Torque fluctuation inhibiting device, torque converter and power transmission device

A torque fluctuation inhibiting device for inhibiting torque fluctuations in a rotor into which a torque is inputted, the torque fluctuation inhibiting device comprising:

• a mass body disposed in alignment with the rotor in an axial direction, the mass body rotatable with the rotor, the mass body rotatable relative to the rotor;
• a centrifugal element disposed to receive a centrifugal force to be generated by rotation of the rotor and the mass body;
• and
• a cam mechanism including a cam and a cam follower configured to move along the cam, the cam mechanism configured to convert the centrifugal force that acts on the centrifugal element into a circumferential force when a relative displacement occurs between the rotor and the mass body in a rotational direction due to the centrifugal force, the circumferential force directed to reduce the relative displacement, wherein
• the cam is a recessed portion of a radially outer surface of the centrifugal element, the recessed portion being recessed radially inwardly from the radially outer surface of the centrifugal element,
• the cam follower is provided on either of the rotor and the mass body,
• the centrifugal element has a shape extending in the rotational direction, the centrifugal element including a guide part on both ends thereof in the rotational direction, the guide part making contact with a member adjacent thereto so as to guide movement of the centrifugal element,
• the cam and the cam follower make contact with each other at a first contact point before the relative displacement occurs between the rotor and the mass body in the rotational direction, and the cam and the cam follower make contact with each other at a second contact point after the relative displacement occurs between the rotor and the mass body in the rotational direction, the second contact point being different from the first contact point, and
• the guide part of the centrifugal element makes contact with the member adjacent thereto in an opposite position to the second contact point relative to a center of gravity of the centrifugal element.