METHOD FOR OBTAINING A ROTOR FOR A ROTARY ELECTRIC MACHINE
A method for obtaining a rotor of a rotary electric machine including a rotor body, a magnetic element and a ring. The method includes a step of positioning the rotor body inside an injection mould and a step of placing the ring inside the injection mould, such that the ring is placed around the rotor body. The magnetic element is injection moulded, in the form of a bonded magnet, between the rotor body and the ring.
1 . Method for obtaining a rotor of a rotary electric machine comprising a rotor body, a magnetic element and a ring, the obtaining method comprising the following steps:
positioning the rotor body inside an injection mould;
placing the ring around the rotor body in such a way as to form an annular chamber;
injection moulding the magnetic element, in the form of a bonded magnet, in the annular chamber.
2 . Method for obtaining a rotor according to claim 1 , wherein the rotor body comprises scores, a portion of the bonded magnet being inserted in the scores on the rotor body during the step of injection moulding.
3 . Method for obtaining a rotor according to claim 1 , wherein the ring comprises notches, a portion of the bonded magnet being inserted in the notches on the ring during the step of injection moulding.
4 . Method for obtaining a rotor according to claim 1 , comprising a step of pre-magnetization of the bonded magnet inside the injection mould, this pre-magnetization step involving several coils arranged in the injection mould around an area where the ring is placed.
5 . Method for obtaining a rotor according to claim 1 , comprising a step of magnetization of the bonded magnet outside of the injection mould.
6 . Rotor of a rotary electric machine that can be produced according to the obtaining method of claim 1 , the rotor having an axis of rotation and comprising a rotor body and a ring arranged around the rotor body in such a way as to form an annular chamber, and a bonded magnet arranged in said annular chamber.
7 . Rotor according to claim 6 , wherein the bonded magnet comprises tabs which extend in a plane perpendicular to the axis of rotation of the rotor inside the rotor body and/or the ring.
8 . Rotor according to claim 7 , wherein the tabs of the bonded magnet extend inside scores on the rotor body.
9 . Rotor according to claim 7 , wherein the tabs of the bonded magnet extend inside notches on the ring.
10 . Rotor according to claim 6 , wherein the ring comprises at least one collar, preferably castellated, partially covering the bonded magnet.
11 . Rotor according to claim 6 , wherein the bonded magnet has an axial end edge which contributes to forming an axial peripheral edge of the rotor.
12 . Rotor according to claim 6 , wherein the bonded magnet is made of a ferrite or rare earth alloy and a non-magnetic binder material.
13 . Rotary electric machine comprising a rotor according to claim 6 and at least a stator.
14 . Method for obtaining a rotor according to claim 2 , wherein the ring comprises notches, a portion of the bonded magnet being inserted in the notches on the ring during the step of injection moulding.
15 . Method for obtaining a rotor according to claim 2 , comprising a step of pre-magnetization of the bonded magnet inside the injection mould, this pre-magnetization step involving several coils arranged in the injection mould around an area where the ring is placed.
16 . Method for obtaining a rotor according to claim 2 , comprising a step of magnetization of the bonded magnet outside of the injection mould.
17 . Rotor of a rotary electric machine that can be produced according to the obtaining method of claim 2 , the rotor having an axis of rotation and comprising a rotor body and a ring arranged around the rotor body in such a way as to form an annular chamber, and a bonded magnet arranged in said annular chamber.
18 . Rotor according to claim 8 , wherein the tabs of the bonded magnet extend inside notches on the ring.
19 . Rotor according to claim 7 , wherein the ring comprises at least one collar, preferably castellated, partially covering the bonded magnet.
20 . Rotor according to claim 7 , wherein the bonded magnet has an axial end edge which contributes to forming an axial peripheral edge of the rotor.