GB2580344A - Method of balancing a rotor - Google Patents
Method of balancing a rotor Download PDFInfo
- Publication number
- GB2580344A GB2580344A GB1900042.1A GB201900042A GB2580344A GB 2580344 A GB2580344 A GB 2580344A GB 201900042 A GB201900042 A GB 201900042A GB 2580344 A GB2580344 A GB 2580344A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rotor
- balancing
- plane
- unbalance
- calibration value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 129
- 230000008569 process Effects 0.000 claims abstract description 53
- 230000000694 effects Effects 0.000 claims abstract description 41
- 238000003860 storage Methods 0.000 claims description 8
- 238000004590 computer program Methods 0.000 claims description 5
- 239000011159 matrix material Substances 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000011437 continuous method Methods 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000005055 memory storage Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M1/00—Testing static or dynamic balance of machines or structures
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
- H02K15/16—Centering rotors within the stator; Balancing rotors
- H02K15/165—Balancing the rotor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M1/00—Testing static or dynamic balance of machines or structures
- G01M1/14—Determining imbalance
- G01M1/16—Determining imbalance by oscillating or rotating the body to be tested
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M1/00—Testing static or dynamic balance of machines or structures
- G01M1/14—Determining imbalance
- G01M1/16—Determining imbalance by oscillating or rotating the body to be tested
- G01M1/24—Performing balancing on elastic shafts, e.g. for crankshafts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M1/00—Testing static or dynamic balance of machines or structures
- G01M1/30—Compensating imbalance
- G01M1/32—Compensating imbalance by adding material to the body to be tested, e.g. by correcting-weights
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Power Engineering (AREA)
- Testing Of Balance (AREA)
Abstract
The unbalance of a first rotor (eg propshaft/driveshaft/Cardan shaft) in at least a first balancing plane is measured in balancing machine 10 and a balancing weight for correcting the unbalance, calculated using a stored calibration value determined from a calibration/balancing process performed on a second rotor, is attached to the first rotor at a calculated angular position of the first balancing plane. The effect of the attached balancing weight is determined by re-measuring the unbalance of the rotor with the determined effect stored as a modified/updated calibration value. If the unbalance of the first rotor is not corrected by the attachment of the balancing weight, a further balancing weight for correcting the unbalance is calculated using the modified/updated calibration value and attached to the first rotor with the unbalance of the first rotor again re-measured. The unbalance of the rotor may be measured and corrected in first and second balancing planes.
Description
Title: Method of balancing a rotor
Description of Invention
The present invention relates to a method of balancing a rotor, such as, for example, a propshaft.
Propshafts, and more generally rotors, can be formed of a single rotor portion or multiple rotor portions linked together in end-to-end alignment. Rotors formed of multiple rotor portions may comprise two or three such portions, and less commonly may comprise four portions.
Balancing is typically carried out on rotors to overcome or lessen the problem of 'unbalance' -the uneven distribution of mass around the axis of rotation of the rotor. Unbalance is when the inertia axis of the rotor is offset from its central axis of rotation, which results from the mass of the rotor not being distributed uniformly about its central axis. Rotors suffering unbalance may generate a moment when rotating which leads to vibration.
It is known to balance a single piece rotor using two balance planes. Each balance plane is a plane disposed substantially perpendicular to the axis of the rotor. When balancing a multiple piece rotor, balancing is carried out in additional balance planes: a two piece rotor may be balanced in three planes, a three piece rotor may be balanced in four planes, and a four piece rotor may be balanced in five planes.
Correction for unbalance is typically carried out by welding or attaching balance weights to the rotor. Rotors are designed with zones where balance weights can be added corresponding to the number of balancing planes, which are usually at or near the end of each rotor portion.
Using known balancing methods and apparatuses, a rotor is loaded in to a balancing machine. Each end of the rotor is located in a respective chuck, to hold that end of the rotor. The chucks are then fitted to spindles, which in turn are mounted to bearings. If the rotor comprises multiple rotor portions, the connection of the two rotor portions are mounted and clamped on centre bearer supports. If a two piece rotor was to be balanced in two separate halves, then one chuck and the centre support would tend to be used rather than mounting that rotor portion in two chucks.
The mechanism for correcting unbalance is automated, by which balance weights are attached, e.g. adhered or welded, to the rotor at a set position along the axis of the rotor for each plane, within specified balance zones. Once weights for all planes (where required) are applied to the rotor, the rotor unbalance is measured again using the same method. If the unbalance measured in any plane remains outside of a predefined tolerance threshold, a second step of correction is typically carried out within the corresponding balance zone.
