Experimental study on the friction stability of paper-based clutches concerning groove patterns

2019 ◽  
Vol 72 (4) ◽  
pp. 541-548 ◽  
Author(s):  
Liang Yu ◽  
Biao Ma ◽  
Man Chen ◽  
He Yan Li ◽  
Jikai Liu
Keyword(s):  
Experimental Study ◽  
Surface Temperature ◽  
Design Methodology ◽  
Automatic Transmission ◽  
Applied Pressure ◽  
Friction Torque ◽  
Content Type ◽  
Rotating Speed ◽  
Wet Clutch ◽  
Transmission Fluid

Purpose This paper aims to study and compare the friction stability of wet paper-based clutches with regard to the radial grooves (RG) and waffle grooves (WG). Design/methodology/approach This paper presents an experimental study of a wet clutch concerning the effect of groove patterns on the friction torque and surface temperature. The friction stabilities of RG and WG are investigated with the applied pressure, rotating speed and automatic transmission fluid (ATF) temperature taken into consideration. Findings The friction torque and surface temperature of WG are larger than those of RG under the same operating condition. The friction torque difference between RG and WG grows with the increase of applied pressure and narrows with the increase of ATF temperature. Additionally, their temperature difference expands via increasing the rotating speed and ATF temperature or reducing the applied pressure; in this way, not only the variable coefficient difference between RG and WG can be narrowed, but also the friction stability of the clutch can be improved dramatically. Originality/value This paper explains the thermodynamic differences between RG and WG; moreover, it is verified experimentally that WG has a better friction stability than RG.

scholarly journals Effect of Silicon Carbide Nanoparticles on the Friction-Wear Properties of Copper-Based Friction Discs

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 587
Author(s):  
Changsong Zheng ◽  
Zhiwei Ma ◽  
Liang Yu ◽  
Xu Wang ◽  
Liangjie Zheng ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Variable Coefficient ◽  
Automatic Transmission ◽  
Applied Pressure ◽  
Friction Torque ◽  
Bench Test ◽  
Friction Materials ◽  
Wear Characteristics ◽  
Rotating Speed ◽  
Silicon Carbide Nanoparticles

To study the influence of nano-additives on the friction-wear characteristics of friction materials, the nano-sized silicon carbide particles which have excellent chemical and physical properties are considered to add in composite to form the modified friction material. The influence of the silicon carbide nanoparticles (SCN) on the friction-wear characteristics of copper-based friction materials (CBFM) is investigated via the SAE#2 (made in Hangzhou, China) clutch bench test with the applied pressure, rotating speed, and automatic transmission fluid (ATF) temperature taken into account. Moreover, the variations of friction torque and temperature are considered to evaluate the friction performance, and the variable coefficient is employed to describe the friction stability. The wear characteristics of friction materials are investigated by the disc changes in thickness and micro-morphology. The results show that the CBFM with SCN can provide a higher friction torque, which increased by 30% to 50% compared with CBFM. The variable coefficient of CBFM with SCN changes from 674 to 52 with the rotating speed raised from 600 rpm to 3000 rpm, which shows that the friction stability is relatively worse. Furthermore, the micromorphology shows that the CBFM with SCN has lower porosity and surface roughness, which increases the microscopic contact area and the coefficient of friction (COF). Simultaneously, the reduction in porosity also leads to a decrease in the cooling quality, bringing about a rapid temperature rise. Thus, the wear amount of CBFM with SCN increases significantly, especially for the friction disc in the axial middle position.

scholarly journals Evaluation of thermo-oxidized Jatropha bio-oil in lubrication of actual wet clutch materials

2020 ◽  
pp. 135065012098146
Author(s):  
Leonardo I Farfan-Cabrera ◽  
Ezequiel A Gallardo-Hernández ◽  
José Pérez-González ◽  
Benjamín M Marín-Santibáñez ◽  
Roger Lewis ◽  
...  
Keyword(s):  
Automatic Transmission ◽  
Viscosity Index ◽  
Jatropha Oil ◽  
Oxidative Aging ◽  
Lubrication Regime ◽  
Viscosity Increase ◽  
Bio Oil ◽  
Wet Clutch ◽  
Transmission Fluid ◽  
Pin On Disk

In this work, an assessment of the performance of thermo-oxidated Jatropha oil as a lubricant for actual wet clutch materials was performed and compared with a commercial automatic transmission fluid. For this, Jatropha oil, a commercial automatic transmission fluid and a blend of 20 vol% Jatropha oil–80 vol% automatic transmission fluid were subjected to thermo-oxidative aging at 26 °C and 100 °C, followed by a pin-on-disk testing with disk samples from an actual wet clutch. Evaluation of the film thickness at the sliding interface resulted in a boundary lubrication regime for all the tests. The changes in oxidation, viscosity, and a viscosity index of the samples were evaluated along with friction coefficients at various sliding speeds. Jatropha oil was the most sensitive to thermo-oxidation. Jatropha oil and the blend showed a higher viscosity increase than automatic transmission fluid with thermo-oxidation, while the viscosity index of all oils was decreased considerably, Jatropha oil and the blend being the most reduced. Finally, the anti-shudder property, as measured by the change in the friction coefficient with a sliding speed, of Jatropha oil and automatic transmission fluid was improved by thermo-oxidation at 26 °C but worsened at 100 °C, meanwhile it was barely affected in the blend. Therefore, these results indicate that using pure Jatropha oil as automatic transmission fluid would be unsuitable, but blending it with automatic transmission fluids in specific proportions may be apposite for improving the friction properties of wet clutches even under thermo-oxidative conditions.

