Abstract:A kind of similar ruled surface integral impeller flank milling machining method was proposed based on inspection at original position. Firstly，the similar ruled surface was reconstructed for approximate ruled surface；then the similar ruled surface integral impeller flank milling judge conditions were proposed. For tool axial vector solved question of nondevelopment ruled surface，analytical method was proposed. Finally similar ruled surface tool path simulation and actual numerical control (NC) machining experiments were carried out, which verify the correctness of the algorithm.

Abstract:According to the principle of bladder power pump driven by ultrasonicvaporized steam, the urethral valve using rubber was designed, the structure parameter of urethral valve was determined. The mathematical models of driving force and urine flow rate of urethral valve were built based on the theories of ultrasonics and thermodynamics, and the effectiveness was verified by simulation and experiment. The 3D solid model of urethral valve was established and the opening size and shape of urethral valve under the different materials match and driving force direction was simulated using ANSYS Workbench. The effect of the opening size of urethral valve on urine flow rate was studied by experiment. The results show that the urethral valve can meet the functional requirements. The research findings can provide basis for the design and the study of urethral valve, which can also provide reference for the design of other implantable devices of human.

Abstract:Due to the processing, installation and wear, clearance exists inevitably in the hinge of the electrohydraulic control mechanism of large scale wind turbine variant pitch control system. Oversize clearance would expand the overshoot and bring overmuch shock during selftuning, even cause resonance of the vane and the tower and result in wind turbine outage accidents ultimately. Formed mechanism of the clearance existed in the hinge of wind turbine variant pitch control mechanism was analyzed, a compensation method was proposed for clearance with using Fuzzy selftuning proportion integral differential （PID） control algorithm. According to impactvibration model of clearance to formulate fuzzy reasoning rule, the parameter selfadaptive adjustment of PID controller was implemented. When the clearance was 02, 04, 06 and 08 mm in part, the conventional PID controller and the fuzzy selftuning PID control performance were studied and compared. The result is that as compared to the conventional PID controller, the fuzzy selftuning PID controller can reduce overshoot and shock time of the large scale wind turbine variant pitch control system obviously and avoid the impact of wind turbine variable pitch effectively.

Abstract:In order to solve the problems of the complexity of parts measurement in CMM at present, a technology of CMM measurement based on three dimensional (3D) printing was proposed. In order to make sure the products could be measured in A0B0 which was the highest precision direction of CMM probe, auxiliary jig was often needed. Firstly, the optical scanning technology was used to obtain the product surface datas. Then data were processed in Geomagic Studio software. The mesh face was imported into the Rapidform software to model and design the product jig. And the designed final model was imported into 3D printer to gain the jig model. Finally, the product was placed in the jig to be measured. The test has proven that the efficiency of complex parts measurement with CMM is improved using this method.

Abstract:Micro vibration of the aerostatic guide way has a significant impact on its dynamic characteristics and stability, which limits the development of pneumatic component. High pressure gas molecules collide with the supporting surface and the internal surface of the throttle during the flow process. Variable impulse of the surfaces aside for the gas film are affected by the changes of impulse which formed irregular impact force in horizontal and vertical direction. Microvibration takes place based on the natural frequency of the system and its frequency doubling. The vibration model was established to describe the dynamic characteristics of the gas film. By comparing computational results and experimental data, formation mechanism of the micro vibration in the gas film was confirmed. The result shows that the micro vibration of gas film can be produced no matter whether there is a gas chamber or not in the throttle. Meanwhile, The micro vibration of the guide way with air chamber is greater than that without any chamber under the same conditions. The frequency points of the vibration peaks are almost the same, as well as the vibration pattern in the frequency domain.

Abstract:The simulation analysis was made and the experimental verification was carried on the hydromechanical continuously variable transmission of the high clearance self propelled sprayer vehicles of indigenous design. The results show that engine speed, flow of speed control valves, pressure of main circuit and load torque are the main factors to influence the shift quality. Adopting the lower speed of engine，the lower pressure，the smaller load torque，and the larger flow can improve the shift quality as soon as possible. Agricultural spraying vehicles equipped hydromechanical transmission can not only achieve a continuous stepless change in speed, but also easy in operation, and reducing the labor intensity of the driver.

