Patent ID: 6979246

Claim:
A central speed control mechanism for remote control cars comprising: a housing and a cover connectable to the housing, the housing having an inner wall provided with grooves, a tooth rim provided on a rim of the cover, two pivots each provided with a helical gear at an end and passing through both of the housing and the cover; and a gear set including a positioning block, a plurality of bevel gears and axles, axle holes being equally provided on a periphery of the positioning block for the axles to engage and position therein, a central hole with a cone surface being provided in the bevel gears, a front end of the axles being provided with a positioning pillar which forms a cone surface by degree, a rear end of the axles being in the form of the same shape as each of the grooves on the inner wall of the housing for engagement purposes, expanding stairs being provided in the central hole of the bevel gears of the gear set for receiving an O-ring therein, such that when the bevel gears are drawn back due to centrifugal force, the O-ring will be pressed to generate a restoring force; whereby when the axles are inserted into the central hole of the bevel gears, the axles are assembled to the periphery of the positioning block; and after assembling the gear set into the housing and connecting the cover with the housing as a whole, the helical gear at the end of the pivots will engage with the bevel gears; when the speed control mechanism rotates, the cone surface of the central hole of the bevel gears will match with the cone surface of the axles; and under centrifugal force generated by the bevel gears of the gear set, the bevel gears would be drawn back to form a cone-engagement stopping force along an axis direction of the axles, thereby generating a damping force.