JP2008063943A - Propeller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propeller including a propeller blade having such a pitch angle not at its root portion but at its blade end edge portion with respect to a relative flow in the rotational direction, as to raise the internal pressure of a fluid to thereby prevent generation of a cavity, a water bubble or cavitation at the blade root portion at the time of high-speed rotation so that the propeller can be rotated at a high speed by a small mover and can move a large amount of fluid backward. <P>SOLUTION: In the propeller 1 rotated by the prime mover, a bending base point line 2a having an equal radius of gyration is formed by connecting leading ends of a rotational front side end 2c and a rotational rear side end 2d on both sides of a back face of the propeller blade 2. A top end of the propeller blade 2 is tapered so as to be formed into a blade end slope portion 2b. An inclination boundary line 2e is formed to extend from the leading end of the rotational front side end 2c toward the blade root portion of the rotational rear side end 2d. An inclination back face 2f arranged on a rotational rear side with respect to the inclination boundary line 2e is inclined backward with the inclination boundary line 2e as the border so as to form the pitch angle with respect to the relative flow in the rotational forward direction. A rotational front side edge portion of the blade end slope portion 2b is curved and inclined backward from the bending base point line 2a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a propeller, and in particular, there is no pitch angle of the blade root portion of the propeller blade, and a pitch angle with respect to the relative flow in the rotation direction is formed at the blade edge, thereby increasing the internal pressure toward the axial center during high-speed rotation. The present invention relates to a propeller that eliminates the generation of cavities, water bubbles, and cavitation in the blade root, and that can rotate at a high speed and move a large amount of fluid backward with a small prime mover.

Conventionally, a screw propeller for an underwater propulsion device, for example, has a blade root inclined with respect to a main shaft and is largely twisted from the blade root to the blade tip. The ventilation fan has almost the same form. Further, a propeller such as Patent Document 1 in which the entire blade is inclined backward is also disclosed.
JP-A-8-072794.

The conventional marine screw has a large pitch angle at the blade root, and as a result, the plate thickness is set to be thick, and the water flow is twisted with the rotation and discharged to the back.
In addition, since the pitch angle of the blade root is large, if the plate thickness is increased and the rotational speed is increased, the water flow cannot flow along the pitch angle, causing a fluid separation phenomenon from the blade surface and reducing the internal pressure. In the process, cavitation (a phenomenon where cavities are formed and vortices are generated) occurs, and there is a difficulty in generating loud rotating sounds and bubbles.
Such a loss of twisting water flow and a loss of cavitation cause a large loss of rotational energy.
This invention has no twisting of the blade root of the propeller blade, a pitch angle is formed at the blade edge and the fluid internal pressure is increased, cavitation and rotation noise are less likely to occur, the rotation speed can be improved, and propulsion The object is to provide a propeller that can move a large amount of fluid with small energy, and a propeller for a wind turbine without rotating sound, such as a fan for air conditioning, a fan for ventilation, and a pump.

  Specific contents of the present invention are as follows.

  (1) A propeller that is rotated by a prime mover, and is a bent base line with equal turning radii so as to connect the front edge of the front end and the end of the rear end of both sides of the back of the propeller blade. Is set, the tip is tapered and the blade tip slope is set, the slope boundary is set from the tip of the front end toward the rear end of the blade root, and the rear of the blade is rotated behind the slope boundary. The inclined back surface set in the section is inclined backwards with respect to the inclined boundary line to form a pitch angle with respect to the relative flow in the pre-rotation direction. A propeller that is curved and inclined in the backward direction with the curved base line as the base point.

  (2) A propeller that is rotated by a prime mover, and the bent base line has a turning radius equal to each other so as to connect the front edge of rotation on both sides of the back of the propeller blade and the tip edge of the rotation rear end. Is set, the tip of the blade is tapered and the tip of the blade tip is set, the tilt boundary is set from the tip of the rear end of the rotation toward the front end of the tip of the blade root, and the front portion of the rotation is ahead of the tilt boundary. The inclined back surface is set at the boundary of the inclined boundary line, and the front edge of the bent base line is inclined forward to form a pitch angle with respect to the relative flow in the pre-rotation direction. The inclined part is a propeller whose front edge portion is curved and inclined in the backward direction with a bent base line as a base point.

