scholarly journals Investigation of the effective parameters of scuffing failure in gears

Author(s):  
Mehmet Bozca ◽  

This study investigates the effective parameters of scuffing failure in gears using the integral temperature method. For this aim, the mass temperature, integral temperature and scuffing safety factor are calculated for a given parameters. Then, integral temperatures are simulated based on various geometrical, operational and lubrication parameters. Obtained results are presented graphically. The obtained results show that increasing the module mn results in a decrease in the integral temperature ϑint. Similarly, increasing the pinion teeth number zp results in a decrease in the integral temperature ϑint. Increasing the module and tooth number positively affects the scuffing failure in gears. In contrast, increasing the transmitted torque MT1T results in an increase in the integral temperature ϑint. Similarly, increasing the pinion speed np increases the mass temperature ϑM, and increasing the lubricant (oil) ϑÖ temperature increases the integral temperature ϑint. Increasing the transmitted torque, lubricant temperature and the pinion speed negatively affects the scuffing failure in gears. Finally, increasing the nominal kinematic viscosity v40 decreases the integral temperature ϑint. Increasing the nominal kinematic viscosity positively affects the scuffing failure in gears. By considering the effective parameters of scuffing failure such as geometrical, operational and lubrication, one can design and manufacture the desired gears without scuffing failure.

Author(s):  
Dini Kurniawati ◽  
Iis Siti Aisyah

Jatropha curcas oil is a seed oil or bio-oil, which has advantages compared to others plant’s seed-oil.  The advantage of this oil is due to the fact that Jatropha oil does not compete with the food sector. In this research, the potential carrier oil testing was conducted to seek a way in improving the performance of Jatropha oil as lubricant oil, coolant or biodiesel. For this purpose, Jatropha oil was mixed with the other carrier oils in the variation of 0 – 45 %. Each variation was tested to obtain kinematic viscosity and density values. The results of this research was the carrier oils has the potential to be used as the mixing material since it can improve the physical properties of Jatropha oil, before the next process. Kinematic viscosity and density of Jatropha oil decreases as more percentage of mixed carrier oil was added.


Lubricants ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 94
Author(s):  
Bahaa M. Kamel ◽  
Vineet Tirth ◽  
Ali Algahtani ◽  
Mohamed S. Shiba ◽  
Ahmed Mobasher ◽  
...  

The augmentation of lubricant oil properties is key to protecting engines, bearings, and machine parts from damage due to friction and wear and minimizing energy lost in countering friction. The tribological and rheological properties of the lubricants are of utmost importance to prevent wear under unembellished conditions. The marginal addition of particulate and filamentous nanofillers enhances these properties, making the lubricant oil stable under severe operating conditions. This research explores the improvement in SAE 5w-30 base oil performance after the addition of multiwalled carbon nanotubes (MWCNTs) in six marginal compositions, namely, Base, 0.02, 0.04, 0.06, 0.08, and 0.10 weight percentage. The effect of the addition of MWCNTs on flash and pour points, thermal conductivity, kinematic viscosity, friction coefficients, and wear are investigated and reported. X-ray diffraction and transmission electron microscopy are used to characterize the MWCNTs. The purity, crystallinity, size, shape, and orientation of the MWCNTs are confirmed by XRD and TEM characterization. Pour points and flash points increase by adding MWCNTs but inconsistency is observed after the 0.06 wt.% composition. The thermal conductivity and kinematic viscosity increase significantly and consistently. The friction coefficient and wear scar diameter reduce to 0.06 wt.% MWCNTs and then the trend is reversed due to agglomeration and inhomogeneity. A composition of 0.06 wt.% is identified as the optimum considering all the investigated properties. This composition ensures the stability of the tribo-film and hydrodynamic lubrication.


2020 ◽  
Vol 13 (6) ◽  
pp. 235-240
Author(s):  
Hamed Bagheri ◽  
Reza Reiazi ◽  
Mohammad Kasaie ◽  
Hosein Mootabian

AbstractBackgroundAtmospheric plasma jet has different medical applications due to its low temperature at room temperature. In recent years, the effect of nonthermal plasmas on cancer cells has been studied, and it has been shown that this type of plasma has anti-proliferative effects on cancer cells.ObjectivesTo design a plasma jet handpiece, which can be used in cutting operations in less bleeding surgery, eliminating cancer cells without damage to healthy cells and reducing the duration of wound healing.MethodsThe plasma handpiece simply consists of a nozzle body and two cathode and anode electrodes and a fully insulated body against heat and high voltage. Argon is introduced into the handpiece, and by plasma treatment, it is used for special purposes. Each piece was made according to its own manufacturing process and by assembling; the final product of the atmospheric plasma jet handpiece was ready for testing. The jet pipeline was then tested, and the effective parameters were examined.ResultsThe cold atmospheric plasma jet length depends on factors such as power supply, applied voltage, gas flow rate and the distance between the electrodes. The results showed with increasing velocity, the flame and jet lengths decreased greatly due to high losses of plasma, including ions and electrons. Also with increasing the velocity of argon gas, its concentration decreased.ConclusionsIt is concluded that the performance of the proposed design is successful. The advantages include low-cost manufacturing, highly stable performance, and low erosion and can be considered for future development.


2020 ◽  
Vol 21 (5) ◽  
pp. 505
Author(s):  
Yousef Ghaderi Dehkordi ◽  
Ali Pourkamali Anaraki ◽  
Amir Reza Shahani

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.


Author(s):  
Oleg V. Aralov ◽  
◽  
Ivan V. Buyanov ◽  
Anton S. Savanin ◽  
Evgeny I. Iordansky ◽  
...  

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