To take accurate measurements and carry out accurate balancing, flexible rotors must be balanced at or near normal operational speed. The unbalance in flexible rotors is not linear due to the change of shape in the rotor when rotating at speed, and when weights are applied to the rotor. Flexible rotors requiring high accuracy and high volume production are calibrated according to rotor type and in each balancing plane, to compensate for any unbalance crossover effects (often referred to as "cross plane influence") which occur when the amount and angle of unbalance in one plane affects that in another plane. To resolve the crossover effect between planes when balancing a rotor, "specific calibration" or "matrix calibration" is performed.
jh volume production, e.g. where there are a significant number of rotors which are substantially identical / similar, a calibration rotor is first loaded into a balancing machine. The calibration rotor is essentially a master rotor which is already balanced to within a required tolerance, and a first step of the calibration process is to rotate the calibration rotor at the balancing speed and determine any inherent unbalance in the calibration rotor. A temporary calibration weight, which is chosen by an operator, is then added to a first balancing plane of the calibration rotor, and the effect of the calibration weight in that plane (and in the other balancing planes) is measured by measuring unbalance in the calibration rotor, and comparing it to the unbalance in the rotor with no weights attached. That weight is then removed from the first plane and the same or another weight (again chosen by an operator) is added to a second balancing plane and measurements of unbalance in the rotor are taken again. This process is repeated for each balancing plane present (which depends on the type and configuration of rotor). A matrix is then calculated including the "calibration values" which can be used to determine the effect of applying a weight in one plane on the other planes. If measurements are taken in relation to four planes, which would be the case for a three piece rotor, this results in the generation of a four by four matrix of calibration values.
The calibration values are then used for each of the rotors which are then subsequently balanced in that balancing machine (rotors which are substantially identical / similar) to the calibration rotor. Utilising these calibration values means that balancing subsequent rotors is quicker, because any measured unbalance in each rotor can be corrected by selecting appropriate balancing weights, with the knowledge of the crossover effect of adding those weights already known and stored as the calibration values.
In known prior art systems/processes, the calibration process is completely separate from the balancing process. In the balancing process, the rotor to be ned in the balancing machine and rotated at the balancing speed to determine any inherent unbalance in the rotor. Using the stored calibration values from the calibration process, the balancing machine then calculates the balancing weights required at the various balancing planes of the rotor (and their rotational position about the axis of the rotor). The calculated balancing weights are then attached to the rotor at each of the planes (where required). Once this has been carried out, the rotor is again rotated at the balancing speed to determine whether the added balancing weights have balanced the rotor to within the required tolerance. If the rotor is within tolerance, it is removed from the balancing machine and the next rotor is selected. If the rotor is still not balanced within the required tolerance, then the balancing machine, again using the stored calibration values from the calibration process, calculates the balancing weights required at the various balancing planes of the rotor (and their rotational position about the axis of the rotor). These weights (which typically would be smaller than those already added, although they might not be) are then attached to the rotor and the rotor is then rotated again at the balancing speed. This continues until the rotor is balanced to within the required tolerance, although it should be noted that if the master rotor used in the calibration process is balanced to within the required tolerance, only one stage of attaching balancing weights should (ideally) be required to balance each subsequent rotor in that batch.
When balancing, for example, passenger car propshafts (high accuracy, high volume) the above calibration and balancing processes are acceptable because the rotors are the substantially the same and their reaction (varying clearances) is similar. If a different rotor needs to be balanced, the balancing machine is recalibrated (with a different master rotor) or if that configuration/type of rotor has been calibrated before then the calibration values are recalled from a memory storage on or associated with the balancing machine.
rimercial propshaft balancing (e.g. for heavy goods vehicles or the like, which are lower volume and require lower accuracy), the rotors tend to be similar in type (e.g. shape / configuration) but not the same. For example, they may be of similar configuration, but different in length. In the known prior art processes, there are typically two ways of balancing such rotors. In a first known method, a calibration process is performed on each rotor, essentially creating a set of calibration values specific to that rotor. A specific calibration process is therefore carried out, followed by the balancing process, which results in an undesirably long time period for achieving balance of the rotor (within required tolerances).
A first step of the calibration process for such a rotor is to rotate the rotor to be balanced at the balancing speed and determine any inherent unbalance in the rotor to be balanced. A temporary calibration weight, which is chosen by an operator, is then added to a first balancing plane of the rotor to be balanced, and the effect of the calibration weight in that plane (and in the other balancing planes) is measured by measuring unbalance in the rotor to be balanced, and comparing it to the unbalance in the rotor with no weights attached. That weight is then removed from the first plane and the same or another weight (again chosen by an operator) is added to a second balancing plane and measurements of unbalance in the rotor are taken again. This process is repeated for each balancing plane present (which depends on the type and configuration of rotor). A matrix is then calculated including the "calibration values" which can be used to determine the effect of applying a weight in one plane on the other planes. If measurements are taken in relation to four planes, which would be the case for a three piece rotor, this results in the generation of a four by four matrix of calibration values.
The calibration values are then used for the balancing process which follows.
In the balancing process, the rotor to be balanced remains in the balancing machine and is rotated at the balancing speed to determine any inherent tor. Using the stored calibration values specific to that rotor (which have just been measured/calculated), the balancing machine then calculates the balancing weights required at the various balancing planes of the rotor (and their rotational position about the axis of the rotor). The calculated balancing weights are then attached to the rotor at each of the planes (where required). Once this has been carried out, the rotor is again rotated at the balancing speed to determine whether the added balancing weight(s) have balanced the rotor to within the required tolerance. If the rotor is within tolerance, it is removed from the balancing machine. If the rotor is still not balanced within the required tolerance, then the balancing machine, again using the stored calibration values specific to that rotor, calculates the balancing weights required at the various balancing planes of the rotor (and their rotational position about the axis of the rotor). These weights (which typically would be smaller than those already added, although they might not be) are then attached to rotor and the rotor is then rotated again at the balancing speed. This continues until the rotor is balanced to within the required tolerance. The next rotor is then placed in the machine and a specific calibration process and then balancing process are performed for that rotor.
