JP5925997B2 - Blade of rotor for fluid equipment - Google Patents

Description

  The present invention relates to a blade for a fluid device rotor, and more particularly to a blade for a fluid device, wherein the blade has a large blade thickness, excellent rigidity, and allows fluid on the back surface of the blade to flow forward at a high speed. Related to the blade.

2. Description of the Related Art Conventionally, rotor blades used in propulsion devices, blowers, and the like are thin overall, and the fluid extrusion surface is twisted with respect to the rotational direction, and cavitation tends to occur at the blade root portion during rotation.
Moreover, since it is twisted as a whole, it is costly to produce accuracy during manufacturing. Examples of blades that do not easily cause cavitation are described in Patent Documents 1 and 2.

JP 2007-125914 A JP 2007-077652 A

The blades of the conventional rotor are configured to extrude a fluid from the front, require a large amount of power, and require a relatively large area of the extrusion surface.
In addition, in order to provide an angle of attack, three-dimensional solid formation is accompanied by design difficulties and increases the manufacturing cost burden.
The present invention provides a fluid device rotor that has a very simple blade shape, excellent rigidity, no cavitation, and excellent fluid discharge function with small power using the change in fluid pressure on the blade surface. A blade is provided.

According to the present invention, when rotating, a high-speed flow is generated on the back surface rather than the front surface of the blade, and the fluid on the back surface of the blade is caused to flow in the front front direction by utilizing a difference in fluid pressure generated thereby. Is related to the blade.
The specific contents of the present invention are as follows.

(1) In the lift type blade of a fluid device rotor in which a plurality of lift type blades facing the radial direction are provided on the peripheral surface of the hub, the front is vertical when viewed from the side with the blade tip of the lift type blade facing upward. The back surface is gradually inclined in the front direction from the blade root to the blade tip, the blade thickness is gradually decreased from the blade tip to the blade tip, and the front surface in plan view is a flat surface from the leading edge to the trailing edge. The maximum blade thickness near the leading edge in the chord length direction is approximately the same as the chord length of the portion at the blade root, and in the maximum chord length range from 15% to 25% of the chord length of the portion, and thinned convex curved trailing edge, by the Coanda effect at the time of rotation, the fluid velocity flowing along the back to the front front direction, and faster than the flow rate accompany the front, fluid passing from the back to the front forward Accordingly, the fluid, characterized in that to obtain a fluid delivery force Dexterity rotor blade.

(2) The blade is chamfered from the back toward the front blade tip from the back, and the blade has a convex convex tip so that high-speed fluid due to the Coanda effect generated on the back passes in the front front direction . The blade of the rotor for fluidic devices according to claim 1.

(3) In a plan view in which the blade tip of the blade is in an upward state, the front surface has an angle of attack inclined forward from the front edge to the rear edge with respect to the rotational direction. 2) A blade of a rotor for a fluid device described in 2).

(4) In a side view of the blade with the blade tip facing upward, the front surface is vertical from the blade root to the blade tip, and the back surface is gradually inclined forward from the blade root to the blade tip. The wing tip from the chord length part is a slanted projecting part that projects sharply upward in the front diagonal direction, the front is a straight surface from the maximum chord length part to the wing tip, and the back is the wing tip from the maximum chord length part to the wing The blade tip convex curved surface that bulges outward greatly toward the end, and gradually thinned from the thick leading edge to the trailing edge, according to any one of (1) to (3) Blade of rotor for fluid equipment.

  According to the present invention, the following effects can be obtained.

In the rotor blade described in (1), the front surface is a flat surface, and the back surface is the maximum chord length portion, the maximum blade thickness of the portion near the leading edge in the chord length direction is 15% to 25% of the chord length, As the curved surface has a thin trailing edge, the length in the chord length direction on the back side is longer than that on the front side, and the speed of fluid flowing in the front direction along the back side is higher than that on the front side when rotating. A difference occurs in the fluid pressure.
The high velocity flow along the chord direction on the back surface flows from the trailing edge to the front front direction along the curved surface of the back surface due to the Coanda effect, so that the fluid is pushed back without pushing the fluid in front of the blade. Can be sent forward from the front.
Since the fluid flows due to the difference in fluid pressure between the front surface and the back surface of the blade, no power is required for extrusion at the front surface of the blade, so that a large flow can be achieved with small power.

In the blade described in (2), the blade tip portion on the back surface is chamfered from the back surface to the blade tip on the front surface, and the tip is a convex curved surface. Since the chord length of the distant part is large, the fluid flows efficiently.