  (3) A bending base line is set with equal turning radii so as to connect the leading edge of the front end of rotation and the rear end of the rear end of the propeller blade on both sides. The tip is tapered to form a blade tip inclined portion, and an inclined boundary line is set from the tip end of the front end to the rear end of the blade root. The set inclined front surface is inclined rearward to form a pitch angle with respect to the relative flow from the front direction, and the blade tip inclined portion has a front edge in the front direction with a bent base line as a base point. A propeller that is angled and curved.

  (4) A bending base line is set with an equal radius of rotation so as to connect the front edge of the front end of rotation on both sides and the front edge of the rear end of the propeller blade at the same distance. The tip of the blade is tapered to form a blade tip slope, and an inclined boundary line is set from the tip of the rear end of the rotation toward the front end of the blade root before rotation. The inclined front surface is inclined frontward to form a pitch angle with respect to the relative flow from the front direction, and the blade tip inclined portion has a front edge in the front direction with a bent base line as a base point. A propeller that is angled and curved.

  The present invention has the following effects.

(1) In the propeller according to the first aspect of the present invention, since the pitch angle with respect to the relative flow ahead of the rotation is formed in the portion near the blade tip from the middle of the blade length on the back surface of the propeller blade, the propeller When used as a water flow, the water flow is strongly pushed backward at the blade edge that is far from the propeller shaft with rotation, so that a high propulsive force can be obtained.
The blade root portion has no pitch angle, and the water pressure pushed axially by the blade tip inclined portion increases the internal pressure, so that no cavities or vortices of the water flow are generated and no rotating sound is generated.
Since the rotational efficiency is good, the prime mover can be made smaller. When used for fans such as ventilation fans and air conditioners, the prime mover can be made smaller.

(2) In the propeller of the invention described in claim 2, a bent base line is set at the rear blade end edge of the propeller blade, and the propeller blade is inclined backward from the bent base line to the blade end. Since the blade tip slope is formed, when used as a propeller, the diffusion of the fluid diffused in the centrifugal direction with rotation is suppressed by the blade tip slope and the water flow is pushed out toward the axis. Therefore, the internal pressure increases and cavitation does not occur.
With high-speed rotation, no cavitation or vortex of water flow occurs in the blade root without twisting, so there is no rotating sound.
Since the pitch angle is reduced, the thickness of the wing can be reduced and the rotational speed can be increased. Therefore, it is suitable for a propulsion device such as a ship and has high rotational efficiency, so that the prime mover can be downsized.

(3) Since the propeller of the invention described in claim 3 is formed with a blade tip inclined portion that is inclined in the front direction at the front blade end edge of the propeller blade, When the wind flow is received, the wind flow trying to diffuse in the centrifugal direction is suppressed by the blade tip inclined portion, and the rotational force is increased.
An inclined boundary line is set from the tip of the front end to the rear end of the blade root, and the inclined front surface of the rear part of the rotation is inclined rearward of the inclined boundary line from the front direction. Since the pitch angle with respect to the relative flow is formed, when the wind flow is received from the front, the inclined front surface having the pitch angle is pushed in the rotational direction by the wind flow, and is efficiently rotated to increase the shaft torque. it can. Further, since the rotational noise is low because of the low rotational resistance, it is suitable for wind turbines for wind power generators or water turbines.

  (4) Since the propeller of the invention described in claim 4 is formed with a blade tip inclined portion inclined frontward at the front blade end edge portion of the propeller blade, when used in a wind turbine, When the wind flow is received, the wind flow trying to diffuse in the centrifugal direction is suppressed by the blade tip inclined portion, and the rotational force is increased. An inclined boundary line is set from the tip of the rear end to the front end of the blade root, and the inclined front surface of the front part of the rotation is inclined forward from the inclined boundary. Since the pitch angle with respect to the relative flow is formed, when the wind flow is received from the front, the inclined front surface having the pitch angle is pushed in the rotational direction by the wind flow, and is efficiently rotated to increase the shaft torque. Since the rotation sound is quiet, it is suitable for wind turbines for wind power generators or water turbines.

