On the basis of deep investigation of locomotive traction gears manufactured at home and abroad , a variety of measures are putted forward to improve the driving load-bearing capacity and working life of our country&#...On the basis of deep investigation of locomotive traction gears manufactured at home and abroad , a variety of measures are putted forward to improve the driving load-bearing capacity and working life of our country's high-speed locomotive traction gears. The measures include the fol- lowing five aspects : optimally selecting the material and heat treatment process , optimally designing the tooth profile . reasonably choosing the manufacture accuracy and technique , optimally choosing the lubricant and the way of lubrication and seal , improving the dynamic feature of the gearing. In the respect of the tooth profile , a hob with optimal cutter angles is designed to make root thickness on the dangerous section as large as possible and the stress concentration as small as possible. Ad- dendum modification coefficient is optimized to minimize the maximum flash temperature in the course of meshing. Finally . finite element analysis method is used to calculate the deformation and the stress of teeth accurately. And on this basis , optimal profile correction and axial modification have been designed with regard to the start , continuious running and high speed travel of the loco- motive .展开更多
Axle-box bearings are crucial components of high-speed trains and operate in challenging conditions.As service mileage increases,these bearings are susceptible to various failures,posing a safety risk to high-speed tr...Axle-box bearings are crucial components of high-speed trains and operate in challenging conditions.As service mileage increases,these bearings are susceptible to various failures,posing a safety risk to high-speed train operations.Thus,it is crucial to examine the deployment methods of axle-box bearings.A dynamic model of axle-box bearings for high-speed trains with compound faults is constructed by setting up separate faults in two rows of double-row tapered roller bearings based on a single-fault model.The model's high accuracy in expressing compound faults is verified through corresponding experimental results.Then,the frequency domain diagram of system vibration response under varying rotational speed conditions is obtained,and the amplitude corresponding to the single frequency is extracted and analyzed to identify the optimal rotational speed band for composite fault diagnosis.Finally,the optimal speed band is analyzed under different faults,different load sizes,and different composite fault types.It can be concluded that the determination of the optimal speed band is solely influenced by the composite fault type and is independent of the fault and load sizes.Finally,it is concluded that the energy proportion of faults in different positions changes periodically with the change in speed,and this phenomenon is not affected by the fault sizes or load magnitude.展开更多
In this paper, we present a new fruit fly optimization algorithm with the adaptive step for solving unconstrained optimization problems, which is able to avoid the slow convergence and the tendency to fall into local ...In this paper, we present a new fruit fly optimization algorithm with the adaptive step for solving unconstrained optimization problems, which is able to avoid the slow convergence and the tendency to fall into local optimum of the standard fruit fly optimization algorithm. By using the information of the iteration number and the maximum iteration number, the proposed algorithm uses the floor function to ensure that the fruit fly swarms adopt the large step search during the olfactory search stage which improves the search speed;in the visual search stage, the small step is used to effectively avoid local optimum. Finally, using commonly used benchmark testing functions, the proposed algorithm is compared with the standard fruit fly optimization algorithm with some fixed steps. The simulation experiment results show that the proposed algorithm can quickly approach the optimal solution in the olfactory search stage and accurately search in the visual search stage, demonstrating more effective performance.展开更多
文摘On the basis of deep investigation of locomotive traction gears manufactured at home and abroad , a variety of measures are putted forward to improve the driving load-bearing capacity and working life of our country's high-speed locomotive traction gears. The measures include the fol- lowing five aspects : optimally selecting the material and heat treatment process , optimally designing the tooth profile . reasonably choosing the manufacture accuracy and technique , optimally choosing the lubricant and the way of lubrication and seal , improving the dynamic feature of the gearing. In the respect of the tooth profile , a hob with optimal cutter angles is designed to make root thickness on the dangerous section as large as possible and the stress concentration as small as possible. Ad- dendum modification coefficient is optimized to minimize the maximum flash temperature in the course of meshing. Finally . finite element analysis method is used to calculate the deformation and the stress of teeth accurately. And on this basis , optimal profile correction and axial modification have been designed with regard to the start , continuious running and high speed travel of the loco- motive .
基金National Natural Science Foundation of China,Grant/Award Numbers:12032017,12002221Key Scientific Research Projects of China Railway Group,Grant/Award Number:N2021J032+1 种基金S&T Program of Hebei,Grant/Award Number:21567622HNational Scholarship Council of China。
文摘Axle-box bearings are crucial components of high-speed trains and operate in challenging conditions.As service mileage increases,these bearings are susceptible to various failures,posing a safety risk to high-speed train operations.Thus,it is crucial to examine the deployment methods of axle-box bearings.A dynamic model of axle-box bearings for high-speed trains with compound faults is constructed by setting up separate faults in two rows of double-row tapered roller bearings based on a single-fault model.The model's high accuracy in expressing compound faults is verified through corresponding experimental results.Then,the frequency domain diagram of system vibration response under varying rotational speed conditions is obtained,and the amplitude corresponding to the single frequency is extracted and analyzed to identify the optimal rotational speed band for composite fault diagnosis.Finally,the optimal speed band is analyzed under different faults,different load sizes,and different composite fault types.It can be concluded that the determination of the optimal speed band is solely influenced by the composite fault type and is independent of the fault and load sizes.Finally,it is concluded that the energy proportion of faults in different positions changes periodically with the change in speed,and this phenomenon is not affected by the fault sizes or load magnitude.
文摘In this paper, we present a new fruit fly optimization algorithm with the adaptive step for solving unconstrained optimization problems, which is able to avoid the slow convergence and the tendency to fall into local optimum of the standard fruit fly optimization algorithm. By using the information of the iteration number and the maximum iteration number, the proposed algorithm uses the floor function to ensure that the fruit fly swarms adopt the large step search during the olfactory search stage which improves the search speed;in the visual search stage, the small step is used to effectively avoid local optimum. Finally, using commonly used benchmark testing functions, the proposed algorithm is compared with the standard fruit fly optimization algorithm with some fixed steps. The simulation experiment results show that the proposed algorithm can quickly approach the optimal solution in the olfactory search stage and accurately search in the visual search stage, demonstrating more effective performance.
