Abstract: In a rotor for a centrifugal separator there is delimited at one rotor end a distribution chamber (24) for a pressurized liquid supplied to the rotor for being cleaned from particles, and at the opposite rotor end there are liquid outlets arranged for reaction drive of the rotor. The liquid outlets open on the rotor outside in a liquid free space radially spaced from the rotational axis of the rotor. The separation chamber (7) of the rotor, which is situated between the distribution chamber (24) and the outlets (27), contains arcuate separation discs (11), which are distributed around the rotational axis (10) of the rotor and formed such that a lot of axially extending separation channels are delimited, which have a relatively small through-flow resistance to liquid to be cleaned. The separation channels extend axially from the distribution chamber (24) to a collecting chamber (25).