JP6729938B2 - Ceiling fan - Google Patents

Description

The present invention relates to a ceiling fan.

Ceiling fans are often installed in facilities with large spaces such as factories, warehouses, sports facilities, and large commercial facilities. Due to the air flow generated by the ceiling fan, it is unlikely to feel uncomfortable even when the temperature is relatively high. Moreover, the efficiency of cooling and heating and humidity control by the air conditioning equipment can be improved by agitating the air. A ceiling fan that generates an air flow in a large space is required to have a large air volume.

To increase the air volume, large ceiling fans with blade lengths of several meters have been used for some time. However, the conventional large ceiling fan has a problem that the air flow is not uniform. For example, the space directly below and directly above the ceiling fan is a space where the fan itself obstructs the flow of air and makes it difficult for air to flow, but such a space is large because the fan is large. Further, eddies due to convection of air are likely to occur at a high position, and it is difficult for a person to feel comfort. In addition, a portion where the air flow is very high is likely to be locally generated, which may cause objects to be blown off or make people uncomfortable.

Therefore, in view of the above situation, an object of the present invention is to provide a ceiling fan that can generate a more uniform air flow with a large air volume.

In order to solve the above problems, the ceiling fan according to the present invention,
"A rotating shaft driven by a motor,
A rotating shaft supporting portion that rotatably supports the rotating shaft, and that is supported by being suspended from the ceiling;
In the shape of a long rod, a plurality of blade shafts that are radially attached to the rotation shaft and integrally rotate with the rotation shaft,
A blade supported by each of the plurality of blade shafts, and a ceiling fan,
The blade has a blade-free space along the blade axis, which is 10% to 30% of the diameter of a circle that is the outer shape of the rotation trajectory of the blade, and is centered on the rotation axis. Cage,
An outer winglet extends from the outer end of the blade in a direction intersecting the blade axis, and an inner winglet extends from the inner end of the blade in a direction intersecting the blade axis." Is.

In the ceiling fan of this configuration, a plurality of blades are radially attached to the rotary shaft that is rotationally driven by the motor via the blade shaft, but there are no blades around the rotary shaft along the blade shaft. It has a wingless space. That is, when the rotary shaft is rotated, the trajectory of the blade is donut-shaped when viewed from directly above or below, and the hole of the donut corresponds to the wingless space. By having such a wingless space, the flow of air generated by the rotation of the blades can go around to the wingless space, and the air circulates vertically through the wingless space. Therefore, in the conventional ceiling fan, the fan itself obstructs the flow of air, creating a space where it is difficult for air to circulate directly below and above the fan. The air can be circulated in the space, and the flow of the air can be made uniform.

Further, by having a wingless space around the axis of rotation, it is possible to provide an inner winglet at the inner end as well as an outer winglet at the outer end of the blade. Hereinafter, when the “outer winglet” and the “inner winglet” are not distinguished, they are simply referred to as “winglets”.

When the blade is rotating, the air pressure on the upper surface side is lower than the air pressure on the lower surface side, so that air wraps around the lower surface side from the lower surface side to the upper surface side to generate a blade tip vortex. Such wraparound of air can be suppressed by extending the winglet from the end portion of the blade in a direction intersecting the axial direction of the blade. When the blade tip vortex is generated, the blast energy obtained by converting the kinetic energy of the blade is consumed. Therefore, by suppressing the generation of the blade tip vortex, the air volume can be increased. In the present configuration, since the winglets having such an action are provided at both the outer end portion and the inner end portion of the blade, the action and effect thereof are very large, and the air volume can be greatly increased.

Here, the “outer winglet” and the “inner winglet” are both upward and downward with respect to the blade regardless of whether they extend upward or downward. It may be extended to.

Further, as will be described later in detail, in the indoor space in which the ceiling fan of this configuration is installed, the deviation of the wind speed distribution is smaller than that in the case where the ceiling fan of the comparative example is installed. That is, according to the ceiling fan of this configuration, a more uniform air flow can be generated.

