scholarly journals Evaluation of Flushed Oil with Respect to New Oil

2021 ◽  
Author(s):  
Maitham Al-Safwani
Keyword(s):  
Life Span ◽  
Friction Force ◽  
Bearing Failure ◽  
Bearing Life ◽  
Bearing Load ◽  
Lubrication Oil ◽  
Cleaning Methods ◽  
The Impact ◽  
Paper Address

<p><i>The paper address the tests required to be conducted for lubrication oil. It investigates the change of properties of new oil after it is being used for flushing. The recommendations of changing flushed oil or keeping it made on different analysis and studies, however, if the oil properties are not changing, then using the flushed oil is recommended as the new oil will not be as clean as flushed oil. The paper listed several oil cleaning methods and highlighted several causes which could result on bearing failure. The bearing lifetime was discussed and how the impact of different parameter could impact the bearing life span if it is generating additional forces, for example, due to the increase of friction force which contribute to the equivalent dynamic bearing load. </i></p>

scholarly journals Evaluation of Flushed Oil with Respect to New Oil

2021 ◽  
Author(s):  
Maitham Al-Safwani
Keyword(s):  
Life Span ◽  
Friction Force ◽  
Bearing Failure ◽  
Bearing Life ◽  
Bearing Load ◽  
Lubrication Oil ◽  
Cleaning Methods ◽  
The Impact ◽  
Paper Address

<p><i>The paper address the tests required to be conducted for lubrication oil. It investigates the change of properties of new oil after it is being used for flushing. The recommendations of changing flushed oil or keeping it made on different analysis and studies, however, if the oil properties are not changing, then using the flushed oil is recommended as the new oil will not be as clean as flushed oil. The paper listed several oil cleaning methods and highlighted several causes which could result on bearing failure. The bearing lifetime was discussed and how the impact of different parameter could impact the bearing life span if it is generating additional forces, for example, due to the increase of friction force which contribute to the equivalent dynamic bearing load. </i></p>

scholarly journals Evaluation of Flushed Oil with Respect to New Oil

2021 ◽  
Author(s):  
Maitham Al-Safwani
Keyword(s):  
Life Span ◽  
Friction Force ◽  
Bearing Failure ◽  
Bearing Life ◽  
Bearing Load ◽  
Lubrication Oil ◽  
Cleaning Methods ◽  
The Impact ◽  
Paper Address

<p><i>The paper address the tests required to be conducted for lubrication oil. It investigates the change of properties of new oil after it is being used for flushing. The recommendations of changing flushed oil or keeping it made on different analysis and studies, however, if the oil properties are not changing, then using the flushed oil is recommended as the new oil will not be as clean as flushed oil. The paper listed several oil cleaning methods and highlighted several causes which could result on bearing failure. The bearing lifetime was discussed and how the impact of different parameter could impact the bearing life span if it is generating additional forces, for example, due to the increase of friction force which contribute to the equivalent dynamic bearing load. </i></p>

scholarly journals Risk factors for physical inactivity across the adult life span: the impact of depression

2006 ◽  
Vol 18 (6) ◽  
pp. 274-274
Author(s):  
J Walker ◽  
H Christensen ◽  
T Windsor ◽  
A George
Keyword(s):  
Risk Factors ◽  
Life Span ◽  
Physical Inactivity ◽  
Adult Life ◽  
Adult Life Span ◽  
The Impact

The Impact of Invisible Illness on Identity and Contextual Age Across the Life Span

2003 ◽  
Vol 15 (3) ◽  
pp. 331-347 ◽  
Author(s):  
Amanda L. Kundrat ◽  
Jon F. Nussbaum
Keyword(s):  
Life Span ◽  
The Impact

Low Temperature Pre-Epi Treatment: Critical Parameters to Control Interface Contamination

2009 ◽  
Vol 145-146 ◽  
pp. 177-180 ◽  
Author(s):  
Roger Loo ◽  
Andriy Hikavyy ◽  
Frederik E. Leys ◽  
Masayuki Wada ◽  
Kenichi Sano ◽  
...  
Keyword(s):  
Low Temperature ◽  
Sige Layer ◽  
Ex Situ ◽  
Critical Parameters ◽  
Process Equipment ◽  
Successful Implementation ◽  
Lifetime Measurements ◽  
Deposition Processes ◽  
Cleaning Methods ◽  
The Impact

Several device concepts have been further evaluated after the successful implementation of epitaxial Si, SiGe and/or Si:C layers. Most of the next device generations will put limitations on the thermal budget of the deposition processes without making concessions on the epitaxial layer quality. In this work we address the impact of ex-situ wet chemical cleans and in-situ pre-epi bake steps, which are required to obtain oxide free Si surfaces for epitaxial growth. The combination of defect measurements, Secondary Ion Mass Spectroscopy, photoluminescence, lifetime measurements, and electrical diode characterization gives a very complete overview of the performance of low-temperature pre-epi cleaning methods. Contamination at the epi/substrate interface cannot be avoided if the pre-epi bake temperature is too low. This interface contamination is traceable by the photoluminescence and lifetime measurements. It may affect device characteristics by enhanced leakage currents and eventually by yield issues due to SiGe layer relaxation or other defect generation. A comparison of state of the art 200 mm and 300 mm process equipment indicates that for the same thermal budgets the lowest contamination levels are obtained for the 300 mm equipments.

