航空 发表于 2011-4-11 09:38:45

CFM56-7B TRAINING MANUAL ENGINE FAN TRIM BALANCE (3 SHOT PLOT)

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航空 发表于 2011-4-11 09:39:02

Page 1<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>ENGINE FAN TRIM BALANCE (3 SHOT PLOT)<BR>Objectives:<BR>Given an Objective Exercise, the student will:<BR>- identify the conditions where fan trim balance must be performed on the CFM56-7engine. (1.A.a.)<BR>- state the purpose of the engine fan trim balance. (2.B.a.)<BR>- identify the methods used for balancing the engine. (1.B.a.)<BR>- Perform the maintenance practice calculations for the 3 shot plot procedure. (3.E.a.)<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 2<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>FAN TRIM BALANCE<BR>Introduction<BR>Why is fan trim balance necessary for the CFM56-7B<BR>engine?<BR>Purpose (2.B.a.)<BR>The purpose of the engine fan trim balance is to bring<BR>back the engine vibration level to a satisfactory level.<BR>This ensures that:<BR>- The engine reliability will not be affected by<BR>abnormal vibration,<BR>- Engine performance level is maintained for all<BR>operational phases,<BR>- Cabin noise is maintained to a satisfactory level.<BR>The trim balance procedure should limit vibration levels<BR>measured on fan and Low Pressure Turbine to 1.5 AVM<BR>units during all engine ground runs.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 3<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>FAN TRIM BALANCE<BR>Page 4<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>FAN TRIM BALANCE<BR>Identification (1.A.a)<BR>These are the conditions where Fan Trim balance<BR>procedure is performed on the CFM56-7B to reduce<BR>engine vibration levels:<BR>- Fan or/and LPT vibrations are equal or more<BR>than 3 AVM units or 6 mils Double Amplitude.<BR>- After the replacement of 1or more fan blades<BR>and the correction weight installed on the spinner<BR>cone is more than 3.36 pound inches or 600 cm.g.<BR>- After the repair of 1or more fan blades<BR>and the correction weight installed on the spinner<BR>cone is more than 3.36 pound inches or 600 cm.g.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 5<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>REASONS TO PERFORM A FAN TRIM BALANCE<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 6<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>FAN TRIM BALANCE<BR>Maintenance Practice (3.E.a)<BR>These are the two different maintenance practice<BR>procedures available to perform fan trim balance:<BR>- Airborne Vibration Monitoring Unit (AVM) Method<BR>-The 3 Shot Plot Method<BR>Airborne Vibration Monitoring Unit (AVM)<BR>The procedure using the Boeing on board optional<BR>equipment installed in the airplane electronic bay on the<BR>E3-2 shelf. This procedure is uses the vibration data for<BR>phase angle and vibration levels collected during the last<BR>32 flight legs and when necessary during engine ground<BR>runs.<BR>The AVM uses these signal inputs to calculate vibration<BR>levels:<BR>-Vibration sensor from N1 bearing<BR>-Vibration sensor from the FFCCV<BR>-N1 Speed Sensor<BR>-N2 Speed Sensor<BR>The AVM signal conditioner continuously calculates<BR>vibration data for several areas of each engine.<BR>-Fan and LP compressor<BR>-HPC Compressor<BR>-HPT Turbine<BR>-LPT turbine<BR>The highest vibration level is displayed on the CDS, on<BR>the vibration indicator.<BR>The four possible vibration monitoring units are the<BR>(Endevco -203, -213 and Vibrometer -103, -113). These<BR>units calculate the amount and location of weight<BR>necessary to balance the engine back to a normal level.<BR>The PO weight is selected and then needs to be installed<BR>in the engine rear cone by the technician.<BR>(Refer to the AMM 71-00-00 for more information.)<BR>The 3 Shot Plot Method<BR>In case your aircraft is not equipped with such optional<BR>vibration monitoring units, you still have one way to get<BR>your engine balanced using the alternate manual<BR>procedure called "the 3 shot plot."<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 7<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 8<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>FAN TRIM BALANCE<BR>General (3.E.a)<BR>The 3 shot plot procedure philosophy<BR>This method is used when no equipment is available to<BR>find out the phase angle of the engine unbalance.<BR>To find out the location and amount of weight to install on<BR>the engine rear spinner cone, engine runs must be<BR>performed.<BR>A minimum of 5 runs are necessary.<BR>Initial run<BR>The actual engine unbalanced condition is recorded<BR>through different engine speeds.