EP2630335B1 - Hydraulic device for changing the pitch of a propeller - Google Patents

Description

The present invention relates to a hydraulic device of a propeller pitch change control device.

The field of the invention is that of systems provided with a propeller, such as a wind turbine, an industrial fan, but also turbomachines and turbojet engines provided with a fan comprising a plurality of blades or blades at angles of variable setting.

In a known manner, a turbomachine comprises one or more stages of variable pitch vanes which are mounted between rotor wheels of a compressor. These variable-pitch vanes are carried by the stator of the turbomachine and are adjustable in position about their axis to optimize the flow of gas in the engine of the turbomachine. Thus, the variation of the setting of the blades makes it possible to increase the performances and to improve the efficiency of the engine of a turbomachine during all the phases of its operation, from the take-off to the landing.

This variable setting also makes it possible to vary the speed of the propeller or the blower to obtain the desired thrust, without modifying that of the turbine, which is generally calibrated at its maximum continuous speed, or even, during landing, to reverse this thrust thus replacing conventional heavy and complex reverse thrust systems.

Propeller or fan pitch control devices are hydraulic actuators (jacks driving each of the blade roots) which provide the force necessary to orient the blades in the desired position. Such a control device is for example described in the document FR2928979 .

Each variable-pitch blade has a cylindrical pivot at each of its ends, these pivots defining the axis of rotation of the blade.

The radially outer pivot of the blade is engaged in a chimney cylindrical outer annular casing which is connected by means of a rod to a control ring mounted around the annular housing. The control ring is connected by a lever to a control shaft actuated by a hydraulic cylinder. In general, the control shaft extends parallel to the axis of the housing and can be connected to one or more rings so as to control one or more stages of blades with a single cylinder.

The hydraulic cylinder rod is connected to the control shaft by a radial arm integral with the control shaft causing, by linear displacement of the cylinder rod, the rotation of each of the rings around the housing. The rotation of a control ring is transmitted by the corresponding billets to the outer pivots of the blades of a stage rotating them about their axes.

The rod of the jack has at its end a yoke for ensuring a connection with a ball joint forming the end of the radial arm integral with the control shaft. The connection between the yoke and the ball joint is ensured by means of a screw-nut connection.

Depending on the constraints of volume and architecture of the fan, it happens that the environment close to the hydraulic cylinder offers only the volume required for the nut and its kinematics during operation of the hydraulic cylinder. This volume is therefore not sufficient to install, position, or maintain the nut correctly during assembly or disassembly of the hydraulic cylinder for example during maintenance operations.

Thus, during the handling operations of the hydraulic cylinder, the operator is in the need to dismantle different neighboring parts in order to free a space large enough for the operator to access the nut of the screw-nut connection and thus be able to handle and dismount it easily.

In this context, the invention aims to solve the problems mentioned above, by proposing a hydraulic blade pitch change device to ensure rapid assembly and / or disassembly of the device, for example during a maintenance operation, while avoiding the dismantling of other neighboring rooms.

To this end, the invention proposes a hydraulic device for changing the pitch of a helix comprising a piston rod actuated by a hydraulic fluid, said piston rod comprising at its end a clevis adapted to provide a connection for the transmission of the movements of said piston rod for a pitch change of at least one helix, said hydraulic device being characterized in that it comprises a threaded nut held in position on said yoke of said piston rod by shaped holding means by the cooperation of a metal plate secured to said threaded nut and a metal ring integral with said yoke comprising elastic means able to receive and hold said metal plate in position by clipping, said nut being able to cooperate with a threaded rod to make a connection.

Thanks to the invention, the disassembly of the hydraulic cylinder, for example during a handling operation, is achieved quickly by simply unscrewing the threaded rod to separate the hydraulic cylinder from the control shaft. Disassembly of the cylinder is achieved without disassembly of other neighboring parts despite a complex architecture does not allow access to the clamping nut of the screw-nut connection.

• ledit écrou fileté est un écrou auto-freinant ;
• ladite bague métallique est une bague à encoches ;
• lesdits moyens élastiques sont formés par des pattes élastiques comportant chacune au moins une encoche ;
• ladite platine métallique comporte des protubérances aptes à coopérer avec lesdites encoches desdites pattes élastiques par clipsage ou par agrafage ;
• ledit dispositif comporte des moyens pour bloquer la rotation de ladite bague à encoches par rapport à ladite chape ;
• ledit écrou fileté comporte deux pattes faisant saillies radialement par rapport à l'axe de rotation dudit écrou fileté aptes à coopérer avec deux ouvertures agencées dans ladite platine métallique ;
• ledit sous-ensemble formé par ladite platine métallique et par ledit écrou fileté comporte des moyens pour bloquer la rotation dudit sous-ensemble par rapport à ladite bague à encoches ;
• ledit dispositif hydraulique est apte au changement de pas d'aubes à calage variable de soufflante de turbomachine.

The hydraulic propeller pitch change device according to the invention may also have one or more of the features below, considered individually or in any technically possible combination.

