Theoretical Basis of Generation of Face Worm Gear Drive With Duplex Worm

Author(s):  
Andrzej Gessner

New type of face worm gear drive with double-lead worm is proposed. The advantages of that gear in comparison to contemporary known gears are also mentioned. The shaping process of the face worm gear is carrying out by means of a single point tool. The same insert is used for cutting the duplex worm. Using a single point tool instead of hobbing cutter considerably reduces the manufacturing cost, in which the share of tool production plays the main role. The shaping process is performed on a CNC milling machine with or without additional equipment. Two main methods of shaping depended on setting up the tool machine are presented. One of them requires no special equipment but a single point tool with insert of specific tool included angle, whilst the second uses a constructed tooling. There are also described 3 methods of shaping the face toothing, which depends on the used technology. Geometry of that face worm gear drive is presented and described. The tooth depth is constant along the whole tooth line. Nominal width of tooth section as well as its location depends on the lead difference of the worm. Provided scheme can be used to calculate those parameters. The total length of the duplex worm is calculated by taking into consideration the internal and external diameters of the worm gear and the additional length which is needed to reduce the backlash. The shape and size of the single point tool is determined according to the worm and the necessary geometric model is provided. There are also given criteria, which limit the maximum length of worm and its maximum lead angle. A complete algorithm describing the designing process of that type of gear is presented in the final part of the article.

2014 ◽  
Vol 8 (2) ◽  
pp. 45-50
Author(s):  
Illés Dudás ◽  
Sándor Bodzás

Based on the general mathematical model of Illés Dudás which is appropriate for mathematical modelling of production technology methods we have worked out a model for resharpening analysis of conical hob. After the hob resharpening using numerical calculations the determination of the tooth surface of face gear by cutting edges is necessary for the analysis. Based on this methods we could calculate the permissible critical angle of the hob and the profiles of the hob and the face gear in axial section. The permissible critical angle of the hob is the critical angle the hob cutting edge of which manufactured face gear profile is situated in the permissible profile error tolerance. We have worked out a new geometric conical worm gear drive that is the conical worm gear drive having arched profile. Using this mathematical model we have done resharpening analysis for the hob having arched profile and determined the permissible critical angle.


Author(s):  
M-F Tsay ◽  
Z-H Fong

Owing to modern forging and moulding technology, not only are increasing numbers of face gears being made by die, but the quality of the moulded face gear is comparable to that for gears made by a shaping process. The contact pattern of the face gear drive is designed in a manner similar to that for the bevel gear, with a localized bearing that reduces the sensitivity of axes misalignment. This paper proposes a novel profile modification methodology for the moulded face-gear drive that enhances the controllability of the contact pattern and transmission characteristics. Specifically, a skew double crowning is applied on the tooth surface of a face gear whose pinion is a standard involute helical gear. The proposed method - for which computer-aided design software for the tooth surface geometry was developed - can also separately control the bias angle and bearing ratio of the contact pattern, as well as the amplitude of transmission error. Overall, as shown here using several numerical examples, the proposed modified methodology is highly flexible.


2010 ◽  
Vol 455 ◽  
pp. 594-598 ◽  
Author(s):  
Ying Liang Yu ◽  
Zai Dan Geng

One of the significant features of CNC technological superiority is in the practical applications, according to the necessary movement of processed parts required, we can use generating method to transform CNC machine tools and receive the desired results. This article discussed under the premise that lack of special equipment, transforming ordinary horizontal CNC milling to machine worm gear. The advantage of this numerical transformation approach is using the processing functions of thread and tapered thread instruction, skillfully translating into control of the CNC machining worm, expanding the CNC machining capabilities and the scope of practical application. Also apply the advantages of CNC technology, reduce or eliminate the accumulation of worm in the processing of pitch error which makes the worm processing precision and smoothness of worm drive better. This paper discussed the principles of numerical control transformation, transformation of milling machine structure and the conversion calculation of parameters in programming, analyzed the causes and processing effects of worm gear processing errors control and accuracy improving.


2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110349
Author(s):  
Huiqiang Guo ◽  
Mingzhe Li ◽  
Pengfei Sun ◽  
Changfeng Zhao ◽  
Wenjie Zuo ◽  
...  