  Examples of the present invention will be described. FIG. 1 is a rear view of a propeller according to the present invention, and FIG. 2 is a plan view. In the figure, the propeller 1 has four propeller blades 2 arranged at equal intervals on the boss 1a. The number of propeller blades 2 is not limited to this.

  The chord length of each propeller blade 2 is set to be substantially the same from the blade root to the blade edge. Folding is performed with an equal radius of rotation so as to connect the front edge 2c (right end in FIG. 1) at the left and right ends in FIG. 1 and the leading edge of the rear end 2d (left end in FIG. 1). A curve base line 2a is set.

The bent base line 2a is formed in the shape of a rotating arc of the part on the back surface of the propeller blade 2, and is gradually tapered from the bent base line 2a to the blade tip, and the tip end portion is inclined to the blade tip inclined portion 2b. It is formed as.
The blade tip inclined portion 2b is inclined gently toward the rear side of the propeller blade 2 with the bent base line 2a as an inclination base point, and the front edge portion of the blade is strongly curved and inclined backward.

The curve inclination angle of the front end portion of the blade tip inclined portion 2b varies depending on the length of the blade tip inclined portion 2b, but the tip of the blade tip inclined portion 2 is bent from the beginning to the vertical front surface of the propeller blade 2. Is set in a range of 15 degrees to 45 degrees.
The length of the blade tip inclined portion 2b from the bent base line 2a to the blade tip is 15% of the blade length of the propeller blade 2 in the figure, but is within the range of 15% to 60%. can do.

In FIG. 1, the tip of the front end 2c of the propeller blade 2 is in contact with the bent base line 2a, and an inclined boundary line 2e is formed from the intersection to the rear end 2d of the blade root. .
With the inclined boundary line 2e as a boundary, an inclined rear surface 2f having a pitch angle with respect to the relative flow in the rotational direction is formed by inclining the tip end of the rear end 2d portion of the propeller blade 2 toward the rear. ing. Although the inclined boundary line 2e is shown as a straight line in FIG. 1, it can be curved, for example, in a blade shape at the blade root portion.

As shown in FIG. 2, in the state where the longitudinal direction of the propeller blade 2 is horizontal, the plate thickness of the front end 2c portion of the rotation is gradually reduced from the blade root to the blade edge. In addition, the plate thickness of the rear end 2d portion is gradually reduced from the blade root to the blade edge.
With the tip of the propeller blade 2 facing upward, the inclined back surface 2f on the rear surface of the tip edge is formed with a pitch angle (P) in the range of 7 to 25 degrees relative to the relative forward flow. .

As a result, there is no pitch angle on the back surface of the blade root portion of the propeller blade 2, and the portion behind the inclined boundary line 2e from the blade root portion to the blade edge is gradually inclined backward to the rotation direction. On the other hand, an inclined back surface 2f having a pitch angle (P) is formed.
However, if necessary, the pitch angle of the blade root can be formed in the range of 0 to 4 degrees.

  When the propeller 1 is rotated clockwise in FIG. 1 as a propulsion device of the ship, the water flow that diffuses in the rotational centrifugal direction from the blade root portion is suppressed by the blade tip inclined portion 2b, and the propeller blade 2 on the rear surface of the propeller blade 2 The blade tip inclined portion 2b and the inclined back surface 2f having a pitch angle (P) are pushed backward so as to be beaten.

  The conventional screw has a strong pitch angle at the blade root, so at low speed rotation, water flows along the pitch angle, but at high speed rotation, the high speed flow water is a long distance along the surface with the pitch angle. The phenomenon of flying (peeling off from the pitch angle surface) occurs so as to enter the inside of the road curve and take a shortcut without flowing. As a result, a cavity is formed, the internal pressure is lowered, and foaming and noise are generated, but this is not generated in the propeller 1.

