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关键词： 自动变速器   行星齿轮传动机构   换挡执行机构  

摘要： 本文以拉维娜式四挡自动变速器为例,完成该自动变速器的传动机构设计,包括各个挡位传动路线及其传动方案设计,最终通过给定具体参数,完成整个行星齿轮传动部分的结构设计。

关键词： 离合器   离合操纵   校核  

摘要： 在整车开发前期,因为离合器系统关系到整车操控的舒适性,所以其匹配开发工作显得尤为重要。文章针对上汽通用五菱汽车股份有限公司某新开发轿车车型的离合器及离合操纵系统进行设计校核,校核离合器摩擦功、后备系数、起步温升、离合踏板力及离合踏板行程等相关设计参数。

关键词： 大型养路机械   钢轨打磨车   减速箱脱齿   现场试验   离合器   脱齿工装  

摘要： GMC96B钢轨打磨车在作业时要对A车减速箱进行合齿实现低速液压传动,作业结束后减速箱脱齿实现高速液力走行。在现场使用中出现了由各种因素导致的作业结束后减速箱无法脱齿的故障,受现场封锁时间限制,若故障无法及时查找并处理时将严重影响正常行车,导致列车晚点。本文分析了减速箱无法脱齿的原因,针对各故障提出了相应的解决方案,并研制了可快速完成减速箱脱齿的工装,通过现场实际应用,有效地解决了减速箱故障处理难题,确保了打磨车的运行安全。

关键词： 中重卡   离合器   离合器操纵机构  

摘要： 某中重卡车型匹配的离合器存在批量早期烧蚀故障,文章对离合器与离合器操纵机构匹配情况进行了理论计算及结构分析,通过改进离合器操纵机构,解决了离合器市场故障。

关键词： 双离合器自动变速器   换挡控制   模糊控制   换挡品质   仿真  

摘要： 为提高双离合器式自动变速器的换挡质量,研究换挡过程中双离合器的协调控制方法。分析了双离合器自动变速器的结构和动力传递路线,并建立传动系统的数学模型。综合考虑整车动力性、经济性和换挡平顺性等因素,采用模糊控制理论设计了综合智能型的换挡策略。以MATLAB/Simulink/Stateflow为软件平台,开发动力传动系统的仿真模型并对换挡过程进行仿真试验。结果表明,该策略可以较好地减少换挡时间和缓和冲击度,优化了换挡品质。

关键词： Conspecific superparasitism   Host discrimination   Multiple-egg clutches   Quasi-gregarious   Self-superparasitism   ADAPTIVE SELF-SUPERPARASITISM   GYPSY-MOTH   CONSPECIFIC SUPERPARASITISM   SOLITARY PARASITOIDS   HOST DISCRIMINATION   NATURAL ENEMIES   TIME ALLOCATION   SEX ALLOCATION   HYMENOPTERA   SIZE  

摘要： In the quasi-gregarious parasitoid wasp Anastatus disparis, a mother may lay more than one egg in a host during a single host encounter. This is conventionally known as self-superparasitism and, since only one adult offspring can complete development on the host, it may represent a waste of eggs and time. However, this behavior may be better described as "multiple-egg clutches," which differs fundamentally from self-superparasitism and has seldom been addressed. The potential benefits of laying multiple-egg clutches are currently unclear, and we therefore aimed to investigate them in A. disparis. First, our results showed that production of multiple-egg clutches by A. disparis is not due to a lack of discrimination between unparasitized and parasitized hosts, as females preferred to lay eggs in unparasitized hosts. It was also unrelated to the age of the female or her mating status, or to the presence of conspecific females. However, compared to the temperatures of 26 and 32 degrees C, we observed that the frequency of multiple-egg clutches increased at the temperature of 20 degrees C. In addition, low developmental temperatures significantly decreased the rate of successful wasp eclosion from hosts in which a single egg was deposited, and this rate was increased by laying multiple-egg clutches. These results suggest that female A. disparis adults produce multiple-egg clutches to increase the probability of obtaining offspring from the host, and may have the ability to regulate oviposition and reproduction strategy based on environmental temperature. Significance statement Anastatus disparis exhibited an oviposition behavior of facultative production of multiple-egg clutches, which is not due to a lack of host discrimination, or due to the age of the female or her mating status nor the presence of conspecific females. However, our results suggest that A. disparis adults produce multiple-egg clutches when it increased the probability of obtaining offspring from the h

