EP0272176A1 - Hydraulic rotary vane actuator, especially for aircraft rudder control - Google Patents

Abstract

Rotary hydraulic actuator, comprising a pallet (1) rotatably and sealingly mounted in a chamber (2) formed in a body (3) and on the faces of which a hydraulic fluid pressure is applied, the pallet being mechanically integral with an element to be driven in rotation; the pallet (1) comprises two parts (4, 5) extending radially on either side of its axis of rotation (XX), and these two parts are each movable in a chamber (8, 9) extending over an angular sector less than a half-circumference, this chamber being divided by said part (4, 5) into two compartments; the actuator comprises a hydraulic circuit for supplying the chambers (8, 9) produced so as to be able to drive the pallet (1) in rotation in one direction or the other. This arrangement reduces the bulk and increases the reliability of the actuator.

Description

The present invention relates to a rotary hydraulic actuator, intended for driving in rotation an element such as an aircraft control surface. However, this application is not limiting, this actuator being capable of being used for driving very diverse elements.

The actuator targeted by the invention is of the type comprising a paddle rotatably and sealingly mounted in a chamber provided in a body, and on the faces of which a hydraulic fluid pressure is applied, the paddle being mechanically integral with the element to be driven in rotation.

According to the invention, the pallet comprises at least two parts extending radially on either side of its axis of rotation, and these two parts are each movable in a chamber extending over an angular sector less than a half circumference, this chamber being divided by said part into two compartments, and the actuator is provided with a hydraulic circuit for supplying the chambers with fluid produced so as to be able to drive the pallet in rotation in one direction or the other.

Thus, when the hydraulic pressure applied to two opposite faces of the pallet is greater than the pressure applied to the other two faces, the pallet rotates and drives the element integral with its axis in rotation.

This solution is advantageous for ensuring the direct rotation drive of a shaft or a pivot as soon as this rotation is less than one turn, as is the case in particular for an aircraft control surface (helicopter planes).

Indeed, compared to ac devices commonly known, its size is considerably reduced, all intermediate parts such as links articulated between the element to be driven and its control member being eliminated.

Correspondingly, the invention provides better reliability than known systems.

According to one embodiment of the actuator, the pallet comprises four radial parts also angularly spaced and rotatable in four respective chambers, in each of which open an inlet pipe and an outlet pipe for the hydraulic fluid.

According to another particular feature of the invention, the hydraulic circuit comprises supply lines arranged in the body as well as in a central hub of the pallet.

In one embodiment of the actuator, the hub is axially traversed by a shaft of a rotary distributor on the periphery of which grooves for the passage of hydraulic fluid are formed, and this shaft is suitable for simultaneously closing the supply lines and return of the fluid when the distributor is in equilibrium position relative to the pallet, while the rotation of this shaft by a determined angle puts the pipes of the body and the hub of the pallet into communication, which causes a correlative rotation of the pallet with servo-control of the latter's position to the new angular position of the shaft.

• - la Figure 1 est une vue en coupe trans­versale d'un premier mode de réalisation de l'ac­tionneur hydraulique rotatif selon l'invention;
• - la Figure 2 est une vue en coupe trans­versale analogue à la Figure 1 d'un second mode de réalisation de l'actionneur selon l'invention;
• - la Figure 3 est une vue en coupe trans­versale simplifiée d'un troisième mode de réalisation de l'actionneur selon l'invention;
• - les Figures 4A et 4B sont des vues en cou­pe longitudinale et élévation partielle de l'action­neur suivant 4A-4A et 4B-4B de la Figure 3;
• - les Figures 5A et 5B sont des vues sché­matiques correspondant à la Figure 3 et montrant la distribution des pressions hydrauliques lorsque la palette est entraînée dans le sens horaire (Figure 5A) ou dans le sens anti-horaire (Figure 5B);
• - la Figure 6 est une vue en coupe longitu­dinale et élévation partielle d'un mode de réalisation industrielle de l'actionneur selon l'invention;
• - la Figure 7 est une vue en coupe trans­versale suivant 7-7 de la Figure 6;
• - la Figure 8 est une vue en élévation en bout de l'actionneur des Figures 6 et 7;
• - la Figure 9 est une vue en perspective partielle de l'actionneur des Figures 6 à 8 montrant un corps enveloppant la palette rotative et les con­nexions du circuit hydraulique;
• - la Figure 10 est une vue en coupe trans­versale et élévation partielle analogue à la Figure 6 illustrant la mise en oeuvre de l'actionneur à la commande d'un potentiomètre électrique;
• - la Figure 11 est une vue en élévation longitudinale schématique illustrant la mise en oeuvre de plusieurs actionneurs en série coaxialement à un même arbre;
• - la Figure 12 est une vue en coupe trans­versale suivant 12-12 de la Figure 11 d'un des ac­tionneurs.
• - la Figure 13 est une vue de dessus d'une variante de réalisation d'une palette d'un actionneur selon l'invention;
• - la Figure 14 est une vue en coupe suivant 14-14 de la palette de la Figure 13;
• - la Figure 15 est une section suivant 15-15 de la Figure 14.

