JP2021188605A - Fan device - Google Patents

Abstract

To suppress the leakage of gas from a clearance between an insertion hole of a casing for housing an impeller and a motor shaft.SOLUTION: An impeller in which a plurality of blade pieces are radially arranged with respect to a rotary shaft is housed in a casing, an insertion hole 33 through which a shaft 41 of a motor 40 for rotating an impeller is inserted is formed at one axial end face 30a of the rotary shaft, and an air intake port is formed at the other axial end face at a side opposite to the one axial end face. Also, by extending an air blowing path from a periphery of the casing, and rotating the impeller by the drive of the motor, gas sucked from the air intake port is sent out to the air blowing path. Then, a rotary blade 50 which rotates with the rotation of the impeller, and in which a plurality of axial flow blades 54 for generating air flow toward one end face are arranged is attached to the shaft, between one end face of the casing and the motor.SELECTED DRAWING: Figure 5

Description

The present invention relates to a fan device that rotates an impeller in a casing by driving an external motor.

A combustion device that burns fuel gas, such as a water heater, is generally connected to a fan device for supplying combustion air and discharging exhaust gas after combustion. For example, as in Patent Document 1, a fan device is connected to the exhaust side of the combustion device to suck exhaust gas, and as in Patent Document 2, the fan device is connected to the air supply side of the combustion device to provide combustion air. The push-in type that sends in is known.

Such a fan device includes an impeller in which a plurality of blade pieces are arranged radially with respect to a rotating shaft, a casing for accommodating the impeller, and a motor in which a shaft is fixed to the rotating shaft of the impeller to rotate the impeller. It is equipped with. The casing is provided with an insertion hole for inserting the shaft on one end surface in the axial direction of the rotating shaft, and an intake port is provided on the other end surface on the opposite side to the one end surface, so that the air passage extends from the peripheral surface. Has been done. When the impeller rotates due to the drive of the motor, gas is blown out from the inside to the outside of the impeller by centrifugal force, so that the gas sucked from the intake port can be sent out to the air passage.

Japanese Unexamined Patent Publication No. 10-232053 Japanese Unexamined Patent Publication No. 2005-180179

However, in the fan device as described above, there is a gap between the insertion hole on one end surface of the casing and the shaft of the motor, and when the pressure inside the casing increases due to a blockage on the air passage side or the like, this gap There is a problem that the gas in the casing may leak out from the casing. In particular, in the tension type fan device connected to the exhaust side of the combustion device, the exhaust gas leaks from the gap, and even in the push-in type fan device connected to the air supply side of the combustion device, the combustion device can be used. The gas that should be sent in may leak through the gap.

The present invention has been made in response to the above-mentioned problems of the prior art, and provides a fan device capable of suppressing gas leakage from a gap between a casing insertion hole and a motor shaft. The purpose.

In order to solve the above-mentioned problems, the fan device of the present invention adopts the following configuration. That is,
In a fan device that is connected to a combustion device that burns fuel gas, can supply combustion air, and can discharge exhaust gas after combustion.
An impeller with multiple blade pieces arranged radially with respect to the axis of rotation,
The casing that houses the impeller and
A motor in which a shaft is fixed to the rotating shaft of the impeller to rotate the impeller, and
An insertion hole formed in one end surface of the rotary shaft in the axial direction of the casing and through which the shaft is inserted,
An intake port opened in the casing on the other end surface opposite to the one end surface,
It is provided with an air passage extending from the peripheral surface of the casing.
By rotating the impeller by driving the motor, the gas sucked from the intake port is sent out to the air passage.
The rotary blade is arranged between the one end surface of the casing and the motor, and is provided with a plurality of axial flow blades that rotate with the rotation of the impeller and generate an air flow toward the one end surface. It is characterized by being attached to the shaft.

In such a fan device of the present invention, when the rotary blade rotates with the rotation of the impeller, the axial flow blade generates an air flow toward one end surface of the casing, and the air flow causes the space between the one end surface and the rotary blade. Then the pressure rises and is kept at positive pressure. Therefore, even when the pressure inside the casing increases due to blockage on the air passage side, it is possible to prevent gas from leaking from the gap between the insertion hole on one end surface and the shaft of the motor.

