Meshing principle and characteristics analysis of an abnormal cycloidal internal gear transmission

Jingyu Mo,Shanming Luo,Shengping Fu,Xuefeng Chang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

A novel 2K-H internal meshing abnormal cycloidal gear (ACG) planetary reducer is proposed to tackle the rotor vector (RV) reducer problems, such as complex overpositioning structure, high manufacturing and assembly accuracy requirements. The composite tooth profile of epicycloid-involute-hypocycloid is adopted as the tooth profile of the reducer. The aim of this study was to investigate the meshing principle of such gear and evaluate its transmission characteristics. The meshing principle of tooth profile of the ACG is described. According to the gear geometry theory, the mathematical model of conjugate tooth profile of ACG pair was derived based on the contact path. And the influence of design parameters on the ACG tooth profile were also carried out. Moreover, the non-interference condition of the ACG pair was derived, and then meshing characteristics of the ACG pair were analyzed by numerical example, such as contact ratio, sliding ratio, and meshing efficiency. The bending and contact stresses of the ACG pair were also evaluated by comparing with those of involute pair. The results show that, the ACG has good transmission characteristics, such as small sliding ratio, high transmission efficiency. Compared with the involute gear, the bending and contact stresses of the ACG are reduced. The study lays a theoretical foundation for the optimization design of the ACG and the improved reliability of the ACG reducer.

Calibration Method of Roof Weld Coating Robot System Based on Plane-to-Plane Intersection Model

Shanming Luo,Fuqiang Li,Pingjiang Wang,Yin Yang,Jingyu Mo 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.8

In order to solve the problems of traditional calibration methods, such as assigning internal and external parameters for camera and hand-eye relation matrices, a new method to calibrate weld coating robots based on plane-to-plane intersection model is developed in this paper. The mathematical model of the system is established by the homogeneous transformation theory, and then used to calibrate the line structured light sensor (LSLS). By adjusting the robot, the coordinate systems of the LSLS and the workpiece are superposed to solve the hand-eye relation matrix of the car roof weld coating robot. Finally, the calibrated experimental process and results towards car roof weld coating robot system are analyzed. The results show that this method is simple and high accuracy in roof weld coating robot system, and can be applied to the field calibration of car roof weld coating robot system. Furthermore, it can provide guiding significance for calibration of other robot systems.

Research on vibration control of a transmission tower-line system using SMA-BTMD subjected to wind load

Li Tian,Jingyu Luo,Mengyao Zhou,Wenzhe Bi,Yuping Liu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.5

As a vital component of power grids, long-span transmission tower-line systems are vulnerable to wind load excitation due to their high flexibility and low structural damping. Therefore, it is essential to reduce wind-induced responses of tower-line coupling systems to ensure their safe and reliable operation. To this end, a shape memory alloy-bidirectional tuned mass damper (SMA-BTMD) is proposed in this study to reduce wind-induced vibrations of long-span transmission tower-line systems. A 1220 m Songhua River long-span transmission system is selected as the primary structure and modeled using ANSYS software. The vibration suppression performance of an optimized SMA-BTMD attached to the transmission tower is evaluated and compared with the effects of a conventional bidirectional tuned mass damper. Furthermore, the impacts of frequency ratios and SMA composition on the vibration reduction performance of the SMA-BTMD are evaluated. The results show that the SMA-BTMD provides superior vibration control of the long-span transmission tower-line system. In addition, changes in frequency ratios and SMA composition have a substantial impact on the vibration suppression effects of the SMABTMD. This research can provide a reference for the practical engineering application of the SMA-BTMD developed in this study.

Boron defect engineering in boron nitride nanosheets with improved adsorptive desulfurization performance

Jun Xiong,Jing Luo,Lei Yang,Jingyu Pang,Wenshuai Zhu,Huaming Li 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.64 No.-

Boron defect engineered boron nitride (BN) nanosheets have been prepared with the barbituric acid as co-reactant sources. By virtue of B defects, the electronic structure of BN undergo significantly variation, in which the conduction band of BN declined from −1.35 to −0.54 eV and decreased chemical acid hardness. After B defect engineering, BN nanosheets display greatly improved adsorptive desulfurization performance towards dibenzothiophene (DBT), with optimized adsorption capacity of 43.6 mgS g−1 for model oil. The increased adsorptive desulfurization performance was derived from decreased chemical acid hardness by B defect engineering, thus can build preferable interplay between the soft base DBT.

Impaired Voluntary Wheel Running Behavior in the Unilateral 6-Hydroxydopamine Rat Model of Parkinson's Disease

Pan, Qi,Zhang, Wangming,Wang, Jinyan,Luo, Fei,Chang, Jingyu,Xu, Ruxiang The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.57 No.2

Objective : The aim of this study was to investigate voluntary wheel running behavior in the unilateral 6-hydroxydopamine (6-OHDA) rat model. Methods : Male Sprague-Dawley rats were assigned to 2 groups : 6-OHDA group (n=17) and control group (n=8). The unilateral 6-OHDA rat model was induced by injection of 6-OHDA into unilateral medial forebrain bundle using a stereotaxic instrument. Voluntary wheel running activity was assessed per day in successfully lesioned rats (n=10) and control rats. Each behavioral test lasted an hour. The following parameters were investigated during behavioral tests : the number of running bouts, the distance moved in the wheel, average peak speed in running bouts and average duration from the running start to the peak speed. Results : The number of running bouts and the distance moved in the wheel were significantly decreased in successfully lesioned rats compared with control rats. In addition, average peak speed in running bouts was decreased, and average duration from the running start to the peak speed was increased in lesioned animals, which might indicate motor deficits in these rats. These behavioral changes were still observed 42 days after lesion. Conclusion : Voluntary wheel running behavior is impaired in the unilateral 6-OHDA rat model and may represent a useful tool to quantify motor deficits in this model.

