JP2005023897A - Blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blower for which gas leakage countermeasures can be taken without using sealing parts. <P>SOLUTION: An impeller 28 is rotatably arranged in a metal casing 12. The impeller 28 is rotated by a molded motor 40 mounted on the lower face side of the casing 12. In this case, a distribution space 42 is provided between the molded motor 40 and the casing 12 and a second air inlet 26 is provided around a rotating shaft 46 passing through the casing 12. Negative pressure is generated on the lower face side of the impeller 28 by the rotation of the impeller 28 to prevent gas leakage. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a blower, and more particularly to a combustion blower used for a boiler or the like.

  Various proposals have been made regarding the configuration of the blower (Patent Document 1).

  Among these blowers, a countermeasure against gas leak is indispensable for a blower for combustion incorporated in a boiler of the type that puts combustion gas into the suction port.

  A conventional structure of the blower 100 for combustion will be described with reference to FIG.

  FIG. 8 is a longitudinal sectional view of the blower 100 and an enlarged view of a part thereof.

  An impeller 104 is rotatably disposed inside the casing 102 of the blower 100. A gas suction port 106 is opened on the upper surface of the casing 102, and a discharge port (not shown) is opened on the peripheral surface thereof.

  A mold motor 108 is attached to the lower side of the casing 102, and the rotation shaft of the mold motor 108 is fixed to the impeller 104.

  As shown in the enlarged view of FIG. 8, a seal between the lower surface of the mold motor 108 and the casing 102 is sealed with an O-ring 110, and a bearing 112 on the upper surface side (load side) of the mold motor 108 is a rubber seal bearing. I have to.

Thereby, the gas leak from the through-hole 116 through which the rotating shaft 114 of the mold motor 108 penetrates the lower surface of the casing 102 can be prevented.
Japanese Patent Laid-Open No. 7-4382

  However, in the countermeasure against the gas leak in the conventional blower 100, the rubber of the O-ring 110 and the rubber seal bearing 112 may pass through the gas, and the gas may leak to the outside of the casing 102.

  In addition, if forgetting to install seal parts such as the O-ring 110, gas leakage may occur.

  Therefore, in view of the above problems, the present invention provides a blower that can take measures against gas leakage without using a sealing component.

  According to the first aspect of the present invention, an impeller is rotatably disposed inside the casing, a gas suction port is opened on one side surface of the casing, a motor is disposed outside the other side surface of the casing, In the blower in which a discharge port is opened on the surface and the rotation shaft of the motor passes through the other side surface of the casing and is fixed to the impeller, a second suction port is formed around the rotation shaft on the other side surface of the casing. Is a blower characterized by opening.

  The invention according to claim 2 is the blower according to claim 1, wherein a circulation space is provided between the other side surface of the casing and the motor, and air flows from the circulation space into the second suction port. .

  A third aspect of the present invention is the blower according to the first aspect, wherein a plurality of auxiliary blades are provided around the rotating shaft on the other side surface of the impeller.

  The invention according to claim 4 is the blower according to claim 1, wherein a plurality of through holes are provided around the rotation shaft on the other side surface of the impeller.

  A fifth aspect of the present invention is the blower according to the first aspect, wherein the motor is a molded motor.

  A sixth aspect of the present invention is the blower according to the first aspect, wherein the motor is a brushless DC motor.

  The invention of claim 7 is the blower according to at least one of claims 1 to 6, wherein the blower is a combustion blower used for a boiler, and the gas is a combustion gas. is there.

  In the blower according to the first aspect, the second suction port is opened around the rotation shaft on the other side surface of the casing. For this reason, when the impeller rotates, the periphery of the rotation shaft becomes negative pressure, and air outside the casing can be sucked from the second suction port. That is, a negative pressure effect occurs. Therefore, no gas leak occurs from the periphery of the rotating shaft during the rotation of the impeller.

  Further, it is not necessary to attach seal parts as in the prior art, the cost is reduced, and the assembly workability is improved.

  In the blower according to claim 2, a circulation space is provided between the other side surface of the casing and the motor, and air flows from the circulation space to the second suction port, thereby further promoting the negative pressure effect. Can be prevented from leaking.

  In the blower according to claim 3, by providing a plurality of auxiliary blades around the rotation shaft on the other side of the impeller, air can be sucked more from the second suction port, and the negative pressure effect is enhanced. . Therefore, gas leak from the casing can be prevented. Moreover, since this auxiliary blade also serves as a reinforcing rib in the impeller, the strength of the impeller is also improved.

