表面致密化--一种提高烧结齿轮性能的有效方法

表面致密化与传统的粉末冶金方法相结合，可以显著改善烧结齿轮的疲劳及表面磨损性能。从而提高齿轮的寿命，同时使生产高性能齿轮的总成本降低，为用粉末冶金(PM)方法生产汽车变速箱齿轮提供了更大的可能性。本文着重讲述了使用这种方法生产高性能PM齿轮的工艺过程，同时介绍了测定致密化效果及齿轮性能的几种主要方法，并根据工艺过程比较了使用传统的机加工方法及本文所述的方法生产同性能齿轮的成本差别。最后，以两个实例分别介绍了使用上述方法对Volvo 850系第五挡变速齿轮及Scania载重车变速箱中行星齿轮的研发。     

EMT新牙箱的新挑战

很少有人知道变速箱有这样一个奇怪而形象的名称．以改变转速比的齿轮来形容变速箱，牙箱无疑贴近而有趣，它通常只被拥有数十年驾龄的老司机和维修工人知晓．而现在最新的变速箱技术已经远远超越了人们对齿轮的理解能力．“牙”也变得另类了。如果说普通消费者在购车前还在纠结于“手动”还是“自动”时，     

安钢高线减定径机变速箱传动分析

介绍了新型减定径机变速箱的变速原理 ,并对其齿轮系进行了分析和计算     

高品质变速箱齿轮用钢xcs-23的研发

xcs-23齿轮钢是一种新型的高品质变速箱齿轮用钢。通过优化连铸生产工艺与轧钢加热时间来改善钢材的纯净度与带状组织;研究了该齿轮钢的关键理化性能,实现了淬透性的稳定控制,纯净度的提升和奥氏体晶粒度的有效控制。     

三辊行星铜管轧机

专利申请号：0228027．97 公开号：2587539 申请日：2002．12．09 公开日：2003．11．26 申请人：戚建萍 本实用新型公开了一种三辊行星铜管轧机，主要由轧机床身及设于床身上的变速箱体组成，变速箱体上设有能带动铜棒的螺旋伞齿轮及传动平衡齿轮。在变速箱体的前部设有大盘和前支承，在大盘上设有行星齿轮和螺旋伞齿轮，该螺旋伞齿轮带动设于床身上的轧辊座上的轧辊头，     

矿用设备用油的介绍与选择(续1)

2 液力传动用油井下铲运机等自行设备,地面的工程机械和矿用大吨位卡车等,其传动常采用液力变矩器和动力换档变速箱(器)组成的液力循环系统。液力传动油既做为液力变矩器能量传递的工作介质,也做为变速箱的齿轮和     

电脉冲齿轮跑合机

衡阳冶金汽修厂修理变速箱齿轮齿合面,一直采用砂轮打磨修理工艺。修理时间长,一台变速箱需要2—3天;拆装次数多,劳动强度大;手砂轮打磨不仅很难保证准确的跑合面,影响质量,且砂尘飞溅,直接影响工人的健康。     

宝钢特殊钢分公司打造高端汽车零部件用钢

日前,宝钢特殊钢分公司研制的16MnCrS5汽车变速箱用齿轮钢新品,顺利通过了世界著名汽车传动系统制造商——德国格特拉克公司总部的材料质量评审。     

专利信息

专利名称:三辊行星铜管轧机专利申请号:0228027·97公开号:2587539申请日:2002·12·09公开日:2003·11·26申请人:戚建萍本实用新型公开了一种三辊行星铜管轧机,主要由轧机床身及设于床身上的变速箱体组成,变速箱体上设有能带动铜棒的螺旋伞齿轮及传动平衡齿轮。在变速箱体的前部设有大盘和前支承,在大盘上设有行星齿轮和螺旋伞齿轮,该螺旋伞齿轮带动设于床身上的轧辊座上的轧辊头,轧辊头的后部设有离合器总成。本实用新型适用于铜加工企业,特别适用于铜管加工。(王元荪)专利名称:高温镍氢电池用贮氢合金材料及制法专利申请号:02116369·3…     

怎样确定变速箱中润滑油池的油量

设备的润滑是设备维护工作中的重要部分,搞好设备润滑工作,是保征设备正常运转,减少设备磨损,防止和减少设备事故,降低动力消耗,延长设备修理周期和使用寿命的有效措施。许多工人在对变速箱进行加油润滑时,总是喜欢一次把油加得满满的,其实这种加油方法是很不对的。首先,变速箱的齿轮大     

