Optimization measurement for the ballscrew raceway profile based on optical measuring system

Abstract

Abstract Given that the ballscrew raceway profile directly affects the service characteristics and precision retention of ball screws, this paper proposes an optimized continuous measuring method for the ballscrew raceway profile, without the need to adjust the sensor for the measurement of each raceway. Based on a comparison with existing measuring methods and principles, an optical measuring system is constructed, in which installation errors in the LED sensor and the linear calibration system, together with the straightness of the mobile platform, are obtained and analyzed. More importantly, in this work, we propose a transformation algorithm for the helix angle as well as an arc-selecting principle. Compared to the measurment results and time consumption of the profilometer, the maximum error for the measured radius and contact angle of the system proposed in this paper is 1.5 μm and 35′, and the measuring efficiency is increased by 15.8%, 58.6%, and 67.5% for 1, 5, and 20 continuous raceways, respectively, indicating effective performance in terms of accuracy, repeatability, and efficiency. Moreover, the system is also capable of measuring the pitch diameter and lead error of the ballscrew, which is significant in regard to classifying the accuracy of the ballscrew raceway profile, and improving machining precision.