Analytical and experimental investigation of a high-static-low-dynamic stiffness isolator with cam-roller-spring mechanism

A high-static-low-dynamic stiffness (HSLDS) isolator using cam-roller-spring mechanism with a specially designed cam profile is proposed in this study. The proposed HSLDS isolator is mainly composed of a cam-roller mechanism (negative mechanism) and a vertical spring (positive mechanism). Different from other studies, the cam profile in this paper can be designed specially to accommodate different working requirements. Firstly, the cam design theory is described and a cam whose force-displacement variation is a piecewise linear function is established. After that, the dynamic response of the HSLDS isolator under base excitation is acquired by the Averaging Method, at the same time, the stability and parameters effect of the dynamic system are discussed. Finally, an experimental test system is set up to verify the isolation performance of the HSLDS isolator and its corresponding linear isolator under base excitation. The results show that the HSLDS isolator starts to have isolation effect at 2.36 Hz, while the linear isolator is 3.20 Hz. Meanwhile, the resonance amplitude of the HSLDS isolator is smaller than the linear isolator. The proposed HSLDS isolator could achieve a better vibration isolation performance than the linear isolator, especially in the low-frequency range.