TAILIEUCHUNG - Primer on Dynamic Balancing “Causes, Corrections and Consequences”

When man invented the wheel, he very quickly learned that if it wasn’t completely round and if it didn’t rotate evenly about it’s central axis, then he had a problem! The wheel would vibrate, causing damage to itself and it’s support mechanism and in severe cases, be unusable. As the task of manufacturing a replacement was so huge and time consuming, a method had to be found to minimize the problem. Research showed that the wheel and its shaft had to be in a state of balance, . the mass had to be evenly distributed about the rotating centerline so that the resultant vibration was at a minimum. This. | EnTEKJRQ tNTEftNATiONAL Primer on Dynamic Balancing Causes Corrections and Consequences Presented at MainTech South 98 2 December 1998 By Jim Lyons International Sales Manager IRD Balancing Div. EntekIRD International Page 1 Abstract When man invented the wheel he very quickly learned that if it wasn t completely round and if it didn t rotate evenly about it s central axis then he had a problem The wheel would vibrate causing damage to itself and it s support mechanism and in severe cases be unusable. As the task of manufacturing a replacement was so huge and time consuming a method had to be found to minimize the problem. Research showed that the wheel and its shaft had to be in a state of balance . the mass had to be evenly distributed about the rotating centerline so that the resultant vibration was at a minimum. This had to be achieved during the manufacturing process and perhaps just as importantly as wear occurred so that maximum service life could be achieved from the system. Modern man still suffers from the same problem - only now the problem is amplified. As machines get bigger and go faster the effect of the unbalance is much more severe. A level of unbalance that is acceptable at a low speed is completely unacceptable at a higher speed. This is because the unbalance condition produces centrifugal force which increases as the speed increases. In fact the force formula page 1-6 shows that the force caused by unbalance increases by the square of the speed. If the speed is doubled the force quadruples if the speed is tripled the force increases by a factor of nine It is the force that causes vibration of the bearings and surrounding structure. Prolonged exposure to the vibration results in damage and increased downtime of the machine. Vibration can also be transmitted to adjacent machinery affecting their accuracy or performance. Identifying and correcting the mass distribution and thus minimizing the force and resultant vibration is the technique

• Cơ khí - Chế tạo máy
• Dynamic Balancing
• Causes
• Corrections
• Consequences
• Principal Inertia Axis
• Geometric Centerline
• cơ khí
• cân bằng tĩnh
• cân bằng động
• mặt phẳng quay
• vật liệu
• BMC Bioinformatics
• Metabolic models
• Flux variability analysis
• High performance computing
• Systems biology