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US005474258A
United States Patent (19) 11 Patent Number: 5,474,258
Taylor et al. (45) Date of Patent: Dec. 12, 1995
54 MOUNTING ARRANGEMENT FOR A GAS 4,044,973 8/1977 Moorehead ............................... 244.54
TURBINE ENGINE 5,277.382 1/1994 Seelen et al. ............................. 244/54

(75) Inventors: Mike C. Taylor; Carl Hodgkinson; FOREIGN PATENT DOCUMENTS

Kenneth W. Wright; Derek Perry, all 22.37060 1/1975 France.
of Derby, England
73) Assignee: Rolls-Royce plc, London, England Primary Examiner Galen L. Barefoot
21 Appl. No.: 244,252 Attorney, Agent, or Firm-Cushman Darby & Cushman
22, PCT Filed: Aug. 28, 1992 57 ABSTRACT
86 PCT No.: PCT/GB92/O1576 A gas turbine engine 10 is suspended via a casing 15 from
S371 Date: May 20, 1994 a pylon 12 by a front mount 20 and a rear mount 40. The
front mount 20 comprises a bracket 22, having a plurality of
S 102(e) Date: May 20, 1994 pins 26,28 and 30 integral therewith, which is bolted to the
87 PCT Pub. No.: WO93/11041 underside 11 of the pylon 12. The first pin 26 engages an
annular flange 16 around the casing 15 to support the engine
PCT Pub. Date:Jun. 10, 1993 10 in a vertical plane. Any vertical loads act peripherally of
(30) Foreign Application Priority Data the casing 15 through the annular flange 16 to minimise the
distortion of the casing 15. The second pin 28 engages with
Nov. 25, 1991 GB United Kingdom ................... 9125O1 the casing 15 directly to prevent axial and lateral movement
(51) int. Cl. .......................................... B64D 27/00 of the engine 10 relative to the pylon 12. The third pin 30 is
provided as a failsafe. In normal operation the third pin 30
52 U.S. Cl. ............................ 244/54; 248/554; 60/39.31 carries no load, however if the first pin 26 should break the
58 Field of Search ..................................... 244/53 R, 54; third pin 30 then supports the engine 10 in a vertical plane.
60/39.31; 248/554, 555,556, 557 Any vertical loads then act peripherally of the engine casing
15 through an annular flange 18.
56) References Cited
U.S. PATENT DOCUMENTS
3,561,707 2/1971 Strock ..................................... 248/554 4 Claims, 3 Drawing Sheets
U.S. Patent Dec. 12, 1995 Sheet 1 of 3 5,474,258
U.S. Patent Dec. 12, 1995 Sheet 2 of 3 5,474,258
U.S. Patent Dec. 12, 1995 Sheet 3 of 3 5,474,258
 5,474,258
1. 2
MOUNTING ARRANGEMENT FOR A GAS pylon 12. The bracket 22 is provided with a number of
TURBINE ENGINE integral pins 26, 28 and 30, shown in FIG. 3, which engage
the engine casing 15.
The present invention relates to a mounting arrangement A first pin 26 (FIG. 2) at the upstream end 21 of the
by which a gas turbine engine is attached to an aircraft. In bracket 22 engages a link 25 which is attached by plates 27
particular it relates to a mounting arrangement suitable for to the annular flange 16 around the engine casing 15. The
connecting a gas turbine engine to a pylon of an aircraft first pin 26 supports the engine 15 in the vertical plane and
wing. any vertical loads which are generated by the weight of the
According to the present invention a mounting arrange engine 10 act through the annular flange 16. The vertical
ment for a gas turbine engine having a casing provided with O loads are not therefore concentrated at specific points on the
an at least one annular flange comprises a support member engine casing 15 but act peripherally thereof. Distortion of
for attachment to an aircraft structure from which the engine the casing 15 is thus substantially minimised.
is to be mounted, the support member having a first con A second pin 28 on the underside 24 of the bracket 22
engages the engine casing 15 directly (FIG. 4). The second
nection means which engages the at least one annular flange pin 28 is located in a spherical joint 27 which is attached to
on the engine casing to support the engine in a vertical plane, 15 the engine casing 15 by a bushing 29. The spherical joint
the vertical loads acting peripherally of the engine casing allows angular movement of the engine 10 relative to the
through the at least one annular flange, second connection front engine mount 20.
means which engages the engine casing directly to prevent In operation the thrust of the engine 10 puts an equal and
axial and lateral movement of the engine relative to the opposite reaction on the engine 10 which if unrestrained
aircraft structure and a third connection means which in 20 would move axially relative to the pylon 12. The second pin
normal operation carries no load unless the first connection 28 acts as a thrust link to prevent this axial movement of the
means fails whereby the third connection means engages engine 10 relative to the pylon 12. The second pin 28 also
with a further annular flange on the engine casing to support prevents lateral movement of the engine 10 from side to
the engine in a vertical plane, the vertical loads acting side.
