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1.
Based on coordinate measrement of tooth surface of ZC1 worm, the deviation function for evaluating tooth surface is established. According to minimal zone principle, the profility of tooth surface of worm is evaluated. The machining errors of the worm are divided into setting error and adjusting error of the machine and tool. By error compensation, the setting error and adjusting error are corrected and the manufacturing precision of the worm is improved.  相似文献   

2.
鲜食葡萄始终占主导地位是我国葡萄产业发展的一个突出特点.长期以来,我国鲜食葡萄贮运保鲜业一直比较滞后,基本是季产季销,地产地销.因此,我国鲜食葡萄集中产区经常出现采后"运不出、贮不进、销不掉"的被动局面,阻碍了鲜食葡萄产业在适宜栽植区的快速发展.一些非适宜产区为了填补当地鲜食葡萄市场空白,也在积极发展鲜食葡萄生产,其结果必然导致生产成本提高,不利于我国鲜食葡萄的区域化种植和商品化生产基地的建设.  相似文献   

3.
The machine setting reverse method of spiral bevel gear   总被引:2,自引:0,他引:2  
The profile error correction of spiral bevel gears is difficult. To solve this problem, the inspected method of spiral bevel gears tooth surface is studied in 3906 gear measuring center. The grids of tooth surface is measured by measurement software. Taking reference tooth surface as the goal, a method of machine setting reverse using approximation algorithms is proposed, and a mathematical model is build. At last, a reverse example based on grinded spiral gear is given. The result shows that the cutting machine setting of bevel gear tooth surface can be exactly calculated.  相似文献   

4.
A method of modifying the double enveloping worm gearing with developable tooth surface has been proposed to reduce the sensibility of the worm gearing to the manufacturing errors. The tooth contact and kinematic precision of the modified worm gearing with manufacturing errors has been investigated by the TCA method. The results show that by the modification, the edge contact resulting from the manufacturing errors is avoided or effectively relieved,and the kinematic error of the worm gearing is obviously reduced.  相似文献   

5.
A mathematical model for accurate relief grinding of gear hob cutters along radial directions is presented based on the analysis of grinding geometry. Both the design and manufacturing models of gear hob cutters are carefully derived and presented. By employing the plane envelope theory, the reference contour of the grinding wheel is determined in order to attain the design tool profile precisely. The tooth profile error model after regrinding is also given to confirm the grinding parameters. The model provides accurate solutions for both the tool profile and the sectional contour of the grinding wheel. It is simple and straightforward and can be used to produce high precision hob cutters systematically. Two numerical examples are presented to illustrate the effectiveness of the proposed method. The model computing results indicate that the proposed method is practical, precise and reliable. The method provides valuable reference for the design and machining of hob cutters.  相似文献   

6.
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   

7.
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   

8.
In this paper we explain the method of the measurement of the wormwheel profile error with the three coordinate measuring machine. We first establish the wormwheel theoritical tooth profile equation according to the gear engage principle, then write the computing program and calculate the wormwheel theoritical profile, next analyse and calculate the error of the gage head interference. At last, we work out the measuring program and get the wormwheel profile measured with the three-coordinate measuring machine.  相似文献   

9.
This paper develops a generalized 3-dimensional 14-DOF dynamic model for hypoid gear which considers the time-varying friction coefficient and lubrication situation. We propose a mixed elastohydrodynamic lubrication(EHL) friction model of hypoid gear tooth contact to reflect the realistic lubricant situation in gear transmission system consisted of full film contact and asperity contact. Under the mixed lubrication condition, the effects of time-varying friction coefficient on gear dynamic is analyzed. The load sharing coefficient is used to calculate the instantaneous friction coefficient at each contact point along the contact path. Friction coefficient model based on mixed elastohydrodynamic lubrication(Mixed EHL) is incorporated into the dynamic model to predict the dynamic mesh force and transmission error with constant and time-varying friction coefficient. The simulation results under a wide range of speed and load show that the time-varying friction coefficient has a marginal effect on the dynamic response.  相似文献   

10.
A new method of computing the cutter specifications and machine settings for the manufacture of spiral bevel and hypoid gears is studied. And a software system which includes the program models of new and old methods is developed. The system can perform the computations such as blank dimensions,cutting and grinding settings,tooth contact analysis and under cut check of SGM,SFM,SGT,SFT,HGM,HFM,HGT,HFT cutting methods. The new method can allow the user to give the position and length of contact pattern,the direction of contact path and the relative anglar acceleration. The system can be easily operated.  相似文献   

