Rotary pump comprising: a pump chamber with a chamber base ; a rotor housed in the pump chamber and comprising a bottom base resting on the chamber base , the rotor comprising a rotor housing and configured to rotate around a rotational axis Z orthogonal to the chamber base ; a driving element intended to be housed in the rotor housing , the driving element having an external surface comprising: a contact portion comprising an spherical zone symmetrical to Z axis; and at least one lateral driving protrusion fixed to and extending from the spherical zone along a first direction (Y) orthogonal to Z axis, the at least one lateral driving protrusion being intended to transmit a rotary movement to the rotor around the rotational axis Z, and wherein the rotor housing comprises: a central recess having a diameter for accommodating the contact portion ; and at least one lateral cavity intended to house the at least one lateral driving protrusion , such that the contact portion and the central recess are slidably engageable to each other for compensating angular misalignments between an axis orthogonal to the bottom base of the rotor and the Z axis, when the bottom base of the rotor is resting on the chamber base and the at least one lateral cavity is configured to allow a relative angular movement, around any direction orthogonal to Z axis, between the at least one lateral driving protrusion and the at least one lateral cavity required by the sliding between the central recess and the contact portion , to keep the bottom base of the rotor resting on the chamber base but movable around Z axis by the pushing of the al least one lateral driving protrusion against the lateral cavity characterized in that the at least one lateral driving protrusion has the shape of a hemisphere or of a spherical segment. a pump chamber with a chamber base ; a rotor housed in the pump chamber and comprising a bottom base resting on the chamber base , the rotor comprising a rotor housing and configured to rotate around a rotational axis Z orthogonal to the chamber base ; a driving element intended to be housed in the rotor housing , the driving element having an external surface comprising: a contact portion comprising an spherical zone symmetrical to Z axis; and at least one lateral driving protrusion fixed to and extending from the spherical zone along a first direction (Y) orthogonal to Z axis, the at least one lateral driving protrusion being intended to transmit a rotary movement to the rotor around the rotational axis Z, a contact portion comprising an spherical zone symmetrical to Z axis; and at least one lateral driving protrusion fixed to and extending from the spherical zone along a first direction (Y) orthogonal to Z axis, the at least one lateral driving protrusion being intended to transmit a rotary movement to the rotor around the rotational axis Z, a central recess having a diameter for accommodating the contact portion ; and at least one lateral cavity intended to house the at least one lateral driving protrusion , such that the contact portion and the central recess are slidably engageable to each other for compensating angular misalignments between an axis orthogonal to the bottom base of the rotor and the Z axis, when the bottom base of the rotor is resting on the chamber base and the at least one lateral cavity is configured to allow a relative angular movement, around any direction orthogonal to Z axis, between the at least one lateral driving protrusion and the at least one lateral cavity required by the sliding between the central recess and the contact portion , to keep the bottom base of the rotor resting on the chamber base but movable around Z axis by the pushing of the al least one lateral driving protrusion against the lateral cavity characterized in that the at least one lateral driving protrusion has the shape of a hemisphere or of a spherical segment. <EOS>