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This paper presents an optimization method for gear processes; through this method, the most worth optimized processes can be obtained and optimized, thus improving the reliability and supportability of gear products. Firstly, the POPN (Process Optimization Priority Number) analysis method considering the current process level and the process impro...
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... Recently, ultra-high strength steels have attracted an increase attention to prepare high-performance gears in helicopter transmission system to confront the complex and severe environment, owing to their superior mechanical properties (e.g., high hardness and high toughness) [1,3]. Grinding as the final and crucial manufacturing processes was widely used to ensure the machining accuracy and surface integrity [4,5]. ...
Super high-strength steel has an important demand in manufacturing key components inside gear transmission systems of heavy-duty helicopter owing to its superior comprehensive mechanical property. However, the high-performance machining of super high-strength steel is confronted with great challenges owing to the high cutting force, serious tool wear, and impoverished machining quality. Comparative trials in grinding ultra-high strength steel under conventional grinding (CG) and ultrasonic vibration-assisted grinding (UVAG) processes were conducted with white alumina (WA) and microcrystalline alumina (MA) wheels. Grinding performances, including grinding forces, force ratio, ground surface quality, and abrasive wheel morphologies, were discussed in detail. Experimental results show that the separation property between wheels and workpiece in UVAG process contributes to alter the material removal process, reducing the chip clogging and adhesion. In addition, the micro-fracture of abrasive grains can effectively improve the self-sharpening ability of abrasive wheels. UVAG possesses a shorter grinding scratch owing to the ultrasonic vibration than that of CG, which is beneficial to improve machining quality under the same wheel. Meanwhile, in comparison of WA wheels, MA wheels have the narrower grinding marks and better surface quality, which is due to the sharp edges produced by its higher strength, toughness, and excellent self-sharpening.
... Recently, ultra-high strength steels have attracted an increase attention to prepare high-performance gears in helicopter transmission system to confront the complex and severe environment, owing to their superior mechanical properties (e.g. high hardness, high toughness, etc) [1][2][3]. Grinding as the nal and crucial manufacturing processes was widely used to ensure the machining accuracy and surface integrity [4,5]. However, the ultra-high strength steels after quenched treatments have the dispersed reinforced particles, leading to the di cult-to-machine properties on the near-layer surface of workpiece [6,7]. ...
Super high-strength steel has an important demand in manufacturing key components inside gear transmission systems of heavy-duty helicopter owing to its superior comprehensive mechanical property. However, the high-performance machining of super high-strength steel is confronted with great challenges owing to the high cutting force, serious tool wear, and impoverished machining quality. Comparative trials in grinding ultra-high strength steel under conventional grinding (CG) and ultrasonic vibration-assisted grinding (UVAG) processes was conducted with white alumina (WA) and microcrystalline alumina (MA) wheels. Grinding performances, including grinding forces, force ratio, ground surface quality, and abrasive wheel morphologies were discussed in detail. Experimental results show that the separation property between wheels and workpiece in UVAG process contributes to alter the material removal process, reducing the chip clogging and adhesion. In addition, the micro-fracture of abrasive grains can effectively improve the self-sharpening ability of abrasive wheels. UVAG possesses a shorter grinding scratch owing to the ultrasonic vibration than that of CG, which is beneficial to improve machining quality under the same wheel. Meanwhile, in comparison of WA wheels, MA wheels have the narrower grinding marks and better surface quality, which is due to the sharp edges produced by its higher strength, toughness and excellent self-sharpening.
... thrust-to-weight ratio, reliability and service life) in modern aerospace, ship and automobile industry sectors. Gears are the key components of the abovementioned transmission systems; hence, their surface quality plays a crucial influence on the service performance of the whole system [1][2][3][4]. At present, the grinding process is usually applied as the final procedure to raise the dimension accuracy and surface integrity of gears [5,6]. ...
