Abstract: A progressive cavity drilling motor is disclosed with a multiplicity of helically formed conduits positioned in a resilient stator. The conduits are placed between an inner wall of a motor casing and a helically formed through hole formed by the stator. The conduits are located in parallel with each of the semi circular lobes thereby reducing the thickness of the elastomer in the lobe area resulting in a reduction of the hysteresis in the elastomer that is caused by cyclic stress reversals of the stator during motor operation. The conduits additionally divert a portion of the drilling fluid through the stator conducting heat therefrom. In addition, one or more of the conduits may be utilized as a communication channel therethrough for measurement while drilling capabilities.

Abstract: A hard facing for teeth on a milled tooth rock bit comprises at least 65% by weight of a mixture of tungsten carbide particles and a balance of steel bonding the carbide particles together and to the cutter cone of the rock bit. The tungsten carbide particle mixture comprises from 35% to 80%, and preferably from 65% to 80%, by weight 20 to 30 mesh cemented tungsten carbide, and from 20% to 65%, and preferably from 20% to 35% by weight 40 to 80 mesh single crystal monotungsten carbide.

Abstract: A hard facing for teeth on a milled tooth rock bit comprises at least 65% by weight of a mixture of tungsten carbide particles and a balance of steel bonding the carbide particles together and to the cutter cone of the rock bit. The tungsten carbide particle mixture comprises from 35% to 80%, and preferably from 65% to 80%, by weight 20 to 30 mesh cemented tungsten carbide, and from 20% to 65%, and preferably from 20% to 35% by weight 40 to 89 mesh single crystal monotungsten carbide.

Abstract: An erosion and vibration resistant nozzle apparatus is disclosed for earth drilling rock bits. The nozzle includes a flow bean that is retained in a nozzle cavity by a threaded retainer, the retainer having at least one axially aligned slot therethrough to more fully engage the roots and crests of the retention threads to firmly secure the nozzle bean within its nozzle cavity. The split retainer may also have a conically shaped interior opening that conforms to a cone shaped exterior of the exit end of the nozzle bean for a more secure retention of the nozzle body within the nozzle cavity.

Abstract: A positive displacement grease pump apparatus is disclosed to circulate a lubricating grease from a grease reservoir system, formed within a body of a sealed bearing rotary cone rock bit. The relatively viscous grease is positively circulated to and from the reservoir through bearings defined between a rotary cone and its respective journal bearing extending from the rock bit body.