JP2009250225A - Moving blade and axial flow blower using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial flow blower capable of blowing air in both of normal/reverse directions to achieve efficient air blowing. <P>SOLUTION: A blade cross section has a basic shape in which a blade cross sectional shape is provided, the skeleton line warps to a negative pressure surface side, the vertex position exists up to 50% in relation to a blade chord length from a front edge, the front edge has a circular-arc shape, thickness is gradually increased from the front edge, maximum thickness is provided at a vertex of warpage and the thickness is gradually thinned toward a rear edge. The skeleton line has a shape warping to a positive pressure surface side on the front edge side in the vicinity of a rear edge. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an axial blower that is installed on a ceiling of an automobile road tunnel and ventilates the inside of the tunnel by a pressure increase caused by a jet.

  The structure of the conventional axial blower is shown in FIGS.

  In the axial blower shown in FIG. 8, a motor 102 is housed in a cylindrical casing 101, and an impeller 103 is attached to the shaft of the motor 102. In the case of FIG. 8, the motor 102 is a single-axis motor, and the impeller 103 is one-stage mounted. In the case of FIG. 9, the motor 102 is a double-axis motor, and the impeller has a two-stage configuration by attaching impellers 103 a and 103 b to the respective shafts (Patent Document 1).

This type of axial blower is often required to have the same performance in the forward and reverse directions. FIG. 10 shows an example of a cross-sectional shape of a moving blade having the same performance in both the forward direction and the reverse direction in a conventional one-stage blade axial fan. The moving blade 201 is a point-symmetric airfoil in which the coordinates of the abdominal side 202a and the back side 202b of the moving blade are point-symmetric with respect to the center of gravity 203 of the moving blade. FIG. 8 is a schematic view showing a state in which the moving blades 201 are attached to an axial blower. The moving blades 201 are attached radially to the impeller 103. Since the moving blade 201 is point-symmetric, by switching the rotation direction of the motor 102, it is possible to achieve the same performance in both the forward direction and the reverse direction. FIG. 11 shows an example of a cross-sectional shape of a moving blade having the same performance in both the forward and reverse directions in a conventional two-stage blade axial fan. The rotor blades 211a and 211b have a so-called airfoil cross-sectional shape having a pressure surface 212a and a suction surface 212b. FIG. 9 is a schematic view showing a state in which the impellers 103a and 103b are attached to an axial blower, and moving blades 211a and 211b are radially attached to the impellers 103a and 103b. Since the moving blades 211a and 211b have the same number and the mounting angles are different by 180 degrees, it is possible to achieve the same performance in both the forward direction and the reverse direction by switching the rotation direction of the motor 102. is there.
JP-A-9-287594 Japanese Patent No. 2997257

  In the axial blower provided with the two-stage impeller as shown in FIG. 9 and FIG. 11, the shape of the moving blade is designed so that the work by the moving blade on the upstream side with respect to the wind direction is efficiently performed, and the downstream side The rotor blades rotate in the direction opposite to the efficient rotation direction. Therefore, the moving blades on the downstream side (second-stage moving blades) play an auxiliary role in generating the air volume, but cause a decrease in blower efficiency.

  In addition, in an axial blower in which a single-stage impeller as shown in FIGS. 8 and 10 is provided and the cross-sectional shape of the moving blade is point-symmetric with respect to the center of gravity is the same regardless of whether it is forward or reverse. Has performance. However, it is difficult to find a shape with a good lift-drag ratio compared to the airfoil cross-sectional shape.

  An object of the present invention is to solve the above-mentioned problems and to provide an axial fan that efficiently blows air in both the forward and reverse directions.

  In order to solve the above-mentioned problem, the moving blade of the axial blower of the present invention according to claim 1 has an airfoil cross-sectional shape, its skeleton line is warped on the suction surface side, and its apex position is a leading edge. More than 50% of the chord length, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually toward the trailing edge In the airfoil cross section of the basic shape with a reduced thickness, the skeleton line is warped to the pressure surface side on the front edge side in the vicinity of the rear edge.

  The rotor blade of the axial flow fan of the present invention according to claim 2 has an airfoil cross-sectional shape, its skeleton line is warped toward the suction surface side, and its apex position is 50 with respect to the chord length from the leading edge. %, The leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section, the airfoil section has a shape having an arc-shaped convex portion on the pressure surface side near the trailing edge.