Composite manufacturing with multiple energy fields is an important source of processing technology innovation. In this work, comparative experiments on the conventional grinding and ultrasonic vibration–assisted grinding (UVAG) of hardened GCr15 steel were conducted with white alumina (WA) wheel. The grinding wheel wear patterns and chips were characterised. In addition, grinding force, force ratio and ground surface quality were investigated to evaluate wheel performance. Results illustrate that the interaction between abrasive grains and workpiece in UVAG has the characteristics of high frequency and discontinuity. The wear property of abrasive grains is changed, and the grinding force is decreased because the generation of microfracture in abrasive grains improves the self-sharpening of the grinding wheel. Good surface quality is obtained. The surface roughness is reduced by up to 18.96%, and the number of defects on the machined surface is reduced through the superior reciprocating ironing of UVAG. Accordingly, WA wheel performance is improved by UVAG.
... In recent years, the demands of mechanical transmission systems have increased to meet the higher performance requirements (e.g., thrust-to-weight ratio, reliability, and service life) in modern aerospace, ship, and automobile industry sectors. The surface quality of gears, as the key components of the above mentioned transmission systems, plays a crucial in uence on the service performance of whole systems [1][2][3][4]. At present, the grinding process is usually applied as the nal procedure to raise the dimension accuracy and surface integrity of gears [5][6][7]. ...
Composite manufacturing with multiple energy fields is an important source of processing technology innovation. In this work, comparative experiments on the conventional grinding (CG) and ultrasonic vibration-assisted grinding (UVAG) of hardened GCr15 steel were conducted with WA wheel. The grinding wheel wear patterns and chips were characterized. In addition, grinding force, force ratio, and ground surface quality were investigated to evaluate wheel performance. Results illustrate that the interaction between abrasive grains and workpiece in UVAG process has the characteristics of high frequency and discontinuity. The wear property of abrasive grains is changed and the grinding force is decreased because the generation of micro-fracture in abrasive grains improves the grinding wheel self-sharpening. Better surface quality is obtained, the surface roughness is reduced by up to 18.96%, and the number of defects on the machined surface is reduced through the superior reciprocating ironing of UVAG. Accordingly, WA wheel performance is improved by UVAG.
... When researching the interaction of various factors and the influence degree of various factors on TSCS when they exist at the same time, this paper uses the Taguchi method (TM). The TM has been widely used for the design and analysis of various engineering fields, such as gear manufacturing processes [13], chemical industry [14], soil [15] and energy [16], and it has been demonstrated to be a powerful tool due to its simplicity and robustness [17]. Through the TM, within the specified level range, the optimal level combination of influence factors can also be obtained to determine the optimal TPD grade, ME and LCM quantity in order to obtain a relatively minimum TSCS. ...
Based on the three-dimensional (3D) finite element method (FEM) and Taguchi method (TM), this paper analyzes the tooth surface contact stress (TSCS) of spur gears with three different influence factors: tooth profile deviations (TPD), meshing errors (ME) and lead crowning modifications (LCM), especially researching and analyzing the interactions between TPD, ME and LCM and their degree of influence on the TSCS. In this paper, firstly, a 3D FEM model of one pair of engaged teeth is modeled and the mesh of the contact area is refined by FEM software. In the model, the refined area mesh and the non-refined area mesh are connected by multi-point constraint (MPC); at the same time, in order to save the time of the FEM solution on the premise of ensuring the solution’s accuracy, the reasonable size of the refined area is studied and confirmed. Secondly, the TSCS analyses of gears with one single influence factor (other factors are all ideal) are carried out. By inputting the values of different levels of one single factor into the FEM model, especially using the real measurement data of TPD, and conducting the TSCS analysis under different torques, the influence degree of one single factor on TSCS is discussed by comparing the ideal model, and it is found that when the influence factors exist alone, each factor has a great influence on the TSCS. Finally, through TM, an orthogonal test is designed for the three influence factors. According to the test results, the interactions between the influence factors and the influence degree of the factors on the TSCS are analyzed when the three factors exist on the gear at the same time, and it is found that the TPD has the greatest influence on the TSCS, followed by the lead crowning modified quantity. The ME is relatively much small, and there is obvious interaction between ME and LCM. In addition, the optimal combination of factor levels is determined, and compared with the original combination of a gear factory, we see that the contact fatigue performance of the gear with the optimal combination is much better. The research of this paper has a certain reference significance for the control of TPD, ME and LCM when machining and assembling the gears.
