Helicopter

065 656 U

DESCRIPTION

Helicopter.

Object of the invention

The present disclosure relates to an improved helicopter.

The disclosure is basically about a helicopter. In particular, although not exclusively, it refers to a toy helicopter, and in particular to a remote controlled model airplane helicopter or a toy helicopter.

Background

It is known that a helicopter is a complex machine which is unstable and as a result difficult to control, so much experience is required to operate such helicopters safely without mishap.

Typically, a helicopter includes a body, a main rotor, and a tail rotor.

The main rotor provides an upward force that keeps the helicopter in the air, as well as a lateral or forward or backward force to steer the helicopter in the requested directions. This can be done by varying the angle of incidence of the main rotor propeller blades cyclically with each revolution of the main rotor.

The main rotor has a natural tendency to drift out of position, which can lead to uncontrolled movements and a crash of the helicopter if the pilot loses control over the direction of the helicopter.

Solutions to reduce the effect have heretofore been provided, including the application of stabilizing rods and weights to the tips of the propeller blades.

All these solutions make use of the known phenomenon of gyroscopic precession, caused by the Coriolis force and centrifugal forces to obtain the desired effect.

The tip rotor is not at all insensitive to this phenomenon, since it has to prevent the body from rotating around the rotor drive axis as a result of the rotor's resistance torque on the body.

For this purpose, the tail rotor is installed such that it develops a lateral thrust that has to counteract the above-mentioned resistance torque of the rotor, and the helicopter is provided with means that have to allow the pilot to control the lateral thrust in such a way as to determine the flight position around the vertical axis.

Since the tail of the helicopter tends to rotate around the main rotor drive shaft, even in the case of small variations in the main rotor torque, most helicopters are equipped with an autonomous mechanical or electromechanical system, as per For example, a gyroscope or the like, which automatically compensates for the drive of the tail rotor for unwanted turns.

In general, the stability of a helicopter includes the result of the interaction between:

- the rotation of the rotor blades; the movements of any possible stabilization rod; compensation of the resistance torque of the main rotor by means of the tail rotor;

- the system, for example, a gyroscope or the like to compensate for small undesired variations in the resistance torque of the main rotor; Y

- the control of the helicopter that controls the rotation speed of the main rotor and the tail rotor.

When these elements are practically in balance the pilot should be able to steer the helicopter as desired.

This does not mean, however, that the helicopter can fly by itself and can therefore maintain a certain flight or maneuvering position, such as for example flying at a fixed point or with slow movements, without the intervention of a pilot.

Furthermore, flying a helicopter usually requires intensive training and a lot of pilot experience, both for a real life-size helicopter as well as for a toy helicopter or a remote controlled model helicopter.

Description of the invention

The present disclosure aims to minimize one or more of the aforementioned disadvantages by providing a simple and inexpensive solution to automatically stabilize the helicopter, such that the operation of the helicopter is simpler and reduces as much as possible the need for a long pilot experience.

The helicopter should meet the following conditions to a greater or lesser degree:

(a) be able to return to its position of flying to fixed point in a stable way, in case of an unwanted disturbance in the flight conditions. Such disturbance can occur in the form of a gust of wind, turbulence, a change in the mechanical load of the body or rotors, a change in the position of the body as a result of an adjustment in the cyclical variation of the slope or angle of incidence of the main rotor propeller blades or a tail rotor direction or the like with a similar effect; and (b) the time required to turn to the stable position should be relatively short and the helicopter movement should be relatively small.

To this end, the disclosure deals with an improved helicopter that includes a body with a tail; a main rotor with propeller blades which are driven by a rotor shaft and which is pivotally mounted to the rotor shaft by means of a joint. The angle between the rotating surface of the main rotor and the rotor shaft can vary. A tail rotor is driven by a second rotor shaft that is oriented transverse to the rotor axis of the main rotor.

The helicopter is provided with an auxiliary rotor that is driven by the axis of the main rotor and that is provided with two vanes that extend mainly in line with its longitudinal axis. The "longitudinal" axis, is viewed in the direction of rotation of the main rotor, and is practically parallel to the longitudinal axis of at least one of the propeller blades of the main rotor or is located within a relatively small acute angle with the axis of propeller blade. East

ES 1 065 656 U auxiliary rotor is provided in a tiltable manner on an oscillating axis which is provided basically transverse to the rotor axis of the main rotor. This is oriented basically transverse to the longitudinal axis of the slabs. The main rotor and the auxiliary rotor are connected to each other through a mechanical joint, such that the rocking movements of the auxiliary rotor control the angle of incidence of at least one of the propeller blades of the main rotor.

