JP3244763B2 - Anemometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anemometer capable of changing the performance of the blade speed with respect to the wind speed.

[0002]

2. Description of the Related Art In recent years, the sun and wind energy have been reviewed again due to the growing interest in global environmental problems. When planning the utilization of wind energy, it is first necessary to statistically investigate the amount of wind energy existing over a long period of time, and there is a need for a measuring device capable of collecting accurate data such as wind speed. Conventional anemometers directly connect a load such as a small windmill and a DC generator, and indicate the wind speed by the number of rotations or the output of the generator. The relationship between the rotation speed of the blades and the wind speed varies depending on the load, and the output of the anemometer is extremely small, so that it is susceptible to friction loss and the like. It is difficult to achieve wind speed and rotation speed characteristics.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art without using a load having a large frictional loss such as a generator and the like, and in particular, the characteristics of an anemometer.
An object of the present invention is to provide an anemometer capable of arbitrarily finely adjusting a characteristic curve of the rotation speed of a blade with respect to a wind speed.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a windmill equipped with a wing rotating by receiving wind and a means for detecting the number of revolutions of the wing. A cylindrical member made of a metal material coaxially connected to the rotation shaft, and a pair of permanent magnets disposed on the inner peripheral surface thereof, and a predetermined gap is maintained between the pair of permanent magnets and the outer peripheral surface of the cylindrical member. And a cup member coaxially fitted to the cylindrical member, the cup member being mounted so as to be movable only in the axial direction within the casing of the anemometer main body, and adjusting the position of the cup member in the axial direction. Means for adjusting the relative amount of overlap between the permanent magnet pair, and an eddy current flowing on the surface of the cylindrical member when the cylindrical member rotating with the blade cuts off the magnetic flux generated by the permanent magnet pair. Use brake tor To generate, it is characterized in that to adjust the rotational speed characteristics of the wing.

[0005]

The cylindrical member rotating together with the wing cuts off the magnetic flux generated by the permanent magnet, so that the energy loss due to the eddy current flowing on the surface of the cylindrical member acts as a braking torque on the rotation of the wing. The brake torque corresponding to the magnitude of the eddy current loss can be adjusted by changing the position of the cup member in the axial direction and changing the relative overlapping amount between the permanent magnet and the cylindrical member. Can be easily controlled.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the anemometer according to the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes a casing constituting a main body of the anemometer, and the casing 1 is rotatably supported by a support column 2 horizontally and via a bearing 2a. A rotating shaft 3 is rotatably supported in the casing 1 coaxially via bearings 4a and 4b. A windmill blade 5 is fixed to the tip of the rotating shaft 3, and a pulse gear 6 is attached to the other end. In the vicinity of the pulse gear 6, there is arranged a pulse sensor 7 which constitutes means for detecting the rotation speed of the rotating shaft 3 together with the pulse gear 5.
The output of the pulse sensor 7 relating to the rotation speed of the wind turbine blades 5 is output from a signal outlet 8 to an external data processing device (not shown) via a lead wire wired in the support column 2. Has become.

On the other hand, an extension shaft 9 is connected to the rotation shaft 3, and a metal cylindrical member 10 is coaxially mounted on the rotation shaft 3 via the extension shaft 9. This cylindrical member 10
Is formed of aluminum, brass, copper, iron, or other metal having high conductivity.

FIG. 2 is an enlarged view showing a mounting portion of such a cylindrical member 10.
1 are loosely fitted. On the inner peripheral surface of the cup 11, a set of four permanent magnets 1
Are fixed to each other, a predetermined gap g is set between the permanent magnet 12 and the outer peripheral surface of the cylindrical member 10, and the cup 11 is movable via the screw shaft 13 in the axial direction. Installed. In this embodiment, in the case of the cylindrical member 10 (30 mm × 30 mmφ), the gap g
The eddy current loss was equal at 1 mm and 2 mm, and no eddy current loss was observed at 5 mm.

In this embodiment, the cup mounting seat 14 is provided.
A male screw cut into the screw shaft 13 is screwed into the screw hole of the screw member 13. Therefore, by rotating the screw shaft 13, the relative overlap amount x between the cylindrical member 10 and the permanent magnet 12 can be changed. It has become. Reference numerals 15a and 15b
1 shows a lock nut for fixing the position of the cup 11 by being fastened to the screw shaft 13, and 16 of FIG. 1 shows a cone of an anemometer serving also as a protective cover detachably engaged with the cup mounting seat 14. Part is shown.

The present embodiment is configured as described above. Next, its operation will be described. When the wind hits the windmill blade 5, the windmill blade 5 receives the wind and rotates at a rotation speed corresponding to the wind speed. The pulse sensor 7 outputs a pulse train signal proportional to the rotation speed of the wind turbine blade 5, and the wind speed data processing device that receives the pulse train signal calculates a wind speed value for each time and performs predetermined data processing. The obtained wind speed data is recorded as time data from the measurement start time to the end time on a recording medium such as a floppy disk or an IC memory card, and is also displayed on a display device such as a CRT display as wind speed data in units of 10 minutes. It is displayed graphically so that you can see the changes at a glance.