  The moving blade of the axial blower of the present invention according to claim 3 has an airfoil cross-sectional shape, its skeleton line is warped toward the suction surface side, and its apex position is 50 with respect to the chord length from the leading edge. %, The leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section, the airfoil has a shape having an arc-shaped convex portion on the suction surface side near the trailing edge.

  The moving blade of the axial blower of the present invention according to claim 4 has an airfoil cross-sectional shape, its skeleton line is warped toward the suction side, and its apex position is 50 with respect to the chord length from the leading edge. %, The leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section, the airfoil section has a shape having arc-shaped convex portions on both the pressure surface side and the suction surface side near the trailing edge.

  The moving blade of the axial blower of the present invention according to claim 5 has an airfoil cross-sectional shape, its skeleton line is warped toward the suction surface side, and its apex position is 50 with respect to the chord length from the leading edge. %, The leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section, the skeleton line is warped on the pressure surface side on the front edge side in the vicinity of the trailing edge, and has a shape having an arc-shaped convex portion on the pressure surface side in the vicinity of the trailing edge. .

  The moving blade of the axial flow fan of the present invention according to claim 6 has an airfoil cross-sectional shape, the skeleton line is warped toward the suction surface side, and the apex position is 50 with respect to the chord length from the leading edge. %, The leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section, the skeleton line is warped on the pressure surface side on the front edge side in the vicinity of the trailing edge, and has a shape having an arc-shaped convex portion on the suction surface side in the vicinity of the trailing edge. .

  The moving blade of the axial blower of the present invention according to claim 7 has an airfoil cross-sectional shape, its skeleton line is warped toward the suction surface side, and its apex position is 50 with respect to the chord length from the leading edge. %, The leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section, the skeleton line is warped on the pressure surface side on the front edge side near the trailing edge, and the shape has arcuate convex portions on both the pressure surface side and suction surface side near the trailing edge. It is a feature.

  An axial blower according to an eighth aspect of the present invention is driven by an electric motor capable of normal rotation and reverse rotation, and includes one stage of an impeller having a moving blade according to any one of the first to seventh aspects. By switching the direction, it is possible to blow in the forward direction and the reverse direction.

  The axial flow fan of the present invention according to claim 9 is driven by an electric motor capable of normal rotation and reverse rotation, and includes two stages of impellers having moving blades according to any one of claims 1 to 7, each blade of which The moving blades of the vehicle are attached so that the rear edges face each other, and can be blown in the forward direction and the reverse direction by switching the rotation direction.

  An axial fan according to a tenth aspect of the present invention is driven by an electric motor capable of normal rotation and reverse rotation, and includes two stages of impellers having the moving blade according to any one of claims 1 to 7, and the moving blade is All have the same shape, the mounting angle of the moving blades attached to each impeller is 180 degrees different, and it is possible to blow with the same performance in the forward direction and the reverse direction by switching the rotation direction of the impeller To do.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to implement | achieve efficient ventilation in the axial flow fan which needs ventilation of the forward / reverse direction.

  The rotor blade of the axial flow fan according to the first embodiment of the present invention has an airfoil cross-sectional shape, and its skeleton line is warped toward the suction side, and its apex position is relative to the chord length from the leading edge. Basically, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section of the shape, the skeleton line is warped to the pressure surface side on the front edge side in the vicinity of the rear edge. According to the present embodiment, since the flow can flow at an appropriate angle of attack from the leading edge during forward rotation, it is possible to provide a moving blade having a high lift and a low drag, that is, a good lift-drag ratio. On the other hand, at the time of reverse rotation, the flow will flow from the rear edge, but since the skeleton line is warped on the pressure side at the time of forward rotation on the front edge side near the rear edge, the lift coefficient at the time of reverse rotation is It can be improved. In addition, since the warpage is only in the vicinity of the trailing edge, it is possible to suppress performance degradation during forward rotation as much as possible.

  The rotor blade of the axial blower according to the second embodiment of the present invention has an airfoil cross-sectional shape, its skeleton line is warped toward the suction side, and its apex position is relative to the chord length from the leading edge. Basically, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section having a shape, the airfoil section has a shape having an arc-shaped convex portion on the pressure surface side near the trailing edge. According to the present embodiment, at the time of reverse rotation, the flow flows from the rear edge, but since the shape has an arc-shaped convex part on the pressure surface side near the rear edge, the angle of attack at the time of reverse rotation is When it is relatively small, the flow inflow from the trailing edge becomes smooth, and the lift coefficient can be improved. Moreover, since the convex part is only in the vicinity of the trailing edge, it is possible to suppress a decrease in performance during normal rotation as much as possible.