In practice, it is found that such an improved helicopter is more stable and also stabilizes relatively quickly with or without reduced user intervention.

According to a different aspect of the disclosure, the helicopter becomes more stable by suspending the tail rotor with its rotor shaft in an oscillation that can rotate about an oscillatory axis. The axis of oscillation extends basically in the longitudinal direction relative to the body of the helicopter.

In case of malfunction or the like, in which the helicopter starts to rotate around the rotor axis of the main rotor in an undesired way, the tail rotor, as a result of gyroscopic precession acting on the rotating tail rotor as As a result of turning around the rotor axis of the main rotor, it would tilt the oscillation axis of the tail rotor at a certain angle.

By measuring the relative angular displacement of the oscillation and by using the measured signal as an input signal for a microprocessor that controls the main rotor drive and the tail rotor drive as a function of a stabilizing algorithm, the drive of the tail rotor can be adjusted to counteract the unwanted effect of the disturbance and thereby automatically restore stable flight conditions for the helicopter, with little or minimal pilot intervention.

In this configuration, the tail rotor is used basically as a gyroscope, such that the gyroscope of known helicopters can be omitted. This can also lead to significant weight savings.

The angle of incidence of the rotor in the plane of rotation of the rotor and the rotor axis can vary; and a rotating auxiliary rotor with the rotor shaft is for relative oscillatory movement around the rotor shaft. Different relative positions are such that the auxiliary rotor causes the angle of incidence of the main rotor to be different. A link mechanism between the main rotor and the auxiliary rotor causes changes in the position of the auxiliary rotor that translate the changes in the angle of incidence.

The propeller blades of the main rotor and the vanes of the auxiliary rotor respectively are connected to each other with a mechanical link mechanism that allows relative movement between the propeller blades and the vanes of the auxiliary rotor.

There are wings oriented transversely to a longitudinal axis of the helicopter body oriented transversely and downwards and a stabilizer oriented downwards on the tail of the helicopter. This facilitates stability on the ground.

For the purpose of explaining the characteristics of the disclosure, the following embodiments of an improved helicopter according to the disclosure are given by way of example only, without being in any way limiting, with reference to the accompanying drawings, in which:

Brief description of the drawings

Figure 1 schematically represents a helicopter according to the disclosure in perspective;

Figure 2 represents a top view according to arrow F2 in figure 1;

Figures 3 and 4 represent respective sections according to lines II-II and III-III of Figure 2;

Figure 5 represents a view of part of the rear rotor indicated in Figure 1 by F5 on a larger scale;

Figure 6 is a rear view according to arrow F6 in Figure 5;

Figure 7 represents a variant of the figure

1;

Figure 8 represents a variant of Figure 5;

Figure 9 represents a different view of the tail rotor of Figure 8;

Figure 10 represents a section of the helicopter;

Figure 11 schematically represents an alternative view of the helicopter according to the disclosure in perspective;

Figure 12 is a perspective view of the main rotor and the auxiliary rotor;

Figure 13 is a perspective view of the tail rotor and tail stabilizer in a second embodiment of the helicopter;

Figure 14 represents a side sectional view in the second embodiment of the helicopter;

Figure 15 represents a perspective view of the second embodiment of the helicopter;

Figure 16 represents a top view of the second embodiment of the helicopter;

Figure 17 is a rear view of the second embodiment of the helicopter;

Figure 18 represents a sectional view of the. second embodiment of the helicopter; along line 18-18 of figure 16.

Description of a preferred embodiment

The helicopter 1 represented in the figures by means of an example is a remotely controlled helicopter basically consisting of a body 2 with a lander and a tail 3; a main rotor 4; an auxiliary rotor 5 driven synchronously with the latter and a tail rotor 6.

The main rotor 4 is provided with means of what is called the rotor head 7 on a first rotor shaft 8 facing upwards which is contact-mounted on the body 2 of the helicopter 1 in a rotary manner and which is driven by means of a motor 9 and a transmission 10, in which the motor 9 is, for example, an electric motor that is powered by a battery 11.

