A variable-ratio line gear mechanism

Based on the previous studies of line gear (LG), which is also named as space curve meshing wheel (SCMW) in the published papers, a variable-ratio LG mechanism is proposed in this article. The formulae of contact curves of a variable-ratio LG pair were derived. Then prototypes of variable-ratio LG pairs were designed by these formulae and manufactured by 3D printing. Afterwards, kinematics experiments were conducted by measuring the transmission ratio. The result indicates that a variable transmission ratio is feasible to a variable-ratio LG mechanism designed by these derived formulae, and the change of the transmission ratio is steady according to a prescribed kinematic rule. It is capable of being employed to devices on demand of variable-ratio mechanical transmission mechanism in compact structure.