Analysing the Tribological Behaviour of DLC-Coated Dry-Running Deep Groove Ball Bearings with Regard to the Ball Material

2016 ◽  
Vol 856 ◽  
pp. 143-150 ◽  
Author(s):  
Julia Kröner ◽  
Serge Kursawe ◽  
Yashar Musayev ◽  
Stephan Tremmel
Keyword(s):  
Carbon Films ◽  
Friction Torque ◽  
Ball Bearings ◽  
Tribological Behaviour ◽  
Functional Layer ◽  
Environmental Friendliness ◽  
Mineral Oils ◽  
Deep Groove ◽  
Friction Surfaces ◽  
Steel Substrates

In many applications conventional lubricants which are based on mineral oils cannot be used because it is physically impossible or forbidden by regulations. Operating machine elements, such as rolling element bearings, under dry running conditions is highly demanding in regard to the materials that are being used. Applying thin films to steel substrates was identified as an approach to achieve wear resistant and low friction surfaces at reasonable cost. Furthermore, a substitution of mineral oil based lubricants by coatings is an achievement in terms of sustainability, environmental friendliness and conserving resources. In this paper wear and friction behaviour of deep groove ball bearings with two types of diamond-like-carbon (DLC)coating systems on the inner and the outer ring are investigated. The coating systems are modified hydrogenated amorphous carbon films, one with a metallic doping element (a‑C:H:Me) functional layer and one with a non-metallic (a‑C:H:X). As ball materials hardened steel (100Cr6) and ceramics (Si3N4) are considered. The tests have been conducted on a four-bearing-test-rig under radial load and a constant rotational speed. The combination of a‑C:H:Me with Si3N4 balls shows the best results in this sample by reaching the predefined time limit without exhibiting an increase in the friction torque trend.

Friction Torque in Low Loaded Thrust Ball Bearings

2015 ◽  
Vol 809-810 ◽  
pp. 676-681
Author(s):  
Mihaela Rodica Balan ◽  
Ana Tufescu ◽  
Marcelin Benchea ◽  
Dumitru Olaru
Keyword(s):  
Axial Load ◽  
Ball Bearing ◽  
Friction Torque ◽  
Important Influence ◽  
Ball Bearings ◽  
Mineral Oils

The authors investigated experimentally the friction torque in a thrust ball bearing operating at very low axial load and lubricated with mineral oils. The experiments were conducted using spin-down methodology and the results were compared with the theoretical values determined by the SKF methodology for friction torque. The values of the friction torque obtained in the experiments are higher than the analytical values obtained with SKF equations, the differences being explained by the important influence of the friction in balls–cage contacts.

GreenBearings – Friction Behaviour of DLC-Coated Dry Running Deep Groove Ball Bearings

2015 ◽  
Vol 805 ◽  
pp. 147-153 ◽  
Author(s):  
Julia Kröner ◽  
Stephan Tremmel ◽  
Serge Kursawe ◽  
Yashar Musayev ◽  
Tim Hosenfeldt ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Energy Savings ◽  
Rolling Bearing ◽  
Friction Torque ◽  
Wear Behaviour ◽  
Ball Bearings ◽  
Rolling Bearings ◽  
Pumping Stations ◽  
Deep Groove ◽  
First Results

Due to the use of rolling bearings instead of plain bearings friction and wear are drastically reduced in all kind of machines. However, despite the high technical standard of modern rolling bearings there is still a significant potential for optimization. Preliminary Studies show a reduction of the friction torque of up to 44 % compared to conventional rolling bearings because of the use of tribological coatings in certain applications. Based on the millionfold usage of rolling bearings in all industrial fields the reduced lost energy adds up to a remarkable potential for energy savings. If friction and wear are lowered sufficiently, the use of conventional lubricants based on mineral oil can be successively decreased or even completely avoided. In the latter case, the socalled dry running of the rolling bearing, the energy consumption of machines and systems can additionally be reduced significantly. For example, pumping stations or compressed air units, which would be necessary for transporting or spraying the lubricants, can then be saved.This paper presents first results of DLC-coated deep groove ball bearings, which are tested in a four-bearing-test-rig under purely radial load with respect to their friction and wear behaviour.

