Xerox C2424 Service Manual - Page 81

Drum Maintenance System The drum maintenance system creates a thin, intermediate, liquid transfer surface, a layer of silicone oil, on the surface of the drum prior to printing. The oil keeps the ink from sticking to the drum's surface and facilitates its transfer to the sheet of paper or transparency film. The oil is contained in a porous foam roller. Prior to each print, the process motor drives a cam to raise the pivot plate, which raises the oil roller against the rotating drum. The same cam raises the compliant wiper blade to assure that the oil film is smooth and even across the drum's surface. The process drive rotates in one direction. This rotates the drum maintenance camshaft and raises the drum maintenance system to the drum. The process drive then rotates in the opposite direction to lower the drum maintenance system. The blade removes oil and drains it back into the maintenance kit drawer through a felt filter. The oil roller can then reuse the oil. As the drum completes one rotation, the rotating cam lowers the oil roller and then lowers the blade. The drum has a floating deadband, the narrow section of the drum containing excess oil and other debris. The oil bar is left on the drum surface when the blade is removed from the drum. This oil bar location is controlled to keep it outside of the print area. An EEPROM chip, built-in to the maintenance kit, stores the number of oiling cycles performed by the drum maintenance system. The EEPROM stores the number of prints remaining to track consumable life. At printer startup, four oiling cycles are performed to condition the drum. Drum Oil On Drum Blade Drum Maintenance Maintenance Roller Camshaft Drum Maintenance Pivot Plate Theory of Operation s2424-040 2-37