In the fan device of the present invention described above, the exhaust gas may be sucked by rotating the impeller by connecting the intake port to the exhaust side of the combustion device.

In a tensile fan device that is connected to the exhaust side of the combustion device and sucks exhaust gas in this way, when the pressure inside the casing increases due to blockage on the air passage side, etc., the gap between the insertion hole on one end surface and the shaft of the motor Exhaust gas may leak from the air, but as described above, the airflow generated by the axial flow blade keeps the pressure between one end surface and the rotary blade at a positive pressure to suppress the leakage of exhaust gas from the gap. It becomes possible to do.

In addition to the axial flow blades, the rotary blades in the fan device of the present invention may be integrally provided with a plurality of centrifugal blades that generate an air flow from the inside to the outside in the radial direction.

In this way, when the rotor rotates, the centrifugal blades generate an air flow from the inside to the outside in the radial direction, and while cooling the motor by this air flow, the insertion hole on one end surface and the motor are described as described above. It is possible to suppress gas leakage from the gap with the shaft. In particular, in a tension type fan device, the casing becomes hot due to suction of high temperature exhaust gas, and the temperature of the motor tends to rise due to the radiant heat. By the presence of the above, the air heated by the radiant heat is expelled to the outside in the radial direction, so that the heat transfer from the casing to the motor is suppressed, and the temperature rise of the motor can be reduced.

In the fan device of the present invention described above, the following may be used. First, the rotary blade is provided with a rotary disk mounted substantially perpendicular to the shaft, and a plurality of through holes formed in the rotary disk so as to surround the shaft. Further, a plurality of centrifugal blades are erected radially with respect to the shaft from the surface of the rotating disk on the motor side. The axial flow blade is provided so that the air between the rotating disk and the motor can be sent to the casing side through the through hole as the rotating disk rotates.

By doing so, when the rotor is rotated, an air flow toward one end surface of the casing by the axial flow blade is generated through a plurality of through holes surrounding the shaft, and the positive pressure around the insertion hole is increased by increasing the positive pressure. It is possible to effectively suppress gas leakage from the gap between the insertion hole and the shaft. Further, on the surface of the rotary disk on the motor side, a centrifugal force acts on the air pushed in the rotational direction by the centrifugal blades, so that an air flow blown from the inside to the outside in the radial direction can be generated.

Further, in the above-mentioned fan device of the present invention, the axial flow blade may be tilted with respect to the rotating disk so that the trailing edge side is located on the casing side rather than the front edge side in the rotation direction of the rotating disk.

In this way, when the rotor blades rotate, air is pushed out toward the casing along the inclination of the axial flow blades, so that an air flow toward one end surface of the casing can be generated.

In such a fan device of the present invention, the number of axial flow blades and the number of centrifugal blades in the rotary blade may be different.

In general, when a rotating body having n blades rotates, noise of the nth-order component (frequency n times the rotation frequency) caused by the blades is remarkably generated. Therefore, if the number of axial flow blades and the number of centrifugal blades are different, the noise caused by the axial flow blades and the noise caused by the centrifugal blades can be avoided from resonating with each other, and the noise of the entire rotary blade can be reduced. It becomes possible to plan.

It is explanatory drawing which showed the rough structure of the water heater 1 as an example of the combustion device to which the fan device 10 of this embodiment is connected. It is a perspective view which showed the disassembled state of the fan apparatus 10 of this Example. It is sectional drawing which cut | cut the fan apparatus 10 of this Example by the plane including the shaft 41 of a motor 40. It is explanatory drawing which showed the shape of the rotary vane 50 of this Example. It is explanatory drawing which showed the air flow generated by the rotation of the rotary blade 50 of this Example. It is sectional drawing which showed the shape of the rotary vane 50 of the 1st modification. It is a perspective view which showed the shape of the rotary vane 50 of the 2nd modification. It is a perspective view which showed the state which disassembled the rotary blade 50 of the 3rd modification. It is explanatory drawing which showed the rough structure of the push-in type water heater 1 in which the fan device 10 was connected to the air supply side.

