Design and kinematic analysis of a novel decoupled 3D ultrasonic elliptical vibration assisted cutting mechanism.

The 3D elliptical vibration-assisted cutting (EVC) mechanism with arbitrary elliptical locus in space has a wide array of industrial applications for generating micro/nano-structured surface. However, the current 3D EVC mechanism are limited by their motion couplings, resonant frequencies and regulation of arbitrary elliptical locus. In order to improve the output properties, an innovative decoupled 3D ultrasonic EVC mechanism is proposed in the form of compliant parallel mechanism. First, the proposed 3D ultrasonic EVC mechanism is specifically designed to be capable of generating uniformly magnified output displacement in three directions and its 3D elliptical locus is obtained by the designed multi-axis flexure hinge structure with three orthogonal sub chains. Design process of multi-axis flexure hinge structure is respectively described from displacement amplification and decoupling output. The kinematics and amplification ratios of the designed 3D EVC mechanism are analytically modeled and a finite element analysis is performed to validate the designed 3D EVC mechanism. Based on the analysis results, a prototype device is fabricated, and then its vibration characteristics are evaluated by using the established test system. The test experiments show that the performance of the developed 3D ultrasonic EVC mechanism is satisfied.