Automotive brands are under increasing pressure to comply with strict government mandates to reduce fossil fuel emissions from internal combustion engines (ICE). This has driven up demand for electric engine actuators, including electronic throttle control (ETC), exhaust gas recirculation (EGR), and turbo actuators (e.g. waste gate actuators), which improve engine efficiency by reducing exhaust emissions. Next-generation hybrid engines need actuators too, to minimize fuel emissions that are generated by the ICE components in the vehicle. As a result, numerous actuator suppliers are competing for business from global automotive engine manufacturers.
These OEMs require actuators that are highly durable, and sufficiently compact to fit in the vehicle’s engine bay. For engine actuator suppliers, this means developing parts using material solutions that respond to customers’ design and performance requirements. A key challenge to meeting these needs is finding a material suitable for producing small-sized gears that fit into compact actuator designs and operate well in high-temperature under-the-hood conditions.
Polyphthalamide (PPA) is commonly used to manufacture high-temperature gears. However, due to its limited durability performance, the material isn’t ideal for engine actuator gears with strict space constraints. In addition to extreme heat resistance requirements, these gears need to withstand high torque levels for extended periods of time. Under these conditions, smaller or thinner PPA gears are more likely to wear out or break prematurely. This may lead to the actuator malfunctioning, costly repairs, or even a product recall.
Some gear manufacturers opt to improve the durability performance of PPA gears through additional design efforts. Yet, these processes tend to result in large, bulky gears that don’t easily fit into compact actuator designs, or may cause damage once fitted into a space that’s too tight. This approach often results in longer productions times, added material costs, and an end-product that may ultimately fail to meet the needs of engine manufacturers. More actuator suppliers are searching for a cost-effective, highly durable replacement material that overcomes their design challenges.
DSM’s Stanyl PA46 is a best-in-class semi-crystalline aliphatic polyamide ideal for high-temperature actuator gears. When molded into thin, lightweight parts, the material maintains its outstanding mechanical properties in under-the-hood conditions, including high fatigue and creep resistance, excellent wear performance and low friction properties. The material’s superior flow properties enable manufacturers to easily produce gears that meet stringent actuator design requirements, without compromising performance.
Stanyl PA46 gears molded 6mm thick offer durability performance equal to or greater than 10mm PPA-based competitors. The material allows manufacturers to reduce gear width and weight, as well as the amount of space used inside actuator housings by 40%. This level of design freedom is essential to potential customers looking for suppliers able to help them meet requirements for compact actuator designs – and the need for less material allows manufacturers to cut expenses by 10% or more. Due to its inherently high performance in gears, Stanyl PA46 doesn’t require expensive fillers, such as carbon fiber or W&F optimizers, which are sometimes used to enhance PPA. This enables manufactures to further reduce their total costs.
By delivering the optimal balance of design freedom, performance and cost, Stanyl PA46 offers more value than competing gear solutions. Gear durability testing shows that the material achieves better resistance to both tooth flank wear and tooth root fractures, compared to PPA competitors. Compared to specialty PPA and PA66 grades that use carbon fiber reinforcement or W&F optimizers, standard glass-fiber reinforced Stanyl PA46 gears often offer similar or longer part lifetimes, superior torque resistance and lower material costs. The material is also lighter, less expensive, and can be made into gears that are less noisy than metal alternatives.
With more than 20 years of experience in the automotive industry, DSM is trusted by industry-leading OEMs, system developers and component suppliers. Together with our industry partners, we annually produce around 100 million gears used in roughly 40 million actuators – that require 2 to 3 gears on average – for a variety of vehicle applications.
To support our global customers with their application development efforts, we offer in-depth material and design-related support, as well as application-specific expertise. As your complete material solutions partner, we’re ready to help you develop actuators that meet your customers’ expectations and drive business growth.
03 March 2021
Advanced material selection for automotive gears & actuation
Adnan Hasanovic is technical manager for gear actuators at Envalior. In this global role, he focuses on tribological applications, such as gears and bushings, as well as structural applications for gear housings and covers. Adnan also supports global DEP activities in existing and new application areas. He joined Envalior after he completed studies of mechanical engineering. Before joining Envalior, Adnan worked as application development engineer and CAE engineer.
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