Thin section three ring bearing

A bearing assembly for rotatably coupling at least a first member and a second member, the second member being rotatable about a central axis extending through the first member, the bearing assembly comprising:

• an inner ring disposable about the first member and having an inner raceway;
• an outer ring disposed about the inner ring and disposable within a bore of the first member or within a bore of a third member disposed about the first member, the outer ring having an outer raceway;
• a middle ring disposed between the inner ring and the outer ring and having an inner intermediate raceway facing the inner raceway and an outer intermediate raceway facing the outer raceway, the middle ring being configured to connect with the second member so as to be rotatable about the central axis;
• a first set of rolling elements disposed between the inner ring and the middle ring so as to be rollable along the inner raceway and along the inner intermediate raceway during rotation of the middle ring;
• and
• a second set of rolling elements disposed between the outer ring and the middle ring so as to be rollable along the outer raceway and along the outer intermediate raceway during rotation of the middle ring;
• wherein the outer ring has an outside diameter and an axial width and is sized such that a ratio of the outside diameter to the axial width is greater than eight to one (8:1) so as to minimize an axial space required to install the bearing assembly within the first member or between the first member and the third member;
• and
• wherein the material of the inner ring and the material of the outer ring is one of 52100 alloy steel and 440C stainless steel, each one of the inner ring and the outer ring is hardened to a value of at least fifty on the Rockwell hardness C scale (50 HRc), the material of the middle ring is one of 4140 alloy steel, 4143 alloy steel and 4150 alloy steel and the middle ring is hardened to a value of no greater than forty on the Rockwell hardness C scale (40 HRc).