Patent ID: 8869652

Claim:
A power assisting transmission system of a power assisting bike, comprising: first and second, mutually engaged, gear sets, with the first and second gear sets including a gear and a sliding gear respectively, with at least one of the first and second gear sets comprised of two screw gears; with the gear of the first and second gear sets fixed onto a first transmission shaft, with both ends of the first transmission shaft coupled to a pedal crank and driven by a pedaling force, with the gear of the second gear set having a male end of a concave and convex connector disposed on an axial end, with the sliding gear of the first and second gear sets installed on a second transmission shaft and engaged and rotated by the corresponding gears of the first and second gear sets on the second transmission shaft to move axially and horizontally, with the sliding gear having a resilience member installed at an axial end; an axial force pad sheathed on a side of the gear of the second gear set and disposed at a backward pedaling displacing end of the sliding gear of the first and second gear sets; an annular magnet sheathed on a side of the sliding gear of the second gear set and displaced synchronously by an external force; a Hall sensor installed at a pedaling displacement end of the annular magnet for detecting a displacement variation of the annular magnet; a ratchet disc, sheathed on a gear edge of the second gear set, and having a chain gear fixed to an edge, with a female end of a concave and convex connector disposed on an internal side and matched with the male end of the concave and convex connector, wherein the ratchet disc is driven to rotate selectively forward and backward by the gear of the second gear set; and a driving motor having a reduction mechanism installed at a front end of an output shaft of the motor and comprised of a plurality of reduction gears, wherein a last reduction gear of the plurality of reduction gears is sheathed on an external side of the ratchet disc.