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Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Biomass Chemical Engineering is the property of Editorial Office of Biomass Chemical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of Beijing Institute of Technology is the property of Beijing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A theoretical model is established for the analysis of offset state of friction elements under the condition of low speed difference based on the gyro effect. As for the gap shrinkage under the condition of high speed difference, a negative pressure contraction model for friction pairs is built by analyzing the oil film and the pressure on friction plates. The dynamic change of gap between the friction pairs in the whole variation range of the relative speed is then investigated. Finally, an improved model, considering the influence of dynamic change of gap between the friction pairs, is proposed to study the drag torque. The simulated and test results indicate that, under the condition of the same lubrication, the drag torque of the wet multi-plate clutch increases first and then decreases and finally increases with the rise of the rotational speed difference. The main factors influencing the drag torque are the offset of friction plate under the condition of the low speed difference (0-1 000 r/min), and the gap shrinkages under the condition of the middle and high speed differences (>1 000 r/min). Through the comparison of test results and the simulated results obtained from the improved model, the average relative error is only 6.34% under the condition of medium and high speed differences (>1 000 r/min), which can greatly improve the estimation accuracy of drag torque of wet multi-plate clutch. [ABSTRACT FROM AUTHOR]

In order to investigate the influence of circlip constraint on the contact stress distributions of multi-disc clutch, a 3 D finite element model is developed by Abaqus software. The contact stress distribution is obtained by the 3 D finite element model, and the temperature distribution is obtained through numerical simulation. The simulated and experimental results show that the concentrated load of circlip results in the uneven distribution of radial contact stress of friction pairs during the clutch engagement process. The closer the friction surface is to the circlip, the larger the contact stress of outer radius of friction surface is, and the more obvious the difference of the radial contact stress is; when the friction pair is away from the circlip, the contact stress gets closer and closer to the piston pressure, and the difference of radial contact stress tends to be ease. The concentrated load of circlip leads to the increase in the radial temperature difference. The temperature in outer radius rises significantly, while the temperature in inner radius increases slowly. Moreover, the temperature fields of friction components in different axial directions are inconsistent, and the friction component near the circlip is more prone to be buckled. The proposed temperature field model is verified effectively by long time, low speed sliding experiments, which can better reflect the actual temperature rise characteristics of the multi-disc clutch. [ABSTRACT FROM AUTHOR]

This work focuses on the influence of rotating speed on local lubrication and friction charac- teristics of wet clutch. A thermal mixed lubrication model in plane contacts is developed, and the pin-on-disc tests are conducted on universal material tester (UMT). Local pressure distribution, load sharing ratio, contact area ratio, local temperature rise and friction coefficient are analyzed. The results show that, as the rotating speed rises, hydrodynamic pressure grows significantly, while real contact area of friction pair reduces obviously. The main normal load is supported by hydrodynamic film. The friction coefficient is mainly affected by the change of asperity contact area, and has rough congruent relationship with the real contact area ratio. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of Beijing Institute of Technology is the property of Beijing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

On the basis of the lumped parameter method which simplifies the components in hydraulic system to nodes, a thermal resistance network model of clutch hydraulic system is proposed to investigate the effects of oil flow and rotation speed difference on the temperature rise of wet clutch during engaging. An experimental device is designed to validate the simulation results. The results show that the oil flow rate has a greater influence on the temperature rise of wet clutch under the condition of high heat flux than that under the condition of low heat flux. The oil flow brings a slight effect on the temperature rise when the cooling flow increases to the critical value. Both the relative speed and the pressure have an influence on heat flux. The temperature of wet clutch is a linear function of the relative speed of friction plates. The clutch temperature rises by 8.05 percent with every 100 r/min increment in the relative speed under same cooling condition. The proposed model is verified effectively by comparison of simulated results and experimental data, which can better reflect the thermal equilibrium of wet clutch hydraulic system in normal condition. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)