Study of variation patterns in sliding friction coeffi cient in innovative methods of combined hole mandrelling

2020 ◽  
pp. 150-155
Author(s):  
A.V. Shchedrin ◽  
I.Yu. Ignatkin ◽  
N.Yu. Chikhacheva
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Scientific Discovery ◽  
Friction Theory ◽  
Innovative Methods ◽  
Variation Patterns ◽  
Sliding Friction Coefficient ◽  
Theoretical Foundations

The variation patterns of sliding friction coefficient in innovative methods of hole mandrelling by regular microrelief tool of the working surfaces under the conditions of using modern metal plaque lubricants, which implement the fundamental scientific discovery "Garkunov—Kragelsky frictionlessness effect", are studied using the theoretical foundations of the adhesion-deformation friction theory.

scholarly journals DESCRIPTIVE MODEL OF SLIDING FRICTION PROCESSES

2015 ◽  
Vol 2 ◽  
pp. 227
Author(s):  
Andris Martinovs ◽  
Vladimir Gonca
Keyword(s):  
Friction Coefficient ◽  
Surface Area ◽  
Contact Surface ◽  
Sliding Friction ◽  
Friction Model ◽  
Friction Process ◽  
Contact Surface Area ◽  
Optimal Surface ◽  
Sliding Friction Coefficient ◽  
The Mathematical Model

Paper analyses the sliding friction coefficient of rubber on concrete, timber and ceramic tile surfaces depending on the weight of the sliding object and contact surface area. It has been established that increase in the weight of the object makes sliding friction coefficient to grow. In the case of increase in size of contact area, sliding friction coefficient between rubber and concrete also increases, but it decreases between rubber- timber and rubber- tile. The mathematical model for description of sliding friction process has been developed which can be used to determine optimal surface area and a pattern as well as optimal weight of the sliding object in order to provide sufficient sliding friction. Model has five independent constants. It includes the contact surface area, the weight and the velocity of the sliding object, sliding friction coefficient, temperature and time.

Research on Dynamic Model of Double Helical Gear Pair Based on TCA and LTCA

2019 ◽  
Vol 24 (3) ◽  
pp. 476-484 ◽  
Author(s):  
Cheng Wang ◽  
Shouren Wang ◽  
Gaoqi Wang
Keyword(s):  
Friction Coefficient ◽  
Dynamic Model ◽  
Dynamic Models ◽  
Sliding Friction ◽  
Helical Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Axial Vibration ◽  
Sliding Friction Coefficient ◽  
Helical Gear Pair

Numerous dynamic models of spur gears, helical gears, bevel gears, and face gears can be found in various studies. However, studies that focus on the dynamic model of a double helical gear pair are quite limited. The author proposed a model of a double helical gear pair by only considering the axial vibration. The author did not consider the friction and multiple backlashes in the proposed model. The friction force of the tooth surface and backlash are important factors that can cause complex non-linear phenomena in gear pairs. Therefore, a dynamic model of a double helical gear pair that takes into consideration the axial vibration, friction and multiple backlashes is proposed. Firstly, based on the tooth contact analysis (TCA) of a double helical gear pair, the path of contact and meshing time from engagement to disengagement are obtained. The formula for determining the sliding friction coefficient is introduced. Based on TCA and the dynamic meshing force provided by the subsequent dynamics model of double helical gear pair, the sliding friction coefficient of the tooth surface is calculated. Secondly, the stiffness excitation, gear-into impact excitation and error excitation (including the axial displacement caused by the errors of manufacture and installation under low speed) are calculated according to the existing research results. Following this, a dynamic model of a double helical gear pair that takes into consideration the axial vibration, friction and multiple backlashes is both built and solved. Finally, an example is presented to verify the corresponding results.

Computation of Sliding Friction and Ratcheting Strain of Sintered and Hardened Steels Under Contact Fatigue Conditions

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
N. Govindarajan ◽  
R. Gnanamoorthy
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Sliding Friction ◽  
Fatigue Behavior ◽  
Contact Fatigue ◽  
Sliding Contact ◽  
Particle Analysis ◽  
Hardened Steels ◽  
Ratcheting Strain ◽  
Sliding Friction Coefficient

