传递较大功率的轴毂过盈配合一些问题的探讨

在食品、金属加工、冶金、机械等工业中 ,常常见到用较大直径和长度的轴毂过盈配合来传递动力 ,这种过盈配合传递功率大 ,轴毂受到较大力偶矩的作用 ,即所谓慢速重载荷。轴毂传递动力是通过轴毂配合表面的摩擦力来实现的 ,这就要求轴毂要有合适的过盈量 ,如果没有考虑轴毂配合的各种影响因素和慢速重载荷的特点 ,仅简单套用公式确定过盈量 ,就会因过盈量太小而产生“滑毂”(毂径向滑动 )现象 ,如果随意加大过盈量 ,会导致毂的断裂。过盈量的计算通常采用下列公式δｍｉｎ=Ｐｍｉｎｄ(Ｃ1Ｅ1+ Ｃ2Ｅ2)× 10 (1)Ｐｍｉｎ=2Ｔｆπｄ2 ｌ=2× 9.…     

转子测绘中过盈配合对密封间隙的影响

介绍了转子零部件间的过盈配合对密封间隙的影响,通过分析指出如何避免此问题,保证测绘的准确性。     

热装轮轴组件时冷缩轴向间隙的消除

热装拆适用于配合过盈量较大的轮轴组件连接 ,而消除齿轮与轴肩的端面冷缩轴向间隙 ,又可提高机械传动系统的精度和刚度。控制好热装拆的各项技术参数是极为重要的。本文所述是通过数年的生产实践 ,总结出来的工艺方法。生产国家新产品———ＧＣＹ型钢轨探伤车的轮轴传动系统 ,是应用这项技术的成功实例。　　一、消除冷缩轴向间隙　　由于金属材料的热胀冷缩作用 ,热装后的轮轴组件完全冷却后 ,齿轮端部与轴肩贴合处将出现不同程度的间隙。这不仅改变了齿轮的轴向位置 ,而且传动系统的刚度也受影响 ,对精度要求较高的机械传动系统 ,视其为…     

齿轮与轴压装过程过盈配合研究

过盈配合由于连接承载能力强、结构简单等特点,被广泛应用于实际生产中。由于齿轮与轴之间装配过盈量直接影响着齿轮传动的工作性能,因而对齿轮与轴过盈配合研究具有重要的意义。从理论上详细地推导了齿轮和轴过盈配合过程,建立了过盈量计算公式,并采用有限元法对齿轮与轴之间的最大过盈量进行了数值计算,得到了应力分布和压装力变化,接触应力结果表明理论计算和有限元计算结果基本一致,可为齿轮与轴过盈设计提供一定的理论和依据,具有重要的实用价值。     

轴与孔紧配合连接采用复合装配工艺的分析

复合装配工艺是指轴与孔的装配，除了应用公差配合原理使两者紧密结合外，辅以胶粘剂以提高装配工艺性的一种方法，复合装配工艺可使轴与孔的接合力明显优于纯压紧配合的接头，轴与孔接合面上的应力分布与加工面的表面粗糙度及孔的变形能力有关。     

大型泵用齿轮箱输出轴过盈设计与数值分析

针对某核电站冷却水泵输出轴的过盈结构的设计计算,分别按"极限与过盈配合国标"标准公式和数值方法进行了计算与校核,得出了最大与最小过盈量的接触压力,对传递转矩的可靠性与材料的可靠性进行了评估,完成了过盈装配所需最小温度的计算,为水泵的安全可靠运行提供保障。     

轴承内圈与轴的配合过盈量分析

推导了反映轴承内圈与轴配合尺寸与两者相互作用力之间关系以及两者配合后内圈滚道胀大量的理论公式,基于这些公式可以对内圈和轴过盈配合后过盈量的优化、内圈滚道胀大量的计算及轴承和轴的性能进行分析.     

定位优先级约束下间隙配合的变动解析与装配成功率计算

装配特征之间的变动解析是产品装配偏差累积分析的重要基础,针对现有研究成果未考虑零件间装配特征定位顺序对配合间隙影响的问题,提出一种定位优先级约束下间隙配合的变动解析模型与装配成功率计算方法。建立了两个零件之间多基准装配的数学模型,并分析装配特征在配合前相对于装配名义位置的变动。通过对平行平面配合、圆柱面配合、圆锥面配合以及球面配合等四类间隙配合的接触状态进行分析,得到装配基准特征与装配目标特征在配合后相对装配名义位置变动所需满足的约束条件。在此基础上提出定位优先级约束下的装配特征之间的配合变动算法,并给出包含多组装配特征配合的两零件之间的装配成功率的计算方法。以一种测量仪器结构的装配为实例,验证了上述方法的可行性。     

差速器总成轴向游隙专用检具的设计

通过介绍差速器总成轴向游隙专用检具的设计结构、工作原理以及检测方法,以期实现差速器总成左右转向齿轮的轴向游隙快速、准确测量。     

Influence of tip clearance on pressure fluctuations in an axial flow pump

Rotor-stator interaction in axial pumps can produce pressure fluctuations and further vibrations even damage to the pump system in some extreme case. In this paper, the influence of tip clearance on pressure fluctuations in an axial flow water pump has been investigated by numerical method. Three-dimensional unsteady flow in the axial flow water pump has been simulated with different tip clearances between the impeller blade tip and the casing wall. In addition to monitoring pressure fluctuations at some typical points, a new method based on pressure statistics was proposed to determine pressure fluctuations at all grid nodes inside the whole pump. The comparison shows that the existence of impeller tip clearance magnifies the pressure fluctuations in the impeller region, from the hub to shroud. However, the effect on pressure fluctuation in the diffuser region is not evident. Furthermore, the tip clearance vortex has also been examined under different tip clearances.     