Abstract:Taking the HJ044 dual rotary table fiveaxis numercial control (NC) machine tool as an example, using the builtin sensor information of machine tool and the theory of multibody system as basis, and built kinematics modeling of tools related to parts, a dynamic machining error online monitoring method of NC machine tool based on buildin sensors was put forward. The method was directly used of the machine tool encoders or grating ruler of builtin sensor for information acquisition such as machine tool all axis motion displacement, and combined with kinematics model of the machine to measure machining error induced by dynamic charaateristics of the machine tool. The experiment shows that this method is an effective and simple dynamic machinining error onling monitoring and measuring method of NC machine tool.

Abstract:or the bad working environment of the subsea collect connectors, lots of external interference factors and being subject to tension, compression, bending, twisting or other external forces, the model of connector has been built. Various stress states were analyzed, and method of calculating maximum bearing capacity was proposed under all the states of connectors. The bearing capacity of tension of the connector was analyzed by the determination of dangerous cross section and elongation of the collect. The bearing capacity of compression was depended on the reserved distance of two flanges, and was analyzed by calculating the largest amount of compression of the collect. The bearing capacity of bending moment was pivoted to the force of the collect which was furthest from the center line of flange, and was analyzed according to the theory of overturning moment. The bearing capacity of torque was depended on the friction force between flange and collect, and it was different in different working conditions according to the change of the normal force that from collect to flange. The method of analysis of bearing capacity by analyzing the stress state of connector is a good reference for development of domestic similar subsea mechanical connectors.

Abstract:There is important significance of air cushion performance for the working state and service life of cylinders. While the change of any work condition may damage adjusted air cushion thus influence the smooth process of fatigue test. So its necessary to master the relationship between all test factors and air cushion performance. Considering the particularity of fatigue test, the experiment should be designed under a premise that the cylinder structure keeps undestroyed. Load quality, opening of cushion needle value and velocity regulation valve as the unit factor variable were set respectively, then the displacement curve of the load was tested under different conditions, and by analyzing the displacement curve and velocity curve, the rebound amount and the residual kinetic energy at the end of the air cushion stroke were obtained to show the rebound strength and impact strength of the piston. The influence of various factors on the effect of the air cushion is elucidated.

Abstract:Based on the computation of flank milling, an approach was proposed to determine whether complex surfaces could be manufactured by flank milling. The proposed method was suitable for flank milling of any ruled or nonruled surfaces. The flank milling error was computed by the signed distance between the design surface and the envelope surface. On this basis, the maximum error for the optimum tool path was applied as the flank milling condition to satisfy the machining accuracy requirement. The numerical examples indicate that the proposed method can determine whether the tool path is suitable for flank milling of impeller blades, and simultaneously the optimum tool path can be generated. The experiments show that the machining efficiency can be greatly improved.

Abstract:For the merit of highspeed onoff valve which are accurate control flow, low price, strong antipollution, high repeatable accuracy and good stability, the idea of using highspeed onoff valve instead of servo valve in automatic gauge control (AGC) system of rolling mill was presented. The highspeed onoff valve position control mathematic model was established based on pulse width modulation（PWM） control method of linear transformation of duty ratio in automatic gain control (AGC) hydraulic system, and its response curve of displacement, flow and rolling force were analyzed in the Simulink software when the cylinder had downward movement. The research results show that the high speed onoff valve can realize fast and accurate control of the cylinder block in AGC system, and the idea of using it instead of servo valve in AGC system is feasible.

Abstract:Gas flow field of the bearing usually has a large diameter ratio about four orders of magnitude or above. The simulate operation of gas bearing become very difficult.Through the analysis of traditional model of gas bearing, new type of surface gas bearing was proposed.The numerical simulation model was established and surface type gas bearing with straddletype gas bearing loadbearing characteristics were analyzed. With the help of FLUENT and parametric design function DX module, the numerical simulation precision of this kind of problem solution was put forward. Use above method, numerical stability under the dimensions of discretization model file was obtained. And the simulation research of the surface gas bearing was conducted by using this file. The result shows that the new method of grid independence of numerical simulation is helpful to improve the precision of the numerical simulation, the loadbearing characteristics of surface air support structure is more compact than straddle support structure.