... However, the production of high-quality gears is often jeopardized by some flaws in the manufacturing processes and unfavorable conditions [3]. A typical gear manufactur-ing process consists of seven stages: structural design stage, material selection stage, forging stage, roughing stage, heat treatment stage, and finishing stage and testing stage [4]. Out of these seven stages, the heat treatment stage is considered critical as the gear's load-carrying capacity largely depends on the type of heat treatment carried [5]. ...
The heat treatment process (HTP) is crucial in the manufacturing of any component, also the activities concerned with the heat treatment process are often subject to hazards. When the data related to industrial accidents are analyzed, it is identified that most of the industrial accidents have occurred because of HTP. Considering this, this research work intends to identify, analyze, and prioritize the activities carried in the HTP based on the nature of hazards. To identify the various activities carried out in the HTP and to understand the nature of hazards involved, a study was carried out in gear manufacturing company located in western Tamilnadu, India. Eighteen activities carried in the HTP are identified. Then, the total interpretive structural modeling (TISM) method is used to analyze the various activities. In the TISM method, the obtained results are generally arranged in hierarchical order, and the activity at the bottom of the hierarchy need to be addressed immediately. Next, MICMAC analysis is performed to understand the relationship between the activities. In our case, the activating finishing process, tempering, vacuum hardening process, and nitriding case hardening process are at the bottom level, and these activities need to be addressed in a short time. In MICMAC analysis, out of the 18 activities, 4 comes under the autonomous category, 3 comes under the dependent category, 6 comes under the linkage category, and 5 comes under the independent category. Based on the results obtained, some practical managerial implications are suggested for the mangers and practitioners involved in the heat treatment process.
... In paper [4] authors include Pareto optimisation technique to allow for multicriteria production optimisation. The work [5] focuses on researching different methods of optimisation and evaluating their strong and weak sides. ...
... f(x1,x2,x3,x4) = a1*x1 + a2*x2 + a3*x3 + a4*x4 (5) It is known that "Amount of energy produced" and "Hydraulic unit operation time" parameters positively affect productivity, while "Hydraulic unit wear degree" and "The break time duration" worsen these parameters. Thus, the decision maker can assign the following coefficients: a1 = 5; a2 = -1; a3 = 3; a4 = -2, taking into account knowledge of the subject area. ...
O presente estudo propõe um modelo de apoio à tomada de decisão, que combina FMEA e Hesitant Fuzzy-TOPSIS, para apoiar a avaliação e priorização de riscos em processos industriais. O modelo computacional foi implementado no software Microsoft Excel ® e aplicado ao processo de fabricação de chicotes elétricos de uma empresa nacional. A aplicação teve como objetivo principal testar e avaliar o comportamento do modelo em uma situação real de avaliação de riscos. Os resultados da aplicação sugerem que o modo de falha "Decape-comprimento menor que o especificado" representa o maior nível de risco do processo em questão, pois pode provocar perda parcial ou total da função primária do chicote elétrico. Os resultados indicam que o modelo proposto se apresenta como uma alternativa eficaz para apoiar a avaliação e priorização de riscos. As saídas do modelo fornecem subsídios para a formulação de planos de ação com base no nível de risco dos modos de falhas. Outras contribuições deste estudo consistem em: melhorar a discriminação dos níveis de risco em relação ao FMEA tradicional; suportar decisões em grupo em situação de incerteza e hesitação; e permitir aos decisores o uso de expressões linguísticas para avaliar os critérios e modos de falhas.