Other features and advantages of the invention will appear during the description which follows, made with reference to the accompanying drawings which illustrate several embodiments thereof. title of nonlimiting examples:

• - Figure 1 is a cross-sectional view of a first embodiment of the rotary hydraulic actuator according to the invention;
• - Figure 2 is a cross-sectional view similar to Figure 1 of a second embodiment of the actuator according to the invention;
• - Figure 3 is a simplified cross-sectional view of a third embodiment of the actuator according to the invention;
• - Figures 4A and 4B are views in longitudinal section and partial elevation of the actuator along 4A-4A and 4B-4B of Figure 3;
• - Figures 5A and 5B are schematic views corresponding to Figure 3 and showing the distribution of hydraulic pressures when the pallet is driven clockwise (Figure 5A) or counterclockwise (Figure 5B);
• - Figure 6 is a longitudinal sectional view and partial elevation of an industrial embodiment of the actuator according to the invention;
• - Figure 7 is a cross-sectional view along 7-7 of Figure 6;
• - Figure 8 is an end elevational view of the actuator of Figures 6 and 7;
• - Figure 9 is a partial perspective view of the actuator of Figures 6 to 8 showing a body enveloping the rotary vane and the connections of the hydraulic circuit;
• - Figure 10 is a cross-sectional view and partial elevation similar to Figure 6 illustrating the implementation of the actuator when controlling an electric potentiometer;
• - Figure 11 is an elevational view schematic longitudinal illustrating the implementation of several actuators in series coaxially with the same shaft;
• - Figure 12 is a cross-sectional view along 12-12 of Figure 11 of one of the actuators.
• - Figure 13 is a top view of an alternative embodiment of a pallet of an actuator according to the invention;
• - Figure 14 is a sectional view along 14-14 of the pallet of Figure 13;
• - Figure 15 is a section along 15-15 of Figure 14.

The hydraulic actuator presented in Figure 1 comprises a pallet 1 rotatably mounted around an axis X-X in a chamber 2 formed in a body 3 and on the faces of which can be applied a hydraulic fluid pressure.

The pallet 1 comprises two parts 4, 5 extending radially on either side of the axis of rotation XX as well as a cylindrical central hub 6, integrally formed with the two radial parts 4, 5. The hub 6 is in leaktight contact with two radial projections 3a, 3b of the body 3, in which two seals 7 are received.

The hub 6 and the projections 3a, 3b divide the chamber 2 into two compartments 8, 9 whose cylindrical walls 8a, 9a extend over at least half a circumference and are in sealed contact with the ends of the radial parts 4 , 5 thanks to seals 11, 12 received in grooves formed at the ends of said parts 4, 5.

The hydraulic circuit of this actuator includes two pairs of similar pipes which supply the hydraulic compartments 8, 9: an inlet A opens on the one hand into a pipe 13 formed in the body 3 which opens into the chamber 9, and on the other hand into a bypass 14 external to the body 3 and which extends by a pipe 15 in the body 3. The pipe 15 is diametrically opposite to the pipe 13 and opens into the chamber 8, on the side opposite to the pipe 13.

In addition, a fluid outlet B communicates on the one hand with a pipe 16 which opens into the chamber 8 on the side of the radial part 4 opposite to that where the pipe 15 opens, and on the other hand with a bypass 17 external to the body 3. This branch 17 is extended by a pipe 18 in the body 3, diametrically opposite to the pipe 16 and which opens into the part of the compartment 9 opposite to that which receives the pipe 13.

If a hydraulic fluid at pressure P1 is introduced through the inlet A, this fluid travels in the pipes 13, 14, 15 the path indicated by the arrows to supply the compartments 9 and 8 respectively, and more precisely the sub-compartments included between the pallet 1 and the walls of the body 3 in which the conduits 13, 15 are drilled. Therefore, the pallet 1 rotates around the axis XX in the direction of the arrow in solid lines (clockwise), while the fluid at pressure P0 is expelled from the two sub-compartments opposite the two sub-compartments which receive the pressure P1, to return to the reservoir via the pipes 16, 17 and 18.

