This invention relates to a trunnion assembly (10) comprising a trunnion shaft (12) and a housing (14) defining a bore (16) for rotatably and concentrically receiving the trunnion shaft (12). The trunnion assembly (10) further includes a bearing assembly (18) located inside the housing (14) and surrounding the trunnion shaft (12). The bearing assembly (18) allows rotation of the shaft (12) in the bore (16) whilst also allowing movement of the shaft (12) out of concentric alignment with the bore (16). The bearing assembly (18) includes a toroidal-type roller bearing assembly (20), which allows for misalignment of the shaft (12) inside the bore (16). The bearing assembly (18) further includes a re-aligning means that re-aligns the longitudinal axis B of the shaft (12) with the longitudinal axis C of the bore (16), after the said misalignment.