FIG. 1 is an explanatory diagram showing a rough configuration of a water heater 1 as an example of a combustion device to which the fan device 10 of this embodiment is connected. As shown in the figure, a burner 3 for burning a mixed gas of fuel gas and combustion air is mounted inside the box-shaped can body 2 of the water heater 1, and the fuel gas is burned through the gas supply path 4. It is supplied to 3.

A heat exchanger 5 is provided above the burner 3. The heat exchanger 5 has a water supply passage 6 connected to one end and a hot water supply passage 7 connected to the other end. The water supplied through the water supply passage 6 is heated by heat exchange in the heat exchanger 5 with the exhaust gas after combustion in the burner 3, becomes hot water, and flows out to the hot water supply passage 7.

The suction side of the fan device 10 is connected to the upper part of the can body 2, and the exhaust duct 8 is connected to the discharge side of the fan device 10. Further, an air intake port 9 is opened at the lower portion of the can body 2. When the fan device 10 operates, the exhaust gas that has passed through the heat exchanger 5 is sucked and sent out to the exhaust duct 8, and the exhaust gas that has passed through the exhaust duct 8 is discharged to the outside from the exhaust port 8a at the end. As described above, the water heater 1 of the present embodiment is a tension type in which the fan device 10 is connected to the exhaust side of the combustion device to suck the exhaust gas, and air is taken in from the intake port 9 as the exhaust gas is discharged. Combustion air is supplied to the burner 3.

FIG. 2 is a perspective view showing a state in which the fan device 10 of this embodiment is disassembled. As shown in the figure, the fan device 10 includes an impeller 20 that generates wind by rotating, a casing 30 that accommodates the impeller 20, a motor 40 that rotates the impeller 20, and the like.

The impeller 20 has a cylindrical shape in which a plurality of blade pieces 21 are arranged radially at predetermined intervals with respect to the rotation axis. One end of these blade pieces 21 in the axial direction (front side in the figure) is joined to the outer edge portion of the circular rotating substrate 22, and the other end (back side in the figure) is an annular support plate. It is joined to 23. The shaft 41 of the motor 40 is fixed to the center (rotating shaft) of the rotating substrate 22, and the impeller 20 rotates about the shaft 41 by driving the motor 40.

The casing 30 is formed by joining a first case 31 machined in a concave shape with a sheet metal and a second case 32 machined in a concave shape facing the first case 31 with a sheet metal at an outer edge portion. An insertion hole 33 through which the shaft 41 of the motor 40 is inserted is provided in the basal plane 30a facing the rotating substrate 22 in the first case 31, which is one end surface of the impeller 20 in the casing 30 in the rotation axis direction. On the other hand, an intake port 34 connected to the upper part of the can body 2 is provided on the covering surface 30b of the casing 30 facing the support plate 23 in the second case 32, which is the other end surface on the opposite side to the basal plane 30a. ing.

Further, the peripheral surface 30c surrounding the outer periphery of the impeller 20 in the casing 30 is formed so that the radius with respect to the rotation axis of the impeller 20 increases in the rotation direction of the impeller 20. An air passage 35 is provided extending in the tangential direction from the side having a large radius of the peripheral surface 30c, and the exhaust duct 8 is connected to the discharge port 36 at the end of the air passage 35.

In addition, in the first case 31, a plurality of (three in the illustrated example) support bases 38 for supporting the motor 40 at intervals from the basal plane 30a are attached to the basal plane 30a from the outside of the casing 30. Has been done. The motor 40 has a plurality of joints 42 (three in the illustrated example) protruding outward in the radial direction at the end facing the basal plane 30a, and the joints 42 are screwed to the support base 38 (three in the illustrated example). It is fixed using (not shown).

Further, between the basal surface 30a of the casing 30 and the motor 40 in the fan device 10 of the present embodiment, the shaft 41 of the motor 40 is attached and rotates with the rotation of the impeller 20 to generate an air flow. A rotary blade 50 provided with a plurality of blades is installed. The shape of the rotary blade 50 will be described later with reference to another figure.

