Cooling fan

Abstract

To simplify a structure of a cooling unit used in an object to be cooled (a cooled object) which may be immersed in water.SOLUTION: A cooling fan 10 includes: a cylindrical casing 20; a waterproof motor 30 attached to the casing 20; blades 35 disposed in the casing 20 to cool a cooled object 5; and a cover member 40 which may be moved by a buoyant force. The casing 20 includes: a body 21 in which an upper end is closed; and an attachment part 24 configured to be attached to the cooled object 5. A suction port 21a is formed at an upper part of the body 21 and an exhaust port 24a is formed at the attachment part 24. The cover member 40 may move from a lowered position where the cover member 40 opens the suction port 21a and a floated position where the cover member 40 covers the suction port 21a.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cooling fan. [Background technology]

[0002] The vertical pump disclosed in Patent Document 1 is equipped with a waterproof motor with a sealed motor casing, which allows it to continue operating even if unexpected water flows into the building due to a tsunami or other event, causing it to become submerged. Waterproof motors require a cooling unit to cool them during normal operation when they are not submerged. The cooling unit in Patent Document 1 is equipped with a jacket that is placed on the outside of the motor casing, and a cooling medium is enclosed between the motor casing and the jacket. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-83242 A Summary of the Invention [Problem to be solved by the invention]

[0004] The cooling unit of Patent Document 1 is large-scale and complicated in structure because it is necessary to attach a jacket to the pump casing in a liquid-tight manner and further seal in the cooling medium. Therefore, there is room for improvement in simplifying the structure of the cooling unit of Patent Document 1. This problem can also occur when cooling objects other than water-resistant motors.

[0005] An object of the present invention is to simplify the configuration of a cooling unit used for an object to be cooled that may be submerged in water. [Means for solving the problem]

[0006] One aspect of the present invention provides a cooling fan comprising a cylindrical casing having a main body extending in a vertical direction with an upper end closed, and an attachment portion connected to the lower end of the main body and attached to an object to be cooled, with an air intake formed at the top of the main body and an exhaust port formed in the attachment portion, a waterproof motor attached to the casing, blades disposed within the casing and rotated by the waterproof motor to suck in air through the air intake and expel it through the exhaust port to cool the object to be cooled, and a cover member that is movable by buoyancy from a descended position that opens the air intake to a raised position that covers the air intake.

[0007] The cooling unit is made up of a casing, a waterproof motor, and a cooling fan with blades. As a result, during normal operation of an object to be cooled that is not submerged, the rotation of the blades by the waterproof motor ensures that the object can be cooled. With this cooling fan, the casing does not need to be liquid-tight when attached to the object to be cooled, and no cooling medium needs to be enclosed. Therefore, the configuration can be simplified compared to a cooling unit made up of a jacket and a cooling medium.

[0008] The cooling fan is equipped with a cover member that can move by buoyancy from a lowered position where the intake port is open to a raised position where the intake port is covered. As a result, when the cooling fan is submerged together with the waterproof motor, the intake port can be covered by the cover member, preventing the intake port from being blocked by foreign objects such as dirt that flow in with the water. On the other hand, when the water level drops, the cover member also descends to open the intake port, ensuring an air flow path when the cooling process for the object to be cooled is resumed. Therefore, the object to be cooled can be cooled by the cooling fan without the operator having to perform any return operations, ensuring the operation of the object to be cooled. Effect of the Invention

[0009] The present invention can simplify the configuration of a cooling unit used for an object to be cooled that may be submerged in water. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a vertical pump equipped with a waterproof motor using a cooling fan according to a first embodiment. FIG. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of part II in FIG. [Diagram 3] Cross-sectional view of line III-III in Figure 2. [Figure 4] FIG. 3 is an enlarged cross-sectional view similar to FIG. 2, showing the submerged state. [Diagram 5] 2, showing a cooling fan according to a second embodiment. FIG. [Figure 6] 2, showing a cooling fan according to a third embodiment. FIG. [Figure 7] 2, showing a cooling fan according to a fourth embodiment. FIG. [Figure 8] Cross-sectional view taken along line VIII-VIII in Figure 7. [Figure 9] 10 is an enlarged cross-sectional view similar to FIG. 2, showing a cooling fan according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] (First embodiment) Referring to FIG. 1, a cooling fan (cooling unit) 10 according to a first embodiment of the present invention is attached to a waterproof motor (object to be cooled) 5 mounted on a vertical pump 1.

