Abstract: A downhole communication includes an antenna winding fixed to an inner surface of a collar. A fluid flow flows through a center of the antenna winding. The antenna winding is wound around a chassis in an antenna channel in the chassis. The chassis is attached to the inner surface of the collar with a seal such that fluid does not travel between the fluid flow and an annulus between the antenna winding and the inner surface of the collar.

Abstract: A downhole turbine includes a plurality of fins. The plurality of fins have an exit angle that exerts a tangential force on the fin, which imparts a torque on a hub. The fins have an adjustable exit angle that changes in response to changes in the properties of a drilling fluid. The changing exit angle changes the tangential force, which changes the torque on the hub.

Abstract: A control unit includes a rotatable tubular body that rotates around a spindle. A torque transfer unit may be attached to the tubular body and the spindle. A force applied to the torque transfer unit by a biasing element may control a first torque applied by the tubular body to the spindle. The first torque is independent of a rotational velocity of the tubular body. A second torque is applied to the spindle with a torque generator, the second torque controlling the net torque. Controlling the net torque allows the absolute orientation of the control unit to be controlled.

Abstract: A downhole turbine includes a plurality of fins. The plurality of fins have an exit angle that exerts a tangential force on the fin, which imparts a torque on a hub. The fins have an adjustable exit angle that changes in response to changes in the properties of a drilling fluid. The changing exit angle changes the tangential force, which changes the torque on the hub.

Abstract: A downhole communication includes an antenna winding fixed to an inner surface of a collar. A fluid flow flows through a center of the antenna winding. The antenna winding is wound around a chassis in an antenna channel in the chassis. The chassis is attached to the inner surface of the collar with a seal such that fluid does not travel between the fluid flow and an annulus between the antenna winding and the inner surface of the collar.

Abstract: A control unit includes a rotatable tubular body that rotates around a spindle. A torque transfer unit may be attached to the tubular body and the spindle. A force applied to the torque transfer unit by a biasing element may control a first torque applied by the tubular body to the spindle. The first torque is independent of a rotational velocity of the tubular body. A second torque is applied to the spindle with a torque generator, the second torque controlling the net torque. Controlling the net torque allows the absolute orientation of the control unit to be controlled.

Abstract: A downhole communication includes an antenna winding fixed to an inner surface of a collar. A fluid flow flows through a center of the antenna winding. The antenna winding is wound around a chassis in an antenna channel in the chassis. The chassis is attached to the inner surface of the collar with a seal such that fluid does not travel between the fluid flow and an annulus between the antenna winding and the inner surface of the collar. A difference in diameter between an upper seal and a lower seal results in a net force to push the chassis against a shoulder on the collar.