Vibration damping device and method of designing the same

A method of designing a vibration damping device including:

• a support member that rotates together with a rotary element, to which torque from an engine is transferred, about a center of rotation of the rotary element;
• a restoring force generation member that is coupled to the support member and that is swingable along with rotation of the support member;
• and
• an inertial mass body coupled to the support member via the restoring force generation member and swung about the center of rotation in conjunction with the restoring force generation member along with rotation of the support member, the method comprising:
• preparing a dynamic model that includes the vibration damping device and a vibration suppression target to which the torque from the engine is transferred;
• deriving, for each of a plurality of orders of the vibration damping device, torque fluctuations of the vibration suppression target when an external force from the engine acts by substituting a design parameter of the vibration damping device corresponding to the order into a group of equations derived from the dynamic model;
• and
• determining the design parameter which brings the derived torque fluctuations of the vibration suppression target to a target value as a design value.

A vibration damping device of a dry type, comprising:

• a support member that rotates together with a rotary element, to which torque from an engine is transferred, about a center of rotation of the rotary element;
• a restoring force generation member that is coupled to the support member and that is swingable along with rotation of the support member;
• and an inertial mass body coupled to the support member via the restoring force generation member and swung about the center of rotation in conjunction with the restoring force generation member along with rotation of the support member, wherein
• a reference order, which is a convergent value of an order of the vibration damping device when an amplitude of vibration of input torque transferred to the rotary element becomes smaller, is higher than an excitation order of the engine.