Down-hole mud motor

Abstract From the Canadian patent

A down-hole hydraulic or mud motor of the type adapted to be connected to the lower end of a drill string and powered by drilling mud for driving a drill bit is described. The down-hole motor is capable of operating at a much slower speed than conventional motors thus enabling the use of conventional drill bits. The motor includes a Venturi system which creates a suction effect on the exhaust fluid thus increasing the effective fluid pressure drop across the working chambers of the motor. The motor also includes improved valving means and is also arranged to prevent large particules of grit and the like from entering the working chambers of the motor. The motor may also include a unique …