Functionality Investigations of Dry-Lubricated Molybdenum Trioxide Cylindrical Roller Thrust Bearings

Konopka, Dennis; Pape, Florian; Heimes, Norman; Behrens, Bernd‐Arno; Möhwald, Kai; Poll, Gerhard

doi:10.3390/coatings12050591

Cited by 4 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These particles could have then led to a groove that penetrated deeper into the coating, which would have increased the tangential force and thus the CoF. For solid lubrication, it is typical that at the same tribological load as the normal force and the sliding speed, there is a greater dispersion or spontaneous events in the course of the CoF [20]. Deeper penetration in combination with a high CoF can be observed for example in Figure 4a,b.…”

Section: Sliding Testsmentioning

confidence: 98%

“…In comparison, the uncoated reference only managed up to 40 min. After the tests, the uncoated cylindrical rollers had a transfer layer of Mo oxides, which was produced via transfer lubrication [20].…”

Section: Introductionmentioning

confidence: 99%

“…Based on the investigations of Konopka et al [20], the objectives of this work were to determine the influence of the sputter temperature on the hot hardness of the molybdenum layers and to investigate why the molybdenum layers were not completely consumed in the bearing test. For this purpose, Mo layers were deposited on hardened rolling bearing steel AISI 52,100 using PVD technology, whereby the substrate temperature was varied.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of the Hardness Development of Molybdenum Coatings under Thermal and Tribological Loading

et al. 2023

Self Cite

View full text Add to dashboard Cite

The increasing global demand for innovative and environmentally friendly lubricants can be met through the use of solid lubricants. By switching from conventional lubricants such as various oils or grease to solid lubricants, new scopes of application can also be opened up. The main requirements for solid lubricants are a reduction in the coefficient of friction (CoF) and an increase in wear resistance. Due to the favourable material properties, molybdenum (Mo) coatings fulfil the tribological requirements and are therefore promising solid lubricants which can be applied via physical vapour deposition (PVD). In this work, the impact of substrate temperature on the hot hardness of deposited Mo coatings was determined. The specimen with the highest hot hardness was then tribologically examined both at the micro and nano level. Through an analysis of the wear tracks by means of nanoindentation and scanning electron microscopy (SEM), it was possible to detect the influence of the tribological load separately from that of the thermal loads. The results showed that the tribological load influenced the Mo coating by significantly increasing its hardness. This was achieved due to the work hardening of the Mo layer leading to an increase in the wear resistance of the coating.

show abstract

Section: Sliding Testsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation of the Hardness Development of Molybdenum Coatings under Thermal and Tribological Loading

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Unlike graphite, MoS 2 performs well in oxygen-deficient environments, and its lubricative properties improve significantly (Donnet et al , 1996). Dennis et al (2022) investigated a newly developed coating system consisting of a combination of molybdenum and molybdenum trioxide in rolling element bearings under high mechanical loads to assess its lubrication effect and validate its adhesive and abrasive wear behavior in comparison with uncoated rolling bearings under dry contact conditions. Florian and Gerhard (2020) applied graphene platelets as dry lubricants and grease additives in machine elements, conducting tests on a rolling bearing test rig under typical load conditions.…”

Section: Introductionmentioning

confidence: 99%

Effect of composite solid lubricant coatings on the tribological performance of thrust cylindrical roller bearings