<BR>First run<BR>Balance weights are installed on the spinner cone, and<BR>engine is operating at the same speeds that during the<BR>initial run and vibration levels are recorded. Obviously,<BR>the vibration amplitudes change and are more or less<BR>important that the one recorded during the initial run.<BR>Second run<BR>Balance weights installed for the engine first run are<BR>removed and installed in different position 120° apart) ,<BR>Engine is run again at the same speeds that the earlier<BR>runs, and vibration levels are recorded.<BR>Once again, Vibration amplitudes change, and are more<BR>or less important that previous engine runs.<BR>Third run<BR>Balance weights installed for the engine second run are<BR>removed and installed in a different position (120° apart)<BR>from the second run. Engine is run again at the same<BR>speeds, and vibration levels are recorded.<BR>Once again, Vibration amplitudes change, and are more<BR>or less important that amplitudes recorded during<BR>previous engine runs depending on the position of<BR>unbalance.<BR>Engine runs analysis<BR>From the engine runs recorded data, a manual vectorial<BR>construction is performed to determine the amount of<BR>balance weight to install, and the position to install the<BR>weight. This is calculated using the different forms<BR>available within the Boeing Maintenance Manual.<BR>Weight is then installed on the engine rear spinner cone<BR>according to the analysis calculation.<BR>Final run<BR>The engine is operated to record the engine vibration<BR>amplitude, and to verify that the level is within limits.<BR>NOTE: If during engine run with test weights installed the<BR>vibration level is measured within limits, the fan trim<BR>balance procedure is finished.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 9<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>3 SHOT PLOT PHILOSOPHY<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 10<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Aircraft and engine preparation is to be performed prior<BR>to operation of the engine.<BR>To read vibration in mils, vibration equipment is to be<BR>installed. The vibration indicator in the flight compartment<BR>reads in units and is not possible to read vibration in mils.<BR>If the aircraft is not equipped with unbalance phase angle<BR>recording features, it is not possible to know if vibration is<BR>generated by the N°1 bearing vibration sensor or the<BR>FFCCV sensor. It isn't possible to read vibration in mils<BR>either.<BR>To obtain more information, install a selector switch<BR>which isolates the signals coming from the vibration<BR>sensors, and install the breakout cable. Disconnect the<BR>AVM signal conditioner from its support (Refer to the<BR>AMM 77-31-00), and connect the breakout cable to the<BR>electronic shelf connector. Route the breakout cable up<BR>to the flight compartment area and connect it with the<BR>selector switch.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 11<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>PREPARATION<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 12<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Initial run<BR>Prior to start the engine, a careful record of the actual<BR>balanced screws installed on the rear spinner cone must<BR>be performed. Record the configuration on the Balance<BR>screw location chart.<BR>Then start the engine, and bring it to stabilized thermal<BR>condition if the engine was shut down for more than 6<BR>hours. The stabilized engine thermal condition is<BR>obtained running the engine at 80% N1 for at least 5<BR>minutes.<BR>If the engine was not shut down the last 6 hours, stabilize<BR>the engine in idle for 3 minutes, and then slowly<BR>accelerate the engine until the takeoff N1 target of the<BR>day is reached.<BR>Important: Stop engine acceleration if the vibration level<BR>equals 4 units on the vibration gage or 8 mils scale on<BR>the indicator overlay.<BR>Stabilize the engine at the T/O N1 target (if you can<BR>reach this RPM) and record the vibration amplitude for<BR>both N°1 bearing sensor and FFCCV sensor. Selection<BR>of sensors output is selected through the selector<BR>switch.<BR>Decrease the engine speed to the next lower N1 speed<BR>target defined in the AMM, (now 93,7%) and record the<BR>vibration levels red from the N°1 bearing sensor and<BR>FFCCV sensor.<BR>Important: Wait engine EGT and N1 parameters to<BR>stabilize prior to record those data.<BR>Follow the same exact procedure to record vibration<BR>levels for the next lower speeds. (85%, 81%, 66%, and<BR>54%).<BR>Shut down the engine, and prepare balance weights for<BR>the next run called engine first run.