Scientific research, educational and other activities on ÚK

Transcription

1 Scientific research, educational and other activities on ÚK Martin Zimmerman 7th November 212, FME BUT, Czech republic 1/16

2 film thickness, nm film thickness, nm Previous results T = 23 C HPO2 =.69 Pa s; HPO2 = 19 GPa -1 roughness:.3 µm;.18 µm texture:.6 µm; 35 µm speed mm*s radius, µm time ms radius, µm 7th November 212, FME BUT, Czech republic 2/16

3 Conclusions no.1 At moment of zero entrainment speed no film rupture was observed for any type of surface. Rupture of lubricating film occurs only in case when polished steel ball surface was used. Micro-dents working as lubricant micro-reservoirs that reduce asperity interaction. More effective separation of rubbing surfaces will be obtained in case of triangular distribution of microdents. Aim of following study What effect has the simultaneous change of load and speed of contact surfaces on the behavior of the lubricating film in EHL contact? 7th November 212, FME BUT, Czech republic 3/16

4 Experimental apparatus reduction of moving masses monitoring of contact load and speed of contact surfaces during the experiment possibility to change the two operating parameters (load and speed) lubricant HPO2 T = 23 C =.69 Pa s = 19 GPa -1 steel ball, glas disc 7th November 212, FME BUT, Czech republic 4/16

5 Results and discussion constant load 1) Constant load Dynamic speed,9,8,7 speed, m s -1,6,5,4,3,2,1 -,1 -, ball disc entrain. 7th November 212, FME BUT, Czech republic 5/16

6 thickness, nm thickness, nm thickness, nm thickness, nm Results and discussion constant load hcent hmin 15 1 hcent hmin 5 1 N 5 2 N hcent 15 hcent hmin 1 hmin 3 N 5 4 N th November 212, FME BUT, Czech republic 6/16

7 film thickness, nm film thickness, nm Results and discussion constant load speed, m s -1,9,8,7,6,5,4,3,2,1 -,1 -,2 4 N A D B C ball disc entrain initial load, N hcent_a hcent_d hmin_a hmin_d 25 3 N 2 2 N hcent_b hmin_b hcent_c hmin_c 1 N A B C D initial load, N 7th November 212, FME BUT, Czech republic 7/16

8 speed, m/s load, N loading force, N Results and discussion variable load 2) Variable load Dynamic speed 1 7 9, ball disc entrainment load,6,4, N 2 N 3 N 4 N ,2 7th November 212, FME BUT, Czech republic 8/16

9 thickness, nm thickness, nm thickness, nm thickness, nm Results and discussion variable load hcent hmin 15 1 hcent hmin 5 1 N 5 2 N hcent hcent hmin 1 hmin 3 N 5 4 N th November 212, FME BUT, Czech republic 9/16

10 film thickness, nm film thickness, nm Results and discussion variable load speed, m s -1,9,8,7,6,5,4,3,2,1 -,1 -,2 4 N A D B C ball disc entrain initial load, N hcent_a hcent_d hmin_a hmin_d 3 N 2 15 hcent_b 2 N 1 5 hmin_b hcent_c hmin_c 1 N A B C D initial load, N 7th November 212, FME BUT, Czech republic 1/16

11 Results and discussion variable load Constant load Dynamic load 4 N 3 N 2 N 1 N A B C D A B C D 7th November 212, FME BUT, Czech republic 11/16

12 Conclusions no.2 For critical parts of the cycle has been experimentally demonstrated the independence of the lubricating film thickness on loading force and type of loading. The film thickness at higher speeds is affected by loading force. At moment of zero entrainment speed no film rupture was observed. Future interests modifications of the experimental apparatus in order to increase the stiffness of the system for research of impact load influence on film thickness bahavior biotribology 7th November 212, FME BUT, Czech republic 12/16

13 Science and research Projects GAČR J - Study of the effects of surface pattern structures on the transient elastohydrodynamic film formation. GAČR P Experimental study of lubrication film formation under starved conditions HS Měření axiálních sil ve šroubech HS Posudek na šroubový spoj včetně výpočtu Publication ZIMMERMAN, M.; KŘUPKA, I.; HARTL, M.; HOUŠKA, P. Effect of surface texturing on EHD lubrication films under transient speed condition. Los Angeles: ASME/STLE International Joint Tribology Conference, 211, pp ISBN ZIMMERMAN, M.; KŘUPKA, I.; HARTL, M.; HOUŠKA, P. Lubrication film thickness behavior under transient speed and load conditions. Denver: ASME/STLE International Joint Tribology Conference, 212, pp ISBN th November 212, FME BUT, Czech republic 13/16

14 Education management of e-learning system for following subjects: 5KS Konstruování strojů - strojní součásti ZKP Konstrukční projekt ZTR Tribologie leadership of theses bachelor thesis 1x diploma thesis 2x 7th November 212, FME BUT, Czech republic 14/16

15 Other activities 7th November 212, FME BUT, Czech republic 15/16

16 Thank you for your attention M. Zimmerman 7th November 212, FME BUT, Czech republic