Because of the way they specifically operate, hydraulic truck cranes are different from other crane types. Instead of using a winch in order to wind up cables to provide the lifting force, hydraulic cranes use oil instead. Since oil is a fluid that retains its volume, it is incompressible. Therefore, this means it is one of the most ideal types of fluids for pushing pistons towards the direction the force is going to be exerted.
The hydraulic pump creates a pressure that moves the piston. This action is maneuvered by the operator from the controls in his cab. Normally, hydraulic truck cranes use a 2 gear pump.
As 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 that 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: Boom swings have a big roller or ball attached to the carrier. It could swing 360 degrees in both directions. Hydraulic devices control the swing and provide swings at varying speeds in order to rotate 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 alert the operator that maximum weight is approaching.
Pump: The pump's purpose is to steer the outrigger.
Steel Cables: Steel reinforced cables run through the boom and the jib. They can generate up to 6350 kg or 14,000 lbs.
Boom Elevation: The crane's boom ascends with the use of double hydraulic cylinders that are capable of being lowered and raised.
Rotex Gear: The rotex gear is operated by hydraulics and located underneath the cab. It enables the boom to swivel on this gear.