曲轴齿轮和曲轴的过盈联接技术研究

以某发动机曲轴齿轮为例,研究齿轮与曲轴之间过盈量的确定方法及影响过盈量的主要因素。通过理论计算确定过盈联接齿轮与轴之间不产生打滑所需的最小过盈量及满足材料屈服极限所需的最大过盈量,并选择合适的配合类型。然后通过理论计算与有限元法相结合来验证有限元模型的有效性。建立参数化的有限元分析模型,分别确定过盈量与各影响因素之间的关系。     

压气机套装叶轮的三维接触非线性有限元分析

增压器压气机叶轮、轴套和轴采用过盈配合技术联成一体，这是典型的三维多体接触问题。本文以某柴油机涡轮增压器的压气机为例，采用有限元参数二次规划法，并结合多重子结构技术分析求解叶轮与轴套、轴套与轴的三维弹塑性有摩擦接触问题，针对不同的过盈量、摩擦系数和转速进行了大量计算，获得了叶轮、轴套与轴之间接触应力的相应分布规律。分析表明：随着叶轮与轴套间过盈量的增大，轴套的外表面与内表面的接触应力是线性增大的，而且内表面的接触应力增加较为迅速，这对于确定合理过盈量和改进设计具有参考意义。     

液氮冷套工艺在内燃机行业中的应用

1前言在内燃机上，有许多部位的装配性质为过盈配合，如气门导管与导管孔、气D'1座圈与座圆孔、气门摇臂与铜套、连杆与铜套和凸轮轴、机油泵、水泵上的轴承与轴承孔，等等．这些配合副中过盈量的存在给内燃机制造和维修的装配过程带来了许多麻烦．液氮冷套工艺在内燃机制造和维修行业中的应用，较好地解决了常规装配作业中存在的诸多问题，是一种实用有效的方法．2常现装配法2．1压装法图1为压装法的示意图．工件（1）与工件（2）为过盈配合关系．为了把工件（l）按设计要求装配到工件（2）中，需要专用工具导引和扶正，并施加适当的外力…     

连杆小头衬套过盈装配失效机理的分析及解决方法

连杆小头衬套过盈装配失效机理的分析及解决方法夏尚能，王昌一（海军工程学院）１概述一般柴油机连杆衬套以内径磨损量为更换依据，轻１２Ｖ１８０、轻４２－１６０、１２Ｖ１５０等轻型强载机往往因过盈量锐减而报废，所以分析过盈量随使用期增长而减小的机理是解决问题...     

粉末冶金齿轮与齿轴过盈配合分析

通过对粉末冶金齿轮与齿轴过盈配合的分析,合理选择了齿轮和齿轴的过盈量及粉末冶金齿轮的强度,既保证了传递一定扭矩,又防止了粉末冶金齿轮运转中脆裂失效。     

汽轮机套装叶轮接触问题的三维有限元分析

运用有限元分析软件SAMCEF,对某型号汽轮机套装叶轮与轴的过盈配合问题作三维模型计算分析,计算中采用接触单元处理过盈配合边界,得到了转子位移和应力分布,并对原来的过盈量设计进行了优化改进,在保证安全性的前提下减小了轮盘的接触应力。     

基于反向传播神经网络的增压器涡轮转子过盈连接结构优化设计

针对钛铝合金涡轮与K418合金套的过盈连接结构存在的应力问题，以涡轮转子过盈连接结构为研究对象，设计型线结构并建立过盈连接结构应力预测模型，基于过盈连接结构应力预测模型分析不同型线对应力分布状态的影响。研究结果表明：过盈连接结构应力预测模型具有较高的精度，对平均接触应力的预测误差为0.67%，对最大Mises应力的预测误差为8.25%。采用过盈连接结构应力预测模型得到的型线优化设计方案使涡轮轴最大Mises应力减少了42.01%，而平均接触应力只减少了10.22%，增压器涡轮转子过盈连接结构可靠性显著提高。     

