摆线转子数控加工程序的研究

由于摆线转子一般采用粉末冶金工艺批量生产,所以需要解决复杂型腔模具精密制造的难题。通过研究转子泵工作原理、参数变化和制造工艺对齿形的影响规律,并运用计算机编程进行分析,从而获得粉末冶金工艺对摆线齿廓的影响规律,设计出转子模腔精密加工程序,最终形成模具,加工出转子。     

摆线转子式齿轮泵的设计

提出摆线转子泵流量、转速、转子的齿数和宽度、内外转子的齿隙和端面间隙等确定原则，分析了内、外转子间的相互关系。     

关于螺旋角β=0的圆弧齿轮传动运动学与动力学分析方法

从点啮合原理出发,对圆弧齿轮传动的运动学和动力学问题进行理论分析。论证了圆弧齿轮传动中螺旋角β、相对曲率半径PH与圆弧齿轮齿面接触强度的关系,讨论了当螺旋角β=0时,圆弧齿轮齿面丧失接触强度和导致齿面点蚀、剥落和磨损破坏的原因;论证了圆弧齿轮的滑比Vh／V2K、Vh／V1K、螺旋角β及圆弧齿轮啮合齿面形成油膜的条件与圆弧齿轮耐磨损性能的关系,讨论了当螺旋角β=0时,发生大齿轮齿顶和小齿轮齿面严重磨损的原因。     

关于螺旋角β=0的圆弧齿轮传动运动学与动力学分析方法（续）

从点啮合原理出发,对圆弧齿轮传动的运动学和动力学问题进行理论分析。论证了圆弧齿轮传动中螺旋角β、相对曲率半径ρdH与圆弧齿轮齿面接触强度的关系,讨论了当螺旋角β=0时,圆弧齿轮齿面丧失接触强度和导致齿面点蚀、剥落和磨损破坏的原因;论证了圆弧齿轮的滑比Vh/V2K、Vh/V1K、螺旋角β及圆弧齿轮啮合齿面形成油膜的条件与圆弧齿轮耐磨损性能的关系,讨论了当螺旋角β=0时,发生大齿轮齿顶和小齿轮齿面严重磨损的原因。     

大传动比滚子波动减速器

该专利是在摆线针轮减速机的基础上优化设计成的系列通用型减速器,是继行星齿轮传动、少齿差行星齿轮传动、摆线针轮传动、谐波齿轮传动之后的又一种新型传动,以滚动为主要啮合形式,传动效率高,磨损少。传动型式相当于3K机构和K-H-V机构     

5000kw冶金重载双圆弧齿轮减速机的研制和应用

经分析研究双圆弧齿轮减速机的特点和齿廓设计的原则，确定合理齿廓．并对双圆弧齿轮减速机的设计参数。制造工艺进行了阐述．介绍工业性试验情况．提出了双圆弧齿轮减速机的安装、跑合及检测方法。对提高传动质量、延长使用寿命至关重要。     

混匀取料机链传动跳链现象分析

分析了湘钢烧结料场混匀取料机链轮传动跳链现象产生的原因，认为主要是链轮齿廓变形引起，还对滚子链与链齿啮合时的受力情况以及啮合点的变化作了较详细的阐述，并据此提出了维修措施。     

面齿轮传动系统参数激励振动特性分析

为研究各参数对面齿轮传动系统动态特性的影响,建立了包含齿侧间隙、传动误差、时变啮合刚度、阻尼、支承和外激励等参数的系统弯-扭耦合非线性动力学模型,结合非线性动力学数值分析理论求解并得到了系统在不同参数下的分岔特性.计算结果表明,增加齿侧间隙、时变啮合刚度和传动误差会导致系统动载荷明显增大,而增加啮合阻尼则能有效降低系统的动载荷.     

基于模糊综合决策的直齿圆柱齿轮齿廓最佳修形

在时变啮合刚度和Blok闪温理论的基础之上,系统地分析齿廓修形参数对齿间载荷分配、传动误差和齿面闪温的影响,并确定在单目标条件下齿廓修形的最佳修形参数.基于模糊综合决策理论,确定了综合考虑多目标条件下齿廓修形最佳修形参数.引入多目标条件下修形量的修正系数X_c,确定修正系数X_c的值,并给出多目标条件下修形量的计算公式.综合最佳修形参数的最大修形量,取单双齿啮合区交替点B和D的变形量乘以修正系数X_c,修形指数取1.43,修形方式为长修形.      

圆弧齿圆柱蜗杆变位传动设计分析

根据设计理论与实践相结合的原则，结合鞍钢设备更新的需要，对圆弧齿圆柱蜗杆变位传动的设计和测量尺寸的计算、传动性能分析等问题进行了初步探讨。圆弧齿蜗杆传动是新型传方式，其承载能力和使用效率都比普通阿基米德效果好，因此将设计选择主要参数的统计规范化和设计中推导的计算公式作以介绍，供各厂矿推广使用是很有价值的。     

Roller pump induced tubing wear of polyvinylchloride and silicone rubber tubing: phase contrast and scanning electron microscopic studies

