A light beam receiver for a laser beam of a laser positioning device comprising a diffuse reflection surface embodies a reflection surface and at least one reflector surface facing the laser beam inclined at an angle <45\xb0. The laser is mounted in a laser housing so that its laser light output is directed toward a laser housing wall opening in a laser housing wall of the laser housing. In other embodiments, a vertical pump may be provided so as to include an oil recirculation system which enables an oil-based lubricant to be utilized instead of grease. The trench has a first opening at the first surface, and has a second opening at the second surface.