Abstract:In the process of actual wheelset assembly, in order to eliminate the influence of a series of factors on the accuracy of the cylinder force dispalyed, making sure the cylinder pressure value is accurate. The error of the cylinder pressure displayed in the interface of control software was analyzed in detail. The method of quadratic curve fitting and its practical application in pressure calibration were introduced. The pressure error values of cylinder pressure before and after calibration were compared. The results show that the validity of the application of quadratic curve fitting method in pressure calibration of cylinder is effectively improved. 

Abstract:In order to improve the vibration performance of a vehicle, the twoaxis interconnected hydropneumatic suspension system on same side was proposed. The mathematic model of the hydropneumatic suspension system was built based on its structures and working principles. The characteristics of rigid force and damping force for the suspension system were investigated, the connectivity of the suspension system was analyzed, and the effects of system parameters on the performance were studied. The response mechanism of excitation for the suspension system was studied. The results show that the vibration stability of the twoaxis interconnected hydropneumatic suspension system on same side is better than normal hydropneumatic suspension system, and can recovery equilibrium state faster, so its more conducive to rapid through complex pavements. The damping force is unconnected and determined by many factors. The frequency of the excitation mainly influences the damping force and the phase difference mainly affects the rigid force of the suspension.

Abstract:After studying the working principle of the typical pressure roller mills main working principle, buffering process for the hydraulic system was analyzed in theory, and the simulation model was built in AMESim. The relationship between the accumulators inflation pressure and the systems holding pressure & the pistons displacement was mainly analyzed, and the influence of the change in materials thickness on the systems holding pressure & the pistons displacement was analyzed. The result shows that with higher accumulators volume, the smaller pressure fluctuation of the hydraulic pressure, when the volume of the accumulator is up to 30 L, theres no obvious improvement of the buffering; the diameter of the pipeline is positively correlated with the effect of buffering, the diameter of the pipeline should better be more than 18 mm; the bigger of the accumulators air inflation pressure, the better of the capacity of the systems holding pressure, but higher air inflation pressure will results in the obvious vibration of the piston; the increase of the materials thickness will result in the increase of both the vibration amplitude of the piston & the hydraulic cylinders peak pressure.

Abstract:Flow is one of the important parameters of calibration instrument of blood purification device, but the measuring range of existing liquid flow standard devices can not meet the traceability needs of flow in calibration instrument of blood purification device. In order to solve this problem, a small flow standard device suitable for calibration instrument of blood purification device is developed. The piston metering system, combining grating servo feedback and automatic control technology were adopted to realize automatic measurement of small liquid flow. According to the experiment, the measuring range of this device is (10~2 000) mL/min, the maximum permissible error is ±034%, and the repeatability is better than 006%. Therefore, the device fully satisfies the flow traceability requirement of calibration instrument of blood purification device.

Abstract:In order to research the relationship between the breaking torque, locking torque and pretightening force of hilock bolt connection. The mathematical model of high lock bolt connection was deduced with the help of the common bolt connecting classical theory. With the material A286 of the M5, M6, M8 three point hilock nut and non selflocking hilock nut and hilock bolt as the experimental object,the breaking torque, locking torque and pretightening force were got using torsion testing machine. The torque coefficient was calculated by the mathematical model of the deduction. Experimental results show that breaking torque and torque coefficient of the three point hilock nut and non selflocking hilock nut are almost the same. For three point hilock nut, nosing parts almost have no effect on breaking torque of hilock nut, locking torque is linear superposition to breaking torque. The correctness of the mathematical model is verified by the experimental results.

Abstract:In order to enhance the output pressure of the piezoelectric pump, combined with the working characteristics of multichamber in series connection pump, using an umbrellashaped checkvalve, a stacked in series connection fourchamber piezoelectric pump was designed. The design had compact pump in structure, shorter flow channels inside the chamber, smaller geometry volume, and other advantages. The output flowrate and pressure of the in series connection fourchamber piezoelectric pump were tested by drived under piezoelectric vibrators of different numbers. The results show that the output flowrate drived by multipiezoelectric vibrators is about times as much as drived by sigle piezoelectric vibrator (n is the number of vibrators). When driven by 2 or 3 vibrators, the output pressure is about times. When powered by 110 V AC drive voltage, the maximal output flowrate and pressure of the designed pump are 980 mL/min and 123 kPa respectively.

