JP2018003764A - Blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower which reduces noise, inhibits deterioration of ventilation performance, and achieves energy saving.SOLUTION: A blower 1 comprises: a casing 2 comprising a cylindrical body part 3 and a bell mouth 4; an electric motor 7 fixed to an interior part of the casing 2; and a propeller type impeller 9 attached to a rotary shaft 7a of the electric motor 7. The propeller type impeller 9 is positioned in the bell mouth 4, and an outer diameter of the propeller type impeller 9 is set larger than an inner diameter of the cylindrical body part 3.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a blower used for ventilation and countermeasures against hot air in a factory or a warehouse, product cooling, and the like.

  A blower used for ventilation and countermeasures against heat in factories and warehouses, product cooling, etc. includes a casing made up of a cylindrical body, a bell mouth coupled to the suction side of the body, and an electric motor fixed in the casing. And a propeller type impeller attached to the rotating shaft of the electric motor.

  In the conventional blower, as shown in FIG. 11, the impeller is located in the cylindrical body (body) of the casing, and the outer diameter of the impeller is naturally larger than the inner diameter of the body. small.

  In general, when an axial fan is operated, as shown in FIG. 8, the suction side of the fan has a negative pressure (negative pressure with respect to the atmosphere), and the discharge side has a positive pressure (plus pressure). And by maintaining this pressure difference, the performance as a fan can be fully exhibited. In addition, it is a cylindrical body (body) that plays a role in maintaining the pressure difference, and by keeping the gap between the tip of the impeller and the inner surface of the body as small as possible, the pressure difference is kept larger. It can be done.

  When air is passed through the cylinder at a certain wind speed, the wind speed near the inner surface of the cylinder is slowed by friction with the inner surface of the cylinder, as shown in FIG. 9 (the boundary surface between the fluid and the solid becomes zero in flow velocity). . Further, when the axial fan is operated, as shown in FIG. 10, a wind speed component in the rotational direction is generated separately from the axial flow direction, and turbulence is generated at the end of the impeller.

And the conventional blower has the structure as described above, and the wind speed component in the rotational direction of the impeller and the turbulent flow generated at the end of the impeller are in a direction orthogonal to the axial flow direction. In the part where the wind speed in the axial flow direction is slow (near the inner surface of the cylindrical body), the perpendicular wind speed is not affected by the friction of the body, and this effect is small because the wind speed in the axial direction is slow. It collides with the inner surface of the body part of the body and bounces back toward the center of the cylindrical body part. And this collides with the wind of an axial flow direction, and becomes a factor which disturbs the flow of the wind of the axial flow direction of a fan mainstream. Then, the disturbance of the wind flow in the axial direction of the main flow causes problems such as high noise, pressure fluctuations, large vibrations, and a large load on the motor. Is.

  The present invention has been made in view of the above points, and is a cylindrical shape in which the tip of the impeller is in a position where the wind speed in the axial direction does not slow down, that is, the wind speed slows down due to friction on the inner surface. By installing the impeller in the bell mouth instead of the trunk, wind speed components (components orthogonal to the axial flow direction) such as wind speed components in the rotational direction of the impeller and turbulent flow at the tip of the impeller An object of the present invention is to provide a blower which can be pushed in a direction along the wind flow in the axial direction of the mainstream and can solve the above-mentioned conventional problems.

  Thus, the gist of the present invention is that a casing made of a cylindrical body, a bell mouth coupled to the suction side of the body, a motor fixed in the casing, In a blower comprising a propeller type impeller attached to a rotating shaft, the propeller type impeller is positioned in the bell mouth, and the outer diameter of the propeller type impeller is set to the inner diameter of the cylindrical body. The blower is characterized by being made larger.