Experimental Vibration Studies of Deep Groove Ball Bearings Having Damaged Surfaces

2018 ◽  
Vol 100 (6) ◽  
pp. 919-935 ◽  
Author(s):  
Dipen S. Shah ◽  
V. N. Patel ◽  
Pranav H. Darji
Keyword(s):  
Ball Bearings ◽  
Deep Groove

scholarly journals STUDY OF EFFECT OF SOLID CONTAMINANTS IN THE LUBRICANT ON BALL BEARINGS VIBRATION

2012 ◽  
pp. 28-31
Author(s):  
ONKAR L. MAHAJAN ◽  
ABHAY A. UTPAT
Keyword(s):  
Experimental Tests ◽  
Solid Particles ◽  
Particle Sizes ◽  
Ball Bearings ◽  
Bearing Failure ◽  
Mean Square ◽  
Rolling Bearings ◽  
Vibration Signals ◽  
Deep Groove ◽  
Concentration Levels

In deep groove ball bearings contamination of lubricant grease by solid particles is one of the main reason for early bearing failure. To deal with such problem, it is fundamental not only the use of reliable techniques concerning detection of solid contamination but also the investigation of the effects of certain contaminant characteristics on bearing performance. Nowadays the techniques such as vibration measurements are being increasingly used for on-time monitoring of machinery performance. The present work investigates the effect of lubricant contamination by solid particles on the dynamic behavior of rolling bearings, in order to determine the trends in the amounts of vibration affected by contamination in the Grease and by the bearing wear itself. Experimental tests are performed with Deep-groove ball bearings. The Dolomite powder in three concentration levels and different particle sizes was used to contaminate the grease. Vibration signals were analyzed in terms of Root Mean Square (RMS) values and also in terms of defect frequencies.

Study of MoS2-Ti Composite Coatings Applied in Precision Ball Bearings

2012 ◽  
Vol 538-541 ◽  
pp. 281-285
Author(s):  
Hui Zhou ◽  
Jun Zheng ◽  
Ji Xing Hu ◽  
Rui Peng Sang ◽  
Zhi Hua Wan
Keyword(s):  
Storage Time ◽  
Performance Test ◽  
Composite Coatings ◽  
Test Chamber ◽  
Friction Torque ◽  
Solid Lubrication ◽  
Ball Bearings ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
High Humidity Environment

708C Ball bearings were made of 9Cr18 steel which had precision of class 4, MoS2-Ti composite coatings were deposited on inner and outer races of ball bearings by unbalanced magnetron sputtering system, and bearing cages were made of PTFE-based self-lubricating polymers. Bearing’s tribological torques as a function of storage time in high humidity environment were studied by using LHU-2 thermal & humidity test chamber and Bearing 2000 torque measurement device. Developing bearing vacuum performance test rig to research bearing’s torque as a function of running time, bearings were dismantled after test and using XPS to analyze the surfaces of bearing’s races and balls. The results show that storied in the environment of 30°C, 85% RH, bearing’s running torques increased proportionally as the storage time went on. When run-in the bearings which were storied for 440 days, the start and average running torques of bearings could come back to the level which was the same as the test start, but the fluctuation of bearing’s average running torque increased. Running in one direction at the speed of 650 r/min, in vacuum environment (~10-4Pa) and ambient temperature, tested bearings showed good running performance with low friction torque varied only between 1g·cm~2 g·cm until to the test ended at 1.872×108 revolutions. XPS analysis showed that a stable and sustainable solid lubrication system was established among bearing’s races, balls and cages.

Sign in / Sign up

Export Citation Format

Share Document