  That is, as the propeller 1 rotates, the blade root portion does not have a pitch angle with respect to the relative flow in the rotation direction. Therefore, the resistance of water is small, and the blade tip edge portion of the propeller blade 2 is rotated at high speed. Since the fluid is pushed toward the axial center at a high speed to increase the internal pressure, there is no cavitation that causes cavities, vortices, bubbles, etc., so that the rotor rotates silently without any noise.

  When the pitch angle (P) of the tip edge portion on the back surface of the propeller blade 2 is small, the resistance of water during rotation is small and the rotation speed of the propeller 1 can be increased. When rotating at high speed, the rotational speed of the centrifugal portion of the propeller blade 2 is large, and the thrust of the water flow in the centrifugal portion of the propeller blade 2 is large, so that the propulsive force becomes high. This propeller 1 is characterized in that the chord length of the propeller blade 2 is substantially the same and narrow from the blade root to the blade tip, but there is no pitch angle on the back surface of the blade root portion, and the blade edge portion of the inclined back surface 2f. The pitch angle (P) is also characterized by a gentle point.

  Due to this shape, the propeller blade 2 does not generate vortices or cavitation at the blade root without twisting, and has a narrow chord length and a gentle pitch angle (P) at the blade edge. , The blade tip inclined portion 2b suppresses the diffusion of the water flow and collects the water flow toward the axial center behind it, so that an efficient propulsive force can be obtained.

  When this propeller 1 is used as a fan, it can be rotated at a high speed without a wind noise with a small prime mover. Since air can be efficiently blown, it can be used for fans such as air conditioners and ventilation fans, and is suitable for a fan propulsion device for boats.

FIG. 3 is a rear view of the propeller showing the second embodiment, and FIG. 4 is a plan view. The same parts as those in the previous example are denoted by the same reference numerals and description thereof is omitted.
In the second embodiment, as shown in the drawing, the bent base line 2a of the propeller blade 2 is set to a portion corresponding to 40% of the blade length from the blade tip, and the length of the blade tip inclined portion 2b is 40% of the blade length. However, the present invention is not limited to this.

  As a result, the area of the inclined back surface 2f increases, and the area where the blade tip inclined portion 2b has a pitch angle (P) with respect to the relative flow ahead of the rotation is widened. The amount can be increased. The length of the blade tip inclined portion 2b with the bent base line 2a as the inclination base point can be set to 15% to 60% of the blade length, and when the blade tip inclined portion 2b is long, The inclination angle of the end inclined portion 2b is reduced.

FIG. 5 is a rear view of the propeller showing the third embodiment, and FIG. 6 is a plan view. The same parts as those in the previous example are denoted by the same reference numerals and description thereof is omitted.
In the third embodiment, the inclined boundary line 2e is set in the reverse direction. In FIG. 5, the tip end portion of the rear end 2d of the propeller blade 2 is in contact with the bent base line 2a, and an inclined boundary line 2e is formed from the intersection point toward the rotation front edge 2c of the blade root portion. .

  In FIG. 6, the front rotation-side end 2 c is made thinner from the blade root toward the bent base line 2 a of the blade tip edge, and is inclined in the front direction. With the inclined boundary line 2e as a boundary, the tip edge portion of the propeller blade 2 is inclined in the front direction to form a pitch angle (P) with respect to the relative flow in the pre-rotation direction. As shown in FIG. 6, the pitch angle (P) is formed in the range of 7 to 25 degrees with respect to the rotation direction with the tip of the propeller blade 2 facing upward.

In the third embodiment configured as described above, since there is no pitch angle at the blade root portion, cavities and vortices are not generated at the time of high-speed rotation, bubbles and rotating noise are not generated, and cavitation does not occur.
Further, since the rotation rear portion is wider than the inclined boundary line 2e in the blade root portion, it is excellent in rigidity and the overall plate thickness can be reduced, so that the resistance during rotation can be reduced.

