Patent ID: 8662205
Filing Date: 2014-03-04
Classification: E21B,F16F

Abstract:
1. A vibration damping system for use in a drill string for drilling a drill hole, comprising: a bearing comprising a first member and a second member coupled to the first member so that the first member can translate in an up-hole and a down-hole direction in relation to the second member and a torque applied to the bearing can be transferred between the first and the second members; a valve assembly comprising a first member securely coupled to the first member of the bearing so that the first member of the valve assembly can translate in the up-hole and down-hole directions with translation of the first member of the bearing, a second member securely coupled to the second member of the torsional bearing so that the second member of the valve assembly can translate in the up-hole and down-hole directions with translation of the second member of the bearing, the first and second members of the valve assembly defining a first and a second chamber, the first and second chambers configured to hold a supply of a fluid and permit the fluid to flow between the first and the second chambers in response to relative movement of the first and second members of the valve assembly and a device configured to adjust a flow resistance of the fluid; and a spring assembly comprising a first member securely coupled to the first member of the valve assembly so that the first member of the spring assembly can translate in the up-hole and down-hole directions with the first member of the valve assembly, a second member securely coupled to the second member of the valve assembly the so that the second member of the spring assembly can translate in the up-hole and down-hole directions with translation the second member of the valve assembly, and a spring for resisting relative movement of the first and second members of the spring assembly.