Experimental study of pin surface precision on lubrication behavior of pin–bush pairs in industrial roller chains

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ansheng Zhang ◽  
Mingyu Zhang ◽  
Jing Wang ◽  
Jianjun Zhang ◽  
Zhaohua Shang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Design Methodology ◽  
Industrial Applications ◽  
Experimental Basis ◽  
Reciprocating Motion ◽  
Content Type ◽  
Oil Supply ◽  
Machining Errors ◽  
Surface Precision ◽  
Straightness Error

Purpose The purpose of this paper is to study the influence of surface precision on the lubrication state of the roller chain under adequate and rare oil supply conditions, respectively. Design/methodology/approach The straightness error and roughness error of the pin generatrices were measured and the influence of surface precision on the lubrication behavior under steady state and reciprocating motion was studied through optical interference experiments. Findings The lubrication state is strongly influenced by the surface precision of the roller surface both under adequate oil supply and rare oil supply conditions. Originality/value In industrial applications, the machining errors of parts cannot be completely eliminated. Studying the influence of the surface precision on the lubrication behavior of pin–bush pairs can provide the experimental basis for the optimal design of the bush roller chains.

Does coffee taste better with latte art? A neuroscientific perspective

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Liwei Hsu ◽  
Yen-Jung Chen
Keyword(s):  
Experimental Study ◽  
Bayesian Statistics ◽  
Empirical Evidence ◽  
Design Methodology ◽  
Visual Stimulation ◽  
Coffee Consumption ◽  
Two Stage ◽  
Content Type ◽  
Business Environments ◽  
Original Contribution

PurposeVisual stimulation affects the taste of food and beverages. This study aimed to understand how latte art affects coffee consumption by collecting participants' brainwave data and their taste responses.Design/methodology/approachSeventy subjects participated in a two-stage experiment. Electroencephalography (EEG) was employed to measure brainwave activity. With an interval of one week, each stage involved coffee consumption with and without latte art. The responses to the taste of the coffee were also collected for analysis.FindingsSignificant differences were found in the participants' alpha and beta brainwave bands. When drinking coffee with latte art, the participants' alpha bands were significantly lower, whereas the beta bands were higher. These findings were supported by Bayesian statistics. A significant increase was found in the participants' taste of sweetness and acidity with latte art, and Bayesian statistics confirmed the results for sweetness although the evidence on the increase in acidity was anecdotal. No difference was found in the taste of bitterness.Originality/valueThis study highlights the effect of latte art on coffee consumption. The authors analysed the empirical evidence from this two-stage experimental study in the form of the participants' brainwave data and their responses to taste. This study's original contribution is that it explored the crossmodal effects of latte art on consumers' taste of coffee from a neuroscientific perspective. The results of this study can provide empirical evidence on how to effectively use latte art in practical business environments.

Managers’ reactions to customer vs coworker sexual harassment

2018 ◽  
Vol 30 (2) ◽  
pp. 1211-1227 ◽  
Author(s):  
Juan M. Madera ◽  
Priyanko Guchait ◽  
Mary Dawson
Keyword(s):  
Experimental Study ◽  
Sexual Harassment ◽  
Organizational Climate ◽  
Design Methodology ◽  
Well Being ◽  
Content Type ◽  
Educational Implications ◽  
Hotel Managers ◽  
Hospitality Managers ◽  
Practical Implications

Purpose The purpose of this paper is to examine how managers react to sexual harassment as a function of the harasser role that includes a customer as a source of harassment and an organization’s climate for sexual harassment. Design/methodology/approach Using an experiment with a 2 (harasser role: coworker or customer) × 2 (organizational climate of sexual harassment: tolerates or does not tolerate) between-subjects design, 162 hotel managers were randomly assigned to read one of four conditions. Findings Both the harasser role and organization’s climate for sexual harassment influenced the managers’ sexual harassment reactions, specifically whether they label the incident as sexual harassment and attribute responsibility to the organization. The managers’ gender was found to moderate these relationships. Practical implications The results underscore the importance of understanding reactions to sexual harassment because, regardless of who harasses (coworker or customer) and the organizational climate (tolerates or does not tolerate sexual harassment), sexual harassment of any form can be harmful for the well-being of hospitality employees. These results also provide educational implications. Originality/value This is the first known experimental study to examine how hospitality managers react to sexual harassment when the harasser role includes a customer versus a coworker. The results illustrate that the same sexually harassing behavior was perceived less negatively – in regard to both the labeling and attribution of organizational responsibility – when it was done by a customer than by a coworker.

