Patent ID: 7540361

Claim:
A bicycle wheel driving device comprising: a hub axle; a hub shell including a side end section having an internal circumferential surface with an inner diameter and a radially extending inside surface, the hub shell being rotatably disposed around the hub axle by at least one bearing; and a motor disposed inside the hub shell and configured to rotate the hub shell with respect to the hub axle; and a roller brake device coupled to the outside of the hub shell by a roller brake mounting adapter comprising a flange part extending radially outward within the hub shell and being non-rotatably mounted to the radially extending inside surface of the side end section of the hub shell, an outer end of the flange part having a first diameter; and a cylindrical part formed integrally with the flange part, the cylindrical part including an internal contact surface of the cylindrical part contacting the bearing, and first and second external contact surfaces of the cylindrical part, the first external contact surface extending outside of and away from the hub shell and having a plurality of circumferential spaced apart protrusions that are engaged with the roller brake device, the first external contact surface having a second diameter smaller than the first diameter, with the inner diameter of the side end section of the hub shell being smaller than the first diameter and larger than the second diameter, the second external contact surface axially extending from the flange part, mating with the internal circumferential surface of the side end section of the hub shell and radially outwardly supporting the internal circumferential surface of the side end section of the hub shell, with the first and second external contact surfaces being located at axial locations at least partially overlapping with the internal contact surface of the cylindrical part.