Electric machine with a rotor assembly for rotor core retention

An electric machine, comprising:

• a rotor assembly including:
• a rotor core lamination stack arranged axially between a first end plate and a second end plate;
• and
• a rotor shaft mated with the rotor core lamination stack, the first end plate, and the second end plate;
• where the rotor shaft includes an undercut lip that includes a bent portion that contact the first end plate.

A method for manufacturing an electric machine, comprising:

• arranging a first end plate on a rotor shaft;
• machining an undercut lip at one end of the rotor shaft via machining;
• arranging a rotor core lamination stack that includes multiple laminations onto the rotor shaft;
• arranging a second end plate proximate to the undercut lip;
• compressing the rotor core lamination stack and the first end plate;
• and
• bending the undercut lip over a portion of the second end plate, via operation of an orbital forming tool, to form a flange that provides axial retention and compression to the rotor core lamination stack, the first end plate, and the second end plate.