共查询到20条相似文献，搜索用时 31 毫秒
1.
Huang Changhua Zheng Changqi Zu Zhenghua 《保鲜与加工》1991,(3):22-24
The tooth contact mechanism of hypoid gear under load with similar model experiments is presented and the effect of mounting deflections and tooth deformation on tooth contsct is discussed. Thus, the basis of founding loaded tooth contact analysis calculating method of hypoid gear is brought about. 相似文献
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Considering that the transmission system of wind turbine works in complex and changing load environment caused by stochastic wind speed,this paper uses sparse least squares support vector machine(SL-SVM) to simulate wind speed of true wind field,and obtains time-varying wind load caused by stochastic wind speed. The lumped-parameter method is used to develop a dynamic model of planetary gear transmission system of wind turbine coupled with bearing. The model includes the varying wind load,time-vary mesh stiffness of gear pair and time-vary stiffness of rolling element bearing. The numerical method is used to simulate the dynamic performance of planetary gear system of Multibrid Technology Wind Turbine with 1.5 MW rated power. The vibration displacement responses of the transmission system are obtained as well as dynamic meshing force each pair of gear and nonlinear bearing forces. The research can provide a foundation for optimizing dynamic performance and reliable design of gear transmission system of wind generator. 相似文献
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A dynamic model of transmission system for a marine gear is established considering time-varying mesh stiffness, mesh damping and tooth composite error. The solution efficiency is improved by taking contact line length change of gear pair instead of instantaneous gear mesh stiffness change and making mesh damping and tooth surface equivalent to viscous damping. Multi-objective dynamic optimization design is put into practice to improve the marine gear transmission system using vibration acceleration and mass as target function. The results show that the optimization method can effectively reduce the vibration level and mass of marine gear. 相似文献
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Based on study of elastohydrodynamic lubrication (EHD) and meshing theory of planar worm gear drive, EHD model for the drive is proposed. Minimum film thickness on the whole contact area is calculated. EHD status for the drive is analyzed. The distributions of film thickness show that, EHD status during entry engagement is better than that during exit engagement, and EHD status of worm addendum area is better than that of dedendum area. Influencing factors such as work conditions and optimized parameters along with their effects were analyzed. Theoretical analysis suggests that the optimizing pressure angle and increasing worm pitch diameter have influence on improving lubricant performance of the planar worm gear drive. 相似文献
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To address the problems of low carrying capacity and short life of bearings in current ring reducers, a new type of ring reducer is proposed which consists of a two stepped transmission. One is a planetary transmission, and the other is an N type planetary transmission with a low tooth number difference. Based on the analysis of structural features, the transmission principle, and a transmission load situation, a contact finite element model of the new type of ring reducer is set up, and the stress value and the actual pairs of meshing teeth are derived by calculation. Based on gear modification research theory, the second stage transmission gear pairs of the new reducer are modified on its teeth profiles. Results demonstrate that the load capacity of transmission gear pairs have been enhanced greatly. 相似文献
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In order to study the influences of different factors on nonlinear dynamics of face-gear transmission system, a nonlinear dynamic model is presented. This model includes backlash, general transmission error, time-varying meshing stiffness, meshing damping, bearings and external load, etc. Based on numerical analysis theory of nonlinear dynamics, the equations are solved and the bifurcation characteristics with different parameters are obtained. And the calculation results show that increasing the backlash and time-varying meshing stiffness will augment the dynamic load of system, but increasing the mesh damping will reduce the dynamic load effectively. 相似文献
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A dynamic model of NGW helical planetary gear transmission for high-power wind turbine gearbox is established by considering these factors as errors of gears and time-varying mesh stiffness by using mass centralized method. Moreover, the random wind velocity is simulated as external seismic excitation making the results more conform to practical condition. And on this basis, this system is optimized for minimum gearbox volume and minimum component torsional acceleration with the restriction of reliability and strength restrain. The result indicates that the optimized parameters make gear transmission lightweight and the dynamic property improved so as to reduing vibration and noised. 相似文献
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Ultra High Molecular Weight Polyethylene (UHMW-PE) is a kind of high anti-wear engineering plastic with many excellent physical and mechanical performances. It has been widely applied in the field of mechanism such as bearing and pump. Effect of load, speed, time on friction and wear properties of Ultra High Molecular Weight Polyethylene(UHMW-PE)plastic alloy bearings under different Lubricating Condition are studied by using MPV-200 model friction and wear testing machine. The test results show that water lubrication reduces the friction coefficient of bearings but increases the wear rate as compared with dry friction. At the same time, wear mechanisms are analyzed systemically. It provides a theoretic basic for practical application of plastic alloy bearings 相似文献
10.
Numerical simulation of the internal dynamic excitation of a spiral bevel gear transmission 总被引：1，自引：0，他引：1
A 3-D geometry model and a static/dynamic finite element (FE) model of a spiral bevel gear transmission are established. Using ANSYS software, the mesh stiffness excitation of a tooth pair is calculated via the static contact FE method. Using LS 相似文献
11.
