THE PRINCIPLE AND APPLICATION ON ZS DYNAMIC BALANCE METHOD OF MACHINE RIGID ROTATOR

In this paper, based on the actual need of production, a new technic method-ZS method on duple fact dynamic balance of machine rigid rotators is presented for small-scale production. The unbalanced weight and direction are obtained by adding duple test weight and measuring the bearing amplitude to the rotator system. The primary principle is developed in detail and the rightness of the new method is proved out by the simulant test and the applied real example. The outstanding advantage of the new method is that the investment cost is low and the adaptability is strong. There is a spacial application value for the great dajority of the mid and small enterprises that produce rotators in small-scale but usually the rotator standards need to be changed.     

DYNAMIC ANALYSIS AND NUMERICAL METHOD IN PHE DRIVE MECHANISMS OF THE STEEL-TUBE COLD-ROLLING MACHINE

In this paper, the calculating formulas for partial dynamic balance of crankslider mechanisms are derived in terms of the limear independent vector theory. The driving torque and the optimum selections for partial dynamic balance in drive mechanism of the steeltube cold-rolling machine are carried out. The method in this paper has a universal reference meaning for the partial dynamic balances of crankslider mechanisms.     

Double-Face Dynamic Balance Method of Spot Rotator without Removing the Test Weights

Site dynamic balance is a important element in installation and maintenance of heavy rotary mechanism. It's hard to discharge testing weights, and the remanent weights will effect the result of balance test. The paper presents a kind of dynamic balance algorithm which need not to discharge the test weights, basing on influence coefficient. The principle of the algorithm is to balance the sum of original unbalance weights and testing weights by the result balance weights. In the algorithm , the influence coefficient of last time can be used optionally for the same rotor. Then developing a dynamic balance system building on it. The site experimental results indicates that this algorithm has a high balance precision, predigests the steps and reduces the operation time.     

A Study on Theory and Application of Automatic Balance for Rotors

The study on automatic balance of the rotor was made both from theory and ap-plication.In the light of the feature of automatic balancing,new analysis about the mechanical modelof vibratory system was done,and the result is that the accurate model of system can be gained bycompensation method and the traditional principle errors of balance machine both for soft and hardbearing can be overcome.The autornatic balance testing theory was proposed.The automatic balancesystem has been developed a nd the fu n ction a nd techn ical key are also discussed in detail.     

A NEW METHOD BY USING MASS AND ACCELERATION PARAMETERS FOR BALANCING INERTIAL FORCE OF MECHANISM

This paper presents a new method by using mass and acceleration parameters for balancing inertial force of mechanism. Compared with other balance methods, this one is simple, clear and superior in regularity when the balancing equation of complex mechanism is established, and its solving procedure is also easy. The new methcd is convenient to learn and use as well as convenient to program.     

Embedded Intellingent Dynamic Balance Testing System and Its Digital Filter Designing

A lot of information needs processing in time in dynamic balance testing, but the current intelligent dynamic balance instruments and the controlling box of dynamic balance machines made up ofsinglemicrocontroller do not meet the request.A method isgioen that the DSP-Microcontroller will be useddiredtlyinthe system of the intelligent dynamic balance instrumentby using embedded design technique. A principal and subordinate control system compose of DSP and microcontroller. The Microcontroller the system as a principal controller and the DSP implements digital filtering and FFT in dynamic balanc by means of its fast operation. The system develoyed according tothe method can do more analysisin time areaand frequency area.     

Dynamic optimization design of gear transmission system for wind turbine

The differential equation which governs the behavior of the gear transmission system of 1.5 MW wind turbine is established. The external excitation caused by wind speed fluctuation is discussed and the internal excitation due to time varying mesh stiffness and comprehensive error is also analyzed. The calculating formulations of the harmonic balance method of nonlinear dynamic equations are presented. Then, the multi objective dynamic optimization model is developed to minimize the value of vibration acceleration and the overall volume. The optimization of a practical example using mixed discrete combined programming is performed. The result shows that the proposed method of modeling and optimization design can effectively reduce the wind turbines gearbox vibration levels and weight.     

