Clearance Measurement Equipment for Gas Lubricated Dynamic Pressure Bearing of Gyro Motor
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Abstract
The clearance of gas lubricated dynamic pressure bearing of gyro motor refers specifically to small internal air gap between the rotor and stator. The clearance size is an important indicator of running performance of a motor. In this work, a dedicated clearance measurement equipment is developed. The clearance is converted to external micro displacement and measured by dual inductive probes with relative measurement principle. For this purpose, three main functional modules are designed together with corresponding electronic and pneumatic control systems. The clamp fixation module helps to support the measured bearing flexibly at the shaft end, which is conducive to protect the bearing and ensure the smoothness of force application. The force application module consists of a 3-D precision motion platform and a triaxial force sensor. It converts internal air gap to external micro displacement in cooperation with the clamp fixation module. The displacement measurement module is a 2-D precision motion platform carrying dual inductive probes. Based on theoretical analysis and practical experiments, the measurement accuracy is superior to 0.3 μm. Moreover, it realizes controllable and continuous force application, which is suitable for batch measurement.
Keywords
Clearance Displacement measurement Dynamic pressure bearing Force application Gyro motorList of symbols
- F1
Threshold contact force for measurement
- F2
Threshold contact force for centering alignment
- εc
Total centering alignment error
- εrc
Error of radial clearance measurement caused by center alignment error
- ΔR
Radius difference between the ball and spherical bowl of bearing
- εrc′
Derivation of εrc with respect to |ΔR|
- εac
Error of axial clearance measurement caused by center alignment error
- Δa
Actual axial clearance
- Δr
Actual radial clearance
- Δam
Measured axial clearance
- Δrm
Measured radial clearance
- εrd
Error of radial clearance caused by deflection
- εad
Error of axial clearance caused by deflection
- α
Deflection angle of measured bearing in vertical plane
- β
Deflection angle of measured bearing in horizontal plane
Notes
Acknowledgements
This research work was supported by National Science and Technology Major Project of China (Grant No. 2013ZX04001091), Major Project of Basic Scientific Research of Chinese Ministry (Grant No. JCYK 2016 205 A003), and the National Natural Science Foundation of China (Grant No. 51621064).
References
- 1.Dellacorte, C., & Valco, M. J. (2000). Load capacity estimation of foil air journal bearings for oil-free turbomachinery applications. Tribology Transactions,43(4), 795–801.CrossRefGoogle Scholar
- 2.Dellacorte, C., Radil, K. C., Bruckner, R. J., & Howard, S. A. (2008). Design, fabrication, and performance of open source generation I and II compliant hydrodynamic gas foil bearings. Tribology Transactions,51(3), 254–264.CrossRefGoogle Scholar
- 3.Chen, G., Yang, Y., Ma, R., & Chen, B. (2015). Modeling cone self-acting gas lubrication bearing dynamics. Procedia Engineering,126, 416–420.CrossRefGoogle Scholar
- 4.Lai, T., Chen, S., Ma, B., Zheng, Y., & Hou, Y. (2014). Effects of bearing clearance and supporting stiffness on performances of rotor-bearing system with multi-decked protuberant gas foil journal bearing. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology,228(7), 780–788.CrossRefGoogle Scholar
- 5.Chen, Y. S., Chiu, C. C., & Cheng, Y. D. (2010). Influences of operational conditions and geometric parameters on the stiffness of aerostatic journal bearings. Precision Engineering,34(4), 722–734.CrossRefGoogle Scholar
- 6.Radil, K. C., Howard, S. A., & Dykas, B. (2002). The role of radial clearance on the performance of foil air bearings. Tribology Transactions,45(4), 485–490.CrossRefGoogle Scholar
- 7.Radil, K. C. (2003). Radial Clearance Found To Play a Key Role in the Performance of Compliant Foil Air Bearings. Technical Report, NASA, NASA/TM-2003-211990.Google Scholar
- 8.Dal, A. & Karacay, T. (2014). Dynamics of externally pressurized air bearing with high values of clearance. In Proceedings of ASME 2014 12th biennial conference on engineering systems design and analysis, 2, 2014.Google Scholar
- 9.Meier, N. & Georgiadis, A. (2016). Automatic assembling of bearings including clearance measurement. In Proceedings of the 48th CIRP conference on manufacturing systems (pp. 242–246).Google Scholar
- 10.Chen, Y. X., & Yang, S. N. (2005). Dynamic measurement of bearing radial clearances. Key Engineering Materials,295–296, 361–366.CrossRefGoogle Scholar
- 11.Papadopoulos, C. A., Nikolakopoulos, P. G., & Gounaris, G. D. (2008). Identification of clearances and stability analysis for a rotor-journal bearing system. Mechanism and Machine Theory,43(4), 411–426.CrossRefGoogle Scholar
- 12.Jiao, J., Zhang, Q., Wu, B. & He, C. (2008). Measurement of lubricant film thickness using incidence ultrasound. In Proceedings of IEEE international ultrasonics symposium (pp. 836–839).Google Scholar
- 13.Xiao, Y., Chen, Z. & Zhang, Li. (2009). System design and experimental research on tip clearance measurement of aero-engines by digital radiograph. In Proceedings of the ninth international conference on electronic measurement and instruments (pp. 2271–2274).Google Scholar
- 14.Tomassini, R., Rossi, G., & Brouckaert, J.-F. (2016). On the development of a magnetoresistive sensor for blade tip timing and blade tip clearance measurement systems. Review of Scientific Instruments,87(10), 102505.CrossRefGoogle Scholar
- 15.Addabbo, T., Bertocci, F., Fort, A., Mugnaini, M., Panzardi, E., Vignoli, V., et al. (2018). A clearance measurement system based on on-component multilayer tri-axial capacitive probe. Measurement,124, 575–581.CrossRefGoogle Scholar
- 16.Podhraški, M., & Trontelj, J. (2016). A differential monolithically integrated inductive linear displacement measurement microsystem. Sensors,16(3), 384.CrossRefGoogle Scholar
- 17.Ibaraki, S., Kitagawa, Y., Kimura, Y., & Nishikawa, S. (2017). On the limitation of dual-view triangulation in reducing the measurement error induced by the speckle noise in scanning operations. International Journal of Advanced Manufacturing Technology,88(1–4), 731–737.CrossRefGoogle Scholar
- 18.Wei, P., Lu, X., Qiao, D., Zou, L., Huang, X., Tan, J., et al. (2018). Two-dimensional displacement measurement based on two parallel gratings. Review of Scientific Instruments,89(6), 065105.CrossRefGoogle Scholar