Variable-transmission-ratio line gear mechanism

The invention provides a variable-transmission-ratio line gear mechanism. According to the mechanism, a drive wheel and a driven wheel which are provided shafts intersecting at any angle form a transmission pair. Transmission is generated by point contact meshing movement between drive wheel line teeth and driven wheel line teeth. Contact lines of the line teeth are designed according to a space conjugate curve meshing theory. The design equation is divided into an equal-transmission-ratio part and a variable-transmission-ratio part. The equal-transmission-ratio part provides constant speed transmission, and the variable-transmission-ratio part makes the transmission ratios to be in steady transition. The line gear mechanism can provide periodical variable-transmission-ratio transmission, multiple transmission ratios can be provided within the cycle of motion of the driven wheel, and all the transmission ratios can be in steady transition conforming to the motion law.