共查询到19条相似文献,搜索用时 125 毫秒
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小倾角船用齿轮箱由于输入轴与输出轴存在一个夹角,使螺旋桨获得一个入水角,可广泛应用于高速快艇和游艇上,开展小倾角船用齿轮箱系统动态特性研究具有重要的意义。论文以某小倾角船用齿轮箱为研究对象,通过支撑轴承把传动子系统和结构子系统耦合起来,建立齿轮-轴-轴承-箱体耦合系统三维有限元动力学分析模型。用Lanczos方法对系统固有特性进行了分析,获得该小倾角船用齿轮箱固有频率和振型。用锤击法对该小倾角船用齿轮箱固有特性进行了试验模态分析,验证了理论分析的正确性,为小倾角船用齿轮箱的动态性能和优化改进奠定基础。 相似文献
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针对目前国内外各种指示扭矩估计方法的优势与不足,基于柴油机非线性动力学模型,提出通过瞬时转速估计指示扭矩的方法。文中引入当量角加速度概念,消除了柴油机的动力学模型非线性项影响。将当量角加速度视为柴油机系统输入,指示扭矩视为输出,考虑系统的非平稳性,通过建立armax模型,得到量角加速度和指示扭矩之间传的传递函数,从而实现基于瞬时转速的指示扭矩估计。 相似文献
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针对变量泵-定量马达容积调速回路调速范围有限,变量泵-变量马达调速回路结构复杂的问题,故提出采用力偶型径向柱塞马达的新型恒转矩调速回路。该马达输出轴的径向力平衡,通过力偶输出转矩,马达的一个壳体内可以形成内、外两个马达;在输入压力和流量不变的情况下,通过不同的配流方式可以输出三种转矩和转速,更能满足多种工况需求;三级恒转矩调速回路在三种工作方式下产生不同的动态特性,内马达单独工作时的动态特性较好。利用AMESim软件进行仿真分析并搭建实验台对力偶型径向柱塞马达新型调速回路进行试验分析,试验数据验证了新型调速回路可增加系统的转速转矩范围,丰富了力偶型径向马达的应用领域。 相似文献
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由于大功率船用齿轮箱的特殊使用工况,其性能要求远远高于其他齿轮箱。论文对某大功率船用齿轮箱结构和传动原理进行分析,根据试验模态分析的基本原理和方法,利用最小二乘法对频响函数进行优化,并利用单模态识别法对大功率船用齿轮箱进行模态参数识别,得出系统的前20阶固有频率和阻尼,结果表明该船用齿轮箱系统的转频、啮合频率远离固有频率,系统不存在共振现象。但考虑齿轮箱实际工作的复杂性,在系统转速变化达到临界转速时存在较为剧烈的共振现象。试验结果可为进一步系统研究动态特性提供分析依据。 相似文献
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针对多模态振动信号的在线监测和跟踪,提出基于随机子空间(SSI)和粒子滤波(PF)算法的仿真振动信号在线监测和跟踪方法。通过SSI算法提取得到振动系统的模态主频和阻尼比,根据振动系统模型模态主频和阻尼比的计算公式,得到系统的状态矩阵和输出矩阵。将计算所得状态矩阵和输出矩阵代入状态方程,利用PF算法进行信号的在线监测和跟踪,实现信号的降噪处理和预测分析。对于大型机械、桥梁等建筑物,对其进行在线监测保障其正常营运对社会经济发展具有深远影响。文中利用SSI算法提取系统的模态参数,进一步构建振动系统的状态矩阵和输出矩阵,并利用PF算法进行信号滤波抑噪和预测,在此基础上可以对结构状态实施在线监测及预警控制,实际大桥斜拉索振动信号测试也表明本文算法可以提供稳定可靠的信号跟踪与预测技术。 相似文献
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Y.B. Lee G.C. Lee J.W. Park B.J. Sung J.D. Yang 《Materialwissenschaft und Werkstofftechnik》2020,51(5):665-675
The power take-off (PTO) gearbox is widely used for special vehicles, large construction machinery, industrial machinery and ships, to distribute the power of a single input shaft from an engine or a motor to several shafts or to collect several shafts by single shaft power (Torque × rotation speed). The super large hydraulic excavator is equipped with a power take-off (PTO) gearbox between the main engine and a number of pumps for the purpose of improving the fuel efficiency and improving the system efficiency. The power take-off (PTO) gearbox of a large hydraulic excavator with a body weight of 100 ton ( = 105 kg) is connected with two large hydraulic pumps and one small hydraulic pump on three output shafts and different axial loads are generated depending on the working characteristics of the excavator. In this paper, we evaluated the performance and durability of a power take-off (PTO) gearbox of a large hydraulic excavator with a 100-ton body weight. The test evaluation criteria for non-fault life time calculation, performance and accelerated life test were established, and the types and characteristics of acceleration test equipment were analyzed. The torque distribution with the use of the gear phase difference to maintain the gearbox output condition was investigated, and energy was saved by circulating experimental power while controlling speed and load with two electric dynamometers. We analyzed the life of the gearbox by analyzing the metal particles generated in the lubricating oil of the gearbox. 相似文献
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基于高阶统计量具备处理随机信号的特性,提出了一种利用三阶谱(双谱)评定MIMO线性系统时域输入输出信号统计特征的新方法。通过建立线性系统双谱数学模型,根据系统响应、所测得的频响函数以及离散信号的双谱数值估计算法,经逆运算获得系统的双谱驱动信号,随后利用高阶谱对高斯随机信号的盲性判定其输入信号的高斯性。将上述方法与采用传统相位随机化法(对功率谱添加随机相位)所获得的驱动信号分别应用于一悬臂梁模拟控制系统中,通过对输入信号的分析及控制结果的比较,发现基于双谱所生成的时域随机驱动信号呈现出较强的非高斯性且收敛速度更快。对于输出信号统计特征的评定,提出从输入信号与系统频带接近的程度入手,再次利用高阶统计量对高斯随机信号的盲性进行定性判定,对于无法判别满足何种非高斯统计分布特征的,不管是对于输入信号还是输出信号,一律采用绘制信号的概率分布特征曲线进行定量评定。 相似文献
