Analysis and Design of the Globoidal Indexing Cam Mechanism

We first design and analyze the contour surface of the globoidal indexing cam with the aid of computer, and then do optimum design according to the requirements of dynamics. Finally, we discuss the problem of the pressure angle of the globoidal indexing cam mechanism in detail and put forward a new concept of equivalent pressure angle.

CONJUGATE CAM WITH FIVE-BAR LINKAGE MECHANISM FOR RAPIER DRIVE OF FLEXIBLE RAPIER LOOMS

A new type of rapier drive for flexible rapier loom through conjugate cams with five-bar linkage mechanism is raised and analyzed. Two designs suitable for the conversion of 1515-190.5 shuttle looms are given as examples. This mechanism can be applied to traditional shuttle looms as well as to new flexible rapier loom design.

A Parallel Indexing Cam Mechanism with Internal Placed Followers

A new type of parallel indexing cam mechanism is discovered.The composition of the cam profile is proposed and the formulas of the mechanism parameters are established by synthesis of its configuration and size.The equations for working pro- file and pressure angle of the cam are derived based on the inverse model and the derivative of pitch curve of cams.An example is given and demonstrates that it is available to design the new mechanism using the derived expressions.

Reverse Solution and Parametric Design of the Conjugate Cam Weft Insertion Mechanism Based on VB.NET and UG

In order to realize the parametric design of the conjugate cam weft insertion mechanism,according to the necessary parameters of weft insertion process,ideal kinematic curves of the weft insertion mechanism were given,and the mathematical model of reverse solution for this mechanism was established.The parameters of this mechanism were obtained by reverse solution on the basis of the given ideal kinematic curves and kinematic requirements.The parametric design platform which was integrated with the functions of parametric reverse solution,motion simulation,three-dimensional modeling and virtual assembly was developed based on VB.NET and Unigraphics(UG) NX.After entering the technological parameters of weft insertion process and essential structural parameters by users,three-dimensional drawing of the main parts such as the conjugate cam and shaft,can be obtained by this platform,also the processing data of the cam can be calculated.This platform provides a rapid approach for parametric design of weft insertion mechanism.

Prediction for Dynamic Characteristics of Ring-Plate Planetary Indexing Cam Mechanism

This paper is aimed to propose an approach to predict the dynamic characteristics of ring-plate planetary indexing cam mechanism, which is a novel type of indexing mechanism that employs internal planetary transmission structure. Firstly, the geometry and structure of the mechanism are discussed and the kinematic practicability is simulated with virtual prototype design. Then a 3D finite element model of the ring-plate planetary indexing cam mechanism is developed with the commercial software of MATLAB and ANSYS. Through the finite element analysis, the natural frequencies and the corresponding mode shapes are predicted in one motion cycle. On the basis of the virtual prototype design and finite element analysis, an experimental prototype is made and tested to validate the prediction of the dynamic characteristics. The agreement between experimental results and the finite element analysis testifies that the finite element model developed is applicable to the prediction of the dynamic characteristics of this type of mechanism.

THE DESIGN OF A NEW OUTSIDE TYPE CONJUGATE CAMS FOR SHEDDING MECHANISM

In the usual shedding mechanism of a weaving loom, the conjugate type of cams can be designed precisely according to any regular pattern sequence of heald frame motion to suit the weaving technological requirements. As this mechanism is also quite simple, with smaller cam size and better technological function, it is therefore very important and worthwhile to study this type of conjugate cams. In this paper, we try to analyze the defects of the traditional and some abroad type outside conjugate cams shedding mechanism, and propose a new improved design of this type of conjugate cams and then work it out finally.

An investigation of cam-roller mechanism applied in sphere cam engine

As an alternative power source for hybrid electrical vehicle(HEV), electric generating system(EGS) driven by sphere cam engine(SCE) is said to own higher power density and integration. In this work, the structure and working principle of EGS were introduced, based on which the advantages of EGS were displayed. The profile of sphere cam was achieved after the desired motion of piston was given. After establishing the dynamic model of power transmission mechanism, the characteristics of cam-roller mechanism were studied. The results show that the optimal cam profile of SCE is a sinusoid curve which has two peaks and two valleys and a mean pressure angle of 47.19°. Because of the special cam shape, the trace of end surface center of piston is an eight-shape curve on a specific sphere surface. SCE running at speed of 3000 r/min can generate the power of 33.81 kW, which could satisfy the need of HEVs. However, the force between cylinder and piston skirt caused by Coriolis acceleration can reach up to 1182 N, which leads to serious wear between cylinder liner and piston skirt and may shorten the lifespan of SCE.

