A rotational sliding bearing having a static part and a mobile part, each having a sub-shell with a sliding surface, each surface arranged within an angular range of max. 180° relative to the rotational axis in the direction of rotation of the bearing, and in a closed rest position, the sub-shells of all parts together form a bearing bush, the mobile part is arranged to pivot about a pivot axis for opening the bearing relative to the static part, such that a shaft mounted in the bearing is released in a release position, and the mobile part is shaped such that, based on the sliding surface position relative to the rotational axis, in the closed rest position, a translation of a shaft accommodated in the bearing is prevented transversely to the rotational axis and in the direction of the pivot axis of the mobile part or in the counter direction.