[0013] The waterproof motor 5 is used to continue the discharge operation of the vertical pump 1 even if unexpected water flows into the building and causes submersion. This waterproof motor 5 has a sealed motor casing 6 and is liquid-tightly attached to the cylindrical motor attachment part 2a of the discharge pipe (bent pipe) 2 that constitutes the upper part of the pump casing. The upper end of the motor casing 6 is provided with a truncated cone-shaped protrusion 6a that protrudes upward. Air-cooling fins 6b (see Figure 3) that protrude radially outward are provided below the protrusion 6a in order to increase the surface area.

[0014] The output shaft 7 protruding from the motor casing 6 is disposed inside the discharge pipe 2, and is connected to the rotating shaft 3 of the vertical pump 1 so as not to be rotatable relative to the rotating shaft 3. The water-resistant motor 5 rotates the rotating shaft 3 via the output shaft 7, thereby rotating an impeller (not shown) attached to the lower end of the rotating shaft 3, and discharging water from the suction tank downstream.

[0015] The cooling fan 10 is attached to the upper side of the motor casing 6 to forcibly cool the waterproof motor 5 by blowing air. The cooling fan 10 includes a fan casing 20, a waterproof motor 30, and blades 35. The cooling fan 10 also includes a floating ring (cover member) 40 that is capable of covering the air intake port 21a of the fan casing 20 by buoyancy.

[0016] Referring to FIG. 2, the fan casing 20 includes a cylindrical main body portion 21 and an attachment portion 24, each of which extends in the vertical direction.

[0017] The main body 21 is formed of a straight tube whose axis extends vertically. However, the main body 21 may be inclined with respect to the vertical direction as long as the floating ring 40 can float by buoyancy and can descend by weight. The upper end of the main body 21 is closed by a flat upper plate 22. The upper plate 22 is a disk-shaped plate with a diameter larger than the outer diameter of the main body 21, and protrudes outward from the main body 21. The portion of the upper plate 22 protruding from the main body 21 functions as a stopper that restricts the upward movement of the floating ring 40 (see FIG. 4).

[0018] The main body 21 has a plurality of intake ports 21a formed at intervals in the circumferential direction above half the total height of the main body 21. These intake ports 21a are located above the upper end of the motor casing 6. A filter 23 is attached to the outer peripheral surface of the upper part of the main body 21 so as to cover the intake ports 21a. This filter 23 has air and water permeability, and is a mesh-like structure that does not allow foreign objects such as leaves, tree branches, and ropes that may flow in when unexpected water flows into the building due to a tsunami or the like to pass through. The filter 23 may be attached to the inner peripheral surface of the upper part of the main body 21 as long as it hinders the up and down movement of the floating ring 40. The filter 23 may also be made of punching metal, and may be configured to prevent the passage of expected foreign objects.

[0019] The mounting portion 24 is formed of a straight pipe having a larger diameter than the main body portion 21, and is coaxially joined to the lower end of the main body portion 21 via an annular intermediate plate 25. The internal space of the mounting portion 24 communicates with the internal space of the main body portion 21. The intermediate plate 25 protrudes radially outward from the main body portion 21, and this protruding portion functions as a stopper that restricts the downward movement of the floating ring 40.

