为提高小径木单板生产的自动化程度,保证小径木单板双面刨切机整体的生产加工效率,设计了小径木单板双面刨切自动进出料工作台。首先对加工对象及其加工工艺进行分析,确定出原木单板双面刨切的加工工艺流程,制定单板双面刨切机自动进出...为提高小径木单板生产的自动化程度,保证小径木单板双面刨切机整体的生产加工效率,设计了小径木单板双面刨切自动进出料工作台。首先对加工对象及其加工工艺进行分析,确定出原木单板双面刨切的加工工艺流程,制定单板双面刨切机自动进出料台的总体布局方案。其次,对单板双面刨切机自动进出料台主轴进行理论计算,并利用Solid Works 2012软件对其进行结构设计。最后,利用ANSYS分析软件,对单板双面刨切自动进出料台的分料翻板主轴进行静力学分析,根据分析结果对其进行调整,避免单板双面刨切机自动进出料台在工作过程中出现共振危险。结果表明,小径木双面刨切机的小径木单板双面刨切机自动进料工作台的结构设计合理,主轴结构满足强度要求,提高了小径木单板生产的自动化程度,提高了生产效率。展开更多
A motorized spindle supported by active magnetic bearings（AMBs） is generally used for ultra-high-speed machining. Iron loss of radial AMB is very great owing to high rotation speed, and it will cause severe thermal ...A motorized spindle supported by active magnetic bearings（AMBs） is generally used for ultra-high-speed machining. Iron loss of radial AMB is very great owing to high rotation speed, and it will cause severe thermal deformation. The problem is particularly serious on the occasion of large power application, such as all electric aero-engine. In this study, a prototype motorized spindle supported by five degree-of-freedom AMBs is developed. Homopolar and heteropolar AMBs are independently adopted as radial bearings. The influences of the two types of radial AMBs on the dynamic characteristics of the motorized spindle are comparatively investigated by theoretical analysis, test modal analysis and actual operation of the system. The iron loss of the two types of radial AMBs is analyzed by finite element software and verified through run-down experiments of the system. The results show that the structures of AMB have less influence on the dynamic characteristics of the motorized spindle. However, the homopolar structure can effectively reduce the iron loss of the radial AMB and it is useful for improving the overall performance of the motorized spindle.展开更多
This paper has developed a genetic algorithm (GA) optimization approach to search for the optimal locations to install bearings on the motorized spindle shaft to maximize its first-mode natural frequency (FMNF). First...This paper has developed a genetic algorithm (GA) optimization approach to search for the optimal locations to install bearings on the motorized spindle shaft to maximize its first-mode natural frequency (FMNF). First, a finite element method (FEM) dynamic model of the spindle-bearing system is formulated, and by solving the eigenvalue problem derived from the equations of motion, the natural frequencies of the spindle system can be acquired. Next, the mathematical model is built, which includes the objective function to maximize FMNF and the constraints to limit the locations of the bearings with respect to the geometrical boundaries of the segments they located and the spacings between adjacent bearings. Then, the Sequential Decoding Process (SDP) GA is designed to accommodate the dependent characteristics of the constraints in the mathematical model. To verify the proposed SDP-GA optimization approach, a four-bearing installation optimazation problem of an illustrative spindle system is investigated. The results show that the SDP-GA provides well convergence for the optimization searching process. By applying design of experiments and analysis of variance, the optimal values of GA parameters are determined under a certain number restriction in executing the eigenvalue calculation subroutine. A linear regression equation is derived also to estimate necessary calculation efforts with respect to the specific quality of the optimization solution. From the results of this illustrative example, we can conclude that the proposed SDP-GA optimization approach is effective and efficient.展开更多
文摘为提高小径木单板生产的自动化程度,保证小径木单板双面刨切机整体的生产加工效率,设计了小径木单板双面刨切自动进出料工作台。首先对加工对象及其加工工艺进行分析,确定出原木单板双面刨切的加工工艺流程,制定单板双面刨切机自动进出料台的总体布局方案。其次,对单板双面刨切机自动进出料台主轴进行理论计算,并利用Solid Works 2012软件对其进行结构设计。最后,利用ANSYS分析软件,对单板双面刨切自动进出料台的分料翻板主轴进行静力学分析,根据分析结果对其进行调整,避免单板双面刨切机自动进出料台在工作过程中出现共振危险。结果表明,小径木双面刨切机的小径木单板双面刨切机自动进料工作台的结构设计合理,主轴结构满足强度要求,提高了小径木单板生产的自动化程度,提高了生产效率。
基金co-supported by the National Natural Science Foundation of China (No. 51275238)a Project Funded by Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) of China
文摘A motorized spindle supported by active magnetic bearings（AMBs） is generally used for ultra-high-speed machining. Iron loss of radial AMB is very great owing to high rotation speed, and it will cause severe thermal deformation. The problem is particularly serious on the occasion of large power application, such as all electric aero-engine. In this study, a prototype motorized spindle supported by five degree-of-freedom AMBs is developed. Homopolar and heteropolar AMBs are independently adopted as radial bearings. The influences of the two types of radial AMBs on the dynamic characteristics of the motorized spindle are comparatively investigated by theoretical analysis, test modal analysis and actual operation of the system. The iron loss of the two types of radial AMBs is analyzed by finite element software and verified through run-down experiments of the system. The results show that the structures of AMB have less influence on the dynamic characteristics of the motorized spindle. However, the homopolar structure can effectively reduce the iron loss of the radial AMB and it is useful for improving the overall performance of the motorized spindle.
文摘This paper has developed a genetic algorithm (GA) optimization approach to search for the optimal locations to install bearings on the motorized spindle shaft to maximize its first-mode natural frequency (FMNF). First, a finite element method (FEM) dynamic model of the spindle-bearing system is formulated, and by solving the eigenvalue problem derived from the equations of motion, the natural frequencies of the spindle system can be acquired. Next, the mathematical model is built, which includes the objective function to maximize FMNF and the constraints to limit the locations of the bearings with respect to the geometrical boundaries of the segments they located and the spacings between adjacent bearings. Then, the Sequential Decoding Process (SDP) GA is designed to accommodate the dependent characteristics of the constraints in the mathematical model. To verify the proposed SDP-GA optimization approach, a four-bearing installation optimazation problem of an illustrative spindle system is investigated. The results show that the SDP-GA provides well convergence for the optimization searching process. By applying design of experiments and analysis of variance, the optimal values of GA parameters are determined under a certain number restriction in executing the eigenvalue calculation subroutine. A linear regression equation is derived also to estimate necessary calculation efforts with respect to the specific quality of the optimization solution. From the results of this illustrative example, we can conclude that the proposed SDP-GA optimization approach is effective and efficient.