  The rotor blade of the axial flow fan according to the third embodiment of the present invention has an airfoil cross-sectional shape, and its skeleton line is warped toward the suction surface side, and its apex position is relative to the chord length from the leading edge. Basically, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. The shape of the airfoil cross-section has a shape having an arc-shaped convex portion on the suction surface side near the trailing edge. According to this embodiment, at the time of reverse rotation, the flow flows from the trailing edge, but since the shape has an arc-shaped convex part on the suction surface side near the trailing edge, the angle of attack at the time of reverse rotation is When it is relatively large, the flow inflow from the trailing edge becomes smooth, and the lift coefficient can be improved. Moreover, since the convex part is only in the vicinity of the trailing edge, it is possible to suppress a decrease in performance during normal rotation as much as possible.

  The rotor blade of the axial flow fan according to the fourth embodiment of the present invention has an airfoil cross-sectional shape, and its skeleton line is warped toward the suction side, and its apex position is relative to the chord length from the leading edge. Basically, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section having a shape, the airfoil section has a shape having arc-shaped convex portions on both the pressure surface side and the suction surface side near the trailing edge. According to the present embodiment, at the time of reverse rotation, the flow flows from the rear edge, but since the shape has arcuate convex portions on both the pressure surface side and the suction surface side near the rear edge, Even if the angle of attack is large or small at the time of reverse rotation, the inflow of the flow from the trailing edge becomes smooth, and the lift coefficient can be improved. Moreover, since the convex part is only in the vicinity of the trailing edge, it is possible to suppress a decrease in performance during normal rotation as much as possible.

  The rotor blade of the axial flow fan according to the fifth embodiment of the present invention has an airfoil cross-sectional shape, and its skeleton line is warped toward the suction side, and its apex position is relative to the chord length from the leading edge. Basically, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the shape of the airfoil section, the skeleton line is warped on the pressure surface side on the front edge side in the vicinity of the rear edge, and the shape has an arc-shaped convex part on the pressure surface side in the vicinity of the rear edge It is. According to the present embodiment, at the time of reverse rotation, the flow flows from the rear edge, but the skeleton line is warped on the pressure surface side on the front edge side near the rear edge, and on the pressure surface side near the rear edge. Since it has a shape having an arc-shaped convex portion, when the angle of attack is relatively small during reverse rotation, the flow inflow from the trailing edge becomes smooth and the lift coefficient can be improved. Moreover, since the curvature and the convex part are only in the vicinity of the trailing edge, it is possible to suppress a decrease in performance in forward rotation as much as possible.

  The rotor blade of the axial flow fan according to the sixth embodiment of the present invention has an airfoil cross-sectional shape, its skeleton line is warped toward the suction surface side, and its apex position is relative to the chord length from the leading edge. Basically, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the shape of the airfoil section, the skeleton line is warped on the pressure surface side on the front edge side in the vicinity of the rear edge, and the shape has an arc-shaped convex part on the suction surface side in the vicinity of the rear edge It is. According to the present embodiment, at the time of reverse rotation, the flow flows from the rear edge, but the skeleton line is warped on the pressure surface side on the front edge side near the rear edge, and on the suction surface side near the rear edge. Since it has a shape having an arc-shaped convex portion, when the angle of attack is relatively large at the time of reverse rotation, the inflow of the flow from the trailing edge becomes smooth, and the lift coefficient can be improved. Moreover, since the curvature and the convex part are only in the vicinity of the trailing edge, it is possible to suppress a decrease in performance in forward rotation as much as possible.

  The rotor blade of the axial flow fan according to the seventh embodiment of the present invention has an airfoil cross-sectional shape, and its skeleton line is warped toward the suction side, and its apex position is relative to the chord length from the leading edge. Basically, the leading edge has an arc shape, the thickness gradually increases from the leading edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the airfoil cross section of the shape, the skeleton line is warped to the pressure surface side on the front edge side near the trailing edge, and the shape has arcuate convex portions on both the pressure surface side and the suction surface side near the trailing edge. It is characterized by this. According to the present embodiment, at the time of reverse rotation, the flow flows in from the rear edge, but the skeleton line is warped on the pressure surface side on the front edge side near the rear edge, and the pressure surface side near the rear edge and Since it has a shape with arc-shaped convex portions on both sides of the suction surface side, flow inflow from the trailing edge is smooth even when the angle of attack is large or small during reverse rotation, and the lift coefficient can be improved. I can do it. Moreover, since the curvature and the convex part are only in the vicinity of the trailing edge, it is possible to suppress a decrease in performance in forward rotation as much as possible.

