A rotor lamination assembly of a motor, formed with a central hole and having a central axis that goes through the central hole, wherein the rotor lamination assembly is further formed with an even number of permanent magnet mounting holes (32a, 32b) arranged between a rim of the central hole and an outer rim of the rotor lamination assembly, the outer rim of the rotor lamination assembly has a projection on a plane substantially perpendicular to the central axis, and the projection comprises: an even number of base curve edges; an even number of protruding curve edges; and connecting curve edges; wherein each protruding curve edge is arranged between two adjacent base curve edges in a circumferential direction of the central axis, the protruding curve edges and the base curve edges are connected with each other through the connecting curve edges, wherein every two mounting holes (32a, 32b) which are arranged symmetrically relative to a radial axis going through a projection point of the central axis on a plane substantially perpendicular to the central axis and a middle point of the base curve edge constitute a mounting hole group, wherein a supporting portion is disposed between the two mounting holes and corresponds with a respective base curve edge in the circumferential direction of the central axis, and edges of the two mounting holes of the mounting hole group which are farthest from each other are respectively arranged on the circumferential direction and correspond with the two adjacent protruding curve edges characterized in that: the base curve edges comprise circular arcs which have a center which is deviated from the projection point of the central axis; and the protruding curve edges comprise circular arcs which take the projection point of the central axis as a center and the central hole comprises a curve edge which is concentric with the protruding curve edges. an even number of base curve edges; an even number of protruding curve edges; and connecting curve edges; wherein each protruding curve edge is arranged between two adjacent base curve edges in a circumferential direction of the central axis, the protruding curve edges and the base curve edges are connected with each other through the connecting curve edges, wherein every two mounting holes (32a, 32b) which are arranged symmetrically relative to a radial axis going through a projection point of the central axis on a plane substantially perpendicular to the central axis and a middle point of the base curve edge constitute a mounting hole group, wherein a supporting portion is disposed between the two mounting holes and corresponds with a respective base curve edge in the circumferential direction of the central axis, and edges of the two mounting holes of the mounting hole group which are farthest from each other are respectively arranged on the circumferential direction and correspond with the two adjacent protruding curve edges characterized in that: the base curve edges comprise circular arcs which have a center which is deviated from the projection point of the central axis; and the protruding curve edges comprise circular arcs which take the projection point of the central axis as a center and the central hole comprises a curve edge which is concentric with the protruding curve edges.