The ceiling fan according to the present invention, in addition to the above configuration,
"The rotary shaft is a cylindrical hollow shaft part that is driven to rotate by the motor, and the blade shaft is supported and inserted into the hollow shaft part to rotate integrally with the hollow shaft part. Equipped with a shaft that can slide in the axial direction,
The rotating shaft support portion is box-shaped, rotatably supports the hollow shaft portion therein, and has a space above and below the elevating shaft portion to allow axial sliding of the elevating shaft portion. Have”.

The lift force acting on the blade by rotating the blade exerts a thrust force that pushes it up in the axial direction of the rotating shaft. In the conventional ceiling fan, this thrust acts on the motor and the speed reducer via the rotary shaft, so that the gears and the like that mesh with each other are loaded.

On the other hand, in this configuration, the rotating shaft has a double structure of a cylindrical hollow shaft portion and an elevating shaft portion inserted therein. The elevating shaft portion rotates integrally with the hollow shaft portion, and can slide in the hollow shaft portion in the axial direction, that is, can be vertically moved up and down, and the hollow shaft portion can be freely rotated. A space is provided inside the rotating shaft support portion that is supported to allow the elevator shaft portion to move up and down. Therefore, even if a thrust force that pushes up in the axial direction of the rotating shaft acts due to the lift force that acts on the blade, the lifting shaft portion slides upward to receive this force, and the hollow shaft portion and the motor that rotationally drives it. No thrust acts on the gear. As a result, it is possible to solve the problem of the conventional ceiling fan that the components of the motor are loaded due to the lift force acting on the blades.

In particular, the ceiling fan of the present invention has a large amount of air flow as compared with the conventional ceiling fan as described above, and accordingly, the thrust acting to push up the rotary shaft also increases accordingly. Is not transmitted to the components of the motor, etc. is a great advantage.

As described above, according to the present invention, it is possible to provide a ceiling fan that has a large air volume and that can generate a more uniform air flow.

It is the perspective view seen from the upper part of the ceiling fan of 1st embodiment of this invention, and the perspective view seen from the lower part. FIG. 2A is a plan view of a blade shaft, a blade, and a winglet in the ceiling fan of FIG. 1, FIG. 2B is an enlarged cross-sectional view taken along the line AA, and FIG. FIG. 2 is an exploded view of a configuration near a rotating shaft in the ceiling fan of FIG. 1. (A) Top view of the hollow shaft portion, (b) BB line sectional view, (c), exploded side view of the lifting shaft portion and the bearing, and (d) the hollow shaft portion and the lifting shaft portion are integrated. It is the CC sectional view taken on the line. (A), (b) It is a figure explaining the raising/lowering of the raising/lowering shaft part in the ceiling fan of FIG. It is a wind speed distribution map of the indoor space in which the ceiling fan of the example was installed. It is a wind speed distribution map of the indoor space which installed the ceiling fan of a comparative example. It is a schematic block diagram of the ceiling fan of 2nd embodiment of this invention.

Hereinafter, a ceiling fan that is a specific embodiment of the present invention will be described with reference to the drawings. First, the ceiling fan 1 according to the first embodiment will be described with reference to FIGS. 1 to 6.

The ceiling fan 1 of the first embodiment includes a motor 60, a rotary shaft 40 that is driven to rotate by the motor 60, a rotary shaft support portion 70 that supports the rotary shaft 40, and a rotary shaft support portion 70 that is mounted on a ceiling. A ceiling mount 80, a blade shaft 11 that rotates integrally with the rotating shaft 40, a hub 30 that connects the blade shaft 11 to the rotating shaft 40, a blade 10 supported by each of the plurality of blade shafts 11, and a blade. An outer winglet 21 and an inner winglet 22 extending from 10.

More specifically, the blade 10 is long and is supported by a hollow blade shaft 11 having a hollow rectangular rod shape. The airfoil of the blade 10 is not particularly limited, but in the present embodiment, the airfoil has a rounded front end and tapers toward the rear end (NACA airfoil). There are a plurality of blades 10 and blade shafts 11, and the blade shafts 11 are radially fixed to the rotating shaft 40 via the hub 30. That is, the plurality of blades 10 are provided around the rotation axis 40 at equal angular intervals. The number of blades 10 can be 3 to 10, and if it is 4 to 6, the balance between the weight and the blowing effect is good, which is preferable.