FIG. 3 is a cross-sectional view of the fan device 10 of this embodiment cut along a plane including the shaft 41 of the motor 40. In FIG. 3, the vertical arrangement of the fan device 10 is inverted with respect to FIG. As described above, the casing 30 is formed by joining the first case 31 and the second case 32 at the outer edge portion, and the shaft 41 of the motor 40 is inserted through the basal plane 30a on the first case 31 side. An insertion hole 33 is provided.

The shaft 41 of the motor 40 is fixed to the center of the rotating substrate 22, and when the impeller 20 is rotated by the drive of the motor 40, the impeller 20 is radially between each of the plurality of blade pieces 21 due to centrifugal force. An airflow that blows from the inside to the outside is generated. Then, since the inside of the impeller 20 becomes a negative pressure, the exhaust gas from the intake port 34 connected to the upper part (exhaust side) of the can body 2 passes through the central opening of the annular support plate 23 and is inside the impeller 20. Is sucked into. The white arrows in the figure schematically represent the flow of exhaust gas. Then, the exhaust gas blown out to the outside of the impeller 20 travels along the peripheral surface 30c of the casing 30 and is sent out to the exhaust duct 8 connected to the discharge port 36 through the air passage 35.

In the water heater 1 to which such a fan device 10 is connected, blockage may occur due to corrosion or accumulation of dust or the like on the exhaust duct 8 due to aging, or strong wind blowing on the exhaust port 8a. be. When the exhaust gas cannot be sent out from the discharge port 36 due to the blockage on the air passage 35 side and the pressure inside the casing 30 (between the impeller 20 and the casing 30) increases, the insertion hole 33 of the basal plane 30a and the shaft 41 of the motor 40 Exhaust gas may leak from the gap between the casing. Therefore, in the fan device 10 of the present embodiment, a space is provided between the basal plane 30a of the casing 30 and the motor 40 by a support base 38, and the following rotary blades 50 are rotated in conjunction with the impeller 20. By installing it as possible, it is possible to suppress leakage of exhaust gas from the gap between the insertion hole 33 and the shaft 41.

FIG. 4 is an explanatory diagram showing the shape of the rotary blade 50 of this embodiment. First, in FIG. 4A, the entire rotary blade 50 is shown in a perspective view. The rotary blade 50 has a circular rotary disk 51 that is mounted substantially perpendicular to the shaft 41 of the motor 40, and a mounting hole 52 through which the shaft 41 is passed is provided in the center of the rotary disk 51. There is. As shown, a plurality of (seven in the illustrated example) through holes 53 surrounding the mounting holes 52 are provided at equal intervals toward the center side of the rotary disk 51, and each through hole 53 is provided. Is provided with an axial flow blade 54.

The axial flow blade 54 of this embodiment is formed by cutting and raising from the rotating disk 51. That is, the axial flow blade 54 has a contour cut out from the rotary disk 51, leaving a connecting portion on the front edge side in the rotation direction of the rotary blade 50 (clockwise indicated by the thick arrow in the figure). The portion is bent toward the casing 30 side (upper side in the figure). The inner portion of the contour obtained by cutting out the axial flow blade 54 from the rotating disk 51 is the through hole 53.

FIG. 4B shows a cross section of the rotary blade 50 cut at the position of PP in FIG. 4A. As shown in the figure, the axial flow blade 54 is inclined with respect to the rotary disk 51 so that the trailing edge side of the rotary blade 50 is located on the casing 30 side (upper side in the drawing) rather than the front edge side in the rotation direction. .. When the rotary blade 50 is rotated by the drive of the motor 40, air is pushed out to the casing 30 (base bottom surface 30a) side along the inclination of the axial flow blade 54 on the surface of the rotary disk 51 on the casing 30 side. As shown by the white arrow, an air flow in the direction of the rotation axis toward the basal plane 30a is generated. Then, behind the axial flow blade 54 in the rotation direction of the rotary blade 50, the pressure drops and becomes a negative pressure, so that air flows from the motor 40 side of the rotary disk 51 to the casing 30 side through the through hole 53. ..

