Stator for a downhole fluid operated motor and method of assembling the

Abstract

A stator is disclosed for use with down-hole fluid powered drilling motors of the Moineau type. It includes a housing and a plurality of removable stator sections positioned in end-to-end, abutting relationship in the housing. Each section comprises a cylindrical body of elastomeric material having an obround opening extending longitudinally therethrough. The opening spirals along a helical path with a pitch equal to the length of the section. A method is disclosed for positioning a plurality of the sections in a statorhousing in end-to-end, abutting relationship with the opening properly oriented to form a continuous helical opening through the stator to receive a helically shaped rotor having one half the pitch of the helical opening. Each section includes a cylindrical reinforcing member embedded in the body of elastomeric material. An annular portion of the body has an outside diameter greater than the inside diameter of the housing. The annular portion is compressd between the housing and the reinforcing member when the section is installed in the housing to form a fluid seal between the housing and the section. The compressed annular portion also provides sufficient friction to hold the section from rotating relative to the housing when the rotor rotates relative to the section as fluid is forced through the opening in the section.