Patent ID: 6427787
Filing Date: 2002-08-06
Classification: E21B,F04C

Abstract:
A drilling motor that operates pursuant to the Moineau principle for drilling deep holes or wells in the ground, comprising:a helically extending rotor disposed in a stator having a rigid shell that is provided on the inside with an inwardly helically extending lining of elastomeric material for receiving the rotor, wherein the shell is provided with essentially cylindrical end sections having an inner thread for securement of connection elements of said drilling motor, wherein a portion of said shell disposed between said end sections extends helically in conformity with said lining such that at least said lining has an essentially uniform thickness over the length of said shell portion, and wherein said shell, between said end sections, has a thickness that is less than that of said end sections, with an average thickness of said end sections being approximately 1.5-3 times greater than said thickness of said shell.