ventilation fan

Abstract

To acquire a ventilation fan which can use the same component while being capable of changing presence / absence of exposure of an electric motor and an electric motor fixing member according to the use of the ventilation fan and which has good air blowing efficiency.SOLUTION: A ventilation fan 100 includes: a body frame 1 having a bell mouth 11; an electric motor 2; an impeller 3; an electric motor fixing member 4 for connecting the body frame 1 and the electric motor 2; and a mounting part 5 which is provided at the body frame 1, and on which the electric motor fixing member 4 is mounted. The body frame 1 includes a surface 12a and a rear surface 12b. The mounting part 5 includes a first mounting part 51 and a second mounting part 52. The ventilation fan is constituted so as to select between a first use ventilation fan 110 in which the electric motor fixing member 4 is mounted on the first mounting part 51 and a second use ventilation fan in which the electric motor fixing member 4 is mounted on the second mounting part 52. The mounting part 5 is constituted in such a manner that, in both first use ventilation fan 110 and second use ventilation fan, a rear edge end 37 of the impeller 3 is stored in a minimum inside diameter part 11a of the bell mouth 11.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a ventilation fan that generates airflow by rotating an impeller. [Background technology]

[0002] The main uses of ventilation fans include ventilation applications where they are used to ventilate large spaces in buildings such as factories and warehouses, and applications where they are incorporated into equipment such as chillers and air conditioners and used as air-blowing or cooling fans.As disclosed in Patent Document 1, ventilation fans generally include parts such as a main body frame with a cylindrical bell mouth with a variable inner diameter, an electric motor arranged apart from the bell mouth in the axial direction of the bell mouth, an impeller attached to the electric motor that rotates with the rotation of the motor to generate airflow, and an electric motor fixing member that connects the main body frame to the electric motor.

[0003] In ventilation applications, the motor and motor fixing member are generally exposed on the design side of the ventilation fan, but in device-integrated applications, a structure in which the motor and motor fixing member are not exposed on the design side of the ventilation fan is required to improve the appearance of the device.In other words, it is desirable to be able to change whether the motor and motor fixing member are exposed or not depending on the application of the ventilation fan. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-218714 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the ventilation fan disclosed in Patent Document 1, the motor and motor fixing member are arranged inside the main body frame and are not always exposed on the design side of the ventilation fan, which creates the problem that it is not possible to change whether the motor and motor fixing member are exposed or not depending on the use of the ventilation fan.

[0006] Because the structure of a ventilation fan differs depending on whether the motor and motor mounting member are exposed or not, it may not be possible to standardize parts. For this reason, there is a need to develop a ventilation fan that allows the use of the same parts even when the motor and motor mounting member are exposed or not depending on the application of the ventilation fan.

[0007] It is known that ventilation fans with impellers can be obtained with high airflow efficiency by fitting the trailing edge of the impeller into the smallest inner diameter portion of the bellmouth. Therefore, there is a need for the development of a ventilation fan that allows the trailing edge of the impeller to fit into the smallest inner diameter portion of the bellmouth even when the exposed or non-exposed state of the motor and motor fixing member is changed depending on the application of the ventilation fan.

[0008] The present disclosure has been made in consideration of the above, and aims to provide a ventilation fan that can change whether or not the motor and motor fixing member are exposed depending on the use of the ventilation fan, while using the same parts, and that has good air flow efficiency. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the ventilation fan according to the present disclosure has a cylindrical bell mouth whose inner diameter changes. a fixed portion extending radially outward from the outer peripheral surface of the bell mouth; a main body frame having the above-mentioned structure, an electric motor arranged apart from the bell mouth in the axial direction of the bell mouth, an impeller attached to the electric motor and rotating with the rotation of the electric motor to generate an air flow, an electric motor fixing member connecting the main body frame and the electric motor, and the main body frame Fixed part of and a mounting portion provided on the main body frame to which the motor fixing member is attached. The main body frame has a front surface facing one axial direction and a back surface facing the other axial direction. The mounting portion includes a first mounting portion provided on the front surface and a second mounting portion provided on the back surface. The ventilation fan is configured to be selectable between a first-purpose ventilation fan in which the motor fixing member is attached to the first mounting portion and a second-purpose ventilation fan in which the motor fixing member is attached to the second mounting portion. The mounting portion is configured so that the rear edge of the impeller fits into the smallest inner diameter portion of the bell mouth in both the first-purpose ventilation fan and the second-purpose ventilation fan. [Effects of the Invention]

