scholarly journals RESEARCH OF WORKING BENEFITS OF BEARINGS APPLICATION OF MATHEMATICAL METHOD

2021 ◽  
Vol 08 (04) ◽  
pp. 95-98
Author(s):  
Sevinc Abasova Sevinc Abasova
Keyword(s):  
Coefficient Of Friction ◽  
Thermoplastic Elastomer ◽  
Operating Parameters ◽  
Specific Load ◽  
Sliding Speed ◽  
Friction Units ◽  
Joint Influence ◽  
The Coefficient Of Friction ◽  
Heavy Loads ◽  
Main Operating

It is known that the service life of oilfield machines and mechanisms is to a certain extent determined by the operability of friction units, the operation of which, as a rule, occurs under severe conditions (heavy loads, abrasive aqueous medium, etc.). It is also known that the determining parameters in the units of machines and mechanisms (lubricated with water) with polymer elements are specific load, sliding speed and relative clearance. In the field, these factors affect the coefficient of friction together, therefore, the study of their influence [µ = f (p, ʋ, ψ)] on the coefficient of friction is possible only with the use of mathematical modeling. We have studied the nature of the joint influence of the main operating parameters on the performance of the ison thermoplastic elastomer plain bearings. Keywords: Operation, polymer elements, field conditions, bearings, sliding speed.

Paper 16: Friction in Wet Clutches

1967 ◽  
Vol 182 (14) ◽  
pp. 132-138 ◽  
Author(s):  
E. M. Evans ◽  
J. Whittle
Keyword(s):  
Coefficient Of Friction ◽  
Power Transmission ◽  
Sliding Speed ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Sliding Surfaces ◽  
Base Oils ◽  
Wet Friction ◽  
Friction Clutch ◽  
The Coefficient Of Friction

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants. A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.

Measurement of Tribological Parameters

2014 ◽  
Vol 875-877 ◽  
pp. 496-499 ◽  
Author(s):  
Eva Labašová ◽  
Rastislav Ďuriš
Keyword(s):  
Coefficient Of Friction ◽  
Test Equipment ◽  
Tribological Characteristics ◽  
Sliding Speed ◽  
Sliding Joint ◽  
The Coefficient Of Friction ◽  
Run Up ◽  
Tribological Parameters

The contribution deals with measurement of the coefficient of friction in the sliding joint. Rotanional sliding pair, which was tested, is described in this paper. Their tribological characteristics were measured by test equipment Tribotestor`89. The value of the coefficient of friction for the bushings from brass, aluminium and polyamide for chosen load (the sliding speed, loading, duration) are analysed in the paper. The largest decrease in the size of the coefficient of friction was recorded for bushings from aluminium, its value have decreased by 87.5% during the run up. Decrease of the coefficient of friction was recorded about 82% for bushings from brass and about 72% for bushings from polyamide. Run up lasted 10 minutes in all tests.

Friction of a Rubber Wedge Sliding on Glass

1991 ◽  
Vol 64 (1) ◽  
pp. 108-117 ◽  
Author(s):  
C. W. Extrand ◽  
A. N. Gent ◽  
S. Y. Kaang
Keyword(s):  
Coefficient Of Friction ◽  
Applied Load ◽  
Unit Length ◽  
Sliding Speed ◽  
Normal Loading ◽  
Contact Width ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Apparent Coefficient Of Friction ◽  
Pressure Independent

