Innovation Spotlight: DuPont™ Hytrel®

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Six-speed Transmission Baffle Assembly

Application Description

A thermoplastic elastomer (TPE) single-piece, six-speed transmission baffle assembly, replacing the incumbent stamped steel with bonded rubber seal. Developed with the Ford Motor Company for use on its 2018 Ford Focus.

Unmet Need

Material improvements to transmission baffle assembly components offer opportunities for weight reduction, cost reduction and improved fuel efficiency, as well as noise, vibration and harshness (NVH) improvements.

Challenges

  • Ability to seal against cast aluminum surfaces
  • Improved ease of assembly
  • Significant design constraints, including tight dimensional tolerances 

Solution

The part was produced using a one-step injection molding process, enabling integrated seal elements capable of sealing with a cast surface. Snap-fit assembly behavior allows the part to effectively seal five areas.

The baffle assembly:

  • Enables reduced chain and gear sprocket drag
  • Improves fuel economy
  • Enhances fluid passage to the sump for reduced pump whine noise
  • Reduces costs by approximately 30% versus previous design
  • Reduces weight by more than 50%

DuPont Material Chosen and Why

DuPont™ Hytrel® was chosen for this application because it offers:

  • Toughness and resilience
  • Flows in very thin sections to form lip seals
  • Wide temperature range
  • Resistance to ATF fluids

FINALIST, 2017 SPE AUTOMOTIVE INNOVATION AWARDS, POWERTRAIN CATEGORY