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关键词： Clutch sleeve   Clutch shell   Leakage   Finite element method   Mathematical model  

摘要： To solve leakage failure of the product caused by uncertain factors, the clutch sleeve and shell are taken as an example for development of processing. Finite element model of clutch sleeve and shell is established, and the stress deformation is ascertained and analyzed under working load. Based on actual operating conditions of the clutch sleeve and shell, the mathematical model of leakage failure is established considering the factors of load, temperature, manufacturing error and assembling deviation. The clearance between the clutch sleeve and shell is determined and discussed using the model based on the influence of various factors. To reduce the size of the clearance, a relevant improvement that the increased step is added on outside of the sleeve is put forward. The results of discussion on the improved assembly and analysis of actual samples prove that the scheme is effective.

关键词： cooperative breeding   Crotophaga ani   egg coloration   egg manipulation   ovicide   reproductive competition   Smooth-billed Ani  

摘要： Reproductive competition in the form of ovicide is common in some joint-nesting birds, species in which multiple females lay eggs in a single nest. Joint-nesting Smooth-billed Anis (Crotophaga ani) often bury eggs under a new nest floor prior to laying their own eggs. Anis apparently cannot recognize their own eggs, which raises the question of how individuals can minimize their loss of young due to egg burial or consequences of hatching asynchrony. Newly laid eggs are coated with a white layer of vaterite (calcium) while older eggs may be almost entirely blue. Leaving older, bluer eggs in the nest presumably leads to a more competitive nest environment for the female's own young because newer eggs hatch later, producing smaller chicks at risk of getting trampled or bumped out of the nest. We hypothesized that Smooth-billed Anis use egg color as a cue for egg age. We predicted females not yet laying would bury older-looking blue eggs and tested this by removing the vaterite layer from all eggs in selected nests. Contrary to our prediction, altering egg color of whole clutches to make them look bluer, and thus older, did not trigger egg burial. The number of eggs buried increased with increasing female group size, however, consistent with previous work on this species.

关键词： Saturation magnetization  

摘要： This paper presents the synthesis and realization of the C-axis textured M-type barium ferrite BaScxFe12-xO19 (x = 0.1, 0.3, 0.6, 0.8, 1.0) using the solid-state method. Among this samples, the BaScxFe12-xO19 with x = 0.1 ferrite exhibits preferable magnetic properties with the saturation magnetization of similar to 4700 Gauss and squareness ratio of 0.65, which is suited for the realization of self-biased circulator design. Results of the SEM reveal that the Sc3+ has negligible effect on the crystal morphology. The measured results for the vibrating sample magnetometer indicate that increasing x of the induced Sc3+ yields decreasing the magneto-crystalline anisotropy field, saturation magnetization, coercivity, and reduces the squareness ratio. Besides, influence of Sc3+ on dielectric constant also have be investigated.

关键词： Four-wheel-drive HEV with DCT   Mode transition   Multistage optimal control   Sliding-mode control   Double tracking control architecture  

摘要： When the four-wheel-drive hybrid electric vehicle (HEV) equipped with a dry dual clutch transmission (DCT) is in the mode transition process from pure electrical rear wheel drive to front wheel drive with engine or hybrid drive, the problem of vehicle longitudinal jerk is prominent. A mode transition robust control algorithm which resists external disturbance and model parameter fluctuation has been developed, by taking full advantage of fast and accurate torque (or speed) response of three electrical power sources and getting the clutch of DCT fully involved in the mode transition process. Firstly, models of key components of driveline system have been established, and the model of five-degrees-of-freedom vehicle longitudinal dynamics has been built by using a Uni-Tire model. Next, a multistage optimal control method has been produced to realize the decision of engine torque and clutch transmitted torque. The sliding-mode control strategy for measurable disturbance has been proposed at the stage of engine speed dragged up. Meanwhile, the double tracking control architecture that integrates the model calculating feedforward control with Hoo robust feedback control has been presented at the stage of speed synchronization. Finally, the results from Matlab/Simulink software and hardware-in-the-loop test both demonstrate that the proposed control strategy for mode transition can not only coordinate the torque among different power sources and clutch while minimizing vehicle longitudinal jerk, but also provide strong robustness to model uncertainties and external disturbance. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： KISSsoft   齿轮传动   设计  

摘要： 本文对塑料齿轮转动系统的作用进行了介绍,并且分析了KISSsoft软件的功能,基于KISSsoft软件进行了齿轮传动系统的设计,并对相应的计算结果进行了分析,为进一步的优化设计提供了理论依据。

关键词： 离合器   膜片弹簧   变形   强压   喷丸  

摘要： 本文通过分析常规的膜片弹簧离合器结构特点、膜片弹簧制造工艺以及失效的原因,通过优化设计来提高膜片弹簧力值稳定和使用寿命。

关键词： 30CrSiMoVM钢   铜基粉末冶金   高温   摩擦磨损性能  

摘要： 为了探讨离合器摩擦副材料在高温下的摩擦磨损机制,采用30CrSiMoVM钢作为与铜基粉末冶金摩擦片配对使用的对偶钢片,在MMU-10G高温端面摩擦磨损试验机上,研究30CrSiMoVM钢和摩擦片组成的摩擦副在室温到600℃之间的摩擦磨损性能。研究结果表明:随着温度升高,材料的强度逐渐降低,摩擦界面氧化膜不断形成与脱落,使摩擦副摩擦因数和磨损量总体趋势逐渐增大。在温度为300~500℃时,摩擦副摩擦因数和磨损量均平稳增大,表明摩擦副材料在此温度段摩擦磨损性能较稳定,磨损机制表现为磨粒磨损、氧化磨损和疲劳磨损;在600℃时,摩擦副材料表层软化,摩擦片摩擦因数和磨损量急剧增大,对偶钢片因表层黏着磨损严重,相对磨损量较小,磨损机制表现为黏着磨损、氧化磨损和疲劳磨损。