The current researches about the rolling linear guide way pair of a CNC machine tool are usually set within the limit of outer force less than the critical force
thus the static characteristic parameters are solved for the case of outer force larger than the critical force. Provided that the carriage and linear guide way transfer the equivalent compressive force to the ball under light load
the ball's compressive deformation is two times the traditional result
hence the stiffness formulas for the case of outer force less than the critical force are improved. The rolling linear guide way pair's stiffness formulas are established considering that the upper ball bears force but no force on the lower ball under heavy load. As a result
the general stiffness formulas are set up for the outer force less than or larger than the critical force. The contact stress and contact deformation between the ball and race are attained through finite element method. Theoretical analysis shows that the upper ball force is an implicit function of the outer force
but the outer force is an explicit function of the upper ball force when the guide way pair is under light load. All static characteristic parameters of the guide way pair are explicit functions of the upper ball force within the whole ranges of light and heavy loads. Simulation shows that: 1)when the outer force is smaller than the critical force
the upper ball force and stiffness increase with the improvement of preload grade; 2)when the outer force is larger than the critical force
the guide way pair's stiffness increases with the increase of outer force
and the upper ball force and stiffness are independent of preload grade; 3)the upper ball force increases with the increase of outer force
and the lower ball force decreases with the increase of outer force or with the reduction of preload grade; and 4)the upper ball stiffness increases and the lower ball stiffness decreases with the increase of outer force. These general stiffness formulas may be applied to the analysis of the contact characteristics of rolling linear guide way pair for CNC machine tools.
MAO Kuanmin, GONG Can, LI Bing, et al. Dynamic modeling research of linear motion ball guide considering surface waviness [J]. Journal of Huazhong University of Science and Technology(Natural Science Edition), 2014, 42(6): 1-5.
MAO Kuanmin, XING Manxi, LI Bin, et al. Dynamic modeling for movable joint of rolling linear guide [J]. Journal of Huazhong University of Science and Technology(Natural Science Edition), 2016, 44(7): 81-85.
WANG Yulin, LI Zuokang, QIU Jinsheng, et al. Device and method for simultaneously measuring comprehensive static stiffness of linear guideway [J]. Journal of Huazhong University of Science and Technology(Natural Science Edition), 2017, 45(9): 58-63.
MA Yali, NING Shichao, QIAN Feng. Natural vibration performance analysis of rolling linear guide [J]. Journal of Huazhong University of Science and Technology(Natural Science Edition), 2016, 44(9): 59-64.
TIAN Hongliang, ZHENG Jinhua, CHEN Tianmin, et al. Normal contact mechanics model of linear motion rolling guideway pair [J]. Journal of Xi'an Jiaotong University, 2016, 50(5): 1-11.
LIU Yao, HUANG Yumei. Theoretical analysis and experimental study on static characteristics of the cylindrical-spherical joint surfaces of linear ball guide on machine tool [J]. Journal of Mechanical Engineering, 2013, 49(21): 25-30.
SUN Wei, KONG Xiangxi, WANG Bo, et al. Contact modeling and analytical solution of contact stiffness by Hertz theory for the linear rolling guide system [J]. Engineering Mechanics, 2013, 30(7): 230-234.
WANG Min, LE Bingbing, PEI Eryang. Contact stiffness modeling and analysis of linear ball guides based on Hertz contact theory [J]. Journal of Beijing University of Technology, 2015, 41(8): 1128-1132, 1150.
KONG Xiangxi, SUN Wei, WANG Bo, et al. Dynamic and stability analysis of the linear guide with time-varying, piecewise-nonlinear stiffness by multi-term incremental harmonic balance method [J]. Elsevier Journal of Sound and Vibration, 2015, 346: 265-283.
SUN Wei, KONG Xiangxi, WANG Bo, et al. Statics modeling and analysis of linear rolling guideway considering rolling balls contact [J]. Proceedings of the Institution of Mechanical Engineers: Part C Journal of Mechanical Engineering Science, 2015, 229(1): 168-179.