Mating powder metal gear to shaft

A rotating assembly comprising:

• a gear-and-shaft assembly comprising:
• a gear, the gear including a gear body, the gear body including an inner-cylindrical surface, the inner-cylindrical surface defining a centered-through hole, the gear being a sintered metal;
• and
• a shaft, the shaft including an external spline, the external spline including external teeth, the external teeth being aligned parallel to a center axis of the gear-and-shaft assembly, the external teeth including flanks, a top land, and fillet roots, the flanks adjoining between the top land and the fillet roots, a flank angle being an angle between the flanks of adjacent of the external teeth, the flank angle being between 80 degrees and 100 degrees, a root diameter of the external teeth being between 92% and 98% of an outer diameter of the top land, the gear and the shaft being fit together and configured to rotate together about the center axis, the inner-cylindrical surface and the external spline including an interference fit, the top land abutting the inner-cylindrical surface, the interference fit being between the inner-cylindrical surface and the top land, the external spline being softer than the gear, the interference fit deforming the top land and the flanks, the flanks including deformed sections, the deformed sections adjoining the top land;
• a rotor;
• and
• a radial bearing, the shaft adjoining between the gear, the rotor, and the radial bearing.

A method comprising:

• forming a gear, the gear including a gear body, the gear body including an inner-cylindrical surface, the inner-cylindrical surface defining a centered-through hole, the gear being a sintered metal;
• forming an external spline in a shaft, the external spline including external teeth, the external teeth being aligned parallel to a center axis of a gear-and-shaft assembly, the external teeth including flanks, a top land, and fillet roots, the flanks adjoining between the top land and the fillet roots, a flank angle being an angle between the flanks of adjacent of the external teeth, the flank angle being between 80 degrees and 100 degrees, a root diameter of the external teeth being between 92% and 98% of an outer diameter of the top land;
• and
• pressing the gear onto the external spline, the gear and the shaft being fit together and configured to rotate together about the center axis, the inner-cylindrical surface and the external spline including an interference fit, the top land abutting the inner-cylindrical surface, the interference fit being between the inner-cylindrical surface and the top land, the external spline being softer than the gear, the interference fit deforming the top land and the flanks, the flanks including deformed sections, the deformed sections adjoining the top land.