摘要
针对空间环境温度在-60~80℃之间交替变化影响航天轴承摩擦力矩的问题,该文利用接触力学和运动学等理论,建立了固体润滑轴承摩擦力矩的数学模型,并分析了内、外圈的摩擦力矩。基于弹性力学、热学和变形协调关系,分析了交变温度影响航天轴承过盈量和预紧力的规律。在此基础上,结合摩擦力矩模型探究了交变温度对航天轴承摩擦力矩的影响机理。通过理论分析研究了交变温度对航天轴承的过盈量、预紧力的影响,进而揭示了交变温度对摩擦力矩的影响规律,并进行了试验验证。研究结果表明:交变温度与内圈过盈量负相关,与外圈过盈量正相关;过盈量增加引起内圈摩擦力矩增大量大于外圈;预紧力随交变温度升高而增大,当交变温度从-60升高到80℃时,与常温时相比预紧力变化范围为-40~40 N;预紧力、环境温度的增加都将引起摩擦力矩增大;摩擦力矩随交变温度增加而增大,随交变温度降低而变小,且摩擦力矩达不到初始时刻的最大值和最小值。研究结果为减缓摩擦力矩变化提供参考。
With the further development of the Beidou navigation satellite network,high precision,high reliability and high security issues of shaft assembly in interstellar link antenna drive unit have been paid more and more attention by the researchers.As the absolutely necessary key components in spacecraft mechanism,the reliability of space bearing is one of the main difficulties in the world’s space technology.Due to the harshness,extremeness and uncertainty of the space environment,the alternating temperature first seriously affects the size and stability of the space bearing friction torque.Secondly,the operation reliability is affected in space bearing while temperature changes.Then,the life,accuracy and reliability of the spacecraft mechanism are affected by the space environment.Space bearing is the sensitive and key problem related to the reliability of spacecraft mechanisms.The reliability of space bearing is the basic guarantee of the normal operation of spacecraft mechanisms,the realization of the intended function and the design life.The friction torque of the bearing reflects the operation of the precision shaft system and will affect the function and accuracy of the shaft system.The improper friction torque of the space bearing will cause the spacecraft mechanism to failure,so the dynamic performance of the friction torque is an important factor to restrict the life and reliability of spacecraft mechanism.Aiming at the space ambient temperature alternating between?60 and 80℃influencing the friction torque issue of space bearing,the mathematical model of friction torque of solid lubricating bearing is established by using contact mechanics and kinematics theory.Then,the friction torque of inner and outer rings is analyzed.Based on the elastic mechanics,thermotics and deformation coordination,the influence law of alternating temperature on the interference and preload force of space bearing is analyzed.On the basis of changing law of the interference and preload force,the influence mechanism of alternating temperature on the friction torque of space bearing is studied by combining the friction torque model.The relationships between the interference and friction torque,the preload force and friction torque,the alternating temperature and the friction torque are investigated by theory and experiment.Meanwhile,the experiment is carried out to verify the theoretical analysis.The results show that the alternating temperature is negatively correlated with the inner ring interference,and the alternating temperature is positively related to the outer ring interference.The increased amount of the friction torque of the inner ring,caused by the increase of the interference,is larger than that of the outer ring.The preload force of space bearing increases with the alternating temperature.Comparing with the preload force at room temperature,the change range of preload force is?40-40 N,while the alternating temperature increases from?60 to 80℃.The increase of preload force or ambient temperature leads to the increase of the friction torque.The friction torque increases with the increase of the alternating temperature,and decreases with the decrease of the alternating temperature.The friction torque cannot reach the maximum and minimum of the initial time.By analyzing the influence law of the alternating temperature on the friction torque of space bearing,the method to reduce or eliminate the influence of the alternating temperature on the friction torque is explored,which provides a theoretical basis for slowing the change of the friction torque.
作者
宁峰平
樊晓琴
陈然
安静涛
赵永生
Ning Fengping;Fan Xiaoqin;Chen Ran;An Jingtao;Zhao Yongsheng(Department of Mechanical Engineering,North University of China,taiyuan 030051,China;China Academy of Space Technology,Aerospace Electromechanical Equipment Institute,Tianjin 300301,China;Parallel Robot and Mechatronic System Laboratory of Hebei Province,Yanshan University,Hebei 066004,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2018年第8期85-92,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家重点基础研究发展计划(973计划)(2013CB733000)
中北大学校基金(XJJ2016003)
关键词
轴承
模型
温度
摩擦力矩
影响机理
装配
bearings
models
temperature
friction torque
influence mechanism
assembly
