In the case of a flexible rotor, it also means that not more than an acceptable magnitude of deflection occurs in the. Dynamic balancing of rotating machinery experiment technical. Rotating machinery rotor balancing the aim of rotor balancing is to achieve satisfactory running when installed on site. Frequently, a machine already in operation will need rebalancing or a new machine when. In this lab rotational equilibrium will be established in multiple experimental scenarios. Balancing of reciprocating and rotating masses study notes. Let 1,2,3and4 be the angles of these masses with the horizontal line ox, as shown in fig. In rotating machinery, mass imbalances are unavoidable and can lead to large vibrating forces and displacements. The aim of the experiment is to have a basic knowledge about the balanced and unbalanced rotating mass. For example, oil refining, the aerospace industry, the automotive industry, the cell phone industry, and the chemical production industry all use rotating machinery in the form of engines, turbines, compressors, and pumps. Circle the name of the person to whose report your group printouts will be attached. Let us now consider a single rigid rotating mass mounted in two supporting bearings and assume that the axis of rotation is horizontal. Dynamic balancing of rotating machinery in the field by e. The paper theory of unbalanced vibration, theory of balancing, determination of unbalanced mass is a meaty version of a lab report on engineering.
Especially, in the engineering world nowadays, where it is a common phenomenon to have engines and machines operating at high speeds. Of machine experiment 3 static and dynamic balancing at. This paper describes a method and portable equipment for balancing rotating machinery while running under normal operating conditions. There are a few causes that lead to unbalance of rotating machinery. The positions of the masses and the pivot point were altered in order to maintain rotational equilibrium. Demonstration of simple static and dynamic balancing of two, three and four rotating masses. Rotate the shaft to any angular position and leave it. Test rig description a rigid rotor can be corrected by making corrections in any two planes that can be selected. The unbalance creates unwanted inertial forces which cause increased. These calculations will be performed manually, by you first, then check by running the computer code dybal. Determine the masses to be added on the rotors in planes a and d at radius 40 mm which.
If it is statically balanced, then the shaft will retain its position. Balancing of several masses in different planes let there be a rotor revolving with a uniform angular velocity. Application notes static and dynamic balancing of rigid. When the rotor is statically balanced, then the center of mass lies on the axis of rotation a crosscheck. Universal coupling lab static dynamic rotation around a.
Rotating machinery rotor balancing lifetime reliability. Balancing of a single rotating mass by two masses rotating in different planes. Balancing of rotating masses in heavy industria l machines is very es sential to reduce the unpleasant and dangerous vibrati on. Piedmont chapter vibration institute training symposium 10. Body at state and dynamic state for the multiple plane comments on multiple planes recommendations the screws and bolt needed were out numbered. An equal mass, placed source of vibration in machines with by adding compensating masses to the at an angle of 180 to the unbalanced rotating parts. It is found out that the discs in the rotor test rig are balanced. This prevents wear and tear of the bearings and also of the equipment. Two illustrative examples have been demonstrated in order to understand the two di fferent techniques. Unit 4 balancing of rotating masses, dynamics of machines of vtu syllabus prepared by hareesha n gowda, asst. Play with objects on a teeter totter to learn about balance.
This product allows students to do experiments in balancing a rotating mass system and check their results against accepted theory. A rotating system of mass is in dynamic balance when the rotation does not produce any resultant centrifugal force or couple. Rotating a rod about an axis perpendicular to the rods long axis in activity 1. The positions of the masses and the pivot point were altered in order to maintain. Unbalance may be defined as uneven distribution of mass about the rotors rotating center line rcl bruel, 2000. Balancing of rotating masses report mechanics motion. Balancing act balance proportional reasoning torque. The system rotates without requiring the application of any external force or couple, other than that required to support its weight. The initial trial masses for balancing were then estimated. It means no more than an acceptable magnitude of vibration is caused by the unbalance remaining in the rotor.
Select two rods, one with black tape and the other with red tape. Balancing of several masses rotating in different planes static balancing. Balancing of rotating masses 2 theory three masses m1, m2 and m3 are rotating in three planes at radii r1 to r3 at angles. If the mass center of a component of mass m is rotating at an angular velocity at a. Predict how changing the positions of the masses on the plank will affect the motion of the plank. Dynamic balancing of rotating machinery in the field. Balancing of rotating masses body at single plane and multiple plane. Balancing is beneficial because it reduces vibrations and noise. Machine design lab section 8 static and dynamic balancing experiment experiment performed. To perform the experiment for static balancing on static balancing machine. A system of rotating masses is said to be in static balance if the combined mass centre of the system lies on the axis of rotation.
If the rotating and reciprocating parts are not properly balanced, the dynamic forces are set up. In modern dynamic balancing machines, indicating or recording devices are provided to show the position and extent of the unbalanced masses. Balancing of rotating masses rotation around a fixed axis. A system of rotating masses in dynamic balance when there does not exist any resultant centrifugal force as well as resultant couple. Single plane balancing laboratory experiment introduction components manufactured for use in rotating machinery are often not perfectly symmetric about their intended axis of rotation. Building 45, room g1 room with t4 launcher in it introduction if the mass centre of a component of mass m is rotating at an angular velocity. Whenever a certain mass is attached to a rotating shaft, it exerts some centrifugal force, whose effect is to bend the shaft and to produce vibrations in it. In general, there will be a resultant unbalanced force and couple. Because of this, it is found that an unbalance exists when the component is rotated. This document includes all lab reports on rotating the mass balancing. If balance attempt is not working as anticipated stop and think about what is going on. Balancing of several masses rotating in the same plane consider any number of masses say four of magnitude m1, m2, m3 and m4 at distances of r1, r2, r3 and r4 from the axis of the rotating shaft.
