Experimental Study On Thermal Deformation Error In Grinding Of Precision Ball Screw

As the key parts of positioning and transmission in CNC machine tools and other precision mechanical equipment,the performance of ball screw affects the manufacturing level of equipment to a great extent.Grinding process is the main method of processing high precision ball screw,due to the uncertainty and randomness of grinding and grinding mechanism of the complexity of make it impossible for us to effectively control the grinding process,how to improve the grinding accuracy of ball screw pitch especially grinding machining accuracy has become a key core technology of the manufacturing sector.Firstly,this thesis introduces the research status and application of ball screw pitch error detection technology and pitch error compensation technology at home and abroad,and summarizes several common ball screw pitch detection and compensation technology.On this basis,the source of screw pitch error in ball screw grinding is analyzed,and the main factors that have great influence on ball screw pitch error in grinding are analyzed.Secondly,the distribution of temperature field and thermal deformation of ball screw in grinding process is obtained by using theoretical analysis and ANSYS finite element method.The temporal and spatial distribution of temperature and thermal deformation on the workpiece under the action of moving heat source is analyzed.Finally,according to the requirement of ball screw pitch precision detection,the screw pitch error detection device based on the on-line detection of machining process is designed.The design method of the whole structure of the device,including the hardware part and the software part,as well as the realized functions are introduced.The overall temperature distribution of ball screw in different processing stages was measured by Ti400 thermal imaging instrument,and the temperature field distribution was compared with that obtained by finite element simulation analysis.At the same time,the pitch error distribution of the ball screw was measured by the pitch error measuring device,and compared with the simulation analysis results of thermal deformation.Then,the pitch error distribution curve of the ball screw was corrected,and a piece-wise compensation method based on the Siemens 840 D numerical control system was proposed.