Driving force transmitting unit, insertion instrument, rotary unit, insertion body assembly, and insertion device

A driving force transmitting unit in an insertion device, the insertion device including

• an insertion section extending along a longitudinal axis,
• a rotary unit provided to an outer peripheral side of the insertion section rotatably relative to the insertion section in directions around the longitudinal axis,
• a base portion which is provided in the insertion section in a state that the rotary unit is attached rotatably in the directions around the longitudinal axis and which defines a cavity open to an outside and an inside of the insertion section,
• an actuation unit which is attached to the base portion to be located in the cavity and which is actuated in a state that the rotary unit is attached to the base portion, and thereby is configured to transmit a rotation driving force to rotate the rotary unit to the rotary unit,
• a holding section which is provided to a proximal direction side with respect to the insertion section and in which an insertion hole open to an outside of the holding section is formed,
• a driving source unit which is provided in the holding section or removably attached to the holding section, the driving source unit including a driving source which is driven so as to generate the rotation driving force, and
• a channel defining portion which defines a channel extending to the cavity of the base portion from the insertion hole of the holding section through an inside of the holding section and through an inside of the insertion section,
• the driving force transmitting unit being removably attached to the actuation unit in the cavity when inserted through the channel from the insertion hole, the driving force transmitting unit being configured to transmit the rotation driving force to the actuation unit by rotating around a driving axis when the driving force transmitting unit is attached to the actuation unit,
• the driving force transmitting unit comprising:
• a line portion which extends along the driving axis in the channel when the driving force transmitting unit is attached to the actuation unit, and which is insertable into the channel through the insertion hole and removable from the channel through the insertion hole;
• a distal connection portion which is provided in a distal portion of the line portion and which is connected to the actuation unit when the driving force transmitting unit is attached to the actuation unit;
• a driving force receiving portion which is provided in a proximal portion of the line portion or provided to the proximal direction side with respect to the line portion and which is located and set at a position to receive the rotation driving force from the driving source unit when the driving force transmitting unit is attached to the actuation unit;
• a slider portion which is attached to the proximal portion of the line portion and which is movable relative to the line portion along the driving axis;
• and
• an urging portion having a distal end connected to the line portion and a proximal end connected to the slider portion, the urging portion being configured to contract in response to a movement of the slider portion relative to the line portion toward a distal direction and thereby configured to apply an urging force toward the distal direction to the line portion and the distal connection portion.