The alternating movement of comber nipper balance shaft causes comber vibration, which is considered as the primary limitation for its velocity. First, optimal angular acceleration coefficients of nipper balance shaft...The alternating movement of comber nipper balance shaft causes comber vibration, which is considered as the primary limitation for its velocity. First, optimal angular acceleration coefficients of nipper balance shaft were set in this study to acquire theoretical limiting angular velocity. Second,the transmission input model of the input shaft was developed by adopting a numerical approximation method and by considering the Bézier curve as the motion curve of the input shaft. Hence, the motion of nipper balance shaft was controlled. The optimum transmission driver curve of the input shaft was obtained by contrasting the analyses of the actual angular acceleration of nipper balance shaft for each optimal coefficient. Experimental tests validated the results. The nipper balance shaft of the comber reduced comber vibration because the shaft adopted the controllable unit of transmission input.Our research sheds light on the application of controlled mechanisms in textile machines and provides a theoretical basis for increasing the velocity and decreasing the vibration or noise of the comber.展开更多
For a single cylinder engine, the total unbalanced inertial forces occur in the engine block, which results in engine’s vibration and deteriorated noise. In order to eliminate the unbalanced forces, counterweight and...For a single cylinder engine, the total unbalanced inertial forces occur in the engine block, which results in engine’s vibration and deteriorated noise. In order to eliminate the unbalanced forces, counterweight and primary balance shaft should be attached to the cylinder block so that engine durability and ride comfortability may be further improved. Traditionally one third of connecting rod assembly’s mass is treated as reciprocating mass, and two thirds as rotating mass when designing balance mechanism. In this paper, a new method based on the multibody dynamics simulation is introduced to separate the reciprocating mass and rotating mass of connecting rod assembly. The model consists of crankshaft, connecting rod, piston and the simulation is performed subsequently. According to the simulation results of the main bearing loads, the reciprocating mass and rotating mass are separated. Finally a new balance mechanism is designed and simulation results show that it completely balances inertial forces to improve the engine’s noise vibration and harshness performance.展开更多
基金National Basic Research Program of China(973 Program)(No.2010CB334711)Textile Vision Science&Education Fund,China(No.2012)National Natural Science Foundation of China(No.51205288)
文摘The alternating movement of comber nipper balance shaft causes comber vibration, which is considered as the primary limitation for its velocity. First, optimal angular acceleration coefficients of nipper balance shaft were set in this study to acquire theoretical limiting angular velocity. Second,the transmission input model of the input shaft was developed by adopting a numerical approximation method and by considering the Bézier curve as the motion curve of the input shaft. Hence, the motion of nipper balance shaft was controlled. The optimum transmission driver curve of the input shaft was obtained by contrasting the analyses of the actual angular acceleration of nipper balance shaft for each optimal coefficient. Experimental tests validated the results. The nipper balance shaft of the comber reduced comber vibration because the shaft adopted the controllable unit of transmission input.Our research sheds light on the application of controlled mechanisms in textile machines and provides a theoretical basis for increasing the velocity and decreasing the vibration or noise of the comber.
基金Supported by National Natural Science Foundation of China (No50575203)
文摘For a single cylinder engine, the total unbalanced inertial forces occur in the engine block, which results in engine’s vibration and deteriorated noise. In order to eliminate the unbalanced forces, counterweight and primary balance shaft should be attached to the cylinder block so that engine durability and ride comfortability may be further improved. Traditionally one third of connecting rod assembly’s mass is treated as reciprocating mass, and two thirds as rotating mass when designing balance mechanism. In this paper, a new method based on the multibody dynamics simulation is introduced to separate the reciprocating mass and rotating mass of connecting rod assembly. The model consists of crankshaft, connecting rod, piston and the simulation is performed subsequently. According to the simulation results of the main bearing loads, the reciprocating mass and rotating mass are separated. Finally a new balance mechanism is designed and simulation results show that it completely balances inertial forces to improve the engine’s noise vibration and harshness performance.
