常数度的结构化P2P系统Cycloid研究

基于分布式哈希表的结构化P2P系统要维护严格的网络拓扑结构,在网络搅动剧烈时大量节点的加入和离开会产生巨大的开销。因此,维护较少的常数个邻居节点成为一些新的P2P系统的良好性质。Cycloid系统基于著名的立方体连接环(CCC),每个节点只要维护7个邻居,而具有O(logN)的网络直径。

FORCE ANALYSIS CONSIDERING MANUFACTURE ERROR OF PIN-HOLE-OUTPUT MECHANISM IN CYCLOID DRIVE

Based on the analysis of the pin-hole-output mechanism in the cycloid drive,a more accurate force analysis method is provided, in which the manufacture error is considered, bywhich the contact force between pin and pin-hole can be calculated more accurately in the wholedriving process.

CT-Cycloid:一个基于Cycloid的抗Churn的P2P系统

Cycloid是一种常数度结构化P2P覆盖网,它具有高扩展性、自组织、自适应开销低等优点,然而像所有其它的常数度P2P覆盖网一样,它不能很好地适应高churn环境。为解决这一问题,在一个简单而新奇的设想的启发下,基于生存期的策略和角色划分机制被应用来对Cycloid的设计进行改造,构造了一个基于Cycloid的具有高抗churn能力的结构化P2P系统——CT-Cycloid。在CT-Cycloid系统中进行路由和定位的开销是O(logS),远低于一般系统中的O(logN)(S=N/logN)。大多数节点到来和离开时仅仅需要发送一条一跳到达的信息,节点的失效会很快被检测到,网络很快得以恢复稳定。理论分析和仿真实验都证明了CT-Cycloid与Cycloid相比查询路径更短,适应高churn环境的能力更强。

EFFICIENCY ANALYSIS OF DOUBLE CRANK RING-PLATE-TYPE PIN-CYCLOIDAL GEAR PLANETARY DRIVE

From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental study has been conducted. The tested value of theefficiency of a sample set of the new-type drive in the experiment agrees with the calculated one.It shows that the new-type drive is of not merely high bearing capacity, but also quite highefficiency.

Cycloidal Magnetic Gear Speed Reducer

A cycloidal speed reducer employing gears with permanent magnets acting as teeth is described. The magnets, which have their axes radially oriented in both the orbiting gear and the fixed internal gear, are inserted in holes drilled in nonmagnetic rims without protruding from the cylindrical exposed surfaces. Because the orbiting gear is not restrained radially, it contacts the fixed gear and rolls on its inner surface. A normal force is developed at the contact point between the gears to balance the magnetic attraction and the centrifugal force of the orbiting gear. The friction available due to this normal force increases the transmission’s torque capacity, which is further increased by elimination of the gap between the gears. Also, the radial load on the supporting orbiting gear bearing is eliminated. A prototype with a reduction ratio of 26 is being tested.

Smooth Operation with Manufacture Error and Modification of Cycloidal Pin Gearing

The paper considers the modification or the manufacture error of cycloidal gear, then analyzes the relationship of pin circle meshed with the modified cycloidal gear, discuases the amount of error that leads to destroying conjugate action and results in the changes of tbe instantaneous velocity ratio and so as to affect the smooth operation of cycloidal pin gearing. The idea of the relationship between amount of modification aud manufacture error and the smooth operation can be gotten from the curve diagrams of the instantaneous velocity ratio. Therefore, the directions for improving the reature of the cycloidal pin gear transmission are clear.

Active Design Method of Tooth Profiles for Cycloid Drive Based on Meshing Efficiency

An active design method of tooth profiles for cycloid gears based on their meshing efficiency is proposed.This method takes the meshing efficiency as one of the design variables to determine the tooth profiles.The calculation method for the meshing efficiency of planetary transmission is analyzed and the equation of the meshing efficiency is deduced.Relationships between the meshing efficiency,the radius of the pin wheel and the eccentric distance are revealed.The design constraint quations and the strength constraint quations are deduced.On the basis of this,a design procedure is laid out.Some examples using different input parameters are conducted to demonstrate the feasibility of the approach.A dynamic simulation of the rigid flexible coupling of cycloid gears is also presented.The results show that the proposed design method is more flexible to control the tooth profiles by changing the input values of the transmission efficiency.

