Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance Thermoplastics

Thermoplastics show great potential due to their lightweight design, low-noise operation, and cost-effective manufacturing. Oil lubrication allows for their usage in high-power-transmission applications, such as gears. The current design guidelines for thermoplastic gears lack reliable estimates for...

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Main Authors: Ferdinand Schmid, Thomas Lohner, Karsten Stahl
Format: Article
Language:English
Published: MDPI AG 2024-10-01
Series:Lubricants
Subjects:
Online Access:https://www.mdpi.com/2075-4442/12/11/372
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author Ferdinand Schmid
Thomas Lohner
Karsten Stahl
author_facet Ferdinand Schmid
Thomas Lohner
Karsten Stahl
author_sort Ferdinand Schmid
collection DOAJ
description Thermoplastics show great potential due to their lightweight design, low-noise operation, and cost-effective manufacturing. Oil lubrication allows for their usage in high-power-transmission applications, such as gears. The current design guidelines for thermoplastic gears lack reliable estimates for the coefficient of friction of oil-lubricated rolling–sliding contacts. This work characterizes the friction of elastohydrodynamic rolling–sliding contacts with technical and high-performance thermoplastics with oil lubrication. The influence of polyoxymethylene (POM), polyamide 46 (PA46), polyamide 12 (PA12), and polyetheretherketone (PEEK), as well as mineral oil (MIN), polyalphaolefin (PAO), and water-containing polyalkylene glycol (PAGW), was studied. Experiments were carried out on a ball-on-disk tribometer, considering different loads, speeds, temperatures, and surface roughness. The results show that, for fluid film lubrication, there is very low friction in the superlubricity regime, with a coefficient of friction lower than 0.01. Both sliding and rolling friction account for a significant portion of the total friction, depending on the contact configuration and operating conditions. In the mixed to boundary lubrication regime, the sliding friction depends on the thermoplastic and rises sharply, thus increasing the total friction.
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spelling doaj-art-25a6252bbbfd43a7a5727c8f6b7464172025-08-20T01:53:57ZengMDPI AGLubricants2075-44422024-10-01121137210.3390/lubricants12110372Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance ThermoplasticsFerdinand Schmid0Thomas Lohner1Karsten Stahl2Gear Research Center (FZG), Department of Mechanical Engineering, School of Engineering and Design, Technical University of Munich, Boltzmannstraße 15, D-85748 Garching, GermanyGear Research Center (FZG), Department of Mechanical Engineering, School of Engineering and Design, Technical University of Munich, Boltzmannstraße 15, D-85748 Garching, GermanyGear Research Center (FZG), Department of Mechanical Engineering, School of Engineering and Design, Technical University of Munich, Boltzmannstraße 15, D-85748 Garching, GermanyThermoplastics show great potential due to their lightweight design, low-noise operation, and cost-effective manufacturing. Oil lubrication allows for their usage in high-power-transmission applications, such as gears. The current design guidelines for thermoplastic gears lack reliable estimates for the coefficient of friction of oil-lubricated rolling–sliding contacts. This work characterizes the friction of elastohydrodynamic rolling–sliding contacts with technical and high-performance thermoplastics with oil lubrication. The influence of polyoxymethylene (POM), polyamide 46 (PA46), polyamide 12 (PA12), and polyetheretherketone (PEEK), as well as mineral oil (MIN), polyalphaolefin (PAO), and water-containing polyalkylene glycol (PAGW), was studied. Experiments were carried out on a ball-on-disk tribometer, considering different loads, speeds, temperatures, and surface roughness. The results show that, for fluid film lubrication, there is very low friction in the superlubricity regime, with a coefficient of friction lower than 0.01. Both sliding and rolling friction account for a significant portion of the total friction, depending on the contact configuration and operating conditions. In the mixed to boundary lubrication regime, the sliding friction depends on the thermoplastic and rises sharply, thus increasing the total friction.https://www.mdpi.com/2075-4442/12/11/372polymerthermoplasticelastohydrodynamic lubricationfrictionsuperlubricitytribology
spellingShingle Ferdinand Schmid
Thomas Lohner
Karsten Stahl
Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance Thermoplastics
Lubricants
polymer
thermoplastic
elastohydrodynamic lubrication
friction
superlubricity
tribology
title Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance Thermoplastics
title_full Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance Thermoplastics
title_fullStr Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance Thermoplastics
title_full_unstemmed Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance Thermoplastics
title_short Friction in Oil-Lubricated Rolling–Sliding Contacts with Technical and High-Performance Thermoplastics
title_sort friction in oil lubricated rolling sliding contacts with technical and high performance thermoplastics
topic polymer
thermoplastic
elastohydrodynamic lubrication
friction
superlubricity
tribology
url https://www.mdpi.com/2075-4442/12/11/372
work_keys_str_mv AT ferdinandschmid frictioninoillubricatedrollingslidingcontactswithtechnicalandhighperformancethermoplastics
AT thomaslohner frictioninoillubricatedrollingslidingcontactswithtechnicalandhighperformancethermoplastics
AT karstenstahl frictioninoillubricatedrollingslidingcontactswithtechnicalandhighperformancethermoplastics