Acer S2W 3300U Service Manual - Page 18

This mechanism transfers the rotation of stepping motor into linear motion. Through this mechanism the scan module can smoothly move at will in the scanning process. The description of the gear train is as following: A. Gear train The gear train's diagram is shown in Fig.4-8. Their sizes are listed in Tab.5. The purpose of the gear train is to reduce the speed of the stepping motor. The transmission ratio is 1:6, which can be easily calculated. In addition, the transmission ratio is 1:6 for the resolution of 600 DPI. Gear Gear10t25t BeltGear Pulley Teeth 10T/25T 36T None Table 5 Gear Size Figure 4-8 The Gear Train Diagram of 600 DPI