Profile shift is a highly effective technique for optimizing the performance of spur gear transmission systems.However,tooth surface wear is inevitable during gear meshing due to inadequate lubrication and long-term o...Profile shift is a highly effective technique for optimizing the performance of spur gear transmission systems.However,tooth surface wear is inevitable during gear meshing due to inadequate lubrication and long-term operation.Both profile shift and tooth surface wear(TSW)can impact the meshing characteristics by altering the involute tooth profile.In this study,a tooth stiffness model of spur gears that incorporates profile shift,TSW,tooth deformation,tooth contact deformation,fillet-foundation deformation,and gear body structure coupling is established.This model efficiently and accurately determines the time-varying mesh stiffness(TVMS).Additionally,an improved wear depth prediction method for spur gears is developed,which takes into consideration the mutually prime teeth numbers and more accurately reflects actual gear meshing conditions.Results show that consideration of the mutual prime of teeth numbers will have a certain impact on the TSW process.Furthermore,the finite element method(FEM)is employed to accurately verify the values of TVMS and load sharing ratio(LSR)of profile-shifted gears and worn gears.This study quantitatively analyzes the effect of profile shift on the surface wear process,which suggests that gear profile shift can partially alleviate the negative effects of TSW.The contribution of this study provides valuable insights into the design and maintenance of spur gear systems.展开更多
针对秦沈客运专线担当牵引任务的电力机车TVM430监控系统,限速值只有160 km/h和120 km/h 2种,而我国列车牵引限速有160 km/h、140 km/h和120 km/h 3种的现状,提出研究一种限速值为140 km/h的装置作为补充,以满足机车牵引限速的要求。介...针对秦沈客运专线担当牵引任务的电力机车TVM430监控系统,限速值只有160 km/h和120 km/h 2种,而我国列车牵引限速有160 km/h、140 km/h和120 km/h 3种的现状,提出研究一种限速值为140 km/h的装置作为补充,以满足机车牵引限速的要求。介绍了该限速报警监控仪方案及软硬件组成。基于该研究成果研制的样机已通过上车试运行,取得良好效果。展开更多
基金Supported by National Natural Science Foundation of China (Grant No.52275061)。
文摘Profile shift is a highly effective technique for optimizing the performance of spur gear transmission systems.However,tooth surface wear is inevitable during gear meshing due to inadequate lubrication and long-term operation.Both profile shift and tooth surface wear(TSW)can impact the meshing characteristics by altering the involute tooth profile.In this study,a tooth stiffness model of spur gears that incorporates profile shift,TSW,tooth deformation,tooth contact deformation,fillet-foundation deformation,and gear body structure coupling is established.This model efficiently and accurately determines the time-varying mesh stiffness(TVMS).Additionally,an improved wear depth prediction method for spur gears is developed,which takes into consideration the mutually prime teeth numbers and more accurately reflects actual gear meshing conditions.Results show that consideration of the mutual prime of teeth numbers will have a certain impact on the TSW process.Furthermore,the finite element method(FEM)is employed to accurately verify the values of TVMS and load sharing ratio(LSR)of profile-shifted gears and worn gears.This study quantitatively analyzes the effect of profile shift on the surface wear process,which suggests that gear profile shift can partially alleviate the negative effects of TSW.The contribution of this study provides valuable insights into the design and maintenance of spur gear systems.
文摘近几十年来,世界各军事强国竞相发展隐身技术,战机典型RCS已经从0.1~1 m^(2)下降到-40 dBm^(2),隐身目标探测成为空空导弹雷达导引头领域亟待解决的难题,有源相控阵导引头技术被广泛认为是最有可能解决空空导弹对隐身目标探测的先进技术,但成本高,且对隐身目标探测能力提升有限。本文结合美军近年来中距空空导弹改进项目以及从平台中心战转向网络中心战、体系中心战的大背景,通过对机载雷达、TVM(Track via Missile)雷达导引头以及Ku和Ka波段主动雷达导引头在晴天和雨天条件下对典型隐身目标探测距离计算分析的基础上,认为美军可能在发展TVM雷达制导与主动雷达制导复合的制导方式。X波段TVM雷达导引头技术可以充分利用机载雷达资源,提升导引头对隐身目标探测能力,相比有源相控阵导引头技术成本大幅度降低。
文摘针对秦沈客运专线担当牵引任务的电力机车TVM430监控系统,限速值只有160 km/h和120 km/h 2种,而我国列车牵引限速有160 km/h、140 km/h和120 km/h 3种的现状,提出研究一种限速值为140 km/h的装置作为补充,以满足机车牵引限速的要求。介绍了该限速报警监控仪方案及软硬件组成。基于该研究成果研制的样机已通过上车试运行,取得良好效果。