In the blade described in (3) above, the front surface is inclined in the front direction from the front edge to the rear edge with respect to the rotation direction in a plan view with the blade tip facing upward. Or when it receives a water current, it can be used as a windmill or a watermill.

In the blade described in (4), the front surface is vertical from the blade root to the blade tip in a side view of the blade with the blade tip facing upward, and the back surface is gradually in the front direction from the blade root to the blade tip. The wing tip from the maximum chord length part is a slant projecting part that protrudes diagonally upward, and the front surface is a straight surface from the chord length part to the wing tip, and the back surface is from the maximum chord length part. Since the blade tip convex curved surface that bulges outward outward from the front blade tip, the flowing water that moves along the rear surface moves toward the blade tip during rotation and slides along the convex curve in front of the front. Flow in the direction.

It is a front view of the blade of the rotor of the present invention. FIG. 2 is an enlarged cross-sectional plan view taken along line II-II in FIG. 1. It is a side view of the fluid rotary wheel in FIG. FIG. 4 is an enlarged cross-sectional plan view taken along line IV-IV in FIG. 1. It is a schematic diagram which shows the state of the fluid produced by the back surface of a braid | blade. It is a side view of Example 2 of the blade of the present invention. FIG. 7 is a transverse plan view of a maximum chord length portion in FIG. 6. It is a side view of Example 3 of the blade of the present invention. It is a top view of the braid | blade in FIG.

  Embodiments of the present invention will be described with reference to the drawings.

A fluid device rotor 1 (hereinafter simply referred to as a rotor) shown in FIG. 1 is formed by fixing a plurality of (two in the drawing) blades 3 and 3 facing the radial direction on the peripheral surface of a hub 2. Each blade 3 has a chord length that gradually increases from the blade root toward the blade tip in a front view with the blade tip facing upward, and then tapers from the maximum chord length portion 3C to the blade tip. Sharp.

As shown in FIG. 2, the front surface 3D of the blade 3 is a flat surface orthogonal to the center line S of the rotor shaft 4 from the front edge 3A in the rotational direction to the rear edge 3B.
The cross section of the front edge 3A is arcuate, and the back surface 3F has a maximum blade thickness portion 3E in the chord direction and an intermediate blade thickness near the front edge 3A, and a curved surface toward the rear edge 3B.

  The thickness of the maximum blade thickness portion 3E is 15% to 25%, preferably about 23% of the maximum chord length. If it is 15% or less, the ratio of the width between the front surface 3D and the back surface 3F is small, and an effective high-speed flow is unlikely to occur on the back surface 3F. On the other hand, if it is 25% or more, the resistance during rotation becomes large, and the rotation efficiency decreases.

  As the blade 3 rotates, the fluid flowing on the back surface 3F from the front edge 3A to the rear edge 3B becomes faster than the fluid along the front surface 3D, and flows at high speed in the direction indicated by the arrow b in FIG. 2 due to the Coanda effect. .

  As shown in FIG. 3, the side view of the blade 3 is as follows. From the blade root to the blade tip, the front surface 3D is orthogonal to the rotation center line S, and the back surface 3F is a blade tip having a large thickness. It gradually becomes thinner in the front direction. The maximum thickness of the blade root is approximately the same as the chord length of the blade root.

Further, as shown in FIG. 3, the blade tip portion on the back surface 3F is a convex curved surface 3G of the blade tip that is chamfered from the back surface toward the front blade tip and is curved in the longitudinal direction and the front 3D direction. Therefore, when the rotor 1 rotates, the fluid that moves the back surface 3F of the blade 3 in the direction of the blade tip flows in the direction indicated by the arrow a along the convex curved surface 3G of the blade tip.

  FIG. 4 is an enlarged plan view taken along the line IV-IV in FIG. The thickness of the maximum blade thickness portion 3E is about twice the blade thickness in the maximum chord length portion 3C shown in FIG. 1, and the chord length is smaller than that in the maximum chord length portion 3C.

  Therefore, the convex curvature of the back surface 3F in the chord length direction is large, and the fluid flowing on the back surface 3F from the front edge 3A to the rear edge 3B flows in the front inner direction, that is, in the direction indicated by the c arrow, The line S will be approached.

