VICTREX® PEEK(TM) Polymer Helps Wuxi Shuangling Create Safe and Reliable Engine Vacuum Pump Vanes


WEST CONSHOHOCKEN, PA, USA - Wuxi Shuangling, a leading Chinese automotive parts maker, has selected VICTREX® PEEK(TM) polymer for the manufacture of its vacuum pump vanes. These vanes are used in rotary vane pumps in diesel and turbocharged direct-injection gasoline engines for some of China's top automotive makers.

Vacuum pumps provide braking assistance (through a brake booster) and support the supercharging and exhaust gas recirculation. They contribute to the overall safety and efficiency of the braking system by reducing the amount of pedal effort required for braking. Since any failures or deterioration in the performance of a vacuum pump would have an adverse effect on the braking performance of an automobile and may even lead to accidents, auto makers have established stringent requirements for the reliability and performance of vacuum pumps prior to assembly. The vane type pumps supply brake boosters with negative pressure of 0.9 bar (1,880 lbs/sq ft) to reduce braking efforts for drivers.

In order to keep the pump vanes working efficiently, they require high wear resistance in the tip area, low coefficient of friction particularly for electrical pumps, tight dimensional tolerances, thermal expansion similar to or slightly greater than aluminum, and a high strength/weight ratio. In addition, driven by pedestrian safety legislation, the position of the pumps has moved nearer the oil sump, meaning that they experience increasing service temperatures up from 100 to 110°C and 120°C to 130°C (212 to 230°F and 248 to 266°F). By working alongside Victrex Polymer Solutions, Wuxi Shuangling provides customers with high performance components that can meet these requirements in the harsh operating environments of automotive applications over traditional materials like polyphenylene sulfide (PPS) and graphite.

Selection of materials is critical to the performance and operating reliability of vacuum pumps. VICTREX PEEK polymer has excellent resistance to automotive fluids and has demonstrated a very good compressive creep resistance at elevated temperatures. It is a unique material which maintains high mechanical strength at 150°C (302°F) for 5,000 hours or more and resists brittleness when stressed by mechanical and frictional loads. It withstands the forces generated during cold starting [-40°C (40°F)]) where the engine oil has a relative high viscosity. The material's excellent wear resistance results in a longer service life.

"We believe that by using VICTREX PEEK polymer we will be able to offer customers a top-quality vacuum pump and an innovative solution to enhance their competitiveness. The low density of the Victrex wear grades helps us to reduce CO2 because the moment of inertia of the component is reduced compared to other materials like highly filled PPS," said Li Huicheng, Deputy General Manager of Wuxi Shuangling.

Wear resistance is becoming more important for vane type pumps. Due to increasing speed and temperature the load on materials increases steadily, even for lubricated mechanical pumps. If we consider a doubling of engine speed from diesel to gasoline engines centrifugal forces are proportional to pressure and increase by a factor of four, meaning that PV (pressure/velocity) values increase eight times," said Eastward Yu, Senior Market Development Manager, China, at Victrex Polymer Solutions.

In recent years, the automotive industry has faced increasing pressure to maximize performance and safety while minimizing fuel consumption, weight and cost. As a result, high durability, low cost, driving comfort, and low environmental pollution have become the core measurements of R&D efforts. Victrex's materials and deep technical support are helping automotive part makers around the world boost product performance, improve design flexibility, and extend service part life while successfully meeting the industry's demanding material requirements.

For more information, please www.victrex.com

Contact: Kris Jommersbach
Gemini Communications
PH: + (1) 610-935-1633
krisj@geminiinc.com

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