Adjustable bearing assembly

A machine tool comprising:

• a fixed frame and a tool carrier head rotatably mounted on the frame for rotation about a tool rotation axis, roller bearing elements extending between the frame and head, with either the frame or head including apertures for receiving bearing support bolts;
• bearing support bolts extending through said apertures and securing the roller bearing elements relative to either said frame or head, said bolts each having a central longitudinal axis, a head end, a central cylindrical portion concentric with the bolt longitudinal axis, and an opposed threaded end;
• a bushing associated with each support bolt, each bushing including a bushing longitudinal axis, an inner cylindrical through hole concentric with the bushing longitudinal axis that closely fits over the bolt cylindrical portion in coaxial relationship with the bolt longitudinal axis, a connector portion including an internally threaded bore that extends coaxially with the bolt longitudinal axis and that threadably engages the bolt threaded end, said bushing cylindrical through hole located between the roller bearing and the connector portion of the bushing, an outer cylindrical portion that is eccentric relative to said bushing longitudinal axis, said outer cylindrical portion disposed in close fitting relationship with a bore in said frame or head, and a radial flange portion for engaging a surface of the head or frame on the side thereof opposite the roller bearing associated with the support bolt connected to the bushing;
• said bushing adapted to be rotated in its respective bore to thereby cause the bolt longitudinal axis to be translated laterally relative to the bore due to the eccentricity between the bushing cylindrical outer surface and the longitudinal axis;
• and said bushing, including said connector portion, outer cylindrical portion and flange portion constituting a one-piece structural element;
• said bolt head end arranged to clamp a respective roller bearing between itself and the frame or head when the bolt is threaded inwardly relative to the bushing connector portion.