DOWNHOLE BEARING ASSEMBLY WHICH ACCOMMODATES COMPRESSIVE AND TENSIL AXIAL LOADING

摘要

A bearing assembly for bearing tensile and compressive axial loads. In preferred embodiments, the invention is a bearing assembly for use downhole, including a first member and a second member with coinciding central longitudinal axes, and a thrust bearing subassembly in a chamber between the first and second members defined by two shoulders of the first member and two shoulders of the second member. The second member is free to rotate, and has at least limited freedom to translate axially, relative to the first member. The thrust bearing subassembly's overall axial length is such that the first member can translate axially relative to the second member between a first configuration in which the thrust bearing subassembly bears a tensile axial load and a second configuration in which it bears a compressive axial load. The thrust bearing subassembly includes a pair of side members and a bearing between the side members. Each side member has a flat end face and an angled end surface having a central portion farthest from (or nearest to) the flat end face and two outer portions which meet at an angle at the central portion. Each outer portion of each angled end surface faces a shoulder of the first member or the second member, and each shoulder has a profile which matches that of the outer portion facing it. Each shoulder bears against an angled end surface portion in either the first or second configuration, but is held off that angled end surface portion in the other one of the configurations.