Apparatus for transferring electrical energy between rotating and non-rotating members of downhole tools

Abstract

In general, the present invention provides a contactless apparatus for power and data transfer over a gap between rotating and non-rotating members of downhole oilfield tools. The gap usually contains a fluid, such as drilling fluid, or oil for operating hydraulic devices in the downhole tool. The downhole tool in one embodiment is a drilling assembly wherein a drive shaft is rotated by a downhole motor to rotate the drill bit attached to the bottom end of the drive shaft. A substantially non-rotating sleeve around the drive shaft includes at least one electrically-operated device. An electric power and data transfer device transfers electric power and data between the rotating and non-rotating members. An electronic control circuit associated with the rotating member controls the transfer of power and data from the rotating member to the non-rotating member. An electrical control circuit carried by the non-rotating member controls the transfer of data from sensors and devices carried by the non-rotating member to the rotating member.

Dependencies are inferred from the claim text.