Plate cylinder driving devices of a printing machine are provided with a drive shaft driving the plate cylinder, a drive helical gear fixed to the drive shaft, and an anti-backlash helical gear rotatably connected to the drive shaft and is biased by at least a spring towards a direction for preventing backlash. Both the drive helical gear and the anti-backlash helical gear are engaged with the main gear, and a plate provided with plural holes accommodating rollers is provided between the drive helical gear and the anti-backlash helical gear. Friction between the anti-backlash gear and the drive gear is reduced by a simple mechanism in the plate cylinder driving devices in a printing machine.

Plate cylinder driving devices of a printing machine are provided with a drive shaft driving the plate cylinder, a drive helical gear fixed to the drive shaft, and an anti-backlash helical gear rotatably connected to the drive shaft and is biased by at least a spring towards a direction for preventing backlash. Both the drive helical gear and the anti-backlash helical gear are engaged with the main gear, and a plate provided with plural holes accommodating rollers is provided between the drive helical gear and the anti-backlash helical gear. Friction between the anti-backlash gear and the drive gear is reduced by a simple mechanism in the plate cylinder driving devices in a printing machine.

Plate cylinder driving devices of a printing machine are provided with a drive shaft driving the plate cylinder, a drive helical gear fixed to the drive shaft, and an anti-backlash helical gear rotatably connected to the drive shaft and is biased by at least a spring towards a direction for preventing backlash. Both the drive helical gear and the anti-backlash helical gear are engaged with the main gear, and a plate provided with plural holes accommodating rollers is provided between the drive helical gear and the anti-backlash helical gear. Friction between the anti-backlash gear and the drive gear is reduced by a simple mechanism in the plate cylinder driving devices in a printing machine.

Plate cylinder driving devices of a printing machine are provided with a drive shaft driving the plate cylinder, a drive helical gear fixed to the drive shaft, and an anti-backlash helical gear rotatably connected to the drive shaft and is biased by at least a spring towards a direction for preventing backlash. Both the drive helical gear and the anti-backlash helical gear are engaged with the main gear, and a plate provided with plural holes accommodating rollers is provided between the drive helical gear and the anti-backlash helical gear. Friction between the anti-backlash gear and the drive gear is reduced by a simple mechanism in the plate cylinder driving devices in a printing machine.