JPH06264701A - Fluid machine - Google Patents

Abstract

PURPOSE:To provide a fluid machine of a simplified constitution having a high efficiency under wide conditions. CONSTITUTION:By structuring a fluid machine to be supported by a bearing 3 freely permitting rotation in the direction of changing the angle of incidence and provided with an aerofoil 14 having a shape to stabilize at the suitable angle of incidence against a flow of fluid, the aerofoil can automatically hold the suitable angle of incidence at all times corresponding to the change of relative fluid speed against the aerofoil consequented to the change of the working conditions and makes it possible to provide a fluid machine of a simplified constitution capable of maintaining a high efficiency under wide conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid machine, and more particularly to a fluid machine having wings such as an aircraft or ship propeller, a compressor, a pump, a turbine, a wind turbine and a water turbine.

[0002]

[Prior art]

Conventionally, blades have been widely used in fluid machines represented by propellers, turbines and the like. The widthwise distribution of the mounting angle of the blade is determined to be optimum at the design point. For this reason,
Under conditions other than the design point, the attack angle of the blade is not appropriate for the flow of fluid, and when converting mechanical energy to energy of fluid or converting energy of fluid to mechanical energy In doing so, the efficiency of is severely reduced. As a method to solve it, there is a method in which the blade mounting angle is changed by an actuator according to the operating state of the fluid machine at each time so that the attack angle of the blade is always appropriate for the fluid flow. is there.

However, in this method, a measuring unit including a velocity meter and a tachometer for measuring the operating state of the fluid machine, and a control unit including an actuator and a computer for controlling the attack angle of the blades. Is required, and it is difficult to apply it to an object with large restrictions such as weight, volume, and cost. It is an object of the present invention to provide a fluid machine having a simple mechanism, which is capable of maintaining high efficiency under a wide range of conditions, even for objects having severe weight, volume, and cost constraints. And

[0004]

The present invention is a fluid machine characterized by the following items. A fluid machine, which is supported by a bearing (3) that freely allows rotation in a direction that changes the angle of attack, and has a blade (14) having a shape that stabilizes at an appropriate angle of attack against the flow of fluid. As a specific example, there is a fluid machine characterized in that the moment _Maco about the aerodynamic center of the entire blade (14) is positive and the position of the rotating shaft (2) is in front of the aerodynamic center. .

As a more specific example of the blade shape, there is a fluid machine characterized in that the widthwise end portion of the blade has a shape extending rearward in the direction of the relative velocity with respect to the fluid. In this case, lift force is generated. Section (12) and angle of attack control section (13)
There is a fluid machine characterized by using an airfoil in which the moment coefficient around the aerodynamic center of each airfoil is zero. A fluid machine according to claim 1 or 2, wherein an airfoil having a positive moment coefficient about the aerodynamic center is used, and the position of the rotating shaft (2) is set slightly ahead of the aerodynamic center. In this case, there is a fluid machine characterized in that the trailing edge of the blade has a shape that jumps up.

Further, a further improvement in efficiency can be achieved,
There is the above fluid machine characterized in that the shape of the blade is variable. As an example of products of these fluid machines, it is necessary to have a blade that is supported by a bearing that freely allows rotation in the pitch direction and that has a shape that stabilizes at a pitch angle that generates thrust in the forward direction when moving forward while rotating. There is a characteristic propeller. In addition, it is supported by a bearing that allows rotation in a direction that changes the angle of attack, and has a blade with a shape that stabilizes at the angle of attack that generates a moment around the main rotation axis in the fluid flow. There is a turbine that does.

FIG. 1 shows a diagram for explaining the basic structure of the fluid machine according to the present invention. As shown in FIG. 1 (a), a blade (14) of a fluid machine is supported via a rotating shaft 2 by a bearing (3) which freely allows rotation in a direction in which the angle of attack is changed. The rotating shaft (4) is fixed to each other by a mount (5). In this example, the blade cross section of the blade element (1) of the fluid machine has a shape in which the blade element rear portion (blade trailing edge portion) (7) jumps upward with respect to the blade element front portion (6). .