Tubing wear and spallation have long been recognized as complications of roller pumps used in cardiopulmonary bypass (CPB) although the reported results of studies of polyvinylchloride (PVC) and silicone rubber tubing wear are still controversial. We conducted phase-contrast microscope (PCM) and scanning electron microscope (SEM) studies of roller pump induced tubing wear. A closed CPB circuit was constructed, and both PVC and silicone rubber tubing (1/2 inch internal diameter [ID]) were tested under normal and tight occlusions of a dual roller pump at a typical CPB flow rate (4,500 ml/min) for 1, 2, 4, and 6 h in quintet. After each pump run, the tubing was removed. It was first examined with PCM, and suspicious portions were then analyzed in detail using SEM. In silicone rubber tubing of longer running time, the external diameter often decreased. Wear was invariably found on the luminal surfaces at the junction of the inner and outer walls of both the PVC and silicone rubber tubing with no significant differences between normal and tight occlusion. The grooves in the PVC tubing were narrow and continuous with occasional deep cracks in the tubing after more than 3 h of pump run. The grooves in the silicone rubber tubing were wide and often interrupted with occasional V-shaped elevated areas. Craters of less than 50 microns occurred sporadically in both types of tubing. Neither PVC nor silicone rubber tubing offers advantages in terms of roller pump induced tubing wear and spallation.     

Blood flow analysis for the secondary impeller of an IVAS heart pump

The rotodynamic heart pump (IVAS), designed by the Cleveland Clinic Foundation, includes a secondary flow path along the journal bearing, through a secondary impeller, and over the rotor outer surface. The flow behaviors of the blood through the journal bearing and the secondary impeller are investigated by a computational fluid dynamics method that solves the 3-dimensional Navier-Stokes equations using a new solution algorithm. Results of the analyses include: 1) the blood flow patterns within the journal bearing, 2) the effect of the non-uniform bearing clearance on the flow patterns of the impeller cavity, 3) the flow patterns around a secondary impeller blade that include effects of tip clearance and the gap between the blade and the inner or outer side wall, 4) effects of the blade angles on the secondary impeller performance, and 5) the shear stress distribution.     

双压力角非对称齿廓齿轮接触应力的计算研究

文章提出了工作齿面采用大压力角的双压力角非对称齿廓渐开线圆柱齿轮齿面接触应力的解析计算方法,推导出了双压力角非对称齿廓渐开线圆柱齿轮工作齿面在任意啮合点上接触应力的计算公式,特别就工作齿侧齿面在节点和小齿轮单对齿啮合区下界点处的齿面接触应力进行了研究。通过与常规的对称渐开线圆柱齿轮和工作齿面采用小压力角的双压力角非对称齿廓渐开线圆柱齿轮齿面接触应力对比,论证了这种双压力角非对称齿廓渐开线圆柱齿轮能够有效地提高齿面接触强度。     

The prevalence of early postpartum psychiatric morbidity in Dubai: a transcultural perspective

The surface roughness of artificial blood contacting devices is an important surface property that is closely related to blood cell trauma. The present study investigated the effect of the surface roughness of a pump housing on hemolysis in an impeller-type centrifugal blood pump, a pivot bearing supported Gyro C1E3 pump. The purpose of the study was to determine which part of a housing has the greatest surface roughness effect on hemolysis in a centrifugal pump. Seven Gyro C1E3 pumps were prepared, each with a smooth surface impeller and a housing with differing areas of altered surface roughness. Both top and bottom housings were divided into half subregions, each with the same area. Seven test pumps were produced by subjecting various subregions of the housings to vapor polishing and sandblasting. The treated surfaces were then examined by a surface profile instrument. Using these 7 pumps with different areas of altered housing roughness, in vitro hemolysis tests were performed simulating cardiopulmonary bypass (5 L/min, 350 mm Hg). The results of this study are as follows. First, the surface roughness of the top housing had a greater effect on hemolysis than that of the bottom housing. Second, on the surface of the top housing, the surface roughness of the outer half area had a greater effect on hemolysis than that of the inner half area. Third, on the surface of the bottom housing, the surface roughness of the inner half area had a greater effect on hemolysis than that of the outer half area. These findings concur with previous studies of flow patterns in pumps. Thus, it is expected that the method in this study, comparative in vitro hemolysis tests of the pumps with surfaces of the same roughness but different locations, can be used to detect the high shear area inside a pump.     

Wear Resistance of CO2 Corrosion Product Scale Formed at High Temperature

 To investigate the correlation between structure characteristics and wear resistance of CO2 corrosion product scales at high temperature and high pressure, an autoclave was used to prepare CO2 corrosion product scales on N80 steel in carbon dioxide corrosion environment. The correlation between wear resistance of the scales and many other factors, such as temperature, pressure, morphology, structure, velocity of fluid medium, sand grain size, and so on, was comparatively analyzed by a self assembled wear device, and the scale morphologies before or after being worn were observed by scanning electron microscope (SEM). And then the surface grain size and thickness of scale were measured. The results showed that the cross section of the corrosion scale was of a double layer structure, the outer layer of which was composed of regular crystals, whereas the inner layer was a thin scale of fine grains. The outer grain size and thickness of scale varied with temperature, and the initial wear loss was consistent with the surface grain size; at the same time, the total wear loss corresponded to the thickness of scale. Compared to wear resistance in different depths of the scale, it was found that the structure of scale was a double layer structure in cross section, and the wear resistance of inner layer was better than that of the outer layer; the closer the scale to the matrix, the greater was the wear resistance of scale; and the larger the size or the higher the rotary speed of solid grain in multiphase flowing medium, the more was the wear loss of scale.