Alternatively, if the calibration process is not carried out on each rotor, calibration values are used from another similar (but not identical) rotor. This means, essentially, that the operator has no idea how realistic those stored calibration values are for the rotor to be balanced. In such a process, the rotor to be balanced is placed in the balancing machine and rotated at the balancing speed to determine any inherent unbalance in the rotor. Using the stored calibration values which are not specific to that rotor, the balancing machine then calculates the balancing weights required at the various balancing planes of the rotor (and their rotational position about the axis of the rotor). Of course, these calculations are really estimates, based on the non-specific calibration values being used. The calculated balancing weights are then attached to the rotor at each of the planes (where required). Once this has been carried out, rotated at the balancing speed to determine whether the added balancing weights have balance the rotor to within the required tolerance. If the rotor is within tolerance (which is highly unlikely), it is removed from the balancing machine. If the rotor is still not balanced within the required tolerance (most likely scenario), then the balancing machine, again using the stored calibration values not specific to that rotor, calculates what additional balancing weights are required at the various balancing planes of the rotor (and their rotational position about the axis of the rotor). These additional weights (which hopefully would be smaller than those already added, although they might not be) are then attached to rotor and the rotor is then rotated again at the balancing speed. This continues until the rotor is balanced to within the required tolerance. Whilst this methodology removes the need to calibrate the balancing machine for each rotor, it inevitably results in a much longer balancing process, with the rotor having to be rotated at the balancing speed many times. This is because the in-plane and cross-plane influence of the balancing weights is not known for the specific rotor. In other words, the balancing machine cannot accurately predict the impact of a certain balancing weight added to one plane on that plane or other balancing planes (if they exist for the rotor being balanced).
It is an object of the present invention to address this problem.
According to a first aspect of the invention we provide a method of balancing a first rotor, the method including the steps of: mounting the first rotor in a balancing machine capable of rotating the first rotor about its axis; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor in at least a first balancing plane; using a stored calibration value(s) from a calibration or balancing process or method performed on a different rotor from the first rotor, to ig weight required to be attached in the first balancing plane, which would balance the first rotor in that plane if the calibration value(s) were correct for the first rotor; attaching the calculated balancing weight to the first rotor at the first balancing plane and in a calculated angular position about the axis of the first rotor; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor at least at the first balancing plane and also determining the effect of the attached balancing weight on the unbalance of the first rotor; storing said effect as a modified or updated calibration value(s); using the modified or updated stored calibration value(s) to calculate a further balancing weight (if required) to be attached in the first balancing plane; and if required, attaching the further balancing weight to the first rotor at the first balancing plane and in a calculated angular position about the axis of the first rotor, causing the first rotor to rotate about its axis, and measuring the unbalance in the first rotor at least at a first balancing plane.
According to a second aspect of the invention we provide a method of balancing a first rotor, the method including the steps of: mounting the first rotor in a balancing machine capable of rotating the first rotor about its axis, wherein the first rotor has first and second balancing planes; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor at the first and second balancing planes, before any balancing weight(s) has been attached to the first rotor; using a stored calibration value(s) from a calibration or balancing process or method performed on a rotor different from the first rotor, to calculate a balancing weight(s) required to be attached in the first balancing balance the first rotor in the first balancing plane if the calibration value(s) were correct for the first rotor; attaching the calculated balancing weight(s) to the first rotor at the first balancing plane and in a calculated angular position about the axis of the first rotor; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor at the first and second balancing planes and determining the effect of the balancing weight attached at the first balancing plane on the unbalance of the first rotor; storing said effect as a modified or updated calibration value(s) or an alternative calibration value(s); using the modified or updated stored calibration value(s) and/or the alternative calibration value(s) or the calibration value(s) from the calibration or balancing process or method performed on the rotor different from the first rotor to calculate a further balancing weight (if required) to be attached in the second balancing plane; and if required, attaching the further balancing weight to the first rotor at the second balancing plane and in a calculated angular position about the axis of the first rotor, causing the first rotor to rotate about its axis, and measuring the unbalance in the first rotor at the first and second balancing planes.
According to a third aspect of the invention we provide a balancing machine including a control system for controlling the balancing machine so as to perform the method of the first and/or second aspects of the invention.
According to a fourth aspect of the invention we provide a system including a balancing machine, a control system and a storage facility, wherein the control system and storage facility are remote from but connected to the balancing machine, such that the balancing machine may be controlled thereby and wherein the control system is capable of controlling the balancing machine so as to perform the method of the first and/or second aspects of the invention.
According to a fifth aspect of the invention we provide a computer program including instructions to cause a balancing machine to execute the steps of the method of the first and/or second aspects of the invention.
Further features of the various aspects of the invention are described in the appended claims.
