scholarly journals Investigation of Increasing the Tooth Surface Quality of Curvilinear Involute Gears

Author(s):  
mahir uzun ◽  
Şemsettin TEMİZ ◽  
Mehmet Sinan ÇETİN

Abstract It is not possible to increase the surface quality of non-standard gears with curved involute tooth profile produced by 5-axis CNC milling method with standard gear grinding methods due to curved tooth profiles. In this study, the possibilities of increasing the surface quality of non-standard gears with curved involute tooth profile were investigated in order to expand their use in the industry. For this purpose, the target model was produced by using the mathematical parametric equations of the involute curve that forms the profile form of a tooth in the CAD environment. By using the target model, manufacturing codes were derived in the CAM environment, and gears with curved involute tooth profile were produced on a 5-axis CNC machine. Then these gears; The possibilities of increasing the tooth profile surface quality were investigated by applying four different methods, such as precision finishing, co-running in oil, co-running in oil with SiC added, and grinding on a 5-axis CNC machine with a finger grinding tip specially produced for gears. In the oil co-run method, considering the running-in stage for each method, the gears were tested with the help of the designed gearbox, at a revolution speed of 670 rpm, by turning a total of 150,000 turns in 6 periods of 25,000 turns. In the co-start method, the gears at the beginning of the test and at the end of each period; thermal records, noise analysis, photographic records, surface roughness values (Ra, Rz) were measured. In the co-operation methods applied to increase the surface quality, the tooth surface of the gears at the beginning of the test and at the end of each period; photographic records, surface roughness values (Ra, Rz) were measured, noise levels were measured during the test and thermal records were taken. Similarly, in precision machining and grinding methods, photographic recordings of the tooth surface were taken, surface roughness (Ra, Rz) was measured, micrographs were taken in SEM and analyzed after the process. As a result of the tests and analyzes carried out; It has been observed that the surface quality is the best in the process performed using a specially produced finger grinding tip and a CNC grinding machine.

2021 ◽  
Author(s):  
Mingyang Wu ◽  
Jianyu Zhang ◽  
Chunjie Ma ◽  
Yali Zhang ◽  
Yaonan Cheng

Abstract Contour bevel gears have the advantages of high coincidence, low noise and large bearing capacity, which are widely used in automobile manufacturing, shipbuilding and construction machinery. However, the quality of the tooth surface has a significant impact on the transmission accuracy of the gear, so it is of great significance to optimize the surface quality of the contour bevel gear. This paper firstly analyzes the formation process of machined surface roughness of contour bevel gears on the basis of generating machining method, and dry milling experiments of contour bevel gears are conducted to analyze the effects of cutting speed and feed rate on the machined surface roughness and surface topography of the workpiece. Then, the surface defects on the machined surface of the workpiece are studied by SEM, and the causes of the surface defects are analyzed by EDS. After that, XRD is used to compare the microscopic grains of the machined surface and the substrate material for diffraction peak analysis, and the effect of cutting parameters on the microhardness of the workpiece machined surface is investigated by work hardening experiment. The research results are of great significant for improving the machining accuracy of contour bevel gears, reducing friction losses and improving transmission efficiency.


Author(s):  
Ravi Datt Yadav ◽  
Anant Kumar Singh ◽  
Kunal Arora

Fine finishing of spur gears reduces the vibrations and noise and upsurges the service life of two mating gears. A new magnetorheological gear profile finishing (MRGPF) process is utilized for the fine finishing of spur gear teeth profile surfaces. In the present study, the development of a theoretical mathematical model for the prediction of change in surface roughness during the MRGPF process is done. The present MRGPF is a controllable process with the magnitude of the magnetic field, therefore, the effect of magnetic flux density (MFD) on the gear tooth profile has been analyzed using an analytical approach. Theoretically calculated MFD is validated experimentally and with the finite element analysis. To understand the finishing process mechanism, the different forces acting on the gear surface has been investigated. For the validation of the present roughness model, three sets of finishing cycle experimentations have been performed on the spur gear profile by the MRGPF process. The surface roughness of the spur gear tooth surface after experimentation was measured using Mitutoyo SJ-400 surftest and is equated with the values of theoretically calculated surface roughness. The results show the close agreement which ranges from −7.69% to 2.85% for the same number of finishing cycles. To study the surface characteristics of the finished spur gear tooth profile surface, scanning electron microscopy is used. The present developed theoretical model for surface roughness during the MRGPF process predicts the finishing performance with cycle time, improvement in the surface quality, and functional application of the gears.


