Rotor assembly

A rotor assembly for an electric machine, comprising:

• a cylindrical rotor core defining a radially-facing seat and including a longitudinal axis of rotation;
• a set of posts extending radially outward from the rotor core defining a set of slots between adjacent posts;
• a set of windings formed by conductive wire wound in the set of slots having end turns extending axially beyond the rotor core;
• and
• a pair of retention cases, each of the retention cases defining a first retaining portion radially overlying the end turns and a second retaining portion axially overlying at least an axially-facing portion of the end turns the first retaining portion having an inner surface portion having an offset angle relative to the longitudinal axis, wherein an end portion of the first retaining portion of each of the retention cases is received by the seat;
• wherein a piloting of the first retaining portion of the retention case prevents imbalance of the set of windings during a rotation of the rotor assembly, by the seat ensuring there is no radial movement of the retention case;
• and
• wherein the inner surface portion is angled such to include an increasing radial dimension along the inner surface portion while moving away from an axial-center of the cylindrical rotor core.