Abstract The contact width, and hence contact area, for an elastic wedge pressed against a rigid flat surface appears to be proportional to the applied load per unit length. For a particular rubber sample, the reciprocal of the constant of proportionality, i.e., the mean normal pressure, was 130 kPa, i.e., about 7% of the tensile modulus E of the material. It was also independent of sliding speed over the range examined. Thus, a sharp wedge gave a relatively high loading pressure, independent of the applied load. As a result, the coefficient of friction was also independent of applied load over a wide range. The coefficient of friction was measured for a wedge of an unfilled natural rubber vulcanizate over wide ranges of sliding speed (50 µm/s to 100 mm/s) and test temperature (3°C to 63°C). It was found to increase with sliding speed and decrease with temperature over these ranges. The results at different temperatures were superposable using the WLF rate-temperature equivalence to create a master curve of friction vs. reduced sliding speed, rising from a value of about 1.5 at high temperatures and low speeds to about 5 at low temperatures and high speeds. Chlorination of a thin surface region reduced the coefficient of friction and its dependence on speed and temperature. It then became similar to that typically found for thermoplastics, 0.4 to 0.7. The geometry of sliding a flexible strip against a rigid curved surface caused high values of the apparent coefficient of friction to be obtained at relatively small departures from normal loading. In an extreme case, frictional seizure was observed when a high-friction sample contacted the glass surface at an angle of about 15° to the direction of loading. The apparent coefficient of friction then became indefinitely large. This same phenomenon of abnormally large frictional effects would be expected to occur in the case of conventional windshield-wiper blades, sliding over curved glass windshields.

scholarly journals An experimental model to describe the temperature variation of the disk during braking tests

2012 ◽  
Vol 3 (3) ◽  
pp. 165-171
Author(s):  
P.D. Neis ◽  
G.L.P.G. Zanetti ◽  
E. Schmidt ◽  
Y. Perez Delgado ◽  
P. De Baets ◽  
...  
Keyword(s):  
Linear Regression ◽  
Statistical Model ◽  
Temperature Variation ◽  
Experimental Model ◽  
Coefficient Of Friction ◽  
Initial Temperature ◽  
Operating Parameters ◽  
Brake Pad ◽  
Mathematical Equation ◽  
The Coefficient Of Friction

In the present paper an experimental model is created to describe the temperature variation ofthe disk inexperiments performed on a laboratory-scale tribometer. A commercially available brake pad anddisk are used in the tests. The operating parameters seton the tribometer are a constant rotation of660 rpm, torque of 10Nm and 15Nm, braking time of 25s and 50s and initial temperature of 50°C and100°C. The evaluation of the thermal results is done by using a statistical model for analysis of variance(Anova). In order to obtain a mathematical equation to describe the temperature variation of the disk,a linear regression model is used. At the same time, the effect from both, temperature variation and initialtemperature, on the coefficient of friction are investigated.The effect of the temperature variation oncoefficient of friction is complex and it seems to not have correlation between them both. When the initialtemperature is changed from 50°C to 100°C the coefficient of friction is increased. The results from thecurrent paper shows that the experimental model can be used to predict the temperature variation of thedisk during braking tests performed on the tribometer.

Paper 19: Unlubricated Sliding at High Speeds between Copper and Steel Surfaces

1966 ◽  
Vol 181 (15) ◽  
pp. 25-30 ◽  
Author(s):  
M. J. Kadhim ◽  
S. W. E. Earles
Keyword(s):  
Oxide Layer ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Sliding Speed ◽  
Wear Rates ◽  
High Speeds ◽  
Before And After ◽  
The Coefficient Of Friction ◽  
Steel Disc ◽  
Steel Surfaces

Experiments are described in which stationary copper specimens are rubbed in a normal atmosphere against a rotating S62 steel disc under normal loads up to 4·5 lbf. The coefficient of friction is measured at sliding speeds of 93, 220, 328, and 490 ft/s using ⅛-in diameter specimens. Except at the lowest speed a gradual buildup of a continuous copper oxide layer on the disc track is observed with increasing normal load together with a corresponding decrease in the coefficient of friction. Having established an oxide layer on the track the coefficient of friction observed is low for all normal loads. The coefficient of friction is shown to decrease with normal load N and sliding speed U, to be a function of N1/2 U, and to depend on the state of the disc surface. Wear of -in diameter specimens is measured by weighing before and after a test. The wear rate is shown to decrease with sliding speed and increase with load, and for speeds of 220 and 328 ft/s to be a function of N/U. The wear rates measured at 93 ft/s are the same function of N/U for low values of N/U.