Therefore, the balancing of highspeed equipment is especially important. To ensure the most efficient and safest operation, a machine with rotating parts must be statically and. Since it is not possible to balance a couple with a single force, two balance masses. Bench top apparatus for experiments in balancing a rotating mass system, statically and dynamically. Feb 06, 2017 balancing of rotary masses in different transverse plane using two balancing masses, analytical approach if like this video please donate paytm 9422112581 up. In the first part you are balancing torque on an equal arm balance and the second part there is a rotating disc that you are trying to find the moment of inertia for. During static balancing, the component is not rotating, hence static. Dynamic balancing of rotating mass systems by calculation and vector diagrams triangle and polygon. The out of balance forces increase bearing loads, and introduce stresses in the rotor and. To help with balancing, it involves simply moving the centre of gravity to the centre of rotation. School of mechanical and aerospace engineering technical report on e2. The rotating component did not go out of balance by itself. Static balancing is done by holding the component at its axis, then compensating by removal or addition of mass for the heavy side of the component.
Balancing of rotating masses by kapal kertas on prezi. Field balancing is the process of correction mass in that plane only. Moreover, it describes static and dynamic balance, i. Sep 21, 2015 the tm1002 is an experiment that looks at balancing a rotating mass system, statically and dynamically. Rotational equilibrium is when the net torque acting on a system is equal to zero. Two balancing techniques ha ve been introduced in this chapter, namely, static and dynamic balan ce. The balancing masses are to be placed in planes x and y.
Dynamic and static balancing in heavy industrial machinery such as generators and motors can cause catastrophic failure, as well as noise and discomfort. The diagram below shows masses on two rotors in planes b and c. Remain skeptical during the balancing process and use the balancing procedure as a diagnostic tool. Balancing of rotating mass lab report 1 rotation mass. An equal and opposite force called centrifugal force acts radially outwards and is a disturbing force on the axis of rotation.
At the end of the lab session students should be able. Universal coupling lab static dynamic free download as pdf file. In heavy industrial machines such as gas turbines and electric generators, vibration can cause. Balancing of rotating masses 1 rotation around a fixed. A system of rotating masses is said to be in static balance if the combined mass centre of the system lies on the axis of. A direct and exact solution of the problem is offered, which makes it possible to. Universal coupling lab static dynamic rotation around. The forces generated due to an unbalance are proportional to the rotating speed of the rotor squared. Rcl is the axis the rotor would rotate if not constrained to the. These imbalances, which in many cases are unknown, can be corrected by a passive balancing system, which is more advantageous than an active balancing system in terms of complexity, as it does not require a sensoractuator system. Application notes static and dynamic balancing of rigid rotors.
Balancing of rotating masses 837 it may be noted that equation i represents the condition for static balance, but in order to achieve dynamic balance, equations ii or iii must also be satisfied. Lab manual static balancing on static balancing machine. To demonstrate a simple balancing technique for static balance. Basic understanding part ii in part i of this series basics of the static and dynamic balancing of rotating objects were discussed. Balancing of rotating masses static and dynamic balancing balancing of single rotating mass by balancing masses in same plane and in different planes. Types of balancing there are two forms of balancing. While it would not be impossible to construct a simple dynamic balancing rig in the home workshop, most of the problems involved in small machines can be dealt with by careful consideration of design, and. Rotational machinery is prevalent in the engineering field. Balancing is done by placing an identified mass at a given precise location on the rotor.
Predict how objects of various masses can be used to make a plank balance. The distance between the planes a and x is 100 mm, between x and y is 400 mm and between y and d is 200 mm. Balancing of rotating mass lab report 1 rotation mass scribd. To balance the rotor using 2 plane balancing a crosscheck. The balancing of rotating bodies is important to avoid vibration.
However, the balancing methods used here may require long time to get the correct masses for rectifying the unbalance. Frequently, a machine already in operation will need re balancing or a new machine when assembled at its permanent location will need balancing. Unit 6 introduction to balancing introduction to balancing. Balancing of several masses rotating in the same plane 4. The screws either nowhere to be seen, or different in dimension. When the rotor is completely balanced then on rotating it at different rpm, it will not undergo vibrations. Tecquipment static and dynamic balancing tm1002 ayva. Balancing of rotating and reciprocating systems in engine. In the case of a narrow wheel, balancing simply involves moving the center of gravity to the centre of rotation. Balancing of rotating masses rotation around a fixed. Test what youve learned by trying the balance challenge game.
If the balancing masses revolve at a radius of 100 mm, find their magnitudes and angular positions. The tm1002 is an experiment that looks at balancing a rotating mass system, statically and dynamically. Balancing of rotating masses when a mass moves along a circular path, it experiences a centripetal acceleration and a force is required to produce it. This report elucidates the importance of balancing rotating masses. To ensure the most efficient and safest operation, a machine with rotating. Many different industries utilize rotating machinery. This was done using a meter stick with masses suspended from it at various positions. Dynamics rotating balance experiment aerospace engineering.
1592 1149 33 307 20 98 1215 1504 204 1122 1232 1663 33 723 1480 921 1352 1447 98 484 812 1182 1005 903 887 899 225 922 1019 519 218 720 56 1167 1121 207 382 171 654