JP3539559B2 - Motor fan - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to avoiding restraint abnormalities caused by freezing of a fixed part and a rotating part of a motor fan installed in an environment where there is a risk of freezing, such as in a refrigerator.
[0002]
[Prior art]
As an agitation means in an environment where there is a risk of dew condensation and freezing in the past, there should be no nearby wind tunnel where there is no risk of solidification failure between the fixed part and the rotating part due to dew or freezing, at the expense of stirring efficiency. Even in a propeller fan using an electric motor or an axial fan having a venturi case 1 as shown in FIG. 4, the gap between the inner peripheral surface of the wind tunnel portion 1-1 and the outer peripheral edge 2-1 of the blade 2 is increased. Thus, the danger of condensation and freezing was suppressed.
[0003]
However, even with the use of the axial fan for the purpose of improving the stirring capacity in the refrigerator, the gap between the inner peripheral surface of the wind tunnel portion 1-1 and the outer peripheral edge 2-1 of the blade 2 can be increased as described above. In addition to the fact that the agitation capacity is reduced, it is difficult to completely eliminate the possibility of solidification failure between the fixed part and the rotating part due to dew condensation and freezing.
[0004]
[Problems to be solved by the invention]
The conventional configuration as described above still leaves much room for improvement in order to achieve a result that satisfies the conflicting expectations of desired stirring performance and energy saving for improving stirring efficiency.
[0005]
[Means for Solving the Problems]
The motor fan according to the present invention, in particular, a motor fan installed in an environment where there is a risk of freezing, such as in a refrigerator, has an open end portion of the cylindrical inner peripheral surface of the venturi case facing the open end of the blade. The blade is configured to be offset in the axial direction with respect to the venturi case so as to cover only the outer peripheral edge of the side, and preferably, the axial length of the blade covered by the inner peripheral surface of the open end of the venturi case is: At least 15% or less of the entire axial length of the blade, or at least a portion of the outer peripheral edge of the blade facing the opening end of the Venturi case that is covered by the Venturi case is configured to have a radially inclined surface.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0007]
【Example】
FIG. 1 is a sectional view of an example of a motor fan according to the present invention. As is apparent from comparison with the conventional example shown in FIG. 4 described above, in the conventionally known configuration, the blade is formed on the inner peripheral surface of the wind tunnel portion 1-1 of the venturi case 1 through a small gap by considering only the blowing capacity. In the present invention, the inner peripheral surface of the wind tunnel portion 1-1, which is a fixed member, and the rotating member are opposed to each other by the small air gap while leaving the wind tunnel effect. It is intended to avoid dew condensation and freezing between the outer peripheral edge 2-1 of the blade 2 as described above.
[0008]
Although not shown, in order to avoid dew condensation and freezing due to the proximity of the wind tunnel portion of the Venturi case, which is the fixed portion, and the blade, which is the rotating portion, a guide member for the flow of agitated air is provided externally. However, although a propeller fan without a fixed portion has been put into practical use, the stirring ability has been insufficient, and the adoption of the above-mentioned axial fan has led to the use of the above-described axial fan. Has emerged as a new problem.
[0009]
As shown in FIG. 1, the blade 2 is disposed so as to be deviated in the axial direction from the venturi case 1, but in reality, the venturi case 1 is a short wind tunnel that covers only the discharge port side end of the blade 2. The blade 2 rotates so that most of the blade 2 protrudes from the opening end of the wind tunnel, and the inner peripheral surface of the short wind tunnel 1-1 on the discharge port side so as to rectify the flow of the stirring air. It is configured to send air to. This reduces the number of opposing portions between the inner peripheral surface of the wind tunnel portion 1-1 and the outer peripheral edge 2-1 of the blade 2, thereby eliminating the risk of solidification failure between the fixed portion and the rotating portion due to condensation and freezing. And stabilization of the stirring capacity.
[0010]
It is preferable that the blade 2 is covered with the inner peripheral surface of the wind tunnel portion 1-1 over the entire axial direction, although it is preferable in terms of agitation ability, but the possibility of dew condensation and freezing is increased. In the structure of the propeller fan to be installed as a side, there is no concern about dew condensation and freezing, but taking into account that it is not preferable in terms of agitation ability, taking out the effect of the wind tunnel 1-1, as an appropriate configuration to avoid dew condensation and freezing For example, it has been experimentally confirmed that it is preferable to cover 15% or less of the blade 2 with the short wind tunnel portion 1-1 under practical installation conditions in a home refrigerator or the like. In the configuration of the present invention, it has been confirmed that the performance of a propeller fan provided with a guide member for the air flow which is currently in use is significantly increased in a practical range, particularly on a high static side.
[0011]
Further, as described above, since it is assumed that the inner peripheral surface of the short wind tunnel portion 1-1 and the outer peripheral edge 2-1 of the blade 2 are opposed in the radial direction, there is no concern about dew condensation and freezing due to the proximity of the two. As a means for avoiding this, a radially inclined surface 2-2 for enlarging the facing distance may be provided on the outer peripheral edge 2-1 of the blade 2 sunk into the inner peripheral surface of the wind tunnel portion 1-1. preferable.
[0012]
【The invention's effect】
The motor fan according to the present invention, in particular, a motor fan used in an environment where there is a risk of solidification failure between the fixed part and the rotating part due to condensation and freezing, while preventing a decrease in stirring performance, the motor fan and the fixed part due to condensation and freezing. It is possible to suppress the possibility of solidification failure with the rotating part.
[Brief description of the drawings]
FIG. 1 is a sectional view of an example of a motor fan according to the present invention.
FIG. 2 is an explanatory view of a blade according to the present invention.
FIG. 3 is an explanatory view of the blade in the example of FIG. 1;
FIG. 4 is a cross-sectional view of an example of a conventional motor fan.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Venturi case 1-1 Wind tunnel part 2 Blade 2-1 Blade outer peripheral edge 2-2 Slope

Claims (3)

A venturi case including a cylindrical inner peripheral surface and a motor holding portion connected by a plurality of legs extending from the inner peripheral surface toward the center, a rotor hub, and a plurality of blades implanted in the rotor hub; And an impeller rotatably supported so as to face the inner peripheral surface of the venturi case, and an electric motor held by the electric motor holding portion and arranged inside the rotor hub for driving the impeller. And a motor fan installed in an environment where there is a risk of freezing, such as in a refrigerator, especially in a refrigerator, wherein the open end portion of the cylindrical inner peripheral surface of the venturi case is the open end of the blade. The blades are configured to be offset in the axial direction with respect to the venturi case so as to cover only the outer peripheral edge on the discharge port side facing the fan. 2. The motor fan according to claim 1, wherein the axial length of the blade covered by the inner peripheral surface of the opening end of the venturi case is 15% or less of the entire axial length of the blade. 3. 3. The outer peripheral edge of the blade on the discharge port side facing the venturi case opening end, at least a portion covered by the venturi case is provided with a radially inclined surface. 4. Motor fan.

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