| 主权项 |
1. A bicycle hub comprising:
a one-piece hub body defining longitudinal rotational axis, the hub body including an internal cavity that extends from a first end of the hub body to an opposed second end of the hub body, the hub body including an external surface defining a first radially extending spoke support flange located at the first end of the hub body and a second radially extending spoke support flange located at the second end of the hub body and a body portion extended therebetween, wherein the internal cavity of the hub body defines a first internal cylindrical surface defined by a first constant diameter located at the first end of the hub body, a second internal surface adjacent the first internal surface, a third internal cylindrical surface defined by a second constant diameter located adjacent the second internal surface; an axle including a first end portion and a second end portion, the axle extending through the internal cavity of the hub body in a coaxial arrangement; a first bearing set located at the first end portion of the axle configured to interface between the axle and the first internal cylindrical surface of the hub body to facilitate relative rotation between the axle and the hub body; a cassette driver including a longitudinal rotational axis arranged coaxially with the longitudinal rotational axis of the hub body, the cassette driver including an internal cavity that extends from a drive end to an opposed driven end, wherein the drive end includes:
an annular opening positioned within the hub body and terminating at a distal end, the distal end located between the first and second radially extending spoke support flanges, the second end portion of the axle extending through the annular opening;a first external cylindrical surface located at a first radial distance from the longitudinal rotational axis of the cassette driver, the first external cylindrical surface radially overlapping the third internal cylindrical surface of the hub body;a second external cylindrical surface located at a second radial distance from the longitudinal rotational axis of the cassette driver, the second radial distance being larger than the first radial distance, the second external cylindrical surface being closer to the driven end of the cassette driver than the first external cylindrical surface, wherein the second external cylindrical surface is harder than the surface of the internal cavity of the hub body and has a surface finish of less than or equal to Rz of 2.5 micrometers; anda third external cylindrical surface located at a third radial distance from the longitudinal rotational axis of the cassette driver, the third radial distance being larger than the second radial distance, the third external cylindrical surface being closer to the driven end than the second external cylindrical surface; a second bearing set located at the second end portion of the axle, the second bearing set configured to interface between the axle and the internal cavity of the cassette driver to facilitate relative rotation between the axle and the cassette driver; a third bearing set located between the first external cylindrical surface of the driven end of the cassette driver and the third internal surface of the hub body to facilitate relative rotation between the cassette driver and the hub body; a fourth bearing set located between the third external cylindrical surface of the driven end of the cassette driver and the hub body configured to facilitate relative rotation between the cassette driver and the hub body; a sprag sleeve pressed into the hub body in radial alignment with a portion of the second external cylindrical surface of the driven end of the cassette driver, wherein the sprag sleeve has a cylindrical internal surface that is harder than the surface of the internal cavity of the hub body; and an annular sprag cage having a plurality of sprags that are tension biased directly against the second external cylindrical surface of the driven end of the cassette driver and radially aligned with the sprag sleeve. |
