Chassis mainly has the following system components: 1. driving system (tire, hub, axle bearing, etc.); 2. steering system (steering engine, steering column, pull rod ball head etc.); 3. brake system (brake disc, brake pad, brake pump, brake master pump, ABS pump, wheel speed sensor, brake vacuum pump, etc.); 4. transmission system (transmission assembly, drive shaft, etc.); Suspension system (shock absorber assembly, steering knuckle, suspension arm ball assembly, etc.)