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1.
用解析方法推导出渐开线齿轮实际齿廓(包括渐开线和过渡曲线)的保角映射函数,计算方便,而且映射精度高,应用皮映射函数求得渐开线直齿轮轮齿挠度的精确解;编制了计算程序;对影响挠度的因素及其影响规律进行了分析。  相似文献   

2.
渐开线外齿修缘插齿刀的设计   总被引:1,自引:0,他引:1  
目前,越来越多的渐开线齿轮齿顶要求修缘,这样有利于提高啮合质量。因此,用修缘插齿刀来加工需要修缘的齿轮是一种很有效的加工方法。分析了渐开线外齿修缘插齿刀的设计,给出了具体的计算方法。  相似文献   

3.
渐开线齿轮的直接生成   总被引:4,自引:0,他引:4  
提出用圆弧来代替渐开线齿形的近似方法,实现了渐开线齿轮三维实体造型的直接编程生成技术。它是将齿轮的廓线用3段相切的圆弧来近似,便于编程,无需人机交互,在AutoCAD2000中比较近似法和精确廓形的偏差,比较结果表明近似法是可行的,在三维软件Autodesk Inventor中用VBA编程实现了这种思想。  相似文献   

4.
一种渐开线齿轮横截面积的精确算法   总被引:3,自引:0,他引:3  
根据渐开线齿廓的曲线方程,运用数值计算方法和CAD技术,得出了一种渐开线齿轮横截面积的精确计算方法。实测结果表明,该算法可靠实用,计算精度高,是一种值得推广的齿轮横截面积精确算法。  相似文献   

5.
赵鹏 《科技信息》2009,(27):69-70
本文介绍了球面渐开线的形成过程,并给出球面渐开线的数学方程。应用MATLAB的数值计算功能计算出球面渐开线上点的坐标值,在Inventor环境下,导入MATLAB计算出的球面渐开线上点坐标数据文件建立齿形曲面,利用其强大的实体造型功能,完成弧齿锥齿轮的三维实体造型及有限元分析。  相似文献   

6.
用边界元法的原现分析研究渐开线圆柱直齿轮的本体温度,提出计算用的齿轮模型,编制了计算程序,对实例进行计算,对影响齿轮本体温度的主要因素进行了分析。  相似文献   

7.
讨论了通过两个三重点的曲率严格单调的 C~2—类曲线的计算问题;证明了用圆的渐开线拼接的可行性;给出了用四段圆的渐开线拼接曲率严格单调的 C~2—类曲线并通过给定三重点的算法。同时,还给出了一种计算通过两个三重点曲率近似单调的曲线方法。  相似文献   

8.
用解析方法推导出渐开线齿轮实际齿廓(包括渐开线和过渡曲线)的保角映射函数、计算方便,而且映射精度高,应用此映的函数求得斯开线直齿轮轮齿挠度的精确解:编制了计算程序:对影响挠度的因素及其影响规律进行了分析,  相似文献   

9.
本文用月形环面截线逼近渐开线齿廓;用极小极大方法寻找渐开线齿廓的最佳近似月形环面截线参数,逼近误差仅为文[1]、[2]的35%~70%,从而大大提高了逼近法修整渐开线成形砂轮的逼近精度,为逼近法展现了新的前景。为了简化计算,本文直接运用曲线的隐式表达式定义误差函数,并证明了这种方法的合理性。  相似文献   

10.
渐开线外花键挤压成形的上限解   总被引:3,自引:0,他引:3  
对于渐开线外花键的挤压工艺,因齿面为渐开线型,所涉及的参数又很多,给理论分析带来一定的难度,因此目前多用试验方法寻取一些工艺参数,作者提出用上限法进行理论分析,其中包括两个扇形单元和一个渐开线单元,用该方法可取得良好的上限解,为制定工艺参数提供了一种理论分析方法。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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