JP2003343483A - Electric blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric blower with improved suction work without enlarging the diameter of a fan. <P>SOLUTION: In the electric blower equipped with the fan fixed to the rotating shaft of the motor, the fan is equipped with a suction port at the central part and an exhaust port at the outer peripheral part by a disk-like front shroud and a rear shroud having a plurality of fan blades between them. An annular circular part in which each outer peripheral end of the fan blade is inscribed, is provided at the outer peripheral part of the front shroud forming a part of the exhaust port. Air current sucked from the suction port and sent in the outer peripheral direction by the fan blade is changed by the circular part in direction and exhausted from the exhaust port. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blower that enhances the suction force of a fan rotating by an electric motor and allows the sucked air to efficiently flow into the electric motor.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, an electric blower 101 of this type has a front opening 102 and a rear opening 10.
In the bottomed cylindrical body case 104 having the
Electric motor 10 accommodating a motor body 106 having
Equipped with 7. A fan 108 fixed to the end of the rotary shaft 105 and rotated is provided on the front opening side of the electric motor 107, and a fan cover 110 having an intake port 109 at substantially the center so as to cover the fan 108 is provided. It is fitted and integrally attached to the outer periphery of the flange portion of the body case 104 of the electric motor 107. Also, the fan 108
A substantially disk-shaped diffuser 111 having a plurality of rectifying air passages for adjusting the flow of air is provided in the rear of the diffuser 111, and the diffuser 111 rectifies the air flow generated by the fan 108 to the inside of the body case 104. The airflow cools the motor main body 106 and exhausts it from the rear opening 103 of the body case 104.

The fan 108 has a circular inlet 1 at the center.
Slightly curved disc-shaped front shroud 11 with 12
3 and a disc-shaped rear surface shroud 115 having a mounting hole 114 at the center, a plurality of spirally-shaped spiral shrouds are provided at equal intervals from the vicinity of the suction port 112 toward the outer circumferences of both shrouds 113, 115. The fan blades 116 are provided. The outer diameters of both shrouds 113 and 115 are almost the same,
The outer peripheral surface formed between them is a plurality of outlets 117 partitioned by fan blades 116 at equal intervals. The discharge port 117 faces the annular space 118 surrounded by the inner peripheral surface of the fan cover 110. The fan 108 includes a sleeve 119 fitted to the rotating shaft 105 and the rotating shaft 1
The hexagonal nut 121 fixed to the threaded portion 120 formed at one end which is the front side of 05, the mounting hole 114 portion of the rear shroud 115 is washer 122, 12
It is sandwiched via 2 and is fixed to the rotary shaft 105.

Next, a case where the conventional electric blower 101 is driven will be described. The rotation of the rotary shaft 105 of the motor body 106 rotates the fan 108 fixed to the rotary shaft 105, and the action of the fan blades 116 causes the suction port 1 to pass through the intake port 109 of the fan cover 110.
The air sucked from 12 is discharged to the outlet 117 of the fan 108.
Are discharged into the annular space 118 of the fan cover 110. Then, this air is bent at a substantially right angle by the inner peripheral surface of the fan cover 110 fixed to the body case 104, and flows into the inlet of the outer peripheral portion of the diffuser 111.
The motor main body 106 is cooled until it passes through the rectifying air passage in the diffuser 111, flows into the periphery of the motor main body 106, and is exhausted to the outside.

[0005]

In the above prior art, if the outer diameter of the electric blower is reduced to meet the needs of downsizing the electric blower, the outer diameter of the fan is also reduced and the air volume is reduced. Therefore, if the number of rotations is increased to increase the air volume, problems such as a decrease in life and an increase in noise and vibration will occur.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electric blower in which the suction power is improved while the overall size is reduced.

[0007]

An electric blower according to claim 1, wherein the electric blower includes a fan fixed to a rotating shaft of the electric motor, wherein the fan includes a rear shroud fixed to the rotating shaft. The front shroud has a plurality of fan blades arranged and fixed between the rear shroud and the front shroud.
An annular arc-shaped portion in which each outer peripheral portion of the fan blade is inscribed is provided on the outer peripheral portion, and an outlet is formed by the end portion of the arc-shaped portion and the outer peripheral portion of the rear surface shroud. The airflow that is sucked from the suction port of the front shroud and guided to the outer peripheral portion of the front shroud is redirected by the arcuate portion and is exhausted rearward from the discharge port.

