a reservoir 150 that is equipped to accommodate a lubricant 155 is configured on the spindle nut 115 the reservoir 150 is located in the axial extension of the internal thread 120 of the spindle nut 115 in so doing the reservoir 150 is preferably designed rotationally symmetrical in particular circularly cylindrical in relation to the axis of rotation 125 the spindle 105 is equipped to pass through a maximum axial deflection path along the axis of rotation 125 a segment of the spindle 105 always lies in the reservoir 150 independently of the position of the spindle 105 on the deflection path thereof as a result the spindle 105 can extend with an axial end more or less deeply into the reservoir 150 or as is shown in the embodiment depicted can completely pass through the reservoir 150 a sealing element 160 is preferably provided in order to seal the reservoir 150 at a first axial end with respect to the spindle 105 the segments of the external thread 110 of the spindle and the internal thread 120 of the spindle nut 115 which mesh with each other are located at the other axial end of the reservoir 150 a displacement element 165 is attached to the spindle 105 in the region of the reservoir 150 the displacement element 165 extends further in the radial direction than the external thread 110 of the spindle 105 and can have various shapes as is described below in more detail in reference to fig3.