If a rotor is balanced on a low speed balancing machine assuming it is rigid and then in service becomes flexible, then unbalance, and thus high vibration, will be the result. Us20263659a1 passive dynamic inertial rotor balance. Static and dynamic balancing of helicopter tail rotor. Basic methods of balancing rotor can be balanced by aligning the. Generally, the rigid rotors can be balanced by the influence coefficient method. The objective was to apply the theory of rotor balancing, gain skills on rotor balancing and get to know how to operate the balancing machine.
Balancing may be performed on the planes of unbalances or any other two convenient planes. Dynamic balancing of rotating machinery experiment technical. This measurement is not needed for balancing the rotor, but will be used later as a check on calculations. As the shaft accelerates toward an unbalance point, the weights. This is important since rotors can generally only be balanced using the rigid rotor method. Us2983148a us528431a us52843155a us2983148a us 2983148 a us2983148 a us 2983148a us 528431 a us528431 a us 528431a us 52843155 a us52843155 a us 52843155a us 2983148 a us2983148 a us 2983148a authority us united states prior art keywords rotor apparatus position rotors housing prior art date 19540817 legal status the legal status is an assumption and is not a legal.
They are the amount and position of the two correction weights required to balance the rotor. Rotor balancing is a fundamental requirement for the smooth operation of turbomachinery. Any rotor with an uneven distribution of mass about its axis of rotation has an unbalance. As a result the dynamic characteristics are totally unlike that encountered with conventional steam turbines. Each correction weight is located in one of the arbitrary chosen radial reference planes on the rotor. These reference planes are usually placed near the support bearings. For static balance, the shaking force must be zero 2. An unbalance is the most common issue affecting the turbomachinery rotors. On completion of this tutorial you should be able to do the following. The diagram below shows masses on two rotors in planes b and c. Install the tracking and balancing equipment as follows.
Devoid of proper balancing, any vehicle be it in air, land or sea, it will affect stability, control and safety. Shop balancing methods the methods employed in shop balancing can have a profound impact on the resulting balance condition of the rotor. The balancing method used depends on rotor design and speed. A rotor can be balanced either by static balancing or by dynamic balancing. The use of an active disk is proposed for actively balancing a rotor by. Dynamic balancing services ihi compressor rotor rokade. This limit is established in general by the capabilities of shop balance machines. Pdf automatic balancing of rotorbearing systems researchgate. Such a rotor does not impart any vibratory force or motion to its bearings as a result of centrifugal forces.
Balancing mc model hb 30 bu belt drive balancing mc model h 40 bu belt drive balancing. Procedure for tracking and dynamic balancing balancing of helicopter rotor blades under centrifugal force field is called dynamic balancing, and is used to correct asymmetries due to mass, aerodynamic and structural behaviors. In heavy industrial machines such as gas turbines and electric generators, vibration can cause catastrophic failure, as well as noise and discomfort. Gardner denver rotor on dynamic balancer while we do offer dynamic rotor balancing if required, first we make every attempt to correct the cause of this vibration rather than compensate for it. Pdf rotating machinery is commonly used in many mechanical systems. Balance quality requirements of rigid rotors ird balancing. Static and dynamic balancing of helicopter tail rotor blade. Improving production through reliable professional services since 1997 we have taken great care in providing our customers with services that improve the availability and reliability of their critical rotating machinery.
Dynamic balancing balance weight distribution 27 figure 16. Rotor balancing methods this section of the paper gives an overview of previously published literature surveys on balancing of rotating machineries. Hardbearing, forceproportional balancing machines have rigid supports and measure force. Balancing is a process of designing or modifying machinery so that the unbalance is reduced to an acceptable level and if possible eliminated entirely. The unique and ideal condition of a rotor when it has neither static nor dynamic unbalance. Feb 02, 2015 dynamic balancing of a turbochargers rotor shaft complete. Dynamic balancing company services that improve the. Elevation view of a rotor having an imbalanced mass. Dynamic balancing at lower guide bearing 22 figure 14.