The blade shaft 11 supporting the blade 10 has a portion where the blade shaft 11 is exposed without the blade 10 by a predetermined length near the rotating shaft 40 (see FIG. 2A). Therefore, when the rotating shaft 40 is rotated and viewed from directly above or below, the surface D formed by the trajectory of the blade 10 has a donut shape (see the hatched portion in FIG. 2C). Then, in this donut-shaped surface D, the central space corresponding to the hole of the donut is the wingless space S. The diameter R2 of the wingless space S (the diameter R2 of the circle formed by the rotation locus of the inner end of the blade 10) is the outer diameter of the surface D formed by the rotation locus of the blade 10 and the diameter R1 of the circle (the blade 10 10% to 30% of the diameter R1) of the circle formed by the rotation locus of the outer end of the. When the ceiling fan is installed in a large space, the length of the diameter R1 can be 3 m to 6 m.

An outer winglet 21 extends from the outer end of the blade 10 in a direction intersecting the blade axis 11, and an inner winglet 22 extends from the inner end of the blade 10 in a direction intersecting the blade axis 11. It is extended. The outer winglet 21 and the inner winglet 22 of the present embodiment are flat plates having the same shape and having a larger area than the cross section of the blade 10. The outer winglet 21 and the inner winglet 22 extend upward and downward of the blade 10 in a direction orthogonal to the blade axis 11. Here, the outer shape of the outer winglet 21 and the inner winglet 22 is a shape in which both ends of a semi-arcuate front end side and both ends of a semi-arcuate rear end side are connected by straight lines on the same side. The case where the semicircular arc is larger in diameter than the rear semicircle is illustrated. The shape of the outer winglet and the inner winglet is not limited to this, and may be, for example, a similar shape of the cross section of the blade 10, a circular shape, an elliptical shape, or a polygonal shape. The areas of the outer winglets and the inner winglets may be 5 to 10 times the cross section of the blade 10. The thickness of the outer winglet 21 and the inner winglet 22 may be 1 mm to 5 mm, and is preferably 2 mm to 3 mm.

The motor 60 is an orthogonal shaft type, and its casing 65 is fixed to the side surface of the rotary shaft support portion 70 (see FIG. 3 ). The rotary shaft support portion 70 has a box-shaped outer shell 75, and supports the motor 60 in a state in which the drive shaft 61 of the motor 60 is horizontally inserted in the outer space 75. A bevel gear 62 is formed at the tip of a drive shaft 61 of the motor 60, and a bevel gear 41g meshing with the bevel gear 62 is coaxially integrated with the rotary shaft 40. As a result, the rotary shaft 40 is rotationally driven by the motor 60 with the direction orthogonal to the drive shaft 61 of the motor 60 as the axial direction. Although the rotation of the drive shaft 61 is transmitted to the rotary shaft 40 via the two bevel gears 62 and 41g, the rotation of the drive shaft 61 is transmitted to the rotary shaft 40 via three or more gears. 40 may be transmitted.

The rotating shaft 40 has a double structure of a hollow shaft portion 41 and a lifting shaft portion 42. The hollow shaft portion 41 has a cylindrical shape, and the elevating shaft portion 42 is inserted therein. It is the hollow shaft portion 41 that the bevel gear 41g is integrated. From the outer shell 75 of the rotary shaft support portion 70, a support fixing portion 73 projects toward the internal space, and the upper and lower portions of the hollow shaft portion 41 are fixed to the support fixing portion 73 via bearings 51. These bearings 51 are radial bearings in which rolling elements are held between an outer ring and an inner ring that are separated in the radial direction of the rotary shaft 40, and the rotation of the hollow shaft portion 41 is transmitted to the rotary shaft support portion 70 in the radial direction. This is prevented (see FIGS. 3 and 5). A key groove 41r having a U-shaped cross section is formed on the inner peripheral surface of the hollow shaft portion 41 over the entire length in the axial direction (see FIGS. 4A and 4B).

