Force transmission mechanism and instrument

A force transmission mechanism that is provided in an instrument and that transmits a driving force to an end effector from a force generator, the instrument including the end effector, a joint section that is configured to be flexed or curved, and the force generator that generates the driving force, the end effector, the joint section, and the force generator being arranged in sequence along a longitudinal axis from a distal end, the force transmission mechanism comprising:

• a force adjuster that is disposed between the joint section and the force generator, the force adjuster transmitting the driving force applied from the force generator and that is configured to change a force transmission efficiency;
• and
• a driving member that is configured to connect the end effector and the force adjuster via the joint section and transmit the driving force applied from the force adjuster to the end effector,
• wherein the force adjuster converts the driving force into a linear force along the longitudinal axis via a rotational force around a rotational axis extending along the longitudinal axis, and
• wherein the force adjuster increases a conversion efficiency from the driving force to the linear force such that an amount of increase in the force transmission efficiency increases with increasing displacement amount of the driving member when the driving member is displaced along the longitudinal axis in accordance with flexing or curving of the joint section.