FR3019146A1 - COMBINATION TRAY FOR HELICOPTER ROTOR - Google Patents

Abstract

The so-called "helicopter rotor combiner platter" greatly simplifies traditional flight controls. An intermediate plate (1) is coupled with the swashplate (2) which, movable on its sphere, controls the cyclic pitch of the blades. The sliding of this assembly on the mast sleeve (5) makes it possible to modify at the same angle the inclination of all the blades, it is the collective pitch. The actions of the pilot on the commands transmit the orders via cables directly for the cyclic pitch, or via a fork (7) for the collective pitch. The device adapts without expensive studies to the current helicopters of all types that it alleviates, without modification of the usual controls, a hydraulic assistance is possible for the heavy helicopters.

Description

TECHNICAL FIELD The described device makes it possible to simplify the flight controls of the rotorcraft and more particularly the helicopters by modifying the places and the means of action on the kinematics of the main rotor, in particular on the swashplate. The device thus described is named "helicopter rotor combiner plate". STATE OF THE PRIOR ART On all the helicopters, the flight controls are implemented by three different levers: the cyclic pitch stick, the collective pitch and the rudder, operated with both feet, this last command is cited for memory and is not part of the described device.

Figure 1 is a diagram of these conventional commands. Cyclic and collective pitch controls are associated at the level of a complex device known as the combiner. All these conventionally used control means transmit the movements of the pilot to the swashplate which operates the cyclic and collective variations of blade pitch via the usual pitch rods found on all the rotors. The swashplate is articulated on a sphere that slides on the sheath of the rotor mast. This sphere is translated in translation by the cyclic plateau, this detail must be underlined for a better understanding of the sequence. The translation movements of the swashplate are caused by the action of the pilot who, by means of the collective handle, modifies the position of the combiner to cause the simultaneous displacement of all the connecting rods which leave the combiner to the swashplate, the pilot thus modifies of the same value the inclination of all the blades is the collective variation of the pitch. The tilts of the swashplate are caused by the action of the pilot who, by means of the cyclic stick, modifies the position of the swashplate by the independent movement of each connecting rod, the inclination of the swashplate modifies the inclination of the blades during the rotation of the rotor is the cyclic variation of the pitch.

In order to transmit the pilot's orders, the usual and universally used devices on the helicopters use flight controls based on connecting rods, corner returns and links that arrive and depart from the central element, the combiner. These rods are equipped with screw settings, they are heavy and their joints are game seats that generate blur in the controls. Their installation requires a large number of welded parts on the chassis of the helicopter, welds which must be precise, often machined in place and which are as many appendices to check during maintenance visits. All these many articulated parts must have functional games as reduced as possible, requiring great machining precision in order to avoid the "stacking" of games at the end of the chain, so inaccuracies on the movements of the fmal object : the swashplate. These sets of connecting rods and crossovers are delicate and difficult to adjust. During maintenance visits, these adjustments require very important dismantling at the level of the cell and the compartment of the rotor mast, the setting up of pins and shims (from six to eight, plus the six pins of positioning of the swashplate) , as many minute operations that take time and immobilize the helicopter, moreover, these adjustment procedures have a significant cost. Apart from the light and ultra-light helicopters, the controls receive a hydraulic assistance called servo-command, which is usually at the end of the mechanical chain previously described, it is understood that any excessive play in these mechanical chains will affect the smooth operation servo-commands, the worst being to arrive at self sustained low frequency phenomena known as "pumping", which can be added to the phenomena induced by the periodic oscillations due to the rotor itself, to the frequency of the rear beam etc. In addition, when the helicopter is in flight, it is suspended from the main gearbox known as BTP (24), by bars that provide some mobility of the BTP (24) relative to the cell. The BTP (24) is damped at its junction with the cell so as to better filter the vibrations generated by the rotor. The traditional controls are largely supported by the cell and the final part, which includes the servocontrols, is in solidarity with the BTP (24). These different vibratory regimes between the "cell" part and the BTP part (24), can cause micro displacements at the level of the servo-commands, which thus risk to induce periodic variations, even of small amplitude, either at the level of the rotor , either at the level of commands, so felt by the pilot. All these vibratory phenomena, as well as those not mentioned here, are felt by the pilot and make his work uncomfortable. DISCLOSURE OF THE INVENTION The device according to the invention makes it possible, without changing the usual control commands, to considerably simplify the flight controls by removing the connecting rods, links, rods, which reduces the weight of the helicopter, and increases the driving comfort. To achieve this result, it is necessary to rethink the set called combiner used in all helicopters, this is the reason for this invention. The invention presented here consists in placing the equivalent of the rationalized combinator at the level of the swashplate.

