Custom Plastic Spur Gears For The Automotive Industry

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An automotive industry client based out of Detroit, Michigan, was experiencing frequent problems with the gear teeth of a die cast spur gear used in the automobile doors for window wind-up assemblies. Since replacement of these gears required an extensive operation to completely disassemble the door panel mechanism assembly, the client contracted Advanced Molding Technologies to develop a plastic gear to replace the metal die cast gear.

In consultation with the customer, AMT selected a heavily reinforced plastic material, 50% glass-filled Grivory, to reengineer the part. Mold flow analysis was conducted to optimize the mold design and process control, including design and use of a hot runner system with three gates per part in this new 4-cavity mold. Only virgin material was used for consistent process control.

The failure rate for these new plastic gears was reduced to almost nothing. Millions of gears were produced by AMT and the customer was so pleased that they awarded Advanced Molding Technologies a “Core Supplier” status.

Metal Replacement Plastic Gear for Automotive Industry

Custom Plastic Spur Gears Project Details

Product Description		This spur gear with cable guides is used for window windup mechanism in the automobile doors assembly in the automotive industry

Capabilities Applied/Processes		Injection Molding, Hot runner system In-process controls for capability Gear data monitoring Torque testing to ensure tooth strength

Equipment Used to Manufacture Part		Horizontal Injection Molding Machine Hot Runner Controller Mold Temperature Controller

Overall Part Dimensions		3.25" Ø, 1.25" deep, 39 teeth

Tightest Tolerances		As per print

Material Used		50% GF Grivory

Color		Black

Estimated Part Weight		44 gms.

Industry for Use		Automotive

Delivery Location		Detroit, Michigan

Standards Met		Customer-supplied print, 2D CAD drawing

Product Name		Window Wind-up Gear