ENERGY BALANCE OF HYDRAULIC FRACTURE AND FRACTURE TOUGHNESS

Based on the discussion of the phenomenon that the effect of fracture toughness is neglected in general hydraulic fracturing models, this paper gives the energy balance equation in-colding all parameters in hydraulic fracturing and proposes a method of determining the apparent fracture toughness of rock from hydraulic fracture experimental data. The discussion on the factors affecting apparent toughness indicates the inevitability that the apparent fracture toughness of rock measured by hydraulic fracture experimental data is significantly higher than that measured by the standard three-point bending method.     

纤维素酶对草鱼生长性能和饲料消化率及体成分的影响

选用120尾当年鱼种(初始体重47.8g左右)，随机分为四组（即对照组、I组、II组、III组，每组30尾）在水族箱中进行饲养。对照组饲喂基础饲料，I组饲喂基础日粮+0.05%纤维素酶，II组饲喂基础饲料+0.1%纤维素酶，III组饲喂基础日粮+0.2%纤维素酶，每天投喂4次,试验期共饲养49d，探讨外源性纤维素酶对草鱼生长性能、饲料消化率和体成分的影响。结果表明:饲料中添加纤维素酶，草鱼增重率提高，饵料系数降低；干物质、粗蛋白、粗脂肪和粗纤维消化率都提高；体成分没有显著变化。     

A charge balance control algorithm of dual-transistors forward converter

An algorithm is proposed for dual-transistors forward converter (DTFC) by using the principle of charge balance control during a transient process to improve their dynamic performance. Combined with response curve,the theoretical analysis and some key equations are presented to improve the dynamic performance of the DTFC by minimizing the over/under shoot and the recovery time. In order to avoid the magnetic saturation of the transformer,an approximate method is introduced in the calculation of the optimal switching time,which can also be applied to other isolated converters when the maximum duty cycle is limited. Finally,the simulation results and the experimental results of the prototype show that,compared with the traditional voltage mode control,the proposed algorithm can significantly improve the dynamic performance of DTFCs.     

THE NEW METHOD-QL SYSTEM FOR MEASURING DYNAMIC ACCURACY OF THE DRIVETRAIN

The paper introduces a new method-QL system suggested for the first time by the author for measuring dynamic accuracy of gear cutting machine drivetrain. The system has many uses. It suits not only the measurement of mid-size machine tool but also the measurement of very slow speed, large ratio, large-size machine drivetrain     

东北玉米通风调质试验

东北地区储粮粮堆由于气候原因存在一个巨大的"冷心",冷心的主要应用方式为膜下环流均温控制和缓式通风上调冷心控粮温,这两种方式都是利用冷资源进行的粮温控制。而目前的粮堆增湿方式主要为湿膜机增湿和各种调质机增湿,利用"冷心"增湿还没有成功的案例。利用冷心增湿,内结露现象很严重,而且容易出现局部水分偏高现象,且违反机械通风操作规程1。但通过缓式通风的精确掌握和粮堆增湿理论的精确控制,大胆试验,事实证明冷心内结露增湿方式是可行的。试验将出仓前平均水分13.5%提高到最高14.8%,平均水分14.1%,达到试验预期目的。试验仓出仓验证实际增量21.05t,效益十分可观。     

Applying hybrid dynamic substructure synthetic method to dynamic analysis for tower crane

This paper presents a dynamic hybrid substructure synthetic method for tower crane dynamic analysis. This method employs the transfer matrix method and the flexibility degree method respectively to formulate the vibration mathematical models of the tower body and tower top system substructures in the hoisting luffing plane. Based on the motion of the substructures in the interface and the dynamic harmonize condition, the frequency equations are established. Then the program is designed according to the mathematical models and firstly applied to the dynamic analysis of the QTZ63 tower crane in the construction site and the parameter identification of attached device and tower body. The test results show that the value calculated by the above method is quite approximate to the instrument measured value, which can meet the engineering requirements. Further study has found that , for the flexible long-distance attached tower crane, the method that introduces dynamic load coefficient for statics analysis of tower cranes is unprecise enough since there exist errors.This paper suggests to conduct site test and identification of the rigidity coefficient of attached device of the tower crane for the accident prevention of tower crane collapse by timely take measures.     