Further, as shown in FIG. 4A, in the rotary blade 50 of the present embodiment, in addition to the axial flow blade 54, a plurality of (in addition to the axial flow blade 54) are located at positions radially outside the through hole 53 of the rotary disk 51. (9 pieces in the illustrated example) centrifugal blades 56 are erected radially with respect to the shaft 41 from the surface of the rotary disk 51 on the motor 40 side.

The illustrated centrifugal blade 56 cuts the front edge side of the notch 55 in the rotation direction of the rotary blade 50 when a plurality of (nine in the illustrated example) notches 55 are provided along the outer edge of the rotary disk 51. The remaining portion is bent toward the motor 40 (lower side in the figure), and the centrifugal blade 56 is substantially perpendicular to the rotating disk 51. Then, when the rotary blade 50 is rotated by the drive of the motor 40, centrifugal force acts on the air pushed in the rotational direction by the centrifugal blade 56 on the surface of the rotary disk 51 on the motor 40 side, so that the rotary blade 50 is in the radial direction. An airflow that blows from the inside to the outside is generated.

FIG. 5 is an explanatory diagram showing an air flow generated by the rotation of the rotary blade 50 of this embodiment. In the figure, a cross section of the fan device 10 cut by a plane including the shaft 41 of the motor 40 is shown, the space between the basal plane 30a of the casing 30 and the motor 40 is enlarged, and the distance between the basal plane 30a and the motor 40 is shown. The illustration of the support base 38 for providing the support base 38 is omitted. Further, the white arrow shown on the right side of the shaft 41 in the figure schematically represents the air flow generated by the rotation of the rotary blade 50.

As described above, the rotary blade 50 of the present embodiment includes two types of blades, an axial flow blade 54 and a centrifugal blade 56, and the rotary blade 50 rotates with the rotation of the impeller 20 driven by the motor 40. The axial flow vane 54 generates a flow that sends (pushes) air from the motor 40 side of the rotary disk 51 to the basal plane 30a side through the through hole 53. Due to such an air flow in the direction of the rotation axis toward the basal plane 30a, the pressure rises between the basal plane 30a and the rotary disk 51 and is maintained at a positive pressure. Therefore, the insertion hole 33 of the basal plane 30a and the motor 40 It is possible to suppress the leakage of exhaust gas from the gap between the shaft 41 and the shaft 41. In particular, in the rotary blade 50 of the present embodiment, a plurality of through holes 53 are arranged close to the center of the rotary disk 51 (surrounding the mounting hole 52) to increase the positive pressure around the insertion hole 33. By setting it, it is possible to improve the effect of suppressing the leakage of exhaust gas.

On the other hand, the centrifugal blade 56 generates an air flow that blows out from the inside to the outside in the radial direction on the motor 40 side of the rotating disk 51. At this time, although the pressure decreases radially inside the centrifugal blade 56, the negative pressure does not proceed because air flows in from the motor 40 side and is replenished. In addition, when the positive pressure increases due to the pushing of air by the axial flow blade 54 described above between the basal plane 30a and the rotary disk 51, an air flow that releases the positive pressure to the outside in the radial direction is generated.

In the fan device 10 connected to the exhaust side of the tension type water heater 1 and sucking high-temperature exhaust gas, the casing 30 becomes hot, and the temperature of the motor 40 rises due to the radiant heat thereof. However, as described above, the presence of an air flow from the inside to the outside in the radial direction between the casing 30 and the motor 40 causes the air heated by the radiant heat to be expelled to the outside in the radial direction. The transfer of heat to the 40 is suppressed, and the temperature rise of the motor 40 can be reduced. Further, since new air flows into the inside of the rotary blade 50 in the radial direction from the motor 40 side and is replenished, the effect of cooling the motor 40 can be obtained by this air flow.

As described above, the rotary blade 50 of the present embodiment is integrally provided with the plurality of axial flow blades 54 and the plurality of centrifugal blades 56, and when the rotary blade 50 rotates, the rotary blade 50 is directed toward the basal plane 30a of the casing 30. Airflow in the direction of the rotation axis can be generated, and airflow can be generated from the inside to the outside in the radial direction. It is possible to suppress the temperature rise of the motor 40 while suppressing the leakage of the exhaust gas.

