Flexibility Analysis and Experimental Design of Dual-Chamber Bellows Isolator for Low-Frequency Damping Performance

To achieve an effective and versatile solution for reducing vibrations and reducing maintenance costs, the dual-chamber flexible bellows isolator (D-CFBI) of rubber material is designed. The outer chamber of D-CFBI is used as an actuator to change its own variable stiffness and control the feedback force by filling negative pressure gas. The inner chamber is used as a rubber air spring to work as the main vibration isolation element. Under different loads and sinusoidal excitation forces, the damping characteristics and damping effects of the D-CFBI with different stiffness are investigated. By exciting the isolator, the frequency sweep experiment is carried out, the dynamic flexibility in the initial state is studied, and a preload of the D-CFBI is given to change the stiffness of the D-CFBI, and the changing trend between restoring force and amplitude and frequency is found out. Conclusions can be summarized that increasing the preload of the D-CFBI leads to increased stiffness and better damping effect. For compression amounts of 20% and frequencies higher than 7Hz or amplitudes lower than 2mm, the damping effect is also better. Consequently, this D-CFBI offers satisfactory damping and increased safety at low amplitudes and frequencies. To achieve optimal damping, it is recommended to adjust the stiffness of the driver.