Patent ID: 9587436
Date: 2017-03-07
CPC Classifications: E21B,F16D

Claim:
1. An apparatus for transmitting torque to a down hole motor in a down hole drilling assembly, wherein the down hole motor having an output and the down hole drilling assembly includes a bearing assembly having an input, the apparatus comprising: a center rod having a distal protuberance section and a proximal protuberance section positioned at opposite ends of the center rod, wherein the distal protuberance section and the proximal protuberance section each includes a base portion and first and second prongs spaced opposite each other and extending axially from the base portion and terminating at an end surface, wherein each of the first and second prongs includes an outer curved surface, an inner curved surface, and two angled surface faces interconnecting the outer and inner curved surfaces, wherein the distal protuberance section and the proximal protuberance section each further includes a material bridge portion extending axially from the base portion and terminating below the end surface of the first and second prongs, each material bridge portion including a recess for accommodating a female insert, wherein each material bridge portion strengthens either the distal protuberance section or the proximal protuberance section during operation as torque is transferred to the bearing assembly; a transmission adapter having a first end configured to connect to the output of the down hole motor and a second end including a transmission socket profile configured to receive the first and second prongs of the proximal protuberance section, wherein the first prong of the proximal protuberance section is disposed within and directly engages a first cavity of the transmission socket profile and the second prong of the proximal protuberance section is disposed within and directly engages a second cavity of the transmission socket profile for direct transmission of torque between the center rod and the transmission adapter; a bearing adapter having a first end operatively connected to the center rod and a second end configured to connect to the input of the bearing assembly.