Polymer Gear Test Rig

Design and Development

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High performance, high cost reinforced polymer materials necessitates the optimum utilization of the material in a product. Selective reinforcement is one way to develop high performance gears economically since all the gear regions doesn't carry the load. Multi shot injection molding process is followed to develop the selective reinforced gear. Multi shot injection-molding process.

Duplex gears are designed and developed using a high performance high cost short carbon fiber reinforced Nylon 6/6 material in the highly stressed tooth region and low cost unreinforced Nylon 6/6 material in the hub region.

Unreinforced Nylon 66 material is injected into gear hub and the molded hub is placed inside another die. The selective reinforced gear is obtained by injecting carbon reinforced Nylon into the cavity containing premolded hub. The processing is done in a simple semi automatic injection-molding machine. Selectively reinforced gear with spline hub exhibits almost same the fatigue behavior similar to the monolithic gear. No failures were observed at the interface. The cost of selective reinforced carbon reinforced gear is about 23 % lower than the identical monolithic gear.