Influence of the tilt error motion of the rotation axis on the test of the equivalence principle with a rotating torsion pendulum

2021 ◽  
Vol 92 (3) ◽  
pp. 034503
Author(s):  
Hui-Hui Zhao ◽  
Lu Ding ◽  
Lin Zhu ◽  
Qi Liu ◽  
Wen-Hai Tan ◽  
...  
Keyword(s):  
Equivalence Principle ◽  
Rotation Axis ◽  
Torsion Pendulum ◽  
Tilt Error ◽  
Error Motion

Analysis of error motions of axial locking-prevention hydrostatic spindle

2018 ◽  
Vol 233 (1) ◽  
pp. 3-17
Author(s):  
Penghai Zhang ◽  
Yaolong Chen
Keyword(s):  
Significant Influence ◽  
Harmonic Component ◽  
Necessary Condition ◽  
Third Harmonic ◽  
The Third ◽  
Fourth Harmonic ◽  
Radial Error ◽  
Tilt Error ◽  
Error Motion ◽  
Error Averaging

Hydrostatic spindles are widely used in precision optical grinder and lathe. Their high precision comes from the error averaging effect of oil film. The purpose of this paper is to give the quantitative analysis of the error averaging effect for a newly developed axial locking-prevention hydrostatic spindle. An approximate error motion model of the hydrostatic spindle is established to analyze the internal relationship between the geometric errors of the shaft and the error motions of the spindle including radial, tilt and axial error motions. The theoretical analysis shows that, the roundness errors of the two journals have a major impact on error motions while the coaxiality errors of two journals, the perpendicularity errors of front thrust plate and the coaxiality errors of the land of back thrust bearing, have no significant influences on error motions. The elliptical component of roundness errors of the two journals has significant influence on the axial error motion but no influence on the pure radial and tilt error motions, resulting into the fourth harmonic component of axial error motion. The trilobal component of roundness errors of the two journals has significant influence on the pure radial and tilt error motions but no influence on the axial error motion, resulting in the third harmonic component of pure radial and tilt error motions. The changes of recess pressures are not necessary condition for the error motions. Additionally, the experiment analysis shows that, the third harmonic component is the main part of the measured radial error motion and the third, fourth harmonic components are the main parts of the measured face error motion, which can be reasonably explained by the theory. The model proposed in this paper can be used to guide the precision design and optimization of hydrostatic spindle.

Easy measuring instrument for analyzing the radial and tilt error motions of a rotating shaft

2017 ◽  
Vol 231 (2) ◽  
pp. 667-674 ◽  
Author(s):  
Dong-Hyeok Lee ◽  
Wi-Ro Lee
Keyword(s):  
Real Time ◽  
Measurement System ◽  
Probe Method ◽  
Separation Method ◽  
Rotating Shaft ◽  
Error Separation ◽  
Real Time Measurement ◽  
Rotary Stage ◽  
Tilt Error ◽  
Error Motion

In this study, a real-time measurement system to easily apply multi-probe error separation method for error motion measurement of a shaft was designed and developed. An arrangement condition of sensing probes for accurate multi-probe error separation method was examined and verified by a simulation test. By following the examined arrangement condition for multi-probe method, a measurement system to measure radial and tilt error motions of a shaft was designed and developed. The efficiency of the multi-probe method with the examined arrangement condition was checked by comparing the error motion results for a rotary stage with the error motions in the specifications of the guarantee. It is expected to apply this system to a real-time monitoring system of failure diagnosis for rotating shafts in ships and plants.

Test of the Equivalence Principle with Chiral Masses Using a Rotating Torsion Pendulum

2018 ◽  
Vol 121 (26) ◽  
Author(s):  
Lin Zhu ◽  
Qi Liu ◽  
Hui-Hui Zhao ◽  
Qi-Long Gong ◽  
Shan-Qing Yang ◽  
...  
Keyword(s):  
Equivalence Principle ◽  
Torsion Pendulum

Magnetic effect in the test of the weak equivalence principle using a rotating torsion pendulum

2018 ◽  
Vol 89 (4) ◽  
pp. 044501 ◽  
Author(s):  
Lin Zhu ◽  
Qi Liu ◽  
Hui-Hui Zhao ◽  
Shan-Qing Yang ◽  
Pengshun Luo ◽  
...  
Keyword(s):  
Equivalence Principle ◽  
Magnetic Effect ◽  
Weak Equivalence ◽  
Torsion Pendulum ◽  
Weak Equivalence Principle

Measurement of five-degrees-of-freedom spindle error motion using multi probe error separation