Abstract:In order to meet the design needs of gear pairs with undercut in external gear pumps,based on the machining principle of gear hobbing, from creating a calculation radius formula of gear undercut circle, a complete set of calculation formula of spur gear contact ratio factor suitable for gear pairs with undercutis derived. Based on this formula, the influence of gear basic parameters to the spur gear contact ratio factor with undercut was analyzed; finally, all theobtainedresults wereverified by threedimension (3D)virtual model of spur gear pairs with undercut. The results show that, because of the gear undercut, the apex of driving gear tooth maybe excluded from being meshed, the common calculation method of spur gear apex contact ratio factor instead of spur gear undercut contact ratio factoris not reliable at present.The spur gear undercut contact ratio factor alwaysis affected bygear basic parametersexcept gear module, among them, the influence of gear modification coefficient is the largest. Spur gear undercut contact ratio factor canbeensuredto equal to spur gear apex contact ratio factor by employing the best rack tool tipradius.When the actual spur gear undercut contact ratio factoris too large,the transmission quality of gear pairs was improved by reducing the rack tool tipradius,and etc. It is concluded that a new method for the other conventional undercutgear pairs designis providedby the complete calculation formula of spur gear undercut contact ratio factor.

Abstract:An exact algorithm of relationship of handle steering angle and contact displacement of depressurized pilot valve was proposed. As compared with the method for approximately calculating the displacement of the contact with the linear formula at present, it was found that, in the small angle range, the actual displacement of the contact was basically equal to the linear calculation, but after the angle become larger, and the error was bigger and bigger. The threedimensional (3D) model of pilot valve was established with SolidWorks, and the correctness of the exact algorithm was verified by simulations. In order to improve the fine tuning control performance of the depressurized pilot valve, by optimized the structure of platen of pilot valve, the error caused by handle steering angle becoming large is compensated, and the linear range of use of the handle steering angle is increased.

Abstract:Tensile property of optical fiber cable is an important factor which can affect the quality of optical fiber communication. According to the test requirements of an institute for the equipment, a wheel winding test equipmentis developed to test tensile property of optical fiber cable.Test principle and constitution of the equipment were firstly introduced. Then mechanical structure, controlandtest subsystem and software of the equipmentand other functional moduleswere studiedin detail.Afterwards a tensile property experiment of a 025 mm2cross section area ofoptical fiber cable was successfully performed with the equipment.Study shows that tensile property parameters (load, displacement, extension, strain, stress, and etc.) can be automatically tested with good accuracy and stabilityby the equipment, and six relation curves (loadextension, loaddisplacement, loadtime, extensiontime, displacementtime and stressstrain) can be dynamically drawn timely. The test equipment has been used in an institute and met allthe requirements of testing optical fiber cable well.

Abstract:In order to solve the problem of CNC programming in manifold block, the method of automatically programming was proposed based on Edgecam. The method of processes planning, machining feature recognition and CAM operation construction were studied, the rapid programming system was designed with VBNET and such redevelopment tools as PCI，PDI in Edgecam. Finally, the effectiveness of the proposed method is validated by the case, which provides reference for post processing in other machine tool.

Abstract:The rotary table with high precision is an important indispensable part of numercial control (NC) machine tool, and a rotary table with a fixed angle translocation of 180° is needed in some occasions. A gearrack transmission rotary table eliminating clearance automatically was designed driven by hydraulic cylinder. The main parts included in the table were working table, machine box, uplift drive mechanism, slewing drive mechanism, and eliminating clearance mechanism, and etc. The fixed angle translocation was realized eliminating clearance automatically. It can obtain large transmitted torque with simple mechanism and high transmission precision.

Abstract:Online detection and grouping of the tapered roller grinding ball surface need to achieve higher accuracy and faster speed. According to its technical requirements and characteristics, three coordinates measuring principle was adopted to improve the accuracy of measurement. The multiple triggering of probe was used to measure the same workpiece at the same time to realize the measurement speedup. According to the coordinates of all probe head fitting the spherical ball surface, and then by measuring software to calculate the radius of curvature of ball surface and relative to the outer circular pulses, at the same time grouping according to calculated data, the basis was provided for the assembly process of the bearing. The final assembly accuracy and speed of bearings are improved.