Dynamic analysis of cross shaft type universal joint with clearance

Cross shaft type universal joint is widely used in ground vehicles to transfer torque between two intersecting axes, and its transmission feature can make a great contribution to NVH performance of the vehicle. We looked at the assembling clearance at cross shaft neck, and presented a dynamic model of cross shaft type universal joint with clearance at cross shaft neck. Two-state model is applied to describe the contact force between the cross shaft and driving joint fork based on Hertz theorem, and lumped mass method is applied to build up the dynamic model of the universal joint. Based on this model, numerical analysis is carried out to discuss the transmission feature of the universal joint with clearance at cross shaft neck, and the influence of clearance on the dynamic behavior of the system is evaluated with numerical results based on time history, power spectrum, and phase portrait. The method and conclusions presented are helpful to improvement of the transmission feature of cross shaft type universal joint.     

基于CBLRE模型的轴向柱塞泵空化状态检测研究

空化现象的产生严重制约了轴向柱塞泵向高速高压方向发展，需要对柱塞泵的空化状态检测与智能故障诊断展开研究，因此，结合深度学习网络与非线性分类器的优点，提出了一种基于CBLRE(CNN+BiLSTM+RELM)模型的柱塞泵空化状态识别方法(检测模型)。首先，对不同空化状态下柱塞泵的一维原始振动信号进行了数据增强，并对其进行了标准化处理；然后，利用卷积神经网络(CNN)自动提取信号的特征，并对其进行了特征降维处理；利用双向长短期记忆(Bi-LSTM)网络学习特征序列的时间依赖性，利用正则化极限学习机(RELM)的非线性分类器对特征进行了分类，实现了对柱塞泵的空化状态检测与智能故障诊断；最后，为测试CBLRE模型的性能，搭建了实验平台，在此之上将CBLRE模型与其他模型进行了对比，分析了该模型在不同工况下的性能表现。研究结果表明：该模型的结构稳定、训练时间短，且在不同负载下均可保持良好的泛化性能，空化状态识别率均达到99%以上，该结果验证了柱塞泵空化状态识别方法的有效性；此外，该模型还可有效识别空化现象与柱塞泵的其他故障。     

汽车后桥半轴的疲劳寿命预测分析

为了提高汽车后桥半轴疲劳寿命检验的效率以及检测的安全性,基于虚拟现实技术提出了一种台架试验与仿真相结合的复合分析检验方法.在一定量台架试验基础上,利用Pro/E参数化设计方法,对汽车后桥半轴进行三维实体建模,ANSYS WorKbench有限元疲劳分析模块对后桥半轴进行疲劳寿命预测分析,获得的结果与一定量台架检验的结果对比分析,得出预测结果与试验结果一致,验证了方法的正确性.这种复合的检验方法相对于单-的台架检验方法,减少了产品的试验样品数量,缩短了开发周期,提高了安全性,降低了开发成本,同时也为农用、工程车辆传动系冲击性能的研究提供了参考.     

Dynamic stability of a rotor with shear-flexible shaft under axial loads

The dynamic stability of shear-flexible rotating shaft with a disk under axial forces has been studied by employing the transfer matrix method. The conventional transfer matrix was modified to include both the applied axial force and the shear deformation. The shear effect is considered based on Engesser’s and Haringx’s buckling theories for shear-flexible beam. A computer program was developed to investigate the influence of both the axial force and the shear deformation on the stability and the natural frequencies of general rotor systems. Two rotor system models are considered: the overhung rotor with or without an intermediate support and the simply supported Jeffcott rotor. The effect of shear deformation and the difference between the Engesser and Haringx approaches increase with an intermediate support for an overhung rotor.     

光学舱装配中轴向间隙测量的改进

传统的轴向间隙的测量采用塞尺,存在一定的弊端,采用新的在被测部件上施加一定的拉力,同时用百分表测量轴向间隙的办法,可克服传统测量轴向间隙的弊端,而且准确、具体.     

利用载荷谱的轮式装载机半轴有限元分析

建立了包含花键齿、退刀槽及其曲线式倒角的某轮式装载机半轴实体几何模型,通过布尔运算将半轴几何体切分为多个子几何体,根据各个部分的应力、应变特点定制出多个网格划分方案,控制网格的质量与数量,采用最少的节点约束在不影响分析结果的前提下消除刚体位移,基于实际测试得到的传动系载荷谱确定了最大转矩载荷,经有限元计算得到后续疲劳分析需要的应力与外载荷的准确映射关系。     

Dynamic modeling and analysis of axial vibration of a coupled propeller and shaft system

The dynamic and acoustic characteristics of a coupled propeller and shaft system which is modeled by the transfer matrix method are studied. The elasticity of the propeller is taken into consideration by employing the equivalent reduced modeling method. Thus the influence of the elastic propeller on the vibro-acoustic responses of the coupled system is investigated. To reduce the axial vibration of the coupled propeller-shaft system, the influence and location of the vibration isolator on the structural and acoustic responses is presented. Simulation results demonstrate that utilizing the relationship between the natural frequency of the propeller and the resonance frequency range of the shaft can control the vibration of the coupled system without other vibration control method. Utilizing a vibration isolator is another effective way to control vibration. The optimal position for the isolator installed between the shaft and the thrust bearing is investigated.     

平地机车桥螺栓预装工艺设计与提升

具体分析了车桥螺栓压装过程中存在的各种问题及技术难点,依据各种过盈配合装配方法的特性以及零部件结构与性能要求,选择确定合理的工艺方案并进行具体工艺装备的选型设计;且在液压机全自动化操作规范的基础上,提出几点工艺改善建议,从而实现车桥螺栓预装质量与效率的提升。