Multi-objective iterative optimization algorithm based optimal wavelet filter selection for multi-fault diagnosis of rolling element bearings

Rolling element bearings (REBs) play an essential role in modern machinery and their condition monitoring is significant in predictive maintenance. Due to the harsh operating conditions, multi-fault may co-exist in one bearing and vibration signal always exhibits low signal-to-noise ratio (SNR), which causes difficulties in detecting fault. In the previous studies, maximum correlated kurtosis deconvolution (MCKD) has been validated as an efficient method to extract fault feature in the fault signals. Nonetheless, there are still some challenges when MCKD is applied to fault detection owing to the rigorous requirements of multiple input parameters. To overcome limitation, a multi-objective iterative optimization algorithm (MOIOA) for multi-fault diagnosis is proposed. In this method, correlated kurtosis (CK) is taken as a criterion to select optimal Morlet wavelet filter using the whale optimization algorithm (WOA). Meanwhile, to further eliminate the effect of the inaccurate period on CK, the update process of period is incorporated. After that, the simulated and experimental signals are utilized to testify the validity and superiority of the MOIOA for multiple faults detection by the comparison with MCKD. The results indicate that MOIOA is efficient to extract weak fault features even with heavy noise and harmonic interferences.     

Drag Power Loss Investigation in Cylindrical Roller Bearings Using CFD Approach

In high-speed rolling element bearings, the drag forces can be prominent and it is demonstrated in this investigation that the classical models may not be appropriate for correctly estimating this power loss contribution. A modification of the models is thus proposed, including the usual drag forces formulation relying upon the drag coefficient to be evaluated from a numerical computational fluid dynamics (CFD) approach. A three-dimensional approach that considers both the rings and the cylinder ends seems the only adequate approach to be used because a two-dimensional approach predicts a drag coefficient value that is too low. When using the former computed drag coefficient for the evaluation of the total power losses, high values of oil volume fraction must be employed to recover the measured power losses.     

基于旋滚比的电主轴轴承预紧力优化研究

为研究不同工况下轴承预紧力对电主轴轴承动力学的影响规律，基于外轨道控制理论,建立了一种以旋滚比可优化的轴承预紧力动力学模型。通过分析高速状态下滚动体载荷和特征参数动态变化过程，构建综合考虑滚动体滚动、自旋转、陀螺运动和离心力的轴承动力学分析模型，在此基础上，计算旋滚比动态变化结果；研究Jones发现的阈值与旋滚比之间的动态定量映射关系；以轴承滚动体打滑状态为优化目标，使用MATLAB仿真分析不同工况下轴承最佳预紧力。建模分析表明，轴承旋滚比大小可以反映轴承预紧效果，也可实现轴承预紧力动态定量优化。     

红岭矿18线南西翼通风系统技术改造

针对矿山18线南西翼矿体开采过程中存在的通风系统不完善、风量欠缺、污风无法及时排出等问题，运用风压平衡原理、网络优化技术、机站优化技术以及计算机网络模拟技术展开研究，拟定了3种可行的通风方案。经技术经济比较，确定了新掘18线905～855 m回风井（1.5 m），保留该井905 m 水平回风机站，并在855 m 水平新设1台K45 6 №12风机（18.5 kW）方案。数值模拟结果表明：18线南西翼通风系统总风量达到20.5 m3/s，井下风流的可调性和稳定性增强，为矿山的安全生产提供了有力保障。     

Effects of brand anthropomorphism on consumer-brand relationships on social networking site fan pages: The mediating role of social presence

This study aimed to investigate the effects of brand anthropomorphism on consumer-brand relationships in a social media marketing context. We hypothesized that anthropomorphism on a brand’s Facebook fan page can strengthen the relationships between brands and consumers by yielding both social presence and a positive inference regarding the brand’s quality as a relationship partner. Our longitudinal experiment confirmed the effects of brand anthropomorphism on consumer-brand relationships on social media and the mediating role of social presence. The results suggest that when the anthropomorphized brand had relationships with consumers, a favorable attitude was shown toward the brand. Further, the participants perceived the anthropomorphized brand as a trustworthy relationship partner, giving more “Likes” for the posts from the anthropomorphized brand than those from the non-anthropomorphized brand. Further, the results confirmed that these favorable relationships were maintained even after the participants became aware of a brand transgression.     

基于双离合变速器电控单元的Volcano CAN开发

Volcano 是集汽车电子网络设计、实现和测试于一体的完整工具链。它包括整车网络规划及优化设计工具VNA,网络节点(TCU等)实现工具VTP以及网络测试工具Tellus。本文着重介绍了基于TCU的VTP。     

印尼BAYAH电厂一次风机故障原因分析与处理

本文针对印尼BAYAH电厂一次风机设备故障，详细的分析了故障产生的原因，介绍了三点法找转子动平衡和工装车削式在线修复电机滑环工法，阐述了两种工法的原理以及实施步骤。     

矿井多级机站可控式通风系统的研究与实践

本文对矿井多级机站可控式通风系统研究工作作总结，并列举了工业应用情况，说明多级机站可控式通风技术是一种节能、易于风量痫节等特点的新技术。     

滚动轴承可靠性设计计算方法

从滚动轴承的可靠性设计理论出发，研究了在不同的目标可靠度要求时滚动轴承奉行命与目标可靠度间的关系；额定动载荷与目标可靠度间的关系。通过对ＸＹ—２型钻机轴承寿命与可靠度的计算，找出了该钻机中可靠度低的轴孢，提供用户注意维护与检修。     

汽车底盘技术在HGY-1500型钻机中的应用

在HGY-1500型钻机的设计中应用汽车底盘技术，选用汽车变速器、离合器等零部件；钻机分动箱采用斜齿圆柱齿轮传动，使用接合套式换挡装置进行换挡，提高了钻机工作的可靠性，降低了生产成本，减轻了钻机质量，操作轻松、方便。