Abstract: An improved O-ring seal for rock bit bearings is formed from a resilient elastomeric composition comprising a multiplicity of low friction wear resistant particles distributed uniformly throughout the composition. The low friction wear resistant particles can have a rounded or non-rounded configuration. The low friction wear resistant particles located near the surface of the O-ring are exposed through wear of the elastomeric component to form wear pads that contact adjacent rotating rock bit sealing surfaces. The wear pads serve to reduce the break-off friction between the adjacent sealing surfaces and minimize the occurrence of stick-slip, thereby enhancing the service life of the O-ring seal and rock bit.

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.