JPH063197B2 - Electric blower - Google Patents

Description

The present invention relates to an electric blower used in, for example, an electric vacuum cleaner.

[Conventional technology]

In this type of electric blower, as shown in FIG. 5, a fixed guide plate 103 having a return guide 101 and a differential user 102 is provided above the end bracket 100, and an impeller 10 is provided.
4 and the fan casing 105 in this order, and the impeller 6
The air discharged to the outer periphery of the rotary shaft 10 passes through the diff user 102 and the return guide 101 and flows into the electric motor section 107 from the wind window 106 provided on the upper surface of the end bracket 100.
On the rotary plate 109 fixed to 8, the bottom side shroud plate 110
The impeller 104 is fixed to the rotating shaft 108 by sandwiching and fixing it with a fixing tool 111. Rotating shaft 108
The bearing 112 is supported by a bearing fixing protrusion 113 formed on the upper surface of the end bracket 100, and the central cylindrical portion 103a of the fixed guide plate 103 is press-fitted onto the outer periphery of the bearing fixing protrusion 113.

[Problems to be solved by the invention]

In the above-mentioned conventional example, when the impeller 104 rotates, the space 114 between the bottom shroud plate 110 and the fixed guide plate 103 discharges the air in the space 114 to the outer periphery and becomes a negative pressure, and the impeller 104 outer periphery The air discharged to the inside is sent into the inside of the electric motor unit 107 through the diff user 102, the return guide 101, and the wind window 106, and the inside of the electric motor unit 107 becomes a positive pressure. Therefore, the rotary shaft 108
A flow of air is generated from the inside of the electric motor section 107 toward the space 114 between the bottom shroud plate 110 and the fixed guide plate 103 through the bearing 112 that supports the bearing 112, and dust such as dust is generated together with the air. However, there is a problem in that it may enter the inside of the bearing 112 and cause deterioration of the life of the bearing 112 and deterioration of the lubricating oil.

An object of the present invention is to solve the above problem by blocking the air flowing from the inside of the electric motor section through the bearing to the impeller side.

[Means for solving problems]

The above-mentioned object is to fix an end bracket, a bearing supported in a bearing fixing protrusion of the end bracket, a rotary shaft rotatably supported by the bearing, and a pressing body and an impeller support body to the rotary shaft. In an electric blower including an impeller and a casing that covers the impeller, the impeller support includes a bottomed cylindrical portion that fits into the bearing fixing protrusion, and a bottom side shroud of the impeller. This is achieved by fitting the bearing fixing protrusion into the cylindrical portion, which is formed from a flange portion that abuts the back surface.

[Action]

By fitting the bearing fixing protrusion into the cylindrical portion of the impeller support, the creeping distance between the two can be increased. This suppresses the flow of air from within the motor section into the impeller through the bearings.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 3, an electric blower 1 includes a housing 2 and an end bracket 3, a ring-shaped plate 4 is fixed to the outer periphery of the end bracket 3, and a diff user 15 is arranged on the plate 4. To do. The inner circumference of the differential user 15 is press-fitted into the upper end of the outer circumference of the end bracket 3. The impeller 6 is sandwiched between a blade support 12 and a pressing body 11, and a nut 9 is used to rotate the rotary shaft 7
Fixed to. The casing 5 covering the impeller 6 is press-fitted to the outer peripheral end of the plate 4.

The air sucked into the impeller 6 through the suction port 22 of the casing 5 is discharged from the impeller outlet 23, passes through the diff user 15, passes through the wind window 21 provided in the end bracket 3, and cools the inside of the electric motor. After that, the air is discharged from the air holes 24 provided in the housing 2 to the outside.

When the impeller 5 rotates, the bottom shroud plate 5 of the impeller 6
By the back surface of 1, the air near the back surface receives centrifugal force,
Since the space portion 50 between the bottom shroud plate 51 and the end bracket 3 is pushed out to the outer periphery and has a negative pressure, and the inside of the motor 70 into which air is introduced has a positive pressure, the bearing 8 of the rotary shaft 7 is passed through. Air tries to flow from the inside 70 of the electric motor to the space portion 50. As shown in FIG. 2, this air flow is blocked by the bearing fixing protrusion 20 and the impeller support 12 which are formed integrally with the end bracket 3.

The impeller support 12 includes a bottomed cylindrical portion 40 that fits into the bearing fixing protrusion 20, and a flange portion 30 that abuts the back surface of the bottom shell 51. The pressing body 11 has a cylindrical portion 11a that closely fits the outer periphery of the cylindrical portion 40 of the impeller support 12, a flange portion 11b that abuts the surface of the bottom shell plate 51, and a screw portion 7a of the rotary shaft 7. It has a cylindrical bottom 11d having a recess 11c into which the mating nut 9 fits.