Rotary-wing unmanned aerial vehicles (UAVs) are widespread in both the military and civilian applications. However, there are still some problems for the UAV design such as the long design period, high manufacturing cost, and difficulty in maintenance. Therefore, this paper proposes a novel design method to obtain a lightweight and maintainable UAV frame from configurable design to detailed design. First, configurable design is implemented to determine the initial design domain of the UAV frame. Second, topology optimization method based on inertia relief theory is used to transform the initial geometric model into the UAV frame structure. Third, process design is considered to improve the manufacturability and maintainability of the UAV frame. Finally, dynamic drop test is used to validate the crashworthiness of the UAV frame. Therefore, a lightweight UAV frame structure composed of thin-walled parts can be obtained and the design period can be greatly reduced via the proposed method.


2013 ◽  
Vol 371 ◽  
pp. 133-137
Author(s):  
Radu Eugen Breaz ◽  
Melania Tera ◽  
Octavian Bologa ◽  
Sever Gabriel Racz

The paper presents a joint theoretical and experimental approach to determine the technological forces within the asymmetric single point incremental forming ASPIF process, based upon a theoretical model, image processing and data acquisition. The first step of this approach was to develop a theoretical model of the forces within the process, based upon the model of a mechanical feed drive of a CNC milling machine. By means of this model, relationships between the resistant torque at the motor spindle level and the technological force on the movement axis could be determined. Using an image processing method, which allowed the user to extract information within the machines operator panel and analytical relationships, the technological forces were determined. The results were compared with the measured values, obtained by means of a data acquisition system.


Author(s):  
Shalin Marathe ◽  
Harit Raval

Abstract The automobile, transportation and shipbuilding industries are aiming at fuel efficient products. In order to enhance the fuel efficiency, the overall weight of the product should be brought down. This requirement has increased the use of material like aluminium and its alloys. But, it is difficult to weld aluminium using conventional welding processes. This problem can be solved by inventions like friction stir welding (FSW) process. During fabrication of product, FSW joints are subjected to many different processes and forming is one of them. During conventional forming, the formability of the welded blanks is found to be lower than the formability of the parent blank involved in it. One of the major reasons for reduction in formability is the global deformation provided on the blank during forming process. In order to improve the formability of homogeneous blanks, Single Point Incremental Forming (SPIF) is found to be giving excellent results. So, in this work formability of the welded blanks is investigated during the SPIF process. Friction Stir Welding is used to fabricate the welded blanks using AA 6061 T6 as base material. Welded blanks are formed in to truncated cone through SPIF process. CNC milling machine is used as SPIF machine tool to perform the experimental work. In order to avoid direct contact between weld seam and forming tool, a dummy sheet was used between them. As responses forming limit curve (FLC), surface roughness, and thinning are investigated. It was found that use of dummy sheet leads to improve the surface finish of the formed blank. The formability of the blank was found less in comparison to the parent metal involved in it. Uneven distribution of mechanical properties in the welded blanks leads to decrease the formability of the welded blanks.


Author(s):  
I. H. Seol ◽  
Faydor L. Litvin

Abstract The worm and worm-gear tooth surfaces of existing design of Flender gear drive are in line contact at every instant and the gear drive is very sensitive to misalignment. Errors of alignment cause the shift of the bearing contact and transmission errors. The authors propose : (1) Methods for computerized simulation of meshing and contact of misaligned worm-gear drives of existing design (2) Methods of modification of geometry of worm-gear drives that enable to localize and stabilize the bearing contact and reduce the sensitivity of drives to misalignment (3) Methods for computerized simulation of meshing and contact of worm-gear drives with modified geometry The proposed approach was applied as well for the involute (David Brown) and Klingelnberg type of worm-gear drives. Numerical examples that illustrate the developed theory are provided.


Author(s):  
F. L. Litvin ◽  
D. J. Kin ◽  
Y. Zhang

Abstract Gear tooth surfaces being in line contact at every instant are considered. The dimensions of the contacting surfaces must be limited in order to avoid: (i) the appearance of the envelope of lines of contact on the generating surface Σ1 and (ii) the appearance of singular points on the generated surface Σ2. The relations between the developed concepts and the Wildhaber’s concept of the limiting pressure angle are investigated. Applications to the worm-gear drive and the generation of a pinion of a formate gear drive are considered. Computer graphics have been used to illustrate the results of computation.


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