I would really appreciate if the answer made sense :)
the engine drive,s a hydraulic pump that supply,s hydraulic pressure to the main control valve...that in turn supply,s pressure to the component that the operator select,s ...usually a hydraulic cylinder that control,s a bucket or blade or stabilizer, etc....if you need more detail you can e-mail with specific questions.
No simple answer to this,basically fluid does not compress so when it's pumped into a cylinder is pushes the hydraulic ram outwards or inwards depending on the set up.
The engine (usually a small truck engine of 8 or 9 litres) drives a high volume hydraulic pump which supplies oil under pressure to a set of spool valves which are operated by the driver through a series of levers or in modern equipment by a set of electrical solenoids in the cab.When a valve is opened oil under pressure is fed to one end of a 2 way ram which forces the piston in the ram either in to the ram cylinder or out of it which operates the arm or the bucket.Some track vehicles also have hydraulic motors which are fastened to the track drives to move the vehicle along or they have a simple hydrodynamic gear box and diff as on some large bull dozers.Most have a large heat exchanger to keep the hydraulic fluid cool.
Hydraulic Excavator How It Works
If your asking how to operate,don't be afraid to start pulling and pushing levers slowly to see what lever moves what, every experienced operator has to do this when they get on a new piece of equipment.