Check of dynamic balancing at lower guide bearing 26 figure 15. If there is any unbalance present in the parts of rotating. This is so because any rotor cannot be perfectly in a concentric manner mounted within the stator bore of. Way more information than you ever wanted on how to fell a tree. Dynamic balancing the process of balancing is the removal or addition of weight to the unit such that this effective mass center line approaches the true axis. Then multiply e per by rotor weight to obtain the permissible residual unbalance, u per. In 1985, papers were presented at vibration institute meetings on the dynamic analysis and field balancing of 70. To investigate unbalance on a rigid rotor, a laboratory test was done on an unbalanced rigid rotor and both static and dynamic balancing procedures were performed on the rotor. This balancing arbor, when properly balanced, will be identical to the rig shaft and have a maximum dynamic. While we do offer dynamic rotor balancing if required, first we make every attempt to correct the cause of this vibration rather than compensate for it. Rotating machinery rotor balancing lifetime reliability solutions. Dynamic balancing machine specifications and prices, for horizontal balancing machines, by balancemaster, inc. The farther apart these corrective planes are, the smaller, in general, may be the corrective weights. Allocate u per to the balancing correction planes based on rotor configuration.
For instance, dynamic balancing would usually be employed if a rotor is relatively wide, compared to its diameter, so that. Dynamic balancing should not be a substitute for poor machining or other compromise manufacturing practices. A passive dynamic inertial rotor balance system including a plurality of balancing members fitted onto a rotor shaft at locations of predicted maximum shaft modal deflection. A machine operation at high vibration level due to the rotor disk unbalance will result. The effects of those imperfections on the dynamic state of the rotor can be limited by balancing. To learn a simple, practical method of dynamic balancing that can be used in the field and appreciate its. The imbalance measured can then be corrected by adding or subtracting weight from the rotating parts until the vibration is reduced. For dynamic balance, the shaking force and the shaking moment must both be zero. Dynamic balancing of rotating machinery in the field. In the manufacturing process, if proper care is taken to ensure that castings are sound and machining is concentric, then it follows that the two axis will coincide and the assembled rotor will be in a state of balance. Dynamic balancing of a blower impeller for a passenger ship. Dynamic balancing at upper guide bearing 21 figure.
Plan view of an imbalanced rotor at the upper guide bearing. The process of balancing a part without taking it out of the machine is called inplace balancing. The objective was to apply the theory of rotor balancing, gain skills on rotor balancing and. Active balancing and vibration control of rotating machinery many methods for passive balancing have been proposed, such as single plane, two planes or multiplane balancing. Single and multiplane balancing of rotor in static and. In addition to dynamically balancing rotors, pulleys, shafts, and tooling for the spindle motors we manufacture and repair, we offer dynamic balancing services for all types of. With the possible exception of casting voids rarely found in rotors, we find that most properly machined rotors will run within iso ba. In the case of a narrow wheel, balancing simply involves moving the center of gravity to the centre of rotation. Proximity probe on a magnetic mount, above turbine guide.
Rated speed balancing is for high speed rotating components where standard, low speed balancing less than 2000 rpm is not sufficient. These offline balancing methods are very common in industrial applications. Dynamic balancing is a way of balancing machines by rotating parts quickly and measuring the imbalance using electronic equipment. If a rotor is balanced on a low speed balancing machine assuming it is rigid and then in service becomes flexible, then unbalance and thus high vibration, will be the result. Dynamic analysis and field balancing of 100 mw utility gas. The uneven distribution of mass about a rotors rotating centerline. Balancing of rigid rotors general balancing procedures for sizing and positioning corrective masses on rotors are based on the following criteria. Fist volume 22, field balancing large rotating machinery. The following table gives the balancing grade for various types of rotors. Performing step 1 simply requires the user to find the rotor type that most nearly describes the one to be balanced. Dynamic and static balancing in heavy industrial machinery such as generators and motors can cause catastrophic failure, as well as noise and discomfort. A flexible rotor will require multiplane balancing.