In a blade with a trailing edge that jumps up like this example, the moment coefficient around the aerodynamic center becomes positive (in the direction in which the leading edge is raised, in other words, in the direction in which the angle of attack α increases), and the rotation axis By setting the position of (2) to the front of the aerodynamic center (close to the leading edge), the blade is stabilized at an angle of attack that generates a positive lift in a uniform flow. Generally, the moment coefficient around the aerodynamic center of a blade with a negative camber (negative camber ratio) becomes positive, and this tendency increases as the maximum camber position from the leading edge is closer to the trailing edge, and the lift-drag ratio deteriorates. Instead, in order to increase the moment coefficient, it is preferable to adjust the vicinity of the trailing edge so that the trailing edge jumps up. In order to increase the efficiency of the blade, it is desirable that the moment coefficient around the aerodynamic center of the blade be a small positive value of about +0.01 to +0.1. Therefore, the position of the rotary shaft 2 should be set to the aerodynamics of the blade. It is preferable to be slightly forward of the center.

The relationship between the shape and characteristics of various airfoils is IH
Abbott et al., Summary of AirfoilData, NACA Report N
o.824, (1945), IHAbbott and AEvon Doenhoff, Theo
ryof Wing Sections, Dover Publications, Inc., NY,
(1959), FWRiegels, Aero-foil Sections, Butterwort
It has been investigated in detail by hs, London (1961) and others. (When implementing the present invention, there are many cases where an airfoil having a negative camber is adopted, but for airfoils having a mirror image of each other with respect to the chord line, a y-coordinate axis perpendicular to the chord line is used. Since the angle of attack α, the lift coefficient C _L , and the moment coefficient C _M can be considered by reversing the signs,
Also in this case, the abundant data of the above-mentioned documents can be used. )

FIG. 2 shows an example of a twist angle distribution in the width direction of the blade and a schematic diagram when the fluid machine shown in FIG. 1 is used as a propeller or a pump. Further, FIG. 3 shows an example of a twist angle distribution in the width direction of the blade and a schematic diagram when the fluid machine shown in FIG. 1 is used as a wind turbine or a turbine. In this way, by changing the twist angle distribution in the width direction of the blade, the fluid machine shown in FIG. 1 can be used as both a propeller and a wind turbine. The number of wings may be any number. In this example, the rotation axis (2) of the blade is perpendicular to the main rotation axis (4),
The invention is likewise applicable to fluid machines in which the blade rotation axis (2) is parallel to the main rotation axis (4).

As seen in a marine propeller or the like, in order to suppress vibration that occurs when the flow field in which the fluid machine operates is not uniform with respect to the rotation angle around the main rotation axis (4), the rotation axis The coefficient of friction between (2) and the bearing (3) should be small. On the other hand, in order to suppress the high-frequency vibration of the blade, it is effective to increase the friction coefficient between the rotating shaft (2) and the bearing (3) to some extent. Further, even if two or more blades are connected to each other so that the distributions of the angles of attack of the blades with respect to the plane perpendicular to the main rotation axis have the same width direction distribution, it is effective in suppressing high frequency vibration. . In addition, in order to improve safety in case of damage to a part of the wing, the rotary shaft (2)
An upper limit and a lower limit may be set for the rotation angle of.

[0012]

In FIG. 1 (a), the blade cross section of the blade element (1) of the fluid machine has a shape in which the blade element rear portion (7) jumps upward. The reason for such a shape is When the blade element is placed in a uniform flow, the distribution of the pressure difference between the upper and lower surfaces of the blade becomes as shown in Fig. 1 (b), and at a certain angle of attack that produces lift as a whole blade element, the rotation axis of the blade (2) In order to cancel the moment acting from the front part (6) of the blade element (the moment acting in the direction to reduce the attack angle of the blade element) around the is there. In other words, this is because the moment coefficient around the aerodynamic center of the blade element is positive. By doing so, the blade element supported by the rotating shaft (2) is
As shown in (b), the fluid is stabilized in a state having an angle of attack that generates lift in the flow. At this time, the position of the rotary shaft (2) becomes the wind pressure center.

