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介绍了一种旋转固井用特殊螺纹接头(WSP-NF)高抗扭气密封套管的基本结构和设计思想,运用有限元方法,重点论述了该套管接头抗扭设计及密封设计的方法和准则,并通过全尺寸试验进行了验证。计算和试验结果表明:WSP-NF接头具有先进的扭矩台肩和合理的金属/金属密封结构,有效地克服了API螺纹和传统特殊螺纹接头的不足,具有优良的抗扭性能,气密封能力达到了管体内壁屈服压力。该研究结果可以为开发更多适合油气田实际的特殊螺纹接头套管提供参考。 相似文献
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《组合机床与自动化加工技术》1994,(4)
回转端面密封装置图1在机床上,常常通过回转端面密封装置给枪钻、枪铰和其它旋转加工的刀具输送压力冷却润滑液。装有端面滑动密封件4的接头体1支承在两个径向止推球轴承3内,该接头体拧紧在机床主轴尾部。与接头体7联接的壳体2套装在轴承3上,接头体1与主轴一起... 相似文献
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在深入分析了机械压力机气动摩擦离合器进排气用旋转接头所起作用的基础上,明确指出了该旋转接头必需具备的功能。详细对比分析了目前工业生产中常用的5种旋转接头的结构、各自的优缺点及其进一步改进的方案、适应范围和实际安装使用时应注意的问题,从而为进一步研制出更高性能的旋转接头及工业实际中的正确使用奠定了基础。 相似文献
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通过建立塑料检查井模具型腔刚强度有限元分析模型,采用正交试验设计方法研究了模具底部壁厚、周围壁厚及注射压力等参数对模具型腔刚强度的影响规律。结果表明:各参数对模具型腔应力、应变的影响程度均为:周围壁厚底部壁厚注射压力;模具型腔结构设计的最优参数组合为:底部壁厚20 mm、注射压力60 MPa、周围壁厚80 mm或100 mm。可为检查井注塑模具型腔结构设计提供参考。 相似文献
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《Acta Materialia》2004,52(1):161-171
Solute diffusion in an Al-rich binary Al–Mg alloy is studied by means of atomistic simulations. The activation energy for diffusion of Mg in the bulk is evaluated in the dilute solution limit for the nearest neighbor and the ring mechanisms. It is concluded that bulk diffusion at low and moderate temperatures must be assisted by vacancies. Further, diffusion of Mg along the core of edge, 60° and screw dislocations is studied. The activation energy for vacancy formation in the core and for vacancy-assisted Mg migration is evaluated for a large number of diffusion paths in the core region. It is observed that, similar to the bulk, Mg diffusion in absence of vacancies is energetically prohibitive. The paths of minimum activation energy are identified for vacancy-assisted diffusion, for all three types of dislocations. The lowest energy path is found in the core of the 60° dislocation, its activation energy being 60% of the activation energy in the bulk. Most diffusion paths have activation energies larger than 75% of the equivalent bulk quantity. This analysis is relevant for the discussion on the mechanism of dynamic strain aging in these alloys. The data presented here show that pipe diffusion, which is currently considered as the leading mechanism responsible for dynamic strain aging is too slow in absence of excess vacancies. 相似文献
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为了提高复杂机械产品装配序列规划的效率,提出了基于子装配的装配序列规划方法.建立了基于有向约束图的装配模型,并给出了基于子装配的装配序列规划系统框架,从而将产品装配序列规划问题转化为子装配的装配序列规划问题;给出了子装配的相关定义,并从稳定性和干涉性两个方面设计了子装配的识别方法;最后,给出了系统算法流程图,并通过电机车轴承箱装配实例验证了该算法的有效性. 相似文献
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《Acta Materialia》2003,51(12):3617-3634
