A new type of gear pair consisting of a helical non-circular gear and a curve-face gear is designed, which can transmit the time-varying motion of intersected axes of rotation. Based on the generation mechanism of non-circular gear, the geometric model of helical curve-face gear is considered and the generating method of pitch curve of helical curve-face gear is discussed. According to the meshing theory, the meshing equation of helical curve-face gear is built and the mathematical model of tooth surface is developed. The method used to calculate its minimum inner radius and maximum outer radius is obtained. Furthermore, the method that the helical curve-face gear is generated by a shaper cutter is put forward and the three-dimensional model of helical curve-face gear is completed by modeling software. A phenomenon of transmission stability is discovered through contrast to the transmission ratio curve of experimental and theoretical value, which can illustrate the correctness of the design method and the practicability of the helical curve-face gear.