The elevating shaft part 42 has a main shaft part 42m having an outer diameter slightly smaller than the inner diameter of the hollow shaft part 41, and an upper shaft part coaxially extending upward from the main shaft part 42m with an outer diameter smaller than the main shaft part 42m. It has 42b and the lower shaft part 42c which has the outer diameter smaller than the main shaft part 42m, and has coaxially extended downward from the main shaft part 42m (refer FIG.4(c)). A bearing 52 is fixed around the upper shaft portion 42b, and an upper end of the upper shaft portion 42b does not project above the bearing 52. A bearing 52 is also fixed around the lower shaft portion 42c at the boundary with the main shaft portion 42m, but the lower shaft portion 42c extends below the bearing 52. These bearings 52 are thrust bearings in which rolling elements are held between an outer ring and an inner ring that are separated from each other in the axial direction of the rotating shaft 40, and the rotation of the elevating shaft part 42 is transmitted to the rotating shaft support part 70 in the axial direction. This is prevented (see FIGS. 3 and 5).

The main shaft portion 42m is longer in the axial direction than the hollow shaft portion 41. A key groove 42r having a U-shaped cross section is formed on the outer peripheral surface of the main shaft portion 42m. The key groove 42r of the elevating shaft portion 42 has a shorter axial length than the key groove 41r of the hollow shaft portion 41. The key grooves 41r and 42r are configured to integrally rotate the hollow shaft portion 41 and the elevating shaft portion 42 by using the key 40k. The key is 40k, and is a square column having a cross section of a size just fitted into a space formed when the key groove 41r of the hollow shaft portion 41 and the key groove 42r of the elevating shaft portion 42 face each other. The length is equal to the axial length of the key groove 42r of the elevating shaft portion 42. Accordingly, when the elevating shaft portion 42 is inserted into the hollow shaft portion 41 with the key 40k fitted in the key groove 42r, the elevating shaft portion 42 is prevented from idling with respect to the hollow shaft portion 41. It rotates integrally with the hollow shaft portion 41 (see FIG. 4D). As described above, since the key 40k having the same length as the key groove 42r of the elevating shaft portion 42 has a shorter axial length than the key groove 41r of the hollow shaft portion 41, the key 40k slides along the key groove 41r. Meanwhile, the elevating shaft part 42 can slide in the axial direction inside the hollow shaft part 41.

In the elevating shaft portion 42 integrated with the hollow shaft portion 41, the upper shaft portion 42b and the main shaft portion 42m are housed in the internal space of the rotating shaft support portion 70. In the outer shell 75 of the rotary shaft support portion 70, a hole 75h is formed so as to penetrate the bottom surface 75c, and a portion of the lower shaft portion 42c below the bearing 52 extends downward through the hole 75h. .. The hole portion 75h is larger than the outer diameter of the lower shaft portion 42c and smaller than the outer diameter of the bearing 52. The lower end of the lower shaft portion 42c is coaxially fixed to the hub center shaft 31 protruding upward from the center of the hub 30 (see FIG. 5).

The ceiling mount 80 has a pillar 81, and the pillar 81 is fixed to the top surface 75b of the outer shell 75 of the rotary shaft support portion 70 so as to project upward. By fixing the ceiling mount 80 to the ceiling, the rotary shaft 40 is suspended and supported on the ceiling via the rotary shaft support portion 70. At the same time, the motor 60 having the casing 65 fixed to the rotary shaft support 70 is also suspended and supported by the ceiling via the rotary shaft support 70.

Next, the operation of the ceiling fan 1 having the above configuration will be described. When the ceiling fan 1 is stopped, that is, when the motor 60 is not operating, the elevating shaft portion 42 slides downward on the rotating shaft 40, and the bearing 52 attached to the lower shaft portion 42c serves as the rotating shaft support portion. It is in contact with the bottom surface 75c of the outer shell 75 of 70 (see FIG. 5A). In this state, in the internal space of the rotating shaft support portion 70, between the upper end of the elevating shaft portion 42 and the top surface 75b of the outer shell 75, that is, the outer ring of the bearing 52 attached to the upper shaft portion 42b and the top surface 75b. A space Es exists between them.