Xu,

Zhang

2023

ILT

View full text Add to dashboard Cite

Purpose This study aims to form composite solid lubricant coatings on the surface of bearing steel, which can significantly improve the tribological properties of thrust cylindrical roller bearings (TCRBs). Phosphating films possess microscopic porosity that typically needs to be sealed with oil, grease or wax. Due to its unique crystal structure, the phosphating film itself also exhibits a certain degree of lubricity. In this study, solid lubricants are used to fill the pores of the phosphating film. By combining the phosphating film with solid lubricants, lubrication and wear reduction can be achieved. Design/methodology/approach In this study, the surfaces of the shaft washer (WS) and seat washer (GS) were treated with zinc-phosphating. Subsequently, a solid lubricant solution (polytetrafluoroethylene [PTFE], MoS2 and graphite) was sprayed onto the phosphated samples at concentrations of 1 , 2 and 3 g/L. The porous and adsorptive nature of the phosphating film was used to embed the solid lubricant particles into the film, thus forming a composite lubrication layer containing solid lubricants on the surface of the bearing steel. Findings The addition of solid lubricant materials has shown significant potential in reducing wear losses compared with phosphated samples without such additives. Increasing the amount of solid lubricant added can facilitate the formation of a transfer film, which further enhances the protective properties. However, it is important to note that excessive amounts of solid lubricant material can contribute to seizure, leading to increased wear losses of the cage and a higher average coefficient of friction (ACOF).By spraying a PTFE solution with a concentration of 2 g/L, the lowest ACOF and cage wear loss were achieved, resulting in reductions of 60.5% for the ACOF and 89.4% for the cage wear loss. Similarly, when spraying a graphite solution with a concentration of 3 g/L, the lowest wear losses for GS and WS were observed, with reductions of 51.7% for GS wear loss and 38.9% for WS wear loss. Originality/value The combination of the phosphating film and solid lubricants aims to achieve lubrication and wear reduction, providing a new approach to wear-resistant technology for TCRBs. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2023-0231/

show abstract

“…Cylindrical roller bearing and raceway between line contact have the advantages of small friction torque, low friction loss, convenient lubrication, and maintenance, and they are widely used in aero-engine operation systems [1,2]. Relevant data show that the contact area lubrication failure is caused by the bearing and is the main reason for wear and failure.…”

Section: Introductionmentioning

confidence: 99%

Calculation and Lubrication Characteristics of Cylindrical Roller Bearing Oil Film with Consideration of Thermal Effects

Zhang

Guo

et al. 2022

Coatings

View full text Add to dashboard Cite

Aiming at the problem of how the thermal characteristics of cylindrical roller bearings affect the lubrication characteristics of bearings under actual working conditions, the influence of parameters such as speed and load on the lubrication characteristics of cylindrical roller bearings under thermal effects is analyzed. The numerical calculation method combining the quasi-static model of cylindrical roller bearing and the thermal elastohydrodynamic lubrication model is adopted. The effects of rotational speed, load and thermal effect on the lubrication performance of the bearing and the lubrication state under certain oil supply conditions were analyzed via numerical model calculation. The oil film thickness was measured via an immersion ultrasonic method to verify the correctness of the model. The results show that the larger the bearing speed, the larger the central film thickness and the minimum film thickness. At the same time, the thermal effect on the film thickness is more obvious; the greater the load, the greater the maximum oil film pressure. The film thickness gradient in the inlet region is greatly reduced, but the thermal effect has no obvious effect on the overall film thickness. In addition, there is a critical value of effective lubrication film thickness for each set of operating parameters. When the actual film thickness is equal to the critical value, the bearing lubrication state is at its best; the numerical simulation results are compared with the experimental values. Under the calculation conditions, the maximum error at the measuring point is within 10%, which meets the error requirements and provides a theoretical basis for revealing the bearing lubrication mechanism.

show abstract

Functionality Investigations of Dry-Lubricated Molybdenum Trioxide Cylindrical Roller Thrust Bearings

Cited by 4 publications

References 17 publications

Investigation of the Hardness Development of Molybdenum Coatings under Thermal and Tribological Loading

Investigation of the Hardness Development of Molybdenum Coatings under Thermal and Tribological Loading

Effect of composite solid lubricant coatings on the tribological performance of thrust cylindrical roller bearings

Calculation and Lubrication Characteristics of Cylindrical Roller Bearing Oil Film with Consideration of Thermal Effects

Contact Info

Product

Resources

About