CROSS-REFERENCE TO RELATED APPLICATIONS

This Patent Application claims priority from Italian Patent Application No. 102019000003911 filed on March 18, 2019, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a wind machine.

In particular, the invention relates to a wind machine with a vertical rotation axis of the type known as wind turbine .

PRIOR ART

As it is known, a vertical axis wind machine generally comprises a connecting structure, which is designed to be fixed to a fixed support, and a monolithic rotor, which is coupled to the structure, can rotate around a fixed vertical axis and is provided with a plurality of vertical blades, which are angularly distributed around the vertical axis. The rotor is coupled to a motion output shaft, which, in turn, is coupled to an operating machine operated by the wind machine .

In order to optimize the efficiency thereof, known wind machines further comprise a fixed solid screen, which is designed to delimit a wind inlet door or passageway leading the wind towards the rotor and to screen the part of the vertical blades, which, if they were hit by the wind, would generate, upon the rotor, a negative torque, which would counter the positive one generated by the remaining part of the blades.

Known wind machines finally comprise a directional element, known as fin, which orients the inlet passageway in the direction of the wind.

Known machines of the type described above, even if they are used, are scarcely satisfactory, especially because of the fact that the rotation speed of the rotor cannot be controlled in a precise manner, but changes upon variation of the wind speed.

In some solutions braking devices are known, which brake the rotor when the wind speed increases. However, these devices, some of them being scarcely efficient and reliable, cause the machine to be complicated and often large-sized and expensive.

Therefore, lack of control of the rotation speed of the rotor limits the field of application of the wind machine in some cases and even prevents the wind machine from being used in other cases.

SUBJECT-MATTER OF THE INVENTION

The object of the invention is to provide a wind machine which can solve the problem discussed above in a simple and economic fashion and, in particular, a wind machine in which the rotation speed of the rotor can be adjusted, in a continuous and precise manner, regardless of the wind speed and as a function of the features of the operating units that can be associated with the wind machine.

According to the invention, there is provided a vertical axis wind machine as claimed in claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanying drawings, which show a non-limiting embodiment thereof, wherein:

figure 1 is a schematic perspective view of a preferred embodiment of the wind machine according to the invention; figure 2 shows, in a cross-sectional view and on a larger scale, the wind machine of figure 1;

figure 3 shows, on a larger scale, a detail of figure 1 ; and

figures 4 and 5 show, in a plan view and with parts removed for greater clarity, the machine of figure 1 in two different operation conditions.

PREFERRED EMBODIMENT OF THE INVENTION

In figures 1 and 2, number 1 indicates, as a whole, a vertical axis wind machine.

The machine 1 comprises a fixed connecting frame 2, which is firmly connected to a fixed support structure 3 (figure 2) in a known manner.

The connecting frame 2 comprises a base plate 4, a cylindrical tubular body 5, which is firmly connected to the base plate 4 and extends upwards coaxially to a vertical axis 6.

With reference to figures 1 and 2, again, the machine 1 further comprises a rotary structure 8, which is coupled to the tubular body 5 so as to rotate around the axis 6 relative to the tubular body 5 itself in opposite directions.

In particular, the structure 8 comprises a lower connecting portion 9, which surrounds the tubular body 5 and is coupled to the tubular body 5 itself in a rotary manner and in an axially fixed position by means of a pair of bearings 10. The lower portion 9 comprises, in turn, a lower shaped plate 11, which, in plan view, is substantially L- shaped and is crossed by the axis in a point P where two arms 12 and 13 of the lower shaped plate 11 are joined.

With reference to figure 1, the arm 12 is a substantially straight radial arm tapered towards its free end, whereas the arm 13 is shaped arm, which extends both in radial and in tangential direction and has, in plan view, the shape of a circular sector, a dihedral angle A and a bending radius which are variable upon variation of the size of the wind machine.

