin (2\mathrm{\πn}/N)& \cos (2\mathrm{\πn}/N)\\ \cos (2\mathrm{\π}(n+P_1)/N)& \sin (2\mathrm{\π}(n+p_1)/N)& \cos (2\mathrm{\π}(n-p_1)/N)\\ \cos (2\mathrm{\π}(n+P_2)/N)& \sin (2\mathrm{\π}(n+p_2)/N)& \cos (2\mathrm{\π}(n-p_2)/N)\end{array}\right]\·\left(\begin{array}{c}{A}_1\\ B_1\\ \mathrm{\δ}\left(n\right)\end{array}\right)=\left(\begin{array}{c}{S}_0\left(n\right)-r\left(n\right)\\ S_1\left(n\right)-r(n+p_1)\\ S_2\left(n\right)-r(n+p_2)\end{array}\right)$

According to this system of linear equations, for n=1,2 ..., N, separates the pure Errors in Radial Rotation Error of Spindle value that above-mentioned three rank systems of linear equations can obtain isolating deviation from circular from and setting-up eccentricity.

Embodiment bis-:

As shown in Figure 1: displacement transducer (3) is arranged on displacement transducer clamper (2), the sensitive axes of displacement transducer (3) is aimed at main shaft (1) outline edge or standard ball, after main shaft (1) stabilization of speed, take grating encoder (12) as triggering and positioning signal, main shaft (1) dextrorotation is turned around, displacement transducer gathers N displacement data, is designated as S ₀(θ).As shown in Figure 3: displacement transducer clamper (2) angle [alpha] that turns clockwise, as displacement transducer (3) first sampling point, main shaft (1) dextrorotation is turned around, and displacement transducer (3) gathers respectively N displacement data, is designated as S ₁(θ).Then displacement transducer clamper (2) angle beta that turns clockwise, as displacement transducer (3) first sampling point, main shaft (1) dextrorotation is turned around, and displacement transducer (3) gathers respectively N displacement data, is designated as S ₂(θ).Three times displacement data is respectively output data S ₀(θ), S ₁(θ), S ₂(θ), wherein θ represents main shaft (1) corner, and deviation from circular from r (θ), standard ball and the installation of sensors bias that they have comprised main shaft (1) and main shaft (1) turn error δ (θ), have following relation:

$\left\{\begin{array}{c}{S}_0\left(\mathrm{\θ}\right)=r\left(\mathrm{\θ}\right)+x\left(\mathrm{\θ}\right)\\ S_1\left(\mathrm{\θ}\right)=r(\mathrm{\θ}+\mathrm{\α})+x\left(\mathrm{\θ}\right)\cos \mathrm{\α}+y\left(\mathrm{\θ}\right)\sin \mathrm{\α}\\ S_2\left(\mathrm{\θ}\right)=r(\mathrm{\θ}+\mathrm{\β})+x\left(\mathrm{\θ}\right)\cos \mathrm{\β}+y\left(\mathrm{\θ}\right)\sin \mathrm{\β}\end{array}\right.---\left(a\right)$

In formula: x (θ) and y (θ) are respectively horizontal component and the vertical component of Errors in Radial Rotation Error of Spindle in measuring coordinate system.

Displacement transducer (3) three times output data are weighted and, Rational choice weights coefficient c ₁, c ₂, turn error can be separated from sensor reading.That is:

S(θ)＝S ₀(θ)+c ₁S ₁(θ)+c ₂S ₂(θ)＝r(θ)+c ₁r(θ+α)+c ₂r(θ+β) (b)

In formula (b), weights coefficient c ₁, c ₂get:

$c_1=-\frac{\sin \mathrm{\β}}{\sin (\mathrm{\β}-\mathrm{\α})},c_2=\frac{\sin \mathrm{\α}}{\sin (\mathrm{\β}-\mathrm{\α})}---\left(c\right)$

The round shape error of axle system has footpath tropism and two main geometric properties of periodicity, and the cycle is 2 π.Formula (b) is made to Fourier transform, can obtain the frequency domain character value of main shaft deviation from circular from:

$R\left(n\right)=S\left(n\right)/(1+c_1{e}^{j2\mathrm{\πn}{p}_1/N}+c_2{e}^{j2\mathrm{\πn}{p}_2/N})---\left(d\right)$

Above formula (d) is done to inverse Fourier transform, can obtain the time thresholding of deviation from circular from, but no matter how how angle [alpha], β design, Fourier transform one order harmonic component of deviation from circular from is always suppressed, this order harmonic component is that setting-up eccentricity causes, on the measuring accuracy of deviation from circular from and not impact of evaluation, but this measuring error all enters main shaft (1) turn error, affects the measuring accuracy of main shaft (1) turn error.For this reason, based on No. three displacement transducers (3) data, build following algorithm:

$\left\{\begin{array}{c}{S}_0\left(n\right)=A_1\cos (2\mathrm{\πn}/N)+B_1\sin (2\mathrm{\πn}/N)+r\left(n\right)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\πn}/N)\\ S_1\left(n\right)=A_1\cos (2\mathrm{\π}(n+p_1)/N)+B_1\sin (2\mathrm{\π}(n+p_1)/N)+r(n+p_1)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\π}(n-p_1)/N)\\ S_2\left(n\right)=A_1\cos (2\mathrm{\π}(n+p_2)/N)+B_1\sin (2\mathrm{\π}(n+p_2)/N)+r(n+p_2)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\π}(n-p_2)/N)\end{array}\right.---\left(e\right)$

Be system of linear equations:

$\left[\begin{array}{ccc}\cos (2\mathrm{\πn}/N)& \sin (2\mathrm{\πn}/N)& \cos (2\mathrm{\πn}/N)\\ \cos (2\mathrm{\π}(n+P_1)/N)& \sin (2\mathrm{\π}(n+p_1)/N)& \cos (2\mathrm{\π}(n-p_1)/N)\\ \cos (2\mathrm{\π}(n+P_2)/N)& \sin (2\mathrm{\π}(n+p_2)/N)& \cos (2\mathrm{\π}(n-p_2)/N)\end{array}\right]\·\left(\begin{array}{c}{A}_1\\ B_1\\ \mathrm{\δ}\left(n\right)\end{array}\right)=\left(\begin{array}{c}{S}_0\left(n\right)-r\left(n\right)\\ S_1\left(n\right)-r(n+p_1)\\ S_2\left(n\right)-r(n+p_2)\end{array}\right)$

According to this system of linear equations, for n=1,2 ..., N, separates the Errors in Radial Rotation Error of Spindle value that above-mentioned three rank systems of linear equations can obtain isolating deviation from circular from and setting-up eccentricity.

Embodiment tri-:

As shown in Figure 1 and Figure 4: displacement transducer clamper (2) is designed to the shape of three displacement transducer mounting holes, the angle design between three displacement transducer installation sites is respectively: the angle between first displacement transducer installation site and second displacement transducer installation site is that the angle between α, first displacement transducer installation site and the 3rd displacement transducer installation site is β.First displacement transducer (3) is arranged on the position (11) of clamper, sensitive axes is aimed at main shaft outline edge or standard ball, after main shaft (1) stabilization of speed, take grating encoder (12) as triggering and positioning signal, main shaft (1) dextrorotation is turned around, displacement transducer (3) gathers N displacement data, is designated as S ₀(θ).Displacement transducer (3) is taken off to be in place successively respectively displacement sensor clamper position (9) and position (10) from displacement transducer clamper position (11), sensitive axes is aimed at main shaft outline edge or standard ball, main shaft (1) revolves and turns around successively respectively clockwise, and displacement transducer (3) gathers respectively N displacement data successively.Three times displacement data is respectively output data S ₀(θ), S ₁(θ), S ₂(θ), wherein θ represents angle of eccentricity, and deviation from circular from r (θ), standard ball and the installation of sensors bias that they have comprised main shaft and spindle rotation error δ (θ), have following relation:

$\left\{\begin{array}{c}{S}_0\left(\mathrm{\θ}\right)=r\left(\mathrm{\θ}\right)+x\left(\mathrm{\θ}\right)\\ S_1\left(\mathrm{\θ}\right)=r(\mathrm{\θ}+\mathrm{\α})+x\left(\mathrm{\θ}\right)\cos \mathrm{\α}+y\left(\mathrm{\θ}\right)\sin \mathrm{\α}\\ S_2\left(\mathrm{\θ}\right)=r(\mathrm{\θ}+\mathrm{\β})+x\left(\mathrm{\θ}\right)\cos \mathrm{\β}+y\left(\mathrm{\θ}\right)\sin \mathrm{\β}\end{array}\right.$ ①

In formula: x (θ) and y (θ) are respectively radially horizontal component and the vertical component of turn error in measuring coordinate system of main shaft (1).