Embodiments of the invention will now be described, by way of example only, with reference to the following figures, of which: Figure 1 is a diagrammatic view of rotor having a single rotor portion mounted in a rotor balancing machine of embodiments of the invention; Figure 2 is a diagrammatic view of rotor having two rotor portions connected to each other which is mounted in a rotor balancing machine of embodiments of the invention; Figure 3 is a diagrammatic view of rotor having three rotor portions connected 20 to each other which is mounted in a rotor balancing machine of embodiments of the invention; Figure 4 is a diagrammatic view of the rotor of figure 1showing its balancing planes A and B; Figure 5 is a diagrammatic view of the rotor of figure 2 showing its balancing planes A and B; Figure 6 is a diagrammatic view of the rotor of figure 3 showing its balancing 30 planes A and B; hart illustrating a prior art calibration process for a rotor and balancing machine; Figure 8 is a flow chart illustrating a prior art balancing process for a rotor and balancing machine; and Figures 9 and 10 are flow charts illustrating a combined calibration and balancing process/method according to the present invention.
With reference to the drawings, Figure 1 shows some, but not all, component parts of a rotor balancing machine 10 onto which a rotor 12, having only a single rotor portion, is mounted. The rotor 12 may be of any suitable type, as is commonly known in the field, such as propshafts including driveshafts and Cardan shafts, for example. The rotor balancing machine 10 comprises a machine having first and second chucks 14, 16 for mounting the rotor 12 by supporting either end of the rotor 12. Each chuck 14, 16 is fitted to a spindle. The balancing machine is operable to rotate the rotor 12 about its axis to a specified speed of rotation.
If the rotor comprises multiple rotor portions, the connection of the two adjacent rotor portions are mounted and clamped on centre bearer supports. Such examples of rotors 210, 310 are shown in figures 2 and 3 with bearer supports 218, 318. In the two rotor portion example, each rotor portion is referenced as part 212. In the three rotor portion example, each rotor portion is referenced as part 312. Parts which correspond to the example shown in figure 1 have been given the same reference numeral but with the addition of 100 (for figure 2) and 200 (for figure 3).
The machine 10 includes (one or more) measuring devices operable to 30 measure unbalance in the rotor 12. The measuring devices are of a standard type generally known in the art, for measuring unbalance in a rotor. Typically, i to a predefined speed and the unbalance is measured by a computer based electronic measuring system. The measuring system receives a signal from a pickup transducer mounted to each bearer support and chuck -the number of pickup transducers corresponding to the number of balancing planes. Once per revolution of the rotor, a signal from an encoder is used to determine the angle of unbalance. The unbalance amount and angle may be displayed on a display screen and/or stored in a suitable storage device.
The machine also includes a balancing system that is operable to attach balance weights to a surface of the rotor 12. In embodiments, the attachment of balance weights to the surface of the rotor 12 is automated. In other embodiments, the attachment of weights is carried out manually (e.g. by hand placement). The balancing system employs standard known equipment for attaching balancing weights to a rotor, e.g. by welding or adhering.
With reference to Figures 1 and 4, a rotor balancing machine 10 of the prior art is shown, having a pair of chucks 14, 16 for mounting the rotor 12, as previously described. First and second axial balancing planes A, B are located towards either end of the rotor 12. By axial plane, we mean a plane lying transverse to the axis of the rotor.
The method of balancing using the apparatus of the prior art involves rotating the rotor about its axis, and then measuring any unbalance in the rotor. Before balancing can be performed the balancing machine must be calibrated for the rotor type / configuration / size. This is achieved as discussed above and as shown in the flow chart of figure 7. Essentially balancing weights which are selected by an operator are attached to planes A and B at different times and in each case the rotor is rotated at the balancing speed. The effect of those added weights is stored as calibration values, so that the balancing machine effect on unbalance of the rotor at each plane A, B and the cross-plane effect.
Once such a calibration has been performed the rotor (or rotors, if there is a batch of identical / substantially similar rotors) is balanced using the prior art method shown in the flow chart of figure 8. There, the balancing machine uses the stored calibration values from the calibration process to calculate the weights required to be added to planes A and B to balance the rotor (to within the required tolerance). The weights are then attached at those positions, and the rotor rotated to check for unbalance. More weights are added if necessary, or the rotor removed and the next one of the batch mounted in the balancing machine.
As detailed above, when commercial propshafts are to be balanced (e.g. for heavy goods vehicles or the like, which are lower volume and require lower accuracy), the rotors tend to be similar in type (e.g. shape / configuration) but not the same. The known prior art processes result in either multiple balancing stages having to be performed, or specific calibration for each rotor, both of which are inefficient time-wise.
The present invention utilises a method which is advantageous over the prior art processes/methods. Figures 9 and 10 illustrate a flow chart showing the method or process steps of the invention for a single rotor having two balancing planes. Before discussing that flow chart, it should be noted that the inventive method can be utilised on rotors which only have a single balancing plane or indeed on rotors having multiple balancing planes (e.g. those shown in figures 2, 3, 5 and 6). The following description should therefore not be considered to be a detailed description of the invention, but rather an example of the invention with reference to a two plane rotor being balanced.
ancing a (first) two plane rotor 12 includes the first step of mounting the first rotor in the balancing machine 10 which capable of rotating the first rotor 12 about its axis. The following method steps are then performed.
