Abstract: A down hole vibration dampener is disclosed that uses a set of polyurethane rings and steel support rings to create a shock absorber within the drill string to reduce the amount of vibration in the drill string. A splined mandrel extends longitudinally within a hollow cylindrical housing. A seal structure present between the exterior of the mandrel and the interior of the housing forms a lubricant receiving chamber. The series of polyurethane and steel rings are located in the lubricant chamber and are compressible longitudinally to absorb vibration and shock loads.

Abstract: A down hole vibration dampener is disclosed that uses a set of polyurethane rings and steel support rings to create a shock absorber within the drill string to reduce the amount of vibration in the drill string. A splined mandrel extends longitudinally within a hollow cylindrical housing. A seal structure present between the exterior of the mandrel and the interior of the housing forms a lubricant receiving chamber. The series of polyurethane and steel rings are located in the lubricant chamber and are compressible longitudinally to absorb vibration and shock loads.

Abstract: A tilted drive sub is disclosed with a center line of the internal diameter (ID) offset at an angle from the center line of the outer diameter (OD) starting at a point near to a top end of the tilted drive sub. This results in the ID being at an angle to the OD, with the OD of the tilted drive sub remaining straight. The offset ID has the same threads of a mud motor without a tilted drive sub. The tilted drive sub replaces the outer bearing housing of a normal performance mud motor.