Manufacturing and contact characteristics analysis of internal straight beveloid gear pair

Abstract This paper presents a manufacturing method for straight internal beveloid gear pair by shaper cutter with parallel axes between the cutter and the gear blank. The cutting motions are represented using three degrees of freedom that are the rotation along its axes, translations along the axial and radial directions. With the proposed method, the beveloid gear with a linear or nonlinear variable profile shift coefficient along the tooth width direction can be generated and the tilt deviations by the inclined cutting tool shaft can be avoided. The mathematical description of shaper cutter and the coordinate systems for the cutting procedure were defined. And the mathematical model of external and internal beveloid gears were derived and the loaded tooth contact analysis were conducted. Results show that the teeth mesh in at the toe and mesh out at the heel. The length of the simultaneous contact line on tooth surface increases first and then decreases due to the cone angle. As the load increases, the mesh area, contact pressure, mean value of mesh stiffness and the peak-peak value of angular transmission error are increased due to the elastic deformation. However, the speeds of the increase tendency slow down.