The main components of a semi-trailer include the frame, superstructure (side panels, gantry frame), kingpin, suspension system (leaf spring/air/single-point/rigid suspension), running gear (axles, wheels, tires), electrical system, support device, protective devices, and trailer accessories.
A detailed description of each semi-trailer component is as follows: The frame is the main load-bearing structure, usually made of T700 high-strength steel; the superstructure includes side panels (used for containing bulk cargo) and a gantry frame (for structural reinforcement); the kingpin is the core component connecting the trailer to the tractor, and must match the fifth wheel height (such as 1329mm in the product specifications); the suspension system includes types such as leaf spring and air suspension, directly affecting the shock absorption effect; the running gear includes axles (such as three-axle/six-axle design), wheels, and tires (specifications such as 12R22.5 or 245/70R17.5); the electrical system covers lighting and brake signal lines; the support device is used to stabilize the trailer when parked; and the protective devices include side guards and a rear bumper.
