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为了测试自主研发的双离合自动变速器齿轮敲击现象,在变速器(Noise Vibration Harshness,NVH)试验台架上进行了齿轮敲击试验,获得了敲击出现的输入轴角加速度阈值.根据齿轮敲击相关理论,选用角加速度均方根比作为敲击评价指标,制定了台架齿轮敲击试验工况,利用低惯量电机模拟扭矩波动,转速传感器采集从动齿轮转速,数据采集设备采集传感器信号并进行后处理.试验结果表明,在该试验工况下变速器各试验挡位均出现敲击现象;双离合变速器非工作轴的齿轮对整体敲击噪声贡献量较小;相同挡位时,输入转速越高,齿轮敲击的门槛越高.最终统计出各挡位在不同转速下出现敲击的阈值,为变速器敲击噪声控制提供了参考. 相似文献
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变速器作为原动件和执行件之间的传动装置,广泛应用于工矿企业,建筑,机械等行业中。对于变速器的参数化设计以及结构、可靠性优化已经比较成熟,而对于变速器箱体的优化比较少。本文针对新型电液换挡定轴式变速器的结构,在传动路线确定的条件下,将齿轮啮合的情况用平面拓扑结构表示;以箱体端面面积最小为目标函数建立数学模型,并根据几何约束关系将原有的多个设计变量简化为2个设计变量;对模型进行求解,得到传动轴的最优布局方案。优化后的端面面积较初始面积有所减少,因此简化后的模型针对箱体端面最优化问题是可行的,且使得求解过程可视化。 相似文献
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《机械设计》2019,(11)
为了解决搜索3自由度以上车辆自动变速器行星齿轮机构方案数量巨大,优选计算时间长的问题,提出对编码矩阵的结构方案进行有效地筛选和优化的方法。对行星齿轮机构各构件按特定规则进行编码,组合遍历综合出行星排矩阵,剔除同构方案,再组合遍历综合出换挡操纵元件矩阵,建立行星齿轮机构的结构矩阵。根据行星齿轮机构的一般运动学方程得到理论传动比表达式。根据相邻挡位间满足"单一换挡原则",通过图的深度优先遍历搜索得到换挡逻辑序列。将目标传动比与实际传动比的相对误差平方和作为非线性最小二乘法的目标函数,通过优选算法确定行星齿轮机构的基本属性。基于MATLAB对实例方案进行优选计算,得到2组最优的换挡方案。结果表明,该方法对多自由度行星齿轮机构方案优选具有可行性和有效性。 相似文献
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手动变速器的噪声控制是汽车噪声控制的难点之一.基于低噪声变速器测试台,对某5档手动变速器的噪声特性进行了全面测试.综合利用频谱分析、阶次分析和相干分析等方法来识别变速器的主要噪声源.分析表明:变速器的振动主要是由挡位齿轮啮合过程以及主减速齿轮啮合过程共同引起;且高速时挡位齿轮啮合过程引发强烈振动的原因与齿轮轴弯曲和齿轮模态有关;5档高速工况时,变速器噪声的主要引发原因是变速器箱体表面某位置的振动,若要改善变速器的振动噪声特性,可从该位置处人手.分析结果为低噪声变速器的优化设计提供了试验支持. 相似文献
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汽车环面型无级变速器结构参数优化设计 总被引:3,自引:0,他引:3
在分析环面型无级变速器(Continuously variable transmission,CVT)的速比变化、接触参数基础上,提出以考虑环面半径最小和在整个传动比范围内平均传动效率最大为追求目标的多目标优化设计,并以膜厚比、接触强度以及不干涉等为约束条件,建立环面无级变速器结构参数优化设计数学模型.求解时,以多目标优化法中的乘除法建立评价函数,用Matlab软件中基于二次序列规划(Sequential quadratic programming,SQP)优化算法的Fmincon函数对优化数学模型进行求解.分析实例表明,优化后环面半径、环腔半径减小,CVT体积更小,结构更紧凑,传动效率明显提高.该优化设计方法能够有效提高环面型无级变速器的综合性能. 相似文献
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为了在动力性满足目标的前提下进一步提升经济性,建立了Cruise和Isight的联合仿真模型,应用多岛遗传优化方法,在确定的动力性和结构设计约束条件下对变速器的各挡位速比参数进行优化,得出满足性能指标要求的基础优化方案。依据驾驶平顺性和齿轮结构的要求对基础优化方案从工程化的角度进行调整,最终得出满足动力性和工程化要求的工程化可行方案。工程化后的最终方案动力性刚好满足目标要求,NEDC(New European Driving Cycle)循环工况综合油耗比原方案降低0.26 L/100km,经济性改善了3.86%,并且等转速换挡的平顺性较原始方案有所改善。 相似文献
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Gearbox Deterioration Detection under Steady State, Variable Load, and Variable Speed Conditions 总被引:1,自引:0,他引:1
SHAO Yimin CHRIS K Mechefske OU Jiafu HU Yumei 《机械工程学报(英文版)》2009,22(2):256-264
Multiple dominant gear meshing frequencies are present in the vibration signals collected from gearboxes and the conventional spiky features that represent initial gear fault conditions are usually difficult to detect. In order to solve this problem, we propose a new gearbox deterioration detection technique based on autoregressive modeling and hypothesis testing in this paper. A stationary autoregressive model was built by using a normal