Classification of structural characteristics of semi-trailers

     According to structural characteristics, semi-trailers can be classified into variable-wheelbase semi-trailers, semi-trailers with liftable axles, semi-trailers with multiple traction pins, and semi-trailers with movable traction pins. The variable-wheelbase semi-trailer may be a form in which the wheel base moves relative to the semi-trailer frame. The reproduced masses of J10BZ, J15BZ and J140BZ in our country are 7t, 8t and 10t respectively. The longitudinal beams can be stretched and the length of the cargo box can be changed within 7-11m. The axle can lift the semi-trailer. After the axle is lifted, the attachment conditions are changed to reduce driving resistance and tire wear. However, the structure is complicated, and the actuator is pneumatic or hydraulic components. Semi-trailer with multiple traction pins, generally with double traction pins and three traction pins