Three times of displacement transducer (3) output data are weighted and, Rational choice weights coefficient c ₁, c ₂, turn error can be separated from sensor reading.That is:

S(θ)＝S ₀(θ)+c ₁S ₁(θ)+c ₂S ₂(θ)＝r(θ)+c ₁r(θ+α)+c ₂r(θ+β) ②

Formula 2. in, weights coefficient c ₁, c ₂get:

$c_1=-\frac{\sin \mathrm{\β}}{\sin (\mathrm{\β}-\mathrm{\α})},c_2=\frac{\sin \mathrm{\α}}{\sin (\mathrm{\β}-\mathrm{\α})}$ ③

The round shape error of axle system has footpath tropism and two main geometric properties of periodicity, and the cycle is 2 π.2. formula is made to Fourier transform, can obtain the frequency domain character value of main shaft deviation from circular from:

$R\left(n\right)=S\left(n\right)/(1+c_1{e}^{j2\mathrm{\πn}{p}_1/N}+c_2{e}^{j2\mathrm{\πn}{p}_2/N})$ ④

4. above formula is done to inverse Fourier transform, can obtain the time thresholding of deviation from circular from, but no matter how how angle [alpha], β design, Fourier transform one order harmonic component of deviation from circular from is always suppressed, this order harmonic component is that setting-up eccentricity causes, on the measuring accuracy of deviation from circular from and not impact of evaluation, but this measuring error all enters main shaft (1) turn error, affects the measuring accuracy of main shaft (1) turn error.For this reason, based on No. three displacement transducer data, the following algorithm of member:

$\left\{\begin{array}{c}{S}_0\left(n\right)=A_1\cos (2\mathrm{\πn}/N)+B_1\sin (2\mathrm{\πn}/N)+r\left(n\right)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\πn}/N)\\ S_1\left(n\right)=A_1\cos (2\mathrm{\π}(n+p_1)/N)+B_1\sin (2\mathrm{\π}(n+p_1)/N)+r(n+p_1)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\π}(n-p_1)/N)\\ S_2\left(n\right)=A_1\cos (2\mathrm{\π}(n+p_2)/N)+B_1\sin (2\mathrm{\π}(n+p_2)/N)+r(n+p_2)+\mathrm{\δ}\left(n\right)\cos (2\mathrm{\π}(n-p_2)/N)\end{array}\right.$ ⑤

Be system of linear equations:

$\left[\begin{array}{ccc}\cos (2\mathrm{\πn}/N)& \sin (2\mathrm{\πn}/N)& \cos (2\mathrm{\πn}/N)\\ \cos (2\mathrm{\π}(n+P_1)/N)& \sin (2\mathrm{\π}(n+p_1)/N)& \cos (2\mathrm{\π}(n-p_1)/N)\\ \cos (2\mathrm{\π}(n+P_2)/N)& \sin (2\mathrm{\π}(n+p_2)/N)& \cos (2\mathrm{\π}(n-p_2)/N)\end{array}\right]\·\left(\begin{array}{c}{A}_1\\ B_1\\ \mathrm{\δ}\left(n\right)\end{array}\right)=\left(\begin{array}{c}{S}_0\left(n\right)-r\left(n\right)\\ S_1\left(n\right)-r(n+p_1)\\ S_2\left(n\right)-r(n+p_2)\end{array}\right)$

According to this system of linear equations, for n=1,2 ..., N, separates the Errors in Radial Rotation Error of Spindle value that above-mentioned three rank systems of linear equations can obtain isolating deviation from circular from and setting-up eccentricity.

More than show and described ultimate principle of the present utility model and principal character and advantage of the present invention.The technician of the industry should understand; the utility model is not restricted to the described embodiments; that in above-described embodiment and instructions, describes just illustrates principle of the present utility model; do not departing under the prerequisite of the utility model spirit and scope; the utility model also has various changes and modifications, and these changes and improvements all fall within the scope of claimed the utility model.The claimed scope of the utility model is defined by appending claims and equivalent thereof.

Claims (3)

1. a spindle rotation error measurement mechanism that is removably installed eccentric, it is characterized in that: comprise displacement transducer installing holder, displacement transducer, grating encoder, signal cable, data acquisition unit, data processor and computing machine, described displacement transducer is installed on described displacement transducer installing holder, described displacement transducer installing holder is installed near main shaft excircle place, between described displacement transducer clamper and main shaft outline, be provided with space, described grating encoder is installed on main shaft sleeve, described grating encoder is all connected with described data processor by described signal cable with described displacement transducer, described data processor is connected with described computing machine.

2. the spindle rotation error measurement mechanism that is removably installed eccentric according to claim 1, is characterized in that: described data processor is comprised of data acquisition unit and signal conditioner.

3. the spindle rotation error measurement mechanism that is removably installed eccentric according to claim 1, is characterized in that: described displacement transducer installing holder is for can install the displacement transducer installing holder of one or three displacement transducer simultaneously.