[0010] The ventilation fan according to the present disclosure has the advantage that the motor and motor fixing member can be exposed or not depending on the application of the ventilation fan, the same parts can be used, and a ventilation fan with good air blowing efficiency can be obtained. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing the appearance of a ventilation fan suitable for ventilation purposes according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing the appearance of a ventilation fan suitable for use in incorporating equipment according to a first embodiment; [Figure 3] 3 is a cross-sectional view of the ventilation fan suitable for ventilation purposes according to the first embodiment taken along line III-III shown in FIG. 1. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view of the bell mouth and its surroundings shown in FIG. 3 of the ventilation fan suitable for ventilation purposes according to the first embodiment. [Figure 5] 3 is a cross-sectional view of the ventilation fan suitable for device integration according to the first embodiment, taken along line VV in FIG. 2. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view of the bell mouth and its surroundings shown in FIG. 5 of the ventilation fan suitable for built-in use in the first embodiment. [Figure 7] FIG. 10 is a perspective view showing the appearance of a ventilation fan suitable for ventilation purposes according to a second embodiment. [Figure 8] FIG. 10 is a view showing an impeller of a ventilation fan suitable for ventilation purposes according to a second embodiment, as viewed from the negative pressure side of the impeller. [Figure 9] 9 is a projection view showing an impeller of a ventilation fan suitable for ventilation purposes according to a second embodiment, in which the impeller shown in FIG. 8 is viewed from a direction perpendicular to the axial direction. [Figure 10] FIG. 10 is a projection view showing another impeller of the ventilation fan suitable for ventilation purposes according to the second embodiment, as viewed from a direction perpendicular to the axial direction. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a ventilation fan according to an embodiment will be described in detail with reference to the drawings.

[0013] Embodiment 1 FIG. 1 is a perspective view showing the appearance of a ventilation fan suitable for ventilation purposes according to a first embodiment. FIG. 2 is a perspective view showing the appearance of a ventilation fan suitable for built-in use according to the first embodiment. FIG. 3 is a cross-sectional view of the ventilation fan suitable for ventilation purposes according to the first embodiment, taken along line III-III shown in FIG. 1. FIG. 4 is a cross-sectional view of the ventilation fan suitable for ventilation purposes according to the first embodiment, enlarging a portion around the bell mouth shown in FIG. 3. FIG. 5 is a cross-sectional view of the ventilation fan suitable for built-in use according to the first embodiment, taken along line VV shown in FIG. 2. FIG. 6 is a cross-sectional view of the ventilation fan suitable for built-in use according to the first embodiment, enlarging a portion around the bell mouth shown in FIG. 5. In the following description, the ventilation fan suitable for ventilation purposes will be referred to as a first-purpose ventilation fan 110, and the ventilation fan suitable for built-in use will be referred to as a second-purpose ventilation fan 120.

[0014] As shown in FIGS. 1 and 2, the first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 are configured using common components. The first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 each include a main body frame 1, a motor 2, an impeller 3, a motor fixing member 4, and a mounting portion 5. The structural difference between the first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 is whether the motor fixing member 4 is fixed to the front surface 12a, which serves as the design surface of the main body frame 1, thereby exposing the motor 2 and motor fixing member 4, as shown in FIG. 1, or whether the motor fixing member 4 is fixed to the back surface 12b, which serves as the product fixing surface of the main body frame 1, thereby concealing the motor 2 and motor fixing member 4, as shown in FIG. 2. The structural differences between the first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 will be explained in detail after explaining the common components.

[0015] In the following description, the first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 may be collectively referred to as ventilation fan 100 without distinction. Arrow X1 shown in Fig. 1 indicates the airflow direction of the first-purpose ventilation fan 110. Arrow Y1 shown in Fig. 1 indicates the rotation direction of a motor 2 (described later) in the first-purpose ventilation fan 110. Arrow X2 shown in Fig. 2 indicates the airflow direction of the second-purpose ventilation fan 120. Arrow Y2 shown in Fig. 2 indicates the rotation direction of a motor 2 (described later) in the second-purpose ventilation fan 120. The airflow direction X1 and the airflow direction X2 are opposite to each other.

[0016] The main body frame 1 is a component that is fixed to a building wall (not shown) in the case of the first-purpose ventilation fan 110, and is fixed to equipment such as a chiller or air conditioner in the case of the second-purpose ventilation fan 120. The main body frame 1 has a bell mouth 11, which is an air tunnel, and a fixing portion 12. The bell mouth 11 is formed in a cylindrical shape with a central axis C. When describing the directions of each component of the ventilation fan 100 below, the direction parallel to the central axis C will be referred to as the axial direction, the direction perpendicular to the central axis C and radially outward from the central axis C will be referred to as the radial direction, and the rotational direction around the central axis C will be referred to as the circumferential direction.

