Patent ID: 8746431
Filing Date: 2014-06-10
Classification: F16D,Y10T

Abstract:
1. A power transmission device comprising: a tubular first rotator having a bottom portion, an outer surface of the tubular first rotator at a location other than said bottom portion having a predetermined first diameter, and an axial direction, the first rotator having a recess or a projection on an outer surface of the bottom portion of the first rotator, wherein the outer surface of the bottom portion has a predetermined second diameter, the predetermined second diameter of the outer surface of the bottom portion being smaller than said predetermined first diameter; a shaft-shaped second rotator arranged rotatably within the first rotator, the second rotator being arranged coaxially with the first rotator; a clutch mechanism arranged between the first rotator and the second rotator and provided with at least one clutch engaging portion where torque transmitting elements of the clutch engage one another for coupling the first rotator and the second rotator so as to transmit torque; a flanged coupling member coupled to the first rotator so as to be prevented from rotating relative to the first rotator; and a bolt axially coupling the flanged coupling member to the first rotator, the flanged coupling member including: a shaft portion having a diameter smaller than the predetermined second diameter of the first rotator, a flange portion in contact with the outer surface of the bottom portion of the first rotor in the axial direction and extending radially outwardly from the shaft portion, and an engagement portion extending in the axial direction from the flange portion in an opposite direction to the shaft portion, the engagement portion having a radially inner periphery engaged with the outer surface of the bottom portion of the first rotator, the engagement portion having an engagement projection or an engagement recess, wherein the engagement projection or engagement recess of said engagement portion is provided radially outside of said shaft portion of the flanged coupling member and radially outside of said at least one clutch engaging portion of said clutch mechanism, wherein a head of the bolt is at least partly arranged at the same location as the engagement portion of the flanged coupling member in the axial direction, and wherein the first rotator is fastened to the flanged coupling member with the bolt inserted into the first rotator coaxially with the shaft portion, and the engagement projection or the engagement recess of the engagement portion is engaged with the recess or the projection of the first rotator, whereby the flanged coupling member is coupled to the first rotator so as to be prevented from rotating relative to the first rotor.