JPH05231390A - Electric motor-driven blower - Google Patents

Abstract

PURPOSE:To enlarge a sectional area of a return flow path so as to improve suction performance by fixing a bearing holding part, having a plurality of ribs, to a load side bracket holding a bearing press-fitted to a shaft of an armature, and further tilting each rib respectively in a plurality of specific directions. CONSTITUTION:A load side bracket 10a for holding a bearing 4 is press-fitted to one end in a shaft 3 of an armature 1 having a commutator 2. An impeller 7 is fixed to the shaft 3 to coat upward of this impeller with a casing 8 and also to correspond by each port 7a, 8a of these impeller and casing. Further by the load side bracket 10a and an air guide 6, a return flow path 16 is partitioned. In the above constitution, a bearing holding part 11 is fixed by machine screws 12 to the load side bracket 10a, to constitute this part 11 of a plurality of ribs 3, fixed part 14 and a housing 15 of mounting the bearing 14. Each rib 13 is tilted in an opposite load side from the center of the shaft 3 toward the periphery and also tilted in also the circumferential direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blower used for a vacuum cleaner or the like.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for improving the efficiency of electric blowers in order to improve the suction performance of electric vacuum cleaners.

Conventionally, this type of electric blower has a structure as shown in FIG. The configuration will be described below with reference to the drawings. As shown in the figure, the armature 1 has a commutator 2, and bearings 4 are press-fitted at both ends of a shaft 3. The bearings 4 are supported by a bracket 5 made of a resin material and an air guide 6, and the bracket 5 Is composed of a load side bracket 5a and an anti-load side bracket 5b. The load side bracket 5a and the air guide 6 allow the inlet passage 6a,
The return channel 6b is formed. Shaft 3 on the load side of armature 1
Penetrates the air guide 6, and an impeller 7 is fixed to the shaft 3 of the air guide 6. The impeller 7 has an intake port 7a, and the upper part thereof is covered with a casing 8 having an intake port 8a.
Then, when the impeller 7 rotates, air is taken in through the intake port 8a of the casing 8 from the intake port 7a of the impeller 7, and is exhausted through the air guide 6.

[0004]

However, in the above-mentioned conventional structure, it has been attempted to increase the cross-sectional area of the return passage 6b of the air guide 6 in order to improve the suction performance. There was a problem that there was a limit in expanding.

The present invention solves the above-mentioned conventional problems, and an object thereof is to provide an electric blower capable of improving the suction performance.

[0006]

In order to achieve the above-mentioned object, the present invention fixes a bearing holding portion having a plurality of ribs to a load side bracket, and the ribs are opposite to the load side from the shaft center toward the outer periphery. The cross-sectional area of the return flow channel is enlarged along the exhaust direction by inclining to a substantially circumferential direction.

[0007]

In the above structure, when the impeller rotates, air is drawn from the intake port of the impeller through the intake port of the casing and exhausted through the return passage, but the cross-sectional area of the return passage expands along the exhaust direction. Therefore, the dynamic pressure component of the exhausted air becomes a static pressure component and is smoothly discharged.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this example,
The same components as those shown in the above-mentioned conventional example are designated by the same reference numerals, and the description thereof will be omitted. The characteristic configuration of this embodiment is that the air outflow portion of the load side bracket described in the conventional example is enlarged in cross section along the discharge direction. That is, the bracket 10 is composed of a load side bracket 10a and an anti-load side bracket 10b, and a bearing holding portion 11 is fixed to the load side bracket 10a with screws 12. Figure 2
As shown in (a), the bearing holder 11 has a plurality of ribs 13
And a housing 15 in which the bearing 4 is mounted. As shown in FIG. 3, the ribs 13 are inclined from the center of the shaft 3 toward the outer periphery toward the anti-load side, and as shown in FIG. 2B, the ribs 13 are also inclined substantially in the circumferential direction. (A <B). Therefore, the cross-sectional area of the return passage 16 formed by the rib 13 and the air guide 6 is enlarged along the exhaust direction.

Next, the operation will be described. When the impeller 7 rotates, air is sucked from the intake port 7a of the impeller 7 through the intake port 8a of the casing 8 and exhausted through the return flow passage 16.

As described above, according to the electric blower of the embodiment,
Since the cross-sectional area of the return flow passage 16 is enlarged along the exhaust direction, the dynamic pressure component of the exhausted air is converted into a static pressure component and is smoothly discharged.

[0011]

As is apparent from the above-described embodiments, in the electric blower of the present invention, the load side bracket has the bearing holding portion having a plurality of ribs fixed, and the ribs are on the opposite side from the shaft center toward the outer periphery. The cross-sectional area of the return flow channel is enlarged along the exhaust direction by inclining to approximately the circumferential direction and by increasing the dynamic pressure component of the air exhausted from the impeller by this configuration. It can be effectively converted into a static pressure component and the suction performance can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an electric blower according to an embodiment of the present invention.

FIG. 2 (a) is a plan view of a load side bracket of the electric blower. FIG. 2 (b) is a side view of the load side bracket taken along the line AA.

[Figure 3] Side view of the same load side bracket

FIG. 4 is a side sectional view of a conventional electric blower.

[Explanation of symbols]

 1 Armature 2 Commutator 3 Shaft 4 Bearing 6 Air guide 7 Impeller 7a Intake port 8a Casing 8a Intake port 10a Load side bracket 11 Bearing holding part 13 Rib 16 Return flow path

Claims (1)

[Claims] 1. An armature having a commutator, a load side bracket that holds a bearing press-fitted to one end of a shaft of the armature, an air guide fixed to the load side bracket, and the armature. Impeller having an intake port fixed to the shaft of the shaft, a casing having an intake port provided above the impeller and corresponding to the impeller intake port, a return flow formed by the load side bracket and the air guide. A bearing holding portion having a plurality of ribs is fixed to the load side bracket, and the ribs are inclined toward the opposite load side from the center of the shaft toward the outer periphery and are inclined with respect to the substantially circumferential direction. An electric blower in which the cross-sectional area of the return passage is enlarged along the exhaust direction.