带止口花键的齿圈感应淬火工装的设计

针对行星轮系带止口花键的齿圈,中频感应轮齿部分,花键近齿顶部位出现淬硬不足或硬度不满足图纸要求的现象,设计一种感应淬火仿形工装,补偿了花键部位齿顶高与轮齿部位齿顶高的高度差,使花键部位与轮齿部位的硬度均满足设计要求,为装配使用行星轮系机械设备可靠运行提供了积极的便利条件,提高了设备的使用寿命。     

75kW中频感应加热电源的研制

针对中频感应加热电源对油田油井加热问题,本文采用PWM控制技术实现了功率可调。为使系统的功率因数较高,采用串联谐振和频率跟踪技术。中频感应加热电源采用IGBT作为开关器件,可工作在10 Hz-10 kHz频段。它充分利用中频趋肤效应、邻近效应和圆环效应原理,通过感应加热器和油管柱,使电能有效的转化为热能,从而达到原油降粘降稠、稳产高产的目的。     

论中频感应加热补口设备的优缺点

自工业开始应用感应加热能源，已过去将近80年了。在这期间，感应加热理论和感应加热装置都有很大发展，感应加热的应用领域亦随之扩大，其应用范围越来越广。在长输管道防腐补口领域，漠河—大庆输油管道工程第12标段上进行了热收缩带感应加热补口安装试验，后西气东输三线(东段)大面积推广使用这种感应加热工艺，即中频加热补口施工。     

水压高频淬火机床（专利申请号：200820089046．5）

本机床可与各种高、中频电源对接,广泛使用在机械制造业轴（管）、齿轮、链轮、突缘等机械零件的高频感应淬火工艺。本机床以水做动力,程序控制,机电一体化。在连续淬火工序中工件快速越程送进、旋转、工作送进及自动喷水冷却、停止送进、停高频电微越程冷却（工件不留软带）、快速复位、制动,各运动均为无级调速;在同时加热整体淬火工序中快速送进、工件旋转、加热、越程下跳、自动喷水冷却。本机床克服了油压传动高频淬火机床受制于温度、能耗大、噪音大的特点;克服了同类机械传动高频淬火机床动作灵活性差,易磨损的缺点。     

淬火机床中频电源谐波分析与处理

分析中频感应淬火机床在使用过程中电流检测模块过电流报警产生的原因,淬火过程中逆变电路产生的谐波对弱电信号检测的影响,对产品质量产生不可估量的风险。     

中频感应烧结炉故障处理及安全性能改造

通过研究中频感应烧结炉的加热原理及电气原理,结合实际的维修经验,详细阐述常见故障的现象,故障分析思路及维修方法,使广大维修人员能够快速准确的排除故障;通过研究分析近20年来中频感应烧结炉运行中发生的安全事故,找出事故原因,并进行改造研究,消除安全隐患,提高设备的安全运行性能。     

机车牵引电机轴承外圈拆装工具的研制

针对铁路机车牵引电机轴承外圈拆装检修困难的问题,利用中频感应加热原理研制加热器,对电机端盖加热使轴承孔膨胀、轴承松动,实现方便轴承外圈拆装检修的目的。     

高频感应加热设备产生寄生振荡的故障处理

什么是寄生振荡?简单地说非工作频率的振荡称为寄生振荡。常见的寄生振荡有两种,即低于工作频率的低频寄生振荡和高于工作频率的高频寄生振荡。对于高频感应加热设备危害最大的是高频寄生振荡。 寄生振荡的发生,是由于发射管极间电容、引线电感以及引线、扼流圈、电容器等元件的分布参数构成了振荡电路而产生的。 在高频感应加热设备上,一旦产生寄生振荡,就会出现下列现象:①高频输出功率很低,淬火工件无加热现象,但阳流、     

F005大功率曲轴中频淬火机床的研制

我厂引进新型柴油机其曲轴需要中频淬火,因本厂无此设备,曾试图外购曲轴中频淬火机床,对方报价需60万美元,工厂无此实力,而国内又无适当的设备可供选购.经调研并作了技术和经济可行性分析论证后,我厂决定自行设计制造1台大功率曲轴中频淬火机床,以满足引进柴油机曲轴中频淬火的需要.并从工厂对外经营开发的角度出发,要求该机床除能淬曲轴外,还能对光轴进行连续淬火.     

简述中频电源常见故障查找方法

中频电源是一种静止变频装置,中频电源在实际的工业生产中运用广泛,其可以将三相工频电源变换成单相电源,使得其的负载能力十分强大,这也是其之所以在工业各个领域中运用的如此广泛的原因.中频电源主要所使用的技术为中频感应加热技术,其通过电磁感应原理和涡流原理来实现的,本文主要针对中频电源常见的问题故障分析查找进行全面的分析,提出相应中频电源常见问题故障的分析查找方法,并且提出相应的故障解决措施.     

拖拉机驱动轮轴的中频感应淬火技术

对 8 0 -90和 90 -1 0 0拖拉机驱动轮轴感应淬火工艺进行了研究 ,在消化吸收国外有关技术资料的基础上 ,进行了感应器结构的设计和分析 ,工艺试验及检测结果表明 ,感应器结构设计合理、加热效果好 ,较好地解决了大台阶轴淬硬层不连续的问题     

拉、弯复合作用弯曲件回弹的理论分析

本文根据拉、弯复合作用下弯曲件的应力—应变,提出了该类弯曲件的回弹,由横截面上残余应力合力为零、合力矩为零两个过程组成;给出了该类弯曲件回弹半径及回弹角的理论计算公式。本文的理论分析可为施加轴向拉力提高弯曲件的质量提供理论依椐。     

Analysis of LPG,electric and induction cookers during cooking typical Ecuadorian dishes into the national efficient cooking program

This research aims to analyze cooking parameters in liquefied petroleum gas (LPG), electric resistance and induction stoves for eight dishes of the Ecuadorian cuisine. During tests, it has been monitored the temperature, time, electrical grid parameters, concentrations of CO and CO₂. In addition it has been studied the microbiological and physiochemical changes produced by the thermal treatment in food and a discriminative triangular test for determining the differences in the consumers perception between samples made with induction and LPG based stoves. The results showed which even with an exhaust hood working, there was still a significant value of concentration of CO and CO₂ during cooking with a LPG stoves. As a result of these analyses the induction stove shows a better response during the heating process and energy efficiency which have influence in temperatures, taste, vitamin preservation, cooking times, energy consumption and cost to the user.     

