The 4-lobe aluminum alloy helical surface rotors are widely applied in industry,such as superchargers.Generally,the conventional manufacturing processes of aluminum alloy helical surface are time consuming and costly....The 4-lobe aluminum alloy helical surface rotors are widely applied in industry,such as superchargers.Generally,the conventional manufacturing processes of aluminum alloy helical surface are time consuming and costly.To make the manufacturing processes more flexible and economical,the forward hot extrusion process is proposed to form the 4-lobe aluminum alloy helical surface rotors.In this work,we implement both simulations and experiments to the forming process of the helical surface,of which the material is 6063 aluminum alloy.The forward hot extrusion process is simulated with finite element method in DEFORM-3D.Based on the simulation method,the influences of different extrusion parameters,such as extrusion temperature,extrusion speed and extrusion ratio,on the extrusion process are studied.According to the numerical simulation results,the optimal case is chosen to carry out the experiment.Furthermore,the experimental results show that the surface is smooth;the toothed fill is full;the twist angle in the length direction is evenly distributed;the value of twist angle is roughly in line with the design angle,which is mainly due to the modified die structure,having a positive and significant effect on the increment of twist angle.Therefore,the twist angle has an increase of about 76%,which verifies the modified die structure.展开更多
The work presented in this paper focuses on improving coal loading performance of shear drum.Employing the similarity theory,we carried out a dimensional analysis of the correlation parameters which influence coal loa...The work presented in this paper focuses on improving coal loading performance of shear drum.Employing the similarity theory,we carried out a dimensional analysis of the correlation parameters which influence coal loading performance of shear drum.On the basis of similarity criterion,proportional relationship between the model and the prototype was taken on the condition of taking 1/3 as the similarity coefficient.Besides taking 1600 mm drum as the prototype,four helical angle models of shearer drums(15°,18°,21°,24°) were developed.Simultaneously,based on an established cutting test-bed,coal loading performance tests for the four drums were carried out at the same drum rotational and haulage speeds.After analyzing the data of coal-loading performance and torque,we concluded that:both the coal loading performance and torque vary along the track of the parabola with the opening side facing downwards;the best coal loading performance arises when the helical angle is at 19.3°,while the biggest torque arises at 22.1°;and the coal loading performance had nonlinear relationship with the torque.展开更多
基金Project(zzyjkt2014-09)supported by the National Key Laboratory of High Performance and Complex Manufacturing,ChinaProject(2015GK3006)supported by Key R&D Program of Science and Technology Department of Hunan Province,China
文摘The 4-lobe aluminum alloy helical surface rotors are widely applied in industry,such as superchargers.Generally,the conventional manufacturing processes of aluminum alloy helical surface are time consuming and costly.To make the manufacturing processes more flexible and economical,the forward hot extrusion process is proposed to form the 4-lobe aluminum alloy helical surface rotors.In this work,we implement both simulations and experiments to the forming process of the helical surface,of which the material is 6063 aluminum alloy.The forward hot extrusion process is simulated with finite element method in DEFORM-3D.Based on the simulation method,the influences of different extrusion parameters,such as extrusion temperature,extrusion speed and extrusion ratio,on the extrusion process are studied.According to the numerical simulation results,the optimal case is chosen to carry out the experiment.Furthermore,the experimental results show that the surface is smooth;the toothed fill is full;the twist angle in the length direction is evenly distributed;the value of twist angle is roughly in line with the design angle,which is mainly due to the modified die structure,having a positive and significant effect on the increment of twist angle.Therefore,the twist angle has an increase of about 76%,which verifies the modified die structure.
基金provided by the National Natural Science Foundation of China (No.51005232)the Postdoctoral Science Foundation of China (No.20100481176)
文摘The work presented in this paper focuses on improving coal loading performance of shear drum.Employing the similarity theory,we carried out a dimensional analysis of the correlation parameters which influence coal loading performance of shear drum.On the basis of similarity criterion,proportional relationship between the model and the prototype was taken on the condition of taking 1/3 as the similarity coefficient.Besides taking 1600 mm drum as the prototype,four helical angle models of shearer drums(15°,18°,21°,24°) were developed.Simultaneously,based on an established cutting test-bed,coal loading performance tests for the four drums were carried out at the same drum rotational and haulage speeds.After analyzing the data of coal-loading performance and torque,we concluded that:both the coal loading performance and torque vary along the track of the parabola with the opening side facing downwards;the best coal loading performance arises when the helical angle is at 19.3°,while the biggest torque arises at 22.1°;and the coal loading performance had nonlinear relationship with the torque.