The Basic Element Method of Recogniting Handwritten Mathematical Symbols

An on-line recognition approach for the handwritten mathematical symbols is presented. Firstly, it analyses the structures of 94 commonly used mathematical symbols and concludes that all of them consist of 10 basic elements. Secondly, it proposes a new method of basic element ordering and reduces the number of standard symbols by extracting three primary features of mathematical symbols,namely,basic element vector, relative positions between basic elements,and basic element length vector. Finally, the traditional dynamic programming method is improved by considering matching and unmatching value and adding geometric restraints.Through improved Kohn-Munkres algorithm. During the recognition test of mathematical symbols handwritten by 20 subjects, correctness rate reaches 92.52%,incorrectness rate 3.03% and refusal rate 4.45%.     

Method of Measuring Rotational Speed for a High-speed Rotator Dynamic-balancing Testing System Based on DSP

The device of testing rotational speed is very important to dynamic-balancing testing system.Requirements for the device of testing rotational speed include: high-accuracy,stabilization,credibility,and shorter testing time.To the development of high-speed rotor dynamic-balancing testing system based on DSP(digital signal processing),the way of picking-up rotator reference signal,testing rotator speed based on DSP and the design of software are introduced.This new way of testing rotational speed in high-speed rotor dynamic-balancing testing system based on DSP is accurate,simple,convenient,the range of rotational speed which can test is broad,and the new way is very suitable to pick-up the amplitude and phase of vibration caused by unbalanced amount.     

A NEW METHOD BY USE OF MASS AND ACCELARATION PARAMETERS FOR BALANCING THE SHAKING MOMENT OF ARTICULATED MULTI-BAR LINKAGES

In this paper,a new method with general purpose ispresented for balancing the shaking moment of articulated multi-barlinkage.The concept of this method is clear.The moment equation oflinkages is easy to establish and solve.Furthermore its pattern structuremakes it convenient to be programmed.     

The on-Line Identifying Method for the Dynamic Unbalance of the Rigid Rotator

The basic principles of the on-line identifying method for the dynamic unbalance of rigid rotators were discussed. The influent coefficient matrix was proposed to calculate the unbalance,and the matrix elements were obtained by adding the trial weight. The identifying accuracy was verified by simulation tests. Finally, discussed the schemes of the software and hardware of the on-line identification.     

Design fuzzy membership functions based on the posterior probability weighting

The determination of fuzzy membership function in the fuzzy support vector machine (FSVM) is a difficult problem. To solve the problem of being sensitive to the noises and outliers in support vector machine, by the inspiration of Bayesian decision theory, combining with sample density characteristics, sample points relation between same class and other class is researched, and the tightness on each sample points is described. Based on that, method of posterior probability and sample density weight are given to each sample, and new fuzzy membership function is proposed. The detection of the noises and outliers is avoided by this method. Numerical simulation shows that the improved fuzzy membership function method is effective.     

A NEW APPROACH OF LOAD FREQUENCY DECENTRALIZED CONTROL-OPTIMIZATION OF WEIGHT MATRIX Q

As the optimization and coordination of weight matrix Q and feedback gain matrix K are taken into account, the dynamic performance of the decentralized controller designed by this method is as good as that of the optimal controller. This method can be used in the strong or weak coupled systems, and various controllers can be designed according to the demand. An example is given to prove the validity and advantage of this method.     

THE RESEARCH OF MONITORING AND DIAGNOSING BALL BEARING FATIQUE ON LINE

This paper describes the research work of analyzing vibration signal to monitor and diagnose on line the ball bearing fatique. Carrying out a large mumber of life test on ball bearing test machine, it is discovered that in the so called "second effect" vibration signal as the bearing fatique occurs, apart from the two widely used spetrum charactersof "fraverse frequency" and "high frequency shock pulse" , there is another important but rarely known opcctrum characteristic of high frequency peaks existing in the middle-to-high frequency band.The generating mechanism, effect factors and test method of those high frequency peaks are researched tentativ tentatively. Two binds of device for monitoring abnd diagnos sing ball learing fatique on line are developed based ion this new type spectrum characteristic. One consists of a bandpass filter, the other is based on the spetrum characters which corns from the DDS ( Dynamic Data System ) modeling