The layout of the Hitachi excavator's upper structure The upper structure is composed of the main frame, engine, fuel tank, hydraulic oil pressure components, cab, counterweight and other various components, as shown in Figure 2-27.
After the main frame is welded with steel, it is bolted to the outer race of the rotary bearing. The engine, hydraulic components, driver's cab, fuel tank and hydraulic oil tank are installed on the main frame.
The balance weight is bolted to the rear end of the main frame to keep the machine balanced.
The front accessories are assembled on the front end of the main frame.
1. Hydraulic oil tank
The main function of the hydraulic oil tank is to supply hydraulic oil to the main pump and to withstand the oil return from the hydraulic cylinder and motor. In order to prevent the hydraulic oil from being mixed with impurities, the full-flow filter is responsible for filtering impurities and returning oil. The structure of the hydraulic oil tank is shown in Figure 2-28.
2. Fuel tank
The fuel tank is welded to hold engine fuel. The fuel tank prevents the fuel from mixing with impurities. There is a fuel level gauge at the front end of the fuel tank. The fuel level sensor transmits the signal to the fuel level gauge in the cab. The fuel tank structure is shown in Figure 2-29.
