Patent EP-3793065-A1 (EP)
Inventor: LUCCHI GIORGIO
IPC: H02K1/27
Filed: 2020-09-14
Abstract: Rotor (1) for an axial-flux electric machine (2), said rotor (1) being configured for turning about an axis of rotation (X) of its own, said rotor (1) comprising at least one rotor part (10) of a first type, adapted to be mounted on the rotary shaft (3) of the electric machine (2), wherein said rotor part (10) of the first type comprises a supporting structure (100) and a plurality of permanent magnets (101) supported by the supporting structure (100). The supporting structure (100) is a discoid structure having an axis (102) coinciding with the axis of rotation (X) of the rotor (1). The supporting structure (100) comprises: a central portion (103) centered on the axis (102) and having a seat (104) shaped as a cylindrical through hole around the axis (102) for insertion and connection to the shaft (3) of the electric machine (2); an annular structure (105) centered on the axis (102) and surrounding the central portion (103), said annular structure (105) being connected to the central portion (103) by first and second radial connection elements (106, 107). The first connection elements (106) are mutually angularly spaced apart in a first plane (P1) perpendicular to the axis (102), each pair of successive first connection elements (106) defining, in combination with the annular structure (105) and the central portion (103), a respective first through hole (110). The second connection elements (107) are mutually angularly spaced apart in a second plane (P2) perpendicular to the axis (102) and spaced out relative to the first plane (P1) along the axis (102), each pair of successive second connection elements (107) defining, in combination with the annular structure (105) and the central portion (103), a respective second through hole (111). Each permanent magnet (101) is inserted and supported in a respective first through hole (110) with its north pole and its south pole aligned in succession along a line parallel to the axis (102), wherein the south-north vector of the permanent magnet (101) defines a magnetic axis (M) of the permanent magnet (101), the plurality of permanent magnets (101) being arranged along a circumference (C1) centered on the axis (102) and lying in a plane perpendicular to the axis (102), wherein the permanent magnets (101) are arranged in succession along said circumference (C1) with their magnetic axes (M) oriented in opposite directions, in an alternate manner, parallel to the axis (102). The rotor part (10) of the first type further comprises a magnetic-flux conveying device formed by a plurality of magnetic-flux conveying elements (114) made of a material with high magnetic permeability, each one of the second through holes (111) containing and supporting a respective conveying element (114), said conveying elements (114) being arranged along a respective circumference (C2) centered on the axis (102) and lying in a respective plane perpendicular to the axis (102). The permanent magnets (101) and the conveying elements (104) are positioned on opposite sides of the supporting structure (100) along the axis (102) of the supporting structure (100). Each conveying element (114) faces towards and is in contact with a respective one of said first connection elements (106). Each permanent magnet (101) faces towards and is in contact with a respective one of said second connection elements (107). Each permanent magnet (101) faces towards two conveying elements (114), said two conveying elements (114) being successive around the axis (102) and separated by the second connection element (107) facing towards and in contact with said permanent magnet (101).