Design requirements of brake drum:
Improper design of brake drum, changeability when being heated; The force imbalance of the brake drum can also produce mechanical deformation, making the foot and the drum contact is not good, resulting in increased pedal force and stroke; When the roundness of brake drum is too large, it will cause self-locking and generate vibration and noise. Therefore, the brake drum should have sufficient wall thickness and cast circumferential or axial reinforcing bars near the external surface to the open part to improve the strength. These reinforcing bars can reduce friction surface temperature, shorten brake cooling time and increase energy capacity by 35%~40%.
The brake drum working face is usually assembled with the wheel hub, and the bearing hole is positioned for finishing. The minicar requires the roundness and coaxiality tolerance of the working face to be less than or equal to 0.03mm, radial runout to be less than or equal to 0.05mm, and static inequality to be less than or equal to 1.5n ·cm.