Roller bearings with rational working surfaces and their manufacture

Russian Engineering Research -     

Floating ring journal bearings: theory, design and optimization

The performance characteristics and design data for journal bearings with a precise floating ring inserted between the rotating journal and a rigid housing are investigated theoretically. Based on convenient boundary conditions, a theory has been developed to predict the floating ring behaviour. Performance charts are presented with curves provided with optimum design areas to help in practical design applications. Induced ring speed, hydrodynamic behaviour, oil film variation, load capacity and frictional drag could thus be analytically or graphically determined. Results indicate that the ring dimensions are a dominant factor in deciding the final bearing behaviour and that the oil film thickness between the ring and the housing is much thinner than that between the journal and the ring. The floating ring bearing showed less frictional power loss than a fixed sleeve bearing, but this may have been achieved at the expense of the load capacity.     

Reliability-based design optimization of slider air bearings

This paper presents a design methodology for determining configurations of slider air bearings considering the randomness of the air-bearing surface (ABS) geometry by using the iSIGHT. A reliability-based design optimization (RBDO) problem is formulated to minimize the variations in the mean values of the flying heights from a target value while satisfying the desired probabilistic constraints keeping the pitch and roll angles within a suitable range. The reliability analysis is employed to estimate how the fabrication tolerances of individual slider parameters affect the final flying attitude tolerances. The proposed approach first solves the deterministic optimization problem. Then, beginning with this solution, the RBDO is continued with the reliability constraints affected by the random variables. Reliability constraints overriding the constraints of the deterministic optimization attempt to drive the design to a reliability solution with minimum increase in the objective. The simulation results of the RBDO are listed in comparison with the values of the initial design and the results of the deterministic optimization, respectively. To show the effectiveness of the proposed approach, the reliability analyses are simply carried out by using the mean value first-order second-moment (MVFO) method. The Monte Carlo simulation of the RBDO’s results is also performed to estimate the efficiency of the proposed approach. Those results are demonstrated to satisfy all the desired probabilistic constraints, where the target reliability level for constraints is defined as 0.8.     

基于遗传算法的轿车轮毂轴承数值优化

为了提高设计效率和质量,优化系统性能指标,在给定的装配空间条件下满足几何和性能约束,以获得最大的疲劳寿命为目的,运用遗传算法对双列角接触球轴承结构的轿车轮毂轴承进行数值优化设计。并基于一个实际例子编制了优化程序,给出了运算结果。结果表明,遗传算法能够有效地解决离散变量全局寻优问题,全部约束得到满足并且优化设计方案在系统疲劳寿命方面显著优于当前设计方案。     

Optimum design of short journal bearings by enhanced artificial life optimization algorithm

This paper presents an optimum design of high-speed short journal bearing using an enhanced artificial life algorithm (EALA) to compute the solutions of optimization problem. The proposed hybrid EALA algorithm is a synthesis of an artificial life algorithm (ALA) and the random tabu search method (R-tabu method) to solve some demerits of the ALA. The emergence is the most important feature of the artificial life which is the result of dynamic interaction among the individuals consisting of the system and is not found in an individual. The artificial life optimization algorithm is a stochastic searching algorithm using the feature of artificial life. The feature of R-tabu method, which prevents converging to the local minimum, is combined with the ALA. One of the features of the R-tabu method is to divide any given searching region into several sub-steps. As the result of the combination of the two methods, the EALA not only converges faster than the ALA, but also can lead to a more accurate solution. In addition, this algorithm can also find all global optimum solutions. We applied the hybrid algorithm to the optimum design of a short journal bearing. The optimized results were compared with those of ALA and successive quadratic programming, and identified the reliability and usefulness of the hybrid algorithm.     

绿色设计和绿色制造与其他先进设计制造模式

并行工程、精益生产、敏捷制造和绿色制造是现代企业的新型高效运行模式。他们之间不是相对、独立、互斥的关系,而是互相补充、互相促进、共同发展的关系。从图1可     

The anesthesia machine: current design and alternatives

The anesthesia machine is a major component in an integrated anesthesia care system. It can be considered in terms of the functional subsystems responsible for gas proportioning, anesthetic vapor delivery, patient ventilation, and waste gas scavenging. Alternative technologies for these functional units should be examined in light of the disadvantages inherent in present machines. Safety features, often added on an ad hoc basis, should instead be designed into the machine itself. The anesthesia delivery system should include feedback about the patient status and device performance, as well as provide for the delivery of anesthetic and pharmacologic agents. Improvements in performance and provisions for automation of some functions should be considered as future design criteria.     

