System for suspending two modules of a propulsion unit

Abstract

The invention relates to a system for suspending two modules of a propulsion unit, such as two fan modules, said system comprising a pylon (28) and a rudder bar (30). One part (30) of the rudder bar is hinged to the pylon, while the opposing ends thereof are hinged to connecting rods (34, 36). The system also comprises a torque bar (40) which has an elongate shape and is mounted on the pylon such that it can pivot about an axis substantially parallel to an axis (B) of elongation of the torque bar, the opposing ends (42) of said bar being secured on each side of the above-mentioned part of the rudder bar.

Claims

1. A suspension system for two modules of a propulsion unit, comprising: a pylon, a first and a second link rods, crossbar, said crossbar comprising a portion hinged on said pylon, said crossbar comprising first and second opposite ends, said first end being hinged on said first link rod and said second end being hinged on said second link rod, wherein it further comprises a torque reaction bar, said torque reaction bar being of elongated shape and being mounted swivelling on said pylon about an axis substantially parallel to an extension axis (B) of said torque reaction bar, said torque reaction bar comprising first and second opposite ends fixed to said crossbar, on either side of said portion of said crossbar.

2. The suspension system according to claim 1, wherein said crossbar is hinged by swivel joints to said pylon and to said first and a second link rods.

3. The suspension system according to claim 1, wherein said first and second opposite ends of the torque reaction bar are fixed to said crossbar near said first and second opposite ends of the crossbar.

4. The suspension system according to claim 1, wherein said crossbar extends substantially parallel to the extension axis (B) of said torque reaction bar, or has an elongated shape whose extension axis is substantially parallel to the extension axis of said torque reaction bar.

5. The suspension system according to claim 1, wherein said portion of the crossbar is a middle portion or is located mid-way from said first and second opposite ends of the crossbar.

6. The suspension system according to claim 1, wherein said portion of the crossbar is a portion located at a distance D1 from said first opposite ends of the crossbar and at a distance D2 from said second opposite end of the crossbar, D1 being different from D2.

7. The suspension system according to claim 1, wherein said crossbar comprises two supporting arms of said torque reaction bar that comprise holes for mounting said torque reaction bar.

8. The suspension system according to claim 6, wherein a distance L1 between said first and second opposite ends of the crossbar is greater than a distance L2 between said first and second ends of the torque reaction bar, which is itself greater than a distance L3 between said supporting arms of the crossbar, the distances being measured along said extension axis (B) of the torque reaction bar.

9. A propulsion unit, comprising: a gas generator, at least two fan modules, wherein it is equipped with a suspension system comprising: a pylon, first and second link rods, a crossbar, said crossbar comprising a portion hinged on said pylon, said crossbar comprising first and second opposite ends, said first end being hinged on said first link rod and said second end being hinged on said second link rod, wherein it further comprises a torque reaction bar, said torque reaction bar being of elongated shape and being mounted swivelling on said pylon about an axis substantially parallel to an extension axis of said torque reaction bar, said torque reaction bar comprising first and second opposite ends of said bar being fixed to said crossbar, on either side of said portion of said crossbar, and wherein said first and a second link rods are hinged respectively on said at least two fan modules.

Description

DESCRIPTION OF THE FIGURES

(1) The invention will be better understood and other details, features and advantages of the invention will become clearer on reading the following description provided as a non-limiting example and referring to the appended drawings, in which:

(2) FIG. 1 is a very schematic view of a propulsion unit with two fan modules;

(3) FIGS. 2 and 3 are very schematic views of systems for suspension of fan modules of a propulsion unit;

(4) FIG. 4 is a very schematic view of a suspension system according to the invention;

(5) FIGS. 5 to 8 are very schematic views similar to that in FIG. 4 and illustrate the operating principle of the system;

(6) FIG. 9 is a very schematic side view of the system and illustrates the operating mode in FIG. 8; and

(7) FIGS. 10 and 11 are schematic perspective views of one embodiment of the suspension system according to the invention.

DETAILED DESCRIPTION

(8) FIG. 4 shows a non-limiting embodiment of the invention that relates to a system 32 for suspension of two modules of a propulsion unit that comprises at least one gas generator and at least one fan.

(9) In the case when the propulsion unit comprises two fan modules, as shown in FIG. 1, the suspension system 32 may be used for suspending these two modules on an aircraft.

(10) The system 32 essentially comprises a pylon 28, a crossbar 30, thrust-reacting link rods 34, 36, and a torque reaction bar 40.

(11) The pylon 28 has an elongated shape and one of its longitudinal ends is in this case hinged on a portion 30 of the crossbar 30, which is either a middle portion of the crossbar or some other portion of the crossbar as is the case in the example shown. This portion 30 takes up the thrust forces of the two fan modules.

