Study of the frictional properties of brake pads with different relief of oil ducts

2015 ◽  
Vol 5 (1) ◽  
pp. 215-222
Author(s):  
Поляков ◽  
Nikolay Polyakov
Keyword(s):  
Friction Surface ◽  
Friction Material ◽  
Supply System ◽  
Brake Pads ◽  
Frictional Properties ◽  
Braking Torque ◽  
Order Of Magnitude ◽  
Scale Experiment ◽  
Selection Of ◽  
Tractor Plant

Some technological operations – stump extraction, preparation of forest roads are made by machines based on powerful caterpillar tractors. One of the problematic units of caterpillar tractors is band brakes of "dry" friction. Typically, friction tape must be changed after two ТО-3. Belt shoe brakes, working in oil, have higher durability (at least one order of magnitude). Apart from the choice of a special friction material for such a brake oil supply system must be ensured and special oil ducts on the working surfaces of the pads. In the literature several fundamental configurations of ducts are known. We, together with specialists from Cheboksary Industrial Tractor Plant have selected cruciform shape of cutting ducts. Due to a variety of factors and difficulties passing on the cutting-friction contact of phenomena analytical method for the selection of the geometry of ducts is difficult. We used full-scale experiment with the previously selected friction asbestos polymer material no. 410-120. Tests were conducted on a combined stand. To simplify this type of test we used not the whole belt of the four pads, but only one pad. To do this, stand design was modified; strain-gage chain was changed to record braking torque. The tests were carried out under braking stops. Different geometries of oil ducts on the different modes of operation were explored. The following parameters were varied: the density of cutting; the width of the ducts; depth of the ducts; angle to the axis of the ducts. Frictional properties and the temperature at the friction surface were evaluated. The best performances of ducts cutting were chosen after tests. mm; mm; mm ; . The results of the work are introduced in production.

THE INFLUENCE OF THE SURFACE LAYER STRUCTURE IN DISC BRAKE PADS ON THEIR TRIBOLOGICAL PROPERTIES

Tribologia ◽  
2016 ◽  
Vol 267 (3) ◽  
pp. 71-85
Author(s):  
Andrzej GAJEK ◽  
Wojciech SZCZYPIŃSKI-SALA
Keyword(s):  
Friction Surface ◽  
Chemical Elements ◽  
Layer Structure ◽  
Friction Material ◽  
Compact Structure ◽  
Friction Layer ◽  
Brake Pads ◽  
Disc Brakes ◽  
The Coefficient Of Friction ◽  
Point Line

The article presents the results of the stand tribological investigation and microscopic observations of brake pad materials for automotive disc brakes. The reasons for the scatter of the friction coefficient value are analysed. The results of the brake pads’ friction surface topography observations and chemical constitution are presented. The investigations were carried out with scanning electron microscopy SEM and energy dispersive X-ray spectroscopy EDS. The point, line, and surface analysis of friction layer were done. The average contents of the chemical elements on the friction surface are presented. The heterogeneous nature of the structure on the friction layer was observed. The analysis has shown that brake pads with a compact structure of friction layer and large quantity components (10 components with more than 1% content each) had a smaller scatter of the coefficient of friction value in relation to the materials with a loose structure and less quantity components. The next part of the article presents the structure and geometric parameter products of the wear of the friction material. The problem concerning the quantity limitation of the wear particles entering the environment as dust was discussed.

Development of the algorithm for the selection of a wind generator-based autonomous power supply system

2019 ◽  
Vol 2 (1) ◽  
pp. 8-16 ◽  
Author(s):  
P. A. Khlyupin ◽  
G. N. Ispulaeva
Keyword(s):  
Wind Turbines ◽  
Power Supply ◽  
Alternative Energy ◽  
Power Supply System ◽  
Supply System ◽  
Power Generators ◽  
Energy Devices ◽  
Wind Generator ◽  
Alternative Energy Sources ◽  
Selection Of

Introduction: The co-authors provide an overview of the main types of wind turbines and power generators installed into wind energy devices, as well as advanced technological solutions. The co-authors have identified the principal strengths and weaknesses of existing wind power generators, if applied as alternative energy sources. The co-authors have proven the need to develop an algorithm for the selection of a wind generator-based autonomous power supply system in the course of designing windmill farms in Russia. Methods: The co-authors have analyzed several types of wind turbines and power generators. Results and discussions: The algorithm for the selection of a wind generator-based autonomous power supply system is presented as a first approximation. Conclusion: The emerging algorithm enables designers to develop an effective wind generator-based autonomous power supply system.

scholarly journals The research of dynamic impacts on the hydraulic structure foundation base, transformed in the process of accident recovery

