大功率液力机械器是重型特种车辆传动系统的关键核心部件,为满足整车高速、重载和高任务可靠性的使用要求,一方面需要提升液力机械变速器自身的强度和可靠性,另一方面要建立和完善大功率液力机械变速器的状态监测和故障诊断系统;基于专家系统和典型零部件的失效物理模型,针对液力机械变速箱系统和关键零部件的常见失效形式,建立了大功率液力机械变速器状态监测和故障诊断系统,分为变矩与闭锁功能监测及报警模块、换挡提示及报警模块、油位监测及报警模块、系统油压监测及报警模块和油温监测及报警模块共五大部分;通过实车测试证明,大功率液力机械变速器状态监测和故障诊断系统能够较为有效的识别系统的潜在失效和使用风险,或在出现严重故障前,通过简单的维护和保养,避免严重故障的发生,从而减少人力和零备件的需求,降低保障费用.

目的 调查现役飞行人员视网膜周边退行性变性的患病情况,为招飞体检和飞行人员医学鉴定标准提供数据支持.方法 采用Daytona P200T设备,对2019年10月～12月在某疗养院疗养的562名飞行人员进行眼底图像采集,每眼采集正前方、鼻侧、颞侧、上方、下方5个方位4个眼底周边视网膜图像,检查其视网膜周边退行性变性患病情况,并对检查结果按照年龄、飞行时间、机型进行分组统计分析.结果 562名受检飞行人员中有93人存在不同类型视网膜周边退行性变性,其中视网膜周边非压迫性白为8.01％;视网膜周边囊样变性为3.74％,视网膜周边干性裂孔为1.96％、视网膜周边格子样变性为1.96％,视网膜周边蜗牛足迹变性为0.53％,视网膜周边马蹄形裂孔为0.18％,视网膜铺路石样变性为0.18％,总患病率为16.55％;视网膜周边退行性变性与年龄、飞行时间和机型之间没有相关关系.结论 年度体检合格的飞行人员人群中视网膜周边退行性变性仍有一定的患病率,视网膜周边退行性变性及其类型对飞行安全的潜在影响仍需要进一步评估.

大功率分动器作为某多轴超重型底盘传动系统的关键部件,具有传递转矩大、转速高、环境温差大等特点,单纯依靠飞溅润滑和自然风冷散热已无法满足多轴超重型底盘高机动性、高越野性和极限环境温度的使用需求,需采用强制润滑系统对分动器内部各产热点尤其是轴承位置进行润滑.因此,首先建立了传动部件各产热点的功率热能模型,通过热平衡条件估计各润滑点和总体的流量需求,然后建立液压仿真分析模型,设计匹配润滑系统管路;同时,针对动力传动系统功率大,自然风冷散热无法满足分动器热平衡要求的问题,通过计算分动器的表面风速、散热表面积评估分动器箱体自身的散热能力,并根据散热量需求匹配外置的风冷散热器和风扇.最后,通过台架和跑车试验,验证了所设计的大功率分动器强制润滑散热系统能够满足某多轴超重型底盘的各项使用要求.

轮边变速器是多轴超重型混合动力试验平台的关键部件,由于应用场合的特殊性,一方面要求轮边变速器能够满足整车的动力性要求,同时又要满足轻质和高可靠性要求.因此,在轮边变速器的方案设计中,以轻量化为目标,以可靠性为约束条件,提出轮边变速器齿轮的优化设计方案.经高速试验、全载疲劳试验和过载疲劳试验验证,轮边变速器的性能与可靠性满足多轴超重型混合动力试验平台的使用要求.

Objective To investigate the ocular fundus disease in flying personnel and explore the application of multi-spectral fundus imaging in aviation medical identification.Methods The fundus data of 213 flight personnel were collected by multi-spectral imaging.They were divided into different groups by age and by flying time.The prevalence of abnormal ocular fundus was analyzed upon age and flying time.In order to discuss the possible risk factors leading to arteriosclerotic retinopathy,we used the method of paired design for the comparison between the hyperlipidemia flying personnel and the normal blood lipid flying personnel,or fighter pilots (high +-Gz exposed) and other flying personnel.Results The total prevalence of abnormal ocular fundus in 213 flying personnel was 13.15％.In which,the prevalence of retinal arteriosclerosis was 5.16％,took the first,retinal pigmentation disorder was 3.29％ and maculopathy was 2.35％.The prevalence of abnormal ocular fundus showed increasing trend with age and flying time.Besides,the prevalence of arteriosclerotic retinopathy in the group of hyperlipidemia was higher than that of normal blood lipid group.But there were no significant differences between high + Gx exposed pilots and other flying personnel.Conclusions Multi-spectral imaging is a convenient and objective method for recording retinal changes.It is applicable to the physical examination and screening of flying personnel.

基于GT-Suite软件建立了某超重型多轴驱动特种车动力传动系统的非归一化多分支扭振力学模型.仿真分析了车辆在驻车变速箱空挡、驻车分动器空挡和车辆行驶3种工况下的扭转固有模态;通过试验获得了以上3种工况下系统的扭转固有模态.对比驻车变速箱空挡工况与驻车分动器工况可知,在联轴器隔振效果较好的情况下,变速箱对发动机的扭振特性影响不大.固有频率在驻车工况和行车工况下会发生偏移,因此,车辆设计时需要同时考虑两种工况.

A numerical analysis of an oil-lubricated spiral grooved upstream pumping face seal, accounting for the occurrence of cavitation, have been performed in this paper. The “equivalent flow model”, which is a theoretical scheme for taking the JFO boundary condition into hydrodynamic lubrication theory, was applied to the analyses by a finite difference treatment of the Reynolds equation that dealt with the geometry of logarithmic spiral groove. The calculated results were compared respectively based on Reynolds model and JFO model. The load capacity, cavitation ratio, frictional torque and leakage rate were also theoretically calculated. The difference between the theoretical results based on two boundary conditions for cavitation occurrence is considerable. The JFO boundary condition should be used in theoretical studies on sealing characteristics rather than Reynolds equation, especially in the conditions of less groove depth and high rotary speed.

本文简要介绍了虚拟试验验证技术在HTF多轴特种车上的应用,包括特种车试验测试介绍,刚柔液联合仿真动正文>=力学模型建立,轴头激励数据重构,虚拟试验结果与试验测试结果的比对,虚拟试验验证技术应用于驾驶室悬置系统的优化. 1 前言 HTF系列特种车是重型运载车辆,已经研发出四轴到八轴的自行式车辆产品,承载质量从30 ～ 100t.车架为高断面折弯型高强度刚度贯通梁,采用高强度钢材料;为了提高越野性能,特种车辆采用了大尺寸宽断面轮胎,轮胎直经为1500mm;悬架系统为液压式连通式油气弹簧,具有很高的平顺性和越野性能.

Aiming at solving the sintering problem of needle roller bearing of a high power transfer box due to high local temperature,a calculation and analysis model of the needle roller bearing is established.Besides,its bearing capacity and rated revolutions per minute are calculated.A new design and improvement plan for the bearing is put forward on the premise of making as minor changes as possible to the original structure of the transfer box.Then bearing capacity analysis and heat balance calculation of the new proposal are carried out.Results show that the improved needle roller bearing and lubrication circuit are able to meet the radiating demand of high power transfer box,thus avoiding the risk of sintering owing to low rated revolutions per minute and insufficient supply of lubrication oil locally of the original bearing.