ResearchActivities

New technologies for fluid film lubrication systems

Abstract:
The focus is on the research and development of liquid lubrication technologies that significantly enhance the performance and reliability of components, machines, and systems. The solutions are flexible and effective, utilizing the methods based on both commercial and custom-developed experimental procedures. New knowledge and cutting-edge technologies of rubbing interfaces are crucial for improving functionality or creating new innovative technical solutions.

Main objectives:

  • To elucidate the mechanisms of liquid lubrication in rolling and sliding contacts, operating in the combination of surfaces (texture and/or coatings), lubricants (base components and/or additives) and material.

  • To develop advanced liquid lubrication technologies that improve lifetime, reliability and energy efficiency or enable innovative solutions.

  • To develop and implement unique optical and electrical methods for analysing and measuring tribological processes in sliding and rolling contacts in laboratory conditions that simulate real-world machine operation.

  • To provide specialized tribometers tailored to the specific needs of industrial partners, facilitating further advancements in research and product development.

Research content:
The smooth and reliable operation of many tribological interfaces in machines is enabled by correctly and optimally designed liquid lubrication technologies. The right combination of surfaces and lubricants allows long-term transmission of operating loads with minimal energy loss due to friction. The primary goal is often the full separation of surfaces by a coherent lubricating film, which depends on operational conditions, rheological properties of the lubricants, mechanical characteristics, and the geometry and topography of contact bodies. This leads to reduced wear, stable interface behaviour, and lower energy requirements for machine and system operation, ultimately contributing to decreased energy consumption and CO₂ emissions.

Research and development methodology employs both commercial and custom-developed tribometers to simulate tribological interfaces on a laboratory scale. The team is globally recognized for pioneering advanced optical methods for in-situ analysis and measurement of tribological parameters, providing deep insights into the lubrication mechanisms of frictional interfaces. Extensive expertise, combined with a wide range of experimental equipment, allows selection of appropriate configuration and experimental conditions, advanced data analysis, and precise interpretation of results.

Research and development outcomes are applied in the design of sliding and rolling conjunctions found in machines and equipment, such as rolling and sliding bearings, gears, linear guides, cams and couplings. Solutions integrate knowledge of surface engineering, lubricant rheology, and fluid mechanics, in the form of analytical and numerical models of partial phenomena or entire interfaces. These new insights and technologies are critical to advancing existing or new technical solutions.

Publications:
ZAPLETAL, T.; ŠPERKA, P.; KŘUPKA, I.; HARTL, M. The effect of surface roughness on friction and film thickness in transition from EHL to mixed lubrication. TRIBOLOGY INTERNATIONAL, 2018, vol. 128, no. 1, p. 356-364. ISSN: 1879-2464.
https://doi.org/10.1016/j.triboint.2018.07.047

KOŠŤÁL, D.; ŠPERKA, P.; SVOBODA, P.; KŘUPKA, I.; HARTL, M. Influence of lubricant inlet film thickness on EHL contact starvation. ASME Transaction, Journal of Tribology, 2017, vol. 139, no. 5, p. 1-10. ISSN: 0742-4787. https://doi.org/10.1115/1.4035777

HABCHI, W.; ŠPERKA, P.; BAIR, S. Is Elastohydrodynamic Minimum Film Thickness Truly Governed by Inlet Rheology?. Tribology Letters, 2023, vol. 71, no. 3, ISSN: 1023-8883. https://doi.org/10.1007/s11249-023-01771-y

Partners and Collaboration:
Daido Metal Czech s.r.o., Švédské valy 1309/6, 627 00 Brno, Czech Republic.

ZKL Výzkum a vývoj a.s., Jedovnická 2346/8, 628 00 Brno, Czech Republic.

JTEKT Bearings Czech Republic, Pavelkova 253/5, Bystrovany, 779 00 Olomouc, Czech Republic.

Robert Bosch GmbH, Robert-Bosch-Platz 1, 70839 Gerlingen-Schillerhöhe, Germany.

ENEOS corp., Yokohama, Japan.

Projects:
MEBioSys – Mechanical engineering of biological and bio-inspired systems, Johannes Amos Comenius programme, CZ.02.01.01/00/22_008/0004634, 2023-2028.

Thermohydrodynamic effects of boundary slip and surface texturing in sliding contacts, Czech Science Foundation – Standard grant projects, 22-29874S, 2022-2024.

Rheological properties of thin lubricating films in point contacts at transition to mixed lubrication, Czech Science Foundation – Standard grant projects, 21-28352S, 2021-2023

Thermo-Elastohydrodynamics of Coated Polymer Gears, Czech Science Foundation – international projects, GC18-26849J, 2018-2020.

Contact person:
Ing. Petr Šperka, Ph.D.