Further, in the rotary blade 50 of the present embodiment, the number of axial flow blades 54 (7 blades) and the number of centrifugal blades 56 (9 blades) are intentionally different. In general, when a rotating body having n blades rotates, noise of the nth-order component (frequency n times the rotation frequency) caused by the blades is remarkably generated. Therefore, if the number of blades of the two types is different from each other as in this embodiment, the noise caused by the axial flow blade 54 and the noise caused by the centrifugal blade 56 can be avoided, and the entire rotary blade 50 can be avoided. It is possible to reduce the noise in.

The fan device 10 of the present embodiment described above also has the following modifications. Hereinafter, a modified example will be described with a focus on points different from those of the above-described embodiment. In the description of the modified example, the same reference numerals are given to the same configurations as those of the above-described embodiment, and the description thereof will be omitted.

In the rotary blade 50 of the fan device 10 of the above-described embodiment, the axial flow blade 54 is cut out from the rotary disk 51 leaving a connecting portion on the front edge side in the rotation direction, and is bent toward the casing 30 side at the connecting portion (the joint portion). See FIG. 4 (b)). On the other hand, in the rotary blade 50 of the fan device 10 of the first modification, as shown in FIG. 6, the axial flow blade 54 is cut out from the rotary disk 51 on the trailing edge side in the rotational direction, leaving a connecting portion. , It is bent toward the motor 40 side (lower side in the figure) at this connecting portion. Therefore, in the axial flow blade 54, the front edge side of the rotary blade 50 in the rotation direction protrudes toward the motor 40 from the rotary disk 51, and the trailing edge side is closer to the casing 30 side (upper side in the drawing) than the front edge side. It is inclined with respect to the rotating disk 51 so as to be located.

When the rotary blade 50 of the first modification is rotated by the drive of the motor 40, the axial flow blade 54 allows air on the motor 40 side (lower side in the figure) of the rotary disk 51 to be taken into the base bottom surface 30a of the casing 30. Since it is pushed to the side (upper side in the figure), as shown by the white arrow in the figure, an air flow in the rotation axis direction from the motor 40 side of the rotary disk 51 to the basal plane 30a through the through hole 53 is generated. .. Due to this air flow, the pressure rises between the basal plane 30a and the rotary disk 51 and is maintained at a positive pressure, as in the above-described embodiment. Therefore, the insertion hole 33 of the basal plane 30a and the shaft 41 of the motor 40 are maintained. It is possible to suppress the leakage of exhaust gas from the gap between the two.

FIG. 7 is a perspective view showing the shape of the rotary blade 50 of the second modification. In addition to the axial flow blade 54, the rotary blade 50 of the above-described embodiment is integrally provided with a centrifugal blade 56. On the other hand, the rotary blade 50 of the second modification is not provided with the centrifugal blade 56, but is provided with only the axial flow blade 54. In the example shown in FIG. 7, the rotating disk 51 is thick, and a plurality (7 pieces) of axial flow blades 54 are provided at equal intervals on the outer side in the radial direction from the outer peripheral surface of the rotating disk 51. Further, each axial flow vane 54 is inclined with respect to the rotary disk 51 so that the trailing edge side of the rotary blade 50 is located on the casing 30 side (upper side in the drawing) with respect to the front edge side in the rotation direction.

When the rotary blade 50 of the second modification is rotated by the drive of the motor 40, the axial flow blade 54 generates an air flow in the rotation axis direction toward the basal plane 30a (upper side in the drawing) of the casing 30. Similar to the above-described embodiment, by keeping the pressure between the basal plane 30a and the rotating disk 51 at a positive pressure, the exhaust gas leaks from the gap between the insertion hole 33 of the basal plane 30a and the shaft 41 of the motor 40. Can be suppressed. If the rotary blade 50 is integrally provided with the axial flow blade 54 and the centrifugal blade 56 as in the above-described embodiment, it is possible to suppress the temperature rise of the motor 40 while suppressing the leakage of exhaust gas. Will be.

