共查询到20条相似文献，搜索用时 93 毫秒
1.
Cone enveloping cylindrical worm in traction machine as instance, theoretical analysis on cylindrical worm transmission has been theoretically analyzed, and efficiency test and load capability test of traction machine with YJ240 cylindrical worm have been done on open power gear experimental instrument. According to the experimental data, it indicates cylindrical worm have some weaknesses on load capability, efficiency, adjustment possibility of tooth backlash and so on. Therefore, on purpose of improving integral performance of traction machine, face worm with variable tooth thickness may be used as primary drive mechanism in traction machine instead of cylindrical worm. 相似文献
2.
The full name of variable tooth thickness plane worm gear transmission is. Backlash adjustable plane worm gear with variable tooth thickness enveloping worm transmission, which is a new kind of accurate power transmission that is intervenient between traditional motion transmission and power transmission. Tooth surface equations of the variable tooth thickness plane worm gear transmission are deduced based on the theory of engagement. Basing on the result, the authors create a finite analysis model of backlash adjustable variable tooth thickness plane enveloping worm with perfect tooth shape by using I-DEAS software, and then has done finite element analysis of backlash adjustable variable tooth thickness plane enveloping worm transmission. Finally, the author drew a conclusion about distribution of principal stress and load distribution between teeth, which offer some references for strength and performance analysis of worm transmission. 相似文献
3.
According to the low voltage power line channel features,combined with adaptive bit loading and power allocation algorithm,an optimal equivalent subchannel algorithm is proposed.Under the condition of fixed amount of transmitted bits and the minimum transmitted power model,impact of optimal equivalent subchannel on the system performance is studied.The optimization algorithm sorts subchannels with similar transmission features into groups,thus the signaling load can be reduced,and the spectrum can be better used.The simulation results show that system can get lower bit error rate(BER) by adopting optimal equivalent subchannel algorithm. 相似文献
4.
Skin electrode unit is a channel through which energy can be transferred to the implanted device by volume conduction. The unit can be equivalent to lumped circuit, but so far there are no appropriate calculation methods of these circuit parameters, so variable load method based on field-circuit coupled is proposed. A skin electrode unit field circuit coupled model is established to obtain the relationship of the network parameters between voltage and current at electrode port, and the amplitude and phase of the power signal is extracted by the use of all phase FFT spectrum analysis. On this basis, equivalent circuit impedance parameters of the skin electrode unit under various conditions are obtained by the application of variable load method and the validity of the method is verified. As a result, the equivalent circuit impedance parameters obtained in this way can be used for the circuit analysis and optimization of the volume conduction energy transfer system. 相似文献
5.
Analysis on tooth root stress and influencing factors of crossed beveloid gears with small shaft angle 总被引：1，自引：0，他引：1
In order to accurately calculate the tooth root stress of spatial crossed beveloid gears with small shaft angle, an exact geometry-based numerical computation method is proposed based on the spatial gearing theory and the finite element theory. Using the proposed method, the mathematical tooth surface model and the mesh model of a crossed beveloid gear pair with small shaft angle is created and the tooth root stress distribution is analyzed. Then the influences of the key design parameter which is the clearance coefficient, torque load, offset error, shaft angle error, pinion axial position error and gear axial position error on the tooth root stress are investigated. The results show that the increasing of the clearance coefficient can decrease the maximum tooth root stress. The root stresses distribute smoothly along the tooth width direction at a light torque load level. For heavy torque load level, the root stresses are parabolic in shape. Also, the existence of offset error and shaft angle error can increase the maximum value of the root stress obviously and the positive and negative value of the errors can change the position of the maximum root stress along opposite direction. For the pinion and gear axial position errors, they have less effect on root stress distribution. 相似文献
6.
A more practical and economic optimization mathematical model of load distribution for industrial boilers is presented. The optimum load rates of boilers are advanced by the method of static boiler model. The target function is built up, and in particular the restrictions are established. The theory of load assignment is checked through a project case. For various industrial boilers, once the definite characteristic functions of fuel consumption are given, the optimal load assigmnent can be obtained using this optimization model. 相似文献
7.
Based on the gray forecast theory, this paper studies the principle and deficiency in power load forecasting by the basic grey model and other improved models, and introduces a new method -the combination grey model to forecast the long-medium power load. Based on an example, the basic grey model, other improved models and combination grey model are used to forecast power load and results of all models are analyzed and compared. The calculation results show that forecasting power load by grey theory is credible and simple. For this type of complex problems such as forecasting the long-medium power load, the combination grey model is specially useful because of it's high precision and facility. The method can be used as one of the tools of forecasting the long-medium power load. 相似文献
8.
Sun Hongbo Xu Guoyu Li Wenyuan 《保鲜与加工》1991,(6):22-27
This paper presents a decomposed optimization model for power network planning. The planning problem is divided into master problem to determine the investment decisions and subproblems to deterimne the operation decisions. In the proposed model, the effects of multi load levels,stochastic line outages,power loss cost and load curtailment cost on the investment decisions are considered. The results of the examples prove the feasibility and effectiveness of the proposed model. 相似文献
9.
The contact analysis on the double enveloping hourglass worm gearing is very important to control its efficient contact zone and contact quality. Nevertheless, current meshing analysis under the rigid condition cannot really reflect its tooth-surface contact. In this paper, the contact Finite Element Method is used to analyze the tooth contact of double enveloping hourglass worm gearing under the manufacturing error and the elastic deformation caused by the load. The load sharing among the contact tooth pairs and variations of contact zone are investigated. As compared with the result of rigid analysis, the contact zone is obviously shifted. This analysis method can provide a base for the conjugating control of the double enveloping hourglass worm gearing. 相似文献
10.
