Research On Contact Mechanical Mharacteristics Of External Cylinder Surface In Point Grinding

The surface micro geometry morphology characteristics of the components affect their tribological properties. As a new grinding process technology, it has the characteristics of high efficiency and low wear. Special, its surface micro geometry morphology characteristics of point grinding are different from that of the common cylinder grinding's. Thus the contact and mechanical property of the components grinded by point grinding is different from the component grinded by common cylinder grinding.This paper states the development of the point grinding and the technology properties that are different from the common external grinding are introduced. At the same time, this paper established texture corner ? formula of the components surface in point grinding. The effects of grain direction, contact length of the axis, amplitude of the roughness on the contact mechanical characteristics of the rotary motion pair in the components with different surface morphology characteristics by point grinding are discussed in this paper.For further study of the contact mechanical characteristics in different surface morphology characteristics, two traditional contact model Hertz contact model and statistical theoretical contact model are first summarized. These models cannot be directly used in engineering practice due to their limitations. This paper established the fractal contact mechanical model with grain direction, the contact length of the axis and the amplitude of the roughness based on the fractal theory. By MATLAB programming and changing variable values in sequence, the optimal solution in theory is obtained.For the fractal model of the contact of two cylinder, the theory analysis and the simulation results show that, the introduction of ?c is feasible and the value is bigger when it is internal contact; Compare the contact study on the fractal model with the traditional Hertz theory, the stress in fractal model is larger and when decrease the internal contact gap, it is easy to decrease the contact stress; The contact stress decreases when the radial width of crushing increases with other variables unchanged;Keep the other variables unchanged, the contact length has little influence on the load and stress. The load and contact stress will decline when the relating value of roughness amplitude G increases. The research on the grain angle of the point grinding surface can be divided into big angle and small angle fractal contact model. When the load is constant, the stress of the big angle model decreases with decrease of the grain angle and the small angle model increases with decrease of the grain angle, which can be concluded that there is an angle that leads to the minimum stress. While the big angle model is more suitable in engineering practice, and the grain angle of the point grinding workpiece is smaller than that of the common external surface grinding workpiece, which illustrates a superior mechanical property of the pointing grinding workpiece than that of the common external surface grinding workpiece.