FIG. 8 is a perspective view showing a state in which the rotary blade 50 of the third modification is disassembled. Whereas the rotary blade 50 of the above-described embodiment was one member, the rotary blade 50 of the third modification is two members of the first disk 51a and the second disk 51b as shown in the figure. It is composed of. First, the first disk 51a facing the basal plane 30a of the casing 30 is provided with a central mounting hole 52a, a through hole 53, and an axial flow blade 54 in the same manner as in the above-described embodiment. Further, the second disk 51b facing the motor 40 is provided with a central mounting hole 52b, a notch 55, and a centrifugal blade 56 in the same manner as in the above-described embodiment. In the rotary blade 50 of the third modification, the number of axial flow blades 54 (the number of through holes 53) and the number of centrifugal blades 56 are the same, and the number of two adjacent through holes 53 in the circumferential direction is the same. A centrifugal blade 56 is arranged between the two.

By joining the first disk 51a and the second disk 51b, the rotary blade 50 of the third modification is integrally provided with the axial flow blade 54 and the centrifugal blade 56. Therefore, when the rotary blade 50 of the third modification is rotated by the drive of the motor 40, the air flow in the rotation axis direction toward the basal plane 30a by the axial flow blade 54 and the radial direction by the centrifugal blade 56 are the same as in the above-described embodiment. Airflows from the inside to the outside are generated, and these airflows are used to raise the temperature of the motor 40 while suppressing leakage of exhaust gas from the gap between the insertion hole 33 of the basal plane 30a and the shaft 41 of the motor 40. Can be suppressed.

In the above-described embodiment in which the rotary blade 50 is one member, it is necessary to provide the centrifugal blade 56 at a position radially outside the through hole 53 of the rotary disk 51. In the rotary blade 50 of the third modification, the radial position of the centrifugal blade 56 is not limited to the outside of the through hole 53 by being composed of two members, and the radial position and the through hole of the centrifugal blade 56 are not limited. It is possible to partially overlap with the radial position of 53. As a result, it becomes easy to secure the radial length of the centrifugal blade 56 and the radial width of the through hole 53.

Although the fan device 10 of the present embodiment and the modified example has been described above, the present invention is not limited to the above-mentioned embodiment and the modified example, and can be carried out in various embodiments without departing from the gist thereof. Is.

For example, in the above-mentioned Examples and Modifications, the fan device 10 is described as being a tension type connected to the exhaust side of the water heater 1 to suck the exhaust gas. However, the present application is not limited to the tension type, and the present application can be suitably applied to the push-in type in which the fan device 10 is connected to the air supply side of the water heater 1 to send the combustion air.

FIG. 9 is an explanatory diagram showing a rough configuration of a push-in type water heater 1 in which a fan device 10 is connected to an air supply side. The same configuration as that of the tension type water heater 1 described with reference to FIG. 1 is designated by the same reference numerals and the description thereof will be omitted. As shown in the figure, in the push-in type water heater 1, the exhaust duct 8 is directly connected to the upper part of the can body 2. On the other hand, the discharge side of the fan device 10 is connected to the lower part of the can body 2, and the air supply duct 11 is connected to the suction side of the fan device 10. When the fan device 10 operates, the external air taken in from the air supply port 11a at the end of the air supply duct 11 is sucked into the fan device 10 through the air supply duct 11, and the combustion air is sent to the burner 3.

Further, the exhaust gas after combustion in the burner 3 is sent upward by the air blown by the fan device 10, and when it passes through the heat exchanger 5, it is discharged to the outside from the exhaust port 8a through the exhaust duct 8. In the illustrated example, a part of the air supply duct 11 has a double pipe structure in which the exhaust duct 8 is passed through the inside, and the air taken in from the outside is supplied to the burner 3 after being warmed by the residual heat of the exhaust gas. Therefore, the thermal efficiency can be improved.

Even in such a push-in type water heater 1, blockage may occur due to corrosion or accumulation of dust or the like on the exhaust duct 8 due to aging, or strong wind blowing on the exhaust port 8a, and the inside of the can body 2 may be blocked. When the pressure of the fan device 10 increases, air cannot be sent from the fan device 10 to the burner 3. As a result, as the pressure inside the casing 30 increases, the air warmed by the residual heat of the exhaust gas may leak from the gap between the insertion hole 33 of the basal plane 30a and the shaft 41 of the motor 40.

