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 3D scans for the automotive industry
16.01.2017 | Julius-Maximilians-Universität Würzburg

nachricht Improvement of the operating range and increasing of the reliability of integrated circuits
09.11.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen 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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>