the other is to introduce a variety of roles load combination approach. Role of load types are:

Slewing means work or does not work when subjected to various loads role of a work load of the main load, weight load, dynamic load, wind load, etc., in addition to the load gradient, collision load, temperature, load, etc., of the load aim is to understand the role of load types and load sizes convention method, the other is to introduce a variety of roles load combination approach.
Role of load types are:
Work load: the work load of the excavator and bucket digging resistance caused by the weight of material, it is to focus on the form of the lifting mechanism acting on the excavator and the pressing mechanism is transmitted to the supporting means. There loader working load taper roller bearing resistance, resistance and bucket scooping the material and produced by these forces working body and then applied to the supporting device.
Load weight: weight of the machine before the design is generally known, the role of supporting the weight of the device is unknown, it can refer to parameters of the same type and similar machines initially selected seat. Weight distribution according to the structure conditions. Mechanical equipment, electrical equipment, power unit weight is generally seen as a concentrated load, box-type structure weight can be seen as a continuous distribution, truss weight distribution can be assumed in the corresponding nodes.
Wind load: open jobs mining machinery should consider the role of wind load. Wind load calculation that acts in the direction along the first and the force parallel to the ground. Big rain wind load pressure, the machine frontal area and shape and so on.
Dynamic load: including inertial load, vibration and shock loads. When the moving speed and direction changes caused by the mass forces, said inertial forces.