If conversely, the pressure P1 greater than P0 is applied to input B, the pallet 1 rotates in the opposite direction to the previous one, and the fluid returns to the reservoir via the pipes 13, 14 and 15, as indicated by the dotted arrows.

The pallet 1 is secured by its hub 6 with the element to be driven in rotation, not shown, and which can for example be an aircraft control surface.

In the second embodiment illustrated in Figure 2, the pallet 21 comprises four radial parts 22, 23, 24, 25 also spaced angularly, as well as a central hub 26 made integrally with the parts 22-25. The hub 26 is in sealed contact with the ends of four radial extensions 27, 28, 29, 31 of the body 32 thanks to four seals 33. These four extensions 27-31 delimit between them four chambers 34, 35, 36, 37 with cylindrical outer walls 34a, 35a, 36a, 37a in leaktight contact with the ends of the radial parts 22-25 by means of seals 30 received in the ends of said radial parts 22-25.

The hydraulic supply circuit of this actuator is constituted as follows: a fluid inlet Aʹ feeds an annular pipe 38 external to the body 32 and which communicates with four radial pipes 39, 41, 42, 43 passing through the body 32 and which open into the respective compartments 37, 36, 35, 34 facing the corresponding faces of the four radial parts 25, 24, 23, 22. In addition, a fluid outlet Bʹ communicates with a peripheral pipe 44 external to the body 32 and which feeds four radial pipes 45 , 46, 47, 48 passing through the body 32 and emerging into the com respective compartments 37, 34, 35, 36 on the side of the radial parts 25, 22, 23, 24 opposite the pipes 39, 43, 42, 41.

If a hydraulic pressure P1 is applied to the inlet Aʹ, the fluid travels the path indicated by the arrows in solid lines and exerts on the radial parts 25, 22, 23, 24 of the pallet 21 the pressure P1 which rotates the pallet clockwise. Correlatively the fluid at the pressure P0, from the chambers 34-37 through the conduits 45-48 and the pipe 44 to the outlet Bʹ towards the reservoir. Of course, the pallet 21 rotates in the opposite direction to the previous one if the pressure P1 is applied at Bʹ, while the outlet Aʹ is at the pressure P0.

A third embodiment of the actuator will now be described with reference to Figures 3, 4A, 4B, 5A and 5B.

The pallet 51 is here constituted by two radial parts 52, 53, diametrically opposite and integrally formed with a cylindrical central hub 54. The parts 52-53 can be angularly struggled around the axis XX of the hub 54 in chambers 55, 56 formed in a body 57. The seal between the two compartments of each chamber 55, 56 is obtained by seals sealing 58 received in grooves at the ends of the radial parts 52, 53, while sealing between the hub 54 and the body 57 is obtained by seals 59 housed in diametrically opposite grooves in the body 57.

The hydraulic circuit here comprises, machined in the hub 54, return pipes 61 to the pressure of the reservoir R, the ends of which, diametrically opposite, open opposite two gor transverse ges 62 formed on the periphery of a central shaft 63 received in an axial bore of the hub 54. In the latter, four radial conduits 64, 65, 66, 67 are further provided. The conduits 64, 65 open into two compartments opposite of the chamber 55, separated by the radial part 52, while the conduits 66, 67 open into the two compartments of the chamber 55 separated by the radial part 53. The grooves 62 are machined in a portion 63a of cylindrical section of the tree 63. This portion 63a defines the distribution characteristics of the system.

Between on the one hand the conduits 64 and 65 and on the other hand the conduits 66 and 67 are formed internally at the hub 54, two supply conduits 68 for the hydraulic fluid at pressure P, supplied by a hydraulic source not shown.

The operation of the actuator of Figures 3 and 4A-4B is explained in Figures 5A and 5B. At rest, the actuator is in the position of Figure 3, where we see that the conduits 61 and 68 are closed by the rounded tops of the central portion 63a of the shaft 63, so that no fluid circulates in the actuator.

If the shaft 63 is rotated by a determined angle clockwise (FIG. 5A), the portion 63a of the shaft 63 discovers the supply conduits 68, which then communicate with the respective conduits 65 and 67 The fluid at pressure P therefore fills the compartments of the chambers 55, 56, which makes the pallet 51 rotate clockwise, while the fluid at pressure R flows from the two other compartments of the chambers 55, 56 by the conduits 64, 66, 61 to the tank at pressure R.

The circuit followed by the hydraulic fluid, the pressure exerted by it and the rotation of the pallet 51 are symbolized by the arrows carried in FIG. 5A.

The rotation of the pallet 51 continues until the conduits 68 and 61 are again closed by the portion 63a of the shaft 63, the pallet 51 then having "copied" the new angular position of the latter and s' immobilizing.