The first rotor 12 is rotated about its axis and the machine 10 measures the unbalance in the first rotor 12 at the balancing planes A and B, before any balancing weights has been attached to the first rotor 12. Using stored calibration values from a calibration or balancing process or method performed on a rotor different from the first rotor 12 (e.g. a rotor previously balanced on the same or a different balancing machine), the machine 10 calculates a balancing weight required to be attached in the balancing plane A, which would balance the first rotor 12 in the balancing plane A if the calibration values were correct for the first rotor 12. The calculated balancing weight is then attached to rotor 12 at the balancing plane A and in a calculated angular position about the axis of the first rotor 12.
The first rotor 12 is rotated about its axis and the machine 10 measures the unbalance in the rotor 12 at the balancing planes A and B and determines the effect of the attached balancing weight on the unbalance of the rotor.
Essentially, the machine looks to see whether and to what extent the unbalance has been changed at both planes A and B as a result of the weight attached at plane A. The machine then stores the measured effect as modified or updated calibration values, e.g. modifying or overwriting the calibration values which were recalled from the calibration or balancing process or method performed on a rotor different from the rotor 12. Alternatively, or in addition, the machine stores the measured effect as an alternative calibration value(s), e.g. storing a calibration value(s) in parallel with the existing calibration value(s) from the cing process or method performed on a rotor different from the first rotor 12.
Using the modified or updated stored calibration value(s), and/or the alternative calibration value(s), or the calibration value(s) from the calibration or balancing process or method performed on the rotor different from the first rotor, the machine 10 calculates whether a further balancing weight is required to be attached in the balancing plane B and if so, what weight is required. The calculated weight is then attached to the rotor 12 at the balancing plane B and in a calculated angular position about the axis of the rotor 12. The rotor 12 is then again rotated about its axis and the machine 10 measures the unbalance in the rotor 12. If the rotor 12 is balanced to within the required tolerance (which in some circumstances may be the case, especially if larger tolerances are permitted, especially if the previous rotor was similar to the first rotor 12), then the rotor 12 is removed from the machine and the next (hereinafter referred to as "second") rotor mounted in its place.
If the rotor 12 is not balanced to within the required tolerance, then whilst the rotor 12 is being rotated about its axis the machine 10 also determines the effect of the balancing weight attached at the balancing plane B on the unbalance of the rotor 12 in the balancing planes A and B. The machine then stores the measured effect as modified or updated calibration values, e.g. modifying or overwriting the calibration values which were recalled from the calibration or balancing process or method performed on a rotor different from the rotor 12. Again, alternatively, or in addition, the machine stores the measured effect as an alternative calibration value(s), e.g. storing a calibration value(s) in parallel with the existing calibration value(s) from the calibration or balancing process or method performed on a rotor different from the first rotor 12.
ier modified or updated stored calibration values and/or the alternative calibration value(s) the machine 10 calculates whether a yet further balancing weight is required to be attached in the balancing plane A and/or balancing plane B and if so, what weight(s) is required. The calculated weight(s) is then attached to the rotor 12 at the balancing plane A and/or B and in a calculated angular position(s) about the axis of the rotor 12. The rotor 12 is then again rotated about its axis and the machine 10 measures the unbalance in the rotor 12. If the rotor 12 is balanced to within the required tolerance, then the rotor 12 is removed from the machine 10 and the second rotor mounted in its place. If the rotor 12 is still not balanced to within the required tolerance, then the machine 10 measures the unbalance in the rotor 12, with the above being repeated (updating calibration values, or storing alternative calibration values, and calculating weights to be added).
Once the second rotor is mounted in the machine, the inventive method continues as it did for the first rotor 12. In other words, the second rotor is rotated about its axis and the machine 10 measures the unbalance in the second rotor at the balancing planes A and B thereof, before any balancing weights have been attached to the second rotor. Using the stored calibration values (either the modified or updated calibration value(s) or the alternative calibration value(s)) from the combined calibration and balancing method performed on the first rotor 12, the machine 10 calculates a balancing weight required to be attached in the balancing plane A of the second rotor, which would balance the second rotor in its balancing plane A if the calibration values were correct for the second rotor (if, for example, the second rotor was identical or substantially identical to the first rotor 12). The calculated balancing weight is then attached to second rotor at its balancing plane A and in a calculated angular position about the axis of the second rotor.
The second rotor is rotated about its axis and the machine 10 measures the unbalance in the rotor 12 at the balancing planes A and B and determines the ed balancing weight on the unbalance of the second rotor. Essentially, the machine looks to see whether and to what extent the unbalance has been changed at both planes A and B as a result of the weight attached at plane A of the second rotor.
The machine then stores the measured effect as modified or updated calibration values, e.g. modifying or overwriting the calibration values which were recalled from the calibration or balancing process or method performed on the first rotor 12. Alternatively, or in addition, the machine stores the measured effect as an alternative calibration value(s), e.g. storing a calibration value(s) in parallel with the existing calibration value(s) from the calibration or balancing process or method performed on the first rotor 12.
Using the modified or updated stored calibration value(s), and/or the alternative calibration value(s), or the calibration value(s) from the calibration or balancing process or method performed on the first rotor the machine 10 calculates whether a further balancing weight is required to be attached in the balancing plane B of the second rotor and if so, what weight is required. The calculated weight is then attached to the rotor 12 at the balancing plane B and in a calculated angular position about the axis of the second rotor. The second rotor 12 is then again rotated about its axis and the machine 10 measures the unbalance in the second rotor. If the second rotor is balanced to within the required tolerance (which in some circumstances may be the case, especially if larger tolerances are permitted), then second rotor is removed from the machine and the third rotor mounted in its place.