[0020] 2 and 3, the mounting portion 24 is attached to the motor casing 6 via an annular flange 26 so as to surround the protruding portion 6a of the motor casing 6. The flange 26 is attached to the motor casing 6 so as to surround the upper outer ends of the multiple air-cooling fins 6b. The inner diameter of the mounting portion 24 is equal to or larger than the inner diameter of the flange 26 and smaller than the outer diameter of the flange 26.

[0021] The lower end opening of the mounting portion 24 constitutes an exhaust port 24a that exhausts air inside the fan casing 20 to the outside. More specifically, the exhaust port 24a is defined by the inner circumferential surface of the flange 26 and the outer surface of the motor casing 6 including the air-cooling fins 6b, and is located below the upper end of the motor casing 6. The air inside the fan casing 20 that is exhausted from the exhaust port 24a passes between adjacent air-cooling fins 6b and is released to the atmosphere.

[0022] 2, the waterproof motor 30 is provided to rotate the blades 35, and is controlled by the control unit 45 shown in FIG. 1. The waterproof motor 30 is a low-output, highly watertight electric motor capable of rotating the unloaded blades 35, and can continue to operate even when exposed to the atmosphere. The waterproof motor 30 is attached between the intake port 21a and the exhaust port 24a in the main body 21 of the fan casing 20 via a mounting member 31 made of a roughly rectangular prism-shaped frame. The output shaft 30a of the waterproof motor 30 protrudes downward along the axis of the fan casing 20.

[0023] The blades 35 are provided to blow air from above to the waterproof motor 5. The blades 35 are attached to the output shaft 30a of the waterproof motor 30 so as not to rotate relative to the output shaft 30a of the waterproof motor 30, and are disposed between the intake port 21a and the exhaust port 24a in the main body 21 of the fan casing 20. The blades 35 are rotated by the waterproof motor 30, suck in air from the outside of the fan casing 20 through the intake port 21a, collide with the protruding portion 6a of the motor casing 6, and then exhaust the air from the exhaust port 24a, thereby cooling the internal mechanism of the waterproof motor 5 through the motor casing 6. The blades 35 of this embodiment are constituted by a propeller fan. However, the blades 35 may be an axial fan or a sirocco fan, and can be modified as necessary as long as the air sucked from the intake port 21a can be exhausted from the exhaust port 24a.

[0024] The floating ring 40 is provided to cover the intake port 21a of the fan casing 20 when submerged. The floating ring 40 is made of resin with a specific gravity smaller than that of water, and is cylindrical and surrounds the main body 21 of the fan casing 20. A gap as small as possible is secured between the inner peripheral surface of the floating ring 40 and the outer peripheral surface of the main body 21 within a range in which the floating ring 40 is allowed to move up and down. The vertical (axial) length of the floating ring 40 is a dimension that can completely cover the intake port 21 in the floating position shown in FIG. 4, that is, is equal to or larger than the vertical height of the intake port 21a, and is a dimension that can completely open the intake port 21 in the lowered position shown in FIG. 2.

[0025] When the fan casing 20 is submerged, the floating ring 40 moves linearly from the lowered position shown in Fig. 2 to the raised position shown in Fig. 4 due to buoyancy. In the raised position, the floating ring 40 covers the intake port 21a, thereby preventing foreign matter contained in the inflowing water from entering the fan casing 20 and adhering to the filter 23 to block the intake port 21a.

[0026] On the other hand, when the water level drops below the fan casing 20, the floating ring 40 moves directly from the floating position shown in Fig. 4 to the lowered position shown in Fig. 2 due to its own weight. In the lowered position, the floating ring 40 opens the intake port 21a, so that the rotation of the blades 35 allows air outside the fan casing 20 to be taken in and discharged from the exhaust port 24a, thereby cooling the waterproof motor 5.

[0027] 1, the control unit 45 is composed of one or more microcomputers and other electronic devices. The control unit 45 controls the water-resistant motor 5 and the waterproof motor 30 based on the detection results of two water level sensors 46A and 46B, for example.

