Influences of circular runout errors and processing parameters for slotting on the accuracy of harmonic reducer

Abstract

To investigate the influence of the manufacturing parameters on mesh behaviors for harmonic gear drive, the mathematical model of slotting the circular spline was established using kinematic method based on the tooth profile of the circular spline. Considering the circular runout errors from the machine tool and slotting cutter, the influences of two kinds of circular runout errors on the transmission error for harmonic gear drive were analyzed. Then, the influences of the slotting cutter teeth number and the slotting cycles of the circular spline on the transmission error were discussed. Two circular splines were machined by two types of slotting cutters with different teeth number to verify the theoretical analysis. Results show that the influence of the machine tool's circular runout error on the transmission error is more significant than that of the slotting cutter's circular runout error. For the slotting of the circular spline with one circle, the transmission error is the smallest when the tooth number of the slotting cutter is one third of that of the circular spline. For the slotting of the circular spline with two or three circles, the transmission error is the smallest when the tooth number of the slotting cutter is two thirds of that of the circular spline. However, the transmission error of harmonic gear is the largest when the tooth number of the slotting cutter is half of that of the circular spline.

Keywords

• double-circular-arc tooth profile
• harmonic reducer
• circular spline
• slotting cutter
• transmission error
• circular runout error