vibration signal from each shaft. The established autoregressive model was then applied to process fault signals from each shaft of a two-stage gearbox. What this paper investigated is a combined technique which unites a time-varying autoregressive model and a two sample Kolmogorov-Smirnov goodness-of-fit test, to detect the deterioration of gearing system with simultaneously variable shaft speed and variable load. The time-varying autoregressive model residuals representing both healthy and faulty gear conditions were compared with the original healthy time-synchronons average signals. Compared with the traditional kurtosis statistic, this technique for gearbox deterioration detection has shown significant advantages in highlighting the presence of incipient gear fault in all different speed shafts involved in the meshing motion under variable conditions. 相似文献
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以一台单级直齿齿轮箱为研究对象,设计了适配的整体式挤压油膜阻尼器(integral squeeze film damper,简称ISFD)结构,对ISFD在齿轮箱中的应用进行了研究。分别测量了在不同载荷和转速工况下,齿轮箱安装传统刚性支承和ISFD弹性阻尼支承后的箱体振动。研究结果表明,ISFD弹性阻尼支承可以有效降低不同转速下齿轮箱的冲击振动,改善齿轮箱的动力学性能,保证齿轮系统稳定运行。不同载荷工况下的实验数据表明:ISFD支承对不同负荷的齿轮箱有较好的减振性能;对齿轮箱的啮合频率及其倍频等高频振动成分,ISFD也有较好的抑制效果。该研究结果可为ISFD在齿轮箱中的实际工程应用提供参考。 相似文献
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飞溅润滑时,二级传动齿轮箱内部润滑油流场分布情况十分复杂,传统有限元方法难以对其进行可视化仿真分析,在模型处理、算法选用、网格划分和计算工作量等方面存在诸多问题。基于充分的调研与大量的前期计算分析,利用移动粒子半隐式(MPS)法对轨道车辆用二级传动齿轮箱的飞溅润滑特性进行研究。分析了不同输入轴转速、初始润滑油油量和环境温度下齿轮箱内部润滑油的流场特性,实现了齿轮箱飞溅润滑的可视化计算;分析了不同工况下齿轮啮合点的油液粒子数时域变化情况,发现啮合处粒子数与转速关系不大,与初始油量成正相关,40 ℃时啮合处滑油粒子数最多,润滑效果最好;分析了各工况的齿轮箱搅油功率损失情况,发现搅油功率损失与输入轴转速和初始滑油油量成正相关,与环境温度的提高成负相关,且均为非线性变化。 相似文献
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基于自组织映射的齿轮箱状态监测可视化研究 总被引:2,自引:0,他引:2
提出了一种自组织映射网络训练结果的可视化方法——距离映射法,该方法通过计算出竞争层神经元权矢量与输入模式的相似度,并综合考虑神经元的网格分布,把输入矢量降维映射到二维平面。结合该方法研究了自组织映射网络在齿轮箱故障识别和状态监测中的应用。与U-矩阵法相比,该方法能更加清楚地将齿轮正常、裂纹和断齿状态的特征数据映射到二维平面的不同区域,将齿轮箱状态聚类分开,特征数据在平面上的映像点轨迹变化趋势直观反映了齿轮箱工作状态的变化,便于及时监测识别出齿轮的早期故障及其变化趋势。 相似文献
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David E. P. Gonalves Carlos M. C. G. Fernandes Ramiro C. Martins Jorge H. O. Seabra 《Lubrication Science》2013,25(4):297-311
In this study, four different fully formulated ISO VG 320 wind turbine gear oils were select: a mineral oil‐based, a polyalphaolefin‐based, an ester‐based and a polyalkyleneglycol‐based fluids. Their physical properties (viscosity, thermoviscosity, piezoviscosity etc.) were characterised for a wide range of operating temperatures. A two‐stage multiplying gearbox, with helical gears, was selected to evaluate the influence of the wind turbine gear oil formulation on torque loss with the gearbox operating at low speed (130–230 rpm) and high torque (500–1000 Nm). The results obtained showed that each wind turbine gear oil formulation generated very different torque losses, evacuated heat flows and operating temperatures, with differences above 20 °C under the most severe operating conditions. A numerical model was developed, simulating all power loss mechanisms inside the gearbox, in particular the churning and friction losses. The coefficients of friction, between gear teeth and between rolling elements and bearing raceways, were calculated for all the tested oils. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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为监测某风场5台风机的齿轮箱润滑油的运行状态,对影响齿轮油衰变和齿轮箱寿命的指标,如齿轮油黏度、黏温性能、水分、酸值和污染物等进行监测,分析在用润滑油在不同运行时间下各个指标的变化情况。结果表明:在不同运行时间下各齿轮油的运动黏度有一定变化,但未发生明显衰变,对齿轮箱不会产生较大影响;酸值和水分的测试结果也显示齿轮油尚未发生明显的劣化;在不同运行时间下齿轮油的动力黏度变化不大,表明齿轮油并未受到严重的剪切作用,其结构没有发生明显的变化;温度对齿轮油有重要的影响,随着温度的降低,齿轮油的动力黏度逐渐变差,因此,齿轮箱的运行应控制在合适温度范围内。污染度测试结果表明,齿轮油的污染度已超标,最高达到22/20/17,最低为18/16/11,可采用更换过滤器或者安装旁路过滤系统的方式来控制该风场风机齿轮箱润滑油的污染度,以延长齿轮箱的使用寿命。 相似文献
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提出了一种应用叠加原理计算齿轮箱整体变形的方法,包括箱体、轴承、传动轴和齿轮的变形。重点阐述了利用ANSYS刚体耦合功能生成齿轮箱体柔度矩阵,建立柔度矩阵、载荷向量、变形向量三者关系方程,从而计算箱体变形的方法。以风力发电增速器齿轮箱为例,分析齿轮箱整体变形对支点反力和齿面接触应力及齿根弯曲应力的影响。 相似文献
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During the condition monitoring of a planetary gearbox, features are extracted from raw data for a fault diagnosis.However, different features have different sensitivity for identifying different fault types, and thus, the selection of a sensitive feature subset from an entire feature set and retaining as much of the class discriminatory information as possible has a directly effect on the accuracy of the classification results. In this paper, an improved hybrid feature selection technique(IHFST) that combines a distance evaluation technique(DET), Pearson's correlation analysis, and an ad hoc technique is proposed. In IHFST, a temporary feature subset without irrelevant features is first selected according to the distance evaluation criterion of DET, and the Pearson's correlation analysis and ad hoc technique are then employed to find and remove redundant features in the temporary feature subset, respectively, and hence,a sensitive feature subset without irrelevant or redundant features is selected from the entire feature set. Further, the k-means clustering method is applied to classify the different kinds of health conditions. The effectiveness of the proposed method was validated through several experiments carried out on a planetary gearbox with incipient cracks seeded in the tooth root of the sun gear, planet gear, and ring gear. The results show that the proposed method can successfully distinguish the different health conditions of a planetary gearbox, and achieves a better classification performance than other methods. This study proposes a sensitive feature subset selection method that achieves an obvious improvement in terms of the accuracy of the fault classification. 相似文献