[0028] The water level sensors 46A, 46B are provided to detect whether the device is submerged in water or exposed to air. The water level sensors 46A, 46B output a signal when they detect water, and do not output a signal when they do not detect water. The water level sensors 46A, 46B may be of a contact type or a non-contact type as long as they can detect water.

[0029] Water level sensor 46A is disposed in the suction tank. Only one water level sensor 46A may be used, or two or more may be used at different height positions. Only one water level sensor 46B is disposed at a height position corresponding to impeller 35 in fan casing 20. However, water level sensor 46B may be disposed in a pump chamber on the installation floor covering the suction tank, and may be disposed directly below impeller 35 at a position where it is possible to detect the state of impeller 35 just before it is immersed in water, that is, at a height position corresponding to impeller 35.

[0030] When control unit 45 determines based on the detection result of water level sensor 46A that water has accumulated in the water suction tank up to a predetermined water level, it starts operation of waterproof motor 5 to drain the water in the water suction tank, and when it determines that the water level in the water suction tank has dropped below the predetermined water level, it stops operation of waterproof motor 5. Furthermore, when control unit 45 is stopped, it also keeps waterproof motor 30 stopped, and while waterproof motor 5 is operating, it controls waterproof motor 30 as follows based on the detection result of water level sensor 46B.

[0031] When the control unit 45 determines that the blades 35 are not submerged in water based on the detection result of the water level sensor 46B, it starts the operation of the waterproof motor 30. This rotates the blades 35 to forcibly air-cool the waterproof motor 5. On the other hand, when the control unit 45 determines that the blades 35 are submerged in water based on the detection result of the water level sensor 46B, it continues the operation of the waterproof motor 5 but stops the waterproof motor 30. This cools the waterproof motor 5 with the water that has flowed in, while preventing overload of the waterproof motor 30 caused by rotating the blades 35 in water. Also, when the control unit 45 determines that the water level has dropped below the blades 35 based on the detection result of the water level sensor 46B, it resumes the operation of the waterproof motor 30 and air-cools the waterproof motor 5.

[0032] The cooling fan 10 configured in this manner has the following features.

[0033] A cooling unit is made up of a fan casing 20, a waterproof motor 30, and a cooling fan 10 equipped with blades 35. As a result, during normal operation of the waterproof motor 5 that is not submerged, the waterproof motor 5 can be reliably cooled by the rotation of the blades 35 by the waterproof motor 30. With this cooling fan 10, the attachment of the fan casing 20 to the waterproof motor 5 does not need to be liquid-tight, and no cooling medium needs to be enclosed. Therefore, the configuration can be simplified compared to when a cooling unit is made up of a jacket and a cooling medium.

[0034] The cooling fan 10 includes a floating ring 40 that can move by buoyancy from a lowered position where the intake port 21a is open to a raised position where the intake port 21a is covered. As a result, when the cooling fan 10 is submerged together with the waterproof motor 5, the floating ring 40 can cover the intake port 21a, preventing foreign matter that flows in with the water from blocking the intake port 21a. On the other hand, when the water level drops, the floating ring 40 also descends to open the intake port 21a, ensuring an air flow path when the cooling process of the waterproof motor 5 is resumed. Therefore, the cooling fan 10 can cool the waterproof motor 5 without the operator having to perform any return operation, ensuring the operation of the waterproof motor 5.

[0035] The cover member is made of a floating ring 40 made of resin with a specific gravity smaller than that of water, and surrounds the fan casing 20. This makes it possible to reliably switch the intake port 21a between an open state and a covered state with a simple structure.

[0036] The controller 45 stops the waterproof motor 30 when it determines that the blades 35 are submerged in water based on the detection result of the water level sensor 46. This prevents the waterproof motor 30 from being overloaded due to rotating the submerged blades 35. This prevents damage to the waterproof motor 30, so that the cooling process of the waterproof motor 5 can be reliably resumed when the water level drops.