Thus, when the propeller 1 is a propelling device, the propeller blade 2 is swung with water at a position close to the front surface at the bent base line 2a portion having the maximum chord length as it rotates. Using the inclined back surface 2f having a pitch angle to 2d, the propeller blades 2 are pushed backward, and the ship is propelled by the reaction.
At the time of rotation, the water flow pushed in the backward direction without being diffused in the centrifugal direction of the propeller blades 2 has a high water pressure, and the ship advances as the reaction.

  At the same time, the propeller blade 2 is naturally pushed in the rotation direction and rotated by the force of the water flow that slides in front of the propeller blade 2 and flows backward, so that the propeller 1 reduces the driving force of the prime mover. Can do. This is because when the wind current hits the propeller windmill, the propeller blade 2 is rotated by the force of the relative flow that strikes the front of the rotating propeller blade 2 in the same manner as the propeller blade 2 rotates.

  The conventional type screen twists and discharges water backwards. As a result, extra force is required to twist the water, resulting in a loss. In addition, the water flow that flows from the front to the back direction with respect to the water flow that is twisted and discharged to the back is not easily removed backward, causing water bubbles and cavitation, resulting in loss of rotational force.

  On the other hand, the propeller blade 2 of the present invention has no pitch angle at the blade root and no twisting of the water flow, so the resistance of water during rotation is small, and the blade edge has a moderate pitch angle. Since the water is pushed out to the back, the water flow is less likely to be twisted and smoothly flows, so that sound and water bubbles are less likely to be generated and the loss of rotational force is small.

Compared with the conventional type of screw, the propeller 1 of the present invention improves the rotational speed even with the same power, so that a motor with a smaller driving force can be used.
In addition, there is a bent base line 2a having the maximum chord length in the rotating centrifugal part of the propeller blade 2, and both the inclined back surface 2f and the blade tip inclined part 2b have a pitch angle (P). Efficient to move to the back.

  At the same time, the water flow that slides behind the propeller blade 2 and flows backward causes the water flow in the front to flow at a high speed behind the front due to the negative pressure generated along the front of the propeller blade 2 as it rotates. The action of the water flow is repeated such that the inclined back surface 2f of the propeller blade 2 is pushed back.

  As a result, the water flow in front of the propeller blade 2 is smoothly flowing to the back, so that the propeller blade 2 is rotated by the force of the strong water flow that slides in front of the propeller blade 2 and flows backward. The rotation speed of the propeller 1 is increased.

Since the propeller 1 is small and has high propulsive force, it is suitable for a propulsion device of a ship and can be used for steering by arranging a propeller shaft sideways at the tip of the ship.
Further, by changing the rotation radius of the propeller blade 2, it can be used for fans such as air conditioners and ventilating fans in addition to the fan propulsion device for boats corresponding to fluids having different masses such as water and air.

  In the case of a propeller, this fluid propeller 1 pushes out water or air to the back and moves forward by its reaction. However, when it is used for blowing air, there is no rotating sound. The amount of blown air is large, and the thickness of the propeller blade 2 can be reduced.

  In addition, since the prime mover can be reduced in size, it can be widely used for applications such as a fan of an air conditioner, a ventilation fan in a tunnel, a pump, or the like for moving a fluid backward.

FIG. 7 is a rear view of the propeller showing the fourth embodiment, and FIG. 8 is a plan view. The same parts as those in the previous example are denoted by the same reference numerals and description thereof is omitted.
The fourth embodiment is characterized in that the front end 2c and the rear end 2d at both ends of the propeller blade 2 are opened at a large angle.

  Accordingly, the area of the inclined back surface 2f is set wide. In FIG. 8, the pitch angle of the inclined back surface 2f with respect to the relative forward flow is a gentle inclination of about 15 degrees because the inclined back surface 2f is long in the longitudinal direction of rotation.

  The bent base line 2a has an arc shape, and the blade tip inclined part 2b has a gentle inclination with the bent base line 2a as a base, and the front edge of rotation is formed with a strong curved inclination. As shown in FIG. 8, the blade tip inclined portion 2b also has a pitch angle with respect to the relative flow ahead of the rotation.