Follow-Up Study of a Multiple Myeloma Patient Successfully Treated with Clarithromycin (CAM), Low-Dose Lenalidomide and Low-Dose Dexamethasone: Significance and Possible Mechanism of Action of CAM as an Add-On Therapy

Background: Recently, high efficacy of the chemotherapeutic regimen combining clarithromycin (CAM) with lenalidomide (Len) and dexamethasone (Dex) (BiRD) in treating multiple myeloma (MM) patients has been reported. However, the exact mechanism of added CAM has not been fully elucidated. This case report will provide helpful information for understanding the significance and the mechanism of action of CAM as an add-on therapy. Patient: A 78-year-old female patient with IgA-λ type MM was treated with low-dose Len coupled with low-dose Dex (low Rd), and excellent response was achieved for long term, but she later became refractory to this treatment. Then, CAM was added to low Rd (low Rd-CAM, i.e., modified BiRD therapy). This add-on-therapy was found to be effective, but later suspended because of pneumonitis. Then, low-dose Len coupled with CAM (low R-CAM) treatment was applied;but effect of this Dex-free treatment was insufficient. Thus, low Rd-CAM was reapplied and satisfactory reduction of IgA was achieved. This fact suggests that low Rd-CAM is the favorable combination, Dex is requisite and CAM might have enhanced the effect of Dex. In this case, various serum cytokines were examined during the course of illness. Only interleukin-6 showed apparent increase, and tumor necrosis factor-α, transforming growth factor-β, soluble IL-2 receptors and C-reactive protein showed the slight increase during low Rd-CAM treatment. The results seem somewhat conflicting, but it seems that intricate cytokine response due to immune activation might have occurred during low Rd-CAM treatment.

Mechanism Design of Palletizing Robot Based on Translating Cam Principle

Palletizing robot technology has been applied more and more extensively in logistics automation field.But there are some limitations in the current single-arm palletizing robot that it cannot do effective work in the process of moving back to the taking-end and the mechanical arm has so many freedoms that its control system is relatively complex.Based on the translating cam principle,a novel palletizing robot is designed.The horizontal movement of the palletizing mechanical arm is controlled by changeable outer slides,and the vertical movement is controlled by partitioned up-and-down spindles.To improve palletizing efficiency,the single palletizing mechanical arm is changed into multi-arm.Moreover,to improve its kinematic properties,the acceleration operating performance,joint driving force and palletizing trajectory are optimized through the multi-objective delaminating sequence method.According to the optimization results,the 3D model of the multi-arm palletizing robot is built in Pro/E,and the kinematic simulation is made.The simulation results show that the novel mechanism and optimization parameters are rational and feasible.This novel palletizing robot has the advantages of cam mechanism,so it simplifies the driving mode of palletizing movement and can lower the requirements for controlling system.At the same time,it can increase palletizing efficiency further by adding mechanical arms.

Analysis and Design of Conjugate Cam Shedding Mechanism with Dual Driving Shafts

The principle of conjugate cam shedding mechanism forthe outside tappets with dual driving shafts is discussed,and its design conditions and parameters are studied,giving the results of practical calculations finally.

FUZZY DESIGN SYSTEM OF CAM MECHANISMS

On basis of the computer a fuzzy design system is developed for the design of cam mechanisms. The system includes a fuzzy knowledge base, a virtual knowledge base,a fuzzy design mathematical model,a fuzzy design procedure which can complete the conventional fuzzy design and the fuzzy design optimisation.It can draw on the designer's wisdom better,and enhance the design quality and efficiency.

用Pro/Mechanism实现复杂凸轮机构的设计及运动分析

针对复杂平面运动从动件盘形凸轮机构设计的困难,介绍1种利用Pro/Mechanism的强大功能实现复杂凸轮机构的创新设计、运动仿真及运动分析。这种创新方法可以使复杂凸轮机构设计变的快捷、便利。

Development of a Leg Mechanism for Soft Landing Based on Biological Motion

With jumping mechanisms,soft landing motion is important to protect loads and the mechanisms.This study proposes a leg mechanism for soft landing based on biological motion.Human jumping motion with a load suggests a unique motion for soft landing.The landing model consists of two periods.Jerk is minimized in the first period and force is minimized in the second period.In comparison with other landing models,this model is specialized for soft landing motion protecting an objective part.Given all mechanisms have mass,such model is useful in practical application.For the purpose of realizing soft landing motion,this study proposes a new leg mechanism.The mechanism achieves quick variable transmission with cam and wire.Design process of the cam is explained with dynamics and computation.With the calculated cam shape,the leg mechanism can be driven by constant input voltage for simple control.Robustness against height change is also verified with landing simulation.With 50mm falling experiment,prototype leg mechanism performed soft landing without bounce motion and large sound.The acceleration profile of the body also agrees with the proposed soft landing model.

