JP2000179495A - Electric fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively seal a seal member for sealing a space between a centrifugal fan and a fan casing by retaining it by a seal retaining member. SOLUTION: This electric fan is constituted of a fan casing 15 mounted to a housing of a motor and formed so as to cover a centrifugal fan and a diffuser; a curved portion 23 circularly formed on the suction hole 16 of the fan casing coaxially to a suction hole of the centrifugal fan; a seal member 20 slidably contacted with the suction hole of the centrifugal fan in the state that it is retained by a seal retaining member 21; and a seal presser member 25 mounted to the fan casing and pressing the seal member 20. The seal retaining member 21 is provided with a recess groove 22 engaged with the seal member 20 and engagement-retains the seal member 20 on the curved portion 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electric blower,
In particular, the present invention relates to an electric blower provided with a seal member for sealing between a centrifugal fan and a fan casing that covers the centrifugal fan.

[0002]

2. Description of the Related Art FIG. 5 is a view showing the internal structure of a conventional electric blower.

In the drawing, reference numeral 1 denotes an electric blower using a commutator motor or the like, 2 denotes a motor housing, 3 denotes a stator fixed to the housing 2, 4a denotes a bearing provided in the housing 2, and 4b denotes an end bracket. Bearing 5, bearing 4
a and 4b, the rotating shaft of the electric motor, 6 a rotor fixed to the rotating shaft 5, 7 a commutator fixed to the rotating shaft 5, 8 a brush for making electrical connection with the commutator, 9 a brush 8 Is a holder for holding the housing 2
Fixed to. Reference numeral 10 denotes a spring for pressing the brush 8 against the commutator 7, and reference numeral 11 denotes a lead wire electrically connected to the brush 8 for connecting the brush 8 to an external electrode.

[0004] Reference numeral 12 denotes a centrifugal fan fixed to one end of the rotating shaft 5, 13 denotes a diffuser for reducing the flow rate of the air flow from the centrifugal fan to recover the pressure, and 14 denotes a diffuser integrally formed with the diffuser. A return guide 15 for guiding the flow into the motor is a fan casing that covers the centrifugal fan 12 and the diffuser 13. The fan casing 15 is assembled by press-fitting the housing of the electric motor to a position where the fan casing 15 comes into contact with the upper surface of the diffuser 13, and holds the diffuser. 16 is an intake hole of the fan casing 15, 17 is an end bracket for holding the bearing 4b, 18
Is a screw for fixing the centrifugal fan 12 to the rotating shaft 5, and 19 is an intake hole of the centrifugal fan 12. 200 is a seal member attached to the fan casing 15.

When the electric motor is driven, the centrifugal fan directly connected to the rotating shaft of the electric motor starts to rotate, and the air flowing in from the intake hole 16 is given dynamic pressure by the centrifugal fan and flows into the diffuser 13. The air whose flow velocity has been reduced by the diffuser to recover the static pressure is further bent in the flow path direction by the return guide 14, guided into the electric motor, cooled, and then discharged to the outside.

A part of the inflow air given the dynamic pressure by the centrifugal fan 12 flows between the centrifugal fan 12 and the fan casing 15 without flowing into the diffuser, and returns to the intake hole 19 of the centrifugal fan 12 again. Creates circulating flow in the path. The generation of this circulating flow causes a reduction in the efficiency of the electric blower.

The fan casing 15 is generally formed into a complicated shape by pressing, and the centrifugal fan 12 is formed by assembling a large number of blades having a complicated shape with a thin plate of aluminum or the like. For this reason, in the fitting portion between the intake hole 16 of the fan casing and the intake hole 19 of the centrifugal fan, the roundness is deviated due to the variation in press working, or the centrifugal fan shaft and the fan casing shaft when the electric blower is assembled. And a gap is created between the fan casing 15 and the intake hole of the centrifugal fan 12.

As means for closing the gap and preventing circulating flow, for example, Japanese Unexamined Patent Publication (Kokai) No. 7-18992 discloses a method in which a sealing material excellent in sliding cutability is attached to an intake hole of a fan casing, and a centrifugal fan has an intake hole. There is disclosed a technique of rubbing and fitting so that the parts bite.

[0009]

In the technique disclosed in the above publication, the seal member is required to have good slidability and good machinability at the time of rubbing. Materials must be plastic.
For this reason, if an unreasonable external force is applied during the assembling work, elongation or deformation may occur, and a gap or a turn may be generated in the fitting attachment portion with the fan casing after assembling. Further, if the coaxiality between the seal member and the centrifugal fan intake hole is lost due to deformation or displacement, the sliding fitting portion is disengaged and a gap is generated.

