The invention relates to the technical field of lifting machinery accessory devices, in particular to a lifting mechanism of a crane. During usage, timely braking control over a roller is convenient according to the actual lifting position, and the limitation of use is reduced; and a
wire rope is prevented from being disarranged on the roller in the
welding process, the arrangement effect of the
wire rope on the roller is improved, and the use reliability is improve. The lifting mechanism comprises a bottom plate, a left support plate, a right support plate, a lifting motor, a speed
reducer and the roller; the lifting mechanism comprises a connecting shaft, a support shaft, a limiting plate, a connecting spring, a chuck, a cone
brake disc, a fixing plate, a support column, an upper supportsliding column, a lower support column, an angle shift lever, an electric
telescopic cylinder and a U-shape trough frame; and the lifting mechanism further comprises a reciprocating screw, universalrollers, a connecting column, a placement plate, a left supporting plate, a right supporting plate, a guiding shaft, a limiting sliding block, a limiting sliding column and a
transmission belt; the lower side of the right end of the left supporting plate is provided with a left fixing groove; and a left
ball bearing is arranged in the left fixing groove.