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齿轮箱非同步特征信号的提取方法研究 总被引:3,自引:0,他引:3
在分析时域平均的基础上,通过将齿轮箱输入轴瞬时速度的三次曲线拟合和信号重采样相结合,提出了非同步特征信号的时域平均提取方法.时域平均对从噪声中提取特定周期信号是比较有效的方法,但当信号的故障特征频率未知或存在多种故障时,该方法不能获得满意的诊断效果,而频域平均能较好的实现该类故障的特征提取.基于早期故障信号的特点,提出了将多分辨分析的经验模态分解方法与频域平均相结合的故障特征提取方法.试验结果表明,所提出的时频域平均方法能有效地实现齿轮箱非同步特征信号的提取. 相似文献
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高速列车在实际运行过程中,当路面不平顺、车轮磨耗或者列车由明线运行到突然进入隧道均可能会引起转矩脉动,引起齿轮箱振动加剧。为研究谐波转矩波动幅值对高速列车牵引齿轮箱振动加速度的影响,建立考虑时变啮合刚度、啮合阻尼、啮合误差、齿侧间隙的齿轮传动系统与三相异步动态电机耦合的机电传动系统模型,在Simulink平台上分析牵引传动系统在谐波转矩幅值变化的工况下齿轮箱输入端振动加速度特性。结果表明,谐波转矩增大使齿轮箱振动加速度加大,且横向振动加速度增加最明显。耦合系统叠加混合型自抗扰控制器(ADRC)后,对谐波转矩引起的齿轮箱横向振动具有较好的抑制作用。 相似文献
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针对液体黏性软启动装置的工作特点,要求输出轴传动力矩和输出转速变化范围较大,轴变形应该保持在较小范围内,输出轴的性能对液体黏性软启动装置正常工作有重要影响,需要对输出轴的结构作进一步分析.通过建立液体黏性软启动装置输出轴的Pro/E三维模型,采用有限元软件ANSYS Workbench对启动装置的输出轴进行有限元分析,确定输出轴的变形和应力状况,计算输出轴的模态和疲劳损伤.仿真结果表明:输出轴损伤最大部位位于较粗轴端键槽一侧.提出了一些改进措施,为液体黏性软启动装置输出轴的结构设计和疲劳寿命估算提供参考依据. 相似文献
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Kavanagh R.C. Murphy J.M.D. 《IEEE transactions on instrumentation and measurement》1998,47(6):1457-1463
This paper focuses on the nature of the rate error which arises when a first-order digital differentiator is applied to the output of a uniform quantizer for the purpose of rate estimation. The quantizer input is assumed to be a constant-rate signal which is subject to a uniformly distributed noise source. New formulae are presented for the corresponding rms and spectral error characteristics. The results are applicable to the signal processing of sensor outputs, exemplified by the shaft encoder-based velocity estimation of an almost uniformly rotating mass. Both computer-generated finite data sets and experimental data derived from encoder-based shaft velocity measurements are utilized to verify the theoretical results. The results described are also applicable to a more general class of systems which involve the digital differentiation of quantized, noise-affected signals, such as first-order sigma-delta modulators with nominally constant input 相似文献
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In this paper, a prognostic method is presented for fault detection in gears and bearings in wind turbine drivetrains. This method is based on angular velocity measurements from the gearbox input shaft and the output to the generator, using two additional angular velocity sensors on the intermediate shafts inside the gearbox. An angular velocity error function is defined and compared in the faulty and fault-free conditions in frequency domain. Faults can be detected from the change in the energy level of the frequency spectrum of an error function. The method is demonstrated by detecting bearing faults in three locations: the high-speed shaft stage, the planetary stage and the intermediate-speed shaft stage. Simulations of the faulty and fault-free cases are performed on a gearbox model implemented in multibody dynamic simulation software. The global loads on the gearbox are obtained from a dynamometer test bench and applied to the numerical gearbox model. The method is exemplified using a 750 kW wind turbine gearbox. The case study results show that defects in the high- and intermediate-speed bearings can be detected using this method. It is shown that this procedure is relatively simple, yet accurate enough for early fault detection in wind turbine gearboxes. 相似文献