Rotary electric machine

1. A rotary electric machine comprising a rotor that is linked to a crankshaft of an engine so as to be driven to rotate by mechanical power from said engine, wherein:

said rotor includes:

a cylindrical rotor core that is produced so as to have a cylindrical shape by laminating electromagnetic steel sheets;

magnets that are respectively housed in a plurality of magnet housing apertures that are formed circumferentially so as to pass axially through an outer circumferential side of said rotor core, said magnets being fixed to said rotor core using an adhesive; and

a rotor boss that includes:

a cylindrical rotor ring that holds said rotor core;

an annular mounting portion that is linked to said crankshaft so as to be disposed coaxially at a first axial end inside said rotor ring; and

a linking plate that links said rotor ring and said mounting portion; and

said linking plate is formed so as to have a curved shape that is convex toward a first axial end or a second axial end of said rotor boss, and has a thickness that reduces continuously or discontinuously from a radially inner side toward a radially outer side or from said radially outer side toward said radially inner side,

wherein said linking plate includes:

a ring-shaped flat plate portion that has a constant thickness, said ring-shaped flat plate portion being disposed at an intermediate position between said mounting portion and said rotor ring;

a radially inner curved portion that links said mounting portion and said ring-shaped flat plate portion, that has thickness that reduces or increases continuously from said radially inner side to said radially outer side so as to become equal to said thickness of said ring-shaped flat plate portion; and

a radially outer curved portion that links said rotor ring and said ring-shaped flat plate portion, that has a thickness that increases or reduces continuously from said radially outer side to said radially inner side so as to become equal to said thickness of said ring-shaped flat plate portion.

2. The rotary electric machine according to either of claim 1 , wherein said rotor boss includes:

a radially inner part in which said mounting portion and said linking plate are formed integrally; and

a radially outer part that is constituted by said rotor ring,

said rotor boss being configured by joining said linking plate and said rotor ring by welding.

3. The rotary electric machine according to claim 1 , wherein said linking plate is formed by pressing so as to have a curved shape.

4. The rotary electric machine according to claim 1 , wherein:

a positioning flange portion is formed on a second axial side of an outer circumferential surface of said rotor ring; and

said rotor core is held so as to be fitted over said rotor ring so as to be in contact with said positioning flange portion.

5. The rotary electric machine according to claim 4 , wherein only said rotor core is held by said rotor ring.

6. The rotary electric machine according to claim 4 , wherein:

an end plate is mounted so as to be fitted over said rotor ring so as to be positioned radially inside said magnet housing apertures, and so as to contact a first axial end surface of said rotor core; and

said end plate and said rotor core are pressed and held between a radially outward crimping portion on a first axial end portion of said rotor ring and said positioning flange portion such that axial movement is restricted.