Since the impeller 6 clamped and fixed by the impeller support 12 and the pressing body 11 is rotated by the rotating shaft 7, a gap G is provided between the end bracket 3 and the impeller support 12. The gap G is formed on the outer peripheral surface 52 of the bearing fixing protrusion 20.
And the inner peripheral surface 54 of the cylindrical portion 40 of the impeller support 12, the end surface 53 of the bearing fixing protrusion 20, the bottom end surface 55 of the cylindrical portion 40, the end surface 73 of the flange portion 30 of the cylindrical portion 40, and the upper surface of the end bracket 3. Can be miniaturized and can be made sufficiently long. Since the gap G is long, the creeping distance of the seal portion can be sufficiently secured, so that a high sealing effect can be obtained.

As shown in FIG. 3, the electric blower 1 is assembled by fixing the plate 4 to the end bracket 3 and then the diff user 1
5, blade support 12, impeller 6, pressing body 11, nut 9
And the casing 5 in this order. When the assembly of the electric blower 1 is completed, as shown in FIGS. 1 and 2, the bearing fixing portion 20 is inserted inside the impeller 6, that is, the bottom shroud plate 51.
Since the bearing fixing portion 20 in the central hole 74 is inserted, the height of the entire electric blower is reduced by the amount of the insertion.

FIG. 4 shows another embodiment of the present invention, and the same contents as those of the embodiment of FIGS. 1 to 3 are designated by the same reference numerals. In this other embodiment, the end face 53 of the bearing fixing protrusion 20 and the bottom end face 55 of the cylindrical portion 40 are provided with an annular recess 60 on one side and an annular protrusion 60a on the other side so as to achieve a labyrinth effect. ing. In the example of FIG. 4, the bottom end surface 5 of the cylindrical portion 40 is
The annular concave portion 60 is formed on the side of 5 and the annular convex portion 60a is formed on the side of the end surface 53 of the bearing fixing protrusion 20. If the labyrinth effect can be obtained, the annular concave portion 60 and the annular convex portion 6 are formed in any part of the gap formed between the bearing fixing protrusion 20 and the impeller support 12.
You may provide one or more 0a.

According to this embodiment, the following effects can be obtained.

(1) Cylindrical part 40 of impeller support 12 and bearing fixing protrusion 2
By fitting with 0, the creeping distance of the seal portion can be made sufficiently long and a high sealing effect can be obtained. As a result, the generation of air flow through the bearing 8 is suppressed, and dust such as dust can be prevented from entering the bearing 8.

(2) Since the cylindrical portion 40 of the impeller support 12 and the bearing fixing protrusion 20 are arranged coaxially, the dimensional accuracy of the gap G between the cylindrical portion 40 and the bearing fixing protrusion 20 is stable. It is easy to do.

(3) The bearing fixing protrusion 20 is fitted into the central hole 74 of the bottom shell plate 51 of the impeller 6, and the end bracket 3
By bringing the impeller 6 closer to, the axial dimension of the electric blower 1 can be shortened.

〔The invention's effect〕

According to the present invention, the air flowing from the inside of the electric motor section through the bearing to the impeller side can be blocked, so that an electric blower that can prevent dust and the like from entering the bearing can be obtained.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a partially sectional front view, FIG.
The figure is an exploded perspective view. FIG. 4 is an enlarged sectional view of an essential part showing another embodiment of the present invention, and FIG. 5 is a sectional view of an essential part showing a conventional example. DESCRIPTION OF SYMBOLS 1 ... Electric blower, 3 ... End bracket, 5 ... Casing, 6 ... Impeller, 7 ... Rotating shaft, 8 ... Bearing, 11 ... Press body, 12 ... Blade support body, 20 ... Bearing fixing protrusion, 30 ...
Flange part, 4 ... Cylindrical part, 51 ... Bottom shroud.

Claims (3)

[Claims] 1. An end bracket, a bearing supported in a bearing fixing protrusion of the end bracket, a rotary shaft rotatably supported by the bearing, and a pressing body and an impeller support body for the rotary shaft. In an electric blower comprising a fixed impeller and a casing covering the impeller, the impeller support includes a bottomed cylindrical portion fitted to the bearing fixing protrusion, and a bottom side of the impeller. An electric blower, characterized in that it is formed of a flange portion that comes into contact with the back surface of the shell, and that the bearing fixing protrusion is fitted in the cylindrical portion. 2. The pressing body is formed of a cylindrical portion that is closely fitted to the outer periphery of the cylindrical portion, and a flange portion that abuts on the surface of the bottom shroud of the impeller. The electric blower according to item 1. 3. The inner surface of the cylindrical portion and the bearing fixing protrusion 20.
An annular recess is formed on one of the outer surfaces and an annular projection is formed on the other of the outer surfaces of the outer surface, and the annular projection is fitted into the annular recess. Electric blower described.