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 13<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>ENGINE INITIAL RUN<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 14<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>First run<BR>Install three balance screws P05 instead of P07 balance<BR>screws installed on the rear spinner cone.<BR>You can now start the engine, stabilize it in idle. The<BR>engine warm up procedure (stabilization at 80% N1) is<BR>not needed.<BR>Repeat exactly the same running procedure that the<BR>initial run to record vibration amplitudes for both N°1<BR>bearing sensor and FFCCV sensor.<BR>Record the vibration amplitudes into the second column<BR>of the three shot plot worksheet form.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 15<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>ENGINE FIRST RUN<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 16<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Second run<BR>Remove the three P05 screws which have been installed<BR>during the last run, and replace them with P07 screws.<BR>120° apart from their latest position, install the three<BR>balance screws P05 instead of P07 balance screws .<BR>You can now start the engine, stabilize it in idle. The<BR>engine warm up procedure (stabilization at 80% N1) is<BR>not needed.<BR>Repeat exactly the same running procedure that the last<BR>run to record vibration amplitudes for both N°1 bearing<BR>sensor and FFCCV sensor.<BR>Record the vibration amplitudes into the third column of<BR>the three shot plot worksheet form.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 17<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>ENGINE SECOND RUN<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 18<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Third run<BR>Remove the three P05 screws which have been installed<BR>during the second run, and replace them with P07<BR>screws. Next install 120° from P05 second run position,<BR>install the next three balance PO5 screws after removing<BR>the P07 balance screws.<BR>Now start the engine, stabilize it in idle. The engine warm<BR>up procedure (stabilization at 80% N1) is not needed.<BR>Repeat exactly the same running procedure that the last<BR>run to record vibration amplitudes for both N°1 bearing<BR>sensor and FFCCV sensor.<BR>Record the vibration amplitudes into the fourth column of<BR>the three shot plot worksheet form.<BR>Shut down the engine and proceed to the next step.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 19<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>ENGINE THIRD RUN<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 20<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>Once all data have been accurately recorded,<BR>determinate the location and amount of weight to install<BR>on the rear spinner cone to correct the engine unbalance.<BR>Note: To facilitate the calculation, select only the speeds<BR>where the three highest vibration amplitudes from each<BR>sensor have been recorded in the initial run.<BR>Give an identification letter to each one of the recorded<BR>vibration amplitude;<BR>- A = highest vibration level<BR>- B = second highest vibration level<BR>- C = third highest vibration level<BR>for N°1 bearing sensor.<BR>- D = highest vibration level<BR>- E = second highest vibration level<BR>- F = third highest vibration level<BR>for the FFCCV sensor.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 21<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>3 SHOT PLOT EXERCISE<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 22<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>Represent the initial unbalance on a polar graph. Choose<BR>a correct scale size that will fit on the polar graph.<BR>Represent each of the 6 points A-B-C and D-E-F on a<BR>different polar graph to get accurate representation.<BR>For each point, draw one circle from the center of the<BR>polar graph. The radius of the circle you draw is equal to<BR>the vibration amplitude that was recorded for the point<BR>selected.<BR>Note: For training purposes, only one point (A)<BR>construction will be demonstrated in detail, the other<BR>points will be shown later.<BR>For the point A, the vibration amplitude equals to 6.5<BR>mils. First define a scale which suits the amplitudes for<BR>point A, and then draw a circle of radius 6.5 from the<BR>center of the polar graph.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 23<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 24<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>Represent the First engine run vibration behavior with<BR>the set of PO5 balance weights installed.<BR>To represent it, draw a circle which has the radius of the<BR>vibration level for the selected point (A), using the<BR>identical scale used the step earlier.