In this example, the lift force of the entire blade element is the lift force (8) acting on the blade element front part (6) and the lift force of the blade element rear part (7).
Equal to the resultant force with the negative lift (9) acting on. Since the point of action of the lift force (9) is farther from the rotation axis (2) than the point of action of the lift force (8), it is possible to generate a moment that suspends the lift force (8) with a smaller force.

Here, for example, taking a propeller as an example, it is seen from the blade element that an increase in the rotational angular velocity of the main rotating shaft of the propeller and a decrease in the fluid inflow velocity (or the propeller surface forward velocity) occur. The angle of attack with the fluid flow increases.
In this case, as shown in FIG. 4A, the downward force (9) acting on the rear portion of the blade element decreases, and the upward force (8) acting on the front portion of the blade element increases. As a result, a head-down moment (10) is generated around the rotation axis (2) and the attack angle of the blade is reduced. Conversely, when the angle of attack seen from the wing is reduced,
As shown in (c), the downward force (9) acting on the rear portion of the blade element increases, and the upward force (8) acting on the front portion of the blade element decreases.

As a result, the moment of raising the head (11) is generated around the rotation axis (2), and the angle of attack of the blade element is increased. In this way, the blade attack angle finally automatically falls to a certain angle as shown in FIG. 4 (b). Here, the wing element rear part (7) is appropriately flipped up so as to reach the angle of attack at which the efficiency of the fluid machine is maximized.

The principle of automatic adjustment of the angle of attack will be described from another angle with reference to FIG. Here, a case where the attack angle α of the two-dimensional blade is equal to or less than the stall angle, that is, the case where the following expression is satisfied will be described as an example. C _L = (dC _L / dα) (α-α ₀ ) C _D = C _Dmin + κC _L ² , κ> 0 where C _L is the lift coefficient, C _D is the resistance coefficient, and C _Dmin is the minimum value of the resistance coefficient. , Α is the angle of attack measured from a certain reference line of the blade section, α ₀ is the lift-free angle measured from the same reference line, κ is a positive constant, and (dC _L / dα) is the lift inclination. Since the drag coefficient is sufficiently smaller than the lift coefficient, it is omitted below for simplification of description.

The position of the aerodynamic center (ac) of the blade element (1) is x
Let C _{Mac be} the moment coefficient around _ac and x _ac . Further, the position of the rotation axis (2) is x _b , and the moment coefficient around x _b is C _Mb . If the chord length of the blade element (1) is c and the lift coefficient of the blade element (1) when it is supported by the rotating shaft (2) in a uniform flow is C _L , then C _Mb = C _{Mac + (x b -x ac) /} c C L C Mb = 0 holds. Therefore, the lift coefficient C _L is given as follows. C _L = c · C _Mac / (x _ac −x _b )

On the contrary, _xb satisfies the following conditional expression. than _{x b = x ac -c · C} Mac / C L this formula, when the _{C L> 0, C Mac>} 0, a _{x b <x ac, C L} > 0, when the C _Mac = 0, x _{When b} = x _ac , and C _L > 0 and C _Mac <0, x _b > x _{ac. Therefore} , when the lift coefficient C _L is positive, the aerodynamic center is located behind the rotation axis (2). Is the moment coefficient C around the aerodynamic center
_{When the Mac} is positive. In order for the blade element (1) to be stable in the flow, the aerodynamic center must be located behind the rotation axis (2), which will be described below.

In order to stabilize the angle of attack at a certain angle, the value (dC _Mb / dα) obtained by partially differentiating the moment about the rotation axis (2) by the angle of attack must be negative. (DC _Mb / dα) = (x _b −x _ac ) / c · (dC _L / d
In (α), the lift gradient (dC _L / dα) is usually positive, so that (dC _Mb / dα) is negative, (x _b −x
_ac ) is negative, that is, the position of the rotation axis (2) must be in front of the aerodynamic center.

