Transgression networks in metropolitan centers need to supply a large quantity of power in a reliable manner to vital loads that are located within. A transmission network supplying such an important area must have a ...Transgression networks in metropolitan centers need to supply a large quantity of power in a reliable manner to vital loads that are located within. A transmission network supplying such an important area must have a high standard of reliability. Therefore, those transmission systems require a special form of redundancy in order to prevent sustained outages after severe contingencies such as multiple faults. This paper outlines different forms of redundancy, and the fundamental options for designing a metropolitan network based on different forms of redundancy are illustrated. Relative merits and drawbacks of network designs based on each form of redundancy are also shown.展开更多
Associated dynamic performance of the clamping force control valve used in continuously variable transmission （CVT） is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dy...Associated dynamic performance of the clamping force control valve used in continuously variable transmission （CVT） is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dynamic model is set up by means of mechanism analysis. For the purpose of checking the validity of the modeling method, a prototype workpiece of the valve is manufactured for comparison test, and its simulation result follows the experimental result quite well. An associated performance index is founded considering the response time, overshoot and saving energy, and five structural parameters are selected to adjust for deriving the optimal associated performance index. The optimization problem is solved by the genetic algorithm （GA） with necessary constraints. Finally, the properties of the optimized valve are compared with those of the prototype workpiece, and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.展开更多
One notable transmission characteristic of an elliptic gear mechanism is that the driven gear will rotate at varying speed according to a given rule when the drive gear rotates at a uniform speed, which can just meet ...One notable transmission characteristic of an elliptic gear mechanism is that the driven gear will rotate at varying speed according to a given rule when the drive gear rotates at a uniform speed, which can just meet some special requirements that a common mechanism cannot meet. It is important for the design of special mechanisms. In this paper, the transmission characteristic of an elliptic gear mechanism was analyzed and the design method was researched. The application of the elliptic gear used in the grooved gearing mechanism was designed and the validity was proved.展开更多
The great diversity of dedicated hybrid transmissions(DHTs)requires a method to identify solutions among all potential concepts involved in each structure.Therefore,a DHT synthesis tool is developed on the basis of ge...The great diversity of dedicated hybrid transmissions(DHTs)requires a method to identify solutions among all potential concepts involved in each structure.Therefore,a DHT synthesis tool is developed on the basis of general transmission synthesis.In the first synthesis step,transmission structures are generated with only conventional functions such as driving with only the internal combustion engine.Electric machines are then installed in the transmissions to achieve further hybrid functions,including boosting,eCVT and electric driving modes.The number of generated transmission concepts increases exponentially with each synthesis step.Various evaluations are carried out successively to identify the most suitable DHT concepts among the many possible solutions.The generated DHT concepts are evaluated in terms of structural feasibility,driving modes,drivability and load factors on transmission components.An example of DHT synthesis involving planetary gear sets is explained in detail.The best five DHT structures are identified out of more than 120 billion solutions.展开更多
文摘Transgression networks in metropolitan centers need to supply a large quantity of power in a reliable manner to vital loads that are located within. A transmission network supplying such an important area must have a high standard of reliability. Therefore, those transmission systems require a special form of redundancy in order to prevent sustained outages after severe contingencies such as multiple faults. This paper outlines different forms of redundancy, and the fundamental options for designing a metropolitan network based on different forms of redundancy are illustrated. Relative merits and drawbacks of network designs based on each form of redundancy are also shown.
基金Key Science-Technology Foundation of Hunan Province, China (No. 05GK2007).
文摘Associated dynamic performance of the clamping force control valve used in continuously variable transmission （CVT） is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dynamic model is set up by means of mechanism analysis. For the purpose of checking the validity of the modeling method, a prototype workpiece of the valve is manufactured for comparison test, and its simulation result follows the experimental result quite well. An associated performance index is founded considering the response time, overshoot and saving energy, and five structural parameters are selected to adjust for deriving the optimal associated performance index. The optimization problem is solved by the genetic algorithm （GA） with necessary constraints. Finally, the properties of the optimized valve are compared with those of the prototype workpiece, and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.
文摘One notable transmission characteristic of an elliptic gear mechanism is that the driven gear will rotate at varying speed according to a given rule when the drive gear rotates at a uniform speed, which can just meet some special requirements that a common mechanism cannot meet. It is important for the design of special mechanisms. In this paper, the transmission characteristic of an elliptic gear mechanism was analyzed and the design method was researched. The application of the elliptic gear used in the grooved gearing mechanism was designed and the validity was proved.
文摘The great diversity of dedicated hybrid transmissions(DHTs)requires a method to identify solutions among all potential concepts involved in each structure.Therefore,a DHT synthesis tool is developed on the basis of general transmission synthesis.In the first synthesis step,transmission structures are generated with only conventional functions such as driving with only the internal combustion engine.Electric machines are then installed in the transmissions to achieve further hybrid functions,including boosting,eCVT and electric driving modes.The number of generated transmission concepts increases exponentially with each synthesis step.Various evaluations are carried out successively to identify the most suitable DHT concepts among the many possible solutions.The generated DHT concepts are evaluated in terms of structural feasibility,driving modes,drivability and load factors on transmission components.An example of DHT synthesis involving planetary gear sets is explained in detail.The best five DHT structures are identified out of more than 120 billion solutions.
