Terms Used

Their are many different ways of descibing waterwheels, which are often contradictory and potentially confusing. For clarity rather than using traditional names, those defined by the Cooperative Patents Classification (CPC), a joint enterprise between the American and European Patent Offices, shall be used.


Overshot - any wheel that where the water enters above the axle .


Undershot - any wheel where the water enters below the axle.


Potential Energy (PE) or Gravity Wheel - any wheel where the majority of energy harnessed is PE.


PE Dynamic Wheel - any wheel were PE is converted to KE before entering the wheel.


Kinetic Energy (KE) or Impulse Wheel - any wheel where the majority of energy harnessed is KE.


Bucket Wheel - any wheel where water is caught in a bucket.


Blade - any wheel where an apron or wheel pit is used in conjunction with a blade.


The above terms allow all types of wheel to be described.