• said threaded nut is a self-braking nut;
• said metal ring is a ring with notches;
• said elastic means are formed by resilient tabs each having at least one notch;
• said metal plate has protuberances adapted to cooperate with said notches of said elastic tabs by clipping or stapling;
• said device comprises means for blocking the rotation of said notched ring with respect to said yoke;
• said threaded nut comprises two tabs projecting radially with respect to the axis of rotation of said threaded nut adapted to cooperate with two openings arranged in said metal plate;
• said subassembly formed by said metal plate and said threaded nut comprises means for locking the rotation of said subassembly with respect to said notched ring;
• said hydraulic device is adapted to changing the pitch of variable-speed turbine engine fan blades.

The invention also relates to a propeller pitch change control device comprising a hydraulic step change device according to the invention.

• la figure 1 est une vue en perspective d'une tige d'un dispositif hydraulique de changement de pas d'aubes à calage variable selon un premier exemple de réalisation de l'invention ;
• la figure 2 est une vue en perspective de la tige de piston illustrée à la figure 1 solidarisée à un arbre de commande d'un dispositif de commande ;
• la figure 3 est une vue éclatée d'un écrou prisonnier solidarisée sur la tige de piston illustrée à la figure 1 :
• la figure 4 est une vue en perspective d'une tige de piston d'un dispositif hydraulique de changement de pas d'aubes à calage variable selon un deuxième exemple de réalisation.

Other features and advantages of the invention will emerge more clearly from the description which is given below, by way of indication and in no way limitative, with reference to the appended figures, among which:

• the figure 1 is a perspective view of a rod of a hydraulic variable pitch pitch changing device according to a first embodiment of the invention;
• the figure 2 is a perspective view of the piston rod illustrated in FIG. figure 1 secured to a control shaft of a control device;
• the figure 3 is an exploded view of a prisoner nut secured to the piston rod shown in the figure 1 :
• the figure 4 is a perspective view of a piston rod of a hydraulic variable pitch pitch change device according to a second embodiment.

In all the figures, the common elements bear the same reference numbers unless otherwise specified.

The figure 1 is a perspective view of a piston rod of a hydraulic variable pitch pitch changing device according to a first embodiment of the invention.

In known manner, the hydraulic jack 100 is formed by a body 10 and a piston rod 20 actuated by the pressure of a hydraulic fluid circulating inside the body 10 of the jack 100.

The piston rod 20 comprises at its free end a substantially U-shaped yoke 30 which is intended to be connected to the control shaft via a radial arm secured to the control shaft causing, by linear displacement of the rod 20 of the cylinder, the indirect rotation of the blades of the blowers.

The yoke 30 comprises two coaxial orifices 32 crossing on either side the branches of the U of the yoke 30. The space 33 formed between the two branches of the U is intended to receive the end of a radial arm 50 of the yoke. control shaft, called a ball joint, as shown in FIG. figure 2 .

On the outer face of the upper branch of the U illustrated at figure 1 , the yoke 30 comprises a threaded nut 41 held in position by holding means 40. The threaded nut is adapted to cooperate with a threaded rod (not shown) inserted through the orifice 32 of the lower branch of the U. Preferably, the threaded nut 41 is a self-locking nut.

• une platine métallique 42 formée à partir d'une tôle métallique et rendu solidaire à l'écrou fileté 41 par pliage ;
• une bague métallique 43 comportant des moyens élastiques 44 aptes à maintenir en position la platine métallique 42 par agrafage ou par clipsage.

The holding means 40 are formed by:

• a metal plate 42 formed from a metal sheet and secured to the threaded nut 41 by folding;
• a metal ring 43 comprising elastic means 44 able to hold the metal plate 42 in position by stapling or clipping.

As illustrated in figure 3 , the metal ring 43 has a substantially perpendicular base 47 having an orifice adapted to receive a crimping ring 46. The elastic means 44 are arranged in projections relative to the base 47, and at the edge thereof, forming elastic tabs in which notches 48 are arranged to perform a clipping or stapling function.

The metal ring 43 is secured to the U-shaped yoke for example by shrinking the crimping ring 46 in the hole 32 of the upper branch of the U of the yoke 30.

According to the first embodiment of the invention illustrated in figure 1 , the yoke comprises a face 34 serving as a support for the metal ring 43 is thus performing a function of anti-rotation of the metal ring 43. This bearing surface 34 is obtained by making a flat on the yoke 30 adapted to form a flat support for the metal ring 43.

The metal plate 42 is formed from a flat metal sheet of substantially rectangular shape having two openings, for example of rectangular shape and arranged in parallel manner.

The nut 41 comprises a threaded upper part and a base on which two tabs 45 project radially with respect to the axis of rotation of the nut 41, the shape of the tabs 45 being complementary to the shape of the openings of the metal plate. 42.

The metal plate 42 is made integral with the nut 41 by folding the lateral edges of the metal sheet on either side of the nut and so that the tabs 45 protruding through the two openings of the metal plate 42. Thus, the metal plate 42 is integral with movements of the threaded nut 41.

The metal plate 42 also comprises protuberances 49 able to cooperate with the elastic tabs 44 of the metal ring and more precisely with the notches 48 of the elastic tabs 44.