A Design of Forming Hods on Machining Corrected Cycloidal Gears

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Cycloid motions of grains in a dust plasma

Hypocycloid and epicycloid motions of irregular grains （pine pollen） are observed for the first time in a dust plasma in a two-dimensional （2D） horizontal plane. These cycloid motions can be regarded as a combination of a primary circle and a secondary circle. An inverse Magnus force originating from the spin of the irregular grain gives rise to the primary circle. Radial confinement resulting from the electrostatic force and the ion drag force, together with inverse Magnus force, plays an important role in the formation of the secondary circle. In addition, the cyclotron radius is seen to change periodically during the cycloid motion. Force analysis and comparison experiments have shown that the cycloid motions are distinctive features of an irregular grain immersed in a plasma.

Non-undercutting condition and parameter optimization for cycloid ball planetary transmission

The transmission performance of cycloid ball planetary transmission(CBPT) is affected by cycloid tooth undercutting directly, and the design of CBPT can be optimized by the non-undercutting condition. Firstly, the theoretical equation of cycloid tooth is given, and the curvature radius of cycloid tooth profile is derived. Secondly, according to the relationship between the curvature radius and the distribution circle of balls, the non-undercutting condition of cycloid tooth profile is established, and the non-undercutting critical condition is deduced. Finally, the validity of the non-undercutting critical condition is verified by simulation. The result shows that the non-undercutting critical condition can be used to optimize the design of CBPT.

Temperature dependent terahertz giant anisotropy and cycloidal spin wave modes in BiFeO3 single crystal

THz time-domain spectroscopy(THz-TDS)is used to study the THz-optical properties of a single crystal bismuth ferrite BiFeO3(BFO).It can be found that the anisotropy of BiFeO3 is strongly dependent on the temperature.A giant birefringence up to around 3.6 is observed at 1 THz.The presence of a spatially modulated cycloidal antiferromagnetic structure leads to spin cycloid resonances(SCR)ψandΦ,corresponding to the out-of-plane and in-plane modes of the spin cycloid,respectively.We distinguish the SCR with respect to their response to orthogonal polarizations of the electric fields of the incident THz beam.In addition,we observe a resonance appearing below 140 K,which might be interpreted as an electromagnon mode and related to a spin reorientation transition.Our present observations present that the temperature and polarization,as the external control parameters,can be used to modulate the THz optical properties of BFO single crystal.

A Numerical Investigation on the Characteristics of the Radial Force in a Cycloid Gerotor Pump

In order to improve the performances of a cycloid gerotor pump,the variations of the radial force induced by different rotating speeds and outlet pressures are analyzed numerically.Using the numerical simulations as a basis,an improved oil inlet and outlet groove structure is proposed.The results show that the radial force decreases with the decrease of the outlet pressure and of the rotor speed.Compared with the original model,the large-end oil inlet line and pressure line of the new oil groove are claw-shaped.This configuration can effectively weaken the pressure changes inside the gerotor pump and reduce accordingly the radial force on the inner rotor.

An Attempt to Evaluate the Cycloidal Rotor Fan Performance

In this work, the cycloidal rotor fan (CRF) performance was estimated by means of a numerical method based on Unsteady Reynolds Averaged Navier-Stokes equations (URANS). The fan with a cycloidal rotor belongs to the positive displacement machines of the rotary type. The numerical algorithm for simulation of the flow in the cycloidal rotor as well as postprocessing of the CFD results was prepared using Ansys CFX CEL. The methodology for the assessment of the CRF performance was proposed and verified. It was found out that the CRF performance strongly depends on the shape of the profile of the applied rotor blade. The NACA 0012 and CLARK Y profiles were tested for the same CRF structure and flow conditions. Also, the crucial importance for the CRF performance has the range of the blade pitch angle change.