2009 ◽  
Vol 69-70 ◽  
pp. 253-257
Author(s):  
Ping Zhao ◽  
Jia Jie Chen ◽  
Fan Yang ◽  
K.F. Tang ◽  
Ju Long Yuan ◽  
...  

Semi-fixed abrasive is a novel abrasive. It has a ‘trap’ effect on the hard large grains that can prevent defect effectively on the surface of the workpiece which is caused by large grains. In this paper, some relevant experiments towards silicon wafers are carried out under the different processing parameters on the semi-fixed abrasive plates, and 180# SiC is used as large grains. The processed workpieces’ surface roughness Rv are measured. The experimental results show that the surface quality of wafer will be worse because of higher load and faster rotating velocity. And it can make a conclusion that the higher proportion of bond of the plate, the weaker of the ‘trap’ effect it has. Furthermore the wet environment is better than dry for the wafer surface in machining. The practice shows that the ‘trap’ effect is failure when the workpiece is machined by abrasive plate which is 4.5wt% proportion of bond in dry lapping.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shimin Dai ◽  
Hailong Liao ◽  
Haihong Zhu ◽  
Xiaoyan Zeng

Purpose For the laser powder bed fusion (L-PBF) technology, the side surface quality is essentially important for industrial applicated parts, such as the inner flow parts. Contour is generally adopted at the parts’ outline to enhance the side surface quality. However, the side surface roughness (Ra) is still larger than 10 microns even with contour in previous studies. The purpose of this paper is to study the influence of contour process parameters, laser power and scanning velocity on the side surface quality of the AlSi10Mg sample. Design/methodology/approach Using L-PBF technology to manufacture AlSi10Mg samples under different contour process parameters, use a laser confocal microscope to capture the surface information of the samples, and obtain the surface roughness Ra and the maximum surface height Rz of each sample after analysis and processing. Findings The results show that the side surface roughness decreases with the increase of the laser power at the fixed scanning velocity of 1,000 mm/s, the side surface roughness Ra stays within the error range as the contour velocity increases. It is found that the Ra increases with the scanning velocity increasing and the greater the laser power with the greater Ra increases when the laser power of contour process parameters is 300 W, 350 W and 400 W. The Rz maintain growth with the contour scanning velocity increasing at constant laser power. The continuous uniform contour covers the pores in the molten pool of the sample edge and thus increase the density of the sample. Two mechanisms named “Active adhesion” and “Passive adhesion” cause sticky powder. Originality/value Formation of a uniform and even contour track is key to obtain the good side surface quality. The side surface quality is determined by the uniformity and stability of the contour track when the layer thickness is fixed. These research results can provide helpful guidance to improve the surface quality of L-PBF manufactured parts.


2019 ◽  
Vol 889 ◽  
pp. 155-160
Author(s):  
Trong Mai Nguyen ◽  
Đuc Quy Tran ◽  
Van Nghe Pham ◽  
Van Canh Nguyen

In this research work, the result of the effects of technological parameters on surface roughness in extrusion bars of aluminum alloy were pesented. The results of this study may be used for choosing optimal parameters of extrusion process so that surface quality of extruded bar was improved.


2020 ◽  
Vol 10 (18) ◽  
pp. 6265
Author(s):  
Vasiliki Kamperidou ◽  
Efstratios Aidinidis ◽  
Ioannis Barboutis