  As described above, the present invention is such that the propeller-type impeller is positioned in the bell mouth, and the outer diameter of the propeller-type impeller is made larger than the inner diameter of the cylindrical body, and the tip of the impeller The position where the wind speed in the axial direction does not slow down, that is, not the cylindrical body where the wind speed slows down due to friction on the inner surface, but it is located in the bell mouth and the impeller is attached. It can push the wind speed component in the rotational direction of the car and the wind speed component such as turbulent flow at the tip of the impeller (component orthogonal to the axial flow direction) in the direction along the wind flow in the mainstream axial flow direction. It is. As a result, conventional problems such as increased noise, increased pressure due to fluctuations in pressure, and increased load on the motor due to disturbance of the wind flow in the axial direction of the mainstream. It can be solved ugly.

It is a left view of the air blower concerning the embodiment of the present invention. It is the same rear view. It is the same top view. It is the center longitudinal cross-sectional side view. It is a right view of the casing. It is a rear view of the casing. FIG. It is a schematic explanatory drawing of the conventional air blower. It is explanatory drawing of the wind speed in the conventional air blower. It is explanatory drawing of generation | occurrence | production of the wind speed component to the rotation direction in the conventional air blower. It is explanatory drawing of the structure and effect | action of the conventional air blower.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  In the figure, 1 is a blower. The blower 1 is composed of a casing, a motor, and a propeller impeller described later.

Reference numeral 2 denotes a casing of the blower 1 including a cylindrical body 3 and a bell mouth 4 coupled to the suction side of the body 3. Further, a lifting ring 2A is provided on the outer surface of the top of the cylindrical body 3 in the casing 2, and a net-like safety guard 2B is attached to the suction side and discharge side openings of the casing 2.

Reference numeral 5 denotes a support frame that supports the casing 2 so that the angle of elevation can be adjusted. Reference numerals 5A and 5B denote connecting members between the support frame 5 and the casing 2.

  Reference numeral 7 denotes an electric motor that is fixed inside the cylindrical body 3 of the casing 2. Reference numeral 8 denotes a stay that supports and fixes the electric motor 7 inside the cylindrical body 3.

  Reference numeral 9 denotes a propeller-type impeller attached to the rotating shaft 7a of the electric motor 7. In this embodiment, the propeller type impeller 9 is made of metal, but may be made of other materials.

  The above configuration is the same as that of a conventional blower. Thus, the present embodiment is characterized in that the propeller impeller 9 is positioned in the bell mouth 4 and the outer diameter L1 of the propeller impeller 9 is set to the cylindrical barrel. This is because it is larger than the inner diameter L of the portion 3.

Next, the operation of this embodiment will be described.
As described above, the propeller-type impeller 9 is positioned in the bell mouth 4 and the outer diameter of the propeller-type impeller 9 is made larger than the inner diameter of the cylindrical body 3 so that the tip of the impeller 9 is Since the wind speed in the axial direction does not slow down, that is, not the cylindrical body 3 where the wind speed slows down due to friction on the inner surface, but the impeller 9 is mounted in the bell mouth 4 so as to be attached. As shown in FIG. 7, wind velocity components (components orthogonal to the axial flow direction) such as wind velocity components in the rotational direction of the impeller 9 and turbulent flow at the tip of the impeller 9 are converted into wind flow in the mainstream axial flow direction. It can be pushed in the direction along. As a result, conventional problems such as increased noise, increased pressure due to fluctuations in pressure, and increased load on the motor due to disturbance of the wind flow in the axial direction of the mainstream. It can be solved ugly.

DESCRIPTION OF SYMBOLS 1 Blower 2 Casing 3 Cylindrical trunk | drum 4 Bellmouth 5 Support frame 6 Caster 7 Electric motor 8 Stay 9 Propeller type impeller

Claims (1)

A blower comprising a casing made of a cylindrical body, a bell mouth coupled to the suction side of the body, an electric motor fixed in the casing, and a propeller impeller attached to the rotating shaft of the electric motor The blower is characterized in that the propeller impeller is positioned in the bell mouth, and the outer diameter of the propeller impeller is made larger than the inner diameter of the cylindrical body.

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