<BR>For this example, the vibration level recorded for the<BR>point A was 4 mils, so, draw a circle with the radius<BR>taken from the scale.<BR>Its center is located at the intersection of the initial<BR>unbalanced condition circle and the radius passing from<BR>the center of the graph to the central balance screw<BR>position (here position 35).<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 25<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 26<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>Represent the second engine run vibration behavior with<BR>the set of PO5 balance weights installed.<BR>To represent it, you must draw a circle which has the<BR>radius of the Vibration level for the selected point (A),<BR>using the identical scale you used the step earlier.<BR>For this example, the vibration level recorded for the<BR>point A was 8.6 mils.<BR>Its center is located at the intersection of the initial<BR>unbalanced condition circle and the radius passing from<BR>the center of the graph to the central balance screw<BR>position (here position 23).<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 27<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 28<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>Represent the third engine run vibration behavior with<BR>the set of PO5 balance weights installed.<BR>To represent it, you must draw a circle which has the<BR>radius of the balance level recorded at the third run for<BR>the selected point for the (A).<BR>For this example, the vibration level recorded for the<BR>point A was 7.8 mils, so, with the scale, it is represented<BR>with a 47 mm radius circle.<BR>Its center is located at the intersection of the initial<BR>unbalanced condition circle and the radius passing from<BR>the center of the graph to the central balance screw<BR>position (here position 11).<BR>The scale used is: 6 mm for 1 mils of vibration.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 29<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 30<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>The resultant R for the point (A) is the vector which is<BR>drawn from the center of the polar graph, and the<BR>intersection of the 3 circles drawn for each run.<BR>NOTE: If during your construction, the 3 circles do not<BR>cross in one point, draw the vector from the center of<BR>the polar graph to the center of the common area of<BR>those 3 circles.<BR>For this point (A), according to the scale we used, the<BR>amplitude in mils equals 2.7 mils.<BR>The angle of this vector has to be measured from the<BR>vertical axis, so for this point (A), the angle equals 5<BR>degrees.<BR>Calculate the balance weight W6 corresponding to<BR>the point (A) using the formula.<BR>W6 = 831.8 x U0 (initial unbalance)<BR>R1 (calculated resultant for<BR>point A)<BR>For point (A), this is 831.8 x 6.5 = 2002 cm.g<BR>2.7<BR>The final calculation for the point (A) concerns the<BR>sensitivity. It represents how the additional weights<BR>PO5 added to the engine in 3 different positions (120 °<BR>apart) affect the balance condition of the engine for this<BR>particular speed.<BR>Sensitivity = 831.8 = 831.8 = 308<BR>R1 2.7<BR>Calculate and fill in the information for all the remaining<BR>points onto the corresponding form .<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 31<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 32<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>The angle of this vector has to be measured from the<BR>vertical axis, so for this point (A), the angle equals 5<BR>degrees.<BR>You must also calculate the balance weight W6<BR>corresponding to the point (A) using the formula The<BR>angle of this vector has to be measured from the vertical<BR>axis, so for this point (A), the angle equals 5 degrees.<BR>Calculate the balance weight W6 corresponding to the<BR>point (A) using the formula<BR>The next step is to represent graphically each calculated<BR>balance weight W6 for all the different points A, B, C, D,<BR>E, F onto one polar graph.<BR>Note: You must select a scale which permits you to draw<BR>each point onto the polar graph.<BR>For this example a scale of 1 cm for 500 cm.g is<BR>selected.<BR>Report each balance weight point at the correct angle<BR>onto the polargraph.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 33<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 34<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>Using the last polar graph fill out the form to calculate the<BR>maximum amplitude for each vector.<BR>To calculate it, you must graphically joint each point<BR>which is mentioned in the form, starting by AB, then AC,<BR>then AD, up to EF.<BR>Note: Once you measure the distance in between a and<BR>B, A and C, don't forget to transform this distance into<BR>moment weight using the same scale as used earlier 1<BR>cm corresponding to 500 cm.g.