Rotor assembly with molded fans and method for making the same

An alternator for a vehicle including:

• a housing;
• a stator having windings and being supported by the housing;
• and
• a rotor assembly cooperating with and being rotatable relative to the stator and housing, the rotor assembly including an elongated rotor shaft, a pair of annular pole pieces axially aligned along and mounted on the rotor shaft to define a region between the pole pieces, each pole piece having an outboard face, a coil wire having a plurality of turns held within the region and having a pair of free ends, a pair of slip rings which are mounted on the rotor shaft and which are connected to a pair of terminals which are attached to the respective free ends of the coil wire to form a pair of respective connections, a molded component including a molded fan integrally molded to one of the outboard faces of the pole pieces and a molded insert which at least partially fills the region between the pole pieces and which is integrally molded with the fan to secure the fan to the pole piece, the molded insert encapsulating the coil wire preventing movement between turns of the coil wire to thereby prevent fatigue failure of the coil wire.

A method for making a molded rotor assembly for a vehicle alternator, the method comprising the steps of:

• mounting a pair of pole pieces on an elongated rotor shaft with a coil wire, having a plurality of turns and a pair of free ends, being held in a region formed between the pole pieces, each pole piece having an outboard axial face;
• mounting a pair of slip rings, connected to a pair of terminals, to the rotor shaft;
• connecting free ends of the terminals to the free ends of the coil wire to form a pair of connections;
• and
• molding a molded component including at least one fan to one of the outboard axial faces of one of the pole pieces, the fan having a plurality of circumaxially spaced blades, the molded component also encapsulating at least one of the connections thereby providing structural support to the connection.

A molded rotor assembly for a vehicle alternator, the rotor assembly comprising:

• an elongated rotor shaft having a longitudinal axis;
• first and second pole pieces axially aligned along and spacedly mounted on the rotor shaft to define a region between the pole pieces, each pole piece having an outboard axial face;
• a coil wire cooperatively held in the region between the pole pieces, the coil wire having a pair of free ends;
• a pair of slip rings mounted to the rotor shaft and connected to a pair of terminals, each terminal attaching to a respective free end of the coil wire to form a pair of respective connections;
• and
• a molded fan integrally molded to at least one of the outboard axial faces, the molded fan having a plurality of circumaxially spaced blades;
• one of the outboard axial faces having a support channel formed therein with one of the terminals being received in the channel with the molded fan encapsulating that terminal within the channel thereby providing structural support to the terminal.

A method for making a molded rotor assembly for a vehicle alternator, the method comprising the steps of:

• mounting a pair of pole pieces on an elongated rotor shaft with a coil wire, having a plurality of turns and a pair of free ends, being held in a region formed between the pole pieces, each pole piece having an outboard axial face, one of the axial faces having a support channel formed therein;
• mounting a pair of slip rings, connected to a pair of terminals, to the rotor shaft;
• connecting free ends of the terminals to the free ends of the coil wire to form a pair of connections;
• placing a terminal within the support channel;
• and
• molding a molded component including at least one fan to one of the outboard axial faces of one of the pole pieces encapsulating the terminal within the channel during the molding, the fan having a plurality of circumaxially spaced blades.