As a result, air is sucked from the suction port of the fan and sent in the radial direction by the fan blades, and the outer peripheral portions of both shrouds are redirected to be exhausted rearward from the discharge port which is parallel to the rotation axis of the fan. By doing so, the fan blades can be provided longer without increasing the outer diameters of the electric blower and the fan, the air volume or the suction force can be increased, and the suction power can be increased.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A configuration of an electric blower according to an embodiment of the present invention will be described below with reference to the drawings.

1 and 2, reference numeral 1 denotes an electric blower for an electric vacuum cleaner, for example, and the electric blower 1 has an electric motor 2. The electric motor 2 has a substantially cylindrical body case 3 made by processing a metal plate, and a motor body 4 is built inside the body case 3. The body case 3 can also be formed into a substantially rectangular tubular shape.

The body case 3 can also be formed by a lattice-shaped frame body having a large number of openings and having an overall shape of a cylinder or a square pole. Further, when the body case 3 has a shape capable of reducing the weight, it is possible to use only a rectangular frame body.

The body case 3 is formed with an opening 5 in the front portion in the axial direction, and a flange portion 6 having a substantially L-shaped cross section which projects around the opening 5 in the outer peripheral direction. Is bent and formed. Also, this body case 3
The rear end surface which is the other end in the axial direction of is closed by the rear plate portion 7 to have a bottomed cylindrical shape, and the central portion of the rear plate portion 7 projects rearward in a substantially cylindrical shape to form an inner circumference. A bearing accommodating portion 9 that accommodates the bearing 8 is integrally provided on the surface side.

Further, a pair of air outlets 11 are formed on the peripheral surface near the rear of the body case 3.

At the front portion of the body case 3, a long plate-shaped bridge portion 12 is attached by a screw 13 at its end so as to bridge the body case 3 in the radial direction and cover a part of the opening 5. Has been. A bearing portion 15 is provided at a substantially central portion of the bridge portion 12 so as to project forward in a substantially cylindrical shape, accommodate the bearing 8 on the inner peripheral side, and open a through hole 14 at a substantially central portion. It should be noted that, of the openings 5 of the body case 3, the portion not covered by the bridge portion 12 is the ventilation port 1
It becomes 6.

On the other hand, the motor main body 4 has a stator 18 composed of a core and windings fixed to the body case 3, and a rotor 19 arranged inside the stator 18. . The rotor 19 is disposed in the body case 3 with both ends of a rotary shaft 20 provided at its axis being rotatably supported by the bearings 8 and 8.

These bearings 8, 8 are bearings having a large number of steel balls or conical rollers, and at least the bearing 8 housed in the bearing portion 15 can withstand the thrust in the axial direction acting on the rotary shaft 20. It is a thrust bearing.

Further, a pair of brush mechanisms 22 are fixed to the body case 3 by screws 13 so as to partially project from the outer peripheral surface. Each of the brush mechanisms 22 includes a carbon brush 24 that is in sliding contact with a commutator 23 provided on the rotor 19, and a brush holder 25 that holds the carbon brush 24. And the carbon brush 24
Is pressed by the brush holder 25 and slidably contacts the commutator 23, whereby the carbon brush 24 and the commutator 23 are electrically connected to each other.

On the other hand, on the front side of the bridge portion 12, a diffuser 30 made of plastic is fixed to the bridge 12 by screws 13. Further, a fan 31 is arranged in front of the diffuser 30. The fan 31 is a centrifugal fan, and has a mounting hole 32 that fits into the rotary shaft 20 at the center thereof.
Of the washer 36, 36 by means of the sleeve 33 provided on the diffuser 30 side and the hexagonal nut 35 screwed to the threaded portion 34 formed at one end which is the front side of the rotary shaft 20.
It is sandwiched between the motor main body 4 and the rotor 19 and is fixed to the rotary shaft 20.

Further, as shown in FIGS. 1, 3 and 4, the diffuser 30 has a substantially disk-shaped disc portion 38 which opens a substantially circular through hole 37 at a substantially center thereof, and the through hole 37. The bearing portion 15 of the bridge portion 12 is fitted and inserted therein. A plurality of substantially L-shaped notches 39 are formed at equal intervals on the outer peripheral edge of the disc portion 38 so as to gradually widen toward the center side along the circumferential direction. The L-shaped peripheral edge of the cutout 39 is provided with slanted inner edges 39a, 39b for reducing airflow resistance.

