AIRCRAFT TURBOMACHINE SUSPENSION SYSTEM WITH DOUBLE BALL LINKAGE AND SLIDING PIVOT

Abstract

This aircraft turbomachine suspension system comprises a set of connecting rods (25), each including connecting means (26, 27) for attaching the system between a turbomachine housing (22, 23) and an aircraft component. Each connecting rod (25) includes at one end a ball joint (26) and at the opposite end a ball joint (27) and a sliding pivot joint (28). Figure for the abbreviation: Fig 4

Description

Title of the invention: SUSPENSION SYSTEM FOR AIRCRAFT TURBOMACHINE A DOUBLE BALL JOINT AND SLIDING PIVOT technical field

[0001] The present invention relates to the field of turbomachines used for the propulsion of an aircraft and, more particularly, the attachment of a turbomachine to an element of the aircraft. Previous techniques

[0002] In a known manner, a turbomachine is intended to provide the thrust necessary for the propulsion of an aircraft. It classically comprises, from upstream to downstream, considering the direction of an airflow admitted into the turbomachine, a fan allowing to accelerate the airflow admitted into the turbomachine and comprising blades generally extending in the same plane transverse to the axis of the turbomachine, at least one compressor, a combustion chamber and at least one turbine to drive the compressor in rotation.

[0003] Attaching an aircraft turbomachine to an aircraft component is carried out in the prior art by means of a suspension system comprising a clevis including load-bearing connecting rods fixed on one side to a turbomachine casing and on the other side to a coupling fixed to a pylon linked to the aircraft component.

[0004] An example of an embodiment of such a suspension system is illustrated in [Fig. 1] which illustrates an aircraft turbomachine, designated by the numerical reference 1, comprising a casing 2, for example an inter-compressor casing, which is suspended from a mounting pylon 3 by means of a set of straight or boomerang-shaped connecting rods 4 linked by ball joints, such as 5, to the casing 2, on the one hand and to a coupling 6 fixed to the pylon 3, on the other hand.

[0005] According to another arrangement visible in figures 2 and 3, the turbomachine casing 2 is suspended by means of a set of centering rods 7 comprising a first end 8 connected by a ball joint to the turbomachine casing 2 and an opposite end 9 connected by a ball joint to a nacelle 10 connected to the mounting pylon 3.

[0006] In [Fig. 3], which corresponds to the implementation method of [Fig. 2], the system of The turbomachine suspension is attached to the exhaust housing or TRF (TRF being the Anglo-Saxon acronym for "Turbine Rear Frame") of the turbomachine. The TRF housing comprises an inner ferrule 11 and an outer ferrule 12, the suspension system comprising centering rods 7 linked to the outer ferrule 12 and to the nacelle.

[0007] In aircraft turbomachinery, it is generally desirable to constrain the transverse translations, i.e. perpendicular to the axis of the engine, and the rolling moment, coaxial with the engine of the turbomachine casing with respect to the pylon.

[0008] Suspension systems according to the prior art are likely to generate undesirable stresses in the turbomachine casing, particularly under the action of the connecting rods, these stresses being likely to cause casing ovalization, eccentricity of the load-bearing bearings, or even localized punching of the casing. Description of the invention

[0009] The aim of the invention is therefore to overcome these drawbacks and to propose a suspension system for aircraft turbomachinery which reduces the stresses in the casing, in particular by allowing an additional degree of freedom.

[0010] The invention therefore relates to a suspension system for an aircraft turbomachine, comprising a set of connecting rods, each comprising means for attaching the system between a housing of the turbomachine and an element of the aircraft.

[0011] Each connecting rod includes at one end a ball joint and at the opposite end a ball joint and a sliding pivot joint.

[0012] Advantageously, the suspension system includes damping means.

[0013] For example, the damping means are fluid damping means.

[0014] In one embodiment, the sliding pivot joint includes a stop to limit the sliding of the connecting rod.

[0015] The invention also relates to an aircraft turbomachine comprising a suspension system as defined above. Brief description of the drawings

[0016] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0017] Figures [Fig.1], [Fig.2] and [Fig.3], which have already been mentioned, schematically illustrate a turbomachine equipped with a suspension system according to the prior art;

[0018] Fig. 4 schematically illustrates a turbomachine equipped with a suspension system according to the invention;

[0019] Fig. 5 illustrates an example of an embodiment of the stop suspension system;

[0020] Figure 6 illustrates an example of an embodiment of the suspension system comprising means of depreciation; and

[0021] Figure 7 illustrates an example of the implementation of damping means integrated into the suspension system. Detailed description of at least one embodiment

[0022] Reference will be made to [Fig.4] which illustrates a turbomachine 20 equipped with a suspension system 21 according to the invention.

[0023] The invention relates essentially to the suspension system, only the part of the turbomachine 20 to which the suspension system is attached has been illustrated in [Fig.4],

[0024] A turbomachine extends along a turbomachine axis X and allows an aircraft to be propelled from an airflow entering the turbomachine and circulating from upstream to downstream, the terms upstream and downstream being defined with respect to the turbomachine axis X, considering the direction of the airflow in the turbomachine.

