| Summary: | 碩士 === 元智大學 === 機械工程學系 === 90 === The study focuses on the steady and transient state behaviors for a high speed spindle such as those commonly used in printed circuit board drilling and wafer saw applications. The model of a tapered spindle element is formulated on the flexible dual rotor system as designated in the study. The results comparison based on the theories of the Rayleigh and Timoshenko Beam are also presented respectively. In order to have a general study for the design parameters on the axial symmetrical spindle system, it is included in the tapered spindle elements for transverse inertia, rotary inertia, gyroscopic, bending, shear, axial load, and axial torque effects.
The derived theoretical equations are formulated into a finite element code with modular and parametric design for the study of the rotor dynamic system. For the verification of the code, a commercial finite element software ANSYS is used to simulate a uniform rotor and compare the results by setting equal diameter from the developed code for the general tapered rotor. The differences are within 1% in the frequency domain results. However, some of the flexibility and parametric study features are unique for the code if compared with ANSYS.
Numerical results show that: increase of the pulling tool force, angular acceleration and boundary stiffness can reduce system response amplitude during the acceleration process. Changing the tapered angle at tool end will affect the spindle response amplitude only when system approaches the 5th critical speed. Furthermore, the system’s steady and transient behavior was not affected by the low shear coefficient of the shafts. Due to the flexibility of the developed code which covers all the potential parameter changes in the spindle design, it is believed that the code can be used as an effective tool in the design and dynamic analysis of a high speed spindle system.
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