Abstract: A hub ratchet wheel driving structure includes a central axle having portions respectively received in and coupled to a hub and a ratchet wheel with bearings interfacing therebetween. The hub has an end formed with a diameter-enlarged stepped hole that receives a stop plate to fit therein and is then coupled to a unidirectional grooved ring that is fixed therein through threading engagement. An end of the ratchet wheel is formed with a reduced-diameter stepped shaft that is fit into the diameter-enlarged stepped hole and has a circumferential wall in which horizontal retention troughs are formed for receiving rear ends of the reversal-preventing pawls to disposed therein in a horizontal direction. The ratchet wheel and the reversal-preventing pawls have portions opposite to each other and formed with first and second retention cavities to receive and retain two opposite ends of springs to constrain the reversal-preventing pawls in position.