| 摘要 |
PURPOSE:To prevent the resonant oscillation of a brake drum when a brake is applied and to reduce a brake noise by making the width of fins nonuniform in the peripheral direction of the brake drum in the brake drum protruded with cooling fins in the radial direction of the outer periphery. CONSTITUTION:Cooling fins 13 protruding in the radial direction and forming lugs in the peripheral direction are provided in one body on the outer periphery of the cylinder of a brake drum 3. Each fin 13 is formed uniform in its distance (p) and height (h), but on the other hand nonuniform in its width t1, t2, i.e., its thickness in the rotating axis direction of the brake drum 3 is varied at every suitable length in the peripheral direction. Accordingly, the resonant oscillation of the brake drum 3 due to the friction with a brake shoe when a brake is applied is prevented and a brake noise is reduced. In addition, if appropriate recesses 3c, 3d are formed on side edges 3a, 3b of both side brake drums, the reduction effect of a brake noise can be improved. |
