A wheel assembly (1a;1b;1c;2), wherein the wheel assembly comprises: - an attachment portion (3;37) for attaching the wheel assembly to an object, - a wheel house (5;43) rotatably connected to the attachment portion (3;37) about a first rotational axis (A1), - a wheel rotatably connected to the wheel house (5;43) about a second rotational axis (A2) perpendicular to the first rotational axis, and - a locking mechanism (13;38) adapted to lock the wheel house (5;43) in relation to the attachment portion (3;37) in a plurality of predefined positions, and the locking mechanism (13;38) comprises a plurality of recesses and a locking element (15;44) arranged rotatable in relation to the recesses, and the locking element (15;44) is adapted to engage with the recesses when the wheel house (5;43) and the attachment portion (3;37) are in the predefined positions in relation to each other, wherein the locking element (15;44) is arranged rotatable in relation to the attachment portion (3;37) about the first rotational axis, the locking element (15;44) is connected to the wheel house (5;43) so that a rotational movement of the locking element (15;44) achieves a corresponding rotational movement of the wheel house (5;43), and at least a part (16;45) of the locking element (15;44) is movable in a direction parallel with the first rotational axis to allow said part (16;45) of the locking element to move into the recesses and to engage with the recesses when the wheel house and the attachment portion are in the predefined positions in relation to each other, wherein said at least a part (16;45) of the locking element (15;44) is resilient in a direction parallel with the first rotational axis, characterized in that the locking element (15;44) is elongated and linearly movable in relation to the wheel house (5;43) in a direction perpendicular to the first rotational axis. - an attachment portion (3;37) for attaching the wheel assembly to an object, - a wheel house (5;43) rotatably connected to the attachment portion (3;37) about a first rotational axis (A1), - a wheel rotatably connected to the wheel house (5;43) about a second rotational axis (A2) perpendicular to the first rotational axis, and - a locking mechanism (13;38) adapted to lock the wheel house (5;43) in relation to the attachment portion (3;37) in a plurality of predefined positions, and the locking mechanism (13;38) comprises a plurality of recesses and a locking element (15;44) arranged rotatable in relation to the recesses, and the locking element (15;44) is adapted to engage with the recesses when the wheel house (5;43) and the attachment portion (3;37) are in the predefined positions in relation to each other, wherein the locking element (15;44) is arranged rotatable in relation to the attachment portion (3;37) about the first rotational axis, the locking element (15;44) is connected to the wheel house (5;43) so that a rotational movement of the locking element (15;44) achieves a corresponding rotational movement of the wheel house (5;43), and at least a part (16;45) of the locking element (15;44) is movable in a direction parallel with the first rotational axis to allow said part (16;45) of the locking element to move into the recesses and to engage with the recesses when the wheel house and the attachment portion are in the predefined positions in relation to each other, wherein said at least a part (16;45) of the locking element (15;44) is resilient in a direction parallel with the first rotational axis, characterized in that the locking element (15;44) is elongated and linearly movable in relation to the wheel house (5;43) in a direction perpendicular to the first rotational axis. <EOS>