By alternating spur gears made of a standard and a lubricated grade of Delrin® acetal resin, Lexmark engineers are maximizing the performance of a six-gear power train at minimum cost. The gear train is part of the toner cartridge used in Lexmark Optra™ S laser printers.
Three of the gears are used to drive two rolls and the toner paddle inside the cartridge. They are molded from standard Delrin® 500P. One of these gears (far left in the photo), has an integrally molded spoked wheel that interfaces with the printer's power train. This gear drives the cartridge's developer roll.
The three drive gears mate with three idler gears molded from a premium-performance Delrin® 500 resin with an advanced lubricant system providing very low wear and friction.
Quiet, reliable operation. The combination of lubricated and standard Delrin® provides especially quiet, smooth operation plus low wear to maintain high print quality over the long haul.
Low total system cost. By pairing gears made of standard and premium performance resins, Lexmark was able to meet its performance targets at minimum cost.
Technical assistance. DuPont and Winzeler engineers assisted Lexmark in material selection and design, thus helping the company reach its time and cost goals.
No contamination risk. The lubricity of Delrin® avoids the need for oil or grease that could contaminate toner and paper.
Materials Selected and Why
Delrin® grades meet needs for dimensional stability, strength, low wear and friction, and high molding productivity. In addition to these characteristics, one grade of Delrin® provides added lubricity for even lower wear and friction, and quieter gear operation.