Further, when the seal member is mounted on the fan casing, the seal member is disposed on the fan casing, a holding member is disposed so as to sandwich the seal member, and fixed to the fan casing by means such as spot welding. Will be. In such an attaching method, it is difficult to position the seal member and the pressing member, and it is necessary to perform an operation so as not to deform the seal member, and the workability is deteriorated.

The present invention has been made in view of the above-mentioned various problems, and provides an electric blower to which a seal member capable of effectively sealing a space between a centrifugal fan and a fan casing covering the centrifugal fan can be easily attached. I do.

[0012]

The present invention employs the following means in order to solve the above-mentioned problems.

A centrifugal fan attached to a rotating shaft of the electric motor, a diffuser arranged on the outer periphery of the centrifugal fan, a fan casing attached to a housing of the electric motor and formed to cover the centrifugal fan and the diffuser; A curved portion formed in an annular shape coaxially with the intake hole of the centrifugal fan, a seal holding member attached to the fan casing and holding a seal member for sealing between the fan casing and the intake hole of the centrifugal fan. An electric blower comprising: a seal member slidably in contact with an intake hole of the centrifugal fan while being held by the seal holding member; and a seal pressing member attached to the fan casing and pressing the seal member. The holding member has a concave groove for fitting the seal member, One characterized by being fitted and held in the curved portion.

[0014] In the electric blower, the inner diameter of the centrifugal fan side end of the inner diameter side wall of the seal holding member may be:
It is characterized in that it is set substantially equal to the inner diameter of the fan casing.

Further, in the electric blower, the seal holding member is made of a thermoplastic resin.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing the internal structure of the electric blower according to the present embodiment, FIG. 2 is a detailed perspective sectional view of a seal portion of the electric blower according to the present embodiment, and FIG. 3 is a detailed sectional view of the seal portion.

In these figures, reference numeral 20 denotes a sealing member,
Reference numeral 21 denotes a seal holding member that fits and holds the seal member 20, 21a denotes an inner peripheral side wall of the seal member, and 21b denotes an outer peripheral side wall.

Reference numeral 22 denotes a concave groove formed by the side walls 21a and 21b, which is formed in a shape in which the seal member 20 fits exactly.

Reference numeral 23 denotes the intake hole 1 of the fan casing 15.
6 is a curved portion formed in an annular shape coaxially with the intake hole of the centrifugal fan, and the curved portion 23 has a bell mouth shape in cross section as shown in FIG.

The upper surface of the seal holding member 21 has a semicircular convex cross section, and is fitted coaxially with the curved portion 16 having a bell mouth cross section to be positioned coaxially.

Reference numeral 24 denotes a fitting groove for a centrifugal fan formed in the seal member 21, and reference numeral 25 denotes a pressing member for pressing and fixing the seal member 20, and the pressing member 25 is attached to the fan casing by welding or the like.

In the figure, the same parts as those shown in FIG. 5 are denoted by the same reference numerals, and the description thereof will be omitted.

According to the present embodiment, as shown in FIG.
The seal member 20 is sandwiched and held in a concave portion 22 formed by the side walls 21a and 21b. Therefore, when the centrifugal fan and the fan casing are assembled and the tip of the intake hole 19 of the centrifugal fan 12 and the sealing member are slid and slid, the centrifugal fan bites into the sealing member and tries to spread out the sealing member. The shape is preserved. Therefore, the fitting groove 24 after the centrifugal fan bites into it.
Does not collapse, and a stable sealing effect can be obtained.

Since the pressing member 25 is held between the fan casing 15 and the fan casing 15 so as to press the seal member 20, the pressing member 25 is located between the fan casing 15 and the seal holding member 21 and between the seal holding member 21 and the seal member 20. Airtightness is ensured.

Prior to this assembly, the assembly of the seal member 20 to the seal holding member 21 can be performed in advance as a separate operation. Therefore, stable handling is possible without deforming the seal member 20 in subsequent handling.

As shown in FIG. 3, the inner diameter of the side wall 21a on the inner diameter side of the seal holding member 21 is
By matching the inner diameter of the intake hole 16 with the inner diameter of step 5, the step δ1 can be eliminated, and separation of the air flow and increase in loss due to turbulence can be prevented.

The side wall 2 on the inner diameter side of the seal holding portion 21
Step δ between the inner diameter of the centrifugal fan 12 and the inner diameter of the centrifugal fan 12
2 also causes turbulence losses. This loss can be reduced by making the tip of the side wall 21a smooth and thin as a slope or a curved surface.