Static and dynamic balancing of helicopter tail rotor blade using twoplane balancing method. Us2983148a apparatus for use in the dynamic balancing of. Performing step 1 simply requires the user to find the rotor type that most nearly describes the one. With the possible exception of casting voids rarely found in rotors, we find that most properly machined rotors will run within iso balancing specs. In addition, there is substantial rotorcasing interaction which is not present in conventional steam turbines. Blade balancing rotor blade balancing dynamic rotor track. A rigid rotor can be balanced at the two end planes and will stay in balance when in service. Tool balancing theory rotor unbalances can be caused by design, material, manufacturing and assembly. In dynamic balancing do we need to support the component on the machine in the same location as in assembly. Pdf static and dynamic balancing of rigid rotors prasanna. Each of the balancing members has at least one chamber and located within the at least one chamber is a plurality of movable weights and a viscous fluid. Every rotor has an individual unbalance distribution along its length, even in series production.
To calculate the balancing tolerances, the following formula can be used. Ideally, in the operation of all rotating machinery, the inertia axis of. When balancing such a rotor in a balancing machine, the rotor may be mounted elastically in such a way that it is pivoted to oscillate about some chosen radial axis. The most common forms are combinations of static and dynamic rotor eccentricities. Abstract this paper deals with the dynamic balancing of a blower impeller for the passenger ship. Details of the software products used to create this pdf file can be found in. The balancing of rotating bodies is important to avoid vibration. To help with balancing, it involves simply moving the centre of gravity to the centre of rotation. These two elements of blade balancing must be bought together under a complete but simple blade management plan in order to understand the entire balance problem. Determine the masses to be added on the rotors in planes a and d at radius 40 mm which will produce static and dynamic balance.
These are mainly used in production line balancing such as electric motor rotor manufacture, and the like. Typically, high speed balancing is required when additional vibration modes critical speeds or radial growth of components are encountered at operational speed. Dynamic unbalance a long rotor mounted in bearings at a and b if m 1 m 2 and r 1 r 2 the rotor is statically balanced but dynamically unbalanced. When thinking about blade balancing, we need to think in terms of both static and dynamic balance.
There are four variables to be dealt with when balancing any rigid rotor. Pdf dynamic balancing and shaft alignment researchgate. For a system to be in complete balance both force and couple polygons. Dynamic balancing is the most important concept for rotating parts of marine machinery. Tracking and dynamic balancing tail rotor assembly. Balancing is a procedure in which the mass distribution of a rotor is checked and, if necessary, adjusted. Solid mechanics balancing tutorial balancing of rotating bodies this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 4. After balancing, no bearing reactions remain theoretically. Note 2 the quantitative measure of dynamic unbalance can be given by two complementary unbalance vectors in two specified planes perpendicular to the shaft axis which completely represent the total unbalance of the rotor in a constant rigid state. The method chosen is dependent upon many factors such as physical size, shape, mass, and unbalance limit requirements see iso standard 1940. Basic methods of balancing rotor can be balanced by aligning the rotor mass with the bearing centers norfield, 2006. To help with balancing, it involves simply moving the.
Dynamic balancing is a force balancing and couple balancing operation. Mechanical vibration balance quality requirements for rotors. Tracking and dynamic balancing tail rotor assembly note. Rotating machinery rotor balancing lifetime reliability. Balancing of machinery universitas negeri yogyakarta. Dynamic rotor eccentricity occurs when the rotor axis rotates around a small circle within the stator bore. These two elements of blade balancing must be bought together under a complete but simple blade management plan. Static and dynamic balancing of helicopter tail rotor blade using twoplane balancing method balancing is a rotating component is critical in any mechanism. Yes it is necessary to support the component being balanced at the same or near about of the bearing supports for proper results. Unit 6 introduction to balancing introduction to balancing. The discussion in site and factory methods includes influence. Pdf static and dynamic balancing of helicopter tail rotor.
1225 254 285 1293 766 96 127 917 469 1370 1420 1153 531 300 362 734 594 1230 51 160 74 1082 505 168 1142 589 34 561 910 544 518 802 101 1264 999 141 1171 1173 1043 613 464 955 536 1194