The relationship between the shape of the entire blade (14) and the automatic angle-of-attack adjusting function will be generally described with reference to FIG. Here, a case will be described in which the aerodynamic center C _{Mac0 of the} entire blade is made positive by adjusting the shape of the entire blade so that the blade (14) is stabilized at an angle of attack at which lift is generated in the operating state. In Figure, the aerodynamic center position x _ac a blade element, lift coefficient in when suitably secured across wing C _L, lift tilt (dC _L / dα), the inflow rate of fluid into the blade element v _i, wing blade element The chord length c is a function of the spanwise position y.

In a certain operating state (v / (Rf)), a point at which the moment around the point is constant is set as the entire blade (1
It is defined as the aerodynamic center x _{ac0 of} 4). x _ac0 can be expressed by the following equation.

[Formula 1] When the operating condition (v / (Rf)) changes, the shape of the distribution of v _{i in} the y direction changes, and the weight coefficient of each blade element continuously distributed in the y direction in the above formula changes, and the aerodynamic center The position of x _ac0 may change. Generally, the larger v / (Rf) is,
The contribution of the blade tip (near y = y ₁ ) to the total lift, the total moment, etc. becomes relatively small.

Also, the moment M _about this point x _ac0
ac0 can be expressed by the following equation.

[Number 2] The lift L to be obtained as a whole wing (14) When L _0, the position x _b0 of the rotary shaft (2) is, x _b0 = x _ac0 -M _ac0
/ L ₀ . The form of this equation is similar to the case of the blade element of the two-dimensional blade described above.

From the above, in order to stabilize the entire blade at the angle of attack at which lift is generated in the flow field, the aerodynamic center of the entire blade x
moment about _ac0 becomes positive, and the position x _b0 of the rotary shaft (2) may be more aerodynamic center front edge closer. The shape of the entire blade (14) is adjusted so that this condition is satisfied within the desired operating condition.

In the case where the blade element at each position in the width direction of the blade has a shape that seeks an optimum angle of attack in the flow field as in this example, it is preferable that the rigidity of the blade against twisting is small. In that case, as the structure of the blade, the blade main body is made of a fiber reinforced material containing more fibers in the chord length direction of the blade with respect to the width direction of the blade, and the mandrel of the mandrel is extended on the extension line of the rotating shaft 2. It is possible to have a structure that contains it.

When the mutual interference of the blades cannot be ignored, the blade cascade type is used. In this case, it is necessary to consider the moment coefficient of the blade in a distorted flow field with mutual interference of the blades. The adjustment mechanism is similar to that described above. Further, in a typical marine propeller or the like, the relative velocity vector of the fluid with respect to the blade is not perpendicular to the rotation axis (2), but rather faces a direction slightly away from the main rotation axis (4). The blade elements are preferably arranged along the velocity vector of the fluid, that is, in the direction in which the trailing edge is away from the main rotation axis (4) with respect to the leading edge. Note that the shape of the blade is not limited to this example, and any shape that is three-dimensional and can be stabilized in a state of an appropriate angle of attack in the flow of fluid when supported by a rotating shaft. It may be.

[0026]

EXAMPLE FIG. 7 shows an example in which the present invention is applied to a propeller. In this example, the lift generating part (12) was constructed as a symmetrical blade type, and the rotating shaft (2) was placed at the aerodynamic center position. Since it is a symmetrical blade, the moment coefficient C _Mac = 0 around the aerodynamic center (ac) of this blade element, and the lift generating portion (12) is stabilized in the flow at an arbitrary angle of attack α. On the other hand, the angle-of-attack control unit (13) attached to the rear of the rotary shaft (2) stabilizes at the angle of attack α = 0 in the flow. In other words, the angle of attack control section (13) takes an angle of attack α = 0 along the flow, and the lift generation section (12) makes the angle of attack corresponding to the attachment angle β of the angle of attack control section (13). α will be taken. At the design point, the lift generation unit (1) is set so that the lift generation unit (12) takes an appropriate angle of attack α with respect to the relative velocity vector of the fluid with respect to the blade.
2) The wing width distribution of the twist angle β with respect to the attack angle control section (13) is given. Note that the airfoil of the lift generation section (12) does not have to be a symmetrical airfoil, but may be any airfoil having a large moment-coefficient and a large lift-to-drag ratio, such as M-6.