为揭示机体弹性变形对曲轴主轴承润滑特性的影响,在考虑整机体和曲轴弹性的条件下,建立发动机曲柄连杆机构多柔体动力学模型,耦合基于质量守恒边界条件的广义雷诺方程和Greenwood/Tripp接触模型,分析机体弹性变形对曲轴主轴承润滑特性的影响。结果表明：与刚性机体相比,计入机体弹性变形后,各主轴承的润滑特性随曲轴转角的变化趋势与将缸体处理为刚性时基本一致;润滑油平均端泄量和总摩擦功耗在一个工作循环内均变化较小;润滑油最小油膜厚度、最大油膜压力和轴承的最大粗糙接触压力在一个工作循环内的某些时刻变化明显。 相似文献
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Although rolling lubrication can decrease rolling forces and energy consumption, it also causes defects such as uneven flange lateral spread and web eccentricity during H-beam rolling process. To solve the problem caused by lubrication, finite element models of H-beam universal rolling were established. The different friction conditions of the contact surface between the rollers and work piece were simulated individually. The mechanism of rolling lubrication impacting on flange spread was studied, and the law of flange lateral spread was gained by analyzing the factors such as friction distribution and metal flow in different situations. Analytical results show that lubrication in rolling process can effectively decrease rolling forces and energy consumption. In the condition that technological parameters except friction are fixed, the flange lateral spread decreases in a linear way as the friction coefficient between flange and roller increases, and the flange lateral spread is more sensitive to the friction of flange's the inner side. Design of lubrication process should take full account of the sensitiveness differences of flange lateral spread to the lubrication conditions of different parts of roller surface. 相似文献
13.
Dynamic characteristics of multi-stage planetary gear trains in shield machine cutter drive 
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下载免费PDF全文 A purely torsional dynamic model of multi-stage planetary gear trains is developed to investigate the dynamic characteristics of the transmission system in shield machine cutter drive. In the model,phase difference between mesh stiffness and error among each stage caused by different initial mesh positions is considered,and other factors such as component bearing stiffness,time-varying mesh stiffness and error are considered as well. Inherent characteristic analysis shows there are more unique and diverse vibration modes in multi-stage planetary gear trains than in single-stage planetary gear trains. Through dynamic response analysis,time-domain and frequency-domain response of dynamic meshing force of each stage is obtained. As the frequency of exciting force of medium-speed and high-speed stage is in proximity to the natural frequency of the system,harmonic resonance tends to occur,which needs to be paid great attention to. Dynamic factors of each stage are also computed and prepare the ground for the dynamic optimizing design of planetary gear trains. 相似文献
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A new worm driving,i.e. planar internal gear enveloping crown worm driving,is presented. Its mathematical model of meshing functions and teeth surface equations are established basing on the theory of differential geometry and gear mesh. Various types of the driving,the macroscopic meshing performance and the microcosmic meshing performance are analyzed. The results show that the inclination angle of generating plane determines the distribution of contact lines,the planar internal gear primary-enveloping crown worm driving has ideal lubrication property,and the planar internal gear second-enveloping crown worm driving has high loading capacity. The studies are practicably instructive for developing new worm driving with high loading capacity,ideal lubrication and small volume. 相似文献
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Gear transmission with meshed medium belt is proved feasiable which is, with lower vibration and noises, lower cost and energy saving. To realize "green lubrication". In the type of gear transmission, the medium belt is the feature component, also is one of the key components. The life of medium belt has great effects on the efficiency and performance of the whole transmission. However, in the process of transmission the medium belt is subjected to great tension stress, and easy to break. So we take measures to analyze the tension stress ,compression and friction forcel of the medium belt at first, and take it as the inference to select the materials of the medium belt. 相似文献
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The geometrical model of profile error is put forward to describe the tooth surface precision of hypoid gears. The influence of each machine tool setting error on profile error is investigated respectively, and the research of the associativity and compensativity among the machine tool errors are made. The setting errors of machine tool, the optimal modifying parameters and their value are got from the measurement coordinates of hypoid gear real tooth surface, and the adjusted manufacturing shows the geometrical precision of the tooth surface is improved effectively. 相似文献
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The study object of this paper is helical beveloid gears with parallel axis. Based on the gear Mshing Principles and the tooth-surface equations of pinion and gear,the mathematical model of tooth contact is developed under standard installation and installations with center distance error,axis error and multiple error respectively. The MATLAB solver is used to obtain the contact trace and the transmission error under different installing conditions and the comparative analysis is made. The results indicate that this gear drive is sensitive to axis installation errors,it forms the edge contact and cause the periodic transmission error. It can provide the foundation for designs and analysis of this gear transmission. 相似文献
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As metal Belt CVT(Continuously Variable Trans mission) acts as a kind of friction transmission, friction coefficient is a key parameter of CVT. The friction characters of CVTF(Continuously Variable Transmission Fluid) are mainly determined by fluid and contact state. The contact between belt and pulley can be regarded as a kind of contact between cylinder and cone. As their contact line is short, the curvature change of pulley along the contact line can be neglected. Then the contact problem of belt and pulley was reasonably simplified as a contact between cylinder and cylinder. Under the state of equivalent maximum stress, the contact friction condition of metal belt and pulley was simulated by the contact of ring and block in Timken Friction Test Machine. 相似文献
20.
The determination of load share between teeth is a complex problem in gear strength calculation. On the basis of contact finite element method this paper considers the production-assembly error as initial gap to get the finite element model which meets load share between teeth in gear meshing. Through calculating and comparing the result with that from ISO formula to get the load share between teeth which meets the requirements in actual usage. 相似文献