Predictive modelling and parametric optimization of minimum quantity lubrication assisted hobbing process

Abstract: This paper focuses on parametric analysis, modelling, and parametric optimization of minimum quantity lubrication assisted hobbing (MQLAH) using environment friendly lubricant for manufacturing superior quality spur gears. Influences of hob cutter speed, axial feed, lubricant flow rate, air pressure and nozzle angle on the deviations in total profile, total lead, total pitch and radial runout and flank surface roughness parameters were studied by conducting 46 experiments using Box-Behnken method of response surface methodology. Results revealed that effect of air pressure is negligible but other parameters have significant impact on the considered responses. Back propagation neural network (BPNN) model was developed to predict microgeometry deviations and flank surface roughness values of the MQLAH manufactured spur gears. The BPNN predicted results found to be very closely agreeing with the corresponding experimental results with mean square error as 0.0063. Real-coded genetic algorithm (RCGA) was used for parametric optimization of MQLAH process to simultaneous minimization of microgeometry deviations and flank surface roughness. Standardized values of the optimized parameters were used to conduct confirmation experiment whose results had very good closeness with RCGA computed and BPNN predicted values and produced spur gear of superior quality. This study proves MQLAH to be a potential sustainable replacement of conventional flood lubrication assisted hobbing for manufacturing cylindrical gears of better quality

MANET Congestion Control Mechanism - Challenges and Survey

The transport layer plays a crucial role in the Mobile Adhoc Network (MANET) protocol stack by controlling traffic flow, managing congestion, and enabling end-to-end delivery. With the help of congestion control mechanisms, numerous protocols are formed to enhance MANET performance. This paper focuses on a thorough analysis of the challenges the MANET protocol stack is facing as a result of congestion control issues such high overload, long delays, and increased packet loss. Finally, note that in order to increase MANET performance, research needs to concentrate on specific congestion control mechanisms

MANET Hidden and Exposed Terminal - Challenges and Survey

Mobile Adhoc Network (MANET)is a self organized wireless Network which was created to communicate among  the nodes without support of the any Infrastructure. While transmission of the packets between the nodes, many challenges the every nodes faces. One of the Major challenges is Hidden and Exposed nodes issues in the MANET. This causes the packet drop or packet failure while the transmitting the packets. Also which  reflects in degrades the throughput of the MANET and performance of the MANET nodes when the heavy traffic ,retransmission of the dropped packets delayed the communication. This article discussed about hidden and Exposed terminal problem and challenges in MANET and also dissimilar survey in MANET

Near-net shape manufacturing of miniature spur gears by wire spark erosion machining

This work describes an experimental investigation with the aim to evaluate and establish wire spark erosion machining (WSEM) as a viable alternative for high quality miniature gear manufacturing. External spur type miniature brass (ASTM 858) gears with 12 teeth, 9.8 mm outside diameter and 5 mm face width were manufactured by WSEM. The research work was accomplished in four distinct experimental stages viz., preliminary, pilot, main and confirmation. The aim, scope and findings of each stage are progressively presented and discussed. In essence, the investigation found that it was possible to manufacture miniature gears to high quality by using WSEM. Gears up to DIN 5 quality with a good surface finish (1.2 µm average roughness) and satisfactory surface integrity were achieved. The results suggest that WSEM should be considered a viable alternative to conventional miniature gear manufacturing techniques and that in some instances it may even be superior. This work will prove useful to researchers and professionals in the field of miniature and micro-scale manufacturing and machining

Performance of pulsed-electrochemical honing and pulsed-electrochemical finishing in improving quality of bevel gears

This article presents a comparative study concerning performance of pulsed-electrochemical honing (PECH) and pulsed-electrochemical finishing (PECF) in straight bevel gear finishing. Performance of these processes were compared in terms of average percentage difference in the considered parameters of surface features of bevel gear namely average percentage differences in average surface roughness ‘PDRa’, maximum surface roughness ‘PDRmax’ and depth of surface roughness ‘PDRz’, micro-geometry (i.e. average percentage differences in single pitch error ‘PDfp’, adjacent pitch error ‘PDfu’, cumulative pitch error ‘PDFp’, and percentage difference in runout ‘PDFr’) and finishing productivity (i.e. material removal rate ‘MRR’). Microstructure and microhardness were also considered as measure for performance assessment. Observed results show PECH is proficient in simultaneously improving all the considered responses of bevel gears by more than 50% as compared to PECF. The PECH-finished gear additionally displayed unrivalled microstructure and better microhardness when contrasted with PECF-finished gear. These changes will upgrade the working-life and operating performance of the finished gear

Influence of MQL and hobbing parameters on microgeometry deviations and flank roughness of spur gears manufactured by MQL assisted hobbing

Abstract: Abstract Conventional cutting fluids used in gear hobbing have negative impacts on the environment and health of the machine operators thereby adversely affecting the sustainability of the gear hobbing process. This paper reports on MQL assisted hobbing (MQLAH) using environment friendly fatty alcohol-based lubricants to manufacture superior quality spur gears. Experimental investigation was conducted to study of influence of six parameters of MQLAH namely hob cutter speed, axial feed, depth of cut, lube flow rate, air pressure, and nozzle angle on microgeometry deviations, avg. and max. values of flank surface roughness, and material removal rate to identify their optimum ranges to manufacture better quality spur gears with maximum productivity. Deviations in total profile, lead, cumulative pitch and radial runout were used to evaluate microgeometry of the spur gears. It revealed that depth of cut has no considerable effect on the spur gear quality. It identified that higher value of hob cutter speed, lower value of axial feed, optimum values of lube flow rate as 100 ml/hr, nozzle angle as 30o, and air pressure in a range from 3-5 bar yield superior quality of spur gears by MQLAH

A comprehensive investigation on development of lightweight aluminium miniature gears by thermoelectric erosion machining process

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