2018 ◽  
Vol 251 ◽  
pp. 04040
Author(s):  
Zaven Ter-Martirosyan ◽  
Ivan Luzin
Keyword(s):  
Field Experiments ◽  
Dynamic Properties ◽  
Soil Parameters ◽  
Experimental Site ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Foundation Base ◽  
Dynamic Impacts ◽  
Scale Experiment ◽  
Selection Of

The article presents the results of a comprehensive research of the dynamic impacts on a modified base. The modified base was obtained as a result of compensatory injection at the experimental site for the accident recovery at the hydraulic engineering structure. The complex study of the dynamic impacts includes special laboratory tests to determine the soil parameters, the finite element analysis of the experimental site, taking into account the dynamic properties, the selection of the necessary equipment for field experiments based on the numerical solution results, a full-scale experiment with the measurement of the foundation sediments of the experimental site.

scholarly journals Impact of Operating Time on Selected Tribological Properties of the Friction Material in the Brake Pads of Passenger Cars

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 884
Author(s):  
Andrzej Borawski
Keyword(s):  
Tribological Properties ◽  
Operating Time ◽  
Friction Material ◽  
Operating Conditions ◽  
Direct Impact ◽  
Passenger Cars ◽  
Wear Factor ◽  
Brake Pads ◽  
Road Users ◽  
The Coefficient Of Friction

Braking systems have a direct impact on the safety of road users. That is why it is crucial that the performance of brakes be dependable and faultless. Unfortunately, the operating conditions of brakes during their operating time are affected by many variables, which results in changes in their tribological properties. This article presents an attempt to develop a methodology for studying how the operating time affects the value of the coefficient of friction and the abrasive wear factor. The Taguchi method of process optimization was used to plan the experiment, which was based on tests using the ball-cratering method. The results clearly show that the degree of wear affects the properties of the friction material used in the production process of brakes.

Braking performance of a novel frictional-magnetic compound disc brake for automobiles

2018 ◽  
Vol 233 (10) ◽  
pp. 2443-2454 ◽  
Author(s):  
Yan Yin ◽  
Jiusheng Bao ◽  
Jinge Liu ◽  
Chaoxun Guo ◽  
Tonggang Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temperature Rise ◽  
Friction Material ◽  
Maximum Temperature ◽  
Interface Temperature ◽  
Disc Brake ◽  
Braking Performance ◽  
Maximum Temperature Rise ◽  
Disc Brakes ◽  
Braking Torque

Disc brakes have been applied in various automobiles widely and their braking performance has vitally important effects on the safe operation of automobiles. Although numerous researches have been conducted to find out the influential law and mechanism of working condition parameters like braking pressure, initial braking speed, and interface temperature on braking performance of disc brakes, the influence of magnetic field is seldom taken into consideration. In this paper, based on the novel automotive frictional-magnetic compound disc brake, the influential law of magnetic field on braking performance was investigated deeply. First, braking simulation tests of disc brakes were carried out, and then dynamic variation laws and mechanisms of braking torque and interface temperature were discussed. Furthermore, some parameters including average braking torque, trend coefficient and fluctuation coefficient of braking torque, average temperature, maximum temperature rise, and the time corresponding to the maximum temperature rise were extracted to characterize the braking performance of disc brakes. Finally, the influential law and mechanism of excitation voltage on braking performance were analyzed through braking simulation tests and surface topography analysis of friction material. It is concluded that the performance of frictional-magnetic compound disc brake is prior to common brake. Magnetic field is greatly beneficial for improving the braking performance of frictional-magnetic compound disc brake.

scholarly journals Likert scale and change in range of response categories vs. the factors extraction in EFA model

2015 ◽  
Vol 1 (311) ◽  
Author(s):  
Piotr Tarka
Keyword(s):  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Rating Scale ◽  
Likert Scale ◽  
Optimal Number ◽  
Number Of Factors ◽  
Scale Experiment ◽  
Methodological Aspects ◽  
The Impact ◽  
Selection Of

Abstract: The objective article is the comparative analysis of Likert rating scale based on the following range of response categories, i.e. 5, 7, 9 and 11 in context of the appropriate process of factors extraction in exploratory factor analysis (EFA). The problem which is being addressed in article relates primarily to the methodological aspects, both in selection of the optimal number of response categories of the measured items (constituting the Likert scale) and identification of possible changes, differences or similarities associated (as a result of the impact of four types of scales) with extraction and determination the appropriate number of factors in EFA model.Keywords: Exploratory factor analysis, Likert scale, experiment research, marketing

Design of a frictional–electromagnetic compound disk brake for automotives

2019 ◽  
Vol 234 (4) ◽  
pp. 1113-1122
Author(s):  
Shan Huang ◽  
Jiusheng Bao ◽  
Shirong Ge ◽  
Yan Yin ◽  
Tonggang Liu
Keyword(s):  
High Speed ◽  
Test Bench ◽  
Theory Model ◽  
Comsol Multiphysics ◽  
Simulation Test ◽  
Braking Performance ◽  
Brake Pads ◽  
Disk Brake ◽  
Braking Torque ◽  
The Magnetic Field