Creep data from over 40 different polycrystalline alumina materials are reviewed. Most of these studies have attempted to describe the creep data using models based on diffusional creep. In the present paper, however, it is concluded that the dominant deformation mechanism in creep of fine-grained alumina is grain boundary sliding (GBS) accommodated by slip. The slip accommodation process is related to the sequential steps of dislocation glide and climb. When the accommodation process for GBS is that of dislocation climb, the stress exponent is always 2. In this case, the activation energy for creep is either that for oxygen ion diffusion in the lattice or that for oxygen ion diffusion in the grain boundary. When the accommodation process for GBS is that of solute-drag dislocation glide, the stress exponent is 1. For this case, the activation energy is that for solute diffusion at the dislocation site during glide. 相似文献
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针对水下焊接环境要求,设计了一种履带式水下焊接机器人系统,该系统由机器人本体机构、激光视觉传感器、控制系统和焊接系统组成. 机器人本体机构由履带式移动平台和焊枪调节机构构成,运动灵活可靠,满足水下焊接焊缝跟踪要求. 完成了视觉传感器部件选型及光路设计,实现水下环境的焊缝自动识别. 设计了基于PLC机器人控制系统和协调控制方法,实现水下环境的焊缝跟踪控制. 同时在水下焊接试验平台完成焊接跟踪试验. 结果表明,机器人运行稳定,焊缝成形较好,焊接质量满足要求. 相似文献
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A three-dimensional steady-state finite element analysis of square die extrusion by using automatic mesh generation 总被引:2,自引:0,他引:2
Steady-state finite element analysis is made for three-dimensional hot extrusion of sections through square dies by using an automatic mesh generator which can generate three-dimensional meshes by shifting two-dimensional meshes. In industrial practice, the design of extrusion dies is still an art rather than science, especially for complicated profiles, because the die design for a new extrusion is developed from previous experience and in-plant trials. The objective of this study is to develop a steady-state finite element method for hot extrusion through square dies, and to provide a theoretical basis for an optimal die design and process control for the extrusion technology. In the present investigation, steady-state assumption is used for both the analyses of deformation and temperature. The analysis of temperature distribution includes heat transfer, and is carried out by decoupling from the analysis of deformation. Convection link element is adopted for the heat transfer analysis between the billet and the container, and also between the billet and the die. Computations are carried out for solid and hollow extrusion of several sections. The present method of analysis has been shown to provide good results comparable with the non-steady-state method with reduced computation time. Distributions of temperature, effective strain rate, velocity and mean stress are discussed for effective design of an extrusion die. 相似文献
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分析了CAPP系统中工艺资源数据的特点,建立了工艺资源数据模型;研究了企业对工艺资源管理的要求,结合CAPP系统中工艺数据管理的要求和特点,提出了实用的CAPP系统的工艺数据库结构,并采用ODBC方法实现了对工艺数据的管理,同时为用户提供了方便快捷的工艺资源数据多条件查询,实现了企业对工艺资源数据的有效管理和利用。 相似文献
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空气开关内端轴零件的浇口设计优化研究 总被引:1,自引:0,他引:1
应用Moldflow软件对端轴零件的注塑模具中不同的浇口设计方案进行了流动模拟,对充模时间、锁模力、气穴和熔接痕等模拟结果进行比较,确定最佳的双浇口设计方案。其研究结果为进一步的浇注系统设计作了充分的准备,为优化模具设计提供了依据,从而可以提高制品质量,缩短模具设计制造和产品开发周期。 相似文献
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根据冲压工艺设计强经验弱理论的特点,提出采用面向冲压工艺设计的基于实例推理(CBR,case basedreasoning)功能模型及理论框架求解冲压工艺。较全面系统的阐述了面向冲压工艺设计CBR的7大关键技术,即冲压件及冲压工艺实例表示、冲压件实例检索、冲压工艺实例修改、冲压件及冲压工艺实例存储、实例库的创建和维护、反馈机制和合理性判别。其中,表示是基础;检索是手段;修改是目的;存储是自学习;实例库的创建和维护既是基础也是保障;而反馈机制的提出,则是实现CBR理论体系良好运行的关键;合理性判别,是正确引导CBR整个推理过程的必要条件。 相似文献