Low-pressure pump

A rotary piston pump for gaseous media, comprising:

• an axially and radially supported power part, embodied as a spherical segment of a spur tooth and connected to a drive mechanism;
• a blocking part of a same radial sealing diameter, also embodied as a spherical segment of a spur tooth and driven by the power part;
• work chambers between the power part and the blocking part, formed by combs of teeth of the power part and of the blocking part,
• the power part and blocking part are guided radially sealingly in a pump housing and, and in which for attaining a pumping action or for generating a low pressure or vacuum, the comb of each of the power part and the blocking part have a number of teeth other than one on face ends of the power part and the blocking part cooperating with one another;
• and
• a linear form lock, defining the work chamber, between edges and combs of opposed cooperating teeth,
• the teeth of one of the power part and the blocking part cooperating with one another, as a cycloidal part, have a cycloidal layout of a bearing surface thereof,
• the teeth of a corresponding other part of the power part and the blocking part cooperating with one another, cooperating in meshing fashion with the cycloidal part, have corresponding tooth combs that are freely designable in a radius thereof and that extend along flanks of the cycloidal part, and
• the pump, formed of the power part and blocking part, is present in double fashion in each case, which double fashion pumps are driven in common, and the work chambers thereof can be made to communicate with one another,
• wherein doubly present power parts are disposed coaxially on a drive side, the first power part is driven by an electric motor disposed on the drive side, likewise coaxially, in a motor housing, and the second power part is rotated in rotationally locked fashion by the first power part.