If the second rotor is not balanced to within the required tolerance, then whilst the second rotor is being rotated about its axis the machine 10 also determines the effect of the balancing weight attached at the balancing plane B on the unbalance of the second rotor in the balancing planes A and B. The machine then stores the measured effect as modified or updated calibration ing or overwriting the calibration values which were recalled from the calibration or balancing process or method performed on a rotor different from the second rotor. Again, alternatively, or in addition, the machine stores the measured effect as an alternative calibration value(s), e.g. storing a calibration value(s) in parallel with the existing calibration value(s) from the calibration or balancing process or method performed on the first rotor 12.
Using the now further modified or updated stored calibration values and/or the alternative calibration value(s) the machine 10 calculates whether a yet further balancing weight is required to be attached in the balancing plane A and/or balancing plane B of the second rotor and if so, what weight(s) is required. The calculated weight(s) is then attached to the second rotor at the balancing plane A and/or B and in a calculated angular position(s) about the axis of the second rotor. The second rotor is then again rotated about its axis and the machine 10 measures the unbalance in the second rotor. If the second rotor is balanced to within the required tolerance, then the second rotor is removed from the machine and a third rotor mounted in its place. If the second rotor is still not balanced to within the required tolerance, then whilst the second rotor is being rotated about its axis the machine 10 measures the unbalance in the second rotor, with the above method steps being repeated (updating calibration values, or storing alternative calibration values, and calculating weights to be added).
If the method of the invention is to be used for balancing rotors with three or more balancing planes, then the above described method is utilised, but with the modification that unbalance is measured in all three (or more) balancing planes. When a balancing weight is attached to the rotor at one of the planes, the effect of that weight on the unbalance of the rotor is measured at all balancing planes and the stored calibration values are modified / updated as a result, or alternative calibration value(s) are stored.
If the method of the invention is to be used for balancing a rotor with only a single balancing plane, the above method is performed, but the effect of a balancing weight added to the single balancing plane is only measured at that plane. In such a scenario, the calibration value(s) is modified and the rotor re-rotated. It may be necessary, in such a situation, to add a further weight at the single balancing plane. After a first balancing weight has been attached to the rotor, the modified/updated calibration value(s) stored will be specific to that rotor, meaning that balancing to within the required tolerance will be possible at the next balancing stage.
Advantageously, the method of the present invention combines a calibration and balancing process or method into a single continuous process / method, which results in efficiency savings over known processes. In the method of the invention, even if the previously stored calibration value(s) are significantly out with respect to the rotor currently being balanced (which may be the case), the step of adding a calculated balancing weight to one balancing plane (e.g. the second step of the present invention as described), still results in a reduction of the inherent unbalance of the rotor, meaning that subsequent steps (adding further weights) are more likely to result in the rotor being balanced to within acceptable tolerances. Essentially, the rotor is balanced and the machine calibrated for that specific rotor at the same time as unbalance is reduced.
The balancing machine described above may include a control system capable of performing the required steps of the methods and, preferably, a storage facility or device for storing the calibration value(s). Alternatively, the control system and storage facility may be remote from but connected to the balancing machine, such that the balancing machine may be controlled thereby. The control system may include or be connected to a computer program including instructions to cause the balancing machine to execute the )d. A computer-readable medium, e.g. of removable form, may therefore be provided having stored thereon a computer program including instructions to cause the balancing machine to execute the steps of the method.
When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and/or to encompass equivalents.
Claims (14)
- CLAIMS1. A method of balancing a first rotor, the method including the steps of: mounting the first rotor in a balancing machine capable of rotating the first rotor about its axis; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor in at least a first balancing plane; using a stored calibration value(s) from a calibration or balancing process or method performed on a different rotor from the first rotor, to calculate a balancing weight required to be attached in the first balancing plane, which would balance the first rotor in that plane if the calibration value(s) were correct for the first rotor; attaching the calculated balancing weight to the first rotor at the first balancing plane and in a calculated angular position about the axis of the first rotor; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor at least at the first balancing plane and also determining the effect of the attached balancing weight on the unbalance of the first rotor; storing said effect as a modified or updated calibration value(s); using the modified or updated stored calibration value(s) to calculate a further balancing weight (if required) to be attached in the first balancing plane; and if required, attaching the further balancing weight to the first rotor at the first balancing plane and in a calculated angular position about the axis of the first rotor, causing the first rotor to rotate about its axis, and measuring the unbalance in the first rotor at least at a first balancing plane.
- 2. A method according to claim 1 wherein if a further balancing weight is not required to be attached to the first rotor at the first balancing plane, the method includes the step of removing the first rotor from the balancing machine.