  In the blower of claim 4, by providing a plurality of flow through holes around the rotation shaft on the other side of the impeller, the vicinity of the rotation shaft becomes negative pressure, and air is more reliably sucked from the second suction port. Can increase the negative pressure effect.

  In the blower of claim 5, since the motor is a molded motor, no gas leak occurs through the frame of the motor.

  In the blower according to the sixth aspect, since the motor is a brushless DC motor, no spark or the like is generated by the brush, and there is an explosion-proof effect.

  In the blower of claim 7, as described above, the blower of claims 1 to 6 can prevent gas leakage, and thus is suitable for a combustion blower used for a boiler using combustion gas.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  The blower 10 according to the first embodiment relates to a combustion blower incorporated in a boiler.

(1) Structure of the blower 10 The structure of the blower 10 will be described with reference to FIGS.

  The casing 12 of the blower 10 has a substantially disk shape, and includes a casing main body 14 that forms a peripheral surface and a lower surface of the casing 12, and a lid body 16 that covers the casing main body 14. Both the casing main body 14 and the lid body 16 are made of metal. A circular suction port 18 for sucking combustion gas is opened on the top surface of the lid 16, that is, the casing 12. Further, a gas discharge port 20 is opened on the peripheral surface of the casing body 14. The discharge port 20 is provided with a linear wall surface 22 extending from the circular peripheral surface of the casing body 14 and provided at the tip thereof. A sealing member 24 made of an O-ring for preventing gas leakage is provided between the lid body 16 and the upper surface edge of the casing body 14, and the lid body 16 and the casing body 14 are screwed together. Further, a second suction port 26 described later opens on the lower surface of the casing body 14, that is, the lower surface of the casing 12.

  Inside the casing 12, an impeller 28 is provided for discharging the combustion gas flowing in from the suction port 18 on the upper surface from the discharge port 20 on the peripheral surface. The impeller 28 has a circular bottom plate 30 and a boss 32 projects from the center thereof. A plurality of blades 34 are erected from the upper surface of the lower surface plate 30, and a donut-shaped upper surface plate 36 is attached to the upper end portion of the blades 34. The gas sucked from the circular opening 38 at the center of the upper surface plate 36 is blown out from the outer end of the blade 34.

  A molded motor 40 is attached below the casing 12. Between the upper surface (load side) of the mold motor 40 and the lower surface of the casing 12, a circulation space 42, which is a gap through which air flows, is provided. In order to form the circulation space 42, the mold motor 40 is screwed to the lower surface of the casing 12 through the gap forming member 44.

  The rotating shaft 46 of the mold motor 40 passes through the second suction port 26 on the lower surface of the casing 12 and is inserted and fixed to the boss 32 of the impeller 28 from the lower surface side. As shown in the enlarged view of FIG. 1, the second suction port 26 is formed to be larger than the rotation shaft 46 and larger than the protrusion 48 on the upper surface side of the mold motor 40. A space for air to flow is formed between the air inlet 26 and the air inlet 26.

  The mold motor 40 is a brushless DC motor, and a stator (not shown) is molded with a mold resin to form a frame 50. At the time of molding, the wiring board 52 having a drive circuit for driving the brushless DC motor and the upper bracket 54 are simultaneously molded on the upper surface side of the mold motor 40 and embedded in the frame 50. A protrusion 48 protrudes from the upper part of the frame 50 in order to bury the upper bracket 54.

  A rubber seal bearing 56 is attached to the inner peripheral side of the upper bracket 54, and a rotor 58 is rotatably attached to the bearing 56. Although not shown in FIG. 1, the lower surface side of the rotor 58 is also attached to the bearing via a bracket.

(2) Operation of the blower 10 The operation state of the blower 10 having the above configuration will be described with reference to FIG.

  When the mold motor 40 rotates and the impeller 28 rotates, gas is sucked from the suction port 18 and discharged from the discharge port 20.

  In this case, due to the rotation of the impeller 28, the lower surface side of the impeller 28 becomes negative pressure, and air is sucked from the second suction port 26. In this case, since there is a circulation space 42 between the mold motor 40 and the casing 12, air surely flows through the circulation space 42 to the second suction port 26 and is sucked. When air is sucked in from the second suction port 26 and enters the inside of the casing 12, passes through the lower surface side of the impeller 28 and reaches the discharge port 20, gas flows from the second suction port 26 to the casing by the air flow. Gas leakage can be prevented without flowing out to the outside.

  With the above configuration, since it is not necessary to provide a seal member between the mold motor 40 and the casing 12 as in the prior art, the assembling workability is improved and the cost is reduced.

