Abstract:Taking the no-load four-link mechanism as the research object, the dynamics response of the mechanism is analyzed in terms of the clearance joints position, quantity and lubrication. Among them, the continuous contact force model Lankarani-Nikravesh that considering the energy dissipation is used to calculate the normal collision force in clearance joint. The modified Coulomb friction model is used to calculate the friction force, and the calculation of lubrication force is based on the Sommerfeld lubrication force model that assumes an infinite long pin-bearing. Simulation results show that the clearance joint with different positions has different effects on the dynamics response. The mechanism with two clearance joints has a much greater effect on the system response than that with one clearance joint. However, the lubrication of the clearance joint can stabilize the system vibration and play a good role in buffering. This research can reflect the mechanism dynamics characteristics more realistically, and provide a basis for the analysis of motion precision and mechanism design.