Fuser Roller Core and Drive Collar Assembly Design for High Speed Printer

Abstract

Very high speed electrophotographic printers often use a fusing system consisting of a fuser roller and associated drive mechanisms which employ a coupled drive hub assembly. The fuser roller typically includes a metal core onto or into which a mating drive hub and collar assembly are connected. Rotating at high rotational speed, and at high temperature, with extremely fast start/stop conditions, instabilities create issues between the contacting surfaces causing micro machining issues which eventually develop failure modes of the apparatus. Such is the case in the drive system employed in printers using a drive key and drive slot configuration. The thermal expansion of the aluminum core differs significantly from the thermal expansion of the steel drive hub causing loss of contact between the mating surfaces. Micro machining occurring between the steel drive key and the aluminum core slot, widens and weakens the drive slot causing eventual failure of the roller and drive hub, sometimes catastrophic.The design of the fuser core and the drive collar assembly has undergone development that takes into account the differing thermal expansion of the aluminum fuser core and the steel drive hub. The development has been furthered by a unique design which incorporates a self locking and self centering drive mechanism, along with a rubber interface design, again taking into account for the thermal expansion of aluminum and elimination of the drive key and slot, to address the failure mechanism of the previous designs. This mechanism absorbs the shock energy of the fast start – stop motion, dissipating the energy over the full surface diameter of the drive hub. This paper describes the design history, the associated failure modes, and the new and novel solution.