Three drums with different helical angles （15°, 20°, and 25°） were developed to investigate improved loading performance of the shearer drum. Nine trials were performed at different drum rotation spee...Three drums with different helical angles （15°, 20°, and 25°） were developed to investigate improved loading performance of the shearer drum. Nine trials were performed at different drum rotation speeds （80, 100, and 120 r/min） and different haulage speeds （1.5, 2.0, and 2.5 m/min） in an orthogonal test design. Loaded coal quantity and cutting power of the drum were the responses measured under the dif- ferent conditions. The effect of the parameters was determined by means of the extreme difference method. The significance of the effects was determined by analysis of variance. The results indicate that the effect from changes in the helical vane on loading performance of the drum is the largest in magnitude. The haulage speed has the least affect on loading performance. The helical angle has the least affect on cutting power of the drum. Haulage speed has the largest affect on the cutting power of the drum. 2011 Published by Elsevier B.V. on behalf of China University of Mining ＆ Technology.展开更多
Towing tractor drivelines are lightly damped non-linear systems. Interactions between components can cause dynamic behavors such as gear gap impact in gear transmissions, shuffle and clonk phenomena in driveline. The ...Towing tractor drivelines are lightly damped non-linear systems. Interactions between components can cause dynamic behavors such as gear gap impact in gear transmissions, shuffle and clonk phenomena in driveline. The torsional vibration of driveline has an important effect on grand engineering vehicle vibration and noise. Through analyzing torsional vibration equations of driveline, torsional vibration model of driveline is developed by using Matlab/Simulink software, Shuffle and clonk phenomena are observed in torsional vibration. The modeling method of analysizing driveline torsional vibration can be used to research and improve similar engineering vehicle driveline behavors.展开更多
While modeling a power supply system for an electric railway traction, knowing equivalent circuits of locomotives supplied this way is an essential issue. In alternating current traction, it is important to diagnose i...While modeling a power supply system for an electric railway traction, knowing equivalent circuits of locomotives supplied this way is an essential issue. In alternating current traction, it is important to diagnose inter alia processes taking place in transformers installed on electric vehicles. This article presents specific phenomena occurring during the work of mono-phase, multi-winding, multisystem （systems AC： 50 Hz, 16.7 Hz） laboratory traction transformer. It also shows difficulties encountered during the process of identifying multi-port equivalent scheme＇s elements of the described device, in which a construction defect occurs.展开更多
基金support for this work was provided by the National Natural Science Foundation of China (No. 51005232)the China Postdoctoral Science Foundation (No. 20100481176)
文摘Three drums with different helical angles （15°, 20°, and 25°） were developed to investigate improved loading performance of the shearer drum. Nine trials were performed at different drum rotation speeds （80, 100, and 120 r/min） and different haulage speeds （1.5, 2.0, and 2.5 m/min） in an orthogonal test design. Loaded coal quantity and cutting power of the drum were the responses measured under the dif- ferent conditions. The effect of the parameters was determined by means of the extreme difference method. The significance of the effects was determined by analysis of variance. The results indicate that the effect from changes in the helical vane on loading performance of the drum is the largest in magnitude. The haulage speed has the least affect on loading performance. The helical angle has the least affect on cutting power of the drum. Haulage speed has the largest affect on the cutting power of the drum. 2011 Published by Elsevier B.V. on behalf of China University of Mining ＆ Technology.
文摘Towing tractor drivelines are lightly damped non-linear systems. Interactions between components can cause dynamic behavors such as gear gap impact in gear transmissions, shuffle and clonk phenomena in driveline. The torsional vibration of driveline has an important effect on grand engineering vehicle vibration and noise. Through analyzing torsional vibration equations of driveline, torsional vibration model of driveline is developed by using Matlab/Simulink software, Shuffle and clonk phenomena are observed in torsional vibration. The modeling method of analysizing driveline torsional vibration can be used to research and improve similar engineering vehicle driveline behavors.
文摘While modeling a power supply system for an electric railway traction, knowing equivalent circuits of locomotives supplied this way is an essential issue. In alternating current traction, it is important to diagnose inter alia processes taking place in transformers installed on electric vehicles. This article presents specific phenomena occurring during the work of mono-phase, multi-winding, multisystem （systems AC： 50 Hz, 16.7 Hz） laboratory traction transformer. It also shows difficulties encountered during the process of identifying multi-port equivalent scheme＇s elements of the described device, in which a construction defect occurs.
