Study of Tooth Contact and Kinematic Precision on Cone-Generated Double Enveloping Worm Gearing

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.     

Contact Analysis of worm gearing under the Condition of the Errors and the Load

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.     

Study on Mismatched Engagement of Hourglass Worm Gearing with The Worm Generated by A Cone and The Wheel Generdted by A Straight Profile Hob

A method to make the hourglass worm gearing with the property of mismatchedpoint contact has been proposed.The worm and the hob of the worm gearing is generated by a coneand a straight line located on the cone respectively. The basic principle of the worm gearing has beenanalysed. The formulas for calcultating the machining parameters has been obtained. And the toothcontact of the worm gearing has been investigated.The result shows that this worm gearing could getopint contact well.     

A Solid Modeling and Geometric Analysis of Hourglass Worm Gearing

Based on the theory of conjugate surface and computer graphics, a solid modeling method of hourglass worm gearing is presented. Assembly simulation of worm gearing is carried out, clearance and interference between meshing tooth surfaces are analyzed, and effects of machining and modification of assembling parameters on meshing and contact between tooth surfaces are investigated.     

Study on ZK Worm Gearing with the Property of Controllable Mismatched Contact

A methed to modify the cone-generated cylindric worm gearing(ZK-Wormgearing)with the proprty of controllable mismatched contact has been proposed.The basic principleof the modification has been analysed.The contact state of the worm gearing could be modified bychanging the contact position and the curvature modification amount,which could be realized conveniently by changing the geometric parameter and the setting parameter of the grind wheel in wormmachining.     

THEORETICAL INVESTIGATION OF SPHERE RE-ENVELOPING HOURGLASS WORM GEARING

On the condition of avoiding the"undercutting,"and "sharpening" of worm tooth, it is now regarded as an important subject in the field of meshing principle studying of the "multiple-thread small reducation ratio" hourglass worm gearing with developable tooth surfaces to reduce the gorge pitch circle diameter of worm, raise meshing efficiency and strength of the wheel tooth and improve the unresonable structure of the pair. In this paper, a new type of hourglass worm gearing with developable tooth surfaces -"Sphere Re-nveloping Hourglass Worm Gearing" is studied. It shows that 4a satisfied result to above subject can be obtained if this worm gearing is applied.     

Force Analysis on Meshing Surface and Stress Research of the Cone Roller Enveloping Worm Gearing Transmission

By using the finite element elastic contact analysis method combined with the I-DEAS engineering analysis software, this paper studies the strength of the cone roller enveloping worm gearing,which is a new type of worm gearing transmission,on SUN-4 working station. It also analyzes loading distribution among meshing gears, the contact force distribution along the contact line ,the bending stress distribution and the contact stress distribution of the cone roller enveloping worm gearing with three-tooth meshing instantaneously. Besides,it provides the theoretic basis in the further researches for the new type of worm gearing transmission.     

THEORETICAL INVESTIGATION AND PARAMETER OPTIMIZATION ON ROLLING CONE ENVELOPING HOURGLASS WORM GEARING

In this paper, a new high - strength worm gearing, named'rolling cone enveloping hourglass worm gearing' is proposed. With such a new type of worm gearing, the motion form between meshing tooth surfaces is changed in nature. A systematic theoretical study. a lot of numerical calculations and parameter analyses have been done. Based on these analyses,the optimum design of worm gearing is obtained. It is shown that this worm gearing possesses the virtues of high efficiency, large load capacity, long life -span and easy meanufacture.     

Investigation on Improving Manufacturing Precision of ZC1 Worm

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.     

Study on Contact of Loaded Hourglass Worm Gearing

With the Contact Finite Element Method, the distribution and contact zone of the hourglass worm gearing are calculated. Under the different loads, load among the teeth pairs and variation of contact zone are investigated. The photo elastic experiment has been proceeded for verifying the pressure distribution and load sharing. The result by photo elastic experiment is corresponding to the calculating result with contact FEM.     

The Experimental Study of Lubrication Mechanism of Double Enveloping Hourglass Worm Gearing

According to the characteristic of contact and lubrication of double enveloping hourglass worm gearing,a simplified contact model that can simulate the lubrication mechanism of coupling effect of squeezing effect and entraining effect of this worm gearing is presented.A simulating test set is designed.The lubrication mechanism of coupling effect of squeezing effect and entraining effect is studied experimently by using this set.And the influences of rotation speed,loading speed and depth of oil pocket on the forming of lubrication film and loading ability between contact surfaces are analyzed.Some beneficial conclusions are obtained.     

Application of Error Compensation Methods in High Precision Machining of Globoid Worm

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.     

Research of Ball Worm Gearing

In the paper,a new worm gearing,Ball worm gearing is presented,initiative discussion of its theory of the gearing and design have been done, made a junior advanced development.     

Research on pitch cone design for beveloid gears with crossed axes

Based on the spatial gearing theory, the mathematical model for working pitch cone design of crossed beveloid gears is created. The formulas to determine the transition from point contact to line contact are derived. The direct and in direct methods for pitch cone design of crossed beveloid gears are proposed. The effects of gearing parameters on the angle between the first principle directions are analyzed. The loaded tooth contact analysis is performed using FEM theory. The conclusion indicates that: the angle between the first principle directions is more sensitive to cone angles than to the helix angle. The increase of the angle between the first principle directions can obtain smaller contact area, higher transmission error and lower mesh stiffness. A practical tooth bearing test is conducted to demonstrate the proposed design procedure and the experimental result compared well with the simulation. For the matching design and optimization of beveloid gears, it has both the theoretical and project practical significance.     

Design and experimental validation of a novel double ring plate gear reducer

A novel double ring plate gear reducer (DRPGR) is designed and its experimental validation is conducted. By using the closed graph method, the modification coefficients of internal gearing in DRPGR are determined. Based on this, the overall structure of the reducer is designed and its kinematics simulation is achieved. With APDL programming language of ANSYS, a 3D finite element (FE) model of DRPGR is established, and its modal analysis and loaded tooth contact analysis (LTCA) are conducted respectively. The modal analysis reveals that the lower natural frequencies of DRPGR are much higher than the input frequency and the lower modes can be classified as vertical and horizontal bending of input and output shafts. The LTCA indicates that three pairs of gear teeth contact simultaneously at rated output torque. Due to the multi teeth contacts, the maximum stress is much lower than the permissible stress of internal gearings. The experimental tests of the prototype validate that DRPGR is adapted to both single driven and dual driven work condition. When single droved, DRPGR can eliminate the kinematic uncertainty by non 180 degree phase difference design. DRPGR claims a better dynamic performance in dual driven work condition. The efficiency of DRPGR increases with the increment of output torque and the reducer has an excellent short term overloaded capacity. The experimental results validate that the proposed method can be used to guide the design of that kind of reducer.     

Analysis on tooth root stress and influencing factors of crossed beveloid gears with small shaft angle

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.     

Bending Stress Analysis on Backlash Adjustable Worm Transmission

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.     

Analysis on Oylindrical Worm in Traction Machine and Modifications

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.     

DEVELOPMENT AND TEST ON ROLLING CONE ENVELOPING HOURGLASS WORM PAIR

The rolling cone enveloping hourglass worm pair has been successfully developed, in which there is almost only rolling friction between the meshing tooth surfaces, and both the worm and wormwheel have hard surfaces. Such a new type of hourglass worm pair is particularly-favorable for power transmission. This paper presents the design. manufacting and testing of this worm pair.     

Profile Precision of Hypoid Gears Controlled by Coordinate Measurements

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.