Abstract: Aiming at the unadjustability of the existed rack-pinion inerters, a novel semi-active inerter was proposed based on an adjustable transmission ratio mechanism. The dynamic characteristics of the device were analyzed, and it was proved that the device satisfied the inertial capacitance characteristic and had the function of regulating inertial capacity; the selection of material density, upper and lower bottom radius of the cone cylinder in the design was analyzed. Moreover, a model based on SolidWorks was established. By adjusting the parameters of linear motor and rotary motor, the motion state of rack and flywheel was verified. The influence of these factors on energy storage was explored by changing the position of motor, the material density of cone cylinder and the radius of upper and lower bottom surfaces. The simulation results indicate that the influence of rack drive or linear motor on flywheel movement is greater than that of electric groove, and the transmission ratio of the device can be adjusted online by motor. The material density of conical cylinder and the radius of upper and lower underside have great influence on energy storage of the novel semi-active inerter, while the position adjustment of motor has little influence.

Key words:  semi-active inerter; adjustable transmission ratio; dynamic characteristics; motion simulation model