Abstract:The numerical control punch CAM system was proposed which included continuous steppunching processing template customization based on transformation and upgrade of punchand software development of computer aided programming and code automatically generated for the shortcomings of complex hole coordinates calculation, single processing template, low programming efficiency in the processing code compilation of early CNC punch. The upgrade process of the CNC punch,standard and application of continuous steppunching processing template,interaction design method of CNC precision machining contour based on CAXA platform were introduced. Processing code automatically generated software and processing track dynamic simulation software based on VBNET were designed.The application results show that the CAM system is an important part of the numerical control punch high efficiency and automation which avoided a large amount of calculations in the manual programming,greatly improved the CNC punching working efficiency and implemented quickly continuous steppunching processing of profiled holes and profiled outline.

Abstract:To fill the blank about the dynamic performance test equipment of the largescaled damper in nuclear power plant, to solve the bottle neck problem of dynamic performance research about dampers, to provide protection for largescaleddamper on domestic manufacturing and autonomous maintenance inservice, adynamic performance test bench was designed, the test bench had dualpower head, hydraulicdrive system, a plurality of detection sensors, full digital control and other characteristics, and can provide fullload, fullfrequency, continuous online, imitation test for the damper. The test results show the test bench can fully meet the dynamic performance experimental requirements for the largescaled damper in nuclear power plant.

Abstract:In order to ensure that the emulsion concentration keep steady in the emulsion proportioning system, a set of mine emulsion concentration automatic proportioning system control of fuzzy adaptive PID control strategy was designed based on the analysis of ratio of emulsion automatic control principle, and the field measurement was carried out. From two aspects of emulsion flow transient smaller and larger were measured, it was verified that the design of fuzzy adaptive PID control was accuracy. The result shows that the concentration of fuzzy adaptive PID has faster response, smaller overshoot and faster to reach steady state, and the advantages of stronger antiinterference ability, which can realize the optimum control for mine emulsion automatic proportioning system concentration.

Abstract:The reason of partial loaded in cylinder stretching on concrete pump truck boom cylinder was found through experiment and analysis. A scheme to enhance the resist ability in concrete pump truck boom cylinder was put forword. A new kind of guide structure was designed.The anti deflection load of oil cylinder is improved, which povides a refer for further optimize the superlong boom cylinder.

Abstract:In order to analyze the hydraulic system of the concrete pump trucks arm, it is necessary to model and simulate the load sensitive proportional multiway valve of the key components of the hydraulic system. Its dynamic characteristics were analyzed and obtained. According to the working principle of the load sensitive proportional multiway valve used in the hydraulic system, through multidisciplinary modeling, simulation, analysis software SimulationX, simulation model of the valve was established, and dynamic simulation was carried out. The results indicate that this valve is in accordance with practical operating conditions, and modeling method is simple.

Abstract:The simulation model of urethral valve was established based on Fluent software, the driving pressure in the urethral valve was numerically simulated using the computational model of turbulent κ-ε, and the influence of the structure and ultrasonic controlling parameters of urethral valve on the driving performance was analyzed. The results show that the opening time of urethral valve is shortened and the driving performance of urethral valve is improved by reducing the volume of driving cavity, increasing ultrasonic intensity, radiation area and frequency. The simulation model is effective and practical, which can provide the theoretical guidance for the driving performance analysis and optimization design of urethra valve. 

Abstract:The design of valve controlled cylinder type hydraulic elevator adopts the style of pushing up straightly. Regarding the valve controlled cylinder type hydraulic elevator as the research object, its physical model and the dynamic equation of the valve controlled hydraulic elevator system were established based on the piston cylinder and the car frame (m1), the car and the lift truck (m2) two degrees of freedom. On the basis, the calculation method of the natural frequency of the vibration of the hydraulic elevator system was discussed. Through the simulation experiment, the influence of the oil liquid rigidity, the rigidity of axle rubber damping pad and the change of the cars cabin of load size on the natural frequency of the system was emphatically analyzed. The results show in other conditions unchanged, first or second order natural frequency of the hydraulic elevator system decreases with the decreasing of the oil rigidity. First or second order natural frequency of the hydraulic elevator system increases with the increasing of the rigidity of rubber damping pad under the car axle. First or second order natural frequency of the hydraulic elevator system decreases with the increasing of the cars cabin of load size.