When the motor 60 is operated, the hollow shaft portion 41 of the rotary shaft 40 rotates via the bevel gears 62 and 41g as the drive shaft 61 rotates. The elevating shaft portion 42 is inserted into the hollow shaft portion 41, and the engagement between the key grooves 41r, 42r and the key 40k prevents the hollow shaft portion 41 from rotating. It rotates integrally with the hollow shaft portion 41. Since the lower shaft portion 42c of the elevating shaft portion 42 is in contact with the bottom surface 75c of the rotating shaft supporting portion 70 via the bearing 52, the rotation of the elevating shaft portion 42 is not transmitted to the rotating shaft supporting portion 70. When the lifting shaft portion 42 rotates, the hub 30 to which the lower shaft portion 42c is fixed rotates, and the blade 10 rotates together with the blade shaft 11 fixed to the hub 30.

Due to the rotation of the blade 10, an air flow is generated and a lift force acts on the blade 10. The lift force is a thrust force that pushes up the blade 10, the blade shaft 11, and the hub 30 in the axial direction of the rotation shaft 40. As described above, since the key 40k fitted in the key groove 42r of the elevating shaft portion 42 is shorter than the key groove 41r of the hollow shaft portion 41, the elevating shaft portion 42 must slide in the hollow shaft portion 41 in the axial direction. In addition, there is an extra space Es between the upper end of the elevating shaft part 42 and the top surface 75b of the rotating shaft support part 70. Therefore, the elevating shaft portion 42 slides upward inside the hollow shaft portion 41 by the thrust. That is, the elevating shaft portion 42 rises (see FIG. 5B). Here, it is illustrated that the elevating shaft portion 42 is raised by a height h, and a gap E's is formed between the outer ring of the bearing 52 attached to the lower shaft portion 42c and the bottom surface 75c.

Even if the upper end of the elevating shaft portion 42 comes into contact with the top surface 75b of the rotating shaft support portion 70 due to this rise, the axial bearing 52 is fixed to the upper end of the elevating shaft portion 42. Therefore, the rotation of the lifting shaft portion 42 is not transmitted to the rotating shaft support portion 70, and the thrust acting in the axial direction of the rotating shaft 40 presses the rotating shaft support portion 70 against the ceiling via the ceiling mount 80. Acts as a force. Therefore, the thrust acting in the axial direction of the rotating shaft 40 is prevented from acting on the motor 60 via the hollow shaft portion 41 and the bevel gears 62, 41g transmitting the driving force by the motor 60 to the rotating shaft 40. The thrust can be received on the ceiling via the rotary shaft support 70 and the ceiling mount 80. The ceiling mount 80 having the box-shaped rotating shaft support 70 and the column 81 has a simple structure and high rigidity, and thus has high resistance to thrust.

Actually, the ceiling fan EX of the example of the first embodiment was attached to the ceiling of the building, and the air volume was measured. The diameter of the ceiling fan EX, that is, the diameter R1 of the circle that is the rotation locus of the blade was 5 m, and the ratio of the diameter R2 of the bladeless space S to the diameter R1 was 25%. The blade and blade shaft were made of aluminum, and the chord length of the blade was 200 mm. The number of blades is 5, and the outer winglets having the shape shown in FIG. 2(b) and the area ratio to the blade cross section are fixed to the outer ends of the blades, and the outer wing is attached to the inner ends of the blades. An inner winglet of the same shape and size as the let was fixed.

For comparison, the blade does not have the wingless space S and is continuous to the base end of the blade shaft (the end on the rotary shaft side), and only the outer end of the blade has the same outer wing as that of the embodiment. A sealing fan RE1 of a comparative example, which is provided with a ret and is otherwise the same as the ceiling fan EX of the example, was manufactured. Also, for comparison, the wingless space S is provided in the same manner as the embodiment, but the outer winglet and the inner winglet are not provided, and the others are the same as the ceiling fan EX of the embodiment. An example ceiling fan RE2 was made.