FIG. 2 represents this device in its entirety, FIG. 3 is a diagram of the combinatorial plate, the text below is relative to these two figures and to the elements that compose them. Note: Unless otherwise stated, explicitly or implicitly, elements in several separate figures are assigned a single reference.

The swashplate and its inclination sphere found on all the helicopters, are assembled with the intermediate plate (1) which slides on the sheath of the rotor mast (3), the assembly thus constituted receives the name of " Helicopter rotor combiner plate ", this new swashplate is indicated by (2). In this device, it is the sphere, integrated in the intermediate plate (1), which drives the swashplate (2) contrary to what is usually done, also note that the sphere is one of the means to ensure the inclination of the cyclical plateau in all directions. To obtain these inclinations, one could as well use a cardan or any other device, which would not change the principle of the invention proposed here. In this new system, the rods, references, combinator and rods, usually used, are replaced by cables. Each cable is composed of a sheath and a core, smooth, ball or other, which slides in the sheath. The sheaths can be terminated at each end by devices to compensate for edging due to the inclinations of the controlled elements, the spherical ball-type joint is preferred (10) but other devices can fulfill this function. At the joints (10), the sheaths are provided with settings (13) to refine the position of the sheath, likewise, the souls are provided at each end of settings that can both compensate for possible deletions and to fine tune the settings (14). The sheaths are supported on the fixed parts (20, 15, 1), while the cores are controlled by the cyclic (18) and collective (19) sleeves via the rudder (22) and the conjugation shaft (23), thus allowing the displacement of the controlled elements (2, 7). Subsequently these sets will be designated by the word "cable", there are two kinds of cables, the cyclic (11) which can be three in number, and the collective (12), which can possibly be doubled in "push" -sweater". The intermediate plate (1) slides on the sheath (5) of the rotor mast (3) to allow collective pitch variation. Sliding of the intermediate plate on the rotor mast can be facilitated by the use of a self lubricating guide (6) adhered to the sleeve (5) of the rotor mast (3). This sliding is obtained by pivoting a fork (7) articulated on a support (15) belonging either to the casing of the main gearbox BTP (24) which is to be preferred, or possibly to the frame of the helicopter . This fork (7) is connected to the intermediate plate (1) by two rods (8) intended to make it possible to pivot, these two links immobilize in rotation the intermediate plate (1). The fork (7) is controlled by the cable called "collective" (12) In its "collective low" position the fork is abutting on a fixed part belonging either to its support or preferably to the BTP (24), there will have one or more stops (9), with at least one for each branch of the fork.These stops will have the advantage of being provided with settings to perfect the position of the fork to optimize the settings of zero blades or to refine The range is cited here as an example, other devices allowing both the translation of the mixing plate and its immobilization in rotation can be exploited.The movements of the core of the collective cable (12 ) are initialized by the pilot acting on the collective pitch stick (19) The intermediate plate (1) receives the three cyclic control cables (11) whose movements are initiated by the pilot acting on the stick cyclic step (18), via the cyclic lifter (22) and via the conjugation shaft (23). These cables (11) replace the rods usually used. The cables (11) allow to tilt the swashplate (2) in all directions to vary the inclination of the blades during the rotation of the rotor. A compass called fixed compass (16) immobilizes in rotation the non-rotating part of the swashplate (2) while the rotating part of this swashplate (2) is secured to the rotor mast by a usual compass (17), said rotating compass. The compass cited here is usually used on helicopters but can be replaced by any other device that performs the anti rotation functions required.

FIG. 4 illustrates these operations. The cable sheaths are secured to the intermediate plate (1) by means of the ball joints (10) or other, and adjustments (13). The lower part of the cables is left free under the intermediate plate (1), with an excess length to be defined to allow the sliding of the plate (1) on the mast sleeve (5). These sufficient free lengths imply that the cables do not cause any vibratory coupling between the cell and the BTP (24), so there are no interactions on the rotor or the controls as can occur with the systems. classics. The cables, the length of which has been accurately calculated, can therefore be better adjusted to the control systems, thus simplifying and reducing the adjustments, however, the adjustments by screws or other system which can be provided the ducts (13). ), and the souls (14), will refine the settings in position of the controls. This coupling between the swashplate and the intermediate plate makes it possible to eliminate the complex device found on all the helicopters, known as the "combiner", as well as all the connecting rods, angle references, relays and linkages of settings that came and went from this combiner (see Figure 1). The cables mentioned here can be replaced by hydraulic controls consisting of double-acting cylinders, placed at the controls and controlled components, however, the complexity of the device is related to the supply pipes (two per cylinder), and the constraints associated with any hydraulic control (purging, leaks, weight etc.). Electric cylinders can also be controlled via the cables, but this would also complicate the installation.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will become apparent on reading the following detailed description. However, the present invention is not limited to the embodiments described and shown, but the person skilled in the art will know bring any variant that fits his mind. For an understanding of the invention, reference is made to the accompanying drawings, in which: FIG. 1 is a representation of the current conventional controls, FIG. 2 is a representation of the controls by cable and combinatorial tray, FIG. 3 is a diagram of the tray. 4 is a representation of the movements of the swashplate and the swashplate, FIG. 5 represents this type of control adapted to heavy helicopters requiring hydraulic assistance.

