The sliding-rolling mixed motion behavior degrades the ball screw’s precision at different levels.Based on the sliding-rolling mixed motion between ball and screw/nut raceway,the ball screw’s precision loss consider...The sliding-rolling mixed motion behavior degrades the ball screw’s precision at different levels.Based on the sliding-rolling mixed motion between ball and screw/nut raceway,the ball screw’s precision loss considering different given axial loading and rotational speed working conditions was investigated.Since creep and lubrication relate to sliding and rolling motion wear,the creep and lubrication characteristics are analyzed under different working conditions.Besides,the precision loss was calculated considering the sole influence of sliding behavior between ball and screw and compared with the results from other current models.Finally,research on precision loss owing to the sliding-rolling mixed motion behavior was realized under given working conditions,and suitable wear tests were carried out.The analytical results of precision loss are in good agreement with the experimental test conclusions,which is conducive to better predicting the law of precision loss in stable wear period.展开更多
As a key transmission component in computer numerical control(CNC) machine tools,the ball screw mechanism(BSM) is usually investigated under working load conditions. Its accuracy degradation process is relatively long...As a key transmission component in computer numerical control(CNC) machine tools,the ball screw mechanism(BSM) is usually investigated under working load conditions. Its accuracy degradation process is relatively long,which is not conducive to the design and development of new products. In this paper,the normal wear depth of the BSM nut raceway is calculated under the variable speed operation condition using the fractal wear analysis method and the BSM’s accelerated degradation proportional wear model. Parameters of the acceleration degradation model of the double-nut preloaded ball screw pair are calculated based on the physical simulation results. The accelerated degradation test platform of the BSM is designed and manufactured to calculate the raceway wear model when the lubrication condition is broken under the variable-speed inertial load and the boundary lubrication condition under the uniform speed state. Three load forces and two samples are selected for the accelerated degradation test of the BSM. The measured friction torque of the BSM is employed as the evaluation index of the accuracy degradation test. In addition,the life cycle of the accuracy retention is accurately calculated by employing the parameters of the physical simulation model of the BSM. The calculations mentioned above can be used to estimate BSM’s accuracy performance degradation law under normal operating conditions. The application of the proposed model provides a new research method for researching the precision retention of the BSM.展开更多
Ball screw mechanism(BSM)is an important force-motion transfer device which is used in high-precision machine tools such as the computer numerical control.Performance parameters such as contact angle,helix angle,and t...Ball screw mechanism(BSM)is an important force-motion transfer device which is used in high-precision machine tools such as the computer numerical control.Performance parameters such as contact angle,helix angle,and the pitch radius of the screw can greatly affect the transmission precision,and the transmission precision of the BSM are not yet well resolved.In this study,ball contact point motion model is derived to assess the influence of contact angle,helix angle,and the pitch radius of the screw on transmission precision under uniform motion of the BSM.For the purpose of verifying the kinematic characteristics of the contact points between the balls and raceways under a state of uniform motion,a kinematic model is developed and values are computed for a set of boundary conditions.Comparing the simulated data to measured data,the laws of motion for the ball contact points developed in this study are confirmed.Moreover,the effect of the screw velocity on contact angle,helix angle and the pitch radius of the screw directly affects the velocity of the nut.Under the accelerated and uniform motion state of the screw,larger angular velocity of the screw results in an increase in the displacement deviation of the nut,and these parameters of the nut are considered to improve the transmission precision of the BSM.The verification of the research results provides a new research method for the study of the precision retention of ball screw mechanism.展开更多
基金Project(51975012)supported by the National Natural Science Foundation of ChinaProject(Z1511000003150138)supported by the Beijing Nova Program,China+1 种基金Project(Z191100001119010)supported by the Shanghai Sailing Program,ChinaProject(2018ZX04033001-003)supported by the National Science and Technology Major Project,China。
文摘The sliding-rolling mixed motion behavior degrades the ball screw’s precision at different levels.Based on the sliding-rolling mixed motion between ball and screw/nut raceway,the ball screw’s precision loss considering different given axial loading and rotational speed working conditions was investigated.Since creep and lubrication relate to sliding and rolling motion wear,the creep and lubrication characteristics are analyzed under different working conditions.Besides,the precision loss was calculated considering the sole influence of sliding behavior between ball and screw and compared with the results from other current models.Finally,research on precision loss owing to the sliding-rolling mixed motion behavior was realized under given working conditions,and suitable wear tests were carried out.The analytical results of precision loss are in good agreement with the experimental test conclusions,which is conducive to better predicting the law of precision loss in stable wear period.
基金Supported by the National Natural Science Foundation of China(No.51575014,51505020)the Key Foundation Project of China Academy of Railway Sciences(No.2021YJ200).
文摘As a key transmission component in computer numerical control(CNC) machine tools,the ball screw mechanism(BSM) is usually investigated under working load conditions. Its accuracy degradation process is relatively long,which is not conducive to the design and development of new products. In this paper,the normal wear depth of the BSM nut raceway is calculated under the variable speed operation condition using the fractal wear analysis method and the BSM’s accelerated degradation proportional wear model. Parameters of the acceleration degradation model of the double-nut preloaded ball screw pair are calculated based on the physical simulation results. The accelerated degradation test platform of the BSM is designed and manufactured to calculate the raceway wear model when the lubrication condition is broken under the variable-speed inertial load and the boundary lubrication condition under the uniform speed state. Three load forces and two samples are selected for the accelerated degradation test of the BSM. The measured friction torque of the BSM is employed as the evaluation index of the accuracy degradation test. In addition,the life cycle of the accuracy retention is accurately calculated by employing the parameters of the physical simulation model of the BSM. The calculations mentioned above can be used to estimate BSM’s accuracy performance degradation law under normal operating conditions. The application of the proposed model provides a new research method for researching the precision retention of the BSM.
基金the National Natural Science Foundation of China(No.51575014,51505012)Youth Foundation of Standards&Metrology Research Institute(No.BJ2019S01).
文摘Ball screw mechanism(BSM)is an important force-motion transfer device which is used in high-precision machine tools such as the computer numerical control.Performance parameters such as contact angle,helix angle,and the pitch radius of the screw can greatly affect the transmission precision,and the transmission precision of the BSM are not yet well resolved.In this study,ball contact point motion model is derived to assess the influence of contact angle,helix angle,and the pitch radius of the screw on transmission precision under uniform motion of the BSM.For the purpose of verifying the kinematic characteristics of the contact points between the balls and raceways under a state of uniform motion,a kinematic model is developed and values are computed for a set of boundary conditions.Comparing the simulated data to measured data,the laws of motion for the ball contact points developed in this study are confirmed.Moreover,the effect of the screw velocity on contact angle,helix angle and the pitch radius of the screw directly affects the velocity of the nut.Under the accelerated and uniform motion state of the screw,larger angular velocity of the screw results in an increase in the displacement deviation of the nut,and these parameters of the nut are considered to improve the transmission precision of the BSM.The verification of the research results provides a new research method for the study of the precision retention of ball screw mechanism.
