Research On Grinding Precision Of Precision Ball Screw And Its Testing Method

China is a big manufacturing country,but it is controlled by others in terms of core functional components.As the core transmission component of CNC machine tool,precision ball screw directly determines the machining accuracy of CNC machine tool.In order to achieve the goal of a powerful manufacturing country,there is an urgent demand for the manufacturing technology of high-precision,high-quality and high-performance ball screw.The research and development of advanced testing device for the accuracy and performance of the ball screw is an important means and technical guarantee to improve the manufacturing accuracy of the ball screw.This paper intends to develop a dynamic measuring instrument of ball screw pitch error based on precision raster ruler,in order to solve the shortcomings of existing laser pitch dynamic detector,such as poor anti-interference ability,complex operation adjustment and so on.to meet the needs of pitch accuracy testing in the ball screw production site and experimental environment.Firstly,the causes of thread generation and pitch error of ball screw are introduced,and it is pointed out that grinding is the main processing method of high precision ball screw thread,and the grinding process is analyzed in detail.The error sources of ball screw are summarized,and three main error sources are analyzed: the transmission error of machine tool,the pitch error caused by grinding wheel wear and elastic deformation and the error caused by thermal deformation.the corresponding technological measures are given for each kind of error source.Secondly,the commonly used sensors for ball screw pitch dynamic measurement are introduced.According to the design requirements of ball screw pitch dynamic measuring instrument and the commonly used pitch error measurement methods,the corresponding pitch error measurement scheme is designed.The design of the ball screw pitch error measuring instrument is completed,including the design of the main mechanical structure of the measuring instrument,the hardware circuit of the measuring system and the design of the software system.The system adopts parametric and modular design scheme,which can quickly detect the pitch error of different specifications of ball screw.Finally,the testing accuracy and measurement reliability of the measuring instrument are tested and verified.By measuring the ball screws of the same specification produced by different manufacturers for many times,and clamping one of them for many times,the measurement results are compared with those measured on the ball screw laser pitch error measuring instrument.the results show that the measurement accuracy of the ball screw pitch error measuring instrument based on raster ruler can meet the requirements of product accuracy,good repeatability and simple and convenient operation.The work is stable and reliable.