In a fuel pump in the form of a side-channel pump for a motor vehicle two
partially annular ducts (21, 22) concentrically enclosing one another are
connected to one another via a connecting duct (29). Connections (33, 34)
of the connecting duct (29) to the partially annular ducts (21, 22) are
laid so that at a rated speed of the fuel pump the same pressure prevails
in each of them. If the speed falls below the rated speed, fuel passes
from the radially outer, partially annular duct (22) into the radially
inner, partially annular duct (21). A sufficient delivery capacity
through the radially inner, partially annular duct (21) is thereby
ensured.