Therefore, as in the above-described embodiments and modifications, the rotary blade 50 is provided on the rotary blade 50 so as to be rotatably installed between the basal plane 30a of the casing 30 and the motor 40 in conjunction with the impeller 20. The axial flow blade 54 generates an air flow in the direction of the rotation axis toward the basal plane 30a, and keeps the pressure between the basal plane 30a and the rotary disk 51 at a positive pressure, whereby the insertion hole 33 of the basal plane 30a and the motor. It is possible to suppress the leakage of gas from the gap between the shaft 41 of the 40 and the shaft 41. Further, the effect of cooling the motor 40 can be obtained by generating an air flow from the inside to the outside in the radial direction by the centrifugal blade 56 provided on the rotary blade 50.

1 ... water heater, 2 ... can body, 3 ... burner,
4 ... gas supply path, 5 ... heat exchanger, 6 ... water supply passage,
7 ... hot water supply passage, 8 ... exhaust duct, 8a ... exhaust port,
9 ... Intake port, 10 ... Fan device, 11 ... Air supply duct,
11a ... Air supply port, 20 ... Impeller, 21 ... Wing piece,
22 ... Rotating board, 23 ... Support plate, 30 ... Casing,
30a ... basal plane, 30b ... covered surface, 30c ... peripheral surface,
31 ... 1st case, 32 ... 2nd case, 33 ... Insertion hole,
34 ... intake port, 35 ... air passage, 36 ... discharge port,
38 ... support, 40 ... motor, 41 ... shaft,
42 ... Fittings, 50 ... Rotor blades, 51 ... Rotating discs,
51a ... 1st disk, 51b ... 2nd disk, 52 ... Mounting hole,
53 ... Through hole, 54 ... Axial flow blade, 55 ... Notch,
56 ... Centrifugal blade.

Claims (6)

In a fan device that is connected to a combustion device that burns fuel gas, can supply combustion air, and can discharge exhaust gas after combustion.
An impeller with multiple blade pieces arranged radially with respect to the axis of rotation,
The casing that houses the impeller and
A motor in which a shaft is fixed to the rotating shaft of the impeller to rotate the impeller, and
An insertion hole formed in one end surface of the rotary shaft in the axial direction of the casing and through which the shaft is inserted,
An intake port opened in the casing on the other end surface opposite to the one end surface,
It is provided with an air passage extending from the peripheral surface of the casing.
By rotating the impeller by driving the motor, the gas sucked from the intake port is sent out to the air passage.
The rotary blade is arranged between the one end surface of the casing and the motor, and is provided with a plurality of axial flow blades that rotate with the rotation of the impeller and generate an air flow toward the one end surface. A fan device characterized by being mounted on a shaft. In the fan device according to claim 1,
A fan device characterized in that the intake port is connected to the exhaust side of the combustion device and the exhaust gas is sucked by rotating the impeller. In the fan device according to claim 1 or 2.
A fan device characterized in that the rotary blade is integrally provided with a plurality of centrifugal blades that generate an air flow from the inside to the outside in the radial direction in addition to the axial flow blade. In the fan device according to claim 3,
The rotary blade has a rotary disk mounted substantially perpendicular to the shaft, and a plurality of through holes formed in the rotary disk so as to surround the shaft.
The plurality of centrifugal blades are erected radially with respect to the shaft from the surface of the rotating disk on the motor side.
The axial flow vane is characterized in that the air between the rotary disk and the motor can be sent to the casing side through the through hole as the rotary disk rotates. Fan device. In the fan device according to claim 4,
The axial flow vane is a fan device that is inclined with respect to the rotary disk so that the trailing edge side of the rotary disk is located closer to the casing side than the front edge side in the rotational direction. In the fan device according to any one of claims 3 to 5.
The rotary blade is a fan device characterized in that the number of axial flow blades and the number of centrifugal blades are different.

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