钢球磨煤机齿轮损坏原因及对策

通过对钢球磨煤机衬板、大齿轮的喷淋装置、齿轮罩的分析,找出引起钢球磨煤机大、小齿轮损坏的原因,并提出了相应的预防措施.     

一种基于空气静压支承的自调心装置

介绍了一种基于空气静压支承的自调心装置,可应用于回转对称零件的姿态调整中,可实现被调整姿态零件与装置间的无摩擦运动,保护零件表面质量;该装置采用球面自调心原理实现零件自动对心,采用真空负压实现零件调整后的姿态保持,减少人工调节和检测的反复迭代调整。采用空气静压支承的自调心装置对回转对称零件的姿态进行调整,并针对自调心装置中两个扣合零件的4个舵面分别进行5组实验,实验结果均满足零件轴线垂直度优于0.05 mm的要求;采用自调心装置相对于传统手工调节,其效率由0.5~1 h提高到5 min,效率提升明显。     

小齿轮自调位装置的运动学建模及分析

利用多刚体系统笛卡儿运动学方法对小齿轮自调位装置进行建模。根据铰的性质建立邻接刚体的坐标问的约束方程。约束方程中描述空间刚体姿态的最基本参数为方向余弦阵,基于连体基的基点坐标与方向余弦坐标构成的最基本的笛卡儿坐标,导出一般形式的邻接刚体的基本约束方程。通过建立系统的位置、速度、加速度约束方程求解对系统运动学进行分析。     

圆锥齿轮齿面纵向接触斑点位置及其调整

直齿圆锥齿轮传动中,小齿轮通常是主动齿轮,大齿轮是被动齿轮。齿面接触斑点位置的调整都在小齿轮上进行,因其齿数较少,调整容易。如已有小齿轮,需要在刨齿机上刨削大齿轮时,就只能在大齿轮上进行调整。现述纵向接触及调整方法。     

浅谈高速重载齿轮修形技术

通过分析高速重载齿轮在传动过程中的弹性变形,必须对大、小齿轮齿顶进行修缘或对小齿轮齿顶、齿根进行修正。通过分析在离心力作用下齿轮轮体膨胀的情况,提出必须对齿轮采用基圆直径修正。通过分析大小齿轮温度差以及齿轮轮体不均匀温度分布的情况,提出对齿轮必须进行齿向线性修正。     

接触区域可控的弧齿锥齿轮齿面建模方法

首先建立格里森制螺旋锥齿轮齿面上齿线方向上一个曲线簇的曲线方程,再结合球面渐开线方程,构建表达螺旋锥齿轮齿面的网格状的曲面模型。在此模型的基础上,根据局部共轭原理,对小齿轮进行修齿计算,得到修齿后小齿轮齿面的曲面离散数据,以满足不完全共轭的啮合要求。将数据导入Pro／Engineer建立齿轮模型,并在Pro／Engineer中进行运动仿真对接触区域进行检验。上述方法简化了建模和修齿过程,并能够简便地调整接触点位置。     

介绍一种齿轮减振装置

介绍了一种安装在小齿轮上的减振装置，并对其进行了评述及有关理论分析计算，分析计算证明，它还同时具有提高齿轮抗点蚀承载能力的作用。     

轨道不平顺影响下高速列车齿轮传动系统的振动特性分析

为了分析高速列车齿轮传动系统在轨道不平顺激励影响下的振动特性变化规律,利用动力学软件SIMPACK建立包含齿轮传动系统的整车动力学模型,分别在大、小齿轮内部布置测点,进行无轨道不平顺和有轨道不平顺工况下的动力学仿真实验,获得高速列车时速250 km/h时大、小齿轮的振动加速度。对大、小齿轮横向、纵向和垂向振动加速度幅值进行频域分析,并对比分析了齿轮传动系统在有、无轨道不平顺工况的振动幅值、频谱分布。结果表明,由于轨道不平顺激励的影响,高速列车齿轮传动系统的横向、纵向和垂向振动加强,振动加速度均增幅明显,其中,垂向振动加速度变化幅值最大。齿轮传动系统的振动频率主要集中在0~400 Hz,小齿轮和大齿轮横向振动受轨道不平顺的影响规律一致,但小齿轮受到纵向振动的影响略小于大齿轮,小齿轮受到垂向振动的影响略大于大齿轮。     