The main rotor 4 in this case has two propeller blades 12 that are in line or practically in line, although it can also be composed of a greater number of propeller blades 12.

The inclination or angle of incidence A of the propeller blades 12, in other words the angle A formed by the propeller blades 12 as represented in Figure 6 with the plane of rotation 14 of the main rotor 4, can be adjusted since , the main rotor 4 is hingedly mounted on this rotor shaft 8 by means of a joint, such that the angle between the plane of rotation of the main rotor and the rotor shaft can vary freely.

ES 1 065 656 U

In the case of the example of a main rotor 4 with two propeller blades 12, the connection is formed by a stem 15 of the rotor head 7.

The axis 16 of this rod 15 is oriented transversely to the rotor axis 8 and basically extends in the direction of the longitudinal axis 13 of one of the propeller blades 12, and preferably forms, as shown in FIG. 2, an acute angle B with this longitudinal axis 13.

The tail rotor 6 is driven by a second rotor shaft 17 by means of a second motor 18 and a transmission 19. The motor 18 may be an electric motor. The tail rotor 6 with its rotor shaft 17 and its drive mechanism 18-19 is suspended on a movable part 20 that can rotate around the roll axis 21 which is fixed on the tail 3 of the helicopter 1 by two supports 22 and 23 .

The movable part 20 is provided with an extension 24 towards the base, which is held in a central position by means of a spring 25 when it is in a state of rest, in which the second rotor shaft 17 in this position is horizontal and oriented transverse to the first rotor axis 8.

At the lower end of the extension 24 of the movable part 20 a magnet 26 is provided, while opposite the position of the magnet 26 in the aforementioned rest state of the movable part 20 is fixed a magnetic detector 27 on the tail which facilitates the measurement of the relative angular displacement of the moving part 20 and therefore of the tail rotor 6 around the roll axis 21.

It is clear that this angular displacement of the movable part 20 can also be measured in other ways, for example, by means of a potentiometer.

The measured signal can be used as an input signal for a control box, which is not represented in the figures, which controls the driving mechanisms of the main rotor 4 and the tail rotor 6 and which is provided with a stabilizing algorithm that will give a counter-direction control when a sudden unwanted angular displacement of the tail rotor 6 around the roll axis 21, resulting from an unwanted rotation of the helicopter 1 around the rotor axis 8, is measured, so that it re-establishes the position of helicopter 1.

The helicopter 1 is also provided with an auxiliary rotor 5 which is driven substantially synchronously with the main rotor 4 by the same rotor shaft 8 and the rotor head 7.

The main rotor 4 in this case has two vanes 28 that are practically in line with its longitudinal axis 29, whereby the longitudinal axis 29, seen in the direction of rotation R of the main rotor 4, is practically parallel to the longitudinal axis 13 of the propeller blades 12 of the main rotor 4 or attaches a relatively small acute angle C with it, so that both rotors 4 and 5 extend more or less in parallel on top of each other with their propeller blades 12 and vanes 28 so to speak.

The diameter of the auxiliary rotor 5 is preferably smaller than the diameter of the main rotor since the vanes 28 have a smaller wingspan than the propeller blades 12, and the vanes 28 are substantially rigidly connected to each other. This rigid assembly that forms the auxiliary rotor 5 is provided in an oscillating manner on an oscillating shaft 30 which is fixed to the head of the rotor 7 of the rotor shaft 8. This is oriented transversely to the longitudinal axis of the vanes 28 and transversely to the rotor axis 8.

The main rotor 4 and the auxiliary rotor 5 are connected to each other by a mechanical connection that is such of the auxiliary rotor 5 the angle of incidence A of at least one of the propeller blades 12 of the main rotor 4. In the given example this connection It is formed by a rod 31.

This rod 31 is mounted articulated to a propeller blade 12 of the main rotor 4 with a clamping point 32 by means of a joint 33 and a lever arm 34, and with another second clamping point 35, located at a distance from the previous one, it is hingedly mounted to a vane 28 of the auxiliary rotor 5 by means of a second joint 36 and a second lever arm 37.

The clamping point 32 on the main rotor 4 is located at a distance D from the axis 16 of the stem 15 of the propeller blades 12 of the main rotor 4, while the other clamping point 35 on the auxiliary rotor 5 is located at a distance E of axis 38 of oscillating axis 30 of auxiliary rotor 5.