Further, as shown in FIG. 4, the widthwise edge of the bridge portion 12 engages with the back surface of the disc portion 38 of the diffuser 30 at a position facing each other through the through hole 37, and the bridge portion 12 is engaged. A pair of positioning ribs 40, 40 that are positioned relative to each other are provided in a protruding manner. Also, the disk portion 38
On the back surface of the inner edge 39b of the notch 39 along the substantially circumferential direction.
A plurality of continuous rectifying walls 41 are provided.

Further, on the outer peripheral surface side of the flow regulating wall 41, at a position corresponding to the inner edge 39b of the cutout portion 39 substantially in the circumferential direction,
An inclined surface 42 that gradually widens as it descends from the notch 39 is provided so as to incline from one surface of the disk portion 38 to the rear surface side in the direction in which the flow regulating wall 41 projects. Further, the flange portion 6 of the body case 3 is provided on the outer peripheral portion of the inclined surface 42.
An outer surface rib 43 having an outer peripheral surface that substantially adheres to the inner peripheral surface of
It is provided so as to project in the same direction as the flow regulating wall 41.

Then, the diffuser 30 has the outer ribs 4
The outer peripheral surface of 3 is fitted to the inner peripheral surface of the flange portion 6 of the body case 3, and is attached and fixed to the bridge portion 12 with the screw 13 in a state in which the opening 5 of the body case 3 is closed.

A flow hole 45 is formed by being surrounded by the outer surface of the straightening wall 41, the inner edge 39a, the edge of the outer rib 43 and the lower end of the inclined surface 42, and forms a through hole 45, which forms a pair of facing straightening walls 41, 41 and the disk portion 38. The air passage 46 is formed, and the circulation hole 45 is formed.
The inflow passage 47 through which the air flows is constituted by the inclined surface 42, the outer peripheral surface of the flow rectifying wall 41, and the flange portion 6 of the body case 4 facing each other.

An example of the case in which the body case 3 as described above is formed by a frame body (not shown) will be specifically described. For example, in FIG.
It is possible to form a substantially U-shaped frame body by notching the body portion except for the portion fixing the two parts, and the remaining one body portion, the bridge portion 12 and the other body portion. The stator 18 and the brush mechanism 22 are fixed to the body portion of the remaining portion of the frame body, and the bridge portion 1 located in the front is also fixed.
A bearing accommodating portion 9 forming a pair with the second bearing portion 15 is provided in the rear plate portion 7. This makes it possible to reduce the weight of the body case 3 and the electric motor 2 as a whole.

The diffuser 30 is provided to rectify the gas sucked by the fan 31 and smoothly flow into the motor body 4 to enhance the air-cooling effect and to effectively suppress the temperature rise of the electric blower 2. However, if it is necessary to reduce the weight and the size of the diffuser 30 even if the performance is slightly deteriorated, the diffuser 30 can be formed in a simple shape or can be eliminated.

On the other hand, as shown in FIG. 1, a circular fan cover 50 is fitted on the outer peripheral portion of the flange portion 6 of the body case 3, and the fan 31 is covered by the fan cover 50. The fan cover 50 has an intake port 51 formed in the center of the front surface, is bent by a curved portion 52, and has a rear opening 53 on the entire rear surface and is formed in a bowl shape as a whole.

The fan 31 will be specifically described with reference to FIGS. 3, 5, and 6. The fan 31 includes a substantially planar disc-shaped rear shroud 54, a disc-shaped front shroud 55 that faces the rear shroud 54 at regular intervals, and has a disc-shaped front shroud 55. It is composed of a plurality of plate-shaped fan blades 56 fixed in contact with each other between these inner surface walls at a right angle.

The rear shroud 54 has the rotary shaft 20 inserted into the mounting hole 32 at the center thereof as described above.
The fan 31 is sandwiched between the two washers 36, 36, and the entire fan 31 is fixed to the rotary shaft 20. On the outer peripheral portion of the rear surface shroud 54, an annular projecting edge 57 having a constant length is formed, the cross section of which is bent substantially at a right angle toward the diffuser 30 side or the rear of the body case 3.