FIG. 8 shows the distribution of the attack angle α of such a propeller under some operating conditions. In the figure, the dotted line represents the blade width direction distribution of the angle γ formed by the relative velocity vector of the fluid with respect to the blade element on the propeller rotating surface, and the solid line represents the blade width direction distribution of the angle θ formed by the blade element and the propeller rotating surface. There is. The angle of attack α is obtained as the difference between θ and γ. The fluid inflow velocity was v, the propeller rotation speed was f (rotation / unit time), the distance from the main rotating shaft 4 was r, and the propeller radius was R. At each position, the angle γ formed by the relative velocity vector of the fluid with respect to the blade element on the propeller rotation surface is
It was calculated approximately as shown in the figure.

In various flow fields, the angle-of-attack control unit (13) automatically takes an angle θ (= γ) that substantially matches the flow of the fluid there.
Is determined as a value obtained by adding the twist angle β to θ of the angle-of-attack control unit. In this example, the distribution of the attack angle α in the span direction is obtained at v / Rf = 1.0. From the figure, v / Rf = 0.
It can be seen that this propeller is operable even at 5,1.5. If the rotary shaft (2) is restrained like a general fixed pitch propeller, the design point v / Rf = 1.0
In the spanwise distribution of the angle θ formed by the blade element and the propeller rotating surface optimized by, the attack angle α becomes large at v / Rf = 0.5 and the blade stalls, and at v / Rf = 1.5. The angle of attack becomes negative and negative propulsive force is generated, and in any case, the efficiency is extremely reduced.

Generally, a prime mover has a rotation speed that maximizes efficiency or a rotation speed that maximizes output. Therefore, in order to maximize the performance of a prime mover that is not equipped with a transmission, the propeller must have a maximum speed. It is preferable that the rotation speed be constant regardless of the operating conditions. On the other hand, the angle θ formed by the blade element and the propeller rotating surface increases, and the component of the lift acting on the blade element parallel to the propeller rotating surface also increases, so the angle of attack α that is possible with the same prime mover output and rotational speed α Is getting smaller. That is, as v / Rf increases and γ increases, the optimum value of the attack angle α decreases. As can be seen from FIG. 6, according to the present invention, v / Rf increases, γ increases, and the attack angle α tends to decrease.

However, according to the present invention, as shown in FIG. 8, when the distribution of the helix angle β in the blade width direction is invariable, when the operating conditions of the propeller change significantly, the blade angle of attack distribution deviates from the optimum angle of attack. I understand. For example, v / Rf = 1.5
At, the angle of attack α is negative near the root of the propeller blade. Note that this problem also applies to a normal variable pitch propeller. In the vicinity of the blade root near the main rotation axis (4), the angle of attack α changes greatly due to changes in the operating conditions of the propeller, so it is preferable to use an airfoil with a large thickness ratio to prevent stall. This is consistent with the requirement for strength.

NACA63 ₃ -018 has a large leading edge radius which indicates a trailing edge stall type of stall in which the change in lift upon stall is small.
The airfoil shape is preferable. The optimum value of the angle of attack α is the angle of attack that maximizes the lift-drag ratio, but if a malfunction such as the risk of stall occurs due to a change in assumed operating conditions,
It is also possible to take safety at the expense of lift-drag ratio. Materials for propeller blades include GFRP, CFRP, FR
Those conventionally used such as M and titanium alloys are suitable. For marine propellers, a titanium alloy that is tough and resistant to corrosion is suitable.

