A general mathematical model for screw-rotor honing using an internal-meshing honing machine

This study proposes a general method to finish screw rotors using internal-meshing honing. During the honing process, the meshing between the screw rotor and the honing wheel is similar to that for a pair of crossed-axis internal-meshing helical gears with few teeth so the machining time can be reduced significantly. A normal rack that conjugates a pair of screw rotors is used to generate the honing wheel. The proposed mathematical model can also be used for screw rotor honing with a variable lead. The topography of the tooth surfaces of a screw rotor with a constant lead and a variable lead are used to show the accuracy and practicability of the proposed mathematical model. A honing wheel with a clearance that is generated using a modified normal rack is used to design the clearance for the male rotor. In addition, influence of additional movements for each machining axis on the tooth modification of screw rotor is investigated and discussed.