Trailer brake drum is the friction pair of drum brake. It not only needs to have the strength and rigidity required as components, but also requires high and stable friction coefficient, as well as appropriate wear resistance, heat resistance, heat dissipation and heat capacity, etc.

Brake is a component used in the brake system to generate braking force to hinder the movement or movement trend of the vehicle. Except for various deceleration devices, almost all trailer brakes use friction brakes that generate braking torque by the friction between fixed and rotating elements.

Currently, the friction brakes widely used in various trailers can be divided into two categories: drum brakes and disc brakes according to the different rotating elements. The difference between them is that the rotating element in the friction pair of drum brake is the brake drum, and its inner cylindrical surface is the working surface, while the rotating element in the friction pair of disc brake is the disc-shaped brake disc, and its two end surfaces are the working surfaces.

Classification of trailer brake drums

  • The basic shape of the brake drum is drum-shaped, with connection holes in the installation surface.

  • According to different manufacturing methods, the structure of trailer brakes and drums can be mainly divided into the following three types.

Integral casting type

The brake drum is cast as a whole by high-strength gray cast iron or alloy cast iron containing Cr. This kind of brake drum has simple structure, convenient processing and large heat capacity, but the quality is large, and it is mostly used in medium and heavy trailers.

Steel plate and cast iron combination type

The brake drum is composed of a drum disk stamped from steel plate and a cast iron drum ring, which has a small quality and is mostly used in cars and light trailers.

Light alloy and cast iron combination type

The main body of the brake drum is made of light alloy material (such as aluminum alloy, etc.), and is lined with cast iron lining ring. This kind of brake drum not only has small quality, but also has good heat dissipation, and is mostly used in cars.

Design requirements for trailer brake drums

For more informations about trailer accessories, please contact China ZY, we have trailer accessories wholesale at competitive bulk price. If the brake drum is designed improperly, it is easy to deform under heat; if the brake drum is subjected to unbalanced force, it will also produce mechanical deformation, causing poor contact between the brake shoe and the drum, which leads to increased pedal force and stroke; if the runout of the working face of the brake drum is too large, it will also cause self-locking and produce vibration and noise. Therefore, the brake drum should have sufficient wall thickness, and circumferential or axial reinforcement should be cast near the opening on the outer surface to improve the strength. These reinforcements also have the function of heat dissipation, can reduce the temperature of the friction surface, shorten the cooling time of the brake, and increase the energy capacity by 35%~40%.

The working surface of trailer brake drum is usually precision machined after being assembled with the wheel hub, and positioned by the bearing hole. The micro-car requires that the roundness and coaxiality tolerance of the working surface are ≤0.03mm, the radial runout amount is ≤0.05mm, and the static unbalance amount is ≤1.5N·cm.