As a method for keeping the angle of attack α more optimal with respect to changes in the operating conditions of the propeller, as shown in FIG. 9, the blade is divided in the width direction and supported by two or more rotating shafts. There is. By doing so, it becomes possible to realize a more appropriate spanwise distribution of the attack angle α under a wider operating condition. The relative velocity v _i of the fluid incident on the propeller blade is approximately v _i = (2πrf ² + v ² ) ^0.5 from Fig. 8, and the dynamic pressure of the fluid is proportional to v _i ² , so the main rotation axis (4 The distance r from) is small and v _i is small, and the angle θ formed by the blade element and the propeller surface of rotation is large.

FIG. 10 shows a propeller in which a lift generating section (12) and an attack angle control section (13) are connected via gears (16, 17). In this example, an airfoil having a moment coefficient around the aerodynamic center of zero was used. The lift generating section (12) was provided with a rotating shaft (2) at its aerodynamic center position, and the attack angle control section (13) was provided with a rotating shaft (2) in front of its aerodynamic center position. As described above, also in this case, the angle-of-attack control unit stabilizes at the angle-of-attack of zero in the flow field, and the lift generation unit changes the angle-of-attack according to the angle mechanically connected to the angle-of-attack control unit. Will be taken. In order to suppress the generation of Karman vortices on the rotation axis (2) of the angle-of-attack control section (12),
A freely rotatable cover is provided as shown in the figure.

FIG. 11 shows an embodiment in which the present invention is applied to a wind turbine. At the design point, the lift force generation unit (12) has an attack angle control unit (13) so that the lift force generation unit (12) takes an appropriate attack angle α with respect to the relative velocity vector of the fluid with respect to the blade.
Gives the distribution of the helix angle β with respect to.

For example, in a propeller, an angle γ formed by a relative velocity vector of a fluid with respect to a blade element on a propeller rotating surface.
Becomes larger, the propulsion efficiency becomes smaller, and the optimum angle of attack α
Becomes smaller. Therefore, depending on the operating state of the fluid machine,
It is effective to change the twist angle β, that is, to change the blade shape. FIG. 10 shows an attack angle control unit (1
An embodiment is shown in which the mounting angle between 2) and the lift derivation part (13) is made variable by a servomotor.

FIG. 13 shows an embodiment in which the present invention is applied to a propeller of a radio-controlled model airplane. As shown in the figure,
90mm in length and 2 in width with appropriate relative pitch angle distribution
The attack angle control unit (13) is attached to the wing tip of the propeller blade (12) (lift generation unit) of 0 mm so as to extend rearward in the rotational direction so that the attack angle becomes relatively smaller. The two blades (14) manufactured in this manner are attached to a bearing (3) that freely allows rotation in a direction in which the angle of attack is changed by a rotation shaft (2) passing near the aerodynamic center of the thrust generating portion. This bearing (3) is the rotating shaft (4) of the prime mover.
It is fixed to the integrated mount (5).

By doing so, the lift generating section (12) of the propeller automatically takes an appropriate angle of attack for various airspeeds by the action of the angle-of-attack control section (13). Therefore, it becomes possible to generate a large thrust under a wide range of flight conditions. The reason for extending the angle-of-attack control unit 13 rearward in the rotation direction of the propeller is to move the point of action of the fluid force generated in the angle-of-attack control unit by the airspeed away from the rotation axis, so that this force rotates around the rotation axis (2). This is because the moment acting on the blade is increased and the angle of attack of the entire blade can be efficiently controlled. In this example, both the lift generation unit (12) and the attack angle control unit (13) used an airfoil having a zero moment coefficient around the aerodynamic center.

The distribution of the angle θ formed by the blade element and the propeller rotating surface shown in FIG. 13 moves up and down in parallel with the rotation of the rotating shaft (2). Not limited to the above embodiment, the present invention exerts a great effect by being applied to a fluid machine in which the fluctuation range of the operating condition is large and the weight, cost, and volume restrictions are large.

