A locking system comprising: a first nut arranged on a shaft and adapted to contact with an upper side of an inner ring of the bearing; a second nut arranged on the shaft and separated from the first nut at a predetermined distance; and at least one locking screw adapted to be screwed at least through a first through hole of the second nut and a second through hole of the first nut while the first through hole and the second through hole are aligned with each other, to thereby apply a force to a bearing on the shaft along an axial direction of the shaft wherein the at least one locking screw comprises: a first locking screw adapted to be screwed through the first through hole and the second through hole while the first through hole and the second through hole are aligned with each other, a second locking screw adapted to be screwed through a third through hole of the second nut and a fourth through hole of the first nut while the fourth through hole and the fifth through hole are aligned with each other; and a third locking screw adapted to be screwed through a fifth through hole of the second nut and a sixth through hole of the first nut while the fifth through hole and the sixth through hole are aligned with each other; characterised in that while the at least one locking screw is screwed into the first through hole and the second through hole, the at least one locking screw is further adapted to apply the force to a further bearing via a spacer arranged between the bearing and the further bearing. a first nut arranged on a shaft and adapted to contact with an upper side of an inner ring of the bearing; a second nut arranged on the shaft and separated from the first nut at a predetermined distance; and at least one locking screw adapted to be screwed at least through a first through hole of the second nut and a second through hole of the first nut while the first through hole and the second through hole are aligned with each other, to thereby apply a force to a bearing on the shaft along an axial direction of the shaft wherein the at least one locking screw comprises: a first locking screw adapted to be screwed through the first through hole and the second through hole while the first through hole and the second through hole are aligned with each other, a second locking screw adapted to be screwed through a third through hole of the second nut and a fourth through hole of the first nut while the fourth through hole and the fifth through hole are aligned with each other; and a third locking screw adapted to be screwed through a fifth through hole of the second nut and a sixth through hole of the first nut while the fifth through hole and the sixth through hole are aligned with each other; characterised in that while the at least one locking screw is screwed into the first through hole and the second through hole, the at least one locking screw is further adapted to apply the force to a further bearing via a spacer arranged between the bearing and the further bearing. a first locking screw adapted to be screwed through the first through hole and the second through hole while the first through hole and the second through hole are aligned with each other, a second locking screw adapted to be screwed through a third through hole of the second nut and a fourth through hole of the first nut while the fourth through hole and the fifth through hole are aligned with each other; and a third locking screw adapted to be screwed through a fifth through hole of the second nut and a sixth through hole of the first nut while the fifth through hole and the sixth through hole are aligned with each other; characterised in that while the at least one locking screw is screwed into the first through hole and the second through hole, the at least one locking screw is further adapted to apply the force to a further bearing via a spacer arranged between the bearing and the further bearing.