The distance D is preferably greater than the distance E, and approximately twice this distance E, and both clamping points 32 and 35 of the rod 31 are located seen in the direction of rotation R, on the same side of the blades. propeller 12 of main rotor 4 or vanes 28 of auxiliary rotor 5, in other words, both are located in front of or behind the propeller blades 12 and vanes 28, viewed in the direction of rotation.

Also preferably, the longitudinal axis 29 of the vanes 28 of the auxiliary rotor 5, seen in the direction of rotation R, adjoins an angle F with the longitudinal axis 13 of the propeller blades 12 of the main rotor 4, whose angle F includes It is of the order of a magnitude of 10 °, so that the longitudinal axis 29 of the vanes 28 carries the longitudinal axis 13 of the propeller blades 12, seen in the direction of rotation R.

The auxiliary rotor 5 is provided with two stabilizing weights 39 which are each fixed to a vane 28 at a distance from the rotor axis 8.

Furthermore, the helicopter 1 is provided with a receiver, so that it can be controlled from a distance by means of a remote control that is not shown.

As a function of the helicopter type, it is possible to achieve the most appropriate values ​​and relationships of the angles B, F and G by experimentation; the relationship between the distances D and E; the size of the weights 39 and the ratio of the diameters between the main rotor 4 and the auxiliary rotor 5 so as to guarantee maximum self-stability.

The operation of the improved helicopter 1 according to the description is as follows.

In flight, the rotors 4, 5 and 6 are driven at a certain speed, as a result of which a flow of air relative to the rotors is created, as a result of which, the main rotor 4 generates an upward force so that causes the helicopter 1 to rise or fall or hold at a certain height, and the tail rotor 6 develops a laterally oriented force that is used to steer the helicopter 1.

It is impossible for the main rotor 4 to adjust as well, and it will rotate in the plane 14 in which it started, usually the horizontal plane. Under the influence of gyroscopic precession, turbulence and other factors4

ES 1 065 656 U res, it will carry an undesired arbitrary position if it is not controlled.

The rotating surface of the auxiliary rotor 5 can assume another inclination relative to the rotating surface 14 of the main rotor 8, whereby both rotors 5 and 4 can assume another inclination relative to the axis of the rotor 8.

This difference in inclination can originate any internal or external force or any disturbance.

In a situation where the helicopter 1 is suspended in a stable fixed point, over a point in the air without any disturbing external or internal force, the auxiliary rotor 5 is kept rotating in a plane that is basically perpendicular to the rotor axis 8.

However, if the body 2 is pushed out of equilibrium due to any disturbance, and the rotor shaft 8 rotates out of its equilibrium position, the auxiliary rotor 5 does not immediately follow this movement, since the auxiliary rotor 5 can move freely around oscillatory axis 30.

The main rotor 4 and the auxiliary rotor 5 are positioned in such a way that a rocking movement of the auxiliary rotor 5 is translated almost immediately on the slope or angle of incidence A of the propeller blades 12 to be adjusted.

For a two-bladed main rotor 4, this means that the propeller blades 12 and the vanes 28 of both rotors 4 and 5 can be basically parallel or, seen in the direction of rotation R, include an acute angle with another of per example 10 ° in the case of a large main rotor 4 and a smaller auxiliary rotor 5.

This angle can be calculated or determined by experimentation for any helicopter 1 or type of helicopter.

If the axis of rotation 8 assumes another inclination than that corresponding to the aforementioned position of equilibrium in a situation in which the helicopter 1 is suspended at a fixed point, the following happens:

A first effect is that the auxiliary rotor 5 will first try to preserve its absolute tilt, as a result of which the relative tilt of the rotating surface of the auxiliary rotor 5 changes relative to the rotor axis 8.

As a result, the rod 31 will adjust the angle of incidence A of the propeller blades 12, so that the upward force of the propeller blades 12 will increase on one side of the main rotor 4 and decrease on the diametrically opposite side of this rotor. principal.

Since the relative position of the main rotor 4 and the auxiliary rotor 5 are selected a relatively immediate effect is obtained. This change in upward force ensures that rotor shaft 8 and body 21 are forced downward into their original equilibrium position.