<BR>For vector AB:<BR>To fill out the first Sensitivity P1 column, get the<BR>information (point A) from the chart . To fill out the<BR>second Sensitivity P1, get the information (point B) from<BR>the chart.<BR>You just need to make the addition of those two columns<BR>to fill out the SP1+SP2 column.<BR>To calculate the amplitude (U), use the formula provided<BR>into the form which corresponds to the distance of the<BR>considered vector (AB) divided by the sum of the<BR>sensitivity you calculated in column SP1+SP2.<BR>Do the same for all the remaining vectors AC, AD, etc.<BR>Once all amplitudes (U) have been calculated, select the<BR>highest one to calculate the distance from P1.<BR>In this example, the selected one is corresponding to the<BR>vector AD, where the amplitude equals 2.623.<BR>Using the formula which is the amplitude multiplied by<BR>the sensitivity of the point A, we will find the distance<BR>from point A.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 35<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 36<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>On the polar graph you used earlier and using the same<BR>scale, report the distance you calculated onto the form,<BR>starting at the point A.<BR>Draw the vector from the center of the graph to this point,<BR>and measure it.<BR>Transform this distance into balance weight using the<BR>scale, and measure the angle from the vertical axis.<BR>Record this value on the form, this is what you need to<BR>balance the engine.<BR>In this example, the result is 1550 cm.g at 26°.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 37<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 38<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>In this example, the result is 1550 cm.g at 26°.<BR>Going to the balancing weight location form, find out the<BR>physical location of balancing weight position.<BR>In this example, the measured angle is 26°, so the<BR>calculated angle selection is the one in between 23 and<BR>27 degrees.<BR>The balancing weight must be centered into 2 screws<BR>positioned in 34 and 35.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 39<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 40<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Balancing weights calculation process<BR>Using the PO weight chart, find the balancing weight<BR>required centered into two screws in figure 514.<BR>Find on the right hand side column, the closest balance<BR>weight corresponding to the calculated balance weight<BR>needed.<BR>For this example, 1527cm.g is the closest to the 1550<BR>cm.g needed.<BR>Balance screws selection is mentioned on the horizontal<BR>line corresponding to the 1527 cm.g.<BR>For this example, 6 screws are needed, and they are:<BR>- 2 P06 screws<BR>- 4 P04 screws.<BR>To install them, number the screws from the horizontal<BR>centerline in counterclockwise direction, corresponding to<BR>the balance screws position Aft Looking Forward.<BR>In this example, install P06 screws in position 34 and 35,<BR>and P04 screws in position 32, 33, and 36 and 1.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 41<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 42<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THE 3 SHOT PLOT EXERCISE<BR>Maintenance Practice (3.E.a)<BR>Last Engine Run<BR>Remove the old balance screws and install the new<BR>balance screws at the correct position in the rear spinner<BR>cone.<BR>Start the engine and operate it at the same speeds as<BR>before on the run sheets.<BR>Record the vibration levels at the determined speeds and<BR>record them onto the vibration recording form.<BR>Check that all vibration levels are below the limits found<BR>in the AMM 71-00-00.<BR>This concludes the fan trim balance "3 shot plot"<BR>procedure.<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>Page 43<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION<BR>3 SHOT PLOT EXERCISE<BR>Page 44<BR>71-00-00 Aug 99<BR>CFM56-7B TRAINING MANUAL<BR>THIS PAGE INTENTIONALLY LEFT BLANK<BR>EFFECTIVITY 737-600/700/800/900/BBJ/COMBI/C40A<BR>CFMI PROPRIETARY INFORMATION

979199501 发表于 2011-4-12 00:13:29

回复 1# 航空 的帖子

LGR起落架部件项目培训大纲

kinran 发表于 2011-6-4 23:45:21

:victory: :victory:

bocome 发表于 2011-7-31 04:07:17

CFM56-7B TRAINING MANUAL ENGINE FAN TRIM BALANCE (3 SHOT PLOT)

chutiankuo0832 发表于 2011-8-24 22:37:36

好东西要学习

lsj_xd 发表于 2014-4-30 22:07:33

???CFM56-7B TRAINING MANUAL ENGINE FAN TRIM BALANCE (3 SHOT PLOT)

海青岛主 发表于 2014-7-22 08:49:07

学习学习~~~~~~~~~~

f214216709 发表于 2014-9-4 14:37:05

7B的资料哦  非常不错的

titanium 发表于 2016-4-16 13:55:09

啦啦啦啦啦
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