Applications for Differential Phase-Shifters

Register Control Between Print Units on an Offset Rotary Printing Press:

It is essential that the rotary impression on the print cylinder lines up exactly (in register) with the printed impression on the paper web in order to obtain a multi-color graphic print.   Therefore it is necessary to adjust the angular position of the print cylinders in each print unit relative to the other print units.

The DR differential phase-shifter works in two modes to meet this requirement:

Normal Operation:

The input shaft (N1) is integral with the line-shaft and the output shaft (N2) drives the print unit, at a right-angle, with a speed reduction ratio of exactly 2.0:1 when the adjusting shaft (N3) is stationary.  This provides an exact speed match between the print cylinder rotational speed and the linear speed of the web.

Register Control:

The small (low HP) register control motor drives the adjusting shaft (N3) to advance or retard the angular position of the print cylinders relative to the printed impression.   The correction ratio of 135:1 provides 2.667º of cylinder adjustment for each revolution of the adjusting shaft.

The DR differential phase-shifter provides the following performance advantages in this application:

• Large diameter, torsionally stiff input shaft (N1) minimizes line-shaft vibrations.
• Minimum backlash and low transmission error insures excellent print quality.
• Output shaft (N2) bearing arrangement provides long life and rigid support for the print unit drive pinion.
• Correction ratio of 135:1 requires minimum drive power and insures precise angular position of print cylinders.

Other Applications:

• Speed and Position Control

To insure proper selection, please consult the factory. If you have any questions regarding the information provided here or require more information, please call us at (800) 713-6170 or e-mail us. Our Sales and Engineering departments are ready to help you with your specific power transmission needs.