Preloading & machining mounted brake disc

A method for fabricating a brake disc assembly including an inner hub (14) extending between a drive end (16) and a wheel end (18) and a disc flange (20) extending radially about the circumference of the inner hub (14) at the wheel end (18) with the inner hub (14) having a bore (22) extending between the ends for receiving a drive shaft, a brake disc having a base (26) attached to the disc flange (20) about the circumference of the inner hub (14) and a rotor (28) extending radially from the base (26) and presenting parallel braking surfaces (30), a bearing assembly surrounding the hub (14) between the drive end (16) and the disc flange (20) for supporting the hub (14) with an outer race (32) presenting a support flange (34) for attachment to a support structure (36) and an inner race member (58) disposed about the drive end (16), said method comprising the steps of:

• preloading the bearing assembly axially;
• clamping the outer race (32) of the bearing assembly in a fixed orientation about a fixed axis (A);
• rotating the brake disc and the hub (14) relative to the outer race (32) about a rotation axis (B);
• and
• machining the braking surfaces (30) of the rotor (28) while rotating the hub (14) and brake disc relative to the outer race (32);
• said preloading step characterized by deforming an extension (70) of the drive end (16) of the inner hub (14) radially outwardly and into engagement with the bearing assembly and into a deformed portion (72) for preloading the bearing assembly in the axial direction.