scholarly journals Influence of the Lubrication Oil Temperature on the Disengaging Dynamic Characteristics of a Cu-Based Wet Multi-Disc Clutch

2021 ◽  
Vol 11 (23) ◽  
pp. 11299
Author(s):  
Liangjie Zheng ◽  
Biao Ma ◽  
Man Chen ◽  
Liang Yu ◽  
Qian Wang
Keyword(s):  
Dynamic Characteristics ◽  
Hydrodynamic Lubrication ◽  
Friction Pair ◽  
Automatic Transmission ◽  
Friction Torque ◽  
Asperity Contact ◽  
Uniformity Coefficient ◽  
Lubrication Oil ◽  
The Impact ◽  
First Time

Clutch disengaging dynamic characteristics, including the disengaging duration and the variations of friction pair gaps and friction torque, are crucial to the shifting control of an automatic transmission. In the present paper, the influence of lubrication oil (ATF) temperature on disengaging dynamic characteristics is investigated through a comprehensive numerical model for the clutch disengaging process, which considers the hydrodynamic lubrication, the asperity contact, the heat transfer, the spline resistance, and the impact between the piston and clutch hub. Moreover, the non-uniformity coefficient (NUC) is proposed to characterize the disengaging uniformity of friction pairs. As the ATF temperature increases from 60 °C to 140 °C, the clutch disengaging duration shortens remarkably (shortened by 55.1%); besides, the NUC sees a decreasing trend before a slight increase. When the ATF temperature is 80 °C, the distribution of friction pair gaps is most uniform. During the disengaging process, the increase of ATF temperature not only accelerates the change of the lubrication status between friction pairs but also contributes to the decrease of contact torque and hydrodynamic torque. This research demonstrates for the first time, evidence for clutch disengaging dynamic characteristics with the consideration of ATF temperature.

Rolling Element Bearing Non-Linearity Effects

2000 ◽  
Author(s):  
N. S. Feng ◽  
E. J. Hahn
Keyword(s):  
Equations Of Motion ◽  
Rolling Element Bearing ◽  
Radial Clearance ◽  
Rotor Systems ◽  
Bearing Life ◽  
Rolling Element ◽  
Bearing Load ◽  
Rolling Elements ◽  
Element Bearing ◽  
Negative Clearance

Non-linearity effects in rolling element bearings arise from two sources, viz. the Hertzian force deformation relationship and the presence of clearance between the rolling elements and the bearing races. Assuming that centrifugal effects may be neglected and that the presence of axial preload is appropriately reflected in a corresponding change in the radial clearance, this paper analyses a simple test rig to illustrate that non-linear phenomena such as synchronous multistable and nonsynchronous motions are possible in simple rigid and flexible rotor systems subjected to unbalance excitation. The equations of motion of the rotor bearing system were solved by transient analysis using fourth order Runge Kutta. Of particular interest is the effect of clearance, governed in practice by bearing specification and the amount of preload, on the vibration behaviour of rotors supported by ball bearings and on the bearing load. It is shown that in the presence of positive clearance, there exists an unbalance excitation range during which the bearing is momentarily not transmitting force owing to contact loss, resulting in rolling element raceway impact with potentially relatively high bearing forces; and indicating that for long bearing life, operation with positive clearance should be avoided in the presence of such unbalance loading. Once the unbalance excitation is high enough to avoid such contact loss, it is the bearings with zero or negative clearance which produce maximum bearing forces.

scholarly journals Mathematical Modeling of Impact of Possible Shock Dynamic Loads on the Modern Composite Materials

2019 ◽  
Vol 224 ◽  
pp. 02012
Author(s):  
Eugenе Sosenushkin ◽  
Oksana Ivanova ◽  
Elena Yanovskaya ◽  
Yuliya Vinogradova
Keyword(s):  
Composite Materials ◽  
Friction Force ◽  
Equations Of Motion ◽  
Elastic Fiber ◽  
Dynamic Loads ◽  
Friction Forces ◽  
Absolute Value ◽  
A Value ◽  
The Absolute ◽  
The Impact

In this paper, we study the dynamic processes in materials reinforced with fibers, that can be represented as composite rods. There has been developed a mathematical model of wave propagation under the impact of a shock pulse in semi-infinite composite rods. It is believed that the considered composite rod consists of two layers formed by simpler rods of different isotropic materials with different mechanical properties. The cross sections of such rods are considered to be constant and identical. When such composite materials are impacted by dynamic loads, a significant part of the energy is dissipated due to the presence of friction forces between the contact surfaces of the rods. In this regard, we study the propagation of waves in an elastic fiber-rod, the layers of which interact according to Coulomb law of dry friction. The case of instantaneous excitation of rods by step pulses is investigated. The blow is applied to a rod made of a harder material. In the absence of slippage, the friction force gets a value not exceeding the absolute value of the limit. In the absence of slippage, the friction force takes a value not exceeding the absolute value of the limit. Let us consider the value of the friction force constant. Normal stresses and velocities satisfy the equations of motion and Hooke’s law. The problem statement results in the solution of inhomogeneous wave equations by the method of characteristics in different domains, which are the lines of discontinuities of the solution. Solutions are found in all constructed domains. On the basis of the analysis of the obtained solution, qualitative conclusions are made and curves are constructed according to the obtained ratios. From the found analytical solution of the problem it is possible to obtain ratios for stresses and strain rates in composite rods and composite materials.

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