The structure 8 further comprises an upper shaped plate 14, which is parallel to the lower shaped plate 11 and has, in plan view, the same geometry and the same dimensions as the lower shaped plate 11. The arms of the upper plate 14 are indicated with the same reference number as the corresponding arms of the lower shaped plate 11. Preferably, though not necessarily, the upper shaped plate 14 has a peripheral edge, whose projection in plan view coincides with the outer peripheral edge of the lower shaped plate 11.

The shaped plates 11 and 14 are spaced apart from one another along the axis 6 and are firmly connected to one another by a pair of cylindrical vertical uprights 15 and by a circular solid wall 16, which faces and is diametrically opposite the uprights 15. The uprights 15 and the walls 16 are part of the structure 8. In the example shown herein, the uprights 15 are beside one another and parallel to the axis 6 and have opposite ends, which are connected, in an integral manner, to free end portions of the respective arms 12.

The wall 16 has a straight generatrix G parallel to the axis 6 and a concavity facing the axis 6. The wall 16 conveniently has the same bending radius as the shaped arms 13 and is delimited by the same dihedral angle as the arms 13. The wall 16 is manufactured as one single piece or by means of different portions firmly connected to one another.

The machine 1 further comprises a known monolithic rotor 18, which is housed between the shaped plates 11 and 14 and coaxially to the axis 6.

The rotor 18 comprises a lower plate 19 and an upper plate 20, which are both coaxial and orthogonal to the axis 6 and are each arranged adjacent to a relative shaped wall 11, 14.

The rotor 18 further comprises a plurality of vertical blades 22, which are parallel to the axis 6, are distributed around the axis 6 and are firmly connected to the plates 19 and 20, namely without possibility of adjustment relative to the plates 19, 20.

In the example described herein, the rotor 18 comprises three blades 22 having substantially V-shaped cross sections orthogonal to the axis (figures 1, 4 and 5) .

With reference to figure 2, again, the lower plate 19 is firmly connected to the upper end of a motion output shaft 24 of the machine 1.

The shaft 24 crosses the tubular body 5 coaxially to the axis 6 and is coupled to the tubular body 5 in a rotary manner around the axis 6 and in an axially fixed position by means of bearings 25. The shaft 24 has a lower end portion, which projects under the plate 4 and is connected, in a known manner, to an input shaft 26 of a schematically shown operating or driven machine 27, for example an electric machine or a hydraulic machine and, in general, a driven machine .

With reference to figure 2, again, the upper plate 20 is coupled to the upper shaped plate 13 by means of a hinge pin 27 and a bearing 28.

With reference to figure 1, again, and, in particular, to figure 3, above the shaped plate 13, the machine 1 comprises a known directional member 28, which is designed to autonomously orient itself in the direction of the wind. The directional member 28 comprises an arm 30, which extends in a projecting manner parallel to the upper shaped plate 13 and has an end hinged to the upper plate 13 coaxially to the axis 6 by means of a bearing 31. The arm 30 carries, firmly connected to it, a fin body 32 extending in a radial manner and upwards from the arm 30 itself.

With reference to figure 1 and, in particular, to figure

3, the angular position of the wall 16 around the axis 6 and relative to the blades 22 of the rotor 18 is controlled by a control assembly, indicated, as a whole, with 33.

The control assembly 33 comprises an actuator device 34 and a control unit 35. The actuator device 33 is interposed between the directional member 28 and the rotary structure 8 and, in particular, between the directional member 28 and the arm 13 of the upper shaped plate 14.

