A sheet material transport apparatus includes a second planetary gear engaging with a transmission gear and providing planetary motion around the transmission gear. The second planetary gear is in a second separated position not capable of engaging with a first planetary gear during forward-direction rotation. The transmission gear engages with the first planetary gear and rotates in a direction that causes a second transport roller to rotate in the forward rotation direction, and positioned to engage with the first planetary gear that is positioned in a first engaging position during reverse rotation. A load is placed on the transmission gear by the second transport roller. The transmission gear rotates in the opposite direction to the forward-direction rotation. The second planetary gear applies a force on the first planetary gear in the direction that separates the first planetary gear from the transmission gear due to rotation.