Knowledge

brake drum knowledge

Brake drum is a drum brake friction coupling member, in addition should have strength and stiffness member as required, there should be as high and stable friction coefficient, and appropriate wear resistance, heat resistance, heat resistance and heat capacity and so on.

Chinese name brake drum Material generally HT200-300 for heat dissipation, meaning increased friction performance drum brake system part

 

The basic shape of the drum brake drum, connecting hole in the mounting surface, as shown in Fig.

Figure 2 brake drum

Figure 2 brake drum

According to different manufacturing methods, the brake drum are the following three types of structures, as shown in FIG.

Figure 3 brake drum classification

Figure 3 brake drum classification

The whole cast of formula

Cast brake drum made of high strength gray cast iron or alloy cast iron containing Cr in a whole. This simple brake drum structure, easy processing, heat capacity, but the larger mass, used for medium and heavy vehicles.

Steel and cast iron composition

Stamped from sheet steel brake drum drum drum plate and cast iron rings two parts one, low mass, and more for cars and light vehicles.

Combined with the light alloy cast iron

Brake drum body of light alloy material (such as aluminum, etc.), the cast iron lined collars. This is not only small brake drum mass, heat is also very good, used car.

Brake drum design requirements

Brake drum poorly designed, when heated volatility; the uneven brake drums, will produce mechanical deformation, shoes and drums to make poor contact, resulting in increased pedal travel and force; drums are not spent round large, self-locking and can also cause vibration and noise. Therefore, the brake drum should have sufficient wall thickness, and the opening portion of the outer surface near the cast circumferential direction or axial ribs to improve strength. These ribs underway cooling effect, can reduce the friction surface temperature, shorten the brake cooling time, the energy capacity increased by 35% to 40%.

Figure 4 brake drum thermal deformation

Figure 4 brake drum thermal deformation

Brake drums are generally in the hub assembly to locate the bearing hole finishing. Miniature car requires face roundness and concentricity tolerances ≤0.03mm, radial runout ≤0.05mm, static unbalance