  An axial blower according to an eighth embodiment of the present invention is driven by an electric motor capable of normal rotation and reverse rotation, and has one stage of an impeller having moving blades according to any one of claims 1 to 7, By switching the rotation direction, it is possible to blow air in the forward direction and the reverse direction. According to the present embodiment, it is possible to provide an axial-flow fan of a moving blade having a good lift-drag ratio during normal rotation, and as described in the first to seventh embodiments, the lift coefficient during reverse rotation It is possible to provide an axial blower that improves the above.

  An axial blower according to a ninth embodiment of the present invention is driven by an electric motor capable of normal rotation and reverse rotation, and includes two stages of impellers having moving blades according to any one of claims 1 to 7, each of which The impeller blades are attached so that their rear edges face each other, and can be blown in the forward direction and the reverse direction by switching the rotation direction. According to the present embodiment, the moving blade of the first stage impeller has a good lift-drag ratio, and the second stage impeller flows from the trailing edge. Even if it is a case where it flows in from a rear edge as described in the Example of -7, the axial-flow fan which improved the lift coefficient can be provided. Moreover, the same effect can be acquired even if it is a forward direction or a reverse direction.

  An axial blower according to a tenth embodiment of the present invention is driven by an electric motor capable of normal rotation and reverse rotation, and has two stages of impellers having moving blades according to any one of claims 1 to 7, All the blades have the same shape, the mounting angle of the moving blades attached to each impeller is 180 degrees different, and it is possible to blow the same performance in the forward direction and the reverse direction by switching the rotation direction of the impeller. It is a feature. According to the present embodiment, the moving blade of the first stage impeller has a good lift-drag ratio, and the second stage impeller flows from the trailing edge. Even if it is a case where it flows in from a rear edge as described in the Example of -7, the axial-flow fan which improved the lift coefficient can be provided. In addition, the same effect can be obtained regardless of whether it is forward rotation or reverse rotation, and the mounting angle of the first and second stage blades is 180 degrees different. An axial blower having the same performance in all the reverse directions can be provided.

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

Example 1
FIG. 1 shows a moving blade according to a first embodiment of the present invention. FIG. 1 shows a case of an axial blower having two-stage blades, where the moving blade 1a (FIG. 1a-1) is the first stage, and the moving blade 1b (FIG. 1b-1) is the moving blade of the second-stage impeller. It is. In the figure, a speed triangle (wind velocity vector diagram; FIGS. 1 a-2 and b-2) is also shown. The wind velocity vectors at the inlet (front edge) and the outlet (rear edge) of the first stage blade 1a are C1 and C2, respectively. In the figure, u is a peripheral speed vector of the impeller. Further, w1 and w2 are relative velocity vectors at the inlet and outlet of the moving blade 1a, and w∞1 is a vector average of w1 and w2. When evaluating a rotor blade of an axial-flow fan, it is generally assumed that a uniform flow of w∞1 hits a stationary blade 1a. In the case of the second stage moving blade 1b, the wind velocity vectors at the inlet (rear edge) and the outlet (front edge) are C2 and C3, respectively, and the relative velocity vectors at the inlet and outlet are w2 and w3, respectively. . w∞2 is a vector average of w2 and w3.

  As shown in FIG. 1, the skeleton lines of the rotor blades 1a and 1b are warped to the suction surface side, the apex positions thereof exist up to 50% of the chord length from the leading edge, and the leading edge has an arc shape. It has a so-called airfoil cross-sectional shape as a basic shape that gradually increases from the leading edge, has a maximum thickness at the top of the warp, and gradually decreases toward the trailing edge. In the vicinity of the rear edge, the skeleton line is warped to the pressure surface side. FIG. 11 shows a moving blade of a conventional two-stage blade axial fan. As described above, the rotor blades 211a and 211b have a so-called airfoil cross-sectional shape, and unlike FIG. 1, the skeleton line at the trailing edge does not warp on the pressure surface side.

