05135059 is referenced by 22 patents and cites 39 patents.

A downhole drilling motor includes a rotor and stator of the Moineau positive displacement type within a housing. A drive shaft is rotatably mounted within the housing. A flexible shaft with a polygonal connection at each end transmits the rotational motion of the rotor to the drive shaft while compensating for the eccentric movement of said rotor within said stator relative to said drive shaft.

Title
Borehole drilling motor with flexible shaft coupling
Application Number
7/615602
Publication Number
5135059
Application Date
November 19, 1990
Publication Date
August 4, 1992
Inventor
Peter R Harvey
Hartford
CT, US
William E Turner
Middlefield
CT, US
Agent
Fishman Dionne & Cantor
Assignee
Teleco Oilfield Services
CT, US
IPC
E21B 4/00
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