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Repair of CFM56 Bearings withReplacement of Components
Bearing Reconditioning
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1. Part numbers concerned
0
100
AR 593646; Los 0390874-42 32 CrMoV 13 (TW 2228.1)
-
-200
-100
.
-500
-400
-
idualStress,
MP Residual Stress Curve
-800
-700
-600Re
474-284-1-01A/01A min
474-284-1-01A/01A max
AR 593646; Los 0390874-42 Segm. 1
AR 593646; Los 0390874-42 Segm. 2
AR 593646; Los 0390874-42 Segm. 3
AR 593646; Los 0390874-42 Segm. 4
-1.000
-900
0,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0,09 0,10
Min. Customer Requirement
Distance from Surface, mmES 04-0126
Figure 1: Residual stress profile for the raceway
No. 4 Outer ring(deep-nitrated)
The CFM 56 #4R mainshaft bearing is highly stressed
during operation.
To increase the reliability of this bearing, major design
changes have been made.
The original design included an outer ring made from
M50 material.
The initial improvement was to add a stress profile
requirement for the raceway of the M50 outer ring.
To further improve the reliability, the outer ring material
was modified with nitrogen hardening and a specific
stress profile (see figure 1) for the raceway.
2. General
Overhaul of the CFM56 #4R mainshaft engine bearingwith
replacement of components (cage, rollers, outer ring)
1)
Upgrade (retrofit) by using an outer race of the new
configuration material
CFM56 -3/-5/-7 #4 R (Roller) 335-352-301-0
335-352-302-0
335-352-303-0
335-352-304-01)
335-352-305-01)
Engine Model Bearing Position Bearing Type Part Number
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Any re-work of the outer ring raceway (honing, polishing)
will change the stress profile and could lead to an outof limits
condition, with the possible consequence of a
reduced bearing reliability.
To ensure high reliability, FAG always replace the outer
ring by a new outer ring manufactured to the original
OEM approved process.
Our customers get more than a repaired bearing,
they have a repaired bearing which meets the
latestconfiguration.
3. Bearing Repair Procedure
Why take the risk of having such a highly stressed
bearing repaired by a non OEM approved repair source,
with a non OEM approved repair procedure, when you
can get the bearing repaired to the latest bearing
configuration, which meets all the OEM requirements.
4. Conclusion
FAG Aerospace always replace the outerring with a newly
manufactured part.
Outer ring:
Replaced with newly manufactured ring during repair
Rollers:
Replaced with newly manufactured components during repair
Cage:
Replaced with newly manufactured components during repair
Inner ring:
Re-manufactured
and re-inspected
per SNECMA instructions
Figure 2: The following pictures illustrate the condition of the
CFM56 #4R bearing assembly before and after repair
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FAG Aerospace GmbH & Co. KG
Bearing Reconditioning
Georg-Schfer-Str. 30
97421 Schweinfurt
GERMANY
Tel: +49 9721 91 4108
Fax: +49 9721 91 3645
FAG Aerospace Inc.
Bearing Reconditioning
151 Wright Blvd.
PO Box 640
Stratford, Ontario, N4Z 1H3
CANADA
Tel: +519-271-3231 x280
Fax: +519-273-8514
Every care has been taken to ensure the
correctness of the information contained
in this publication but no liability can
be accepted for any errors or omissions.
We reserve the right to make technical changes.
Schaeffler KG 2009, August
This publication or parts thereof may not
be reproduced without our permission.
AC 09 116 GB-D200908.15/PrintedinGermany
FAG Aerospace Services
Bearing Reconditioning
200 Park Ave
PO Box 2449
Danbury, Connecticut 06813
USA
Tel: +203-794-8494
Fax: +203-744-3756
FAA Repair Station No. F2GY854JEASA Repair Station No.
DE.145.0127CAAC Repair Station No. F04900413
Air Transport Canada Repair StationAMO #: 41-99
FAA Repair Station No. BCYR313X
FAG Aerospace GmbH & Co. KG
Dept. SX/FAB-LAR
Georg-Schfer-Str. 30
97421 Schweinfurt (Germany)
Tel: +49 9721 - 91 4108Fax: +49 9721 - 91 3654
E-mail: [email protected]
www.fag.com
