Abstract: A shaft includes a bushing for a current conductor, and a holder for positioning the current conductor. The holder secures the current conductor in or over an inflection point of a curve of the current conductor.

Abstract: A system for drilling a borehole into the earth's subsurface includes a drill bit configured to rotate and penetrate through the earth's subsurface, and a vibration isolation device configured to isolate vibration that is caused at the drill bit, the vibration having an amplitude. The amplitude of the vibration downhole of the vibration isolation device is at least 20% higher than the amplitude of the vibration uphole of the vibration isolation device.

Abstract: A device for transferring torque to a drill bit in a borehole having a borehole axis includes a support element configured to rotate in the borehole about the borehole axis, a torque transferring element configured to transfer torque from the support element to the drill bit and further configured to isolate torsional oscillations that are created at the drill bit from the support element, a blocking element configured to block rotation of the torque transferring element relative to the support element about the borehole axis in at least one direction, and a bearing element between the support element and the drill bit.

Abstract: Methods and systems for damping torsional oscillations of downhole systems are described. The systems include a downhole string, a bit support assembly configured to support and receive a disintegration device, wherein the disintegration device is disposed on an end of the downhole string and mounted to the bit support assembly, and a damping system configured at least one of on and in the bit support assembly, the damping system comprising at least one damper element arranged in contact with a portion of the bit support assembly.

Abstract: Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a damping system configured on the downhole system. The damping system includes a first element and a second element in frictional contact with the first element. The second element moves relative to the first element with a velocity that is a sum of a periodic velocity fluctuation having an amplitude and a mean velocity, wherein the mean velocity is lower than the amplitude of the periodic velocity fluctuation.

Abstract: Methods and systems for damping torsional oscillations of downhole systems are described. The systems include a downhole string, a bit support assembly configured to support and receive a disintegration device, wherein the disintegration device is disposed on an end of the downhole string and mounted to the bit support assembly, and a damping system configured at least one of on and in the bit support assembly, the damping system comprising at least one damper element arranged in contact with a portion of the bit support assembly.

Abstract: Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a damping system configured on the downhole system. The damping system includes a first element and a second element in frictional contact with the first element. The second element moves relative to the first element with a velocity that is a sum of a periodic velocity fluctuation having an amplitude and a mean velocity, wherein the mean velocity is lower than the amplitude of the periodic velocity fluctuation.

Abstract: A device for transferring torque to a drill bit in a borehole having a borehole axis includes a support element configured to rotate in the borehole about the borehole axis, a torque transferring element configured to transfer torque from the support element to the drill bit and further configured to isolate torsional oscillations that are created at the drill bit from the support element, a blocking element configured to block rotation of the torque transferring element relative to the support element about the borehole axis in at least one direction, and a bearing element between the support element and the drill bit.