NC Interpolation Grinding and Its Error Influence for Eccentric Hole

Planetary holes which own high position precision are a common structural characteristic of eccentric hole in transmission mechanism. It is difficult to achieve the design requirements through traditional turning and milling process. Based on the spindle condition of NC internal grinder, in the paper the movement interference for grinding eccentric hole was analyzed. And we believe that it is feasible to grinding eccentric hole by interpolation motion of C-axis and X-axis. By considering the influence of constant linear velocity on grinding accuracy, the trajectory equation of C-axis rotation angle and X-axis motion interpolation was established, and the mathematical relationship between the position of the grinding contact point and the motion interpolation of the C-axis and X-axis was determined. According to the results of mathematical analysis, the X-axis positioning accuracy must be higher than the 0.002 mm, and C-axis dividing precision must be higher than \(0.1^{\circ }\) , the micron grade precision accuracy of eccentric hole could be obtained.