Abstract: An apparatus (1) for rotational motion about a rotational axis (14) of a first member (2) relative to a second member (3), the first member having an outer surface being rotational symmetric about the rotational axis, and the second member having a corresponding rotational symmetric cavity with an inner surface accommodating at least part of the first member with an interspace between the outer surface of the first member and the inner surface of the second member. A repulsive magnetic field (4) between the first and the second member prevents contact between the outer surface of the first member and the inner surface of the second member. This magnetic field is achieved by a plurality of permanent dipole magnets (6, 13) arranged in the first member and in the second member with identical polarity (7) directed towards the interspace between the first and the second member. By using a plurality of magnetic dipoles an arbitrary shape can be provided with a surface having only north or south poles of magnets.