According to the disadvantages of serious wear and heat fade of friction pad in frequent and high speed braking of friction brakes, and the insufficient power of electromagnetic brakes in low speed braking, a novel frictional-electromagnetic compound disk brake which combines both of these two brake principles is proposed for automotives in this paper. The excitation coils are designed based on the Zhang Yicheng theory model, and the compound brake prototype is manufactured based on the self-made magnetic brake pads and existing automotive brakes. The magnetic field and dynamic of the brake are simulated by using COMSOL Multiphysics software. The frictional–electromagnetic compound brake tests are implemented on the reconstructive disk brake simulation test bench. The experimental results show that the friction braking torque accounts for more than 90% of the compound braking torque in the process of compound braking, and the trend of the change is the same as that of the compound braking torque. When the initial braking speed exceeds 75 km/h, the electromagnetic braking torque does not increase with the increase in speed, instead, it decreases slightly because of demagnetization. The designed frictional–electromagnetic compound disk brake has good braking performance.

A retrofit for asbestos-based brake pad employing palm kernel fiber as the base filler material

2018 ◽  
Vol 233 (9) ◽  
pp. 1906-1913 ◽  
Author(s):  
CH Achebe ◽  
JL Chukwuneke ◽  
FA Anene ◽  
CM Ewulonu
Keyword(s):  
Specific Gravity ◽  
Palm Kernel ◽  
Friction Material ◽  
Mechanical Tests ◽  
Filler Material ◽  
Oil Absorption ◽  
Brake Pad ◽  
Brake Pads ◽  
The Matrix ◽  
Automotive Brake

The development of automobile brake pad using locally sourced palm kernel fiber was carried out. Asbestos, a carcinogenic material, has been used for decades as a friction material. This development has thus prompted a couple of research efforts geared towards its replacement for brake pad manufacture. Palm kernel fiber was used as an alternative filler material in conjunction with various quantities of epoxy resin as the matrix. Three sets of compositions were made, and the resulting specimens subjected to physical and mechanical tests using standard materials, procedures, and equipment. The essence is to determine their suitability and hence possible performance in service. The result showed that sample C with 40% palm kernel fiber content having hardness, compressive strength, abrasion resistance, specific gravity, water absorption, and oil absorption of 178 MPa, 96.2 MPa, 1.67 mg/m, 1.8 g/cm3, 1.86%, and 0.89%, respectively, had an optimum performance rating. It was equally ascertained that increase in the filler content had the effect of increase in hardness, wear resistance, and specific gravity of the composite brake pad, while water and oil absorption got decreased when compared with results obtained by other researchers using conventional brake pads made of other friction materials including asbestos. This is an indicator that palm kernel fiber is a possible and effective retrofit for asbestos as a filler material in automotive brake pad manufacture.

How effective is KRM-1648 in treatment of disseminated Mycobacterium avium complex infections in beige mice?

1996 ◽  
Vol 40 (2) ◽  
pp. 437-442 ◽  
Author(s):  
B Ji ◽  
N Lounis ◽  
C Truffot-Pernot ◽  
J Grosset
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Antimicrobial Effect ◽  
Bacteriostatic Effect ◽  
Dose Selection ◽  
Order Of Magnitude ◽  
The Mean ◽  
Resistant Mutants ◽  
Selection Of

Although the MICs of 3'-hydroxy-5'-(4-isobutyl-1-piperazinyl)benzoxazinorifamycin, or KRM-1648 (KRM), for Mycobacterium avium complex (MAC) were significantly lower than those of other drugs, its in vivo activity was very weak. Beginning 28 days after inoculation, beige mice that had been infected intravenously with 1.87 x 10(7) CFU of MAC 101 were administered KRM alone, clarithromycin (CLARI) alone, or CLARI plus KRM six times weekly for 16 weeks. In contrast to the mice treated with CLARI-containing regimens, the mortality and the mean spleen weights of mice treated with KRM alone (either 10 or 20 mg/kg of body weight per dose) did not differ significantly from those of untreated mice, their numbers of CFU were very much greater than pretreatment values, and multiplication of MAC was only slightly inhibited. Although monotherapy by KRM selected KRM-resistant mutants, the selection was very weak; the mean number of CFU and the frequency of KRM-resistant mutants increased by no more than 1 order of magnitude after 16 weeks of treatment with KRM at 20 mg/kg per dose. Selection of CLARI-resistant mutants was inhibited but not completely prevented by treatment of the mice with CLARI plus KRM. These results indicate that KRM displayed only a weak bacteriostatic effect against the isolate tested in the beige mouse model; its ability to enhance the antimicrobial effect of CLARI or to prevent emergence of CLARI-resistant mutants was very limited.

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