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15 pages, 15125 KiB

Open AccessArticle

Experimental Validation of a Permanent Magnets Magnetorheological Device under a Standardized Worldwide Harmonized Light-Duty Test Cycle

by Claudia Simonelli, Luca Sani, Nicolò Gori, Miguel Fernández-Muñoz, Antonino Musolino and Rocco Rizzo

Actuators 2023, 12(10), 375; https://doi.org/10.3390/act12100375 - 29 Sep 2023

Cited by 2 | Viewed by 2030

Abstract

In this paper, the experimental validation of an innovative clutch based on magnetorheological fluids (MRFs) excited by permanent magnets is described. The device, used in automotive applications to engage and disengage the vacuum pump, is tested using a standardized Worldwide harmonized Light-duty Test Cycle (WLTC). A test bench is built, and the system is observed in its operation for one hour, considering two consecutive WLTCs. The temperature increase slightly impacts the clutch’s behavior; in particular, the on-state performance of the device, mainly determined by the magnetic field-induced torque, remains largely unaffected by the temperature increase. The results showed that the performance of the proposed MRF-based device is only marginally affected by the phenomena that take place during the actual operation (e.g., temperature increase, shaft slip), confirming the effectiveness of the design. Full article

(This article belongs to the Special Issue Electromagnetic Actuators)

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9 pages, 2436 KiB

Open AccessArticle

First Description of the Breeding Biology of the Spectacled Fulvetta (Fulvetta ruficapilla sordidior) in Southwest China

by Shixiang Fan, Jiansong Zhang, Yubao Duan and Xu Luo

Animals 2023, 13(13), 2157; https://doi.org/10.3390/ani13132157 - 30 Jun 2023

Cited by 3 | Viewed by 1730

Abstract

The Spectacled Fulvetta (Fulvetta ruficapilla sordidior) is an endemic bird species to the southwest mountains of China, distributing from 1250 to 2500 m in the widespread broadleaved evergreen forest and occasionally in secondary scrubs. The present study describes its breeding biology for the first time. Fieldwork was conducted in the springs of 2017 and 2018 on Humashan Mountain, a hill mainly covered by secondary forest located at the eastern marginal of Kunming, the capital of Yunnan Province in Southwest China. This bird was found to initiate egg-laying mainly in March, and most nestlings fledged in late April and May. There were 16 nests found in total, which were located mainly in the dense shrubs at a height of 0.99 ± 0.40 m (n = 15). Of the 11 active nests, clutch size averaged 2.73 ± 0.45 (n = 11). Focal observations were made on nests; the incubation lasted for 13.67 ± 0.47 days (n = 3) with a notably high nest attendance, i.e., eggs were incubated 84.23% of the observation time. Nestlings fledged at 13.00 ± 0.71 days (n = 4), and parents feeding frequency increased as the nestlings grew. Overall, the cumulative hatching and fledgling rates were 71.43% and 35.71%, resulting in a nesting success rate of 45.45%. Full article

(This article belongs to the Special Issue Recent Advances in Bird Diversity from Mountains and Lakes)

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18 pages, 9168 KiB

Open AccessArticle

Synthesis of the Energy-Saving Dry Dual Clutch Control Mechanism

by Nikolay Sergienko, Pavel Kalinin, Ivan Pavlenko, Marek Ochowiak, Vitalii Ivanov, Anton Sergienko, Natalia Pavlova, Yevheniia Basova, Oksana Titarenko, Aleksandr Nazarov, Andżelika Krupińska, Magdalena Matuszak and Sylwia Włodarczak

Appl. Sci. 2023, 13(2), 829; https://doi.org/10.3390/app13020829 - 6 Jan 2023

Cited by 9 | Viewed by 2819

Abstract

A promising direction in developing up-to-date transport vehicles is the use of transmissions, an essential element of which is a dual-clutch. Improving functional performance, energy efficiency, and environmental friendliness are relevant and require appropriate research. The object of study is a dry dual-clutch working with a manual transmission with high energy efficiency. In the proposed design scheme, a rotary lever and a movable carriage can change the structural diagram of the force interaction between the pressure spring and the clutch discs. The developed mathematical model of the clutches control mechanism allowed for analyzing the process of controlling the dual-clutch transmissions (DCT) and obtaining functional dependencies between pushing forces in friction pairs and the carriage position. As a result, a method for synthesizing DCT was proposed to ensure the transmission of a given torque. Furthermore, it was determined and numerically proven that the same radial movement of the carriage when switching-on the clutches does not guarantee equal loading for the frictional discs of each clutch. This fact increases the uneven dynamics of torque and disc wear. Overall, the synthesis of the energy-saving dry dual-clutch control mechanism providing the same clutch margin for each clutch was developed. The method can be generalized and applied to designing dry dual-clutch transmissions for machines of various purposes. Full article

(This article belongs to the Special Issue Renewable Energy Systems 2023)

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