JPH03233194A - Electric fan - Google Patents

Abstract

PURPOSE:To enhance air blowing efficiency by providing a cylindrical reflux shielding member in a suction port of a casing, and shielding the reflux between a front shroud of an impeller and the casing. CONSTITUTION:An air guide 20 is disposed around an impeller 18. A casing 21 covers the impeller 18 and the air guide 20. A member fixing groove is formed in the vicinity of a suction port 22 of the casing 12. A cylindrical reflux shielding member 25 is bonded with an adhesive or the like inside the member fixing groove, and pressed against a front shroud 14 so that the reflux between the front shroud 14 of the impeller 18 and the casing 12 can be shielded substantially completely. Therefore, efficiency of a fan can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric blower for generating suction pressure used in a vacuum cleaner or the like.

BACKGROUND ART A conventional electric blower of this type will be explained with reference to FIG. In the figure, 1 is a motor, 2 is its rotating shaft, 3 is an impeller fixed to the rotating shaft 2, 4 is an air guide located on the outer periphery of the impeller 3, 5 is a casing that covers the impeller 3 and the air guide 4, and the motor It is press-fitted into the bracket 6 and fixed. Reference numeral 7 designates a suction port through which airflow is sucked, 8 a bearing on the impeller side, and 9 a bearing holding portion on the opposite side thereof. The casing 5 is configured to be positioned with an appropriate gap from the front shroud 1o of the impeller 3 so as not to come into contact with the impeller 3.

With the above configuration, the impeller 3 fixed to the rotating shaft 2 rotates at high speed to generate airflow and suction pressure.

Problems to be Solved by the Invention The electric blower having the conventional configuration described above had the following problems. That is, the cause of this problem exists in the gap 11 between the casing 5 and the front shroud 10. The static pressure distribution is lowest near the suction lower, and higher near the discharge port 12 of the impeller 3. From this, a part of the airflow discharged from the discharge port 12 of the impeller 3 is drawn toward the suction lower through the gap 11, and a reflux that circulates between the inside of the impeller 3 and the gap 11 occurs. As a countermeasure against this, a folded portion 13 toward the impeller 3 side is provided on the suction lower portion of the casing 5. However, this was not sufficient to prevent the above-mentioned reflux, and reflux remained. In other words, impeller 3 is also working to generate this return flow, but since this work does not affect the outside, it is one of the causes of lowering the air blowing efficiency of the electric blower as a whole. In addition, since the folded part 13 narrows the suction port of the impeller, there is something that obstructs the airflow on the path from the outside to the inside of the impeller, which also improves efficiency. This was a contributing factor to the decline.

Therefore, the present invention is intended to solve the above-mentioned conventional problems, and its first objective is to obtain an electric blower with high air blowing efficiency by eliminating recirculation. In addition to the first objective, a second objective is to provide an electric blower with high air blowing efficiency by smoothly introducing airflow from the outside. Furthermore, a third object of the present invention is to provide an electric blower with high air blowing efficiency by further ensuring the flow of air into the impeller with a simple configuration.

Means for Solving the Problems A first means for achieving the first objective includes an impeller, an air guide installed around the impeller, and a casing that covers the impeller and the air guide, the casing comprising: A reflux blocking member with good sliding properties is provided at the suction port, and the reflux blocking member has a cylindrical shape and is in substantially contact with the front shroud of the impeller.

A second means for achieving the second object is to provide an electric blower in which the casing is provided with a cylindrical guide oriented in the direction of inflow of airflow.

A third means for achieving the third object includes an impeller, an air guide installed around the impeller, and a casing that covers the impeller and the air guide, and an inlet guide tube at the suction port of the casing. The inlet guide cylinder forms a cylindrical guide in the direction of the airflow, and serves as a reflux blocking member with good sliding properties in the direction of the impeller, and the inner diameter through which the airflow passes is the impeller. The electric blower has a diameter that approximately matches the diameter of the suction port.

In the electric blower according to the first means of operation, the return flow into the gap between the casing and the front shroud is blocked by the action of the return flow blocking member, and the return flow blocking effect is almost perfect. Therefore, the air blowing efficiency can be improved. In addition to the effect of the first means, the electric blower according to the second means can smoothly suck in airflow from the outside as a cage having a cylindrical guide, and can improve the layer blowing efficiency. It is something. Furthermore, according to the third means, the effects of the first means and the second means can be realized with a simpler configuration.

EXAMPLES Hereinafter, examples of the first means of the present invention will be explained with reference to FIGS. 1 to 4. In Figures 1 and 2, 14
is the front shroud, 15 is the rear shroud, and 16
- 17 is a blade, and each of these members is integrated to constitute an impeller 18. An air guide 20 is disposed around the impeller 18 and has the function of converting the dynamic pressure of the discharge flow from the impeller 18 into static pressure and the function of guiding airflow into the motor 19 to cool the motor 19. There is. In addition, these impellers 18 and air guides 20
A casing 21 is provided to cover the. 22 is a suction port of the casing 21, and 23 is a suction port of the impeller 18. In this embodiment, a member fixing groove 24 is provided near the suction port 22 of the casing 21. Further, a cylindrical reflux blocking member 25 is fixed in the member fixing groove 24 with an adhesive or the like, and is pressed against the front shroud 14 . In addition, the inner diameter of the reflux blocking member 25 and the inner diameter of the suction port 23 of the impeller 18 are approximately equal and flush with each other, and the airflow sucked in from the suction port 22 of the casing 21 follows a substantially straight path to the suction port 23 of the impeller. It reaches the mouth 23. As shown in FIGS. 3 and 4, this reflux blocking member 25 is attached to the casing 21 and the front shroud 1 during assembly.
The pressure contact portion 29 with the front shroud 14 is pressed against the front shroud 14 due to the rotation of the impeller 18 during the first operation after assembly.
is scraped off so that the contact portion 30 is in a substantially contact state. Therefore, after the first operation, it rotates while maintaining an airtight state with the front shroud 14, but almost in contact with the front shroud 14.