The Effect of Controlled Frequency and Amplitude of Vibration on Friction

2009 ◽  
Vol 147-149 ◽  
pp. 380-386 ◽  
Author(s):  
Jamil Abdo ◽  
Amer Al-Yhmadi
Keyword(s):  
Surface Roughness ◽  
Coefficient Of Friction ◽  
Nonlinear Function ◽  
Polynomial Equation ◽  
304 Stainless Steel ◽  
Sliding Speed ◽  
Pin On Disc ◽  
The Coefficient Of Friction ◽  
Friction Function ◽  
Alloy 6061

An in-house pin-on-disc apparatus is designed and constructed to perform the tests and the design of experiments technique is utilized to determine the effect of vibration, amplitude of vibration, surface roughness, and sliding speed and their cross influence on coefficient of friction for 304 stainless steel and Alloy 6061 Aluminum. The design is performed using response surface method (RSM). The coefficient of friction (CoF) is analyzed as a nonlinear function of the factors and predicted by a second-order polynomial equation. Results suggested that the presence of vibration affect the friction function CoF considerably for both metals. The friction function linearly decreases with the increases of vibration and amplitude of vibration, non-linearly decreases with the increases of sliding speed and linearly increases with the increases of the surface roughness until the middle range is reached and then there is non-linearly decrease thereafter. Similar trends of friction functions are observed for Alloy 6061 Aluminum with a reduction of almost 15% except for the case with amplitude of vibration where the variation showed more significant affect on the friction function when Alloy 6061 Aluminum disk is used.

Investigation of Vibration Induced by Sliding Down an Ice Plane

2019 ◽  
Vol 800 ◽  
pp. 298-302
Author(s):  
Mārtiņš Irbe ◽  
Marina Cerpinska ◽  
Karlis Agris Gross
Keyword(s):  
Coefficient Of Friction ◽  
High Sensitivity ◽  
Processing Conditions ◽  
Sliding Speed ◽  
Ice Surface ◽  
The Coefficient Of Friction

Many studies use an inclined ice plane to determine the effect of different materials and processing conditions on sliding over an ice surface. Experiments measure the sliding time at different stages on the track to determine the sliding speed and the coefficient-of-friction. Here, the sliding body vibrations and, the oscillations in axial directions are addressed. This paper analyzes the sample’s acceleration by attaching a portable High Sensitivity 1.25g USB Accelerometer and compares the data with 3D CAM modeling results to identify the causes for interrupted sliding.

scholarly journals MODELLING OF A GLASS GATHERER ROBOT'S ARM WITH A FRICTIONAL DAMPER

2018 ◽  
Vol 18 (4) ◽  
pp. 127-140
Author(s):  
Marek STEMBALSKI ◽  
Pawel PRES ◽  
Waclaw SKOCZYNSKI ◽  
Paweł TUREK
Keyword(s):  
Numerical Model ◽  
Finite Elements ◽  
Coefficient Of Friction ◽  
Normal Pressure ◽  
Operating Parameters ◽  
Sliding Velocity ◽  
Friction Damper ◽  
Damping Decrement ◽  
The Coefficient Of Friction ◽  
Contact Surfaces

A numerical model of a friction damper used for damping vibration in glass gatherer robots was described. The damper with a lance was modelled using finite elements. Primary natural frequency of the system was determined. Numerical calculations were performed to determine the best operating parameters of the damper for excitations using a impulse of a force. Results of the damping decrement calculations for the friction damper model with a constant coefficient of friction and for the model, in which the coefficient of friction varied depending on the sliding velocity and the normal pressure occurring at the contact surfaces of the damper’s friction rings, were presented. Based on numerical simulations, the values of relative displacements between the damper’s friction rings were also determined.

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