V-Research GmbH
  • Tiefgründig. Die Oberfläche.

    Tiefgründig. Die Oberfläche.

[Translate to English:] Tribologische Optimierung von Kunststoffgleitlagern

[Translate to English:]

Palfinger Europe GmbH

Die Palfinger Europe GmbH ist Weltmarkt- und Technologieführer im Bereich hydraulischer Hebe-, Lade- und Handlingsysteme. Für spezielle Gleitlagerungen greift Palfinger auf Gleitlagerkunststoffe der faigle Kunststoffe GmbH zurück. faigle ist Spezialist für Kunststoffhalb- und Fertigteile mit umfassendem Know-how in der Entwicklung, Herstellung, Bearbeitung und Anwendung von Kunststoffen für verschiedenste tribologische Anwendungen (z. B. Rollen für Fahrtreppen oder Gleitplatten für Schienenfahrzeuge).

In einem gemeinsamen Forschungsprojekt mit Palfinger und faigle hat V-Research die tribologischen Wechselwirkungen in Polymergleitlagern analysiert, wie sie in den Ladesystemen für Nutzfahrzeuge und im maritimen Bereich  von Palfinger eingesetzt werden. Eine herausfordernde Aufgabe, da tribologische Systeme mit Polymeren in der Regel sehr komplex sind und zusätzlich stark von Umgebungseinflüssen wie z.B. Temperatur, Luftfeuchtigkeit usw. beeinflusst werden. Um unter diesen Voraussetzungen erfolgreich zu sein, bedient sich V-Research einer streng systematischen Methodik und der Kombination von theoretischen und experimentellen Untersuchungen des Tribosystems.

 

Durch das gemeinsame Forschungsprojekt konnte Wissen aufgebaut werden, welches direkt in der Produktentwicklung sowohl bei Palfinger als auch bei faigle genutzt werden kann. Zusätzlich konnte durch das Projekt auch die Zusammenarbeit zwischen Hersteller und Anwender gestärkt werden.

Significant improvement of quality characteristics of worm-gear screw jacks with simultaneous reduction of material and manufacturing costs

ZIMM Maschinenelemente GmbH & Co KG

ZIMM Maschinenelemente is an internationally active company with more than 35 years' experience in drive technology. With its system construction kit of worm-gear screw jacks, Zimm offers a varied range of products for precise electromechanical adjustments for linear movements of loads of up to 100 tonnes (1,000 kN) per drive.

The worm gearing and the transmission thread form the heart of the worm-gear screw jack. Because of the high slip rate and the large resulting tribological stress, these assemblies place very high demands on the materials and lubricants used.

By comprehensively redesigning the worm gearing and optimising its tribological characteristics, V-Research succeeded in increasing the service life of the lifting system by 55 per cent and the lifting capacities by 30 per cent while reducing the manufacturing and material costs by 30 per cent.

Against this background, V-Research assists ZIMM in optimising the existing material pairs, surfaces, coatings and lubricants, as well as in selecting and evaluating completely new material concepts. This allows ZIMM to adapt its products to the increasing demands of the market and to stand out from competitors' products.

Design of a lubricant-free sliding pair for large telescopic guides

Liebherr-Werk Ehingen GmbH

In 2009 and 2010, Liebherr delivered to Saudi Arabia a variety of sunshades to provide shade for pilgrimage sites in Medina. In 2012, Liebherr signed a contract with one of the leading building-project organisers in Saudi Arabia for the construction of a huge foldable sunshade for the Grand Mosque in Mecca. When open, the shade will provide shadow for an area of some 2,400 square metres. The shade diaphragm, at a height of 30 metres, has a span of 53 metres. It is pulled tight by eight telescopic arms, which each consist of a hinged part and two telescopic sections that can be extended hydraulically. V-Research found a completely new solution for the telescopic arms, or sliding pairs, that works without the greasing that is otherwise necessary. It was tested on the working model at Liebherr in Ehingen with very promising results. A shade with a total weight of 600 tonnes was then assembled and erected in Ehingen. After extensive tests in Germany, it was delivered to Saudi Arabia and this time they build it up in Mekka.

Minimisation of frictional losses and increase in product quality with static friction design

Liebherr Machines Bulle SA (Switzerland)

Liebherr has been manufacturing hydraulic components at its location in Bulle, Switzerland, for more than 30 years. These primarily include axial piston pumps and motors in a swash-plate construction. These robust machines suffer from the disadvantage that, because of their design, they have relatively high friction losses at low speeds and on start-up and therefore also tend to suffer from speed fluctuations. The reason for this lies in their construction and in the composition of the hydraulic film that serves to separate component surfaces, such as piston/cylinder or sliding shoe/sliding plate. For the tribological design, this means that solutions must be sought for the static friction regime. The tribology experts at V-Research found new material pairs and coatings, tailored to the respective load types, with which it was possible to halve the static friction. Furthermore, it was possible to identify further approaches to the substitution of the non-ferrous metals used and therefore to develop a more efficient and, at the same time, more environmentally friendly solution.

Increase in process reliability in the manufacture of injection-moulded plastic friction clutches

Hirschmann Automotive GmbH

For more than 25 years, Hirschmann Automotive GmbH has been developing and producing innovative plug connections and contact systems with matching cable sets, as well as sensor/actuator elements, for automotive use.

One actuator from Hirschmann Automotive uses mechanical friction clutches with a precisely defined maximum transmissible torque. Clutch slip at a certain torque is regarded as a prerequisite for reproducible positioning. This is extremely difficult to implement in series production, particularly in a clutch made of polymer–polymer pairs. The tribological properties of plastics are known to depend on a variety of influences. Humidity, temperature, cooling curves in the injection-moulding process, surface changes during the cooling process and relaxation of residual stresses are some examples of this. V-Research used component segments for the tribological analyses in order to comprehend the complex interaction between these influencing parameters. In this way, the contact area variations, topography and orientation of the sliding surfaces were established. The influence of these variables was therefore determined, allowing reproducible operation of the friction coupling.