What is an excavator composed of?

  
  An excavator consists of five parts: a working device, a rotary mechanism, a power device, a walking mechanism, and auxiliary facilities.
  An excavator, also known as a mining machine, is a earth-moving machinery that uses a bucket to dig materials above or below the bearing surface and load them into transportation vehicles or unload them to a stockyard. An excavator consists of five parts: a working device, a rotary mechanism, a power device, a walking mechanism, and auxiliary facilities.
  The working device is the device that directly accomplishes the excavation task, consisting of a boom, a bucket rod, and a bucket, which are articulated into three parts. The movement of the boom, the expansion and contraction of the bucket rod, and the rotation of the bucket are all controlled by a reciprocating double-acting hydraulic cylinder. In order to meet the needs of various different construction operations, excavators can be equipped with a variety of working devices, such as a front shovel, a back shovel, a drag shovel, a grab, a crane, and a loader, etc.
  The rotary mechanism enables the upper part of the excavator to rotate. It consists of a rotary platform, a rotary bearing, and a rotary drive device. The rotary platform is equipped with a power device, a transmission mechanism, a control device, and a cab. The power device drives the rotary platform to rotate through the rotary drive device.
  The walking mechanism is the supporting part of the excavator, which bears the entire weight and working load of the machine and accomplishes the walking task of the excavator. The walking mechanism includes several types such as a tracked type, a tire type, and a car type.
  The power device is the power source of the excavator, generally using a diesel engine or an electric motor.
Auxiliary facilities are devices on the excavator used to assist in the operation, such as hydraulic manipulation, lubrication, lighting, lifting, and air conditioning.