As connected car technology continues to evolve, automotive OEMs are replacing vacuum and hydraulic brakes with electric braking systems. In addition to lowering maintenance and repair costs, these systems improve fuel economy, enable a smoother driving experience, and can stop vehicles faster to prevent collisions. As a result, the global markets for electric brake boosters and electric parking brakes are expected to see a CAGR of 26.4% and 17.2% respectively by 2026.
Unlike traditional vacuum and hydraulic mechanisms, electric brakes require several gear-driven actuators to maximize system efficiency and reliability. Since electric brake booster and parking brake designs are highly compact, OEMs require actuator gears that are increasingly thin and extremely durable. This leads more gear manufacturers to leverage engineering thermoplastic materials that are more cost-effective and easier to process than metal.
Yet, polyamide 66 and polyoxymethylene (POM), two commonly used materials for actuator gears, offer limited performance in brake actuator applications. Automatic emergency braking functions built into electric brake boosters can result in high torque levels that cause PA66 and POM gear teeth to fracture or deform prematurely. Thermal performance issues that result from frictional heat dissipation and increased tooth temperature effects may also arise when these materials are used in worm gears – and may cause gear teeth to melt. A failure in any of these areas could lead to a brake malfunction with potentially life-threatening consequences.
Although additional design efforts can improve the durability of PA66 and POM, these processes typically result in bulky gears that don’t meet the actuators’ stringent packaging space and weight requirements. As more automakers invest in next-generation brake-by-wire systems, which require small and complex actuators, the demand for stronger, thinner and lighter gears is accelerating. To keep pace with customer needs, it’s critical that manufacturers leverage high-performance materials that offer ample design freedom, speed up production cycles and reduce operating costs.
DSM’s Stanyl® PA46 is a high-strength aliphatic polyamide trusted by manufacturers of automotive actuator components for more than 20 years. The material delivers best-in-class stiffness and durability performance at both moderate and high temperature levels, enabling gear suppliers to optimize final parts for under-the-hood conditions and deliver on customers’ strict design specifications. Our portfolio of thermoplastics for actuator gears also includes Akulon®, a cost-effective material well-suited for intermediate performance requirements and EcoPaXX®, a bio-based, tough and durable polyamide for applications requiring very high dimensional accuracy.
Due to its high crystallinity and unmatched heat, fatigue and wear resistance, Stanyl PA46 delivers outstanding gear performance that minimizes the risk of gear failure throughout actuator lifetimes.
DSM’s in-house, state-of-the-art gear testing capabilities enable performance testing customized to precise torque, speed and temperature levels – in either grease lubricated or dry-running conditions. Compared to PA66 and POM alternatives, Stanyl PA46 gears achieve up to 25-50% higher torque capacity at a given number of load cycles. Our teams also work with customers to optimize gear designs based on specific torque, lifetime, temperature and design space requirements for their specific applications.
Stanyl PA46’s design flexibility and easy processing capabilities enable gear suppliers to differentiate themselves in the market, speed up cycle times, and save costs. Compared to PA66 alternatives, the material allows manufacturers to reduce the space gears take up inside actuator housings by 25% – without compromising end-part performance. Standard Stanyl PA46 grades also often don’t rely on costly wear and friction optimizers or carbon fiber to improve material properties. Compared to alternative materials that contain wear and friction optimizers or carbon fiber fillers – including PA66 – Stanyl PA46 grades deliver equal or higher performance, and are more cost-effective.
Today, Stanyl PA46 is used to produce approximately 100 million gears in 40 million automotive actuators each year. As a leading supplier of engineering thermoplastics for automatic, electric, and electronic applications, we go above and beyond to ensure our customers are maximizing the value our material solutions offer. By partnering with us, you’re able to exceed OEMs’ expectations, set yourself apart from competing gear suppliers, and seize new business opportunities in the automotive market.
24 August 2021
Selecting the proper materials solution for gear applications improves durability and lifetime
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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