Estimation of Bearing Capacity and Wear Resistance of Spur Gear Meshing Taking into Account Tooth Profile Correction and Sliding Friction Coefficient

Author(s):  
Myron V. Chernets ◽  
Serge V. Shil’ko ◽  
Victor E. Starzhinsky
Author(s):  
Andris Martinovs ◽  
Vladimir Gonca

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.


2019 ◽  
Vol 24 (3) ◽  
pp. 476-484 ◽  
Author(s):  
Cheng Wang ◽  
Shouren Wang ◽  
Gaoqi Wang

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.


2008 ◽  
Vol 130 (4) ◽  
Author(s):  
N. Govindarajan ◽  
R. Gnanamoorthy

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.


1949 ◽  
Vol 53 (468) ◽  
pp. 1085-1094 ◽  
Author(s):  
E. C. Pike

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.


2012 ◽  
Vol 538-541 ◽  
pp. 336-339 ◽  
Author(s):  
Dong Sheng Wang ◽  
Zong Jun Tian ◽  
Song Lin Wang ◽  
Li Da Shen

It has attracted very strong interests in enhancing the wear resistance of the TiAl intermetallic alloy. In this paper, both plasma-sprayed conventional and nanostructured ZrO2-7wt.%Y2O3 thermal barrier coatings (TBCs) were prepared on TiAl alloy, and microhardness of coating were investigated. Meanwhile, the dry sliding friction tests on the substrate, the traditional coating, and the nanostructured coating were evaluated by ball-on-disk tribometer at room temperature. The results show that the microhardness of nanostructured coating is higher than that of the conventional one. Lower friction coefficient and higher wear resistance than the original TiAl alloy is achieved in the coatings under wear test conditions. Due to the existence of nanostructured microstructures, the nanostructured coating exhibits the lowest friction coefficient, and the best wear resistance. The wear mechanism of the original TiAl substrate is severe adhesive wear. However, the wear mechanisms of the TBCs are mild ploughing and severe adhesion.


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

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