Drill fluid powered hydraulic system

A rotary drill shaft driving system, adapted to be connected to drill pipe providing a source of drill fluid to the system and useful for rotating a drill shaft having a bit connected at one end of the shaft, through the use of drill fluid supplied to said system, comprising:

• a motor driven by hydraulic fluid flowing in only one direction and connected to such shaft means for rotation of such shaft;
• drive means for supplying said hydraulic fluid flowing in said one direction;
• actuation means adapted to receive drill fluid from said source and responsive to flow of said drill fluid for acutating said drive means;
• and
• coordination means responsive to rotation of such shaft for synchronizing flow of drill fluid to said actuation means with supply of hydraulic fluid to said drive means,
• said drive means including:
• first supply means for holding and supplying only a fixed amount of said hydraulic fluid, and
• a first valve actuated by said coordination means for causing said flow of said fixed amount of said hydraulic fluid to be substantially smooth and unidirectional;
• said first supply means being in fluid flow communication with said first valve,
• said actuating means including:
• reciprocating sealed piston means,
• second supply means for receiving and supplying a fixed amount of said drill fluid, said piston means being located between said first and second supply means;
• and
• a second valve actuated by said coordination means and in fluid flow communication with said source of drill fluid and said second supply means, said second valve including an outlet and means for converting such discrete amounts of such drill fluid to a continuous flow of such drill fluid at said outlet.