Patent ID: 7895729

Claim:
A process for mounting magnets in an electric motor rotor, said rotor comprising: a lamination stack provided with a central axial bore, a plurality of axial channels disposed around the central axial bore, and axial bores disposed in a peripheral portion of the lamination stack and which are external to the axial channels; permanent magnets housed in the axial channels so as to define the rotor poles; and a rotor cage formed by a first and a second end ring, each end ring seated against a corresponding adjacent end lamination of the lamination stack and connected to the other of the rings by a plurality of bars which are cast in the axial bores in a single piece with the first and second end rings, said process comprising the steps of: forming the first end ring seated against its corresponding end lamination, with at least one inner radial projection adjacent to each axial channel, such that, for each axial channel, the at least one projection corresponding thereto is disposed radially external to a corresponding opening, in said end lamination, defined by a projection onto said end lamination of a contour of said axial channel; mounting in each axial channel at least one respective permanent magnet; and deforming each of the projections in order to increase its radial extension sufficiently to radially cover at least part of the opening corresponding thereto, thereby defining a stop for axially retaining the respective permanent magnet.