During the measurement of the wind speed, the magnetic flux generated by the permanent magnet 12 is cut by the cylindrical member 10 together with the rotating shaft 3, so that an eddy current flows on the surface of the cylindrical member 10 and Joule heat is generated. I do. The power absorption due to the eddy current loss acts as a braking torque on the rotating wind turbine blade 5. Since the heat energy generated by the eddy current is extremely small, the heat is naturally radiated into the atmosphere, and no adverse effect is caused by the temperature rise.

In FIG. 2, the distance between the end surface of the cylindrical member 10 and the end surface of the permanent magnet 12 is x, and the distance x is used to determine the relative overlap between the cylindrical member 10 and the permanent magnet 12. Expressed, the distance x corresponds to the eddy current. FIG.
Since the magnitude of the brake torque changes in accordance with the distance x, as shown in FIG. 7, the cup 11 is moved while rotating the screw shaft 13, and then the lock nuts 15a and 15b are tightened to fix the cup 11, so that the permanent magnet 12 Can be positioned at any position. That is, the magnitude of the brake torque can be arbitrarily adjusted.

In FIG. 4, a curve 1 represents a change in brake torque when two permanent magnets 12 are opposed to each other to form the polarity arrangement shown in FIG. FIG. 4 shows a change in brake torque when the polar arrangement shown in FIG. In addition, FIG.
FIG. 3B is an example in which the polarity is reversed. FIG. 3 above
It has been experimentally confirmed that the ratio of the magnitude of the brake torque is 1: 2: 3 for each of the magnet arrangements of FIGS. 3A to 3C.

FIG. 5 is a graph showing the relationship between the wind speed v and the number of revolutions N of the wind turbine blades 4 in the anemometer of the present embodiment. The relative overlap amount x ₁ between the cylindrical member 10 and the permanent magnet 12 is shown in FIG. Each of x ₂ and x ₃ is a straight line shown in FIG. In this case, the following relationship exists between the rotation speed N and the wind speed v. N = k (v−v ₀ ), where k is a proportional constant, and v ₀ is the starting wind speed of the wind turbine blade 4. By changing the overlap amount x, the proportional constant k can be set arbitrarily. And
Since the relative overlap amount x is adjusted using the screw shaft 13 as in this embodiment, fine control of the rotation speed performance through adjustment of the brake torque is possible.

Further, the magnitude of the brake torque is 0 in the case of the rotation speed N, and increases in direct proportion to the rotation speed N in the low rotation speed region, so that the starting wind speed v ₀ of the wind turbine blade 4 is extremely small. Since it can be maintained and the torque generated by the wind turbine blades 4 increases in proportion to (v-v ₀ ), a very appropriate load can be given as the load of the anemometer.

[0016]

As is clear from the above description, according to the present invention, it is possible to control the rotation speed of the wind turbine blades by using the brake torque due to the eddy current for the characteristics of the anemometer. It is possible to easily adjust the characteristics of the anemometer to a predetermined verification line. Then, the brake torque is always made to correspond to the extremely small generated torque of the anemometer, and the correct wind speed can be stably measured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an anemometer according to the present invention.

FIG. 2 is a partial cross-sectional view illustrating a mounting positional relationship between a cylindrical member and a permanent magnet provided on a cup member.

FIG. 3 is an explanatory diagram showing an example of an arrangement of permanent magnets in a cup member.

FIG. 4 is a graph showing a relationship between a relative overlapping amount of a cylindrical member and a permanent magnet and a brake torque.

FIG. 5 is a graph showing a relationship between a wind speed and a rotation speed of a windmill.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Support column 3 Rotating shaft 5 Windmill blade 6 Pulse gear 7 Pulse sensor 9 Extension shaft 10 Cylindrical member 11 Cup 12 Permanent magnet 13 Screw shaft 14 Cup mounting seat 15a, 15b Lock nut 16 cone

Claims (1)

(57) [Claims] 1. A wind turbine provided with a blade that rotates in response to wind, and a wind turbine type anemometer provided with a means for detecting the number of rotations of the blade, comprising: a cylindrical member made of a metal material coaxially connected to a rotation axis of the blade; A pair of permanent magnets disposed on the inner peripheral surface thereof, and a cup member coaxially fitted to the cylindrical member so as to maintain a predetermined gap between the pair of permanent magnets and the outer peripheral surface of the cylindrical member; Means for mounting the cup member movably only in the axial direction within the casing of the anemometer main body, and adjusting the position of the cup member in the axial direction to adjust the relative overlap amount between the cup member and the permanent magnet pair; When the cylindrical member rotating together with the wing cuts off the magnetic flux generated by the pair of permanent magnets, a brake torque is generated by using an eddy current flowing on the surface of the cylindrical member to adjust the rotational speed characteristic of the wing. I tried to do An anemometer characterized by the following.