Double-sided collaborative machining for propeller blade based on XYZ-3RPS hybrid kinematic machine

At present, propeller blades are machined single-sided with low efficiency. Thus, a propeller needs to be turned over after completion of the machining of the first side of the blade, which requires second clamping and causes a decline in accuracy. Therefore, a double-sided collaborative machining method for propeller blades is proposed herein. Two XYZ-3RPS hybrid kinematics machines were symmetrically distributed to machine both sides of a propeller blade simultaneously; therefore, the blade could be machined in clamping once, improving the machining efficiency and eliminating the accuracy decline caused by repetitive clamping. Moreover, a supporting device with rigid-flexible switching capability was developed to reduce the cantilever length of the blade, thereby eliminating the substantial deformation and vibration of the blade during the double-sided collaborative machining process to ensure machining accuracy. Additionally, the inverse kinematics formula for XYZ-3RPS hybrid kinematics machines was deduced and the elongation of each drive shaft through the cutter location point and cutter orientation was solved in this study. Thereafter, the decomposition method of the blade shift data was applied to obtain the deformation and vibration amplitude of the blade so that the performance of the double-sided cooperative machining could be quantitatively analyzed. Finally, experiments were conducted on the self-developed prototype, and the results verified the effectiveness of the double-sided collaborative machining method in reducing the deformation and vibration of a blade and improving machining efficiency.