Nonlinear dynamics modeling and analysis of aviation drilling actuator feed system considering assembly error

Abstract

The superior dynamic performance and machining accuracy of the aviation drilling actuator are crucial for high-quality drilling of aviation structural components. It is essential to construct a dynamic model that accurately predicts the dynamic characteristics of the actuator. However, the modeling rarely considers the influence of assembly errors, which makes it difficult to ensure the model precision. In this work, the nonlinear force of the joint surface between the ball screw (BS), rolling bearings and ball linear guide (LG) was derived, taking into account the moving and rotation errors of the guide rail (GR) and the misalignment errors of the bearings. A dynamic model with six degree-of-freedom (DOF) was established for the aviation drilling actuator. The Runge-Kutta method was selected to solve the model, and the model accuracy was verified by experiments. The influence of various assembly errors and worktable feed position on the vibration response of the aviation drilling actuator in three directions was analyzed by the time history, frequency spectrum, phase diagram, and amplitude-frequency curve. The research results indicate that variations in assembly errors and feed position affect the dynamic properties of the system. The moving errors along the horizontal and vertical directions and the rotation errors around the horizontal and vertical directions of the GR notably affect the amplitude-frequency characteristics and vibration displacement of the two directions. The bearing misalignment error in the horizontal plane significantly affects the axial vibration of the drilling actuator. The maximum vibration response in the three directions is achieved when the feed position is in the middle of the BS. Therefore, dynamic model analysis can provide theoretical guidance for adjusting assembly errors and selecting reasonable machining positions to improve the stability and machining accuracy of aviation drilling actuator.