Further, if the seal holding member 21 is formed of a thermoplastic resin or the like, even if the outer diameter of the side wall 21a is increased to a value close to the inner diameter of the intake hole 19 of the centrifugal fan 12, non-contact fitting is achieved by rubbing. It becomes possible to do. That is, even if the seal holding member 21 and the centrifugal fan 12 come into contact with each other, the seal holding member made of a thermoplastic resin is softened by frictional heat, and non-contact fitting is obtained on the sliding surfaces. Therefore, the thickness of the side wall 21a can be reduced as much as possible, and the loss reduction effect can be increased.

FIG. 4A is a diagram showing another example of the structure of the curved portion formed in the intake hole of the fan casing in a ring shape coaxially with the intake hole of the centrifugal fan.

In the drawing, reference numeral 151 denotes a fan casing, and the curved portion 23 of the fan casing 151 has a U-shaped cross section as shown in FIG. 4A. 25
1 is a seal holding member. Also, the seal holding member 21
Has a rectangular cross section that matches the cross section of the curved portion. In the figure, the same parts as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

Even with such a cross-sectional shape, the seal holding member 21 can be coaxially positioned by fitting into the curved portion of the fan casing 151.

FIG. 4B shows a state in which an intake hole of a fan casing is provided.
It is a figure which shows another structural example of the curved part formed in the annular shape coaxially with the intake hole of a centrifugal fan.

In the drawing, reference numeral 152 denotes a fan casing, and the curved portion 23 of the fan casing 152 has a key-shaped cross section as shown in FIG. 3B. 251 is a seal holding member. The seal holding member 21 has a rectangular cross section that matches the cross section of the curved portion. In the figure, the same parts as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

Even with such a cross-sectional shape, the seal holding member 21 can be coaxially positioned by fitting into the curved portion of the fan casing 152.

[0035]

According to the present invention, since the seal member for sealing between the centrifugal fan and the fan casing covering the centrifugal fan is held by the seal holding member to prevent the seal member from being deformed and turned up, the centrifugal fan is discharged from the centrifugal fan. A high-efficiency electric blower can be obtained by preventing circulation of the air flow.

Further, the seal member and the seal holding member can be assembled in advance, and the seal holding member is positioned by the curved portion formed on the casing, so that the assembling operation to the fan casing can be easily performed. Can be. In addition, the workability can be improved without causing deformation or turning of the seal member.

[Brief description of the drawings]

FIG. 1 is a diagram showing an internal structure of an electric blower according to an embodiment of the present invention.

FIG. 2 is a detailed perspective sectional view of a seal portion of the electric blower.

FIG. 3 is a detailed sectional view of a seal portion of the electric blower.

FIG. 4 is a diagram showing another example of the structure of the curved portion of the fan casing.

FIG. 5 is a view showing the internal structure of a conventional electric blower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric blower 2 Housing 3 Stator 4a, 4b Bearing 5 Rotating shaft 6 Stator 7 Commutator 8 Brush 9 Holder 10 Spring 11 Lead wire 12 Centrifugal fan 13 Diffuser 14 Return guide 15, 151, 152 Fan casing 16 Intake hole 17 End Bracket 18 Screw 19 Intake hole 20 Seal member 21 Seal holding member 22 Concave groove 23 Curved portion 24 Fitting groove 25, 251, 252 Holding member

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuhiro Akoshima 1-1-1, Higashitagacho, Hitachi City, Ibaraki Prefecture F-term (reference) 3H022 AA02 BA02 CA22 CA48 CA54 DA07 DA08 3H034 AA02 AA11 BB02 BB06 BB20 CC04 DD02 DD24 DD28 EE05 EE09 EE13 EE18

Claims (3)

[Claims] A centrifugal fan attached to a rotating shaft of an electric motor and a diffuser arranged on the outer periphery of the centrifugal fan; a fan casing attached to a housing of the electric motor and formed to cover the centrifugal fan and the diffuser; A curved portion formed in a circular shape coaxially with the intake hole of the centrifugal fan at an intake hole portion of the fan casing; and a seal attached to the fan casing and holding a seal member for sealing between the fan casing and the intake hole of the centrifugal fan. In an electric blower comprising: a holding member; a sealing member that is slidably in contact with an intake hole of the centrifugal fan while being held by the seal holding member; and a seal holding member that is attached to the fan casing and presses the sealing member. The seal holding member has a groove for fitting the seal member. And an electric blower fitted and held in the bending portion. 2. The electric blower according to claim 1, wherein an inner diameter of an end of the inner wall of the seal holding member on the side of the centrifugal fan is set substantially equal to an inner diameter of the fan casing. 3. The electric blower according to claim 1, wherein the seal holding member is made of a thermoplastic resin.