ACHIEVEMENTS Steering can be done from the classic controls: cyclic stick, collective lever and rudder. By way of example, starting from FIG. 1, the conventional swashplate is replaced by the combiner plate formed by the assembly of the intermediate plate (1) and the swashplate (2), the fork (7) and its support (15) are integrated in the BTP (24). All the rest of the usual kinematics is removed until the crossbar (22) inverted cyclic handle (18), and the collective handle (19). It is noted that the cyclic sleeve conjugation shaft (23) can also be reversed so that the cable arrives on the intermediate plate (1) and on the swashplate (2) in the same place as the old rods.

See Figure 2. The deleted elements (connecting rods, connecting rods, references, combiner), are replaced by three cables (11) for the cyclic and a cable (12) for the collective. These cables are based on the cable stops (20) installed on the helicopter structure, and at their other end on the intermediate plate (1) or on the cable support (15) of the fork (7). ). The movements of souls are controlled by the cyclic stick (18) and the collective handle (19). Regarding the settings, the only interventions will now be and only at the level of the mixing board. The fork (7) being immobilized in the low position, bearing on the stop or stops (9), and the rotating part of the swashplate (2) maintained parallel to the intermediate plate (1) by three pins can be, by means of the usual step rods (4), adjust the zero of each blade and, by means of the adjustment devices of the sleeves (13) and webs (14), make possible fine adjustments of the positions of the two sleeves. The combination plate system significantly lighten the device by removing connecting rods, rods, references, combiner. The system makes it possible to have considerably simplified adjustments since the only interventions will be done with three pins only at the level of the mixing plate, one thus avoids to use many pins, shims, of positioning tools to immobilize all the linkages, In the case of light or ultra light helicopters, the cables directly animate the swashplate (2) and the intermediate plate (1), for heavy helicopters, the cables animate the distributors of the hydraulic servocontrols (21), hitched on the fork or the swashplate, if the necessary efforts are too important. We can also consider the use of mounted electric cylinders instead of hydraulic servo-controls (21). See Figure 5. The device can be adapted to all types of rotors, whether the swashplate is at the rotor head or at the foot (in case the pitch controls are in the rotor mast), the number of blades is even or odd and regardless of the direction of rotation of the rotor.

The floor is now free of any linkage and considering that the path of the cables is adaptable, it is possible, by placing a window between the feet of the driver, greatly facilitate the work with the sling avoiding the driver to take physically binding positions , tiring and above all that do not allow a correct vision of the work in progress. Regarding the anti-torque rotor lifter, the current controls are already cable for the most recent helicopters, this part will not be developed here.

In a more modern perspective, flying using this new type of combiner will benefit from mini-sleeves installed on arms integrated in the driver's seat. The left stick would manage the collective pitch of the main rotor, that is to say the up and down, and, by the possibility of tilting it to the right or to the left, the collective pitch of the anti torque, it that is, right-left pivoting of the helicopter (yaw). The right handle would handle the cyclic pitch of the main rotor that is to say all the translations of the device, each round could receive additional commands. The advantages of this latter provision are numerous: easy control by means implementing symmetrical steering positions (compared to the current physically binding positions for the pilot). Another important advantage of this mini-slew steering system is that it allows access to helicopter control for the physically disabled, paraplegic, amputees, etc. since the use of the feet is no longer necessary, the lace being provided by the left sleeve. INDUSTRIAL APPLICATION This invention is characterized by great simplicity, which is what makes it interesting. This device can be adapted without difficulty on the helicopters with course facilities at the rotor mast. The realization of the intermediate plateau does not pose any particular technical problem. The swashplate proposed here is similar to those used on current helicopters, so one can manufacture a combiner plate without undertaking expensive studies if not those relating to the mounting of the swashplate on the intermediate plateau. As for the cables, these are widely used on modern helicopters, generally to control the pitch variation of the anti-torque rotor. For heavy helicopters, the use of cables to control hydraulic servo drives is already common, in this type of control, there will also be no need for expensive studies.

