This section relates to the area of hydraulic identified as hydrostatics.    In Hydrostatics the Pressure energy of the fluid is converted into mechanical motion.    This differs with the alternative area known as Hydrodynamics which is concerned with the kinetic energy of the fluid.    Hydrostatics is also generally based on oil as the fluid although, in the recent past water was the prime fluid used.    The notes on the linked pages are basic outline notes on the various topics related to the field of hydrostatic motion transmission.   

It is recommended that for production of detail designs or specifications the literature / web pages of relevant suppliers are referenced.    I have tried to include links to a number of these supplers.