Abstract: A micro rotary mechanism with single degree of freedom symmetric drive as well as guiding and transformation is designed based on drive and guiding principles of flexible hinges, which is able to make linear motion transform into accurate rotary motion. The micro rotary mechanism is symmetric to center. The flexible hinges are used to guide the micro linear motion of piezoelectric actuator, which can transform the linear motion into rotary motion and balance the horizontal force and moment during transformation motion. The kinematics of the mechanism is analyzed based on establishing the kinematics model of the mechanism, and the function relationship between linear motion input Δu and rotary motion output Δθ of the mechanism is discussed. The simulation to the performance of mechanism transformation is given by the finite element method. The performance of the mechanism motion is tested the experiment, the error between the experimental results and mechanism kinematics analysis is 8.0%, the error between the experimental results and the finite element analysis is 6.2%. The experiment results show that motion of the mechanism is smooth and well in linearity, the lowest linearity is 0.998. The accuracy and high of linearity is proved by the contrast among kinematics analysis, finite element simulation and experimental. This research has the important application value.

Key words: flexible hinges, linear motion, linearity, micro rotary mechanism, rotary motion