内啮合高阶椭圆斜齿轮副设计方法及实例应用

为促进内啮合高阶椭圆斜齿轮副推广应用,根据最大最小传动比的设计要求,研究内啮合高阶椭圆斜齿轮的实用设计方法,建立了从动轮节曲线数学模型;提供了内啮合齿轮副压力角和重合度校验方法;最后,提供了一内啮合齿轮变速传动机构的设计实例,设计结果表明:所述方法能够正确设计内啮合高阶椭圆斜齿轮副,实现周期性变传动比传动;主动轮压力角及啮合重合度校验合格,齿轮副能够正确啮合。     

四圆弧齿轮的啮合特性

根据四圆弧齿轮基本齿廓,推导出了四圆弧齿轮同一齿上同时啮合的4个啮合点之间的轴向距离。并根据圆弧齿轮齿面接触点的运动规律推导出了多点啮合系数、多对齿啮合系数的计算公式及合理齿宽的选择。制订出了相应的计算表格,为计算四圆弧齿轮的重合度带来了方便。     

直线共轭内啮合齿轮副啮合特性分析

对直线共轭内啮合齿轮副的啮合特性进行了全面分析，包括共轭齿形的求解、啮合过程分析和重合度计算及齿轮参数对重合度的影响等内容。     

直线共轭内啮合齿轮副啮合特性分析

对直线共轭内啮合齿轮副的啮合特性进行了全面分析 ,包括共轭齿形的求解、啮合过程分析和重合度计算及齿轮参数对重合度的影响等内容。     

圆锥齿轮重合度的计算及其曲线

在齿轮传动中,重合度是一个十分重要的指标.重合度的大小对齿轮啮合的平稳性、齿轮传动噪音的大小、齿轮弯曲强度、接触强度及胶合强度的高低都有很大的影响。这些影响是比较复杂的。在各国的齿轮强度计算标准中,对重合度影响的考虑,虽然形式上各有不同,但都一致认为,随着重合度的增加,齿轮的强度都有所提高。本文根据圆锥齿轮的特点,推导关于圓锥齿轮传动重合度的计算公式,并介绍重合度曲线的快速查算方法。什么是齿轮传动的重合度呢?所谓重合度就是齿轮副有效的啮合区域的宽度与齿轮基节     

WN齿轮副多点啮合负载及弯曲强度特征的研究

为了探析WN(Wildhaber-Novikov)齿轮传动的弯曲强度特征及失效原因,提出了基于WN齿轮多点啮合的齿根应力计算原理和方法。针对WN齿轮负载传动的点接触和弹性变形特征,建立了齿根弯曲强度分析模型。根据啮合过程中负载、啮合齿轮副和接触点数的变化进行了齿根弯曲应力的计算,利用有限元方法分析了啮合传动中螺旋角以及中心距误差等对最大齿根应力的影响,揭示了WN齿轮传动的失效原因和弯曲强度特征。通过齿根应力实验测试以及和渐开线齿轮的比较证实了本方法的可靠性。     

齿距误差对弧齿锥齿轮齿间载荷分配和强度的影响

采用齿轮啮合仿真和承载啮合仿真技术，研究了重合度达到2.0的弧齿锥齿轮的齿距误差对啮合性能的影响，针对航空弧齿锥齿轮允许的齿距误差，研究了误差量值对齿轮实际重合度，传动误差、齿间载荷分配和弯曲强度的影响。结果表明，相对齿距误差将降低齿轮的实际重合度，使单齿承受的载荷量增加，边缘接触加剧，弯曲强度不过，在容许范围内的齿距误差将不会严重影响重合度达到2.0的齿轮传动的性能。     

点线啮合齿轮齿根弯曲应力研究

提出点线啮合齿轮齿根弯曲应力计算方法,修正了大齿轮的齿根弯曲应力计算公式,在公未中增加大齿轮弯曲强度提高倍数.通过有限元仿真和试验验证了点线啮合齿轮齿根弯曲应力计算方法,并得出点线啮合齿轮弯曲疲劳强度比渐开线圆柱齿轮至少要提高15%的结论.     

圆锥齿轮重合度的计算及其曲线

<正> 在齿轮传动中,重合度是一个十分重要的指标。重合度的大小对齿轮啮合的平稳性、齿轮传动噪音的大小、齿轮弯曲强度、接触强度及胶合强度的高低都有很大的影响。这些影响是比较复杂的。在各国的齿轮强度计算标准中,对重合度影响的考虑,虽然形式上各有不同,但都一致认为,随着重合度的增加,齿轮的强度都有所提高。本文根据圆锥齿轮的特点,推导关于圆锥齿轮传动重合度的计算公式,并介绍重合度曲线的快速查算方法。什么是齿轮传动的重合度呢?所谓重合度就是齿轮副有效的啮合区域的宽度与齿轮基节     

齿轮弯曲强度有限元精确分析方法研究

通过计算轮齿弹性共轭接触迹,确定齿轮在啮合过程中各个位置的压力角、齿廓接触长度以及接触位置等参数。并对ANSYS进行二次开发,制作了一个精确计算齿轮弯曲强度有限元分析的软件。运用此软件对相同参数的渐开线齿轮与点线啮合齿轮进行弯曲强度的有限元精确计算,得出点线啮合齿轮比渐开线齿轮弯曲强度提高11.7%的结论。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.