[0037] Other embodiments and various modifications of the present invention will be described below, but in these descriptions, points that are not particularly mentioned are the same as those in the first embodiment. In the drawings referred to below, the same elements as those in the first embodiment are given the same reference numerals.

[0038] Second embodiment 5, the cooling fan 10 of the second embodiment differs from the cooling fan 10 of the first embodiment in that a floating ring 40 is arranged within the main body 21 of the fan casing 20 so as to be capable of linear movement.

[0039] The floating ring 40 is annular with an outer diameter smaller than the inner diameter of the main body 21 of the fan casing 20. Between the outer peripheral surface of the floating ring 40 and the inner peripheral surface of the main body 21, a gap as small as possible is secured within a range in which the floating ring 40 is allowed to move up and down.

[0040] In order to move the floating ring 40 up and down within the main body 21, the mounting member 31 of the waterproof motor 30 is attached to the upper plate 22, and a stopper 21b is provided within the main body 21. The stopper 21b has an annular shape and protrudes inward from the inner circumferential surface of the main body 21 so as to be located above the blades 35, and regulates the downward movement of the floating ring 30. The upward movement of the floating ring 30 is regulated by the upper plate 22, as in the first embodiment.

[0041] When the fan casing 20 is submerged, the floating ring 40 moves linearly from a lowered position shown by a solid line in Fig. 5 to a floating position shown by a dashed line in Fig. 5 due to buoyancy. In the floating position, the floating ring 40 covers the inside of the intake port 21a, thereby preventing foreign matter contained in the inflowing water from entering the fan casing 20 and suppressing blocking of the intake port 21a.

[0042] On the other hand, when the water level drops below the fan casing 20, the floating ring 40 moves directly from the floating position shown by the dashed line in Fig. 5 to the lowered position shown by the solid line in Fig. 5 due to its own weight. In the lowered position, the floating ring 40 opens the intake port 21a, so that the rotation of the blades 35 allows the air outside the fan casing 20 to be taken in and discharged from the exhaust port 24a, thereby cooling the waterproof motor 5.

[0043] Third embodiment 6, the cooling fan 10 of the third embodiment differs from the cooling fan 10 of the first embodiment in that a plurality of floating plates (cover members) 50 are arranged instead of the floating ring 40 shown in FIG.

[0044] The floating plate 50 is made of resin having a specific gravity smaller than water, and is provided for each of the plurality of intake ports 21a provided in the main body 21 of the fan casing 20. That is, when two intake ports 21a are provided in the cylindrical main body 21, two semi-cylindrical floating plates 50 are arranged. When three or more intake ports 21a are provided in the cylindrical main body 21, three or more fan-shaped floating plates 50 are arranged to correspond to the respective intake ports 21a. When the main body 21 is a polygonal tube having three or more side walls and the intake ports 21a are provided in each side wall, three or more flat floating plates 50 are arranged to correspond to the respective intake ports 21a. Each floating plate 50 is rotatably supported by a hinge connection portion 51 arranged below the intake ports 21a in the main body 21.

[0045] When the fan casing 20 is submerged, the floating plate 50 rotates due to buoyancy from a lowered position shown by a solid line in Fig. 6 to a raised position shown by a dashed line in Fig. 6. In the raised position, the floating plate 50 covers the intake port 21a, thereby preventing foreign matter contained in the flowing in water from entering the fan casing 20 and blocking the intake port 21a.

[0046] On the other hand, when the water level drops below the fan casing 20, the floating plate 50 rotates due to its own weight from the raised position shown by the dashed line in Fig. 6 to the lowered position shown by the solid line in Fig. 6. In the lowered position, the floating plate 50 opens the intake port 21a, so that the rotation of the blades 35 can take in air from outside the fan casing 20 and discharge it from the exhaust port 24a, thereby cooling the waterproof motor 5.