  The inlet of the first stage moving blade 1a and the moving blade 211a flows at the angle of attack α1 and the wind speed w∞1. At the inlet (front edge), the flow is divided into the pressure surfaces 2a and 212a and the suction surfaces 2b and 212b. Since the basic shape of the moving blade 1a is a blade cross-sectional shape and the moving blade 211a is a so-called blade cross-sectional shape, the wind speed on the suction surface side is relatively faster than the wind speed on the pressure surface side, and the difference in static pressure Is generated, lift is generated from the pressure side toward the suction side, and the impeller pushes out air. Thereafter, the air flows into the inlets of the second stage moving blades 1b and 211b at the angle of attack α2 at the wind speed w∞2. The pressure surface 212d in the case of the conventional blade 211b has the same shape as the suction surface 212b of the first stage blade 211a, and the suction surface 212c becomes the pressure surface 212a of the first stage blade 211a. The static pressure difference between the positive pressure surface and the negative pressure surface generated in step 1 is less likely to occur. That is, since the inlet is the trailing edge of the airfoil cross section and warps toward the negative pressure surface 212c, the flow that has flowed into the negative pressure surface 212c is easy to peel off and efficient ventilation cannot be performed. On the other hand, in the case of FIG. 1, the inlet of the second stage moving blade 1b is warped toward the suction surface 2c (the pressure surface 2a side of the first stage blade 1a), so the flow to the suction surface 2c is smooth. Thus, it is possible to improve the efficiency of air blowing by the second stage moving blade 1b. Moreover, since the basic shape of the moving blades 1a and 1b is an airfoil cross section, the lift-drag ratio of the first-stage moving blade 1a is not greatly impaired.

(Example 2)
FIG. 2 shows a moving blade of a second embodiment of the present invention. FIG. 2 shows the case of an axial flow fan with two-stage blades as in FIG. 1, where the moving blade 1a is the first-stage blade and the moving blade 1b is the moving blade of the second-stage impeller. The rotor blades 1a and 1b have a so-called airfoil cross-sectional shape as a basic shape, as in the first embodiment. And in the vicinity of the rear edge, it has an arc-shaped convex part on the pressure surface 2a side.

  In the case of the conventional moving blade 211b of FIG. 11, since the inlet of the second-stage moving blade 211b is the trailing edge of the airfoil section and is sharp, as described above, the loss during inflow is large and efficient air blowing. I can't. In the case of FIG. 2, since there is an arc-shaped convex portion on the suction surface 2c side (the pressure surface 2a side of the first-stage moving blade 1a) of the inlet of the second-stage moving blade 1b, loss during inflow is suppressed. I can do it. In particular, this embodiment is effective when the angle of attack α2 of the second stage moving blade 1b is relatively small. Moreover, since the basic shape of the moving blades 1a and 1b is an airfoil cross section, the lift-drag ratio of the first-stage moving blade 1a is not greatly impaired.

(Example 3)
FIG. 3 shows a moving blade according to a third embodiment of the present invention. FIG. 3 shows the case of an axial flow fan with two-stage blades as in FIG. 1, where the moving blade 1a is the first-stage blade and the moving blade 1b is the moving blade of the second-stage impeller. The rotor blades 1a and 1b have a so-called airfoil cross-sectional shape as a basic shape, as in the first embodiment. And in the vicinity of the rear edge, it has an arc-shaped convex part on the suction surface 2b side.

  In the case of the conventional moving blade 211b of FIG. 11, since the inlet of the second-stage moving blade 211b is the trailing edge of the airfoil section and is sharp, as described above, the loss during inflow is large and efficient air blowing. I can't. In the case of FIG. 3, since there is an arc-shaped convex portion on the pressure surface 2d side (the suction surface 2b side of the first stage blade 1a) of the inlet of the second stage blade 1b, the loss during inflow is suppressed. I can do it. In particular, this embodiment is effective when the angle of attack α2 of the second stage moving blade 1b is relatively large. Moreover, since the basic shape of the moving blades 1a and 1b is an airfoil cross section, the lift-drag ratio of the first-stage moving blade 1a is not greatly impaired.