关键词： Dual clutch transmission   Control-oriented model   Clutch torque estimation   Drive shaft torque estimation   Gear shift control   TRANSMITTED TORQUE   SHIFT CONTROL   ENGAGEMENT   DYNAMICS   SLIP  

摘要： Over the years, dual-clutch transmission (DCT) has demonstrated its higher efficiency and superior shift performances over other types of transmissions, and has been increasingly used in modern mass-produced vehicles. However, due to the absence of the smoothing effects of torque converters, vehicles with DCT are easily exposed to driveline oscillations that lead to poor driving quality, especially during gear shifts. Therefore, torque transfer through the driveline should be controlled with great care by two clutches and engine to achieve the DCT's outstanding performance. The main obstacle to the accurate torque control is its lack of adequate sensors in production vehicles. Thus, the objectives of this paper are two-fold. First, a control-oriented model with practical concerns is implemented for DCT drivelines, aiming to accurately describe the powertrain oscillations that should be suppressed by the torque control. Secondly, a real-time torque monitoring strategy based on the proposed model is suggested to deal with the absence of torque sensors. The primary task of the torque estimator is to concurrently estimate the torque transmitted through both clutches and drive shaft by using only readily available data from production cars. The developed torque estimator is verified through multiple experiments under various driving conditions. (c) 2017 Elsevier Ltd. All rights reserved.

关键词： Dual input transmission   Clutchless automated manual transmission   Electric vehicle   Shift control   Noise vibration and harshness   AUTOMATED MANUAL TRANSMISSION   SYNCHRONIZER MECHANISMS   MOTOR   OPTIMIZATION   HYBRID   TORQUE  

摘要： The purpose of this paper is to study the practical application of a two motor electric vehicle powertrain utilizing a combination of fixed and multiple speed gear ratios. To realize power-on shifting without torque hole and maximize overall efficiency, a high-speed motor is adopted as the primary motor connecting to the multiple speed clutchless automated manual transmission and a low-speed high torque electric motor is employed as the assisting motor connected to the final shaft with fixed gear ratio. Motor torque and speed are controlled using improved model predictive flux control method in conjunction with synchronizer mechanism actuation to best fill the torque hole to improve both drivability and driving comfort. To evaluate the proposed system, a complete mathematical model is built and compared with a conventional single motor transmission system. The detailed transient dynamic results in terms of final shaft torque, acceleration and vehicle jerk demonstrate the effectiveness of the proposed powertrain. (c) 2017 Elsevier Ltd. All rights reserved.

关键词： Thyroid hormones   Sucrose   Non-nutritive sweeteners   Sucralose   GLUCAGON-LIKE PEPTIDE-1   FASTING-INDUCED CHANGES   VENTRAL TEGMENTAL AREA   TASTE RECEPTOR   ARTIFICIAL SWEETENER   NONNUTRITIVE SWEETENERS   ENVIRONMENTAL CHEMICALS   ENERGY-EXPENDITURE   HORMONE-LEVELS   BODY-WEIGHT  

摘要： Non-nutritive sweeteners are the most widely used food additives worldwide. However, their metabolic outcomes are still a matter of controversy and their effect on the thyroid activity, a key regulator of metabolism, has not been previously studied. Therefore, we aim to determine the influence of the sweet type flavour carrier on selected parameters of thyroid axis activity. Male Sprague-Dawley rats (n = 105) were divided into 3 groups fed ad libitum for three weeks isocaloric diets (3.76 +/- 0.5 kcal/g): two with the same sweet flavour intensity responded to 10% of sucrose (with sucrose-SC-and sucralose-SU) and one non-sweet diet (NS). To evaluate the post-ingested effects, animals were euthanised at fast and 30, 60, 120, 180 min after meal. The results obtained indicate that both the presence and the type of sweet taste flavour carrier affect thyroid axis activity both at fasting and postprandial state. Compared to diet with sucrose which stimulates thyroid axis activity, sucralose addition diminishes thyroid hormone synthesis as thyroid peroxidase (TPO) activity, plasma thyroxine (T4), and triiodothyronine (T3) concentration was lower than in SC and NS while in non-sweet diet the lowest level of hepatic deiodinase type 1 (DIO1) and the highest reverse T3 (rT3) level indicate on altered thyroid hormone peripheral metabolism. Both the presence and the type of sweet flavour carrier have a significant impact on thyroid axis activity. Our findings suggest that this organochlorine sweetener is metabolically active and might exacerbate metabolic disorders via an adverse effect on thyroid hormone metabolism.