Auto-adjust
The gap self-adjusting device is divided into two types: one-time adjustment type and step type. The former device will automatically restore the gap in the brake to the preset value after each braking; the latter device needs to be braked for many times before the accumulation is eliminated when braking or releasing the brake. excess clearance. The excessive clearance of the brake is not entirely caused by the wear of the friction pair, but also includes the thermal expansion of the brake drum and the clearance generated by the elastic deformation of the shoe and the hub. However, the one-time adjustment type clearance self-adjusting device always eliminates the excess clearance according to the actual condition of the brake at that time. If excessive thermal deformation and mechanical deformation happen at this time, the resulting clearance exceeds the set clearance, then in these After the deformation is eliminated, the brakes will drag and even lock. In order to avoid this phenomenon of “over-adjustment”, a step-type self-adjusting device should be used.