A drum brake can be a brake that uses friction attributable to a set of sneakers or pads that click outward against a revolving cylinder-shaped part called a brake drum.
The term drum brake commonly means a brake in which shoes press on the inner surface of the drum. When shoes press on the exterior of the drum, it will always be called a clasp brake. The location where the drum is pinched in between two shoes, similar to some conventional disc brake, its sometimes called a little drum brake, though such brakes are relatively exceptional. A related type named a band brake uses a flexible belt or "band" wrapping round the outside of a drum.
The backing plate provides a base to the other components. The back plate also boosts the rigidity of whole set-up, supports the housing, and protects it via foreign materials like dust and other road debris. It absorbs the torque through the braking action, and this is why back plate is also known as the "Torque Plate". Since all braking operations exert pressure about the backing plate, it need to be strong and wear-resistant. Levers pertaining to emergency or parking brakes, and automatic brake-shoe adjuster were also added in recent years.
The brake drum is generally made of a special sort of cast iron that will be heat-conductive and wear-resistant. It rotates considering the wheel and axle. Every time a driver applies the brakes, the lining pushes radially resistant to the inner surface of the drum, and the ensuing chaffing slows or stops rotation belonging to the wheel and axle, in so doing the vehicle. This chaffing generates substantial heat. On this design, one of this brake shoes always things the self-applying effect, regardless if the vehicle is going forwards or backwards.  This is particularly useful on that rear brakes, where the parking brake (handbrake or footbrake) must exert enough force to quit the vehicle from journeying backwards and hold it with a slope. Provided the contact section of the brake shoes is definitely large enough, which isn't always the case, the self-applying effect can securely hold a car or truck when the weight is transferred into the rear brakes due to the incline of a downward slope or the reverse direction of motion. A further advantage of having a single hydraulic cylinder on the rear is the opposite pivot may be made as a double-lobed cam that is certainly rotated by the action belonging to the parking brake system.