The actuator device 34 comprises a linear actuator 36 conveniently, but not necessarily, an electric actuator and a mechanical transmission 37. The actuator 36 is hinged, on one side, to the arm 30 so as to oscillate around an axis that is parallel to the axis 6 and, on the other side, to a free end of a rocker arm 38 having an intermediate portion pivoting on the arm 30 so as to rotate around a fulcrum axis that is parallel to the axis 6. The rocker arm 38 is part of the transmission 37 and has the opposite end hinged to an end segment of a tie rod/strut 39, which is also part of the mechanical transmission 37 and whose opposite end is hinged to the arm 13. Conveniently, though not necessarily, the linear actuator 36 is housed inside a hollow end portion of the arm 30 (figure 3) . Regardless of its position, the linear actuator 36 is controlled by a control block 40 of the unit 35, which is configured to receive an electric signal proportional to the speed of the wind measured in the direction of orientation of the directional member 28 and a signal of rotation speed of the shaft 24, which are emitted by respective detectors, which are part of the control assembly 33, are known and are indicated with 41 and 42, respectively. According to a variant, the control assembly 33 comprises only one of the two detectors 41, 42. According to a further variant, the control assembly 33 comprises, alternatively or in addition to one detector or to both detectors 41, 42, a detector of the torque transmitted to the shaft 24. The operation of the machine 1 will be described starting from the condition shown in figure 4, in which the wall 16 is placed and held, by the assembly 33, in an angular limit stop condition and laterally delimits a wind inlet opening 45, which, in this condition, has a maximum size, thus allowing a wind flow to be let in and fed so as to cause the rotation of the rotor 18 in a counterclockwise direction in figure 4. In this condition, on the other hand, at least a portion of the wall 16 screens part of the blades 22 which, if they were hit by the wind, would generate, upon the rotor 18, a negative torque, namely a torque contrary to the positive torque generated by the wind flow entering the machine 1 through the opening 45, as visible in figure 4.

Starting from this condition, following a signal received by the unit 35 from one detector or both detectors 41, 42, the block 40, in any instant and even in a condition of wind direction change, controls the actuator 36, which rotates the wall 16 in a counterclockwise direction (figure 4) relative to the directional member 28, thus changing, as a consequence, the size of the opening 45. Therefore, the size of the opening 45 can be changed in a continuous manner until it reaches a minimum or zero value, shown in figure 5. Even in this condition, the wall 16 screens part of the blades so as to avoid the generation of the aforesaid negative torques upon the rotor 18. Owing to the above, it is evident that, during the rotation of the wall 16 around the axis 6, the positive thrust exerted by the air upon the rotor 18 is reduced and this allows for a continuous variation of the speed of rotation of the rotor 18 and, ultimately, of the speed of rotation of the shaft 24, until it reaches any desired value.

Furthermore, the simple rotation of the wall 16 around the axis 6 eliminates at the root the need to rely on braking devices or apparatuses, thus actually allowing the machine to work in extremely high wind conditions, for example exceeding 12 m/s, in which traditional machines do not operate, especially to preserve their structural integrity.

The absence of braking devices or apparatuses generates a machine with reduced dimensions and weights, which also ensures a high efficiency and reliability. The efficiency and reliability are also consequent to the presence of one single linear actuator, which, by the way, is arranged in a protected position and does not normally require periodic maintenance interventions, just like the lever transmission, which could be different from the indicated herein or not be provided, does not need particular interventions.

Owing to the above, it is evident that the machine 1 described above can be subjected to changes and variants, without for this reason going beyond the scope of protection defined by the independent claim. In particular, the wall 16 could not be a completely solid wall, but it could comprise a portion having one or more calibrated or non-calibrated openings for the passage of air.

Furthermore, the wall 16 could be rotated around the axis 6 by a moving assembly which is different from the one described herein by way of example, for instance by means of an angular motor.

Finally, the wall 16 could be rotated in a non- continuous manner, hence in a discrete manner, or it could not be manufactured as one single piece, hence with different parts firmly connected to one anther.

Moreover, the rotary structure could be different from the one indicated herein, though always with the aim of allowing for a variation of the air inlet opening 45 letting air into the machine.

Finally, it is evident that the features of the wind machine 1 described above, in particular the reduced dimensions and weight, allow the machine to be particularly suited for the generation of electric energy, in general, and for the production of electric energy in single housing units, in particular.