2021 ◽  
pp. 095440542199566
Author(s):  
Sang-Woo Baek ◽  
In-Oh Hwang ◽  
Nahm-Gyoo Cho
Keyword(s):  
Degrees Of Freedom ◽  
Side Surface ◽  
Measuring Method ◽  
Probe Method ◽  
Form Error ◽  
Error Separation ◽  
Tilt Error ◽  
Evaluation Test ◽  
Error Motion ◽  
Fourier Model

Herein, a precision measurement method is proposed to evaluate the radial, axial, and tilt error motions of rotating devices such as precision spindles. To improve the accuracy of the estimated multiple-degree-of-freedom error motion components, form error signals in the runout signals are separated and precompensated for before the calculation of the five-degrees-of-freedom error motion components. Fourier model-based multi probe error separation (MPES) techniques, which can prevent the occurrence of harmonic distortions, are applied to separate the form error signals. A three-probe method is applied to layers on the side surface of the cylindrical artifact, and a modified two-probe method is developed and applied to the upper surface. The radial, tilt, and axial error motions are calculated using the runout signals that do not contain the separated form error signals. The measurement system uses eight capacitive probes to detect the runout signals of the cylindrical artifact mounted at the center of the rotating device. To compare the proposed method with the five-probe-based conventional measuring method, an evaluation test simulation is conducted repeatedly five times. Results indicate that the proposed MPES method calculated the uncertainty using the deviation between the computed results from the existing and novel methods; additionally, the input signal in terms of the radial, tilt (layers 1 and 2), and axial error motions are [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], respectively. It is confirmed that the undesirable effects of the form error signals are successfully removed and that the accuracies of the measured spindle error motion components improve.

Determination of the thermal noise limit in test of weak equivalence principle with a rotating torsion pendulum

2017 ◽  
Vol 26 (9) ◽  
pp. 090401
Author(s):  
Wen-Ze Zhan ◽  
Jie Luo ◽  
Cheng-Gang Shao ◽  
Di Zheng ◽  
Wei-Ming Yin ◽  
...  
Keyword(s):  
Equivalence Principle ◽  
Thermal Noise ◽  
Weak Equivalence ◽  
Torsion Pendulum ◽  
Weak Equivalence Principle ◽  
Noise Limit

The Sun as a Magnetic Star

1976 ◽  
Vol 32 ◽  
pp. 457-463
Author(s):  
John M. Wilcox ◽  
Leif Svalgaard
Keyword(s):  
Recent Work ◽  
Rotation Axis ◽  
Polar Field ◽  
Magnetic Star ◽  
Rotational Axis ◽  
Field Variation ◽  
The Sun ◽  
Arbitrary Angle ◽  
Solar Magnetism ◽  
Oblique Rotator

SummaryThe sun as a magnetic star is described on the basis of recent work on solar magnetism. Observations at an arbitrary angle to the rotation axis would show a 22-year polar field variation and a 25-day equatorial sector variation. The sector variation would be similar to an oblique rotator with an angle of 90° between the magnetic and rotational axis.

Σ =13 tilt grain boundary in silicon bicrystal

1990 ◽  
Vol 48 (4) ◽  
pp. 562-563
Author(s):  
M.J. Kim ◽  
Y.L. Chen ◽  
R.W. Carpenter ◽  
J.C. Barry ◽  
G.H. Schwuttke
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Rotation Axis ◽  
Czochralski Method ◽  
High Resolution Electron Microscopy ◽  
Image Simulation ◽  
Simulation Techniques ◽  
Resolution Electron ◽  
The Common ◽  
Tilt Grain Boundary

The structure of grain boundaries (GBs) in metals, semiconductors and ceramics is of considerable interest because of their influence on physical properties. Progress in understanding the structure of grain boundaries at the atomic level has been made by high resolution electron microscopy (HREM) . In the present study, a Σ=13, (510) <001>-tilt grain boundary in silicon was characterized by HREM in conjunction with digital image processing and computer image simulation techniques.The bicrystals were grown from the melt by the Czochralski method, using preoriented seeds. Specimens for TEM observations were cut from the bicrystals perpendicular to the common rotation axis of pure tilt grain boundary, and were mechanically dimpled and then ion-milled to electron transparency. The degree of misorientation between the common <001> axis of the bicrystal was measured by CBED in a Philips EM 400ST/FEG: it was found to be less than 1 mrad. HREM was performed at 200 kV in an ISI-002B and at 400 kv in a JEM-4000EX.

Sign in / Sign up

Export Citation Format

Share Document