摆线齿准双曲面齿轮模拟加工系统建模

简单介绍摆线齿准双曲面齿轮模拟加工系统,以左旋小齿轮模块为例,利用AutoCAD 2006的二次开发工具VBA对摆线齿准双曲面齿轮模拟加工系统三维建模过程进行详细阐述,主要包括齿轮坯实体的构建和铣齿刀盘实体建模.采用摆线齿准双曲面齿轮模拟加工系统中的AKM-852铣齿机加工出10齿左旋小齿轮实体,为摆线齿准双曲面齿轮的优化设计和加工奠定理论基础.     

渐开线齿轮新磨法

采用圆弧蜕变线逼近原理及其砂轮修整装置。可以磨修形齿轮、圆弧齿轮、小齿轮及其他无拐点的任意曲线齿轮,此法还可用于工具制造业中磨原制     

变位非正交面齿轮副小轮齿向修形轮齿接触分析

建立了变位非正交面齿轮的加工坐标系和啮合坐标系,推导了变位小轮及变位非正交面齿轮的齿面方程,计算得到了面齿轮数值齿面,分析了变位对非正交面齿轮齿宽的影响。在变位的基础上研究了对小轮进行齿向鼓形修形,而面齿轮不修形的修形方式。分别对未变位、变位、变位加小轮齿向修形的三种非正交面齿轮传动形式进行考虑安装误差的轮齿接触分析。研究表明：随着变位系数增大,非正交面齿轮最小内半径、最大外半径及极限齿宽均减小;变位不影响非正交面齿轮副的接触规律;小轮齿向修形能降低接触轨迹对安装误差的敏感性,会引起幅值较小的直线型传动误差。     

采用碟形砂轮的斜齿面齿轮磨齿技术研究

为了制造出高精度硬齿面斜齿面齿轮和获得抛物线传动误差并改善啮合性能,对采用碟形砂轮加工双向修形的斜齿面齿轮的磨齿方法进行了研究。设计了渐开线失配的碟形砂轮齿面,分析了碟形砂轮磨削斜齿面齿轮的展成原理,根据展成原理和用渐开线失配的碟形砂轮并改变砂轮的运动,推导出双向修形斜齿面齿轮的齿面方程。给出了双向修形斜齿面齿轮的齿面计算和接触分析实例,结果表明:理论齿面的最大齿面误差为5.98×10-4μm,采用碟形砂轮加工双向修形斜齿面齿轮的磨齿方法是可行的,获得了斜齿面齿轮抛物线传动误差,避免了边缘接触并改善了斜齿面齿轮的啮合性能。     

轴线不平行度对人字齿轮齿面啮合性能的影响分析

人字齿轮传动由于加工安装误差、轴承支撑布置无法对称等条件,不可避免会产生轴线的微量不平行。因人字齿轮齿宽较大、啮合刚度高、标准渐开线齿面线接触等特点,微量的轴线不平行度就会导致严重的齿面偏载,影响齿轮传动的平稳性和可靠性。因此,采用了小轮较大轴向浮动的轴承支撑结构,并研究了小轮轴向浮动的人字齿轮齿面承载接触仿真(LTCA)方法,通过大、小轮轴向固定和小轮轴向浮动两种不同轴承支撑结构的仿真比较,说明小轮轴向自位浮动可以有效改善齿面偏载,为人字齿轮传动系统的设计提供了参考。     

有误差的螺旋锥齿轮传动接触分析

以多体系统误差建模理论和齿轮啮合原理为基础,提出含有机床运动几何误差以及齿轮副安装误差的螺旋锥齿轮齿面接触分析(Error tooth contact analysis, ETCA)方法。以SGM法(大轮展成法加工,小轮变形法加工)加工的弧齿锥齿轮为例,通过ETCA分析,得到机床运动误差和安装误差对螺旋锥齿轮齿面加工质量影响的定量关系,对ETCA和TCA的结果进行对比分析,结果表明机床运动误差和安装误差对螺旋锥齿轮的齿面接触质量有较大的影响,为了通过齿面接触分析达到更准确的反调加工参数的目的,采用ETCA的分析结果指导加工参数反调更为合理。     

