Design and analysis of a dual mass flywheel with continuously variable stiffness based on compensation principle

•The compensation profile line of the DMF is presented.•Continuously variable torque and stiffness properties of the DMF are attained.•The dynamic characteristics of the DMF are analyzed.•The DMF can make the idle speed of the engine to be lower.•The balance mechanism eliminates the inertia force of the compensation device.

A new structure of dual mass flywheel (DMF) with continuously variable stiffness is proposed based on compensation principle in order to release the impact produced by the step changes of stiffness. By theoretical calculation and experiments, the proposed structure and design theory involved are proved to be feasible for reducing the torsional vibration of the power transmission system for automobiles with large-power and high-torque engines. The natural characteristics of the vehicle power transmission system carrying the DMF are analyzed to investigate the influence of torsional stiffness on the first-order and the second-order resonance speeds. The results show that this new DMF can lower the idle speed of the engine, realize high counter torque at a large torsional angle, and avoid the impact due to the abrupt changes of stiffness. An inertia balance mechanism is proposed to eliminate the inertia forces produced by moving parts of the compensation device, which can successfully put the torque compensation theory into engineering practice.