A method for modeling rigidity of a transmission chain of a double lead screw drive
system includes as the steps of calculating the rigidity of a rolling
joint surface, analyzing the contact rigiditycause by
friction force of lead screw, calculating the rigidity of
fixed joint surface, modeling the dynamics of double lead screw, and calculating the rigidity of drive chain of double lead screw, etc, wherein the rolling
joint surface comprises a lead screw-nut
joint surface and a bearing joint surface, the fixed bonding surface includes a
workbench-slide block joint surface, and the contact stiffness of the rolling joint is calculated by using the
Hertz contact theory; establishing a friction model and taking into account the stiffness change of the joint surface caused by the
friction force of the lead screw; considering the
coupling effect of the worktable, establishing an accurate rigidity
chain model of the double screw drive
system by using the centralized
mass method, thereby improving the dynamic modeling accuracy of the double screw drive
system and the asynchronous error of the double-drive feed and improving the positioning accuracy of the double-drive
machine tool. The method solves the problem that the rigidity of the joint surface is ignored in the dynamics modeling of a conventional double-screw drive system, and the model accuracy is low.