- 3. A method according to claim 2 wherein the method includes the steps of: mounting a second rotor in the balancing machine; measuring the unbalance in the second rotor at least at a first balancing plane; using the modified or updated stored calibration value(s) from the calibration or balancing process or method performed on the first rotor, to calculate a balancing weight required to be attached in the first balancing plane, which would balance the second rotor in that plane if the calibration value(s) were correct for the second rotor; attaching the calculated balancing weight to the second rotor at the first balancing plane and in a calculated angular position about the axis of the second rotor; causing the second rotor to rotate about its axis; measuring the unbalance in the second rotor at least at the first balancing plane and also determining the effect of the attached balancing 20 weight on the unbalance of the second rotor; storing said effect as a modified or updated calibration value(s); using the modified or updated stored calibration value(s) to calculate a further balancing weight (if required) to be attached in the first balancing plane; and if required, attaching the further balancing weight to the second rotor at the first balancing plane and in a calculated angular position about the axis of the second rotor, causing the second rotor to rotate about its axis, and measuring the unbalance in the second rotor at least at a first balancing plane.
- 4. A method of balancing a first rotor, the method including the steps of: mounting the first rotor in a balancing machine capable of rotating the first rotor about its axis, wherein the first rotor has first and second balancing planes; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor at the first and second balancing planes, before any balancing weight(s) has been attached to the first rotor; using a stored calibration value(s) from a calibration or balancing process or method performed on a rotor different from the first rotor, to calculate a balancing weight(s) required to be attached in the first balancing plane, which would balance the first rotor in the first balancing plane if the calibration value(s) were correct for the first rotor; attaching the calculated balancing weight(s) to the first rotor at the first balancing plane and in a calculated angular position about the axis of the first rotor; causing the first rotor to rotate about its axis; measuring the unbalance in the first rotor at the first and second balancing planes and determining the effect of the balancing weight attached at the first balancing plane on the unbalance of the first rotor; storing said effect as a modified or updated calibration value(s) or an alternative calibration value(s); using the modified or updated stored calibration value(s) and/or the alternative calibration value(s) or the calibration value(s) from the calibration or balancing process or method performed on the rotor different from the first rotor to calculate a further balancing weight (if required) to be attached in the second balancing plane; and if required, attaching the further balancing weight to the first rotor at the second balancing plane and in a calculated angular position about the axis of the first rotor, causing the first rotor to rotate about its axis, and measuring the unbalance in the first rotor at the first and second balancing planes.
- 5. A method according to claim 4 wherein the method further includes: measuring the unbalance in the first rotor at the first and second balancing planes and determining the effect of the balancing weight attached at the second balancing plane on the unbalance of the first rotor in the first and 5 second planes; storing said effect as a modified or updated calibration value(s) or an alternative calibration value(s); using the modified or updated stored calibration value(s) and/or the alternative calibration value(s) to calculate a further balancing weight (if required) to be attached in the first and/or second balancing plane(s); if required, attaching the further balancing weight to the first rotor at the first and/or second balancing plane(s) and in a calculated angular position(s) about the axis of the first rotor, causing the first rotor to rotate about its axis, and measuring the unbalance in the first rotor at the first and second balancing 15 planes.
- 6. A method according to claim 4 or claim 5 wherein if a further balancing weight(s) is not required to be attached to the first rotor at the first and/or second balancing planes, the method includes the step of removing the first rotor from the balancing machine.
- 7. A method according to claim 4, 5 or 6 wherein the method includes the steps of: mounting a second rotor in a balancing machine capable of rotating the second rotor about its axis, wherein the second rotor has first and second balancing planes; causing the second rotor to rotate about its axis; measuring the unbalance in the second rotor at the first and second balancing planes, before any balancing weight(s) has been attached to the second rotor; using the modified or updated stored calibration value(s) or the alternative calibration value(s) from the calibration or balancing process or method performed on the first rotor, to calculate a balancing weight required to be attached in the first balancing plane, which would balance the second rotor in that plane if the calibration value(s) were correct for the second rotor; attaching the calculated balancing weight to the second rotor at the first balancing plane and in a calculated angular position about the axis of the second rotor; causing the second rotor to rotate about its axis; measuring the unbalance in the second rotor at the first and second balancing planes and also determining the effect of the balancing weight attached at the first balancing plane on the unbalance of the second rotor; storing said effect as a modified or updated calibration value(s) or an alternative calibration value(s); using the modified or updated stored calibration value(s) and/or the alternative calibration value(s) or the calibration value(s) from the calibration or balancing process or method performed on the first rotor to calculate a further balancing weight (if required) to be attached in the second balancing plane; and if required, attaching the further balancing weight to the second rotor at the second balancing plane and in a calculated angular position about the axis of the second rotor, causing the second rotor to rotate about its axis, and measuring the unbalance in the second rotor at the first and second balancing planes.
- 8. According to claim 7 wherein the method further includes: measuring the unbalance in the second rotor at the first and second balancing planes and determining the effect of the balancing weight attached at the second balancing plane on the unbalance of the second rotor in the first 30 and second planes; storing said effect as a modified or updated calibration value(s) or an alternative calibration value(s); using the modified or updated stored calibration value(s) and/or the alternative calibration value(s) to calculate a further balancing weight(s) (if required) to be attached in the first and/or second balancing planes; if required, attaching the further balancing weight(s) to the second rotor at the first and/or second balancing plane and in a calculated angular position about the axis of the second rotor, causing the second rotor to rotate about its axis, and measuring the unbalance in the second rotor at the first and second balancing planes.