Thus, the subassembly formed by the nut 41 and the plate 42 is inserted into the metal ring 43, integral with the yoke, until the introduction of the protuberances of the metal plate 42 in the notches 48 of the elastic tabs 44 .

The protuberances 49 of the metal plate 42 and the corresponding notches 48 may be of different sizes and shapes from the moment they perform a clipping or stapling function between the plate 42 and the ring 43.

Of course, the platen-nut subassembly can be detached from the metal ring 43, and more particularly from the elastic tabs 44, by means of a specific tool allowing the elastic tabs 44 to be sufficiently spaced apart to disengage the protuberances 49 from the notches. 48.

Thus, the nut 41 is made captive, held in position on the yoke 30 while ensuring a certain clearance of operation between the subassembly and the metal ring 43. The operating clearance thus allows the nut 41 to be precisely positioned. by self-centering, depending on the position of the threaded rod and thus be able to perform the screwing function between the nut and the threaded rod. Indeed, the threaded rod is a calibrated rod which eliminates the play in the orifices 32 of the yoke 30.

For this purpose, the orifice 32 of the lower branch of the U comprises a ring 31 whose diameter is also calibrated to receive the calibrated threaded rod (not shown).

An additional function of anti-rotation is provided between the platen-nut subassembly and the metal ring 43 by positioning between two elastic tabs 44 of the metal ring 43, the tabs 45 projections. Thus the rotation of the platen-nut sub-assembly is blocked on the one hand by the elastic means and on the other by the spacing of the elastic tabs 44 allowing the passage of the tabs 45 projecting and forming lateral stops.

The figure 4 is a perspective view of a piston rod of a hydraulic variable pitch pitch change device according to a second embodiment.

In this second embodiment, the anti-rotation function of the metal ring 143 relative to the yoke 30 is achieved by the particular geometry of the metal ring 143.

For this purpose, the metal ring 143 has an outgrowth of material at its base 147 so as to protrude from the bearing face of the yoke 30. At the level of this protrusion of material, the metal ring 143 has a protrusion 150 protruding and directed towards the inside of the yoke 30 adapted to block any displacement by rotation of the metal ring 143 relative to the yoke 30.

The invention has been mainly described for a hydraulic device for changing the pitch of blades with variable turbine engine fan timing; however, the invention is also applicable to any system with propellers such as wind turbines, industrial fans or turbojets.

• réduction des coûts de réalisation ;
• réduction du temps de réalisation ;
• simplification de la gamme de fabrication ;
• réduction des coûts des outillages ;
• réduction des coûts matière.

Other advantages of the invention include the following:

• reduction of implementation costs;
• reduction of the production time;
• simplification of the manufacturing range;
• reduction of tooling costs;
• material cost reduction.

Claims (10)

1. Hydraulic device (100) for changing a propeller pitch comprising a piston rod (20) actuated by a hydraulic fluid, said piston rod (20) comprising a clevis (30) at its end to form a connection for the transmission of movements of said piston rod (20) in order to change the pitch of at least one propeller, said hydraulic device being characterised in that it comprises a threaded nut (41) held in position on said clevis (30) of said piston rod (20) by retaining means (40) formed by the cooperation of a metal plate (42) fixed to said threaded nut (41) and a metal ring (43) fixed to said clevis (30) comprising elastic means (44) that can hold and retain said metallic plate (42) in place by clip fitting, said threated nut (41) being designed to cooperate with a threaded rod to make a connection.
2. Hydraulic device (100) for changing a propeller pitch according to claim 1, characterised in that said threaded nut (41) is a self-locking nut.
3. Hydraulic device (100) for changing a propeller pitch according to either claim 1 or 2, characterised in that the metal ring (43) is a notched ring (48).
4. Hydraulic device (100) for changing a propeller pitch according to one of claims 1 to 3, characterised in that said elastic means are formed from elastic tabs (44) each comprising a notch (48).
5. Hydraulic device (100) for changing a propeller pitch according to claim 4, characterised in that said metallic plate (42) comprises protuberances (49) capable of cooperating with said notches (48) of said elastic tabs (44) by clip fitting.
6. Hydraulic device (100) for changing a propeller pitch according to one of claims 1 to 5, characterised in that it comprises means (34,150) for blocking the rotation of said notched ring (43) relative to said clevis (30).
7. Hydraulic device (100) for changing a propeller pitch according to one of claims 1 to 6, characterised in that said threaded nut (41) comprises two tabs (45) projecting radially from the rotation centre-line of said threaded nut (41) and capable of cooperating with two openings formed in said metal plate (42).
8. Hydraulic device (100) for changing a propeller pitch according to one of claims 1 to 7, characterised in that the sub-assembly formed by said metallic plate (42) and by said threaded nut (41) comprises means (45) for blocking rotation of said sub-assembly relative to said notched ring (43).
9. Hydraulic device (100) for changing a propeller pitch according to one of claims 1 to 8, characterised in that said hydraulic device (100) is capable of changing the pitch of variable-pitch blades in a turbomachine fan.
10. Control device for changing a propeller pitch, characterised in that it comprises a hydraulic device (100) according to one of claims 1 to 9.

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