Next, the operation of the configuration of this embodiment will be explained. As the impeller 18 rotates, the pressure near the suction port 22 decreases. As this pressure decreases, the airflow is drawn toward the suction port 22. In this case, the suction port 22
A gap 26 between the front shroud 14 of the impeller 18 and the casing 21 can be considered as a passage to the flow, but in this embodiment, a reflux blocking member 25 is present in this passage.

This reflux blocking member 25 is attached to the front shroud 1 during assembly.
4, and this pressure contact portion is scraped off by the initial rotation of the impeller 18. Therefore, the gap remaining between the impeller 18 and the impeller 18 is extremely small and can be said to be in a state of close contact. Therefore, the ability to block airflow is very high, and therefore the gap 26 cannot function as a passage. In addition to this, since the inner diameter of the reflux blocking member 25 is approximately equal to and flush with the inner diameter of the suction port 23 of the impeller 18, the airflow flows relatively smoothly from the outside to the inside of the impeller 18. It will flow.

As a result, the impeller 18 no longer needs to work to generate reflux that does not perform any work on the outside, and can work on the outside that much, and the airflow can flow smoothly into the impeller 18. In combination, the efficiency of the blower can be increased.

Next, an embodiment of the second means having a cylindrical guide will be described with reference to FIG. 27 is a cylindrical guide provided integrally with the casing 21 toward the inflow direction of the airflow;
The reflux blocking member 25 forms a rectifying passage up to the impeller 18.

The airflow can flow into the impeller 18 more smoothly due to the cylindrical guide 27 than in the first embodiment described above, resulting in a more efficient electric blower.

Next, an embodiment of the third means will be explained based on FIG. 6. In this embodiment, the suction port 23 of the impeller 18
An inlet guide tube 28 is provided that reaches up to the point. This inlet guide tube 28 has the function of the reflux blocking member 25 of the first means and the function of the cylindrical guide 27 in the embodiment of the second means.
It has a structure and shape that fulfills two functions at the same time. A cylindrical guide 27 is formed toward the inflow direction of the airflow, and a reflux blocking member 25 with good sliding properties is formed toward the direction of the impeller 18, and the inner diameter through which the airflow passes is the suction port of the impeller 18. The diameter is approximately the same as that of 23.
The airflow from the outside can reach the suction port 23 of the impeller 18 extremely smoothly, and of course, the reflux blocking effect is high, so no unnecessary reflux occurs.

Therefore, a highly efficient electric blower is
This can be realized with a simpler configuration than the embodiment of the second means.

Effects of the Invention As mentioned above, in the electric blower of the first means, since a cylindrical reflux blocking member is provided at the suction port of the casing, the reflux between the front shroud of the impeller and the casing is almost completely prevented. Therefore, it is possible to provide a highly efficient electric blower that can be shut off. According to the second means, in addition to the configuration of the first means, a cylindrical guide is provided, so that the external airflow can be guided even more smoothly into the invera. It is something that can be provided. Furthermore, according to the third means, the effects of the first and second means can be realized with an even simpler configuration by providing an inlet guide tube that has the function of a reflux blocking member and a cylindrical guide. It is possible.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the first means of the present invention, Fig. 2 is an enlarged sectional view showing the casing and impeller surrounding area partially cut away, and Fig. 3 is an enlarged sectional view of the reflux blocking member. Fig. 4 is an enlarged sectional view partially cut away showing the assembled state, Figure 4 is an enlarged sectional view partially cut away showing the first rotation after assembly, and Figure 5 is the FIG. 6 is an enlarged sectional view of a main part of an electric blower according to an embodiment of the means, FIG. 6 is an enlarged sectional view of a main part of an electric blower according to a third means, and FIG. 7 is a sectional view of a main part of a conventional electric blower. 14... Front shroud, 18... Impeller, 19
...Motor, 20...Air guide, 21...Casing, 25...Recirculation blocking member, 27...Cylindrical guide, 28...Inlet guide tube.

Claims (3)

[Claims] (1) An impeller, an air guide installed around the impeller, and a casing covering the impeller and the air guide, the casing having a reflux blocking member with good sliding properties at its suction port, and the reflux blocking member is an electric blower that is cylindrical and almost in contact with the front shroud of the impeller. (2) The electric blower according to claim 1, wherein the casing is provided with a cylindrical guide directed toward the inflow direction of the airflow. (3) comprising an impeller, an air guide installed around the impeller, and a casing that covers the impeller and the air guide, and an inlet guide cylinder provided at the suction port of the casing;
This inlet guide tube constitutes a cylindrical guide in the direction of airflow inflow, and serves as a reflux blocking member with good sliding properties in the direction of the impeller, and the inner diameter through which the airflow passes is the suction port of the impeller. An electric blower with a diameter that roughly matches the diameter of the