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

High-speed machining is an modern manufacturing technology which can improve the productivity, precision and quality of products and debase production costs through dramatically raising cutting-speed. And nothing can stop its development. 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 improve the performance of the high-speed machine tool by studying the static and dynamic characteristics of high-speed motorized spindle and optimizing the structure design.The motorized spindle in the high-speed and high-power machining center is studied. And the static and dynamic analysis and the system design are studied with ANSYS software by FEA to improve the capability of the motorized spindle system. First, the system design of the motorized spindle is finished based on the research of the key technologies, such as the choice of bearings, the design of dynamic balance and geometric precision and the static estimate of the motorized spindle structure parameters; The structure characteristics of the high-speed motorized spindle is also studied, and two key parameters including the span between the two pairs of bearings and the use level between motor rotor and the shaft which is important to design the motorized spindle are analyzed in detail. Secondly, a FEM modeling of the motorized spindle is established used the ANSYS software, thus calculating the static rigidity of motorized spindle, and at the same time the influence of preload on the static rigidity of motorized spindle is also studied in detail; the simple methods of calculating the static rigidity of bearings is achieved through the structure modeling and the mechanical property analysis of angular-contact ball bearing based on Hertz Contact Law, and the influence of preloading on the contact angle and rigidity of the chinaware bearings is studied. Finally, two-dimensional and three-dimensional FEA model of the motorized spindle are built up with ANSYS to achieve the static rigidity, modality harmonic response characteristics of the motorized spindle; and the natural frequency, vibration mode and critical rotation rate are also studied;, the maximum dynamic displacements of the front-end, the rear-end, the middle of rotor and the four bearings site on motorized spindle with the high-speed are studied, thus validating the rationality of the motorized spindle structure design.