  Further, since the motor that rotates the impeller 28 is the mold motor 40, no gas leak occurs from the mold motor 40. Since the mold motor 40 is a brushless DC motor, there is no possibility that sparks are generated from the brush and the gas is ignited. Since there is the wiring board 52 inside the mold motor 40, it is possible to prevent ignition of the gas by the components on the wiring board.

(Second Embodiment)
Next, the blower 10 of the second embodiment will be described based on FIG.

  The difference between the second embodiment and the blower 10 of the first embodiment is the structure of the lower surface of the impeller 28.

  That is, the auxiliary blades 60 project downward from the lower surface of the impeller 28 in the blower 10 of the second embodiment. Further, the auxiliary blade 60 is disposed on the outer peripheral portion of the rotation shaft 46 so as to surround the rotation shaft 46.

  By providing the auxiliary blade 60 in this way, when the impeller 28 rotates, the negative pressure on the lower surface side of the impeller 28 increases, and the amount of air sucked from the second suction port 26 increases. Gas leak can be surely prevented.

  Further, the plurality of auxiliary blades 60 also serve as reinforcing ribs for the lower surface plate 30 of the impeller 28, and the strength of the impeller 28 is improved.

(Third embodiment)
Next, the air blower 10 of 3rd Embodiment is demonstrated based on FIG.

  The difference between the third embodiment and the blower 10 of the first embodiment is the structure of the lower surface plate 30 of the impeller 28.

  A plurality of flow through holes 62 are opened in the outer peripheral side portion of the boss 32 in the lower surface plate 30 of the impeller 28 in the third embodiment.

  As shown in FIG. 7, the plurality of flow through holes 62 have large diameter flow through holes 62 around the small diameter flow through holes 62.

  By providing a plurality of flow through holes 62 in this way, air is sucked from the flow through holes 62 when the impeller 28 rotates, and the negative pressure effect on the lower surface side of the impeller 28 is further increased. Therefore, the amount of air sucked from the second suction port 26 is increased, and gas leakage can be prevented more reliably.

  In addition, this circulation through-hole 62 can improve a negative pressure effect more by increasing the number.

(Example of change)
The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, there are the following modifications.

  In the above embodiment, the molded motor 40 is used as the motor. However, a motor having a steel plate frame may be used instead.

(Modification 2)
In the above embodiment, a brushless DC motor is used, but other induction motors and synchronous motors may be used.

(Modification 3)
By combining the second and third embodiments, the auxiliary blade 60 may be provided on the bottom plate 30 of the impeller 28, and the flow through hole 62 may be provided on the bottom plate.

  Since the blower of the present invention can prevent gas leakage, it is suitable as a combustion blower incorporated in a boiler.

  In addition to this, it is suitable for a blower for the purpose of gas leak and the like.

It is the longitudinal cross-sectional view of the air blower of 1st Embodiment, and the one part enlarged view. It is a top view of an air blower similarly. It is a bottom view of an air blower similarly. It is a front view of a fan similarly. It is a side view of a fan similarly. It is the longitudinal cross-sectional view and enlarged view of the air blower of 2nd Embodiment. It is a partial cutaway perspective view of the impeller in the air blower of 3rd Embodiment. It is the longitudinal cross-sectional view and enlarged view of the conventional air blower.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Blower 12 Casing 18 Suction port 20 Discharge port 26 2nd suction port 28 Impeller 30 Bottom plate 32 Boss 34 Blade 40 Mold motor 42 Distribution space 46 Rotating shaft 60 Auxiliary blade 62 Distribution through-hole

Claims (7)

An impeller is rotatably arranged inside the casing, a gas suction port is opened on one side of the casing, a motor is arranged outside the other side of the casing, and a discharge port is opened on the peripheral surface of the casing. In the blower in which the rotating shaft of the motor passes through the other side surface of the casing and is fixed to the impeller.
A blower characterized in that a second suction port opens around the rotating shaft on the other side surface of the casing. The blower according to claim 1, wherein a circulation space is provided between the other side surface of the casing and the motor, and air flows from the circulation space to the second suction port. The blower according to claim 1, wherein a plurality of auxiliary blades are provided around the rotation shaft on the other side surface of the impeller. The blower according to claim 1, wherein a plurality of flow through holes are provided around the rotation shaft on the other side surface of the impeller. The blower according to claim 1, wherein the motor is a molded motor. The blower according to claim 1, wherein the motor is a brushless DC motor. The blower according to at least one of claims 1 to 6, wherein the blower is a combustion blower used for a boiler, and the gas is a combustion gas.

Images