Brand balance: the effect of influencer brand encroachment on interactivity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lara Hamdan ◽  
Seung Hwan (Mark) Lee
Keyword(s):  
Social Media ◽  
Experimental Study ◽  
Design Methodology ◽  
Mediating Effects ◽  
Personal Power ◽  
Content Type ◽  
Low Level ◽  
Social Media Platforms ◽  
High Level

PurposeAs social media platforms continue to have an increased presence in influencer marketing, researchers and practitioners are seeking ways to optimize the use of these platforms. The purpose of this study is to investigate the effect of brand encroachment, a level of brand's control over the promotion executed by social media influencers (SMIs), on the importance of interactivity of SMIs.Design/methodology/approachThis study examined the effect of brand encroachment on interactivity whilst examining the mediating effects of both passion and personal power. The study was an online, one-factor between-subjects design comparing high level of brand encroachment vs low level of brand encroachment.FindingsThe results of the experimental study suggest that as brand encroachment decreases, there is an increasing importance of being interactive. In addition, with lower brand encroachment, SMIs portray more personal power and passion toward the product or service being promoted.Originality/valueAs influencers create communities via increased levels of engagement, authenticity and relatability, it is of paramount importance that SMIs build relationships through interactivity in low-brand encroachment settings. Brands should offer more opportunities for SMIs to be interactive with their audience, while intrinsically building their personal power and passion as sources for these interactions.

Revisiting the service recovery paradox in the restaurant industry

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jong-Hyeong Kim ◽  
Wenxuan Du ◽  
Hyewon Youn
Keyword(s):  
Experimental Study ◽  
Field Study ◽  
Design Methodology ◽  
Service Management ◽  
Service Recovery ◽  
Restaurant Industry ◽  
Content Type ◽  
Service Failures ◽  
Service Recovery Paradox ◽  
Practical Implications

PurposeThe service recovery paradox (SRP) refers to a particular effect whereby an excellent recovery can turn angry and frustrated customers into loyal ones. Researchers who have studied the SRP have reported mixed findings, with some providing evidence in its support and others not finding any such evidence. To address this discrepancy, this study aims to investigate the SRP.Design/methodology/approachThis study re-examined the phenomenon of the SRP with a field study and provided further evidence in a subsequent experimental study in which the failure and recovery conditions were carefully manipulated.FindingsThe results of this study suggest that the SRP was observed in neither the field study nor the scenario experiment.Practical implicationsThis study can influence the current service management of restaurants with regard to service failures in several ways.Originality/valueThis research is a pioneering effort to examine the SRP by conducting both a field study and a scenario experiment.

Influence of steel fibres on friction behaviours with respect to speed, pressure and temperature

2017 ◽  
Vol 69 (3) ◽  
pp. 420-424 ◽  
Author(s):  
Talib Ria Jaafar ◽  
Noor Iswadi Ismail ◽  
Mohd Fauzi Ismail ◽  
Eliasidi Abu Othman
Keyword(s):  
Surface Temperature ◽  
Steel Fibre ◽  
Applied Pressure ◽  
The Other ◽  
Brake Pad ◽  
Volume Percentage ◽  
Content Type ◽  
Pressure Surface ◽  
Two Samples ◽  
Braking Process

Purpose This study aims to investigate the effect of different volume percentage (Vol.%) of steel fibre on the pressure, surface temperature and speed sensitivity behaviour during braking process as known brake effectiveness and to propose the best steel fibre Vol.% in the formulation. Design/methodology/approach Three brake pads composed of three different steel fibre volume percentages were fabricated through powder metallurgy route. Selecting one sample as based formulations, steel fibre (Vol.%) was decreased and increased by 50 per cent in the other two samples, respectively. The other ingredients are proportionally increased and decreased accordingly to the base formulation. The samples were tested for determining their hardness, porosity and coefficient of friction (COF) using Rockwell hardness tester, hot bath and brake inertia dynamometer, respectively. Findings Test results indicated that Sample T1 which composed of 9 Vol.% of steel fibre had the lowest COF and was sensitive to applied pressure, surface temperature and speed. The samples which composed of 18 and 27 Vol.% of steel fibre were having the same trend of COF and were sensitive to surface temperature and speed. Sample T which composed of 18 Vol.% of steel fibre had lower brake pad and disc lost as compared to Sample T2 which composed of 27 Vol.%. Mechanical properties did not show any significant correlation with COF sensitivity with temperature, speed and pressure. Originality/value The sample with 18 Vol.% of steel fibre was found to be the best formulation which produced acceptable COF; less sensitive to temperature, pressure and speed during braking process; and better wear resistance of brake pad as well as the rotor.

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