[0039]

As described above, according to the present invention, the bearing is supported by the bearing that freely allows the rotation in the direction of changing the angle of attack, and has a shape that stabilizes at an appropriate angle of attack against the flow of fluid. By adopting a fluid machine with wings, it is possible for the wings to automatically maintain an appropriate angle of attack automatically in response to changes in the relative velocity of the fluid with respect to the wings due to changes in operating conditions. Therefore, it is possible to provide a fluid machine having a simple mechanism that maintains high efficiency.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a basic configuration of a fluid machine according to the present invention.

FIG. 2 is a diagram for explaining an example in which a fluid machine according to the present invention is applied to a propeller.

FIG. 3 is a diagram for explaining an example in which a fluid machine according to the present invention is applied to a turbine.

FIG. 4 is a diagram for explaining the principle of automatic stabilization of the angle of attack according to the present invention.

FIG. 5 is a diagram for explaining the principle of automatic stabilization of the angle of attack according to the present invention.

FIG. 6 is a diagram for explaining the principle of automatic stabilization of the angle of attack according to the present invention.

FIG. 7 is a diagram for explaining an embodiment according to the present invention.

FIG. 8 is a diagram for explaining an embodiment according to the present invention.

FIG. 9 is a diagram for explaining an embodiment according to the present invention.

FIG. 10 is a diagram for explaining an embodiment according to the present invention.

FIG. 11 is a diagram for explaining an embodiment according to the present invention.

FIG. 12 is a diagram for explaining an embodiment according to the present invention.

FIG. 13 is a diagram for explaining an embodiment according to the present invention.

[Explanation of symbols]

1 Blade element of fluid machine 2 Rotating shaft supporting blade element (1) and entire blade (14) 3 Bearing freely allowing rotation in the angle of attack 4 Main rotating shaft 5 Mount 6 Blade element front part 7 Blade element rear part 8 Lifting force acting on the blade front (6) 9 Lifting acting on the blade rear (7) 10 Head down moment acting around the rotation axis (2) 11 Head raising moment acting around the rotation axis (2) 12 Lifting force generation unit 13 Angle of attack control unit 14 Whole wing, lift force generation unit + angle of attack control unit 15 Actuator that changes the angle between the lift force generation unit (12) and the attack angle control unit (13) 16 Lifting force generation unit ( 12) Gear that connects the angle of attack control section (13) 17 Gear that connects the lift generation section (12) and the angle of attack control section (13)

[Table 1]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display area F03B 3/14 7504-3H F03D 1/06 A 2105-3H F04D 29/30 A 8610-3H

Claims (9)

[Claims] 1. A wing (14), which is supported by a bearing (3) that freely allows rotation in a direction that changes the angle of attack, and has a shape that stabilizes at an appropriate angle of attack against the flow of fluid. Characteristic fluid machinery. 2. The moment M _ac0 about the aerodynamic center of the entire wing (14) is positive, and the position of the rotating shaft (2) is located in front of the aerodynamic center. Fluid machinery. 3. A widthwise end portion of the blade has a shape extending rearward in a direction of relative velocity with respect to a fluid,
The fluid machine according to claim 1 or 2. 4. An airfoil having a moment coefficient around the aerodynamic center of each blade element of zero is used as the airfoil of the lift generation section (12) and the attack angle control section (13). The fluid machine according to claim 3. 5. The fluid machine according to claim 1, wherein an airfoil having a positive moment coefficient about the aerodynamic center is used, and the position of the rotating shaft (2) is set slightly ahead of the aerodynamic center. . 6. The fluid machine according to claim 5, wherein the trailing edge of the blade has a shape that jumps up. 7. The fluid machine according to claim 1, wherein the shape of the blade is variable. 8. A blade having a shape that is supported by a bearing that freely allows rotation in the pitch direction, and has a shape that stabilizes at a pitch angle that generates thrust in the forward direction when it is advanced while rotating. propeller. 9. An airfoil having a shape that is supported by a bearing that freely allows rotation in a direction that changes an angle of attack and that stabilizes at an angle of attack that generates a moment around a main rotation axis in a fluid flow. Turbine characterized by.