  FIG. 5 is a schematic diagram showing a fluid state when the rotor 1 shown in FIG. 1 rotates. As the rotor 1 rotates, the relative flow Y impinging on the leading edge 3A of the blade 3 is increased in speed on the back surface 3F from the leading edge 3A beyond the maximum blade thickness portion 3E, and is indicated by a high-speed arrow b toward the trailing edge 3B. It becomes a flow. Due to the difference in the radius of rotation at each part of the blade 3, the speed of the b arrow flow is higher than the c arrow flow approaching the rotation center line S.

When the rotor 1 rotates, the fluid that slides at high speed on the blade root portion of the back surface 3F of the blade 3 from the leading edge 3A to the trailing edge 3B becomes a c-direction flow, and approaches the center line S.
The hatched portion between the flow indicated by the arrow b and the flow indicated by the arrow c is a high-speed flow, is circular when viewed from the front, and is faster on the outer side than on the inner side.

  In high-speed flow, the fluid pressure decreases because the density of the fluid decreases. In FIG. 5, the normal pressure flow indicated by the arrow X from the surroundings merges with the fluid band indicated by the slanted line between b and c which are low pressure due to the difference in fluid pressure, and pushes in the direction of the center line S. Flows forward from the front 3D.

Therefore, even if the front surface 3D of the blade 3 is a flat surface orthogonal to the center line S and the fluid cannot be extruded during rotation, a large amount of fluid flowing along the convex curved surface 3G of the back surface 3F of the blade 3 can be obtained. The fluid can be caused to flow in the forward direction of the front surface 3D by the difference in fluid pressure.

  Thus, the blade 3 of the rotor 1 is suitable for a propulsion device, a blower, or the like that drives the rotor shaft 4 with power. In addition, since the blade of the conventional type has a thin blade thickness, when the wind stops, an eddy current is generated on the front side and stalls. However, since the blade 3 of the present invention has a large blade thickness at the front edge 3A portion, When it stops, the flow velocity on the front 3D side rises and does not stall. When it receives wind again, it accelerates and rotates.

FIG. 6 is a side view showing a second embodiment of the rotor 1, and FIG. 7 is a transverse plan view of the maximum chord length portion 3C.
The same members as those of the previous example are denoted by the same reference numerals and description thereof is omitted.

  In Example 2, in the front surface 3D of the blade 3, the blade root portion was parallel to the rotation direction, and the maximum chord length portion 3C portion had an angle of attack θ of 3 degrees to 7 degrees with respect to the rotation direction. As a thing.

  As the rotor 1 rotates, the relative flow Y that hits the leading edge 3A of the blade 3 is pushed by the maximum chord length portion 3C of the front surface 3D having an angle of attack θ, and becomes a flow indicated by an arrow d. This d-arrow flow is a normal pressure flow, but is faster than the relative flow Y. Since the blade root portion does not have an angle of attack, the flow velocity does not change and cavitation does not occur.

  As shown in FIG. 6, the maximum chord length portion 3C is inclined in the direction of the center line S of the rotation shaft 4 with respect to the vertical, so that the fluid pushed by the maximum chord length portion 3C is inclined in the center direction. Extruded. As a result, the flow indicated by the arrows b and c in FIG. 5 flows while enclosing the flow indicated by the arrow d, and flows from the outer area so that the flow indicated by the arrow X wraps, resulting in a large flow.

In FIG. 7, the angle of attack θ of the front surface 3D of the blade 3 is inclined toward the front direction from the front edge 3A to the rear edge 3B with respect to the rotation direction.
In FIG. 7, when the fluid is received from the direction of the back surface 3F, the blade 3 rotates, so that it can be used as a water wheel or a windmill.

  Since the blade of the conventional type has a thin blade thickness, when the wind stops, an eddy current is generated on the front side and stalls. However, the blade 3 of the present invention has a maximum blade thickness at the front edge 3A portion, When it stops, the flow velocity on the front side will not rise and stall, and if it receives wind again, it will accelerate and rotate.

FIG. 8 is a side view showing the third embodiment of the rotor 1, and FIG. 9 is an enlarged plan view of the same. The same members as those in the previous example are denoted by the same reference numerals, and description thereof is omitted.
In this embodiment, the portion from the maximum chord length portion 3C to the blade tip at the blade tip of the blade 3 with the blade tip facing upward is defined as a slant projecting portion 31 that projects obliquely upward at the front.