Fatigue properties of powder metallurgy parts are affected mainly by the porosity fraction. Even though it has inferior mechanical and physical properties over the conventional materials, the application of powder metallurgy products in automotive fields is seen in recent trends. The rolling-sliding contact fatigue behavior of sintered and hardened steels has been investigated by performing experiments that represent practical sliding friction coefficient component prevailing in the medium- and heavy-duty bearings and gears. Introduction of sliding friction coefficient changes the typical failure pattern and wear rate of sintered and hardened steels. The sliding friction has been computed from available models and compared with the experimental data. The ratcheting strain has also been predicted for sintered and hardened steels for various contact pressures and sliding friction coefficients. The maximum value of this strain is responsible for surface crack initiation. The wear particle analysis is carried out for the sintered and hardened steels under rolling-sliding contact fatigue conditions. The ferrogram slides for pore free steel under the rolling-sliding contact fatigue conditions are also prepared to study the effect of porosity in wear mechanism. The characteristics of wear morphology and the size, shape, and concentration of worn particles for sintered and hardened steels are also analyzed for various rolling-sliding contact fatigue conditions.

Coefficients of Friction

1949 ◽  
Vol 53 (468) ◽  
pp. 1085-1094 ◽  
Author(s):  
E. C. Pike
Keyword(s):  
Friction Coefficient ◽  
Surface Texture ◽  
Sliding Friction ◽  
Rolling Resistance ◽  
Aircraft Design ◽  
Resistance Coefficient ◽  
Surface Material ◽  
Primary Object ◽  
Different Types ◽  
Sliding Friction Coefficient

SummaryA summary is presented of information collected on coefficients of friction (rolling and sliding) between rubber tyres and road or runway surfaces. Nearly all the data collected are from tests on automobile tyres and are limited to speeds of about 40 m.p.h. In some cases the primary object of the tests was to distinguish between good and bad roads, and not to determine absolute values of friction coefficients.The reasons for the importance of the information for aircraft design use are discussed and distinctions are made between coefficients measured in different ways.The results show the variation of sliding friction coefficient with various parameters at speeds up to 40 m.p.h. There is a set of American tests at speeds up to 110 m.p.h., and some estimates made by the Dunlop Rubber Company up to 120 m.p.h.It is concluded that for sliding friction coeficients differences in surface texture (as distinct from surface material) are significant, and that information can be given only in the form of limits within which the values can be expected to lie.Few results are available on the variation of rolling resistance coefficient, but it is felt that the approximate values quoted for different types of surface are sufficiently accurate.

scholarly journals COMPUTATIONAL ESTIMATION OF SLIDING FRICTION COEFFICIENT EFFECT ON DURABILITY OF STRAIGHT-CUT SPUR GEARINGS

2019 ◽  
Vol 0 (1(82)) ◽  
Author(s):  
Мирон Васильович Чернець ◽  
Мирослав Васильович Кіндрачук ◽  
Олександр Вікторович Тісов ◽  
Анатолій Олександрович Корнієнко ◽  
Аліна Олександрівна Юрчук
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Computational Estimation ◽  
Sliding Friction Coefficient

scholarly journals Analytical assessment of the sliding friction coefficient influence on durability, wear and contact pressure in spur gears

2021 ◽  
Vol 49 (2) ◽  
pp. 472-479
Author(s):  
Myron Chernets ◽  
A. Kornienko ◽  
Yu. Chernets ◽  
S. Fedorchuk
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Tooth Wear ◽  
Gear Train ◽  
Point Of Entry ◽  
Gear Trains ◽  
Sliding Friction Coefficient ◽  
The One ◽  
Maximum Contact ◽  
Contact Pressures

The research of influence of sliding friction coefficient on durability is carried out for gear train containing steel wheels and metal-polymer gear trains containing polyamide gears reinforced with carbon and glass dispersion fibers. The teeth engagement conditions (two teeth pairs - single tooth pair - two teeth pairs) and the change of teeth tribocontact interaction conditions due to wear are also taken into account. The gear train containing the carbon-filled composite gear has the highest durability in comparison with other types in all ranges of change of sliding friction coefficient. The highest maximum contact pressures will be at the point of entry into the one-pair engagement. The change of initial maximum contact pressures in gear train due to tooth wear was also investigated and its regularities were established. The kinetics of the tooth profile wear was studied. It is established that the maximum wear will be at the point of entry into the one-pair engagement. Close to it will be the wear at the entrance into the two-pair engagement. The course of wear at different points of engagement for the studied gear trains containing steel toothed wheels and gear trains containing steel and composite gears is almost the same except for the point of the teeth exit from the engagement.

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