Patent ID: 7559710

Claim:
A rotary-torque adjuster that adjusts rotary torque of a rotational member, the rotary-torque adjuster comprising: a rotary shaft; the rotational member secured to the rotary shaft and rotating integrally with the rotary shaft; a plurality of clutch disks rotatably attached to the rotary shaft; a driver that drives the clutch disks; a plurality of presser components attached to the rotary shaft and rotating integrally with the rotary shaft, the presser components sandwiching opposite surfaces of the clutch disks by a predetermined pressure; and a drive transmission unit that makes a selection from among the plurality of clutch disks so as to transmit a driving force from the driver to the selected one or more clutch disks, wherein the drive transmission unit changes the selection of the clutch disks to which the driving force from the driver is to be transmitted so as to change the rotary torque of the rotational member.