72-31-02
 ALL  ú ú C03 Page 418 ú Nov 12/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
 8)

////////////////////////A / /
CFM56 ENGINES
737-300/400/500/ /MAINTENANCE MANUAL ////////////////////////
d)  Draw the resultant vector from the origin (center of the graph) to the intersection of the vectors.
 e)  Use the above resultant vector and the next vector F3 to find the new intersection and the new resultant vector.
 f)  Do the last step again, each time with the resultant vector from the last step and the next vector F#, until all the vector have been averaged and one resultant vector is found.
 g)  The resultant vector FR gives the the weight and the location for the balance screw.
 1.  In this example, FR is approximately 87 gram-inches
_ (221 gm-cm) and installed near the balance screw No. 18.
Install the balance screws as follows:
 NOTE: When the resultant imbalance direction is between
____ two holes, you must put the screw (found from the fifth column of Fig. 405 and 406) in the nearest hole.
 a)  From Fig. 405, one P03 screw will give a correction which will balance the fan back to its initial balance condition.
 CAUTION: MAKE SURE THE FAN BLADES DO NOT TOUCH THE TOOLS.
_______ CRACKS CAN OCCUR IN THE BLADES. DO NOT USE RATCHETING TOOLS WHEN YOU REMOVE OR INSTALL THE BALANCE SCREWS.
 b)  Remove the old screws.
 NOTE: If the old screws are not type P07, you must
____ calculate the new screw type. Do the steps for the static imbalance correction on a spinner with balance screws other than P07.
 The balance screws have numbers (P01-P02-P03-P04-P05-P06-P07) which show the balance-weight of the screw (Fig. 404). If you cannot get the number from the screw because of erosion, use Fig. 404 to get the relation between the screw number and the screw length.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 72-31-02
 ALL  ú ú C02 Page 419 ú Mar 15/97
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / /
CFM56 ENGINES
737-300/400/500/ /MAINTENANCE MANUAL ////////////////////////
c)  Install the new balance screws.
 NOTE: The torque value for the balancing screws is
____ 70-75 pound-inches (8.0-8.5 Newton meters).
 d)  Tighten the screws to to 65-75 pound-inches (7.5-8.5 Newton meters).
 (f) Do these steps to do a static imbalance correction on a spinner with the balance screws other than P07. 1) The steps that follow is an example of a correction: a) Think you are to install a balance weight Fc = 230 gram-inch (584.2 gm-cm) in the direction toward the balance screw No. 26 on the spinner and you have the screws P03 in screw positions No. 19 and 20, and P05 in screw position No. 24. b) The two screws P03 have a total moment-weight F1 of 175 gram-inch (444.5 gm-cm) along an axis between the two screws. c) Screw P05, installed in position No. 24, has a moment-weight F2 of 138 gram-inch (350.5 gm-cm) along an axis through the screw location.
 d)  A vector summation of the three balance screws has a resultant, F3, of approximately 290 gram-inches
 (736.6 gm-cm).
 e)  Fc and F3 have a vector summation, Ft, of 490 gram-inch (1244.6 gm-cm) along an axis between the balance screws No. 23 and 24.
 f)  From the Figs. 405 and 406, three P06 balance screws give a total moment-weight of 494 gram-inches (1254.76 gm-cm).
 g)  Remove the old screws and install three P06 balance screws in positions No. 22, 23 and 24.
 h)  A vibration survey (AMM 71-00-00/501) can be done at the operator's discretion when new blade(s) are installed or when the same fan blade set is installed again. The survey results will show if it is necessary to do the fan trim balance or if the installation is correct (AMM 72-31-00/501).
 NOTE: If the resultant imbalance FR (the resultant
____ which defines the weight and location for the balance screw) is greater than 157.5 g in (400cm g), do a vibration survey after the static correction (AMM 71-00-00/501). Refer to Figure 401 (Customer Convenience).
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 72-31-02
 ALL  ú ú C03 Page 420 ú Jul 12/99
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：737-300 400 500 AMM 飛機維護手冊 ENGINE 發動機 1(137)