DRAG REDUCTION PREDICTION OF AHMED MODEL WITH TRAVELING WAVE BASED ON BP NEURAL NETWORK

Hu Xingjun Hu,Jinglong Zhang,Yufei Luo,Jingyu Wang,Pengzhan Ma,Wei Lan,Chunbo Dong 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.5

In this paper, a traveling wave model is proposed to explore its influence on the aerodynamic drag of a Ahmed model, the experimental and numerical results of aerodynamic drag coefficient CD for the Ahmed model are in good agreement. Then by defining the aerodynamic benefit coefficient ΔCD as the evaluation index for the orthogonal experiment, range analysis is conducted to determine the influences of the amplitude A, wavelength λ and frequency ω of the wave and the vehicle speed u on ΔCD. After the analysis it can been found that λ has the least importance among these parameters, hence A, ω and u are used to construct the 105 samples for training the BP neural network to predict ΔCD, results show that ΔCD obtained from the neural network is significantly affected by the parameters of traveling wave. The prediction accuracy of the network is furtherly verified by another 15 samples which are also built on A, ω and u, and the corresponding data overlap rate of ΔCD is 96 %, so it can be concluded that the BP neural network constructed in this paper is accurate enough to predict ΔCD.

Flow control of automobile with plasma vortex generator

Xingjun Hu,Jinglong Zhang,Zheng Hui,Yufei Luo,Peng Guo,Jingyu Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

In this study, a plasma actuator was used to examine the wake flow control of an automobile with the aid of wind tunnel test methods, such as surface pressure measurement and particle image velocimetry (PIV) measurement. The control mechanism and law of the plasma vortex generator in the wake field of an Ahmed model were described. The effects of certain factors were analyzed. Results showed that the streamwise vortex induced by a dielectric-barrier-discharge vortex generator (DBD-VG) could promote the mixing of high-speed airflow above the slanted surface at the end of the model and low-speed airflow near the wall by increasing airflow turbulence, thereby inhibiting the generation of separation bubbles and reducing drag. Drag reduction decreased as the total discharge length of the DBD-VG decreased, but its backward distance had the largest effect on the drag reduction rate, followed by its counter distance. Meanwhile, the shortening of the streamwise length had the least effect on the drag reduction rate. When installing the DBG-VG, the end of the actuator should be arranged near the separation line to enable the generation and development of the streamwise vortex before the separation line to achieve the strongest flow control effect. The DBD-VG need not be arranged precisely at the airflow separation point, which demonstrates its favorable versatility. At low speeds, a maximum drag reduction rate of -8.51 % was obtained at an excitation voltage of 13 kV under the control of the DBD-VG, which demonstrated its strong flow control capability.

miR-148b-3p, miR-190b, and miR-429 Regulate Cell Progression and Act as Potential Biomarkers for Breast Cancer

Wenzhu Dai,Jixiang He,Ling Zheng,Mingyu Bi,Fei Hu,Minju Chen,Heng Niu,Jingyu Yang,Ying Luo,Wenru Tang,Miaomiao Sheng 한국유방암학회 2019 Journal of breast cancer Vol.22 No.2

Purpose: Breast cancer is the most frequently diagnosed malignancy in women worldwide. MicroRNAs (miRNAs) are thought to serve as potential biomarkers in various cancers, including breast cancer. Methods: We evaluated the miRNA expression profiles in 1,083 breast cancer samples and 104 normal breast tissues from The Cancer Genome Atlas database. We used the edgeR package of R software to analyze the differentially expressed miRNAs in normal and cancer tissues, and screened survival-related miRNAs by Kaplan-Meier analysis. A receiver operating characteristic curve was generated to evaluate the accuracy of these miRNAs as molecular markers for breast cancer diagnosis. Furthermore, the functional role of these miRNAs was verified using cell experiments. Targets of candidate miRNAs were predicted using 9 online databases, and Gene Ontology (GO) functional annotation and pathway analyses were conducted using Database for Annotation, Visualization and Integrated Discovery online tool. Results: A total of 68 miRNAs showed significantly different expression patterns between the groups (p < 0.001), and 13 of these miRNAs were significantly associated with poor survival (p < 0.05). Three miRNAs with high specificity and sensitivity, namely, miR-148b-3p, miR-190b, and miR-429, were selected. In vitro experiments showed that the overexpression of these 3 miRNAs significantly promoted the proliferation and migration of MDA-MB-468 and T47D cells and reduced the apoptosis of T47D cells. GO and pathway enrichment analyses revealed that the targets of these dysregulated miRNAs were involved in many critical cancer-related biological processes and pathways. Conclusion: The miR-148b-3p, miR-190b, and miR-429 may serve as potential diagnostic and prognostic markers for breast cancer. This study demonstrated the roles of these 3 miRNAs in the initiation and progression of breast cancer.