大功率柴油机曲轴飞轮圆锥过盈联结设计方法

针对某型柴油机螺栓端面压紧联结方式在发动机功率进一步强化时发生了部分螺栓松脱、甚至螺栓和定位销被剪断的情况,对该联结方式做了改进,将原先的端面压紧联结改为圆锥过盈联结。通过经典弹性力学方法计算出合理的过盈量以保证联结的可靠性;同时采用有限元仿真软件ABAQUS得到了连接面接触应力的分布情况,验证了过盈量的合理性;分析了危险区域的应力集中现象,提出了降低应力集中的优化方案。     

发动机碗形塞结构对密封压力的影响研究

针对碗形塞密封泄漏问题,设计压装试验,与有限元计算相互验证;基于ANSYS工具,在二维模型的基础上,通过仿真计算具体探明并详细分析了碗形塞锥面过盈密封的密封质量与碗形塞结构参数的关系。结果表明：密封面最大压力随碗形塞半径增大而减小,随厚度增大而增大;基于不同过盈量,碗形塞锥面过盈密封可分为上边缘线密封、面密封、下边缘密封3种密封状态;对于D75碗形塞,锥度为1∶20时的最优过盈量区间为0.10～0.14 mm;锥度越大,最优过盈量区间越大。在此基础上,将各规格碗形塞改为锥度1∶10,优化了过盈区间及密封压力,并提出了一种可以增大密封压力和改善压力分布的弧面密封形式。     

某低速柴油机曲轴齿轮过盈装配分析

根据某低速柴油机曲轴齿轮装配的实际工况,建立齿轮及过盈轴的三维有限元模型,对曲轴齿轮过盈装配进行分析。研究了不同装配过盈量下齿轮的应力分布情况,得出齿轮装配过盈量对齿轮受力影响的规律;并通过与增加凹槽模型的计算结果的对比,得到改善齿轮应力分布的方法。     

Design of packing cup interference fit value of hypercompressors for low density polyethylene production

The hypercompressor is one of the core facilities in low density polyethylene production, with a discharge pressure of approximately 300 MPa. A packing cup is the basic unit of cylinder packing, assembled by the interference fit between an inner cup and an outer cup. Because the shrink-fitting prestresses the packing cup, serious design is needed to gain a favorable stress state, for example, a tri-axial compressive stress state. The traditional method of designing the interference fit value for packing cups depends on the shrink-fit theory for thick-walled cylinder subject to internal and external pressure. According to the traditional method, critical points are at the inner radii of the inner and external cup. In this study, the finite element method (FEM) has been implemented to determine a more accurate stress level of packing cups. Different critical points have been found at the edge of lapped sealing surfaces between two adjacent packing cups. The maximum Von Mises equivalent stress in a packing cup increases after a decline with the rise of the interference fit value. The maximum equivalent stress initially occurs at the bore of the inner cup, then at the edge of lapped mating surfaces, and finally at the bore of the outer cup, as the interference radius increases. The traditional method neglects the influence of axial preloading on the interference mating pressure. As a result, it predicts a lower equivalent stress at the bore of the external cup. A higher interference fit value accepted by the traditional method may not be feasible as it might already make packing cups yield at the edge of mating surfaces or the bore of the external cup. Along with fatigue analysis, the feasible range of interference fit value has been modified by utilizing FEM. The modified range tends to be narrower and safer than the one derived from the traditional method, after getting rid of shrink-fit values that could result in yielding in a real packing cup.     