Example 4
FIG. 4 shows a moving blade according to a fourth embodiment of the present invention. FIG. 4 shows the case of an axial blower having two-stage blades as in FIG. 1, where the moving blade 1a is the first-stage blade and the moving blade 1b is the moving blade of the second-stage impeller. The rotor blades 1a and 1b have a so-called airfoil cross-sectional shape as a basic shape, as in the first embodiment. And in the vicinity of the rear edge, it has an arc-shaped convex part on the pressure surface 2a side and the suction surface 2b side.

  In the case of the conventional moving blade 211b of FIG. 11, since the inlet of the second-stage moving blade 211b is the trailing edge of the airfoil section and is sharp, as described above, the loss during inflow is large and efficient air blowing. I can't. In the case of FIG. 4, the pressure surface 2d side (the negative pressure surface 2b side of the first-stage moving blade 1a) and the negative pressure surface 2c side (the pressure surface 2a of the first-stage moving blade 1a) at the inlet of the second-stage moving blade 1b. (Side) has an arc-shaped convex portion, so that loss during inflow can be suppressed. In particular, in the present embodiment, it is effective whether the angle of attack α2 of the second stage blade 1b is large or small. Moreover, since the basic shape of the moving blades 1a and 1b is an airfoil cross section, the lift-drag ratio of the first-stage moving blade 1a is not greatly impaired.

(Examples 5-7)
5, 6 and 7 show the blades of the fifth, sixth and seventh embodiments of the present invention, respectively. In the case of FIG. 5, the effects of both the first and second embodiments can be obtained. In the case of FIG. 6, the effects of both the first and third embodiments can be obtained, and in the case of FIG. 7, the effects of both the first and fourth embodiments can be obtained.

  In the first to seventh embodiments, the two-stage moving blade has been described. However, the same effect can be obtained with a single-stage axial blower. That is, it is possible to provide a one-stage axial flow fan that can ensure a certain degree of reverse blowing performance while ensuring normal blowing performance.

  The present invention can be used for a blower, a pump, or the like that requires performance during forward rotation and reverse rotation.

Sectional view of moving blade of first embodiment of the present invention ((a-1) First-stage moving blade sectional view, (a-2) Same wind velocity vector diagram, (b-1) Second-stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view) Sectional view of moving blade of second embodiment of the present invention ((a-1) First-stage moving blade sectional view, (a-2) Same wind speed vector diagram, (b-1) Second-stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view) Sectional view of moving blade of third embodiment of the present invention ((a-1) First-stage moving blade sectional view, (a-2) Same wind speed vector diagram, (b-1) Second-stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view) Sectional view of moving blade of fourth embodiment of the present invention ((a-1) First-stage moving blade sectional view, (a-2) Same wind velocity vector diagram, (b-1) Second-stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view) Sectional view of moving blade of fifth embodiment of the present invention ((a-1) First stage moving blade sectional view, (a-2) Same wind speed vector diagram, (b-1) Second stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view) Sectional view of moving blade of sixth embodiment of the present invention ((a-1) First-stage moving blade sectional view, (a-2) Same wind speed vector diagram, (b-1) Second-stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view) Sectional view of moving blade of seventh embodiment of the present invention ((a-1) First-stage moving blade sectional view, (a-2) Same wind speed vector diagram, (b-1) Second-stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view) The figure which shows the axial-flow fan using the conventional 1 stage impeller. Cross section of a conventional blade with a point-symmetric cross section The figure which shows the axial-flow fan using the conventional 2-stage impeller Sectional view of moving blade of conventional two-stage axial flow fan ((a-1) First-stage moving blade sectional view, (a-2) Same wind speed vector diagram, (b-1) Second-stage moving blade Sectional view, (b-2) Same wind speed vector diagram, (c) A part enlarged view)

Explanation of symbols

1a Rotor blade (first stage)
1b Rotor blade (second stage)
2a Pressure surface (of the first stage moving blade) 2b Negative pressure surface (of the first stage moving blade) 2c Negative pressure surface (of the second stage moving blade) 2d Pressure surface (of the second stage moving blade) 101 Cylindrical casing 102 Motor 103 impeller 103a, 103b impeller 201 moving blade 211a moving blade (first stage)
211b Rotor blade (second stage)
212a Pressure surface (of the first stage blade) 212b Vacuum surface (of the first stage blade) 212c Vacuum surface (of the second stage blade) 212d Pressure surface (of the second stage blade) C1 (First stage blade) Wind speed vector C2 (at the inlet of the first stage blade and at the inlet of the second stage blade) C3 (at the outlet of the second stage blade) Wind speed vector w1 (at the inlet of the second stage blade) Relative velocity vector w2 (at the blade inlet) w2 (at the outlet of the first stage blade and the inlet of the second stage blade) Relative velocity vector w3 (at the outlet of the second stage blade) w∞1 Vector average (for w1, w2) w∞2 Vector average (for w2, w3) α1 Angle of attack (for first stage blade) α2 Angle of attack (for second stage blade)