A second effect is that, since the distance between the distal ends of the vanes 28 and the plane of rotation 14 of the main rotor 4 is not equal in length and since the vanes 28 also cause an upward force, a greater pressure is created. between the main rotor 4 and the auxiliary rotor 5 on one side of the main rotor than on the diametrically opposite side.

A third effect plays a role when the helicopter starts to tip to the front, to the rear, or to the side due to a disturbance. As in the case of a pendulum, the helicopter will tilt to return to its original position. This pendulum effect does not generate any destabilizing gyroscopic force as in known helicopters that are equipped with an anti-roll bar oriented transversely to the propeller blades of the main rotor. It works to reinforce the first and second effects.

The effects have different origins although similar natures. These reinforce each other so that they automatically correct the equilibrium position of the helicopter 1 without any intervention from the pilot.

The tail rotor 6 is positioned in an oscillating manner and ensures additional stability and allows the tail rotor 6 to take over the function of the gyroscope that is frequently used in existing helicopters, such as model airplane helicopters.

In case of a disturbance, the body 2 can start to rotate around the rotor axis 8. As a result, the tail rotor 6 rotates at an angle in either direction around the roll axis 21. This is due to precession gyroscopic acting on the rotating tail rotor 6 as a result of the rotation of the tail rotor 6 about the rotor axis 8. The angular displacement is a function of the amplitude of the disturbance and therefore of the rotation of the body 2 about the axis of rotor 8. This is measured by the sensor

27.

The signal from the sensor 27 is used by a computer control box to counteract the failure and adjust the drive of the tail rotor 6 so as to cancel the angular displacement of the tail rotor 6 which is due to the disturbance.

This can be done by adjusting the speed of the tail rotor 6 and / or by adjusting the incidence angles of the propeller blades of the tail rotor 6, depending on the type of helicopter 1.

If necessary, this aspect of the disclosure can be applied separately, just as the aspect of the auxiliary rotor 5 can be applied separately, as illustrated for example by means of figure 7, which represents a helicopter 1 according to the disclosure having a main rotor 4 combined with an auxiliary rotor 5, but whose tail rotor 6 is of the conventional type, i.e. whose shaft cannot rotate in a moving part although it is mounted by contact relative to the tail 3.

In practice, the combination of both aspects makes it possible to make a helicopter that is very stable in any direction and flight situation and that is easy to control, even by people who have little or no experience.

It is clear that the main rotor 4 and the auxiliary rotor 5 do not necessarily have to be made as a rigid assembly. The propeller blades 12 and the vanes 28 can also be provided on the rotor head 7 such that they are mounted and can rotate relatively apart. In that case, for example, two rods 31 can be applied to connect at each moment a propeller blade 12 to a vane 28.

It is also clear that, if necessary, the joints and articulated joints can also be realized in other ways than those represented, for example by means of bending-torsion elements.

In the case of a main rotor 4 having more than two propeller blades 12, one should preferably be sure that at least one propeller blade 12 is basically parallel to one of the rotor vanes 28.

ES 1 065 656 U auxiliary. The main rotor joint 4 is preferably as a ball joint or as a stem 15 which is oriented basically transverse to the axis of the oscillating axis 30 of the auxiliary rotor 5 and which basically extends in the longitudinal direction of the propeller blade 12 in question which is basically parallel to the vanes 28.

The body includes wings oriented transversely in a longitudinal axis of the helicopter body. The wings 100 and 102 are oriented transversely and downwards whereby the ends 104 and 106 of the wings allow the helicopter body to be stabilized when it is on the ground.

A downward facing stabilizer 108 is seen on the tail of the helicopter. Figure 15 also shows a radio control unit for operation with the helicopter. This unit may have suitable computerized controls to indicate the operation of the motors driving the rotors and their relative positions.

The present disclosure is not limited to the embodiments described by way of example and represented in the accompanying figures. Several different variations in shape and scope and characteristics are possible. For example, instead of providing electric motors, other forms of driving forces are possible. A different number of blades can be provided on the rotors.

A helicopter in accordance with the disclosure can be made in all manner of shapes and dimensions as long as it remains within the scope of the disclosure. In this sense, although the helicopter has in some senses been described as a toy or model airplane helicopter, the features described and illustrated may have use in part or in whole in a life-size helicopter.