数控机床主轴行星轮变速装置

数控机床主轴行星轮变速装置,能够输出两段转速,当太阳轮、行星轮、行星架和齿轮套相对固定时,各齿轮间的啮合没有相对运动,齿轮无噪声,此时,行星轮变速装置的速比为1:1,满足了机床主轴高速运转的要求,当太阳轮、行星轮、行星架和齿轮套构成了行星轮减速轮系时,通过减速增大了扭矩,满足了机床主轴低速大扭矩输出的要求,该变速装置结构简洁,应用广泛。     

矿用自卸车轮边减速系统可靠性建模分析

矿用自卸车轮边减速系统具有较大的传动比,受制于空间限制,而减小行星齿轮太阳轮齿数,因此会降低齿轮的可靠性。针对于此以某矿用自卸车轮边三级行星减速器为研究对象,根据系统结构和工作原理,基于Romax搭建轮边三级行星减速器虚拟样机有限元模型,对不同工况下各级齿轮的强度和疲劳寿命进行校核,解决传统计算对减速器所受径向载荷、自重及变形等因素考虑不足的问题,分析结果更加精确。结果表明轮边减速系统的齿轮接触疲劳强度、弯曲疲劳安全系数高,使用寿命达到设计标准要求,为同类矿用自卸车轮边减速系统设计研究提供理论依据和分析参考。     

装载机驱动桥轮边减速机构行星轮支承方式的比较分析

装载机驱动桥轮边减速机构主要存在行星轮的跨置和悬臂支承方式,分析了这两种支承方式下的系统变形导致的齿轮啮合错位,利用Romax传动系统设计分析软件,对齿轮副进行了TCA分析,说明了系统变形导致的齿轮载荷分布和强度差异,提出了行星轮跨置支承的优势,在考虑齿轮强度时,除齿轮自身宏观参数之外,还需从系统角度考虑机构变形的影响。     

行星变速皮带轮

我参考了《机械工人》1974年第6期“行星减速皮带轮”,设计了行星变速皮带轮,使用效果良好,现介绍如下: 行星变速皮带轮结构如图所示。在行星减速皮带轮的基础上,输出端又选加两套行星齿枪19和21,分别与太阳轮20和23相啮合。行星齿轮采用标准圆柱齿轮。用键固定在同一行星轮轴上。3个太阳轮用变位齿轮凑中心     

基于MATLAB二级行星轮边减速器可靠性优化设计

电动轮矿用汽车低速大转矩的运行特性需要传动比较大的减速器,因此行星轮式轮边减速系统被广泛应用。针对二级行星轮式减速器结构特点,采用传统设计方法对行星齿轮系统进行可靠度分析,根据已计算的可靠度对齿轮系统进行参数优化。将系统可靠度最大转化为各齿轮的可靠度最大,作为多个目标函数,在实际工况的基础上建立约束条件,利用MATLAB多目标优化函数进行求解,获得最佳的齿轮参数。根据得到的行星齿轮系统的参数,对优化后整套减速系统的可靠性进行分析。分析结果可知,优化设计后,传递效率为0.946,传递比为30.54,满足使用要求;二级太阳轮齿面接触强度可靠性系数为2.52,二级内齿圈齿根弯曲疲劳强度可靠性系数为2.59,二级齿轮可靠度为0.989,可靠性明显提高;主要零件的安全系数等级高;二级减速系统各齿轮的寿命达到设计要求;为同类行星齿轮系统的优化设计提供参考。     

行星轮多级齿轮传动系统耦合特性分析

为研究行星轮多级齿轮传动系统的耦合振动机理,建立了两级定轴齿轮和一级行星轮的行星轮多级齿轮传动系统无量纲动力学方程。对比两级齿轮、行星齿轮传动系统及行星轮多级齿轮传动系统的分岔特性,研究多级齿轮系统的非线性耦合特性。通过研究发现,耦合作用使得一级定轴齿轮突跳点减少,增加了系统的稳定性,但同时又使行星轮的混沌运动传递到定轴,导致二级定轴齿轮出现大范围的混沌运动,从而又降低了系统稳定性。     

多构件浮动重载行星齿轮系统动态均载研究

针对构件浮动对重载行星轮系统行星轮载荷影响问题,以某大型风电行星齿轮系统为研究对象,建立多浮动体行星齿轮系统的有限元分析模型并进行分析。分析当行星架支撑刚度、行星轮误差变化及太阳轮浮动、行星架浮动、以及外载荷变化情况下的行星轮均载变化趋势。结果表明,当系统中采用太阳轮与行星架同时浮动时,系统均载性能最好,在系统误差一定的情况下减小浮动支承件刚度和增大输入载荷能提高行星齿轮系统均载性能,并在均载试验台上对多浮动行星齿轮系统在外载荷及行星架支撑刚度变化时的均载情况进行了试验验证。     

装载机驱动桥行星齿轮架磨损原因及改进措施

<正>1.故障现象某5t轮式装载机在使用过程中出现驱动桥轮边减速器异常发热现象。拆解检查后发现,齿轮传动系统运转良好,磨损量不大,但是轮边减速器的行星齿轮架磨损严重,行星齿轮侧面的垫片已完全陷入行星齿轮架内。齿轮油变质发黑,行星齿轮架磨损情况如图1所示。2.行星齿轮架结构该装载机采用整体式驱动桥,具有2级减速装置。驱动桥中间为采用圆锥齿轮主减速器,主减速器内设有采用圆锥齿轮的差速器。轮边减速器采用直齿行星齿轮减速器。该驱动桥具有结构     

基于模糊理论两级行星轮边减速系统优化设计

行星轮边减速器结构紧凑、承载力大且传动比大,被广泛应用于重型载重车辆。基于两级行星轮边减速系统的结构特点,运用模糊优化相关理论对系统进行优化设计。系统的优化设计为多目标设计,第一级的目标函数为体积最小,第二级的目标函数为可靠度最大。同时根据遗传算法特点,改进权重系数的搜索方法,增大优化搜索空间,与其他优化方法结果相比有一定的提高。在可靠性结果的基础上,将模糊理论应用到田口方法中,对轮边减速系统进行稳健设计,将稳健设计的结果与可靠性优化设计的结果进行对比。根据优化设计的结果,对两级轮边减速系统及其主要部件齿轮、轴承进行仿真模拟分析,结果可知,优化设计后机构轴承寿命、齿轮的强度均达到设计要求,表明优化设计的可行性。     

采煤机滚筒行星减速机构齿轮接触强度分析与改进

针对某型号采煤机滚筒行星减速机构齿轮运行异响严重、寿命偏低的问题,借助ANSYS有限元仿真计算软件,对其开展了接触强度分析.分析结果表明,行星减速结构啮合齿轮接触应力接近材料屈服强度,加剧齿轮磨损是异响严重的主要原因.提高行星减速机构润滑油更换次数之后异响严重问题得到解决,同时降低了滚筒行星减速机构运行声噪,减少了相同时间内行星减速机构齿轮啮合位置的磨损量,延长了行星减速机构的使用寿命.     

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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

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.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

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.