Power transmission device

A power transmission device, comprising:

• a first power transmission member including first meshing portions arranged next to each other in a circumferential direction about an axis extending in a first direction, the first power transmission member being rotatable about the axis;
• and
• a second power transmission member including second meshing portions that are arranged next to each other in a second direction intersecting the first direction and are capable of meshing with the first meshing portions, the second power transmission member rotating or moving in the second direction as the first power transmission member rotates with the first meshing portions meshed with the second meshing portions, wherein
• the first power transmission member includes:
• a hub that rotates about the axis;
• a gear including the first meshing portions on an outer circumferential side of the gear and an insertion hole on an inner circumferential side of the gear, the hub being inserted through the insertion hole to be slidable in the first direction;
• a first engagement portion that moves integrally with the hub in a rotation direction of the hub;
• and
• a second engagement portion provided on the gear to be engageable with the first engagement portion in the rotation direction of the hub.