(12) The crossbar 30 also has an elongated shape with an extension axis designated A. Each of its longitudinal ends is hinged on one end of at least one link rod 34, 36, whose opposite end is intended to be hinged on one of the fan modules.

(13) The portion 30 of the crossbar 30 is located at a distance D1 from the end of the crossbar 30 connected to the link rod 34, and at a distance D2 from the opposite end of the crossbar 30 connected to the link rod 36. In the example shown, D1 is greater than D2. The means 38 for articulation of the pylon 28 to the crossbar 30 and of the crossbar to the link rods 34, 36 are preferably of the swivel type.

(14) The torque reaction bar 40 has an elongated shape whose extension axis is designated B and is substantially parallel to the axis A.

(15) The bar 40 is fixed rigidly to the crossbar 30 and is mounted by a swivel joint on the pylon 28. The bar 40 extends in the vicinity of the crossbar 30 and here it has a length L2 less than that L1 of the crossbar 30. The longitudinal ends 42 of the bar 40 are fixed on the crossbar 30 on either side of the portion 30, and near the ends of the crossbar 30 in the example shown. Preferably, but in a non-limiting manner, the rigid link between the crossbar 30 and the bar 40 is made by means of a male-female joint. In particular, as is illustrated in FIGS. 10 and 11, each longitudinal end 42 of the bar 40 has a section of H shape or U shape, the two branches of which grip the body of the crossbar 30, here of rectangular section. Of course, the crossbar 30 could have a body of H-shaped or U-shaped section with two branches fitting round a fork provided on the longitudinal end 42. The male-female joint is of the surface bearing type.

(16) The pylon 28 comprises two arms 44 for supporting and mounting the bar 40. Each arm 44 comprises a hole 46 for passage of the bar 40 and guidance in rotation about the axis B. In the case when the bar 40 is of a cylindrical shape, each arm 44 could comprise a tubular portion 48 defining a cylindrical internal surface for guiding the corresponding arm, as can be seen in the more concrete example in FIGS. 10 and 11. The pylon 28 supports the gas generator via the inlet housing and the exhaust housing of the latter by means of suspensions 31 arranged upstream and downstream of the pylon 28. The suspensions 31 comprise sets of link rods generally arranged respectively in planes transverse to the longitudinal direction of the pylon 28.

(17) In the embodiment in FIGS. 10 and 11, each link rod 34, 36 is of an elongated shape and comprises an attachment fork 50 at each of its longitudinal ends. The link rods 34, 36 extend in a plane approximately containing the crossbar 30, and therefore parallel to the axes A and B. Each fork 50 comprises two lugs, between which the corresponding end of the crossbar 30 extends. The lugs of each fork 50, for example, carry a pin that passes through a bore in a swivel housed in a spherical housing of the corresponding end of the crossbar. The same type of swivel joint may be provided between the pylon 28 and the portion 30 of the crossbar 30. The pylon 28 may thus comprise a fork in which the portion 30 is inserted and mounted by a swivel joint.

(18) Each link rod 34, 36 hinged on a fan module may be offset (not parallel) relative to the axis of the gas generator. The offset angle may be between 5 and 15.

(19) From now on reference will be made to FIGS. 5 to 9, which illustrate the operating principle of the system according to the invention.

(20) FIG. 5 shows the system in equilibrium, i.e. when P1.Math.D1=P2.Math.D2 with P1 and P2 denoting the respective thrusts of the fan modules to which the link rods 34, 36 are connected. Thus, there is minimum torsion in the bar 40. It should be noted that the relation P1.Math.D1=P2.Math.D2 is optimum and desired. In fact, variations in the manufacture of the fan modules and the different operating conditions of the fans mean there is residual torsion, so that the result is of the order of +/10%.

(21) FIG. 6 illustrates the case when a perturbation P occurs. In this case, a torque C1 is applied to the crossbar 30, which rotates about the pivot point (of the swivel joint of the crossbar 30 to the pylon 28) by an angle on the pylon.

(22) As is shown in FIGS. 7 to 9, the bar 40 makes it possible to limit the displacements by applying a torque C2 that opposes the displacements caused by torsion of the bar 40. The quantities .Math.P and p.Math.P represent the forces caused by the reaction of the bar 40 (opposing torque C2 equal to the induced torque C1).

(23) For this purpose, the torque reaction bar 40 is made of high-alloy steel so as to take up the forces. Some other material additionally comprising properties of heat resistance may of course be used for making the bar 40.

(24) A propulsion unit with fan modules with different thrust may thus be suspended without technical difficulty on a structural element of the aircraft.