  Thus, when the propeller 1 is rotated, the surfaces having the pitch angle of the inclined back surface 2f and the blade tip inclined portion 2b push the water flow backward, and the portion having a wide area with the pitch angle is Since the position is far from the shaft 3, the driving force is large.

FIG. 9 is a rear view of the propeller showing the fifth embodiment, and FIG. 10 is a plan view. The same parts as those in the previous example are denoted by the same reference numerals and description thereof is omitted.
In the fifth embodiment, the chord length of the tip edge portion is narrower than that of the propeller blade of the fourth embodiment. Since the plate thickness is thin and the entire plate is flat and has two blades, the rotation speed can be increased particularly in the above-described embodiment.

FIG. 11 is a front view of the propeller showing the sixth embodiment. The same parts as those in the previous example are denoted by the same reference numerals and description thereof is omitted. The sixth embodiment is for a wind turbine in which the rear surface in FIG. 1 is a front view and the rotational rear side is inclined rearward relative to the inclined boundary line 2e of the propeller blade 2.
When used in a windmill and receives wind on the front side of the propeller blade 2, the wind is received on the inclined front surface 2g having a pitch angle in the rear portion of the rotation relative to the inclined boundary 2e of the propeller blade 2, and rotates in the rotation direction.

In this case, the width of the flat blade root is wide, but the wind flow received on the flat surface is diffused in the centrifugal direction as it rotates, so that it does not become a burden of rotation.
The wind flow diffused to the rotating centrifugal direction of the propeller blade 2 is suppressed by the blade tip inclined portion 2b, and is gathered on the inclined front surface 2g having a pitch angle at the portion behind the inclined boundary line 2e, and the pressure is increased. To increase the rotational force of the propeller 1.

  Further, the inclined front surface 2g having the pitch angle of the rear portion of rotation from the inclined boundary line 2e is in contact with the inclined front surface 2g from the front because the tip of the rear end 2d is inclined backward in FIG. Thus, the wind flow that slides to the left rear is high speed, has a low air density, and has a negative pressure rather than the surroundings. Therefore, a larger amount of wind flows gather on the inclined front surface 2g than the surroundings, thereby increasing the rotational force.

  Along with the rotation, the wind flowing along the bent base line 2 a pushes the propeller blade 2 in the rotating direction, and the bent base line 2 a portion is located at the rotating centrifugal portion of the propeller blade 2. Therefore, a high shaft torque can be obtained. Since the rotational resistance is low, the rotational noise is quiet and suitable for wind turbines and water turbines for wind power generators.

  FIG. 12 is a front view of the propeller showing the seventh embodiment. The same parts as those in the previous example are denoted by the same reference numerals and description thereof is omitted. The seventh embodiment is for a windmill in which the rear surface in FIG. 3 is a front view and the front part of rotation of the propeller blade 2 is inclined in front of the inclined boundary line 2e.

When wind is received in front of the propeller blade 2 when used in a windmill, the wind is received from the front on the inclined front surface 2g having a pitch angle at the front portion of the rotation of the propeller blade 2 relative to the inclined boundary line 2e, and rotates in the rotation direction. .
In this case, the width of the flat blade root portion is wide, but the wind flow impinges upon the rotation is diffused in the centrifugal direction with rotation, so that it does not become a burden of rotation.

  Along with the rotation, the wind flow diffused in the rotational centrifugal direction of the propeller blade 2 is suppressed by the blade tip inclined portion 2b, and gathered on the inclined front surface 2g having a pitch angle at a portion ahead of the inclined boundary 2e. As a result, the rotational force of the propeller 1 is increased.

  In addition, the inclined front surface 2g having a pitch angle at the front portion of rotation relative to the inclined boundary line 2e is inclined in the front direction at the front edge of the front end 2c in FIG. The airflow hitting the inclined front surface 2g from the front increases the air density in order to increase the air density, and the propeller blade 2 is pushed in the pre-rotation direction, which has become a negative pressure for comparison, and the rotational force is increased.