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
11.
Zhu Caichao Qin Datong LiRunfang Cheng Zongyuan 《保鲜与加工》1997,(2):89-94
The epicyclic gear drive with internal tooth has been analysed,the formula has been also deduced for computing the inertial force and change of contact force,and the dynamic optimization of system parameters for the force of bearing has been carried,it has given a reliable proof to reduce the dynamic load and prolong the life of bearing of three ring type reducer. 相似文献
12.
Bearing capacity behavior of roll forming filling screw pile (screw pile for short) is investigated through numerical calculation and static load test. The influence of pile-type parameters, such as width of thread tooth and thread pitch, on the ultimate bearing capacity of crew pile is studied; furthermore, the bearing capacity behavior of screw pile and that of pile with the same diameter are compared and analyzed through static load test. The results show that the ultimate bearing capacity of screw pile is a bit higher than that of pile with the same outside diameter; width of thread tooth has a distinct effect on ultimate bearing capacity which increases with the increment of width of thread tooth. When the screw pile is tested under light load, the resistance on pile side is distributed along screw pile, and tip resistance is small, but the resistance rises considerably with load increasing. Besides, the design formula of bearing capacity of screw pile is proposed. 相似文献
13.
The problem of optimal standby capacity and its valuation in Power Pool is very important and complicated. On the basis of researching literatures concerned, this paper constructs an optimal standby capacity model and researches the problem of pricing optimal standby capacity and determining power price on the user-side. The result shows that the optimal standby capacity at some period t is completely determined by the probability distribution density function of power load demand at this period and surplus power loss and insufficient power loss, and the price of optimal standby capacity is determined by real power price of entering power grid and the power price of forecasting load demand, and the expected power price on the user-side consists of the settlement price with grid loss on generation-side and reasonable gains and expected additional loss. 相似文献
14.
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
15.
The four indexes sensory temperature,temperature-humidity index,cold-humidity index,amenity index in biology meteorology are introduced to compositive analyses the effect of meteorologic factor to power load.Take Chongqing for example,the relation between each compositive index and load is analyzed,and the relation curve of power load and compositive index in observation year is also drawn.The analysis indicates: the load amenity index ratio curve is very stable in all axis range,this indicates amenity index can better reflect the change of power load relative to temperature.At the same time,the effect of rainfall to power load is qualitatively analyzed. 相似文献
16.
Application of data mining method in power load bad data intelligent identification and correction 
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下载免费PDF全文 There is a number of bad data in the load database produced, thus the data must be cleaned before it is used to forecasting electric load or performing power system analysis. The WKFCM measures distance by kernel functions instead of the complicated Euclidean distance and this kernel based distance is used as dissimilarity function of target clustering formula which can reduce the calculation complexity. After the clustering, a super circle covering neural network based identification model for load data is proposed, and the bad data is modified. It is proved that the proposed data processing model has good effect. 相似文献
17.
To obtain the distribution characteristic of contact stress and the bulk temperature on the surface of herringbone gears, parameter modeling of gears was carried out by parametric design language. A numerical simulation was given to calculate the contact stress field and the steady thermal field by combining heat transfer theory, tribology theory, and mesh theory. The distribution of contact stress, the bulk temperature and heat flux also were analyzed. The analysis results show that the distribution of the load along the contact line possesses regularity. The heat flux along the tooth depth direction decreases first and then increases. The effect of thermal conduction of the tooth is stronger than that of convective heat transfer. The conclusion indicates that the finite element emulation method can be used to estimate the transmission performance of herringbone gears. 相似文献
18.
The reliability and reality of load historical data is the foundation of load forecasting.But,the impact load in running power system,and the disturb data in collecting load data through the SCADA may cause much fault data in load historical data. Focusing on solving this problem, a method through adjusting amplitade of its wavele modulus maxima and processing the wavelet decomposed detail signal by soft threshold based on wavelet analysis and singularity theory, then fault date can be eliminated,so that,the real historical imformation and regulation data can be gained by load forecasting. 相似文献
19.
LI Ming-hao 《保鲜与加工》2006,(2):50-53
Generally there have a number of bad data in the electric load data and it affects the precision of load forecasting,so it is necessary for extracting the feature mode of days load data,then cleaning the load data before it is used to forecasting electric load or performing power system analysis.Inspired by soft clustering thought,a intelligent feature mode of days load data extracting method is proposed based on the mutual offset of fuzzy c-means clustering arithmetic and Kohonen self organization feature map neural network.With the merits of not only high extracting precision and convergent speed but also dynamic calculation capability,the method proposed can supply load forecasting or system analysis procedure with due data.Test results using actual data of Chengqu power supply bureau in Chongqing demonstrate the effectivity and feasibility of the method. 相似文献
20.
Loss reduction is important for distribution networks and it is available to reduce loss by loads equalization. With increasing numbers of vertexes in distribution networks, compounding of loads are rapid increasing. It is hard to achieve the global optimization for load balancing by traditional model of distribution networks. Base on analyzing character of loads equalization for distribution networks, this paper provides a new method which conjugate the optimization principle and the hierarchical model of the distribution networks, can transfer the optimization issues into multi stage decision making problems,and can also achieve the optimization equalization of the distribution networks loads. 相似文献