The influence of misalignments on mesh performances of hypoid gears

A new method for tooth contact analysis in mismatched hypoid gears is applied for the investigation of the influence of misalignments of the mating members on mesh performances. By using the corresponding computer program, the influence of running offset error, pinion’s axial adjustment error, and angular position errors of the pinion axis on the shape and position of path of contact and of potential contact lines under load, on separations along these contact lines, on angular displacements of the gear member, and on the variation of the angular velocity ratio through a mesh cycle, have been determined. The results obtained have shown that the position errors of the mating members cause edge contact on the tip of the pinion or gear tooth, worsen the conjugation of the contacting tooth surfaces, and considerably increase the angular displacements of the gear member and the angular velocity ratio variation through the whole mesh cycle, that considerably worsens the mesh performances.     

Influence of tooth modifications on tooth contact in face-hobbed spiral bevel gears

In this study the influence of tooth modifications induced by machine tool setting and head-cutter profile variations on tooth contact characteristics in face-hobbed spiral bevel gears is investigated. The concept of face-hobbed spiral bevel gear generation by an imaginary generating crown gear is applied. The modifications of tooth surfaces are introduced into the teeth of both members. The lengthwise crowning of teeth is achieved by applying a slightly bigger radius of lengthwise tooth flank curvature of the crown gear generating the concave side of pinion/gear tooth-surfaces, and by the variation of machine tool settings in the generation of pinion/gear teeth. The ease-off in the tooth height direction of meshing tooth surfaces is achieved by applying a head-cutter whose profile consists of two circular arcs, instead of a straight-line. The method of tooth contact analysis applied determines the path of contact, the potential contact lines, the separations along these lines, and the transmission errors. A computer program implements the method. By using this program the influence of the variation of machine tool settings and of head-cutter geometry on tooth contact is investigated and discussed.     

齿根有油孔时斜齿轮齿根应力仿真分析及实验

利用有限元与实验研究了一种变速器五挡齿轮的小轮根部带有油孔的齿根弯曲应力的问题.利用三维Pro/E和Pro/Mechanica软件,对该变速箱中的五挡齿轮对建立了多齿对同时空间接触的物理力学模型,并进行了每隔2°来分析各个接触瞬间的齿根弯曲应力以及油孔周围应力的分布情况.在一个完整的啮合过程中,得出有油孔齿轮的齿根部第一主应力最大值比无油孔齿轮的齿根部第一主应力最大值增大了13.68％的结论.从齿轮的弯曲疲劳破坏形式与特点来看,仿真结果与实验结果一致.     

Kinematic errors on helical gear of triple circular-arc teeth

Two imaginary skew rack cutter curves with stepped triple circular-arc teeth are presented in this paper. A helical gear pair that includes the gear and pinion surfaces was generated by using two matched imaginary skew rack cutter surfaces. The mathematical models of the helical gear pair with stepped triple circular-arc teeth were developed based on theory of gearing. With the use of these models, the analysis of kinematic errors can be illustrated and evaluated by computer programming and tooth contact analysis (TCA). The assembly errors used had several kinds: ideal assembly errors, vertical misalignment angles, horizontal misalignment angles, manufacturing errors of helical angles, and center distance deviation. TCA revealed that the sensitivity of horizontal misalignment angles was lower than that of manufacturing errors of helix angles but higher than that of vertical misalignment angles.     

Dynamic behavior analysis of spur gears with constant & variable excitations considering sliding friction influence

A new analytical model of a spur gear system with sliding friction is presented. Unlike previous models, the excitation consists of two parts: the rotational driving speed of the pinion and the drag torque acting on the gear. The proposed model was validated with the finite element model. Using numerical method, the steady state resolutions was obtained to mainly demonstrate the nonlinear characteristics under both constant and variable excitations. The results obtained illustrate that sliding friction could introduce additional vibration. Moreover, the sliding friction even could decrease the dynamic transmission errors under proper operation condition. Further, the bifurcation diagram was plotted to show the influence of the rotational driving speed of the pinion on the dynamical characteristic of the gear system. Finally, the fluctuated excitation was used to exhibit their different effects on the gear system, which should form the basis of further analytical and experimental work in the gear dynamic area.