An apparatus for use in a drill string configured for use in a subterranean formation includes a drive shaft coupled to a drill bit, the drill bit configured to continuously rotate and penetrate within the subterranean formation, a drill string housing that houses the drive shaft, the drive shaft continuously rotating within the drill string housing relative to the drill string housing, and a bearing assembly configured bear the drive shaft within the drill string housing, the bearing assembly comprising a first bearing surface having a first curvature.