[0047] The cooling fan 10 of the second and third embodiments configured in this manner can achieve the same actions and effects as the cooling fan 10 of the first embodiment. Also, the intake port 21a can be reliably switched between an open state and a covered state with a simple configuration.

[0048] (Fourth embodiment) Referring to FIG. 7, the cooling fan 10 of the fourth embodiment differs from the cooling fan 10 of the first embodiment in that the main body 21 of the fan casing 20 is provided with an upper floating ring (upper cover member) 40 similar to that of the first embodiment that covers the intake port 21a, and the motor casing 6 is further provided with a lower floating ring (lower cover member) 53 that covers the exhaust port 24a.

[0049] The lower floating ring 53 is provided to cover the exhaust port 24a of the fan casing 20 when submerged. The lower floating ring 53 is made of resin with a smaller specific gravity than water, and is annular in shape surrounding the motor casing 6, which has a circular outer shape in a plan view. The downward movement of the lower floating ring 53 is regulated by a plurality of plate-like mounting portions 6c protruding from the motor casing 6. The upward movement of the lower floating ring 53 is regulated by a flange 26 attached to the motor casing 6.

[0050] 8, the inner diameter of the lower floating ring 53 is smaller than the diameter of a virtual circle (shown by a dashed line in FIG. 8) connecting the outer ends of the multiple air-cooling fins 6b of the motor casing 6, and the outer diameter of the lower floating ring 53 is larger. The lower floating ring 53 is provided with insertion grooves 53a corresponding to the multiple air-cooling fins 6b. Between the inner peripheral surface of the lower floating ring 53 including the insertion grooves 53a and the outer peripheral surface of the motor casing 6 including the air-cooling fins 6b, a gap as small as possible is secured within a range in which the lower floating ring 53 is allowed to move up and down. However, as long as it is possible to suppress the intrusion of foreign matter into the fan casing 20, the lower floating ring 53 may be formed of a ring body having an inner diameter slightly larger than the virtual circle connecting the outer ends of the multiple air-cooling fins 6b.

[0051] When the motor casing 6 is submerged, the lower floating ring 53 moves linearly from a lowered position shown by a solid line in Fig. 7 to a floating position shown by a dashed line in Fig. 7 due to buoyancy. In the floating position, the lower floating ring 53 covers the exhaust port 24a shown in Fig. 3, thereby preventing foreign matter contained in the inflowing water from entering the fan casing 20 and blocking the exhaust port 24a.

[0052] On the other hand, when the water level drops below the motor casing 6, the lower floating ring 53 moves directly from the floating position shown by the dashed line in Fig. 7 to the lowered position shown by the solid line in Fig. 7 due to its own weight. In the lowered position, the lower floating ring 53 opens the exhaust port 24a, so that the air inside the fan casing 20 can be exhausted by the rotation of the blades 35, and the waterproof motor 5 can be cooled.

[0053] The cooling fan 10 of the fourth embodiment configured in this manner can achieve the same actions and effects as the cooling fan 10 of the first embodiment. Moreover, when submerged, the exhaust port 24a can be covered by the lower floating ring 53, and when the water level drops, the lower floating ring 53 also descends to open the exhaust port 24a, ensuring an air flow path when the cooling process of the waterproof motor 5 is resumed. Therefore, the cooling fan 10 can reliably cool the waterproof motor 5 without the operator having to perform any resetting operation, and operation of the waterproof motor 5 can be guaranteed.

[0054] Fifth embodiment 9, the cooling fan 10 of the fifth embodiment differs from the cooling fan 10 of the first embodiment in that, instead of the floating ring 40 shown in FIG. 2, the fan casing 20 is entirely surrounded by a cover 55.

[0055] Specifically, in the fifth embodiment, a flexible cover 55 and a floating member 56 attached to the upper end of the cover 55 constitute a cover member.

