Research On Adjustable Device Based On Piezoelectric Ceramic Of Bearing Preload In Motorized Spindle

High-speed motorized spindle is high-tech product,which includes a number of key technologies,bearing preload is one of the key technologies.The application of bearing preload force has an important impact on the performance of shafting,such as natural frequency,shaft vibration,shaft stiffness and bearing temperature.If the appropriate spindle bearing preload is applied,which can improve the natural frequency,shaft stiffness,reduce shaft vibration.The preload size needs taking into account the low speed high torque and high speed power.Traditional positioning preload and constant pressure preload due to its own shortcomings can not meet the demand.In the article,based grinding motorized spindle in laboratory,around the spindle bearing preload technology and develop bearing preload adjustable device.The main studies as follows:(1)In the article,based on laboratory grinding motorized spindle,theory calculations and finite element analysis of bearing preload is completed.It include:the theoretical calculations of bearing stiffness in different bearing preload,the established shafting simulation model,the impact of different bearing preload to the natural frequencies and harmonic response about shafting.(2)In the article,reference to the study about bearing preload devices at home and abroad,and based on the inherent properties of piezoelectric ceramics,choosing the piezoelectric ceramic as bearing preload force component has been proposed for the first time.The grinding motorized spindle in laboratory is transformed by bearing preload applied to.The pre-tightening device that can adjustable online is designed.(3)The related experiments study of the device designed in the article are finished.It include:the preparation of experimental platform,the set up of experimental platform,validates the bearing preload device whether adjustable,the related experiments of the spindle vibration and bearing temperature under different bearing preload and spindle speed The methods and ideas of studying the appropriate bearing preload appropriate are discussedThrough these studies in the article,determines the impact of the bearing preload to the stiffness of the bearing,shaft natural frequency and shaft harmonic displacement.Choosing the piezoelectric ceramic as bearing preload force component has been proposed for the first time,and makes the appropriate physical,the bearing preload device that can accurately adjust online is really achieved.