Kinematic Characteristics Analysis and Parametric Solving of Snow Melting Agent Throwing Mechanism with Variable Crank Length

Variable crank length cam⁃linkage mechanism has attracted much attention due to its compact overall structure when realizing complex motion laws.According to the special trajectory requirements,the kinematic characteristics and parameters of the mechanism have been analyzed and solved,which lays foundation for the implementation of the variable crank length snow melting agent throwing mechanism designed in this paper.Based on the trajectory equation of the point,the mathematical model of the throwing mechanism was established,and the theoretical trajectory of the end point of the throwing mechanism was obtained by programming.The parametric modeling and trajectory drawing were carried out by computer aided three⁃dimensional interactive application(CATIA),and the correctness of the mathematical model was verified by comparison.The regional trajectory distribution characteristics of the end points of the throwing mechanism were studied by using the trajectory region location method,and the influence of various parameters on the trajectory was investigated by using the numerical cycle comparison method.The human⁃computer interaction system of snow melting agent throwing mechanism with variable crank length was constructed by using Microsoft Visual Basic(VB)software.Based on the restriction conditions,the optimum combination of structural adjustment parameters and operational parameters suitable for Harbin first⁃class roads was obtained by using orthogonal test table,which provides an effective method to solve the parameters of the variable crank length cam mechanism with smooth impulse trajectory.

A New Thread Guide Mechanism of Rubbed Roving Frame

A new thread guide mechanism of a rubbed roving frame is developed, which consists mainly of a plate cam, a linkage and an air bag spring. Characteristics and design parameters of the air spring are explored in this study. Based on analyses of winding technology for this kind of package, the kinetic laws of the thread guide is put forward. General design equations of the cam profile are derived, and common kinetic laws of II linkage group which is used for such mechanism design is proposed. It proves theoretically that it is practicable. The experimental results indicate that it can meet the needs of technological demands, and the new thread guide mechanism has been used successfully on textile machines.

Mechanism of Excited State Double Proton Transfer in 2-Amino-3-Methoxypyridine and Acetic Acid Complex

The excited-state double-proton transfer （ESDPT） mechanism of 2-amino-3-methoxypyridine and acetic acid com- plex is studied by the density functional theory （DFT） and time-dependent DFT with CAM-B3LYP functional. The complex is connected through two different types of inter-molecular hydrogen bonds. After photo-excitation, both hydrogen bonds get strengthened, which can facilitate the ESDPT reaction. The scanned potential energy curve along the proton transfer coordinate indicates that the ESDPT reaction proceeds in a stepwise pattern.

DYNAMIC ANALYSIS OF A LATE-MODEL DOBBY SHEDDING MECHANISM

This paper presents the dynamic analysis of a dobby shedding mechanism. Taking theoscillatory slider as a moving reference frame, relative motion relations of the cam-rocker mech-anism are established in the kinematic analysis. A non-linear equation is solved by indirectmethod to obtain its numerical solutions expressed in algebraic power series for the six-barlinkage. In dynamic analysis, the authors have set up dynamic equations for the entire mecha-nism to find the solutions. From the results of dynamic analysis, it can be seen that the mecha-nism is suitable for operation at high speed and under heavy load.

一种基于低速风洞大迎角装置的Cam变量赋值法

在风洞试验装置的设计和运行中,多轴同步类运动机构的控制质量直接影响着模型的运动范围、气动特性的准确性。以4 m×3 m风洞大迎角尾撑机构为例,为保证该设备的控制准确度,运动轴之间的耦合关系由“一主一从”发展为“一主多从”和“多主一从”,而传统电子凸轮存在耦合关系单一的问题。针对上述问题,提出一种基于电子凸轮的Cam变量赋值法,将基于多项式计算的轨迹生成方式和动态生成关键点型电子凸轮表相结合,使系统不再局限于单一变量引导的控制模式,极大地减少了电子凸轮之间的切换次数,降低了设备的计算负荷和运行时间,适用于需要执行多轴联动的运动机构。

机械制图课程中CAD/CAM集成技术应用研究

CAD/CAM技术在机械制图课程中的应用是当前教育领域的热点之一。该文旨在探讨CAD/CAM集成技术在机械制图课程中的应用研究,通过分析CAD/CAM技术应用课程标准,明确了教学目标和内容,针对机械制图课程中CAD/CAM技术应用的课程实施,提出了具体的教学方法和步骤,以确保学生能够全面掌握CAD/CAM技术的基本原理和操作技能。通过对底座零件的实体造型进行教学案例分析,展示了CAD/CAM技术在机械制图课程中的具体应用过程和效果。研究结果为提高机械制图课程教学质量和学生实践能力提供了重要参考和借鉴。

凸轮机构CAD/CAM研究的回顾与展望

介绍了凸轮轮廓设计、凸轮机构CAD/CAM及其网络化的最新研究进展,评述近期发表的文献。最后在分析国内外电子凸轮研究现状的基础上,对电子凸轮系统的优点及应用前景进行了展望。