Fu-jia DU, Peng-hui LI. Effect of material expansion coefficient and lubrication on telescope load torque under low temperature[J]. Optics and precision engineering, 2018, 26(3): 616-623.
DOI:
Fu-jia DU, Peng-hui LI. Effect of material expansion coefficient and lubrication on telescope load torque under low temperature[J]. Optics and precision engineering, 2018, 26(3): 616-623. DOI: 10.3788/OPE.20182603.0616.
Effect of material expansion coefficient and lubrication on telescope load torque under low temperature
In order to improve the accuracy of the servo system at low temperature
the mechanism that the load torque of the telescope increase along with the temperature decrease must be deeply understood. Firstly
the influence factors of friction torque of bearing and the influence of low temperature on load torque were analyzed. The lubricant viscosity with temperature variation was studied. The relationship between load torque and grease was tested and discussed. The results indicate that the fluctuation of load torque without the grease at low temperature is decreased and the linearity of load torque is increased. The influence of clearance on bearing friction torque was also analyzed. The expansion coefficient of different materials at different temperatures was measured by resistance strain gauge method. The correlation coefficient between torque and material expansion was established. The result indicates that the load torque at low temperature is 6.67 times load torque at normal temperature
and the maximum of shortening of material reaches 960
μ
ε
. The research on the mechanism of cryogenic load torque in this paper can provide theoretical and experimental data for the precise control of the telescope under extreme environment.
NI F L, LIU H, JIE D Y. GMS friction model identification and compensation based on velocity observer[J]. Electric Machines and Control, 2012, 26(11):70-75. (in Chinese)
FANG Q L, SUN H E, LIU W W. Study on the stribeck curve of slider bearing lubrication state under different load[J]. Journal of Mechanical Transmission, 2016, 40(1):124-126. (in Chinese)
LIAO H B, FAN SH X, HEI M, et al .. Modeling and parameter identification for electro-optical stabilized platform servo systems[J]. Opt. Precision Eng., 2015, 23(2):477-484. (in Chinese)
ZENG D L, XIAO K, LIN ZH CH, et al .. Sub-step identification of LuGre friction parameters of inertially stabilized platform for airborne remote sensing[J]. Opt. Precision Eng., 2015, 24(5):1148-1158. (in Chinese)
LAWRENCE J S, ASHLEY M C B, HENGST S, et al .. The PLATO Dome A site-testing observatory:Power generation and control systems[J]. Review of Scientific Instruments, 2009, 80(6):064501.
DURAND G A, TREMBLIN P, MINIER V, et al .. Antarctic observations at long wavelengths with the IRAIT-ITM Telescope at Dome C[J]. SPIE, 2014:91450D.
ZHANG Y, ZHOU F, YUAN N J. Overview of cryogenic refrigeration technology in space infrared astronomical telescopes[J]. Spacecraft Recovery & Remote Sensing, 2013, 34(5):46-55. (in Chinese)
ZHANG X N, HAN Q K, CHU F L. Research on contact angle of ball bearings based on simplified Jones-Harris method[J]. Journal of Vibration and Shock, 2013, 32(13):170-175. (in Chinese)
FANG B, ZHANG J H, HONG J, et al .. Quick calculation method and contact angle analysis for high-speed angular contact ball bearing under combined loads[J]. Journal of Xi'an Jiaotong University, 2017, 51(6):115-121. (in Chinese)
WEI B, WANG J X, ZHOU G W, et al .. Mixed lubrication analysis of the main supporting angular contact ball bearing of RV reducer[J]. Tribology, 2015, 35(4):454-461. (in Chinese)
IANUS G, DUMITRASCU A C, CȂRLESCU V, et al . . Friction torque in thrust ball bearings grease lubricated[C]. 7th International Conference on Advanced Concepts in Mechanical Engineering, IOP Publishing, 2016: 1-8.
PAN J B, CHENG Y H, ZHU ZH C, et al .. Flow characteristics of grease in circular pipeline at varied temperatures[J]. CIESC Journal, 2014, 65(6):2063-2069. (in Chinese)
SMITH D R, SOUCCAR K. Friction compensation strategies in large telescopes[J]. SPIE, 2010, 7733:77332N.
ZHANG X SH, GUO L, MA M ZH, et al .. Parameter sensitivity of thermal characteristics for micro-expansion type heat switch[J]. Opt. Precision Eng., 2016, 24(7):1633-1639. (in Chinese)