A method for resin coating electrical windings enclosed within a housing of a stator of an electric motor and defining a central cylindrical cavity, said method comprising the steps of: - preparing a core having an elastic wall that encloses at least one inner chamber (18,20) having an opening provided with a shut-off valve, said core having a lower disc-like portion and an upper cylindrical portion that protrudes from a surface of the lower portion, wherein said lower portion is fixed to an underlying support, within which a channel is formed communicating with the external environment and with said opening, and provided with a shut-off valve, - coupling said core and said stator, in a manner such that said upper portion of the core occupies the cavity of the stator, and said lower portion of the core is positioned within said housing below the windings, - inflating through said opening said at least one inner chamber (18,20) of the core by opening said shut-off valve and injecting air into the channel, in a manner such that said lower portion comes into contact with an inner surface of the housing and said upper portion comes into contact with the windings which define said cavity of the stator, - pouring said resin so that it coats said windings except in the parts in contact with the upper portion of the core, - curing said resin that forms a coating on said windings except on the parts in contact with the core, - deflating said at least one inner chamber (18,20) of the core through said opening so that the core is no longer in forced contact with the housing and the windings, wherein the deflating phase provides for evacuating air from the inner chamber of the core through the opening and channel by opening said shut-off valve, and - separating the core from the stator, whose windings are coated with said resin. - preparing a core having an elastic wall that encloses at least one inner chamber (18,20) having an opening provided with a shut-off valve, said core having a lower disc-like portion and an upper cylindrical portion that protrudes from a surface of the lower portion, wherein said lower portion is fixed to an underlying support, within which a channel is formed communicating with the external environment and with said opening, and provided with a shut-off valve, - coupling said core and said stator, in a manner such that said upper portion of the core occupies the cavity of the stator, and said lower portion of the core is positioned within said housing below the windings, - inflating through said opening said at least one inner chamber (18,20) of the core by opening said shut-off valve and injecting air into the channel, in a manner such that said lower portion comes into contact with an inner surface of the housing and said upper portion comes into contact with the windings which define said cavity of the stator, - pouring said resin so that it coats said windings except in the parts in contact with the upper portion of the core, - curing said resin that forms a coating on said windings except on the parts in contact with the core, - deflating said at least one inner chamber (18,20) of the core through said opening so that the core is no longer in forced contact with the housing and the windings, wherein the deflating phase provides for evacuating air from the inner chamber of the core through the opening and channel by opening said shut-off valve, and - separating the core from the stator, whose windings are coated with said resin.