If the shaft 63 is rotated counterclockwise (FIG. 5B), this rotation connects the conduits 68 and 64, 66, so that the fluid rotates the pallet 51 also in the counterclockwise direction, and exits at the pressure R through the conduits 65 and 67. As previously, the rotation of the pallet 51 stops when the conduits 61 and 68 are again closed by the portion 63a, the position of which has been "copied" by the pallet 51.

In this application, the actuator therefore functions as a device for copying the angular position of a control shaft.

In the embodiment illustrated in Figures 6 to 9, the actuator 65 is equipped with a pallet 66 comprising two radial parts 70 diametrically opposite and joined by an annular part 69 and a hub 71 of annular section axially passing through the annular part 69 The latter is secured in rotation with the hub 71 by complementary axial splines such as 72. Likewise, to ensure the drive in rotation of the shaft 73, housed in the axial recess of the hub 71 and secured to an element not shown, any suitable means is provided, such as complementary axial splines 90, formed on the periphery of the shaft 73 and in the internal wall of the hub 71. On the side opposite the shaft 73, a bolt 130 provided with a thread 190 is screwed into a thread of the hub 71, coaxially with the shaft 73, and makes it possible to tighten the bearings 92, 93.

The actuator 65 also comprises an annular body 74 surrounding the radial parts 70 and the central part 69, and on the periphery of which are machined two circumferential grooves 75, 76 coaxial with the general axis Y-Y of the actuator. The groove 75 communicates on the one hand with a supply duct 77, 78 formed in an outer casing 79 and a sleeve 80, and on the other hand with two radial ducts 81 drilled in the body 74 and opening into respective chambers 82 , 83. Similarly, the groove 76 communicates on the one hand with a supply duct 84, arranged in the casing 79 and which opens into a bore 130 of a second sleeve 87, and on the other hand with two ducts radials 86 of the body 74, which open into the other two hydraulic chambers 88, 89. The body 74 is provided with an annular seal 74a housed in a groove in the body formed between the grooves 75, 76.

The chambers 82, 83 and 88, 89 are delimited by the body 74 and by the radial parts 70 as well as by the central part 69. The latter as well as the radial parts 70 are mounted in leaktight manner with respect to the body 74 by seals 91, 120 received in respective grooves of the body 74 and of the ends of the radial parts 70.

The actuator 65 is also equipped with two ball bearing bearings 92, interposed between the hub 71 and an annular body 94 contained in the casing 79. The latter is provided with two radial flanges 97, 98 interposed between the radial parts 70 and bearings 92, which are complementary tightly held in place axially by an end flange 99 of the hub 71. The assembly is closed, on the side opposite to the flange 99, by a cover 101 held by fixing screws 102 engaged in the casing 94.

When the hydraulic fluid under supply pressure enters the conduits 78, 77 and the groove 75, this fluid reaches the two opposite chambers 82, 83 through the radial bores 81, and causes the pallet 66 to rotate clockwise. The fluid returns to the reservoir from the chambers 88, 89 through the conduits 86, the groove 76, the pipe 84 and the sleeve 87. This rotational movement is reversed if the hydraulic pressure is conveyed through the groove 76.

Figure 10 shows an actuator 100 identical to the actuator 65, except that its cover 101 is replaced by a flange 103 which receives the end 104 of an electric potentiometer 105 of shaft 73. This potentiometer 105 is provided with a slider 106 driven in rotation in a manner known per se by the shaft 73 on the resistance of the potentiometer, when this shaft is itself rotated as described above with reference to FIGS. 6 to 9.

As a variant, it is possible to associate with the shaft 73 of the actuator 65, 100, an element for detecting any rotary position, the potentiometer 105 being given only by way of example. Such an arrangement allows these elements to be inserted into an electro-hydraulic servo loop.

Figures 11 and 12 show a series assembly of several coaxial actuators 107, each pallet 109 of which is provided with a male 124-female coupling 125, the male elements 124 fitting into the female elements 125. Each action neur 107 is of the type of that of FIG. 1 and its pallet 109 therefore comprises, in addition to the coupling 124-125, two radial parts 111 connected by a central hub 112 and which can be angularly struggled in two chambers 113 fed by bores 114, 115, 116, 117 formed in the body 118.

Each actuator 107 having its own hydraulic circuit, the series assembly of several coaxial actuators 107 makes it possible, in the case of actuation of an aircraft control surface, to provide the redundancy required for safety reasons.

In all of the embodiments described, the chambers or compartments (8,9; 55, 56; 83-88, 82; 113) extend over angular sectors less than half a circumference.

