Innovative air spring design saves weight in commercial vehicles

At the second ‘VDI Conference: Plastics in Commercial Vehicles’ in Mannheim, Hubertus Gawinski, head of research and development at ContiTech, highlighted the potential for reducing the weight of commercial vehicles through the use of air springs with fibreglass-reinforced plastic roller pistons that are said to be up to 75% lighter than conventional steel pistons. The design of the air springs is also claimed to offer the better damping and ride comfort.

Modern commercial vehicles and buses have to meet strict requirements regarding transport efficiency. The challenge is to increase the pay load while ensuring compliance with statutorily limited axle loads in order to increase the efficiency of goods transportation. Here, reduced weight not only means reduced fuel consumption and, in turn, reduced operating costs: "An important economic aspect is the opportunity to increase the load capacity,” said Gawinski. “With our weight-reduced air springs, manufacturers can save 12 to 15kg per axle. Given a service life of 400,000km, this means a 200kg reduction in CO2 emissions."

Air spring systems with plastic pistons are already in use, particularly in trailers. However, these conventional systems only use the internal volume for ride comfort. The associated pistons are generally completely closed. "With the correct raw material, the necessary analysis skills, and an intelligent product design, we can achieve the strength that allows us to produce an open plastic system with a useful piston volume," added Gawinski.

Trucks have a service life of around 24 years before being sent to a recycling company. During this time, they clock up high annual mileage, with their components frequently being exposed to high stress levels. ContiTech says that its plastic pistons need no additional surface protection in order to safeguard the component's corrosion resistance, meaning the durability of its air spring system is guaranteed, even under adverse weather conditions.