[0056] Cover 55 is cylindrical with a diameter surrounding fan casing 20 and includes wavy bellows portion 55a for providing flexibility. The lower end of bellows portion 55a is fixed to the lower side of mounting portion 6c of motor casing 6. As shown by the dashed line in FIG. 9, when bellows portion 55a is in an expanded state, the upper end of cover 55 is located above upper plate 22 of fan casing 20.

[0057] The cover 55 is made of a vinyl sheet that does not have water permeability. However, the cover 55 may be made of a dustproof net that has a mesh shape that prevents possible foreign objects from passing through and has water permeability, and can be changed as necessary as long as it is a flexible cylindrical member that can prevent the passage of foreign objects contained in the inflowing water. In addition, the lower end of the cover 55 may be fixed to the lower end of the motor casing 6.

[0058] The floating members 56 are spherical members made of resin with a specific gravity smaller than that of water. The floating members 56 are attached to the upper end of the cover 55 by an attachment member (not shown), such as a round ring. The number of floating members 56 is set based on the buoyancy that allows the cover 55 to float with the inflowing water and expand from the contracted state (lowered position) shown by the solid line in Fig. 9 to the expanded state (floated position) shown by the dashed line in Fig. 9. In other words, the number of floating members 56 is set based on the weight of the cover 55 and the total buoyancy of the multiple floating members 56.

[0059] In this fifth embodiment, when the fan casing 20 is submerged, the buoyancy of the multiple floating members 56 causes the cover 55 to expand from the contracted state shown by the solid line in Fig. 9 to the expanded state shown by the dashed line in Fig. 9. At this time, the lower end of the cover 55 does not float up because it is fixed. In the expanded state, the cover 55 covers the exhaust port 24a and the intake port 21a, thereby preventing foreign matter contained in the flowing in water from entering the fan casing 20 and blocking the exhaust port 24a and the intake port 21a.

[0060] On the other hand, when the water level falls below the fan casing 20, the floating member 56 falls following the water level, and the cover 55 also retracts from the floated position shown by the dashed line in Fig. 9 to the lowered position shown by the solid line in Fig. 9. In the retracted position, the upper end of the cover 55 descends below the intake port 21a and the exhaust port 24a, and by opening these, the rotation of the blades 35 allows the air outside the fan casing 20 to be taken in and discharged from the exhaust port 24a, thereby cooling the waterproof motor 5.

[0061] The cooling fan 10 of the fifth embodiment thus configured can achieve the same action and effect as the cooling fan 10 of the first embodiment. Moreover, the cover member is composed of a cylindrical and flexible cover 55 and a floating member 56 made of resin having a specific gravity smaller than that of water. As a result, when the cooling fan 10 is submerged, the cover 55 can cover the intake port 21a and the exhaust port 24a via the floating member 56, so that the intake port 21a and the exhaust port 24a can be prevented from being blocked by foreign matter. On the other hand, when the water level drops, the cover 55 also descends via the floating member 56 to open the intake port 21a and the exhaust port 24a, so that an air flow path can be secured when the cooling process of the waterproof motor 5 is resumed. Therefore, the cooling fan 10 can cool the waterproof motor 5 without the operator performing any return operation, and the operation of the waterproof motor 5 can be guaranteed.

[0062] The present invention is not limited to the configurations of the above-described embodiments, and various modifications are possible.

[0063] For example, as long as the main body 21 of the fan casing 20 extends vertically from a raised position covering the intake port 21a to a lowered position opening the intake port 21a, the other portions may be inclined, bent, or curved. The main body 21 and the mounting portion 24 of the fan casing 20 may be made of a straight pipe of uniform diameter. The main body 21 and the mounting portion 24 of the fan casing 20 may be polygonal tubular.

