Design And Experimental Research Of Small Hybrid Vibration Spindle

With the rapid development of scientific technology and industrial production, a variety of new materials and processing methods are used more and more widely in product development, which lead to emergence of vibration cutting. It is meaningful to combine the excitation device and machine-tool spindle, according to the practical needs of equipment of vibration cutting. As a result of the vibration force of machine-tool spindle, rolling bearings subject to more prominent alternating stress in the situation of external vibration, which reduce the life of the rolling bearings. When the spindle diameter is less than 60 mm, the spindle speed must be increased in order to ensure cutting speed, which also increases the consumption of the bearing. The traditional hydraulic excitation equipment is limited by frequency width of servo valve, which is difficult to achieve a higher frequency. Therefore, the research on hybrid spindle adapting to high frequency vibration and applying to vibration cutting has a very important value.This paper designs a small hybrid vibration spindle that supported by hybrid bearing. The oil cavity structure of the hybrid bearing is spiral. Use two degrees of freedom valve(2D excitation valve) as a control element of hybrid vibration spindle, which improves excitation frequency of hydraulic vibration device. 2D excitation valve controls the oil in and out of the hydraulic actuators(small hybrid spindle) alternately, Which driving the spindle axially reciprocate. The main work and achievements of this paper are as follows:1. Design of small hybrid vibration spindle. Structure and working principle 2D excitation valve and hybrid spindle is elaborated. And vibration control principle is analyzed. Then focuses on the design of hybrid bearing structure, including design calculations of the hybrid bearing, selection of materials, choice of spindle and the spindle motor.2. Mathematical model building of small hybrid spindle. The mathematical model of excitation spindle is established based on classical hydraulic equations. the equation of hybrid bearing, which include the pressure of oil film and capacity equation is established based on the theory of classical static pressure and dynamic pressure bearing.3. Finite element simulation of hybrid bearing. Oil film of hybrid bearing is simulated to analyze the impact of simulation parameters on the oil film pressure distribution and bearing capacity size on Fluent software modules in ANSYS Workbench.4. Experimental research of Small Hybrid vibration spindle. Experimental platform is built to collect the date of vibration chamber pressure, vibration displacement, vibration acceleration, leakage flow and radial displacement of the spindle between 20 Hz and 800 Hz of the excitation frequency, and analyze them. And then testing different spindle rotating speed and oil pressure of hybrid effect on the spindle radial displacement. Finally, analyze the spindle rotation accuracy.