- 9. A method according to claims 4 or 5 wherein, if the rotor to be balanced includes third, fourth or more balancing planes, the method includes the steps of performing for the third, further or more balancing planes, the steps as performed for the first and second balancing planes.
- 10. A balancing machine including a control system for controlling the balancing machine so as to perform the method as set out in any one of the preceding claims.
- 11. A balancing machine according to claim 10 including a storage facility for storing a calibration value(s) relating to a rotor.
- 12. A system including a balancing machine, a control system and a storage facility, wherein the control system and storage facility are remote from but connected to the balancing machine, such that the balancing machine may be controlled thereby and wherein the control system is capable of controlling the balancing machine so as to perform the method as set out in any one of the claims 1 to 9.
- 13. A computer program including instructions to cause a balancing machine to execute the steps of the method of any one of claims 1 to 9.
- 14. A computer-readable medium having stored thereon the computer program of claim 13.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1900042.1A GB2580344B (en) | 2019-01-02 | 2019-01-02 | Method of balancing a rotor |
| PCT/GB2019/053661 WO2020141315A1 (en) | 2019-01-02 | 2019-12-20 | Method of balancing a rotor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1900042.1A GB2580344B (en) | 2019-01-02 | 2019-01-02 | Method of balancing a rotor |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201900042D0 GB201900042D0 (en) | 2019-02-13 |
| GB2580344A true GB2580344A (en) | 2020-07-22 |
| GB2580344B GB2580344B (en) | 2023-06-14 |
Family
ID=65364729
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1900042.1A Active GB2580344B (en) | 2019-01-02 | 2019-01-02 | Method of balancing a rotor |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2580344B (en) |
| WO (1) | WO2020141315A1 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4926341A (en) * | 1986-12-24 | 1990-05-15 | Carl Schenck Ag | Method and apparatus for calibration of balancing unit |
| WO1995034871A1 (en) * | 1994-06-14 | 1995-12-21 | Scientific-Atlanta, Inc. | Method and apparatus for automatically balancing rotating machinery |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0720359B2 (en) * | 1990-03-16 | 1995-03-06 | 株式会社荏原製作所 | Unbalance correction device for rotating body |
| FR2713771B1 (en) * | 1993-12-08 | 1996-03-01 | Electricite De France | Method, device and application for dynamic balancing of a rotating rotating part. |
| DE19859664A1 (en) * | 1998-12-23 | 2000-06-29 | Schenck Vibro Gmbh | Method and device for balancing a rotor |
| EP3179611B1 (en) * | 2015-12-10 | 2018-06-27 | Skf Magnetic Mechatronics | Balancing method for balancing at high speed a rotor of a rotary machine |
-
2019
- 2019-01-02 GB GB1900042.1A patent/GB2580344B/en active Active
- 2019-12-20 WO PCT/GB2019/053661 patent/WO2020141315A1/en active Application Filing
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4926341A (en) * | 1986-12-24 | 1990-05-15 | Carl Schenck Ag | Method and apparatus for calibration of balancing unit |
| WO1995034871A1 (en) * | 1994-06-14 | 1995-12-21 | Scientific-Atlanta, Inc. | Method and apparatus for automatically balancing rotating machinery |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201900042D0 (en) | 2019-02-13 |
| WO2020141315A1 (en) | 2020-07-09 |
| GB2580344B (en) | 2023-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7328614B2 (en) | Vehicle wheel balancer system | |
| US10101235B2 (en) | Method to determine the unbalance of a rotor | |
| EP1300665B1 (en) | Vehicle wheel balancer and wheel lateral force measurement | |
| US7320248B2 (en) | Method and apparatus for determining imbalance correction weights for a rotating body | |
| US5365786A (en) | Wheel balancing apparatus and method | |
| JPH0665976B2 (en) | Apparatus and method for calibrating a wheel balancer on two sides | |
| CN101223430A (en) | Method for determining an imbalance condition of a rotating body | |
| JP2001510573A (en) | How to balance a rotating body | |
| US4926341A (en) | Method and apparatus for calibration of balancing unit | |
| US20200041373A1 (en) | Method and machine for balancing a vehicle wheel | |
| JP7382143B2 (en) | How to calibrate a balancing machine | |
| US20100186502A1 (en) | Method and wheel balancer for balancing a vehicle wheel | |
| GB2580344A (en) | Method of balancing a rotor | |
| US11060941B2 (en) | Method for determining an unbalance of a shaft-elastic rotor with reference to the outward deflection | |
| JP2004132975A (en) | Balance testing machine for rotary body, especially wheel of automobile | |
| GB2515062A (en) | Method and apparatus for balancing a rotor | |
| JPH0222327B2 (en) | ||
| JP2007510135A5 (en) | ||
| US7610808B2 (en) | Method for balancing motor vehicle wheels | |
| KR100869193B1 (en) | Method And Arrangement For Calibrating An Unbalance Measuring Apparatus | |
| US8863573B2 (en) | Multiple speed dynamic shaft balancing | |
| US20170227414A1 (en) | Method and machine for balancing a vehicle wheel | |
| CN110207894B (en) | Calibration method of tire balance system | |
| CN112710428B (en) | Dynamic balance correction method and device based on material increase | |
| JP4585922B2 (en) | Weighing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) |
Free format text: REGISTERED BETWEEN 20200723 AND 20200729 |