The ceiling fan EX of the example and the ceiling fans RE1 and RE2 of the comparative example are mounted on the ceilings of the rooms A and B having different sizes of the indoor spaces at a height position of 1 m from the ceiling and rotated at a rotation speed of 150 rpm. Let The size of the room A was 15 m×15 m×height 7.5 m, and the size of the room B was 30 m×30 m×height 7.5 m. In each of the rooms A and B, the temperature was adjusted to 20° C. and the relative humidity was 50%, and the gas density was 1.26 kg/m ³ . Table 1 shows the fan efficiency calculated based on the measured air volume and the shaft power of the motor.

As shown in Table 1, in the ceiling fan EX of the embodiment, the air volume is increased by 12% to 13%, and the fan efficiency is about 16%, compared with any of the ceiling fans RE1 and RE2 of the comparative example. It was rising. The ceiling fan RE1 of the comparative example in which there is no wingless space S and therefore only the outer winglet 21 is mounted, and the ceiling fan RE2 of the comparative example in which the wingless space S is provided but does not have a winglet are And the fan efficiency was about the same. From these facts, both providing the wingless space and attaching the winglets to both the outer end and the inner end of the blade contribute to increasing the air volume of the ceiling fan and improving the fan efficiency. You can see that

6 and 7 show wind velocity distribution diagrams obtained by CFD analysis when the ceiling fan EX of the example and the ceiling fan RE1 of the comparative example are operated in the room A, respectively.

Comparing FIG. 6 and FIG. 7, in the ceiling fan RE1 of the comparative example, there is almost no air flow in the space immediately below and immediately above the blade, and the blade itself obstructs the air flow in the vertical direction. Conceivable. On the other hand, in the ceiling fan EX of the embodiment, a vertical air flow that passes through the central portion of the fan is generated. It is considered that this is because the air flow generated by the rotation of the blades circulates into the wingless space, so that the air flows vertically through the wingless space.

Further, in the ceiling fan RE1 of the comparative example, the vortex due to the convection of air is formed at a high position in the corner near the boundary between the ceiling and the side wall. On the other hand, in the ceiling fan EX of the embodiment, it is understood that the air vortex is formed at a low position near 2 m above the floor, and the air flow is generated at a height where people can easily feel comfort. ..

In addition, in the ceiling fan RE1 of the comparative example, there is an extremely high wind velocity at a height very close to the floor surface, which blows off objects placed on the floor or hinders the work of a person in a low position. There is a risk of On the other hand, in the ceiling fan EX of the embodiment, the flow of high wind velocity does not exist locally, and the shape of the air vortex is almost circular. That is, in the ceiling fan EX of the embodiment, the air flow is more uniform as a whole than the ceiling fan RE1 of the comparative example.

As described above, according to the ceiling fan 1 of the present embodiment, since the blade-free space S is provided, the blades 10 themselves do not easily obstruct the air flow, and the central portion of the fan flows vertically. A flow of air is created. Further, by having both the outer winglet 21 and the inner winglet 22, generation of blade tip vortices is suppressed at both the outer end portion and the inner end portion of the blade 10. Due to these synergistic effects, the air volume is large and the fan efficiency is high as compared with the conventional ceiling fan, and a more uniform air flow can be generated.

Further, conventionally, in a large ceiling fan having a blade of 4 m or more, the wind noise of the blade becomes noise, and therefore, in order to suppress it, it was usual to rotate the blade at a low rotation speed of 25 rpm to 50 rpm. .. On the other hand, in the ceiling fan 1 of this embodiment, even if the blade 10 was rotated at a high speed of 150 rpm, the wind noise was similar to that of the conventional ceiling fan that was rotated at a low speed.

