基于油液在线监测的齿轮箱磨损趋势分析与研究

齿轮箱润滑油液中的磨粒携带了大量磨损状态的信息,通过在线监测传感器能监测出油液中磨粒的相关参数(尺寸、数量、生成率等),可判断或推测出齿轮箱的磨损状态。然而,目前在线监测的磨粒相关特征参数与齿轮箱磨损状态的准确对应关系还未得到深入研究。本研究首先采用离线检测的方法验证了在线监测传感器的可靠性,然后通过自主研制的试验台进行了齿轮箱全寿命加速试验,根据不同尺寸磨粒数量、磨粒生成率等的变化趋势对齿轮箱磨损程度做出了预判;最后采用铁谱分析法进一步验证了在线监测齿轮箱故障的准确性。结果表明:基于油液在线监测的磨粒信息(尺寸、数量、生成率)能很好地对齿轮箱磨损状态进行判定和预测。     

反向双激励螺线管在航空发动机油液磨损颗粒检测中的应用

油液磨粒监测有两类：离线与在线监测。为了真正实现航空发动机油液磨粒在线监测，设计了一种反向双激励型螺线管式传感器，实现了航空发动机油液磨粒类型、大小、数量等的实时在线监测。     

单摆冲击法对凿削磨损的动态测量与分析

介绍了单颗粒凿削磨损测试系统的原理、方法以及在镁合金检测中的应用。试验分析了试样划痕形貌和尺寸数据,采集了力学信号数据,以比能耗来对整个单颗粒凿削磨损过程进行动态分析,为研究磨粒磨损机理提供了更多依据。     

磨粒对齿轮箱磨损状态的影响

工程实践中迫切需要探究齿轮箱润滑油中磨屑的变化规律,从而实现对齿轮箱磨损状态的准确评价,进而系统性地揭示齿轮箱的失效机理。采用自主研制的齿轮箱磨损试验机进行摩擦试验探究,采用分散添加不同粒径铁磁性颗粒进入润滑油以及对纯净新油品中铁磁颗粒浓度规律进行跟踪监测的方法,结合对齿轮表面的形貌观测以及油样中的磨损颗粒的铁谱分析和磨损类型判断等技术方法,系统分析了齿轮箱的磨损失效机理。结果表明:磨粒的直径分布导致了不同的齿轮箱磨损失效机理,小尺寸颗粒易造成齿轮箱发生滑动磨损,而大尺寸磨粒主要引起齿轮箱发生疲劳磨损失效;工程应用中,润滑油铁磁颗粒浓度变化曲线的斜率达到tan50°时,齿轮表面发生轻微的点蚀磨损;浓度变化曲线斜率增至tan70°时,齿轮箱齿面已发生严重破坏,应做出预警处理。     

发动机磨损诊断的神经网络技术研究

目的　利用神经网络技术诊断发动机的磨损故障 ,研究神经网络技术应用于机械故障诊断领域的发展方向 .方法　基于油液分析技术 ,对发动机常见磨损故障进行诊断 ,具体包括发动机磨损颗粒的识别、磨损元素浓度值的预测和磨损故障智能诊断专家系统 .结果　对基于油液分析的发动机故障诊断提供了新的方法 .结论　使用神经网络技术可以大大提高发动机磨损故障诊断的效率 ,说明该技术方法在发动机磨损故障诊断领域是有效的 ,同时对其它机械设备的磨损故障诊断具有借鉴意义     

油液污染度与磨损状态的关联性分析研究

通过对机械设备在用润滑油的污染度检测与光、铁谱分析试验，运用灰色系统理论，计算了重量污染度为磨粒浓度以及磨损金属元素（Fe,Cu）之间的灰色关联度。初步揭示了在用润滑油的污染度与光铁谱数据之间的关系，并指出在用油的污染程度可以一定程度上反映机械设备的磨损状态，污染度分析方法可替代直读铁谱分析。     

磨损表面在线自修复研究

磨损是导致机械零部件失效的主要原因,如何在线修复摩擦表面早期出现的磨损,延长机械设备的工作寿命是当前研究的热点.以锌超细粉体作修复剂,利用摩擦磨损试验机对已磨损金属表面进行了在线自修复试验,并对修复表面的形貌、成分、微观硬度等进行了分析测试.结果表明:所制备的修复剂对磨损表面具有明显的修复作用,形成了修复层.由于金属摩擦副的材质和工作条件的不同,对修复剂、在线自修复工艺等也有不同的要求.提出了油润滑下金属摩擦副磨损表面在线自修复的系统设计.     

应用滑油光谱监控技术成功预报的一起航空发动机异常磨损故障

滑油光谱监控技术作为航空发动机视情维修技术的重要组成部分,在飞机发动机的状态监控中发挥着十分重要的作用.本工作围绕故障检查和失效分析,介绍了一起应用滑油光谱监控技术成功预报某航空发动机异常磨损故障的典型案例,认为该技术是当前发动机磨损故障预报和诊断的有效手段,对于保证飞机的飞行安全具有重要意义.     

铁谱技术在工程机械发动机故障预测中的应用

利用铁谱磨粒技术从微观角度对工程机械运行过程监测，能预测、诊断和及时处理发动机非正常磨损早期故障。作者应用铁谱磨粒技术验证和完善了传统磨损理论，并结合实践，分析和证明汽车发动机的故障是可以预测的。     

超音速等离子喷涂12Co-WC涂层在含沙油润滑条件下的摩擦学行为

为探讨含沙油润滑条件下材料的磨损问题,采用超音速等离子喷涂技术在45钢表面制备了12Co-WC涂层.使用T-11球-盘式摩擦磨损试验机考察了涂层在含沙油润滑条件下的摩擦磨损性能.结果表明.超音速等离子喷涂12Co-WC涂层具有致密的组织、高的强度和硬度,在含沙油润滑条件下的摩擦系数略低于灰铸铁,耐磨性比灰铸铁提高4～8倍,同时磨损体积对沙粒尺寸和沙粒含量的变化不敏感.超音速等离子喷涂12Co-WC涂层的失效以磨粒磨损及WC颗粒和喷涂粒子剥落为主.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.