  As the propeller blade 2 rotates, the wind flow escapes toward the tip of the inclined boundary line 2e and pushes the propeller blade 2 in the rotation direction. The bent base line 2a is located in the centrifugal portion of the propeller blade 2. Therefore, high shaft torque can be obtained. Since the rotational resistance is low, the rotational noise is quiet and suitable for wind turbines and water turbines for wind power generators.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed in design according to the purpose. A bent base line 2a and an inclined boundary line 2e in the drawing indicate a section, do not indicate a corner state of a mountain or a valley, and can be a gentle curved surface. Of course, the chord length of the blade tip portion of the propeller blade 2 can be made larger than the chord length of the blade root portion.

  The propeller 1 is used in propellers, pumps, ventilation fans, air conditioning fans, air cooling fans, wind turbines, and the like.

It is a rear view of the propeller which concerns on this invention. It is a top view in FIG. 6 is a plan view of a propeller showing Example 2. FIG. It is a top view in FIG. 6 is a rear view of a propeller illustrating Example 3. FIG. It is a top view in FIG. 10 is a rear view of a propeller showing Example 4. FIG. It is a top view in FIG. FIG. 10 is a rear view of a propeller showing Example 5. FIG. 10 is a plan view of the propeller in FIG. 9. 10 is a front view of a propeller showing Example 6. FIG. 10 is a front view of a propeller showing Example 7. FIG.

Explanation of symbols

1 propeller,
1a Boss part,
2 propeller wings,
2a Bent base line,
2b Blade tip slope,
2c Front end of rotation,
2d Rear end of rotation,
2e inclined boundary line,
2f inclined back,
2g Inclined front.
3 Propeller shaft

Claims (4)

It is a propeller rotated by a prime mover, and a bending base line is set with an equal distance of rotation radius so as to connect the front edge of the front end of rotation on both sides of the back of the propeller blade and the end edge of the rear end of rotation. The tip of the blade is tapered and the blade tip slope is set, the slope boundary is set from the tip of the front end to the rear end of the blade root, and the tip of the blade is set behind the slope boundary. The inclined back surface is inclined backward with respect to the inclined boundary line to form a pitch angle with respect to the relative flow in the pre-rotation direction, and the wing tip inclined portion has a bent base line at the front edge portion of the rotation. A propeller characterized by being curved and inclined backward as a base point. It is a propeller rotated by a prime mover, and a bending base line is set with an equal distance of rotation radius so as to connect the front edge of the front end of rotation on both sides of the back of the propeller blade and the end edge of the rear end of rotation. The tip is tapered and the blade tip slope is set. The slope boundary is set from the tip of the rear end of the rotation toward the front end of the blade root. Is set, and the inclined back surface is inclined with respect to the front edge of the bent base line in the front direction to form a pitch angle with respect to the relative flow in the pre-rotation direction. A propeller characterized in that the front edge portion of the rotation is curved and inclined in the backward direction with the bent base line as a base point. A bending base line is set with equal turning radii so as to connect the front edge of both front and rear rotation edges on the front side of the propeller blade, and the blade tip tapers from the bending base line. In this way, a blade tip inclined portion is formed, an inclined boundary line is set from the tip end of the front end of the rotation toward the rear end of the rotation of the blade root, and the inclination set to the rotation rear portion from the inclined boundary line. The front surface is inclined rearward to form a pitch angle with respect to the relative flow from the front direction, and the blade tip inclined portion is curved and inclined in the front direction with the front edge portion of the rotation as a base point of the bent base line. Propeller characterized by that. A bending base line is set with equal turning radii so as to connect the front edge of rotation on both sides of the front side of the propeller blade and the rear edge of the rotation side, and the blade tip tapers from the bending inclination base line. Thus, a blade tip inclined portion is formed, an inclined boundary line is set from the tip of the rear end of the rotation toward the front end of the blade root, and the inclination set to the front portion of the rotation from the inclined boundary line. The front surface is inclined toward the front, and a pitch angle is formed with respect to the relative flow from the front direction. The blade tip inclined portion is curved and inclined in the front direction with the front edge portion of the rotation as the base point of bending. Propeller characterized by being made.

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