Development Of Performance Testing Device For Ultra-precision Aerostatic Spindle

Ultra-precision aerostatic spindle has the advantages of high precision and speed,low friction,abrasion,heat and pollution,etc.It is an important rotating support component which is widely used in high-speed cutting,PCB drilling,aerospace and other fields.As the precision requirements in the manufacturing field continue to increase,the performance of ultra-precision aerostatic spindles becomes more and more important.However,there is no mature testing standard and convenient device now to provide accurate and reliable test data for the design and development of aerostatic spindle.Therefore,this paper proposes an ultra-precision aerostatic spindle performance testing device to achieve performance tests such as vibration,noise,shaft end runout,stiffness and temperature on the measured spindle and provide a basic testing platform for further improving the theoretical research and performance testing of air-floating spindles.The main content and research results of the paper are as follows:(1)Based on the analysis of the performance testing methods and related technologies for ultra-precision aerostatic spindle at home and abroad,the technical scheme of performance testing for ultra-precision aerostatic spindle is proposed: The ultra-precision aerostatic spindle is driven by air compressor,water cooler,dryer and inverter,.The test load is provided by non-contact loading method.The parameters of force,displacement,vibration and temperature are measured by corresponding sensors.The data acquisition and control system are used to collect and process data.(2)The detection device consists of two parts.The first part adopts the air-floating vibration isolation platform,which is equipped with a single-axis ball screw lift,a stepping motor,two limit switches and a clamping device,which are used for clamping,lifting and locking of the aerostatic spindle.The other part adopts T-slot vibration isolation platform,which is equipped with three-axis ball screw lift comes with its driving and locking device to realize the position adjustment of the non-contact loading device,three-dimensional dynamometer,laser displacement sensor,acceleration sensor,infrared thermometer and other test sensors to complete the corresponding data collection of the measured spindle such as force,displacement,vibration,temperature,etc.(3)Based on the advantages of stable and controllable of electromagnetic loading force,an non-contact electromagnetic loading scheme is proposed.Based on the theoretical calculation and performance simulation of the electromagnetic force,an electromagnet designed to meet the experimental requirements is designed.Considering the high speed,low stiffness and non-locking protection of the aerostatic spindle,and to find out the relationship between the excitation current,loading distance,loading plate diameter,rotating speed of spindle and the electromagnetic loading force.An electromagnetic loading experiment device was designed and tested by the method of using a servo motor drives the test shaft and the loading plate.The results show that the Maxwell electromagnetic simulation and the electromagnet experiments verify the correctness of the theoretical calculation.The maximum electromagnetic loading force is 130 N,which can meet the loading demand.The results also show that the electromagnetic loading force is positively correlated with the coil size and current,the diameter of the loading plate,and negatively correlated with the loading distance and the rotational speed.(4)The virtual hardware data acquisition platform was built by NI four-channel universal acquisition card and three-channel sound and vibration acquisition card.Based on LabVIEW software,four test subroutines of conventional performance,vibration,noise and stiffness of the detection device were compiled and integrated.The results show that the data acquisition program can get the collected data,which is convenient for the development of spindle performance testing experiments.(5)Based on the non-contact electromagnetic loading experimental device,experiments of vibration,noise,shaft end runout,stiffness and temperature rise are carried out.The results show that the detection device can perform the test work conveniently and accurately.Through the research of this paper,an ultra-precision aerostatic spindle performance testing device is proposed.The experimental device for non-contact electromagnetic loading of the spindle is designed and built.The relationship between the electromagnetic loading force and excitation current,loading distance,loading plate diameter,rotating speed of spindle are studied.The experiments of vibration,noise,shaft end runout,stiffness and temperature rise of the spindle were tested.The research shows that the proposed non-contact electromagnetic loading experimental device can meet the expected loading requirements,and provides a reference for the non-contact loading test of the ultra-precision aerostatic spindle.