Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Low abrasion DuPont™ Vespel® thrust washers for maintenance-free SUV transfer case

28.08.2008
Thrust washers made of DuPont™ Vespel® SP-21 polyimide are durable, maintenance-free components of the new Integrated Transfer Cases developed by Magna Powertrain of Lannach, Austria.

Used in premium SUVs from Land Rover and Daimler, these ITC’s are located upstream of the differential to ensure optimum torque transfer between the front and rear axles. In addition they provide the choice between two gear ratios for on-road and off-road driving, whereby selection can be made while driving.


Photo: DuPont
Low-friction and virtually abrasion-free thrust washers, made of DuPont™ Vespel® SP-21, help maximize the service life of the planetary gear train within the new integrated transfer cases from Magna Powertrain.

Two designs of Vespel® thrust washers are used in the planetary gear set for the off-road drive position. In the first design, six small thrust washers. with an outside diameter of 25 mm, absorb axial forces, generated by the helical gearing, from the three planet wheels. In the second, two much larger thrust washers, with an outside diameter of 160 mm, support the ring gear on both sides against the grey cast iron planet carrier. Without the use of the Vespel® thrust washers, the hardened steel planet wheels and ring gear would rotate directly against the comparably soft grey cast iron housing, causing the housing to wear very quickly.

Potential alternatives to Vespel® thrust washers, such as axial needle bearings, would incur relatively high additional costs. Moreover, such bearings require a larger installation space and are significantly heavier. In the quest to find a lightweight, space-saving alternative that was also cost-efficient, the manufacturer followed the advice of Austrian distributor Biesterfeld Interowa, and tested prototype parts made of Vespel®. The results were impressive, as Ernst Riegler, department manager at Magna Powertrain, confirms: “We know of no other material that combines similarly outstanding tribological properties over a wide temperature range with such low space requirement and light weight.”

The complex interaction of mechanical, chemical and thermal stresses in this application makes very high demands on the material. The low-friction Vespel® components can withstand these stresses long-term. As Riegler continues: “We design the Vespel® thrust washers used in our ITCs to last a lifetime operating with PV values of over 7 MPaxm/s. In other words: the reduction in thickness that the thrust washers sustain due to wear is so low that they never need to be changed throughout the entire vehicle service life. The axial positioning of the gear wheels remains within close tolerances and the formation of an optimum lubricating film is guaranteed.”

DuPont produces the thrust washers in-house from polyimide using a direct-forming method similar to metal powder sintering. Directly integrated oil grooves, with geometry flow-optimized by Magna, ensure a permanent thin film of lubricating oil on the thrust washers. The sintered parts require no post-finishing and are ready for immediate installation. At the same time, they meet the very close tolerances specified.

The application advantages of Vespel® SP-21 are not confined simply to low wear. The polymer has a specific gravity of only 1.42 g/cm³ for light weight parts, excellent chemical resistance for stability in a broad range of automotive lubricants and extremely high heat resistance, permitting continuous service temperatures of up to 300 °C.

Vespel® S is a family of highly-durable polyimide parts and shapes that deliver exceptional wear resistance, insulation, and a low coefficient of friction: Vespel® SP-1 combines excellent mechanical and insulation properties at high temperatures; Vespel® SP-21 is enhanced with graphite for very high abrasion resistance; Vespel® SP-211 is enhanced with DuPont™ Teflon® PTFE for a very low co-efficient of friction; Vespel® SP-22 combines low friction and high abrasion resistance with excellent dimensional stability. Further information on these grades and other Vespel® families can be found at www.vespel.com.

The DuPont Engineering Polymers business manufactures and sells Crastin® PBT and Rynite® PET thermoplastic polyester resins, Delrin® acetal resins, Hytrel® thermoplastic polyester elastomers, DuPont™ ETPV engineering thermoplastic vulcanizates, Minlon® mineral-reinforced nylon resins, Thermx® PCT polycyclohexylene dimethylterephthalates, Tynex® nylon filaments, Vespel® parts and shapes, Zenite® liquid crystal polymers and Zytel® nylon resins and Zytel® HTN high-performance polyamides. These products serve global markets in the aerospace, appliance, automotive, consumer, electrical, electronic, healthcare, industrial, sporting goods and many other diversified industries.

DuPont is a science-based products and services company. Founded in 1802, DuPont puts science to work by creating sustainable solutions essential to a better, safer, healthier life for people everywhere. Operating in more than 70 countries, DuPont offers a wide range of innovative products and services for markets including agriculture and food; building and construction; communications; and transportation.

The DuPont Oval, DuPont™, The miracles of science™, and Vespel® are registered trademarks or trademarks of E.I. du Pont de Nemours and Company or its affiliates.

This press release is based upon information provided by:
Magna Powertrain AG & Co. KG; Industriestr. 35, A-8502 Lannach, Austria
Contact: Dipl.-Ing Ernst Riegler
Telephone: +43 (0) 5 04 44 67 11
Email: ernst.riegler@magnapowertrain.com

Horst Ulrich Reimer | Du Pont
Further information:
http://www.magnapowertrain.com
http://www.dupont.com

More articles from Automotive Engineering:

nachricht When your car knows how you feel
20.12.2017 | FZI Forschungszentrum Informatik am Karlsruher Institut für Technologie

nachricht Did you know how many parts of your car require infrared heat?
23.10.2017 | Heraeus Noblelight GmbH

All articles from Automotive Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>