The surface roughness constitutes one of the most critical properties of wood and wood veneers for their extended utilization, affecting the bonding ability of the veneers with one another in the manufacturing of wood composites, the finishing, coating and preservation processes, and the appearance and texture of the material surface. In this research work, logs of five significant European hardwood species (oak, chestnut, ash, poplar, cherry) of Balkan origin were sliced into decorative veneers. Their surface roughness was examined by applying a stylus tracing method, on typical wood structure areas of each wood species, as well as around the areas of wood defects (knots, decay, annual rings irregularities, etc.), to compare them and assess the impact of the defects on the surface quality of veneers. The chestnut veneers presented the smoothest surfaces, while ash veneers, despite the higher density, recorded the highest roughness. In most of the cases, the roughness was found to be significantly lower around the defects, compared to the typical structure surfaces, probably due to lower porosity, higher density and the presence of tensile wood. The results reveal that the presence of defects does not affect the roughness of the veneers and increases neither the processing requirements of the veneer sheets before finishing, nor the respective production cost of veneers and the veneer-based wood panels. The high utilization prospects of the examined wood species in veneer production, even those bearing various defects, is highlighted.


Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1758
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Nikolaos Vaxevanidis ◽  
John Kechagias

An experimental investigation of the surface quality of the Poly-Jet 3D printing (PJ-3DP) process is presented. PJ-3DP is an additive manufacturing process, which uses jetted photopolymer droplets, which are immediately cured with ultraviolet lamps, to build physical models, layer-by-layer. This method is fast and accurate due to the mechanism it uses for the deposition of layers as well as the 16 microns of layer thickness used. Τo characterize the surface quality of PJ-3DP printed parts, an experiment was designed and the results were analyzed to identify the impact of the deposition angle and blade mechanism motion onto the surface roughness. First, linear regression models were extracted for the prediction of surface quality parameters, such as the average surface roughness (Ra) and the total height of the profile (Rt) in the X and Y directions. Then, a Feed Forward Back Propagation Neural Network (FFBP-NN) was proposed for increasing the prediction performance of the surface roughness parameters Ra and Rt. These two models were compared with the reported ones in the literature; it was revealed that both performed better, leading to more accurate surface roughness predictions, whilst the NN model resulted in the best predictions, in particular for the Ra parameter.


2020 ◽  
Vol 10 (5) ◽  
pp. 1667 ◽  
Author(s):  
Basem M. A. Abdo ◽  
Abdualziz El-Tamimi ◽  
Emad Abouel Nasr

Pocket milling has been regarded as one of the most widely used operations in machining. The surface quality of the machined pockets is an essential aspect of any engineering and medical applications. In the current study, rotary ultrasonic machining (RUM) was applied for milling micro-pockets on alumina (Al2O3) ceramic. The objective of this research was to analyze the effect of the tool overlapping parameters on the surface roughness, surface morphology and the profiles of the machined pockets. Subsequently, the effect of different tool path strategies was analyzed on the surface quality and the material removal rate (MRR) of the machined pockets. A scanning electron microscope is used for analyzing the tool wear mechanisms. The experimental results provide evidence that the surface roughness, surface morphology and the MRR have been significantly affected by the considered tool overlapping and the tool path strategies. Furthermore, among the selected tool overlapping parameters (5–25%) and the tool path strategies, the best surface roughness (Ra = 0.155 μm and Rt = 1.432 µm) of the machined pockets can be found at 20% of the tool overlapping with a mix of uni-directional and zigzag tool path strategy.


Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.


2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850033
Author(s):  
WENYONG SHI ◽  
YAN MA ◽  
CHUNMEI YANG ◽  
BIN JIANG ◽  
ZHE LI

Milling processing is an important way to obtain wood–polyethylene composite (WPC) end products. In order to improve the processing efficiency and surface quality of WPC and meet the practical application requirements, this paper focussed on morphology and roughness of the WPC-milled surface and studied surface quality changes under different cutting parameters and milling methods through multi-parameters milling experiments. The milling surface morphology and roughness of WPC were analyzed and measured during cut-in, cutting and cut-out sections. It also revealed the affect rule of different cutting parameters and milling methods on milled surface morphology and roughness. The results show that the milling surface roughness of WPC products with wood powder content of 70% is significantly larger than the one whose wood powder content is 60%, and defects such as holes are also relatively more. Finally, a surface roughness prediction model was established based on the mathematical regression method and its multi-factor simulation was carried out. A comparative analysis of predictive and experimental values was performed to verify the reliability of the model. It could also provide theoretical guidance and technical guarantee for high processing quality of WPC milling and cutting.


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