The front shroud 55 is the fan cover 50.
A circular suction port 58 is provided in the central portion facing the suction port 51, and a curved surface 59 is provided so as to project toward the rear shroud 54 side from the suction port 58 toward the outer peripheral direction. Due to the presence of this curved surface 59, the front shroud 55
The distance between the rear shroud 54 and the rear shroud 54 becomes gradually narrower toward the outer periphery as can be seen in FIG. The outer peripheral portion of the front shroud 55 which is continuous with the curved surface 59 is provided with an annular arc-shaped portion 60 whose cross section is curved from the outer peripheral direction toward the outer surface rib 43 of the diffuser 30, and the end portion of the arc-shaped portion 60 is provided. Reference numeral 61 is flush with the end of the annular protruding edge 57 of the rear shroud 54 to form a discharge port 62.

The outer surface of the arc-shaped portion 60 is the fan cover 50.
The curved portions 52 have substantially the same curved shape as that of the curved portion 52 at the outer peripheral end, and are arranged so as to be close to each other. The fan cover 50 is formed by making the end 61 of the arc-shaped portion 60 and the end of the body case 3 extremely close to each other or by extending the end of the body cover 3.
Can be eliminated.

The fan blades 56 have a spiral curved surface 7.
It consists of a number of metal plates and is radially arranged at equal intervals to divide the 360-degree annular space created between the front shroud 55 and the rear shroud 54 into seven parts, and each partitioned space is almost in a secret state. It is fixed to the front shroud 55 and the rear shroud 54 by means such as caulking. The fan blades 56 are not curved spirals,
It is also possible to use a plurality of metal plates that are linearly extended from the suction port in the outer peripheral direction at equal intervals.

The inner peripheral edge 63 of each fan blade 56 is
Located approximately at the inner edge of the intake port 58 of the front shroud 55,
The outer peripheral edge 64 is close to the space formed by the end portion 61 of the arcuate portion 60 of the front shroud and the annular protruding edge 57 of the rear shroud 54. The distance between the adjacent fan blades 56 becomes wider toward the outer peripheral edge, and each outer peripheral edge 64 diagonally traverses the discharge port 62 from the outer peripheral portion of the rear shroud 54 to the arc-shaped portion 60 of the front shroud 55. It is provided so that it touches. The fan blades 56 are arranged at equal intervals, but the number of the fan blades 56 varies depending on the inclination angle of the spiral and is not limited to seven.

Next, the operation of the above embodiment will be described.

The electric blower 1 housed in the main body of the electric vacuum cleaner (not shown) is driven by the operation of the power switch at the time of cleaning to perform the work. The electric blower 1 is driven by electric power supplied to the motor main body 4 through the brush mechanism 22, and the motor main body 4 is rotated by the rotary shaft 20.
The fan 31 attached to is rotated in the direction of arrow A in FIGS.

By the rotation of the fan 31, the fan blades 5
The air flowing in from the intake port 51 of the fan cover 50 by the action of 6 enters from the intake port 58 of the fan 31 and is pushed out in the outer peripheral direction between the front shroud 55 and the rear shroud 54 to flow through the arc-shaped portion 60. After passing through the outlet 62
Is emitted from the diffuser toward the diffuser 30.

At this time, the gas flowing in the fan 31 is redirected by the arcuate portion 60 of the front shroud 55,
The fan blades 56 are always accelerated to reach the discharge port 62. Accelerating the airflow from the fan blades 56 until just before flowing into the diffuser 30 or the body case 3
This is an important factor for downsizing the electric blower 1.

The air discharged from the outlet 62 of the fan 31 flows from the inflow path 47 of the diffuser 30 to the inclined surface 4.
It is converted into a flow toward the second side, and further flows from the circulation hole 45 to the air passage 46 on the back surface side of the diffuser 30. And
The intake air flow is guided by the flow straightening wall 41 forming the air passage 46 and flows spirally toward the center of the diffuser 30, and is the opening 5 of the body case 3 of the electric motor 2 located on the back surface side of the diffuser 30. The air flows into the fuselage case 3 from the ventilation port 16 and flows while cooling the motor main body 4 while passing through the air outlet 1
Exhausted from 1.

When the body case 3 is formed into the above-mentioned lattice-shaped frame body or a frame body having a simpler shape, the intake air flow diffuses around the body case 3, and at that time, the motor is also used. The cooling effect of the main body 4 is not significantly impaired.

As described above, according to the above-described embodiment, the arcuate portion 60 provided on the outer peripheral portion of the front shroud 55 and the outer peripheral end 64 of the fan blade 56 provided internally to the arcuate portion 60,
The suction force is increased without generating turbulent flow until it passes through this, and the suction force is accelerated until just before being discharged from the discharge port 62 of the fan 31 to the diffuser 30 or the body case 3. As a result, the suction work rate of the electric blower 1 can be improved and the size can be reduced.

