Repetitive moment generating device

A repetitive moment generating device that is used for a fatigue testing machine for testing a fatigue strength property by imparting a repetitive moment on a test piece, the repetitive moment generating device comprising:

• a principal shaft that is rotatably held to transmit a repetitive moment to a test piece set in the fatigue testing machine;
• a pair of lever members that are attached to the principal shaft at positions that are separated from each other in a shaft center direction of the principal shaft in a state where each of the lever members is orthogonal to the principal shaft;
• and shaft bodies that are rotatably held around shaft centers, each of which is parallel with the principal shaft, at positions that are symmetrical with the principal shaft interposed therebetween in a region where the lever members face each other;
• drive means for causing the shaft bodies to synchronously rotate;
• eccentric weight members that are attached to the shaft bodies in a state where the eccentric weight members intersect the shaft bodies and in a state where the eccentric weight members are slidable in a direction that intersects the shaft bodies;
• sliders that are attached to the shaft bodies in a state where the sliders are slidable in shaft center directions of the shaft bodies and in a state where the shaft bodies are able to idle;
• joining means for converting sliding motion of the sliders in the shaft center directions of the shaft bodies into sliding motion of the eccentric weight members in a direction that intersects the shaft bodies and transmitting the sliding motion to the eccentric weight members;
• and
• operation means for causing the sliders to slide in the shaft center directions of the shaft bodies.