[0025] In a known manner, the turbomachine comprises, from upstream to downstream, a blower and a gas generator comprising a low pressure compressor, a high pressure compressor, a combustion chamber, a high pressure turbine and a low pressure turbine.

[0026] The low-pressure compressor, together with the low-pressure turbine to which it is connected by a turbine shaft, forms a low-pressure (LP) unit that drives the blower in rotation. The high-pressure compressor, together with the high-pressure turbine to which it is connected by a shaft, forms a high-pressure (HP) unit.

[0027] The fixed structural components of the turbomachine include in particular an inlet casing located at the inlet of the gas generator, an inter-compressor casing, located between the low pressure compressor and the high pressure compressor, and a TRF exhaust casing directly at the outlet of the low pressure turbine.

[0028] The turbomachine is supported by a suspension system 21 attached to the turbomachine housing, in particular to the TRF housing comprising an inner ferrule 22 and an outer ferrule 23, and to the nacelle 24 attached to an element of the aircraft, for example under a wing.

[0029] The suspension system consists of a set of centering rods, such as 25, arranged between the turbomachine and the aircraft element, in particular between the TRF casing of the turbomachine and the nacelle and regularly distributed around the turbomachine.

[0030] The nacelle 24 is a structural nacelle, in that it allows centering of the turbomachine housing by means of the centering rods 25.

[0031] The centering rods include at their mutually opposite ends means for connecting to the TRF housing and the nacelle, respectively. The connecting means include ball joints 26, 27 and a sliding pivot joint 28.

[0032] As illustrated in [Fig.4], each connecting rod includes at one end a ball joint 26, by which it is fixed to the outer ferrule of the housing, and at its opposite end a ball joint 27 associated with a sliding pivot joint 28.

[0033] The upstream end of the connecting rod is provided with a ball joint 26. The opposite downstream end is provided with a ball joint 27 and then a sliding pivot joint.

[0034] The axis of the sliding pivot joint is parallel to the X axis of the turbomachine.

[0035] Compared to a two-ball joint, in which the forces applied in The connecting rod axis is returned to the crankcase and to the aircraft component to which the suspension system is attached. A double ball joint combined with a sliding pivot joint prevents the blocking of uniform expansions of the centering rods or differential expansions between the connecting rods, each connecting rod being free to move along the sliding pivot joint, in the axis of the joint, when the engine and the connecting rods expand thermally.

[0036] However, the axial-radial translations of the downstream end of the connecting rod are not blocked. The degrees of freedom of each connecting rod make the suspension system robust and reliable in the event of different axial and radial expansions, during engine heating or cooling.

[0037] The suspension system, which includes a double ball joint coupled to a sliding pivot joint, allows radial movement of the housing, which implies a lesser absorption of radial forces, compared to a double ball joint system.

[0038] With reference to figures 5 and 6, it is therefore advantageous, in one embodiment, for the suspension system to be equipped with suspension means comprising a double ball joint 26, 27 coupled to a sliding pivot link 28 with stop or with shock absorber.

[0039] In the embodiment of [Fig.5], the sliding pivot joint 28 is provided with a stop 29.

[0040] Such a stop prevents the sliding pivot from sliding to the vertical of the connecting rod of the housing, and therefore prevents the housing from moving radially. Thus, the operating or off-center loads are fully absorbed.

[0041] In the embodiment of [Fig.6], the sliding pivot joint is provided with damping means.

[0042] These damping means are for example fluid damping means, for example oil damping, capable of filtering high frequency loads and thus allowing the sliding pivot to take over the loads generated during aircraft maneuvers.

[0043] For example, the damping means comprise a cylinder 30 filled with oil or a suitable fluid, for example linked to the nacelle and comprising two communicating chambers between which a calibrated passage 31 is provided, and a plunger piston 32 linked, for example, to a connecting rod, a return spring 33 being associated with the piston. The partition 34 separating the two chambers of the cylinder 30 can advantageously constitute a stop for the piston.

[0044] It will be noted that the invention which has just been described, which uses connecting means comprising a ball joint 26 and a sliding pivot joint 27, applies to any suspension system comprising any number of centering rods.

[0045] Furthermore, the invention is not limited to a suspension system used for centering a TRF housing but also applies to other attachment points located on the housing of the turbomachine.

Claims

Demands

1. Suspension system for aircraft turbomachine, comprising a set of connecting rods (25) each comprising connecting means (26, 27) for fixing the system between a housing (22, 23) of the turbomachine and an element of the aircraft, characterized in that each connecting rod (25) comprises at one end a ball joint (26) and at an opposite end a ball joint (27) and a sliding pivot joint (28).

2. Suspension system according to claim 1, comprising damping means (30, 31, 32).

3. Suspension system according to claim 2, wherein the damping means are fluid damping means.

4. Suspension system according to any one of claims 1 to 3, wherein the sliding pivot joint includes a stop (29) for limiting the sliding of the connecting rod.

5. Aircraft turbomachine comprising a suspension system according to any one of claims 1 to 4.

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