The pallet 130 of Figures 13 to 15 is provided, on the two opposite faces of its hub 131 with two sealing rings 132 connected by sealing cords 133, 134 extending in the extensions of a diameter of the rings 132 The rings and the cords 133, 134 are housed in corresponding grooves 135, 136 formed in the opposite faces of the hub 131 and in the radial parts 137, 138 of the pallet 130. The cords 133, 134 extend from one side and on the other side of the hub 131 in a plane containing a diameter of the rings 132. The latter and the cords 133, 134 ensure an excellent seal between the pallet 130 and the wall of the chamber of the actuator.

Claims (10)

1 - Rotary hydraulic actuator device, comprising a pallet (1, 21, 51, ...) rotatably and sealingly mounted in a chamber (2; 34, 35, ...) formed in a body (3, 32, 74, ....) and on the faces of which a hydraulic fluid pressure can be applied, the pallet being mechanically integral with an element to be driven in rotation, characterized in that the pallet (1, 21, 51 ,. ..) has at least two parts (4, 5) extending radially on either side of its axis of rotation (XX), and these two parts are each movable in a chamber (8, 9; 55, 56 , ...) extending over an angular sector less than a half-circumference, this chamber being divided by said part (4, 5; 52, 53; 67, 68) into two compartments, and in that it is provided with a hydraulic circuit for supplying the chambers (8, 9; 55, 56) with fluid produced so as to be able to drive the pallet (1, 21, 51, 66) in rotation in one direction or the other. 2 - actuator device according to claim 1, characterized in that the pallet (21) comprises four radial parts (22, 23, 24, 25) also angularly spaced and rotatable in four respective chambers (34, 35, 36, 37), into each of which open an inlet pipe (43, 42, ...) and an outlet pipe (46, 47, ...) of the hydraulic fluid. 3 - actuator device according to one of claims 1 and 2, characterized in that the hydraulic circuit comprises pipes (13, 15, ...; 39, 43, 42, ...) formed in the body (3, 32) and opening into the compartments of each room (8, 9; 34-37). 4 - actuator device according to one of claims 1 and 2, characterized in that the hydraulic circuit comprises supply lines (68) and return (61) formed in a central hub (54) of the pallet (51) (Figure 3). 5 - actuator device according to claim 4, characterized in that the hub (54) is crossed axially by a shaft (63) of a rotary distributor on the periphery of which are formed grooves (62) for passage of the hydraulic fluid, and this shaft (63) is adapted to simultaneously seal the supply lines (68) and return (61) of the fluid when the distributor is in equilibrium position relative to the pallet (51), while the rotation of this shaft of a determined angle communicates the supply (68) and return (61) lines of the body (54) with those (64, 66 or 65, 67) of the hub of the pallet (51), which causes a correlative rotation of the pallet with servo-control of the position of the latter to the new angular position of the shaft (63). 6 - actuator device according to one of claims 1 and 3, characterized in that the pallet (66) comprises two radial parts (70) diametrically opposed, joined by a central part (69) which receives a hub (71) integral with said radial parts in rotation and in which is formed an axial recess receiving a shaft (73) integral with the element to be driven and the hub (71), the ends of the radial parts (70) and the hub (71) being in sliding contact watertight with the body (74), which surrounds the pallet (66) and has on its periphery two circumferential grooves (75, 76) communicating, each, on the one hand with conduits (77, 78, 84) of passage of the hydraulic fluid drilled in an envelope (79) containing the annular body (74) and the pallet (66), and on the other hand with respective radial entry holes (81, 82) in the chambers (82, 88 ) and outlet (86, 87) thereof, formed in the annular body (74) (Figure 6-8). 7 - actuator device according to claim 6, characterized in that it is equipped with rolling bearings (92) interposed between the hub (71) of the pallet (66) and the casing (79), mounted in leaktight manner the hydraulic fluid chambers. 8 - actuator device according to claims 6 and 7, characterized in that the pallet (66) and its hub (71) are secured in rotation by complementary axial grooves (72), as well as the shaft (73) and the hub (71). 9 - Device according to one of claims 1 to 8, characterized in that it comprises a series of actuators (107) whose vanes (109) are each provided with a male coupling (124) -female (125) nested one inside the other, each actuator having its own hydraulic circuit. 10 - Device according to claim 1, characterized in that the pallet (130) comprises two sealing rings (132) circular on its two opposite faces and sealing beads (133, 134) housed in respectively circular grooves of faces of the hub (131) and formed radially around the radial parts (137, 138) of the pallet, in a plane containing a diameter of the rings (132).

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