On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL Lubrication
This paper deals with an experimental study of film thickness and friction of commercial-grade grease and its base oil in a highly loaded contact. In-situ measurements were conducted for two surface textures on a ball-on-disc optical tribometer at the border of mixed lubrication. At high speeds, the...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-01-01
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| Series: | Lubricants |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4442/8/2/12 |
| _version_ | 1798035399488045056 |
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| author | Tomas Zapletal Petr Sperka Ivan Krupka Martin Hartl |
| author_facet | Tomas Zapletal Petr Sperka Ivan Krupka Martin Hartl |
| author_sort | Tomas Zapletal |
| collection | DOAJ |
| description | This paper deals with an experimental study of film thickness and friction of commercial-grade grease and its base oil in a highly loaded contact. In-situ measurements were conducted for two surface textures on a ball-on-disc optical tribometer at the border of mixed lubrication. At high speeds, the film thickness and the friction of grease correspond with the base oil, while, the thickener enters the contact area and locally affects the film thickness and friction at low speeds. It was found out that the thickener starts to enter the contact area approximately at the same speed when the base oil friction increases on Stribeck curve but without direct solid to solid contact. It indicates that both effects can have the same origin. Change of lubricant flow in contact inlet area was discussed as a possible explanation. |
| first_indexed | 2024-04-11T20:57:37Z |
| format | Article |
| id | doaj.art-b169855d4a964591969d34528b9d39a0 |
| institution | Directory Open Access Journal |
| issn | 2075-4442 |
| language | English |
| last_indexed | 2024-04-11T20:57:37Z |
| publishDate | 2020-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Lubricants |
| spelling | doaj.art-b169855d4a964591969d34528b9d39a02022-12-22T04:03:38ZengMDPI AGLubricants2075-44422020-01-01821210.3390/lubricants8020012lubricants8020012On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL LubricationTomas Zapletal0Petr Sperka1Ivan Krupka2Martin Hartl3Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno, Czech RepublicFaculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno, Czech RepublicFaculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno, Czech RepublicFaculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno, Czech RepublicThis paper deals with an experimental study of film thickness and friction of commercial-grade grease and its base oil in a highly loaded contact. In-situ measurements were conducted for two surface textures on a ball-on-disc optical tribometer at the border of mixed lubrication. At high speeds, the film thickness and the friction of grease correspond with the base oil, while, the thickener enters the contact area and locally affects the film thickness and friction at low speeds. It was found out that the thickener starts to enter the contact area approximately at the same speed when the base oil friction increases on Stribeck curve but without direct solid to solid contact. It indicates that both effects can have the same origin. Change of lubricant flow in contact inlet area was discussed as a possible explanation.https://www.mdpi.com/2075-4442/8/2/12film thicknessfrictiongreasebase oilehl |
| spellingShingle | Tomas Zapletal Petr Sperka Ivan Krupka Martin Hartl On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL Lubrication Lubricants film thickness friction grease base oil ehl |
| title | On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL Lubrication |
| title_full | On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL Lubrication |
| title_fullStr | On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL Lubrication |
| title_full_unstemmed | On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL Lubrication |
| title_short | On the Relation between Friction Increase and Grease Thickener Entraining on a Border of Mixed EHL Lubrication |
| title_sort | on the relation between friction increase and grease thickener entraining on a border of mixed ehl lubrication |
| topic | film thickness friction grease base oil ehl |
| url | https://www.mdpi.com/2075-4442/8/2/12 |
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