Furthermore, since the drive shaft 61 of the motor 60 is orthogonal to the rotary shaft 40 of the blade 10, the distance from the ceiling to the ceiling fan 1 is greater than when the rotary shaft of the blade and the drive shaft of the motor are coaxial. Can be set short.

In addition, the rotating shaft 40 has a double structure of the hollow shaft portion 41 and the elevating shaft portion 42, and the elevating shaft portion 42 is configured to be slidable in the hollow shaft portion 41 in the axial direction. Spaces Es and E's are provided inside the support portion 70 to allow the lifting shaft portion 42 to move up and down. An axial bearing 52 that does not transmit the torque to the rotary shaft support portion 70 is attached to the elevating shaft portion 42. Accordingly, even if a lift is generated by the rotation of the blade 10 and an axial thrust is applied to the rotary shaft 40, the thrust is received by the ceiling via the rotary shaft support portion 70 and the ceiling mount 80, and the thrust Can be prevented from acting as a load on the motor 60 or the bevel gears 62, 41g transmitting the driving force of the motor 60 to the rotary shaft 40.

Next, the ceiling fan 2 of the second embodiment will be described with reference to FIG. In FIG. 8, the same components as those of the ceiling fan 1 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The ceiling fan 2 differs from the ceiling fan 1 in the form of the outer winglet and the inner winglet. In the ceiling fan 1, one outer winglet 21 and one inner winglet 22 are attached to each of the plurality of blades 10. On the other hand, in the ceiling fan 2, the plurality of blades 10 share one outer winglet 25 and one inner winglet 26. The outer winglets 25 are annular flat plate members that connect the outer ends of the plurality of blades 10, and the inner winglets 26 are annular flat plate members that connect the inner ends of the plurality of blades 10. is there. The outer winglet 25 and the inner winglet 26 extend above and below the blade 10 in a direction orthogonal to the blade axis 11. The ceiling fan 2 having such a configuration also exhibits the same operation and effect as the ceiling fan 1.

Although the present invention has been described above with reference to the preferred embodiments, the present invention is not limited to the above-described embodiments, and various improvements are made within the scope not departing from the gist of the present invention as shown below. And the design can be changed.

For example, in the above embodiment, the case where the outer winglet and the inner winglet extend in the direction orthogonal to the blade axis is illustrated. However, the angle at which the outer winglet and the inner winglet intersect the blade axis may be an angle other than a right angle.

Further, in the above embodiment, the case where the outer winglet and the inner winglet extend above and below the blade has been illustrated. The present invention is not limited to this, and the winglet extending only above the blade or the winglet extending only below the blade can suppress the generation of the tip vortex. it can.

1, 2 Ceiling fan 10 Blade 11 Blade shaft 21, 25 Outer winglet 22, 26 Inner winglet 40 Rotating shaft 41 Hollow shaft (rotating shaft)
42 Lifting shaft part (rotating shaft)
60 motor 70 rotary shaft support

Claims (2)

A rotating shaft driven to rotate by a motor,
A rotating shaft supporting portion that rotatably supports the rotating shaft, and that is supported by being suspended from the ceiling;
In the shape of a long rod, a plurality of blade shafts that are radially attached to the rotation shaft and integrally rotate with the rotation shaft,
A blade supported by each of the plurality of blade shafts, and a ceiling fan,
The blade has a wingless space along the blade axis having a length of 10% to 30% of the diameter of a circle, which is the outer shape of the rotation locus of the blade, and having the blade as the center. Cage,
The outer winglet extends in a direction intersecting the blade axis from the outer end of the blade, and the inner winglet extends in a direction intersecting the blade axis from the inner end of the blade. Featured ceiling fan. The rotary shaft is a cylindrical hollow shaft part that is driven to rotate by the motor, and the blade shaft is supported and inserted into the hollow shaft part to rotate integrally with the hollow shaft part. It is equipped with a lifting shaft that can slide in any direction.
The rotating shaft support portion is box-shaped, rotatably supports the hollow shaft portion therein, and has a space above and below the elevating shaft portion to allow axial sliding of the elevating shaft portion. The ceiling fan according to claim 1, further comprising:

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