peripherally of the engine casing through the further annular 25 A third pin 30 at the downstream end 23 of the bracket
flange, characterised in that the first, second and third 22 is provided as a failsafe feature. In normal operation this
connection means are an integral part of the support member third pin 30 carries no load due to a clearance 31 between the
and the support member and the connection means are split third pin 30 and a link 32 which is attached by lugs to the
in a direction parallel to the longitudinal axis of the engine annular flange 18 around the engine casing 15. In the event
to render them damage tolerant. 30 however that the first pin 26 carrying the vertical loads of the
Preferably the connection means are pins. The first pin engine 10 should break the weight of the engine 10 is carried
may be located in a number of links attached to the annular by the third pin 30. When the first pin 26 breaks the weight
flange which disperse the load to a number of points on the of the engine 10 causes the engine 10 to fall until the third
annular flange. pin 30 comes into contact with the link 32 attached to the
The connection means are preferably coated with a wear 35 annular flange 18. The third pin 30 then supports the engine
resistance coating, such as tungsten carbide cobalt, which 10 in a vertical plane. The vertical loads act peripherally of
reduces the amount of wear. the engine casing 15 through the annular flange 18 to
The mounting arrangement is for use on a gas turbine minimise distortion of the engine casing 15.
engine which is also provided with a connection means In the preferred embodiment of the present invention the
which prevents rotation of the engine relative to the aircraft 40 bracket 22 and pins 26, 28 and 30 are split into two halves
structure from which the engine is mounted. The aircraft in a direction parallel to the longitudinal axis of the engine.
structure from which the engine is mounted is preferably a The split renders the front mount 20 damage tolerant by
pylon attached to the main beam of an aircraft wing. preventing cracks propagating from one half of the mount 20
The present invention will now be described with refer to the other half. The fact that the bracket 22 is split into two
ence to the accompanying drawings in which: 45 halves also assists in assembly of the mount 20. The two
FIG. 1 is a diagrammatic view of a gas turbine engine halves of the mount 20 are held together by bolts 35, FIG.
having a mounting arrangement in accordance with the 3, which are inserted through bolt holes 34 shown in FIGS.
present invention. 4.
FIG. 2 is an enlarged pictorial view of the front engine The bracket 22 and pins 26, 28 and 30 are coated with a
mount shown in FIG. 1. 50 wear resistant coating, such as tungsten carbide cobalt,
FIG. 3 is a plan view of the front engine mount shown in which extends the life of the mounting by reducing the
FIG. 2 when viewed in the direction of arrow A. amount of wear.
FIG. 4 is a part cross-sectional view of the front engine The bracket 22 is reinforced by strengthening ribs 33 and
mount shown in FIG. 3 when viewed in the direction of is provided with a number of dowel holes 31, FIG. 3,
arrow B. 55 through which dowels 39 (FIG. 4), are inserted. The dowels
Referring to FIG. 1 a gas turbine engine generally 39 are inserted to ensure accurate location of the bracket 22
indicated at 10 is secured to an aircraft wing (not shown) via relative to the pylon 12.
a pylon 12. The gas turbine engine 10 comprises an engine The engine 10 is suspended from the downstream portion
casing 15 which encloses a core engine of generally well 14 of the pylon 12 by a conventional rear mount 40. The rear
known type. The engine casing 15 comprises a number of 60 mount 40 connects the engine 10 via the engine casing 15 to
consecutive sections which are bolted together at annular the underside 11 of the downstream end 14 of the pylon 12.
flagged joints 16 and 18. The rear mount 40 comprises three links which act in
The engine 10 is suspended from the pylon 12 in con conventional manner to restrain any rotational movement of
ventional manner wherein the engine casing 15 is secured to the engine relative to the pylon 12.
the pylon 12 by a front mount 20 and a rear mount 40. 65 We claim:
The front mount 20 comprises a bracket 22 which is 1. A mounting arrangement for a gas turbine engine (10)
bolted to the underside 11 of the upstream end 13 of the having a casing (15) provided with an at least one annular
 5,474,258
3 4
flange (16) comprising a support member (22) for attach part of the support member (22) and the support member
ment to an aircraft structure (12) from which the engine (10) (22) and connection means (26,28 and 30) are split in a
is to be mounted, the support member (22) having a first direction parallel to the longitudinal axis of the engine (10)
connection means (26) which engages the at least one to render them damage tolerant.
annular flange (16) on the engine casing (15) to support the 2. A mounting arrangement as claimed in claim 1 in which
engine (10) in a vertical plane, the vertical loads acting the connection means (26, 28 and 38) are pins.
peripherally of the engine casing (15) through the annular 3. A mounting arrangement as claimed in claim 1 in which
flange (16), a second connection means: (28) which engages
the engine casing (15) directly to prevent axial movement of the first connection means (26) engages a number of links
the engine (10) relative to the aircraft structure (12) and a 10 (25 and 27) which are attached to the annular flange (16) on
third connection means (30) which in normal operation the engine casing (15) and which distribute the vertical loads
carries no load unless the first connection means (26) breaks acting thereon to a number of points on the annular flange
whereby the third connection means (30) engages with a (16).
further annular flange (18) on the engine casing (15) to 4. A mounting arrangement as claimed in claim 1 in which
support the engine (10) in a vertical plane, the vertical loads 15 the connection means (26, 28 and 30) are coated with a wear
acting peripherally of the engine (15) casing through the resistant coating to reduce the amount of wear.
further annular flange (18) characterised in that the first (26),
second (28) and third (30) connection means are an integral ck sk. : :k sk