Abstract:A new type of electro hydrostatic actuator brake system was presented, which was based on the analysis of the structure of electro hydrostatic actuator brake system and the application of electro hydrostatic actuator technology in aircraft steering gear. And the two kinds of electro hydrostatic brake system were analyzed. The simulation results show that the dynamic performance and braking efficiency of the optimized Electro Hydrostatic Actuator brake system can meet the requirements of the brake system, and its dynamic performance frequency is higher than that of the former.

Abstract:Nonlinear finite element model (FEM) of NGW type planetary gear train of input stage transmission mechanism used in wind turbine boxes was established according to the nonlinear contact theory and finite element theory, for difference analysis of transient meshing characteristics of planetary gear pair between mating and nonmating surfaces. Transient meshing process of the gear pair was studied in dynamics experiments. The timehistory curve of stress of meshing tooth profile at different position was obtained for components of the gear train． The study results show that different position of meshing tooth profiles have similar stress variation history． The stress of internal planetary gear is bigger than that of the external planetary gear． On the basis of FEM, the comparison and analysis are carried out to find out the effect of some key working parameters on the transient contact of the mating surface and nonmating surface of the planetary gear pair, which provide instruction basis of transient optimal design for improving the meshing perofomance and reliability of a planetary gearing system．

Abstract:To reduce the influence of gravity disturbance torque on the balance and simulation accuracy of the three axis airbearing testbed, the calculation method for unbalance torque raise by gravity gradient of airbearing testbed was presented. According to the existing slightly difference by gravity on each particle of the platform, the computational model of unbalanced torque caused by gravity gradient was established and the influence of gravity gradient unbalance torque on the equilibrium of airbearing testbed was analyzed. The simulation results show that the gravity gradient unbalanced torque is the sine function as two times tilt angle of the platform. With the mass center approaching to rotation center, the gravity gradient unbalance torque is gradually becoming the main factor affecting the airbearing platform balance.

Abstract:As to the problem that special tools variety and knifeedge are very difficult to work out by normal tool grinder and traditional production technics, a kind of selfdeveloped fiveaxis CNC tool grinder was created. What’s more, the performance of grinder was affected by the stress and deformation of linear feed system. The stress and deformation of linear feed system were analyzed by Solidworks Simulation. The results show that the maximum stress of the Xaxis worktable is 2 MPa, which appears on the lower part of the slider and the column of Xaxis table, and the maximum displacement of the Xaxis worktable is 0000 015 88 mm, which appears in the middle of the column. On the Yaxis workbench, the maximum stress is 2 MPa, which appears in the middle of the Yaxis table, and the maximum displacement of the Yaxis table is 0000 003 584 mm, which appears in the middle of the Yaxis table; On the Zaxis workbench, the maximum stress is 103 MPa, which appears on the right side of the Zaxis table, and the maximum displacement of the Zaxis table is 0000 030 88 mm, which appears in the middle of the Zaxis table.

Abstract:Larger power of armored vehicle cooling system was focused on. For needs of higher fan speed control and effective energy saving, the basic compositions and principles of armored vehicle hydraulic driven fan system were expounded, and the systematic mathematical model was established. Based on the simulation analysis which carried out on the different performance parameters system, such as motor displacement, the total volume system and so on, the influence laws to the performance parameters of dynamic characteristics of hydraulic drive fan system are introduced, which provide the theoretical guidance for the optimization design of the system.

Abstract:The issue of screwin cartridge counterbalance valve was studied, and the influence on stability of hydraulic balance circuit in the process of lifting of the roadheader cutting part by structural parameters of the valve was analyzed. The static equation of cutting section was established, and then the load of the cylinder was simulated. The dynamic process of the counterbalance valve was simulated by using AMESim, and the test rig was built to test the dynamic performance of the valve. The internal flow field of the balance valve was simulated by use of the FLUENT. The results show that the load of cylinder is decreased gradually with the cutting head rise. Dynamic performance simulation and test results are basically consistent. The smaller the load of the oil cylinder, the damping hole and the spring pretightening force, and the greater the spring coefficient, the more favorable is to the stability of the system. A Smaller mouth opening and a larger conical angle of valve spool are favorable to reduce and avoid happening of phenomena of air erosion and low frequency twittering.

