Ball Screw Threaded Surface Parameters Non-contact Measurement System Design And Analysis

The ball screw is widely used in mechanical industry as transmission function component. The performance of ball screw influences the overall performance of the machine tool directly. The thread profile geometric parameter errors of formed ball screw have great impact on the performance of ball screw, such as position precision, friction torque, use life etc. Studying the parameters measuring system for the thread profile of ball screw has very important theoretical significance and practical application value for making up for the insufficient of current detecting technology, improving the performance of domestic ball screw and shortening the gap with foreign countries.A non-contact measurement method is used in the measuring system to measure the normal profile of ball screw. The measuring stage moves along the axial detection, drove by numerical control system, to drive high precision digital micrometer to collect longitudinal displacement data. And the grating-foot is adopted to collect transverse displacement data. After data pretreatment of the collected outline data, the center and radius of left and right circular arcs are fitted by least square method, as well as the coordinates of ball center. The ball screw thread surface geometric parameters and the errors are calculated, including arc radius, contact angle, pitch error, error in pitch diameter, diameter run-out, shape error and roughness.Based on the software of Visual Basic, measurement system operating software is developed, including parameters setting, data acquisition, data storage, data processing and report printing. Concrete measures are raised to reduce errors and improve the measurement accuracy, after analysis the errors. Different types of the ball screw are chose to do rotating position and repeating measuring experiments. The measuring precision and repeating precision of measuring system are analyzed throng experimental results.The measuring experiments shows that the measurement system can realize continuous uninterrupted measurement, with high precision, high reliability, high stability, simple operation and high automatic degree.