An exemplary gear transmission device includes a driving assembly including a driving shaft, a shaft coupling, a circular driving gear, a resilient mechanism and a driven gear engaging with the driving gear. The shaft coupling is fixed to the driving shaft and rotatable in unison with rotation of the driving shaft. The circular driving gear substantially surrounds and is operatively coupled to the shaft coupling and rotatable under urging of the shaft coupling. The resilient mechanism is held between the driving gear and the shaft coupling and is elastically deformable in circumferential directions of the shaft coupling. When the driving gear moves axially and collides with the driven gear without meshing with the driven gear, the driving gear rotates slightly relative to the shaft coupling thereby elastically deforming the resilient mechanism and the driving gear reaches a position where it can mesh with the driven gear.