Patent ID: 7040989
Filing Date: 2006-05-09
Classification: F16D,F16H,Y10T

Abstract:
1. A power transmission device for transmitting power generated by a drive source to a driven device, comprising: a driving-source rotating member driven to rotate by torque transmitted from said drive source; a driven-device rotating member operatively connected to said driven device to rotate together therewith; a torque transmission part for transmitting torque from said driving-source rotating member to said driven-device rotating member, including a resilient member interposed between said driving-source rotating member and said driven-device rotating member; a breakable part which breaks and interrupts the torque transmission when the transmitted torque exceeds a predetermined torque level; and means for inducing breakage that causes bending stress in said breakable part by changing relative positions of said driving-source rotating member and said driven-device rotating member in an axial direction of the rotational axis of the driven-device rotating member when a preset limit of phase difference in a direction of rotation between said driving-source rotating member and said driven-device rotating member is exceeded such that the means for inducing breakage will cause an axial force, if the phase difference between the driving-source rotating member and the driven-device rotating member exceeds the preset limit, as a result of deformation of the resilient member exceeding a predetermined amount due to a rotational force applied to the resilient member.