11.
The tooth contact and kinematic precision of cone-generated double-enveloping worm gearing with machining and assembling errors have been investigated. The influence of different errors on driving quality has been discussed. The assembling method to reduce or eliminate the influences of machining errors on tooth contact and kinematic precision has been proposed.  相似文献   

12.
A new analysis method for machining surface profile error is presented in this paper.The linear regression and nonlinear regression are first applied respectively,and then the Weierstrass Mandebrot fractal function is used to obtain the fractal parameters of machining profiles.A minimal parameter set which depicts the machining surface geometric precision is set up,and the surface profile can be reconstructed using these parameters,and an analysis method for part performance and its tolerance structure is proposed.Examples are provided to illustrate the method is feasible and effective.  相似文献   

13.
The stiffness of the tooth with different profile parameters,meshing stiffness and the coefficients of loading distribution allowing for no error are calculated and analyzed on double involute gear with ladder shape teeth for the first time,and the results are made comparison with traditional involute gear;The stiffness of the double involute gear and the meshing stiffness are both increased,and the coefficients of loading distribution are basically unchanged.The energy integration method is also put forth to solve stiffness approximately by linear approximating the tooth profile curve.  相似文献   

14.
For the first time, we point out the new idea that we can approximate the involute tooth profile transmission to circular arc tooth profile transmission. Looking upon it as a fourbar linkage we try to minimax the error of the velocity ratio and evaluate the strong-weak point of circular arc tooth profile transmission.  相似文献   

15.
Reliability model for Subsystems of CNC machine tool with small samples   总被引:1,自引:0,他引:1  
Many subsystems in CNC machine tool have only a few failures, so they are small samples. In this case, classical reliability modeling method often has large errors. For the failure data of small sample, maximum likelihood estimation method is used to estimate the Weibull distribution model parameters of time between failures of the subsystems. Then, the Weibull distribution model parameters are modified by parameter bias correction method. Finally, the effect of bias correction parametersis tested by the D test and the error area ratio test method. The test results show that the modified models are better.  相似文献   

16.
Higher-order elliptical bevel gear is a typical form of the noncircular bevel gear transmission.Space spherical coordinate system of the bevel gear meshing is set up based on the meshing theory of space transmission.The varying relationship among the pitch curve,tooth profile and mesh lines are analyzed,and the equation of the gear tooth surface is developed with matrix method based on space coordinate transformation.The basic parameters of the noncircular bevel gear such as transmission ratio,modulus and the number of teeth are designed,and detailed analysis of the influence of the eccentricity on the relevant parameters is carried out as well.By using discrete numerical method and three-dimensional software,the mathematical model of the tooth profile and virtual physical model of the noncircular bevel gear are established,and then simulation on its motion and interference checking are performed.Finally,the approach for design,calculation and generation of the tooth profile is obtained and its correction has been verified by experiment.  相似文献   

17.
When measuring, virtual instruments are inevitable to cause error damaging the precision of measuring resuits. It presents error constitution, methods of error transfer and synthesis of virtual measuring instrument. Based on the analysis of error transfer and synthesis of virtual measuring tual measuring instrument and gets the method of dealing instrument, it generalizes the error constitution formula of virwith errors. Then, errors can be modifyed.  相似文献   

18.
The analysis method for profile characteristics based on Kauhunen Loeve transform is presented. The profile characteristics are represented using eigenvalues and eigenvectors, thus the error surface profile can easily be reconstructed. The main eigenvectors can be used to monitor and predict the surface error. Examples show that this method is feasible and very effective.  相似文献   

19.
Based on pitting strength, some approaches to enhance power density of gearboxes for wind turbines are discussed. The calculation load is greatly reduced by power division. Allowable stress numbers are effectively increased by improving property of quality materials, precision heat treatment or shot peening. Load capacities can be also obviously enhanced by improving the tooth shape of morphology optimization of tooth root, tooth correction or superfinishing of tooth surface. The center distance is effectively decreased by minishing minimum allowable safety factor or enlarging face width. The power density of gearbox can be further improved by means of structure optimization of planet carrier or uniform load of planetary gear transmission.  相似文献   

20.
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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