Abstract:Aiming at a new type of sucker rod damper, a mathematical model of damping force was established, and based on ANSYS CFX and fluid dynamic theory simulation, the effect rule of damping aperture size and annular gap height on the damping force was systematically studied. The results show that when the d0=1 mm,h=03 mm, the maximum damping force is 1431 kN, and when the d0=4 mm,h=05 mm, the minimum damping force is 85 kN; with the increase of the damping aperture and annular gap radial height, the damping force decreases; When the damping aperture is small, the effect of the annular gap height on the damping force is obvious, and when the damping aperture is more than 3 mm, the effect is gradually decreased; When the annular gap height is small, the effect of the damping aperture on the damping force is obvious, and when the annular gap height is more than 04 mm, the effect is also gradually decreased.

Abstract:With considering the oil film bearing in rolling mill as the research object, the various factors that cause the failure were comprehensively analysed, and the oil film bearing in rolling mill failure of fault tree was established. Through quantitative analysis of the fault tree, the oil film bearing of each stage of minimal cut sets was solved, and sleeve damage, liner damage, lubricating oil deterioration as the main failure form of oil film bearing in rolling mill was determined. The relevant measures of preventing oil film bearing in rolling mill failures and improving its reliability are proposed.

Abstract:Aiming at spare parts ordering problem for the key equipment system which degradation state distribution function is unknown,a kind of spare parts order decision optimization method which considered withcombining offailure prediction results and spare parts ordering was presented based on failure prediction.Firstly, according to the remaining life prediction results which obtained by detecting state information, the residual life of spare parts orderingwas taken as threshold to draft spares ordering decision strategy.Then, according to the theory of renewal process, the prescriptive availabilitywas selected as constraint, the expected cost per unit time was identified asoptimization goal to establish the optimization modelwhose optimization variableswere failure prediction intervals and sparepartsordering threshold.Then, according to the theory of renewal process, the prescriptive availabilitywas selected as constraint, the expected cost per unit time was identified asoptimization goal to establish the optimization modelwhose optimization variableswere failureprediction intervals and sparepartsordering threshold.Finally, the example is given to solve simulation and optimizationof the established model to obtainthe bestfailure prediction intervals and sparepartsordering threshold, which verifies the feasibility and effectiveness of the model.

Abstract:The working principle of a loader hydraulic system was analyzed. On the basis of establishment of loader hydraulic system fault tree, modern testing techniques were used for loader hydraulic system operating parameters online monitoring, and PHP and MYSQL development technology were used to design loaders humancomputer interaction fault diagnosis expert system. Through the design of wireless network interface, the Socket transmission of monitoring system and expert system information was realized. When a failure occurs in the course of the loader, through the fault analysis of external performance and monitoring parameters online, the application of expert system can eliminate and solve problems quickly.

Abstract:Chatter in the process of end milling would lead to poor surface finish, low material removal rate, severe tool wearand noisy workplace, and etc.Chatter vibration can be detected by most chatter detection system, however, it already has serous effects on the surface quality of workpieces as well as the cutting tools when it occurring.Therefore, chatter detection system must find chatter characteristicsin the early state.The nonlinear machining process would cause complex frequency componentsin the vibration signal,so it was difficult to obtain reliable chatter feature using a single timefrequency analysis method.Wavelet packet decomposition was employed to define the chatter emerging frequency range, and it was reconstructed.The cepstrum of chatter emerging frequency range wasusedto identify the stable, transition and chatter states. The study results show that the method can accurately distinguish the stable, transition and chatter states in end milling processes.

Abstract:In order to analyze the capability and to carry out fault research for two stage double nozzle flapper electrohydraulic servo valve, the overall simulation model of servo valve was established based on AMESim platform. The correctness of the simulation model was verified by the comparison of transient and steady data of output flow obtained from the servo valve capability experiment under step signal. The frequency response curves, flow characteristic, pressure characteristic and other capabilities were analyzed with simulation for frequent faults of the valve. The simulation results make the fault analysis feasible, and can supply a basis for the fault diagnosis of two stage double nozzle flapper electrohydraulic servo valve.