The Study on the Cycloids of Moving Loops

The infinite set of cycloids is created. Each cycloid of this set is defined as a movement trajectory of a point when this point circulates on the convex closed contour of arbitrary form when this contour moves rectilinearly without rotation on the plane with a velocity equal to the tangential velocity of a point on circulation contour. The classical cycloid is elements of this set. The differential equation of a cycloid set is derived and its solution in quadratures is received. The inverse problem when for the given cycloid it is necessary to fine the form of a circulation contour is solved. The problem of differential equation of the second order with boundary conditions about a bend of big curvature of an elastic rod of infinite length is solved in quadratures. Geometry of the loop which is formed at such bend is investigated. It is discovered that at movement of an elastic loop on a rod when the form and the size of a loop don’t change, each point of a loop moves on a trajectory which named by us the cycloid and which represents a circumference arch.

Cycloid Motions of Aggregates in a Dust Plasma

Hypocycloid and epicycloid motions of aggregates consisted of one large and one small grains are experimentally observed in an rf dust plasma.The cycloid motions are regarded as combination of a primary circle and a secondary circle.Measurements with high spatiotemporal resolution show that the secondary circle is determined by the initial angle velocity of the dropped aggregate.The primary circle originates from the asymmetry of the aggregate.The small grain in the aggregate always leads the large one as they travelling,which results from the difference of the natural frequency of the two grains.Comparative experiments with regular microspheres show that the cycloid motions are distinctive features of aggregates immersed in a plasma.

Y 7663 CYCLOID GEAR

This machine tool is produced by theQinchuan Machine Tool Works. It isused mainly for grinding cycloid gearsin the cycloidal speed reducer. The toothflank of the gear is the equi-distance curve ofmetamorphic epicycloid. The structural features of the machinetool are: the machine adopts the generatingprinciple for grinding; the table surface isprovided with a V-type circular guideway,so as to guarantee a stable working accuracy;the column unit employs a ballscrew

Preliminary research on cycloid as a line type of the arch dam

Currently, there are a wide range of line types in the field of arch dam designing and construction, and each of them may have their own strength and weakness disparately. A trade-off between the size, stress, as well as the construction cost and complex- ity of the dam needs to be made in order to arrive at a new solution called the cycloid arch dam. Through redevelopment of VBA us- ing AutoCAD, the arch ring and the center of the arch line have been designed. Also, the stress analysis on parabola and cycloid have been done, which provides a theoretical principle that the cycloid could be regarded as a new line type of the arch dam.

Research of the Pressure Angle for Whole Cycloidal Gears

The working profile of whole cycloidal gear is made up of epicycloid and hypocycloid entirely, according to the theory of meshing of gears and the properties of the cycloid, deals with the derivation of the pressure angle formula for the whole cycloidal gear in theory, and reveals changes of the pressure angle of whole cycloidal gear through examples, finds the application relationships between the pressure angle and other design parameters of the whole cycloidal gear, proves the possibility that the whole cycloidal gear can be used in internal parallel move gear mechanism, also provides theoretic fundament for designing internal parallel move whole cycloidal gear correctly.

ERROR PROCESSING METHOD OF CYCLOIDAL GEAR MEASUREMENT USING 3D COORDINATES MEASURING MACHINE

An error processing method is presented based on optimization theory and microcomputer technique which can be successfully used in the cycloidal gear measurement on three dimensional coordinates measuring machine (CMM). In the procedure, the minimum quadratic sum of the normal deviation is used as the object function and the equidistant curve is dealed with instead of the teeth profile. CMM is a high accurate measuring machine which can provide a way to evaluate the accuracy of the cycloidal gear completely.

NO REVERSE ERROR BALL TRANSMISSION AND FORCE ANALYSIS ON HETERO TYPE SINGLE CYCLOID

The construction kinematics and no reverse error property of heterotype single cycloid steel ball transmission are studied and its engagement pairs structure as well as foree analysis are al- so presented. It provides a kind of high property driver of large transmission ratio and compact con- struction and has theoretical and practical significance for application of the steel ball transmission.