Although the electric blower 1 for the electric vacuum cleaner has been described in the above embodiment, the same effect can be obtained with any blower such as a blower having a fan.

The motor body 4 for rotating the fan 31 is not limited to the one having the brush mechanism 22 and may have any other structure.

[0042]

According to the present invention, an annular arc-shaped portion is provided on the outer peripheral portion of the front shroud forming a part of the fan, and the outer peripheral end of the fan blade disposed between the front shroud and the rear shroud is By being inscribed in the arc-shaped portion, it is possible to obtain an electric blower that makes the best use of the outer diameter of the fan, and it is possible to reduce the size of the electric blower and improve the suction power.

[0043]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a fan, a diffuser, and a part of an electric motor according to an embodiment of an electric blower of the present invention.

FIG. 2 is a plan view showing a state in which the bridge portion of the electric blower is attached to the body case.

FIG. 3 is an exploded perspective view showing the fan and the diffuser.

FIG. 4 is a back side plan view of the same diffuser.

FIG. 5 is an exploded perspective view of the same fan.

FIG. 6 is a perspective view seen from the rear shroud side which is the back side of the fan.

FIG. 7 is a cross-sectional view in which a part of a conventional electric blower is cut away.

[Explanation of symbols]

1 ... Electric blower 2 ... electric motor 3 ... Body case 4 ... Motor body 11 ... Outlet 12 ... Bridge 20 ... Rotary axis 30 ... Diffuser 31 ... fan 50 ... Fan cover 54 ... Rear shroud 55 ... Front shroud 56 ... Fan wings 58 ... Intake port 60 ... Arc-shaped part 62 ... Discharge port

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3B006 FA02                 3H022 AA02 BA04 BA06 CA15 DA03                       DA20                 3H033 AA02 AA13 BB02 BB06 BB20                       CC01 CC06 DD06 DD12 EE03                       EE19                 3H035 AA03 AA06

Claims (4)

[Claims] 1. An electric blower including a fan fixed to a rotating shaft of an electric motor, wherein the fan has a rear shroud fixed to the rotating shaft and a plurality of fan blades arranged between the rear shroud. The front shroud has a suction port at the center thereof, and an annular arc-shaped portion inscribed with the outer peripheral portions of the fan blades is provided on the outer peripheral portion of the front shroud. A discharge port is formed by the end portion of the rear shroud and the outer peripheral portion of the rear shroud, and the rotation of the fan changes the direction of the air flow sucked from the suction port of the front shroud and guided to the outer peripheral portion by the arcuate portion. An electric blower characterized by allowing the air to be exhausted from the outlet. 2. An electric motor, a fan fixed to an end of a rotating shaft of the electric motor, a fan cover covering the fan and having an intake port in a central part, and a plurality of fan covers arranged on a downstream side of the fan on an outer peripheral part thereof. And a diffuser in which the inlet of the fan is annularly arranged, and the fan comprises a front shroud and a rear shroud having a plurality of fan blades fixed therebetween, and these shrouds have an intake port of the fan cover. Each of the fan blades has an outer peripheral end that is in contact with an outer peripheral portion of a front shroud that has an inlet and an outlet that are respectively close to an inlet of the diffuser and that forms the outlet. An arc-shaped portion that is substantially orthogonal to the arc-shaped portion, and the airflow that is sucked from the suction port of the front shroud and guided in the outer peripheral direction by the rotation of the fan. The electric blower is characterized in that the air is blown from the discharge port and discharged to the rear via the diffuser. 3. An electric blower having a fan fixed to a rotation shaft of a motor body supported by a body case, wherein the fan is provided between a rear shroud fixed to the rotation shaft and the rear shroud. A front shroud having a plurality of fan blades arranged therein, the front shroud having a suction port at the center thereof, and an annular arc-shaped portion inscribed at the outer peripheral portion of the outer peripheral ends of the fan blades, An exhaust port is formed by the end of the arcuate portion and the outer peripheral portion of the rear shroud, and the airflow that is sucked from the suction port of the front shroud and guided in the outer peripheral direction is rotated by the rotation of the fan. An electric blower, characterized in that the motor main body is cooled by changing the direction by a section and discharging it from the discharge port into the body case. 4. A thrust bearing for supporting an axial thrust generated forward by rotation of the fan, at least one of a plurality of bearings supporting the rotating shaft being a thrust bearing. The electric blower according to claim 1.