Orifice compensated EP gas bearings: the significance of errors of manufacture

In recent years it has become possible to accurately model the performance characteristics of externally pressurised orifice compensated gas bearings. Also, and of equal importance, it is now possible to evaluate the effects of errors, and to establish the significance of these errors on the idealised bearing performance.This paper considers typical errors which are encountered in manufacture and the significance of each effect. Finally, evidence is presented which demonstrates the correlation that can be achieved between theoretical models and experimental measurements. The charts presented in this paper may be used by designers to assist in accurately predicting the performance of bearings whose errors of size and form (effect of tolerances) have been determined     

陶瓷球轴承内部结构参数优化设计及其性能试验研究

氮化硅陶瓷是一种较好的滚动轴承材料,在此提出了陶瓷球轴承内部结构参数优化设计的基本原则,建立了其优化设计的数学模型,通过对钢球轴承和陶瓷球轴承的性能对比试验,证明了陶瓷球轴承的高速性能要优于钢球轴承,并验证了陶瓷球轴承优化设计原则。     

Roughness and wear of frictional surfaces in slip bearings

Attention focuses on how the roughness and the configuration of microirregularities on the frictional surfaces of slip bearings affect their interaction and wear.     

消像差光栅的理论及实验研究

对消像差光栅进行了理论和实验研究。用光程函数和费马原理研究光栅的成像,用刻槽分布函数表示光栅的刻槽曲率及间距变化。对成像的理论分析表明光栅刻槽分布函数比刻槽间距更容易表达像差,给出了消像差光栅的表达形式。比较了SD、WFA、LPF等光栅的参数优化方法。探讨了消像差光栅密度的干涉测量法,设计了光路,对光栅密度进行了测量。     

An investigation of three-dimensional scanning of human body surfaces and its use in the design and manufacture of prostheses

The capture of highly accurate data describing the complex surfaces of the human body may prove extremely useful in many medical situations. The data provide a method of measuring and recording changes to the surface of a patient's soft tissue. The data may be applied to computer-controlled manufacturing techniques, such as rapid prototyping (RP). This enables accurate physical replicas of the patient topography to be produced. Such models may be used as an aid in the design and manufacture of prostheses. This paper describes an investigation aimed at identifying problems that may be encountered when scanning patients and describes the application of the resulting data in the design and manufacture of facial prostheses. The results of the experiment are presented together with a discussion of the accuracy and potential advantages afforded by this approach.     

利用AHP与PROMETHEE的产品设计方案优选方法

研究利用层次分析法(AHP)与排序组织法(PROMETHEE)进行产品设计方案排序与优选问题.在建立定性与定量相结合的决策准则体系的基础上,首先使用AHP确定属性权重,然后使用PROMETHEE计算偏好指标和各方案的净流,获得方案的完全序.该方法以设计者的目标与价值观为导向,又兼顾了属性信息的不确定性,具有一定的应用价值.     

面对制造和面对装配的设计

介绍了基于降低成本和提高生产率的设计——面对制造的设计 (DFM)和面对装配的设计 (DFA) ,并提出了实施 DFM和 DFA技术的策略     

胀紧联接套的设计及其制造加工技术

这里介绍了一种新型的传动无键联接装置……胀紧联接套的结构原理、型式以及设计、制造加工要点.该联接方式结构新颖,具有对中性好、无应力集中、拆装非常方便等优点,是一种值得推广应用机械联接基础件.     

空间凸轮的反求设计及制造

从设计纺机空间凸轮的角度，分析了空间凸轮的设计方法和设计规律。运用反求的方法，对反求三坐标数据的测量和处理方法进行了阐述，同时对纺机空间凸轮的加工规律和特性进行了剖析，充分利用先进的CAD／CAM集成软件Pro／Engineer强大的设计和加工功能，比较系统地设计了纺机空间凸轮。利用Pro／Engineer加工模块，对纺机空间凸轮进行了数控加工，生成数控加工程序。