Static and Dynamics balancing
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The document discusses static and dynamic balancing in the context of machine dynamics. Static balance occurs when an object's center of gravity is aligned with its axis of rotation, while dynamic balancing involves correcting imbalances in rotating parts using electronic measurement. A problem is presented to determine the relative positions of pulleys and the dynamic forces on bearings for a rotating shaft with specified pulley masses and positions.
Static and Dynamics balancing
- 1. S. B. Jain Institute Of Technology, Management & Research Near Jain International School, Katol Road, Nagpur-441501 Static and Dynamics balancing NAME: AVINASH P. BARVE SUBJECT : DYNAMIC OF MACHINE TOPIC: STATIC AND DYNAMICS BALANCING (SELF LEARNING) SECTION/SEM./YEAR : B/6TH /3RD ROLL NO.: 6216
- 2. Balance....by definition The stability resulting from the equalization of opposing forces.
- 3. What is Static Balance? Static balance occurs when the centre of gravity of an object is on the axis of rotation. This allows the object to remain stationary, with the axis horizontal, without the application of any braking force. Static balance has no tendency to rotate due to the force of gravity. Static Balance is when the weight of the wheel and tire assembly is distributed equally around the axis of the wheel rotation. If static Balance exists the wheel will have no tendency to rotate.
- 4. HOW DO YOU STATIC BALANCE THIS WHEEL? Heavy Area Rotates to Bottom IS THIS WHEEL IN STATIC BALANCE?
- 5. Dynamic Balancing Dynamic balancing definition: “Dynamic balancing is a way of balancing machines by rotating parts quickly and measuring the imbalance using electronic equipment. The imbalance measured can then be corrected by adding or subtracting weight from the rotating parts until the vibration is reduced.”
- 6. Problem:- A shaft is supported in bearings 1.8 m apart and projects 0.45 m beyond bearings at each end. The shaft carries three pulleys one at each end and one at the middle of its length. The mass of end pulleys is 48 kg and 20 kg and their centre of gravity are 15 mm and 12.5 mm respectively from the shaft axis. The centre pulley has a mass of 56 kg and its centre of gravity is 15 mm from the shaft axis. If the pulleys are arranged so as to give static balance, determine : 1. relative angular positions of the pulleys, and 2. dynamic forces produced on the bearings when the shaft rotates at 300 r.p.m. Solution. Given : mA= 48 kg ; mC= 20 kg ; rA= 15 mm = 0.015 m ; rC= 12.5 mm =0.0125 m ; mB= 56 kg ; rB= 15 mm = 0.015 m ; N = 300 r.p.m. or ω= 2 π × 300/60 = 31.42 rad/s Relative angular position of the pulleys The position of the shaft and pulleys is shown in Fig. 21.13 (a). Let mLand mM= Mass at the bearings L and M, and rL and rM= Radius of rotation of the masses at L and M respectively. Assuming the plane of bearing L as reference plane, the data may be tabulated as below :
- 8. Dynamic forces at the two bearings
- 11. Thank You