A spur gear transmission has at least two meshing, toothed spur gears. A covering wall surrounds the spur gears circumferentially and in the direction of their rotational axes. The covering wall has an inner contour adapted to the outer diameters of the spur gears. Two annular gaps which transition into each other are formed between the covering wall and the spur gears. The annular gap is substantially concentric to a rotational axis. The covering wall surrounds the two spur gears circumferentially only over a part of the circumference, with a part of the outer circumference of the two spur gears or one of the two spur gears protruding outwards out of the covering wall. The part of the two spur gears or of the one spur gear that protrudes out of the covering wall is positioned on the lower face of the spur gears.