Claims (10)

It has an airfoil cross-sectional shape, its skeletal line warps to the suction side, its apex position exists up to 50% of the chord length from the leading edge, the leading edge has an arc shape, In the airfoil cross section of the basic shape that gradually increases in thickness from the edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge, the skeleton line is positive on the leading edge side near the trailing edge. A moving blade of an axial blower characterized by having a shape warped on the pressure side. It has an airfoil cross-sectional shape, its skeletal line warps to the suction side, its apex position exists up to 50% of the chord length from the leading edge, the leading edge has an arc shape, In the airfoil cross section of the basic shape where the thickness gradually increases from the edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge, the arc shape is formed on the pressure surface side near the trailing edge. A moving blade of an axial blower characterized by having a shape having a convex portion. It has an airfoil cross-sectional shape, its skeletal line warps to the suction side, its apex position exists up to 50% of the chord length from the leading edge, the leading edge has an arc shape, In the airfoil cross section of the basic shape, where the thickness gradually increases from the edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge, an arc shape is formed on the suction surface side near the trailing edge. A moving blade of an axial blower characterized by having a shape having a convex portion. It has an airfoil cross-sectional shape, its skeletal line warps to the suction side, its apex position exists up to 50% of the chord length from the leading edge, the leading edge has an arc shape, In the airfoil cross section of the basic shape where the thickness gradually increases from the edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge, the pressure side and suction side near the trailing edge A rotor blade of an axial-flow fan, characterized in that it has a shape having arc-shaped convex portions on both sides of the fan. It has an airfoil cross-sectional shape, its skeletal line warps to the suction side, its apex position exists up to 50% of the chord length from the leading edge, the leading edge has an arc shape, In the airfoil cross section of the basic shape that gradually increases in thickness from the edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge, the skeleton line is positive on the leading edge side near the trailing edge. A moving blade of an axial-flow fan, characterized in that it is warped on the pressure surface side and has an arc-shaped convex portion on the pressure surface side near the trailing edge. It has an airfoil cross-sectional shape, its skeletal line warps to the suction side, its apex position exists up to 50% of the chord length from the leading edge, the leading edge has an arc shape, In the airfoil cross section of the basic shape that gradually increases in thickness from the edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge, the skeleton line is positive on the leading edge side near the trailing edge. A moving blade of an axial-flow fan, characterized in that it is warped on the pressure surface side and has an arc-shaped convex portion on the suction surface side near the trailing edge. It has an airfoil cross-sectional shape, its skeletal line warps to the suction side, its apex position exists up to 50% of the chord length from the leading edge, the leading edge has an arc shape, In the airfoil cross section of the basic shape that gradually increases in thickness from the edge, has the maximum thickness at the top of the warp, and gradually decreases toward the trailing edge, the skeleton line is positive on the leading edge side near the trailing edge. A moving blade of an axial-flow fan, characterized in that it is warped on the pressure surface side and has arcuate convex portions on both the pressure surface side and the suction surface side near the trailing edge. It is driven by an electric motor capable of normal rotation and reverse rotation, and has one stage of an impeller having a moving blade according to any one of claims 1 to 7, and can blow air in the forward direction and the reverse direction by switching the rotation direction of the impeller. An axial blower characterized by being. It is driven by an electric motor capable of normal rotation and reverse rotation, and has two stages of impellers having the moving blades according to any one of claims 1 to 7, and the moving blades of the respective impellers are attached so that the trailing edges face each other. An axial blower characterized in that it can blow in the forward and reverse directions by switching the rotation direction. It is driven by an electric motor capable of normal rotation and reverse rotation, and has two stages of impellers having the moving blades according to any one of claims 1 to 7, all of the moving blades have the same shape and are attached to the respective impellers. An axial-flow blower characterized in that the attachment angle of the moving blades is different by 180 degrees, and the same performance can be blown in the forward direction and the reverse direction by switching the rotation direction of the impeller.

Images