共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
3.
4.
5.
6.
7.
1.故障现象
我公司生产的SER22/26系列旋挖钻机,连续发生多起液压油冷却器冷却风扇叶片折断故障,导致其无法正常施工。经检查,发现该风扇叶折断位置均在其根部(铆钉附近),如图1所示。 相似文献
8.
《机械工程与自动化》2020,(5)
针对某型涡轮动力装置铆钉断裂故障,通过分解检查和故障树排查,确定故障原因是中间齿轮组件出现铆接质量问题,铆接后中间小齿轮与中间大齿轮的轴线存在角度偏差,造成齿轮轴工作时出现轴向窜动并发生碰撞,一处铆钉疲劳断裂后,承力结构失稳,使其余两处铆钉过载断裂。为杜绝同类故障,增加了铆接后检查工序。 相似文献
9.
为了满足某型发动机风扇叶片振动应力试验需求,进行了基于Lab VIEW的风扇叶片振动应力采集软件设计。重点介绍了采集系统的组成及软件的设计,可实现整个数据采集流程的控制,完成数据的实时保存、时域波形的显示和频谱分析。通过风扇叶片振动应力试验,验证了采集软件设计的正确性及可靠性,为类似测量系统的设计提供借鉴。 相似文献
10.
11.
12.
以后置导叶型轴流通风机为模型,采用CFD方法对风机内部流场进行数值模拟,揭示了其内部流场的基本特征,进行了性能预测;并与其气动性能进行了对比分析。结果表明:采用CFD方法进行性能预测有较高的精度和可靠性,同时可为内部流动优化提供依据。 相似文献
13.
根据动(静)叶调节轴流通风机静态性能曲线的特点,对其参数进行了分析,提出了采用BP神经网络建立其静态性能模型.通过测试数据对所建模型进行了仿真试验,证明了该建模方法的可行性. 相似文献
14.
Fei Yan Daorong Xu S. C. Wu Qinde Sun Chunming Wang Yajun Wang 《Journal of Mechanical Science and Technology》2012,26(12):4089-4096
It has been mainly studied in this paper on brazing of Cu to Al using Al-Si filler metal. The optimized scanning rate of 2.5 mm/s is first obtained through simulating the temperature field of Cu-Al brazing process based on ANSYS software. Then the brazing of Cu-C11000 to Al-3003 using Al-Si-La-Sr filler is carried out by torch brazing technology. It is found that the brazing seam region is mainly consisted of α-Al solid solution and CuAl2 IMC. Further experimental results also show that the rare earth element La in filler metal can not only refine the grain, but also promote the dispersion of intermetallic compounds into the brazing seam, which significantly improves the brazing seam microstructure and mechanical properties of the joints. 相似文献
15.
通过铝板与复合板料碾铆连接与拉伸试验,分析了有无垫圈、不同预留高度及孔径对铝板与复合板料碾铆连接件连接质量的影响。试验结果表明:垫圈对抗拉伸性能影响最大,加垫圈试件比不加垫圈试件承载能力可提升50%左右;预留高度对连接性能有一定影响,随着预留高度增大,试件抗拉伸性能下降,预留高度为1mm和2mm时承载能力相差不大;孔径对连接强度影响较小,综合对比孔径分别为5.9、6.0、6.1mm试件可知,当孔径取6.0mm时试验结果较优。对钢铆钉进行了金相试验,从微观组织方面阐述了试件连接性能提升的机理。选取铜、铝铆钉进行碾铆及拉伸试验,所得结论相似。不同时间长度的腐蚀试验则表明较短时间内的硫酸溶液腐蚀对铆接件的拉伸性能影响较小。 相似文献
16.
G.W. Roper 《Tribology International》1982,15(3):145-151
The modified 3 in (76.2 mm) David Brown disc machine has been used to investigate the effect on scuffing performance of grinding away various amounts from the surface of nitrided steel discs. The results revealed a systematic deterioration in scuffing resistance as the surface nitrogen concentration decreased, but quantitative correlation between these parameters was hindered by the inadequacies of electron probe X-ray microanalysis as a tool for measuring low nitrogen concentrations. It was concluded that there is no safe depth to which Tenifer-treated (salt-bath nitrided) C15 steel can be ground without impairing its scuffing performance. Other disc tests were carried out to assess the effect on scuffing of phosphate treatment and oil formulation. Results showed that, while phosphate treatment is valuable when running against untreated steel, it is of no benefit against Tenifer-treated steel. On the other hand, the formulation of the lubricant was found to improve the scuffing resistance of Tenifer-treated steel 相似文献
17.
