Contact Characters of Rolling Linear Guide Way Pair Under Heavy Load
TIAN Hongliang;YU Yuan;DU Yixian;College of Mechanical and Power Engineering,China Three Gorges University;
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 isunder 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.
【Fund】： 国家自然科学基金资助项目(51775308);; 三峡大学2015级硕士学位论文培优基金资助项目(2017YPY026)
【CateGory Index】： TG659
【CateGory Index】： TG659