Design, analysis and experiment of a compliant displacement amplification mechanism with large amplification ratio

The bridge-type mechanism is highly valued as a displacement amplifier in precision engineering due to its compact and symmetrical design. Nonetheless, it suffers from a drawback of limited magnification, which hampers its broader application. To overcome this limitation, this paper proposes a compliant displacement amplification mechanism that integrates two bridge-type mechanisms with a lever-type mechanism. This novel design not only retains a compact and symmetrical structure but also achieves a large amplification ratio and a high natural frequency, surpassing traditional designs. The static and dynamic models of the amplification mechanism are derived using the compliance matrix method and the Lagrangian method, respectively. Theoretical calculations indicate that the mechanism has an amplification ratio of 50.1 and a first-order natural frequency of 132.5 Hz. Finite element simulation analysis shows that the displacement amplification ratio and first-order natural frequency of the mechanism are 47.4 and 128.69 Hz, respectively. The mechanism is experimentally tested, and the experimental results show that the displacement amplification ratio is 43.9 and the first-order natural frequency is 119.34 Hz. The relative error between the experimental result and the simulation result of the amplification ratio is 7.97%, and the relative error between the experimental result and the simulation result of the first-order natural frequency is 7.83%, which meets the design requirements.