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1 – 3 of 3Ye Zhou, Degong Chang and Songmei Li
This paper aims to investigate the grease isothermal lubrication properties of the tripod sliding universal coupling (TSUC) in automotive transmission shaft and study its impact…
Abstract
Purpose
This paper aims to investigate the grease isothermal lubrication properties of the tripod sliding universal coupling (TSUC) in automotive transmission shaft and study its impact on a variety of factors to improve its grease lubrication properties.
Design/methodology/approach
Based on the simplified geometrical model, the research of grease lubrication properties of the TSUC was analyzed, and compared with oil lubrication in same parameters. Then the effects of effective radius, frequency (vehicle speed) and amplitude (angle between intermediate shaft and input shaft) on grease isothermal lubrication properties are theoretically investigated by using multigrid methods.
Findings
The results indicate that the grease isothermal elastohydrodynamic lubrication (EHL) film thickness shape and pressure distribution shape of the TSUC are similar to the oil lubrication, but the film thickness of grease lubrication is less than that of oil lubrication. Higher effective radius results in a wider pressure distribution, a lower center pressure and a thicker lubricating film. Higher frequency (vehicle speed) results in a remarkable second pressure peak and a thicker lubricating film. The effects of amplitude (angle between intermediate shaft and input shaft) and frequency have similar tendencies.
Originality/value
The numerical analysis research on grease lubrication properties of the TSUC is significant because the automotive transmission shaft is widely used. And it provides a new direction in designing TSUCs.
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Ye Zhou, Degong Chang and Songmei Li
This paper aims to improve the grease thermal elastohydrodynamic lubrication (TEHL) properties of the tripod sliding universal coupling (TSUC) under automotive practical…
Abstract
Purpose
This paper aims to improve the grease thermal elastohydrodynamic lubrication (TEHL) properties of the tripod sliding universal coupling (TSUC) under automotive practical conditions. For this purpose, the effect of effective radius was theoretically investigated.
Design/methodology/approach
Based on the simplified geometric model, the effect of effective radius on the pressure distribution, film thickness and temperature distribution of the TSUC was theoretically investigated using the multigrid and stepping methods. The TEHL properties were compared with the results obtained using the isothermal calculation method.
Findings
The results show that the thermal effect has a great impact on the film thickness and the pressure distribution of grease lubrication properties. Moreover, larger effective radius results in a wider but lower pressure distribution, a wider and thicker lubricating film and a lower temperature distribution.
Originality/value
The TSUC can be widely used in the front drive automotive transmission because it can transmit larger torque than before. The effect of effective radius on the thermal grease lubrication properties under automotive practical conditions provides a new direction for designing it.
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Hamed Tirandaz and Ali Karami-Mollaee
The purpose of this paper is to propose a novel and secure image transmission based on the unpredictable behavior of the chaotic systems.
Abstract
Purpose
The purpose of this paper is to propose a novel and secure image transmission based on the unpredictable behavior of the chaotic systems.
Design/methodology/approach
The proposed approach includes two main contributions: synchronization scheme and transmission scheme. The synchronization scheme benefits the advantage of the fractional-order active synchronization method. A new control law is derived to asymptotically synchronize the underlined fractional-order Bloch chaotic system. The validity of the proposed synchronization scheme is proved by the Lyapunov stability theorem. Then, a novel image transmission scheme is designed to transfer image data via chaotic signals, which modulates the encrypted data in the sender signals and demodulates it at the receiver side.
Findings
Numerical simulations are provided to show the validity and effectiveness of the proposed image transmission system. Furthermore, the performance of the image transmission system is evaluated using some illustrative examples and their corresponding statistical tests. The results demonstrate the effectiveness of the proposed method in comparison with other proposed methods in this subject.
Originality/value
A new chaos-based image transmission system is developed based on the synchronization of Bloch chaotic system. The introduced transmission system is interesting and could be applicable to any kind of secure image/video transmission.
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