The front surface 31D of the oblique projecting portion 31 is a straight surface inclined by 35 to 45 degrees with respect to the vertical in a side view, and the oblique projecting portion 31 is gradually thinner and obliquely projected from the maximum chord length portion 3C to the blade tip. The rear surface 31F of the portion 31 is a convex curved surface 31F whose middle is swollen from the maximum chord length portion 3C toward the blade tip.

In FIG. 8, when the blade 3 rotates, the peripheral speed of the blade tip is faster than that of the blade root, so that the velocity of the fluid flowing along the blade tip becomes faster than the velocity of the fluid flowing along the blade root. Since the fluid pressure decreases, the fluid moves from the blade root toward the blade tip, and in the front surface 3D, it slides on the front surface 31D of the oblique protrusion 31 and flows in the direction indicated by the arrow e. The fluid along the back. 3F, the rear convex surface 31F of the swash protrusions 31 sliding into the tip direction, flows into the e direction of the arrow.

  As a result, as the blade 3 rotates, the fluid that strikes the back surface 3F moves in the direction of the blade tip, and the forward e-arrow direction in the front surface 3D along the convex curved surface 31F on the back surface of the oblique projection 31 To flow at high speed.

  In this e-arrow flow, since the back surface 31F of the oblique protrusion 31 is at the farthest position from the rotation axis 4, the rotational peripheral speed is maximum, and the arrow b and c in FIGS. It is faster than the flow, and these are enclosed in an annulus from the outside to absorb the ambient normal pressure flow and increase the flow velocity.

  In FIG. 6, when a fluid hits the blade 3 from the back surface 3F direction, it flows at high speed in the b and c directions, and the blade 3 rotates in the direction of the leading edge 3A by the reaction. Along with the rotation, the relative flow also flows at high speeds in the b and c directions, and the rotation speed of the blade 3 increases. Therefore, it can be preferably used for wind turbines and water turbines.

As described in detail above, the rotor blade of the present invention has a simple structure and is excellent in rigidity and flow feeding function. Therefore, it can be used in airplanes, ship propulsion devices, air blowers, water pumps, etc. It can be used effectively.
It can also be used for wind turbines and water turbines that rotate by receiving fluid.

  Since the structure of the blade is simple and a high-speed flow can flow, the blade can be effectively used for a propulsion device, a blower, a water supply, or a water wheel or a windmill that rotates by receiving fluid on the back surface.

1. Rotor 2. Hub 3. Lift type blade 3A. Leading edge 3B. Trailing edge 3C. Maximum chord length 3D. Front 3E. Maximum blade thickness 3F. Back 3G. Wing tip convex curved surface
31.Slant protrusion
31D. Front of oblique projection
31F. Convex surface 4. Rotor shaft

Claims (4)

In the lift type blade of a fluid equipment rotor, which has a plurality of lift type blades facing the radial direction on the peripheral surface of the hub, the front is vertical and the back in a side view with the blade end of the lift type blade facing upward Is gradually inclined in the front direction from the blade root to the blade tip, the blade thickness is gradually decreased from the blade tip to the blade tip, and the front surface in a plan view is a flat surface from the leading edge to the trailing edge, and the back surface is a string The maximum blade thickness near the leading edge in the longitudinal direction is approximately the same as the chord length of the portion at the blade root, and the maximum chord length is within the range of 15% to 25% of the chord length of the portion. and thinned convex surface, the Coanda effect at the time of rotation, the fluid velocity flowing along the back to the front front direction, and faster than the flow rate accompany the front, by the fluid passing from the back to the front forward, fluid b fluid device being characterized in that to obtain the transmission power Blade. The blade has a blade tip portion on the back surface that is chamfered from the back surface to the blade tip on the front surface, and has a convex tip curved surface so that fluid due to the Coanda effect generated on the back surface passes forward. The blade of the rotor for fluidic devices according to claim 1. 2. The planar view in which the blade tip is in an upward state, the front surface has an angle of attack inclined forward from the front edge to the rear edge with respect to the rotational direction. 3. A blade of a rotor for a fluid device according to 2. In side view of the blade with the blade tip facing upward, the front is vertical from the blade root to the blade tip, and the back is gradually inclined forward from the blade root to the blade tip. The blade tip is a slanted projecting portion that projects sharply upward in the front diagonal direction, the front surface is a straight surface from the maximum chord length portion to the wing tip, and the back surface is from the maximum chord length portion to the wing tip. 4. The fluid according to claim 1, wherein the fluid is a convex curved surface that bulges outward in the middle and is gradually thinned from the thick leading edge to the trailing edge. Blade of equipment rotor.

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