Air pollution and mortality: issues and uncertainties

Results from 31 epidemiology studies linking air pollution with premature mortality are compared and synthesized. Consistent positive associations between mortality and various measures of air pollution have been shown within each of two fundamentally different types of regression studies and in many variations within these basic types; this is extremely unlikely to have occurred by chance. In this paper, the measure of risk used is the elasticity, which is a dimensionless regression coefficient defined as the percentage change in the dependent variable associated with a 1% change in an independent variable, evaluated at the means. This metric has the advantage of independence from measurement units and averaging times, and is thus suitable for comparisons within and between studies involving different pollutants. Two basic types of studies are considered: time-series studies involving daily perturbations, and cross-sectional studies involving longer-term spatial gradients. The latter include prospective studies of differences in individual survival rates in different locations and studies of the differences in annual mortality rates for various communities. For a given data set, time-series regression results will vary according to the seasonal adjustment method used, the covariates included, and the lag structure assumed. The results from both types of cross-sectional regressions are highly dependent on the methods used to control for socioeconomic and personal lifestyle factors and on data quality. A major issue for all of these studies is that of partitioning the response among collinear pollution and weather variables. Previous studies showed that the variable with the least exposure measurement error may be favored in multiple regressions; assigning precise numerical results to a single pollutant is not possible under these circumstances. We found that the mean overall elasticity as obtained from time-series studies for mortality with respect to various air pollutants entered jointly was about 0.048, with a range from 0.01 to 0.12. This implies that about 5% of daily mortality is associated with air pollution, on average. The corresponding values from population-based cross-sectional studies were similar in magnitude, but the results from the three recent prospective studies varied from zero to about five times as much. Long-term responses in excess of short-term responses might be interpreted as showing the existence of chronic effects, but the uncertainties inherent in both types of studies make such an interpretation problematic.     

关于变风量空调系统的探讨

文章阐述了变风量空调的基本原理,介绍了变风量空调系统的特点、分类和应用范围,总结变风量技术在空调系统的节能上是一种非常有效的系统形式。变风量技术的广泛使用将对我国建筑节能的推广产生深远的影响。     

矿井通风中的回风井经济风速

通过理论研究,分别得出回风井通风费用和基建投资的计算公式,二者的和为回风井通风的综合费用。再依据以回风井断面为变量的建设投资函数,得到回风井经济断面以及经济风速的计算公式。以某矿山为例,根据国内现有经济技术条件计算得出一般条件下回风井的经济风速为8~11 m/s。     

Development of Air Concentration on Chute Spillways

To protect hydraulic structures such as spillways, chutes, and bottom outlets against cavitation damage, air is normally added by means of aerators in regions where the cavitation number falls below a critical value. Although aerators have been investigated for more than 30 years, the current design methods for aerator spacing are not reliable. The detrainment process was not previously investigated in detail because of limited laboratory instrumentation. The research presented in this paper provides new model data for hydraulic chutes of variable bottom slope. An advanced remote-controlled, fiber-optical instrumentation was employed to investigate the streamwise development of air concentration contours, velocity contours, and air bubble size along a 14-m model chute. The main hydraulic parameters such as bottom slope, inflow Froude number, inflow depth, and two distinctly different air supply devices for air-water flow generation were employed. Results enable prediction of the reduction of bottom and average air concentration, depending on the inflow air concentration and the chute slope. The minimum air concentration is proven to be a function of the streamwise Froude number. The point of minimum air concentration is constrained by the point of air inception. Downstream of this point the air concentration increases from the surface aeration, depending on the chute slope.     

高压变频器在空气压缩机同步电机上的应用实践

本文介绍了利德华福同步电动机高压变频调速系统技术特点,和该调速系统在韶冶空压机站1^#空压机变频调速改造应用情况,实现了同步电动机高压变频调速功能,取得了良好的调速和节能效果。     

Understanding Air Release through Air Valves

Water transients with entrapped air can originate large pressure peaks that can severely damage distribution networks. Entrapped air can have a damping or amplifying effect on these undesirable pressure peaks. Unfortunately, the complexity of the phenomenon too often makes it difficult to obtain a fully reliable prediction about when air pockets will mitigate or accentuate water transients. Furthermore, the value of some of the parameters involved in the conventional numerical models cannot be calculated or measured and need to be determined through a calibration process. With the aim of overcoming most of the aforementioned uncertainties, this paper summarizes a complete set of tests conducted at WL | Delft Hydraulics. These tests were simulated by means of a tailored numerical model that includes a set of parameters whose values were determined by means of a calibration process. The experimental setup, a large-scale facility, consisted of a single steep pipeline with an air valve installed at its top end. Air release through different air valves was tested under different conditions.     

气垫炉退火段控制系统分析

阐述气垫式连续退火炉退火段的加热过程温度控制、变频风机转速控制、跳动辊微张力控制以及带材自动对中液压伺服控制等原理,为国内同行研究进口气垫炉的控制技术应用提供参考。     

浅析变工况操作对空分设备能耗的影响

介绍了空分设备能源消耗的特征,分析了空分工况的转换对机组能耗的影响,介绍了空分变工况的主要操作方式以及各个工序环节在工况调整时的能耗变化情况,结合实际效益数据,对比分析了主液氧工况和主液氮工况的综合效益变化情况,并提出了进行空分自动变负荷技术改造的思路。     

料仓清堵助流装置—空气炮的应用

料仓内物料起拱、堵塞是一较普遍存在的问题，采用空气炮破拱、清堵，改善料仓内物料的流动性是一种较理想的方法。本文介绍了国内外有关空气炮的开发研制和应用情况，以及空气炮的功能、特点和工作原理，给出了空气炮喷爆能量的计算方式，并对空气炮的选用方法及安装要点作了介绍，可供参考。     

降低烧结机系统漏风率的生产实践

对鞍钢股份有限公司炼铁总厂烧结机漏风情况进行了分析,提出了改造烧结机密封盖板等一系列措施。改造后6台烧结机平均漏风率由52.29%降到49.50%,工序能耗、电耗大幅降低,在原料变化比较大的情况下,保证了烧结生产稳定,满足了高炉用料要求。