工程背景
A moldable gear is more than a tooth form placed on a hub. The web, hub, gate, wall transitions and ejection strategy influence the finished tooth geometry.
Uniform sections and balanced geometry help cooling, while abrupt thick-to-thin transitions can create sink or differential shrinkage. Tooth tips and roots also need to release from the tool without damage.
Gear teeth themselves may be thin while the hub is relatively heavy. That thickness contrast is a classic source of uneven cooling. A webbed or cored hub can sometimes improve molding balance, but the redesign must still carry torque from the bore to the teeth. DFM should therefore connect flow and cooling recommendations to the mechanical load path instead of treating them as separate objectives.
图纸需要传达的信息
Review tooth geometry together with hub diameter, web thickness, bore features, gate location, parting line and the expected shrinkage of the selected resin.
尽可能将这些信息添加到受控图纸、规格说明或询价附件中。避免在非正式的沟通渠道中发布这些信息，有助于供应商比较和后续修改的管理。
风险评估
Late changes to hub or wall geometry can move the process window after the gear tooth design was already frozen.
样品验收
Inspect first samples for both gear characteristics and molded-part effects such as runout or distortion.
For Plastic Gear Design for Injection Molding, close the DFM loop by updating the controlled CAD/drawing and sample plan. A recommendation that never reaches the released revision cannot be inspected consistently in production.
从设计评审到询价
Before requesting a price for plastic gear design for injection molding, identify the current drawing revision, production quantity, material constraint and the feature that most strongly affects function. Ask the supplier to flag any deviation from those inputs in the quotation so technical alternatives stay visible.
针对此决策的实用设计审查
Material selection should connect the polymer to the function and manufacturing route. Review temperature, moisture, chemicals, stiffness, wear pair, dimensional stability and exact grade requirements. A material that performs well in isolation can still be a poor choice when the mating surface or inspection condition is different.
将假设条件记录在图纸或询价单中，以便供应商在报价前进行确认。如果某个数值未知，应将其标识为待定工程项目，而不是直接复制可能与实际装配不符的通用产品目录编号。
验证工作表
- Service temperature
- Moisture / chemical exposure
- Load and stiffness need
- Wear pair / lubrication
- Dimensional-stability priority
- Exact grade or approved substitution limits
使用第一个样品，通过尺寸验证和相关的功能检查来确认这些要点。任何可接受的偏差都应在重复生产前的受控修订中记录下来。