LI Deyou GONG Ruzhi WANG Hongjie XIANG Gaoming WEI Xianzhu QIN Daqing 《机械工程学报(英文版)》2016,29(4):803-812
The hump characteristic is one of the main problems for the stable operation of pump turbines in pump mode.However,traditional methods cannot reflect directly the energy dissipation in the hump region.In this paper,3D simulations are carried out using the SST k-ω turbulence model in pump mode under different guide vane openings.The numerical results agree with the experimental data.The entropy production theory is introduced to determine the flow losses in the whole passage,based on the numerical simulation.The variation of entropy production under different guide vane openings is presented.The results show that entropy production appears to be a wave,with peaks under different guide vane openings,which correspond to wave troughs in the external characteristic curves.Entropy production mainly happens in the runner,guide vanes and stay vanes for a pump turbine in pump mode.Finally,entropy production rate distribution in the runner,guide vanes and stay vanes is analyzed for four points under the 18 mm guide vane opening in the hump region.The analysis indicates that the losses of the runner and guide vanes lead to hump characteristics.In addition,the losses mainly occur in the runner inlet near the band and on the suction surface of the blades.In the guide vanes and stay vanes,the losses come from pressure surface of the guide vanes and the wake effects of the vanes.A new insight-entropy production analysis is carried out in this paper in order to find the causes of hump characteristics in a pump turbine,and it could provide some basic theoretical guidance for the loss analysis of hydraulic machinery. 相似文献
18.
为实现多层金刚石磨粒逐层激光钎焊成形,从单道扫描到单层扫描,再到多层扫描,系统研究了镍铬合金与金刚石磨粒的多层激光钎焊工艺。通过提取钎焊道与层的截面成形特征参量,对钎焊层截面成形质量进行参数化评价,并结合钎焊层表面形态,对钎焊层综合成形特性进行评价和讨论,研究了工艺参数对钎焊成形的影响。研究结果表明:激光功率与扫描速度是影响钎焊成形的重要因素,不仅影响着合金粉末的熔合程度、熔池宽度,还影响金刚石的分散状态和钎料对金刚石的浸润包裹性,最终影响钎焊层的平整性。当道与道之间的搭接率为30%~40%时,钎焊成形质量较好。在采用逆向扫描策略,扫描道数为10、固定激光功率为700 W、扫描速度为15 mm/s、光斑直径为1.5 mm、搭接率为30%的条件下,实现了多层磨粒的激光逐层钎焊成形,钎料对金刚石浸润包裹充分,钎焊层中间区域平整连续,整体成形质量好。 相似文献
19.
基于脉冲激光加工时的低能量输入和较小的热影响优势,将其应用到金刚石磨粒的钎焊过程中,以实现多层金刚石磨粒的逐层钎焊成形。通过单道及单层脉冲激光钎焊试验,研究了工艺参数对钎焊成形及对金刚石损伤的影响规律,并优选出较好的工艺参数进行了多层钎焊试验。研究结果表明:在脉冲激光钎焊成形过程中,工艺参数的变化主要通过改变峰值功率密度和线能量密度来影响钎焊成形和金刚石损伤形态。输入的能量密度不足时,钎焊道及钎焊层易出现熔融球、金刚石聚集、熔合不充分、不连续及不平整等现象;输入的能量密度过大时,易出现金刚石损伤、粉末材料及金刚石流失逃逸等现象。当线能量密度为14~25 J/mm2、峰值功率密度在5×105~1.5×106 W/cm2时,可得到平整性良好和金刚石磨粒形态良好的钎焊形貌,且在此参数范围内优选的参数条件下实现了多层结构的逐层钎焊成形,得到了较好的表面成形形态及较低的金刚石损伤形态。多层钎焊试块弯曲试验结果表明,钎焊层与基体之间具有较好的结合强度,未出现钎焊层剥离现象。 相似文献