Claims (10)

CLAIMS1) Device used to control cyclic and collective pitch variations for helicopter rotors, called combinator platter, characterized in that it comprises an intermediate plate (1), assembled to the swashplate (2) and whose movements are initialized by cables (11, 12) connected to the flight controls (18, 19, 22, 23), which transmit the movements of the pilot, thus allowing the cyclic and collective variations of the pitch of the blades via the rods ( 4). 2) Device according to claim 1 characterized in that the combiner plate comprises an intermediate plate (1) which supports the swashplate (2), the pivoting of the fork (7) initializes the vertical movements of the assembly called combiner plate. 3) Device according to claim 2 characterized in that the swashplate (2) is mounted on a sphere, integrated with the intermediate plate (1), this allows its inclination in all directions to ensure through the rods rods (4) the cyclic inclination of the rotor blades. 4) Device according to claim 2 characterized in that the pivoting of the fork (7) on its support (15) allows the sliding of the intermediate plate (1) on the optional bearing (6) of the sleeve of the mast (5), while that immobilization in rotation of the intermediate plate (1) is provided by rods (8). 5) Device according to claim 1 characterized in that all commands are initialized by means of cables (11, 12) and that "cable" means an assembly consisting of: a sheath terminated at each end by ball joints (10) to compensate for possible delignations and devices to refine the settings (13), each sheath arrives on supports either fixed (15, 20) or movable (1), a soul, responsible for causing the displacement of the controlled object, the soul is provided at each end of a junction allowing fine adjustments (14) and able to compensate for any delignations, the sliding of the souls are caused by the actions of the pilot on the handle (18). ) via the rudder (22) and the conjugation shaft (23) for the cyclic, as well as on the handle (19) for the collective, the edger and adjustment compensation devices (10, 13) are found at the level cable stops (20), the di Offset compensation and adjustment devices (14) are found at the level of the rudder (22), the conjugation shaft (23), the collective handle (19). 6) Device according to claim 1, 2 and claim 4, characterized in that the fork (7) which controls the movements of the intermediate plate (1), is controlled by the collective cable (12) whose sheath is supported on the support (15) via the ball (10) to compensate for possible delimitation and fine-tune the settings (13), the fork (7) has one or more adjustable stops (9) for adjusting its position in the configuration of the collective zero, to then allow the adjustment of the blades to their zero position via the rods (4), CLAIMS the sliding of the core of the collective cable (12) is caused by the actions of the pilot on the collective handle (19) which thereby causes the inclinations of the fork so the sliding of the combiner plate (1) on the bearing (6) of the sleeve of the mast (5). The core of the collective cable (12) is provided at each end with a junction allowing fine adjustments (14) and capable of compensating for any delignations, 7) Device according to claim 1, 2, 3 and claim 4, characterized in that the swashplate (2) which controls the usual pitch rods (4) is itself controlled by the cables (11) whose number is at least two but preferably three, which replace the usual control rods: the cable sheaths are supported on the intermediate plate (1), by means of the ball joints (10) to compensate for possible delignations and allowing refining the settings (13), the sliding of the souls in their sheaths, initialized by the pilot by means of the cyclic stick (18) via the rudder (22) and the conjugation shaft (23) allow the inclinations in all directions of the cyclic plateau (2), necessary for the cyclic variation of pitch, the cores are provided with a junction allowing fine adjustments (14) and able to compensate for any delocalisations, 8) Device according to claim 6 characterized in that the rotating part of the swashplate is rotatably connected to the rotor mast by the compass (17), while the non-rotating part is connected to the intermediate plate by the compass (16). 9) Device according to claim 3 and claim 4 characterized in that the control of the intermediate plate (1) can be done either directly by the cable (12) or by means of a servo (19) driven by this same cable in the case where the system described is used on heavy helicopters, likewise, the control of the swashplate can be done either directly by the cables (11), or by means of servo commands (21) controlled by these same cables in the case where the system described is used on heavy helicopters, 10) Device according to any one of claims characterized in that the mixing plate (1) can be controlled from the traditional controls of helicopters namely the cyclic stick (18), the collective handle (19), with an adaptation that eliminates the connecting rods and angles and of course the traditional combiner to replace them with the cables (11, 12) described in the preceding claims.