Elastoplastic frictional contact problem study on interference fits of compressor

The FE parametric quadratic programming (PQP) method developed from the parametric variational principle (PVP) was used for the analysis of the stress distribution of the 3D elastoplastic frictional contact of an impeller-shaft sleeve-shaft. A locomotive-type turbocharger compressor with 24 blades under combined centrifugal and interference-fit loading was considered in the numerical analysis. The solution of elastoplastic frictional contact problems belongs to unspecified boundary problems where the interaction between two kinds of nonlinearities should occur. To save time in the numerical computation, a multi-substructure technique was adopted in the structural modeling. The effect of fit tolerance, wall thickness of the shaft sleeve, and rotational speed on the contact stress was discussed in detail in the numerical computation. To decrease the difficulty of the assembly process and ensure the safety of the working state, the amount of interference between the shaft sleeve and shaft by press-fitting should be controlled strictly to avoid the rapid increase of contact stress. The numerical results show that the algorithm has high accuracy and good convergence. The study can be referred to in deciding the proper fit tolerance and improving the design and manufacturing technology of compressor impellers. __________ Translated from Engineering Mechanics, 2007, 24(1): 186–192, 177 [译自: 工程力学]     

Quenching residual stresses in 7060 aluminium alloy gas cylinder necks

A destructive technique under development to determine residual stresses in thick-walled pressure vessels has been employed to determine quenching residual stresses in 7060 aluminium alloy gas cylinder necks. The gas cylinders were supplied with interference fit collars attached to the apex of the gas cylinder neck. The effect the elastic interference fit stresses have on the quenching residual stresses in the gas cylinder neck was also investigated. Maximum tensile circumferential quenching residual stresses were detected in the gas cylinder neck below the threaded region of the bore. The magnitude of the maximum tensile circumferential quenching residual stress was in the order of half the yield strength of the aluminium alloy. The interference fit stresses only altered the quenching residual stresses in the immediate vicinity of the threaded bore. It was concluded that the interference fit collar provided no significant effect on the magnitude of the maximum tensile circumferential quenching residual stress in the gas cylinder neck.     

1100MW核电发电机转子长、短护环结构计算及比较分析

1 100 MW核电发电机是未来几年发展的主力机型,转子作为发电机中最关键的零部件,其运行时承受巨大的离心应力(本身旋转)和短路力矩(来自于电网)的作用,直接影响到发电机的安全运行;护环是汽轮发电机转子中承受应力最大的一个部件,为确保护环在运行中安全可靠,有必要对其在各种状态下的应力进行分析。主要通过ANSYS对1 100 MW级核电汽轮发电机的护环装配进行机械计算,对长搭接护环、短搭接护环进行计算和比较分析,并选取合适的过盈量以使得护环装配体中的各部件能满足设计要求,根据分析结果优化选择护环设计结构。     

Finite element analysis of tooth load distribution on P-110S conic threaded connections

Based on elastic mechanics and by use of thick cylinder theory, this paper presents a finite element analysis model with interference fit and axial load on P-110S conic threaded connections and the tooth load distributions on contact threaded surfaces were investigated. A 2D finite element model with elastic-plastic axisymmetric contact threaded surfaces was established and the tooth load distributions on its thread teeth were analyzed under different interference fit and axial load. Results for the loads on every engaged tooth are obtained. These indicate that the load distribution on the engaged teeth is not uniform, with the maximum tooth load concentrated on the first three pairs or the farthest two pairs of engaged teeth from the pin end and the middle teeth only bear a very small load. Such results are identical to the practical situation and indicate that the finite element model proposed in this paper is reasonable.     

Analysis of the stresses and displacements for a composites interference fit multi-rim flywheel

储能飞轮由轮毂和多环复合材料轮缘组成,飞轮旋转时轮毂和轮缘既受到离心力作用,同时又受到内外界面压力的作用,且不同转速下界面压力不断变化,使得分析计算由静止到最大工作转速的不同工况,以及飞轮上不同径向位置的应力非常复杂。本工作在平面应力下分别推导了各向异性材料轮缘在离心力作用下和受内外压力作用下的应力和位移解析式,进而采用叠加原理可计算飞轮在不同转速工况、径向不同位置的应力和位移,简化了应力和位移求解过程,可用于飞轮环间过盈量的确定、强度校核和极限转速计算等设计与分析。应用这种方法对一个实际飞轮进行了分析,并绘制了应力和位移曲线。