System Design And Analysis Of Dynamic And Static Characteristics Of High-speed Motorized Spindle

High-speed machining is an advanced manufacturing technology which can be increasing productivity,precision,quality of the product and reducing production costs by raising cutting speed dramatically.High-Speed machine tool is the precondition for realizing high-speed machining.High-speed motorized spindle is a crucial unit of the high-speed.So,it is important to optimize the construction design on improving the performance of the high-speed machine tool by studying the static and dynamic characteristics of High-Speed motorized spindle.In this paper,the types of bearings,the designing of dynamic balance,the calculations of construction parameter are analysed.The cutting force of the spindle,the static stiffness of bearing,the crucial construction parameter of the spindle unit and the critical rotation rate of the spindle unit are calculated which the spindle is at the conditon of the principal parameter.Based on the three-dimensional FEA model,the modal and harmonic response characteristics of the motorized spindle are acquired,and also the naturalfrequency,vibration mode and critical rotation rate are studied.The maximumdynamic displacements of the front,end,rotor and the four bearings site onspindle are studied.Therefore,the construction of the spindle design is proved rational.This paper consists 5 chapters,and the main content is as follows:1 IntroductionFirst of all,this paper gives a simple description for high-speed machining technology and provides the significance of designing high-speed motorized spindle;Secondly,it summarizes the technology of motorized spindle and explains the advantages of selected motorized spindle,at the same time,and analyses the development of domestic and international status of motorized spindle, sums up development direction of the spindle at this stage the in China;again,it gives a simple description on the static and dynamic performance of high-speed motorized spindle and FEA software-ANSYS software;finally,it provides the source of the issue,the main performance and the main content for study of the issue.2 Design of high-speed motorized spindle systemFirst of all,it introduced the requirements of static performance and dynamic performance of the spindle;secondly,it carries out the design of the spindle system,and selects spindle motor,bearing form,bearing lubrication system and the motorized spindle cooling system,and designs two main parameters of the span and interface volume of the motorized spindle,and establishes mechanical model of static stiffness and mathematical model of interface volume of motorized spindle.3 Analysis of static performance of high-speed motorized spindleFirst of all,it analyses and confirms the bearing chosen for this structure is the ceramic bearings angular contact ball bearings;secondly,it studies stress analysis and stiffness calculation of ceramic bearings of high-speed motorized spindle unit under current pre-tightening condition and configuration;finally,it uses FEA software -ANSYS to modal and stimulate for motorized spindle to draw static stiffness of motorized spindle.Among them,two conclusions have been drawn:that is, with the increase of axial pre-tightening force,the contact angle of the bearing will increase dramatically;the radial stiffness of bearing will increase due to pre-tightening force increase.4 Analysis of dynamic performance of high-speed motorized spindleFirst of all,it analyses and confirms that the dynamic performance analysis of spindle unit consists two aspects:that is modal analysis and harmonic analysis;secondly,it carries out ANAYS modeling to analyze the modality of motorized spindle and seeks the solution of the natural frequency and vibration,calculates the critical speed,analyses the effect of bearing pre-tightening force on natural frequency;finally,harmonious analysis for high-speed motorized spindle by ANASYS modeling is carried out and result is summed up.5 ConclusionIt gives the conclusion of the research of this paper and confirms that the motorized spindle designed in this paper can fulfill the designing requirement and it poses presumption for future research on motorized spindle.