[0064] The waterproof motor 30 described in the first embodiment shown in Fig. 2 and the third embodiment shown in Fig. 6 to the fifth embodiment shown in Fig. 9 may be attached to the upper plate 22 via a mounting member 31, as in the second embodiment shown in Fig. 5. Also, the main body of the waterproof motor 30 may be disposed outside the fan casing 20, as long as the output shaft 30a is disposed inside the fan casing 20 by penetration.

[0065] The cooling fan 10 of the second embodiment shown in FIG. 5 and the cooling fan 10 of the third embodiment shown in FIG. 6 may be configured to include a lower floating ring 53 that blocks the exhaust port 24a when submerged, similar to the cooling fan 10 of the fourth embodiment shown in FIG. 7.

[0066] The floating ring 40 of the first and second embodiments shown in Figures 2 and 6, the floating plate 50 of the third embodiment shown in Figure 6, the lower floating ring 53 of the fourth embodiment shown in Figure 7, and the floating member 56 of the fifth embodiment shown in Figure 9 may be made of wood, hollow metal, etc., and may be any structure having a specific gravity lower than that of water.

[0067] The cooling fan 10 of the present invention is not limited to being used in the waterproof motor 5 used in the vertical pump 1, but may also be used in objects to be cooled such as bearing units, reducers, speed increasers, and transmissions that may be submerged in water. [Explanation of symbols]

[0068] 1 Vertical pump 2 Discharge pipe 2a Motor mounting part 3 Rotation Axis 5. Water-resistant motor (object to be cooled) 6 Motor casing 6a Protrusion 6b Air cooling fin 6c Mounting part 7 Output shaft 10 Cooling fan (cooling unit) 20 Fan casing 21 Main body 21a Air intake 21b Stopper 22 Upper Board 23 Filters 24 Mounting part 24a Exhaust port 25 Intermediate Plate 26 Flange 30 Waterproof motor 30a Output shaft 31 Mounting material 35 Feather 40 Floating ring (cover member) 45 Control section 46A, 46B Water level sensor 50 Floating plate (cover member) 51 Hinge connection 53 Lower floating ring 53a Insertion groove 55 Cover (Cover material) 55a Bellows 56 Floating member (cover member)

Claims

1. a cylindrical casing having a main body portion extending in a vertical direction and a closed upper end, and an attachment portion connected to a lower end of the main body portion and attached to an object to be cooled, the cylindrical casing having an intake port formed at an upper portion of the main body portion and an exhaust port formed at the attachment portion; a waterproof motor attached to the casing; a blade disposed within the casing, the blade being rotated by the waterproof motor to suck in air through the intake port and exhaust the air through the exhaust port to cool the object to be cooled; a cover member that is movable by buoyancy from a descended position where the air intake port is open to a raised position where the air intake port is covered; Equipped with a cooling fan.

2. 2. The cooling fan according to claim 1, wherein the cover member is a structure having a specific gravity smaller than that of water and is configured by a floating ring surrounding the main body.

3. 2. The cooling fan according to claim 1, wherein the cover member is a structure having a specific gravity smaller than that of water, and is configured by a floating ring disposed within the main body portion so as to be capable of linear movement.

4. The air intake port is provided in two or more locations spaced apart from one another in a circumferential direction of the main body, 2. The cooling fan according to claim 1, wherein the cover member is a structure having a specific gravity smaller than that of water, and is constituted by a floating plate rotatably disposed below each of the two or more air intake ports.

5. 2. The cooling fan according to claim 1, further comprising a lower cover member movable by buoyancy from a lowered position in which the exhaust port is open to a raised position in which the exhaust port is covered.

6. The cover member is a cylindrical and flexible cover surrounding the casing; a floating member attached to an upper end of the cover and made of a structure having a specific gravity smaller than that of water; 2. The cooling fan according to claim 1, comprising:

7. A water level sensor attached at a position corresponding to the blade in the upward direction; a control unit that stops the waterproof motor when it is determined that the blade is submerged based on the detection result of the water level sensor; The cooling fan according to claim 1 , further comprising:

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