Positional rigidity: low performance and resource acquisition in large and small firms

Past research has given contradictory answers to the question of how strategic change is linked to firm size and performance. This paper resolves the contradictory predictions of performance feedback theory and threat rigidity theory by positing that small and large firms have distinct responses to performance because of differences in risk aversion and internal rigidity. To examine these differences, it is necessary to distinguish risk taking from rigidity in the strategic position, which is accomplished by separate analysis of the amount of resource acquisition and the difference of acquired and existing resources. Analysis of data from the shipping industry supports the predicted interactions of firm size and performance. Copyright © 2010 John Wiley & Sons, Ltd.     

Diversification,coordination costs,and organizational rigidity: evidence from microdata

This paper examines the impact of coordination costs and organizational rigidity on the returns to diversification. The central thesis is that coordination costs offset economies of scope, while organizational rigidity increases coordination costs, further constraining economies of scope. The empirical tests of this proposition identify the effects of coordination and organizational rigidity costs on business unit and firm productivity, using novel data from the Economic Census on taxicab and limousine firms. The key results show that coordination and organizational rigidity costs are economically and statistically significant, while organizational rigidity itself accounts for a 16 percent decrease in paid ride‐miles per taxicab in incumbent diversifiers, controlling for the other costs and benefits of diversification and incumbency. The findings suggest that coordination costs, in general, and organizational rigidity costs, in particular, limit the scope of the firm. Copyright © 2010 John Wiley & Sons, Ltd.     

企业核心能力的刚性特征及其超越

自“核心能力”被提出以来，该概念仿佛成了企业的“万能金钥”。然而，我们却不能忽视这一事实，核心能力容易走向其反面，形成刚性。核心能力刚性抑制了企业创新，严重削弱了企业创新的能力。本文首先提出了核心能力刚性的定义，然后分析了核心能力刚性的载体，进而对核心能力刚性的本质即路径依赖现象从三个角度进行了阐述，最后讨论了核心能力刚性特征的克服。     

OPTIMAL ECONOMIC TOOL REGRINDING WITH TAGUCHI'S QUALITY LOSS FUNCTION

One of the major cost components in tool economics is the cost incurred due to deviation in workpiece quality as a result of poor tool-cutting conditions. Commonly, the operating conditions of a culling tool may be restored via regrinding during periodic intervals of the tool's life. This paper proposes that optimal regrinding interval ought to be determined with respect to the optimal number of regrindings. The product of these two values defines the economic life of a tool. The objective function is the minimization of the sum of the expected costs of failure, regrinding, tool purchase, machining, and deviation in workpiece quality. The cost of deviation in workpiece quality is modelled using Tagucbi's loss function. The effect of cutting speed on tool regrinding interval is also explored.     

University – industry collaboration in R&D: the role of labor market rigidity

We investigate how R&D university – industry collaboration (R&D UIC) is influenced by labor market rigidity. While it is well-established that an educated and skilled workforce will facilitate R&D UIC, another aspect of these alliances has been under-researched: the role of labor market rigidity, in particular the difficulties employers face in hiring and firing workers. We hypothesize that the size of the R&D labor pool in a country will encourage R&D UIC, and that the ease with which employers are legally allowed to hire and fire will directly and indirectly influence R&D UIC. Integrating data from various sources, we test our model on a sample of 73 countries for which information on the size of the R&D labor pool and labor market regulations are available. We also conduct a robustness test using a different proxy for R&D labor pool on a larger sample of 109 countries. Results confirm the strong link between a country's R&D labor pool and R&D UIC, as well as direct negative impacts of hiring and firing rigidity and an indirect negative impact of hiring rigidity. The findings have implications for managers, policy makers, and researchers of R&D collaboration between universities and industry.     

国内外聚烯烃成核剂技术现状与应用趋势

成核剂是聚烯烃的功能型助剂，它可提高聚烯烃产品的刚性、透明性以及表面光泽度。近年来随着我国聚烯烃产品应用领域的不断拓宽，聚烯烃成核剂应用市场迅速发展，但由于我国成核剂起步较晚，在成核剂技术开发和市场应用方面均与国外有不同程度的差距。未来随着高透明和高刚性聚烯烃材料在我国市场的不断推广应用，高品质成核剂需求将会明显增加，这无疑对我国聚烯烃成核助剂产业发展提出更高的要求。     

基于接触力学的圆柱滚子轴承刚度对印刷压力的影响分析

以对开胶印机使用的轴承NNU4922-S-K-M-S为研究对象,基于接触力学理论,计算圆柱滚子轴承的静态载荷分布及刚度,分析了静态载荷分布及刚度与径向游隙、外加径向载荷的关系;利用有限元软件ANSYS建立压印滚筒模型,分析圆柱滚子轴承静态刚度对压印滚筒挠度的影响。研究表明：随着游隙的增大,最大负荷增大,轴承刚度减小,滚筒变形量增大,其结果是引起印刷压力下降。