Because of the way they specifically operate, hydraulic truck cranes are different from other crane types. Instead of utilizing a winch in order to wind up cables to provide the lifting force, hydraulic cranes utilize oil instead. As oil is a fluid that retains its volume, it is incompressible. Therefore, this means it is amongst the most ideal types of fluids for pushing pistons towards the direction the force is going to be exerted.
The pressure created by the hydraulic pump moves the piston. This action is maneuvered by the driver using the controls within his cab. Typically, hydraulic truck cranes utilize a 2 gear pump.
Because the actual crane itself is mounted on a truck, it could travel many distances from job to job and there is little dismantling involved. The truck crane has a single engine which controls both the truck and the crane.
Other Components
Boom Telescope: The boom telescope enables the boom to extend or retract because of hydraulics.
Jib: Jibs are latticed structure booms..
Boom Swing: The boom swing is a large ball or roller that is attached to the carrier. It is able to swing 360 degrees in both directions. Hydraulic mechanisms control the swing and provide swings at various speeds in order to revolve the turntable gearbox.
Outrigger: The outrigger is a unit which helps the crane maintain its balance by utilizing hydraulics to lift the truck.
Load Movement Indicator: The load movement indicator is lights that flash so as to warn the operator that maximum weight is approaching.
Pump: The pump is the device responsible for steering the outrigger.
Steel Cables: The steel cables are reinforced and run through the jib and the boom. They can generate up to 6350 kg or 14,000 lbs.
Boom Elevation: The boom of the crane ascends with the use of double hydraulic cylinders which can be raised and lowered.
Rotex Gear: The rotex gear is operated by hydraulics and situated underneath the cab. It allows the boom to swivel on this gear.