[0017] As shown in FIG. 3, the bell mouth 11 has a cylindrical shape with a varying inner diameter. The bell mouth 11 has a minimum inner diameter portion 11a, which has the smallest inner diameter. The minimum inner diameter portion 11a is located in the axial center of the bell mouth 11. The bell mouth 11 is formed in a cylindrical shape with an inner diameter that increases from the minimum inner diameter portion 11a toward both axial ends. Hereinafter, as shown in FIG. 4, the axial length of the minimum inner diameter portion 11a of the bell mouth 11 will be referred to as the range L of the minimum inner diameter portion 11a. Furthermore, one axial end of the minimum inner diameter portion 11a will be referred to as one end 11b, and the other axial end of the minimum inner diameter portion 11a will be referred to as the other end 11c. Furthermore, both axial ends of the minimum inner diameter portion 11a will be referred to as both ends 11b, 11c.

[0018] As shown in Figures 1 and 2, the fixing portion 12 is a plate-shaped portion for fixing the ventilation fan 100 to a building or equipment. The fixing portion 12 is fixed to the building or equipment with fasteners such as bolts. The fixing portion 12 extends radially from one axial end of the outer peripheral surface of the bell mouth 11. The outer peripheral shape of the fixing portion 12 when viewed along the axial direction is not particularly limited, but in this embodiment it is rectangular. The fixing portion 12 of the main body frame 1 has a front surface 12a facing one axial direction and a back surface 12b facing the other axial direction. The front surface 12a is the design surface of the main body frame 1. The back surface 12b is the surface facing the opposite side to the front surface 12a and serves as the product fixing surface that is fixed to the building or equipment. The bell mouth 11 is located on the front surface 12a side of the fixing portion 12.

[0019] In the case of the first-purpose ventilation fan 110 shown in FIG. 1, the back surface 12b of the main body frame 1 is fixed to a wall surface of a building or the like. The first-purpose ventilation fan 110 draws in air from inside the room and blows it out to the outside. In the case of the second-purpose ventilation fan 120 shown in FIG. 2, the back surface 12b of the main body frame 1 is fixed to the outer surface of the equipment to be cooled. The second-purpose ventilation fan 120 draws in air from inside the equipment and blows it out to the outside of the equipment, thereby dissipating heat from inside the equipment.

[0020] As shown in Figures 1 and 2, the motor fixing member 4 is a member that connects the main body frame 1 and the electric motor 2. The motor fixing member 4 has a motor fixing frame 41 and a plurality of motor fixing legs 42. The motor fixing frame 41 is arranged away from the bell mouth 11 along the axial direction. The motor fixing frame 41 is arranged coaxially with the central axis C of the bell mouth 11. The motor fixing frame 41 serves to hold the electric motor 2. The shape of the motor fixing frame 41 is not particularly limited as long as it can hold the electric motor 2, but in this embodiment it is a rectangular frame. An annular flange portion 43 extending radially inward is formed on the inner circumferential surface of the motor fixing frame 41. The electric motor 2 is arranged in the portion of the motor fixing frame 41 surrounded by the flange portion 43.

[0021] The motor fixing legs 42 extend from the motor fixing frame 41 towards the main body frame 1 and support the motor fixing frame 41. The motor fixing frame 41 is connected to the main body frame 1 via multiple motor fixing legs 42. There are no particular restrictions on the number and arrangement of the motor fixing legs 42 as long as the motor fixing frame 41 can be connected to the main body frame 1. In this embodiment, four motor fixing legs 42 are arranged to connect the main body frame 1 and the motor fixing frame 41. The base end of each motor fixing leg 42 is fixed to the mounting portion 5 by a fixing device B such as a bolt.

[0022] The electric motor 2 is a component arranged at a distance from the bell mouth 11 in the axial direction of the bell mouth 11. The electric motor 2 is rotatable. A part of the electric motor 2 is arranged inside the electric motor fixing frame 41 and fixed to the electric motor fixing frame 41. As shown in FIGS. 3 and 5 , the remaining part of the electric motor 2, including the shaft 21, protrudes from the electric motor fixing frame 41 towards the bell mouth 11.

[0023] The impeller 3 is a component that is attached to the electric motor 2 and rotates with the rotation of the electric motor 2 to generate an airflow. A portion of the impeller 3 is disposed inside the bell mouth 11. The impeller 3 has a pressure surface 31 that faces downstream in the airflow directions X1 and X2, and a suction surface 32 that faces upstream in the airflow directions X1 and X2. The pressure surface 31 is the surface of the impeller 3 from which the airflow flows out when the impeller 3 is rotated. The suction surface 32 is the surface of the impeller 3 from which the airflow flows in when the impeller 3 is rotated. The suction surface 32 is the surface that faces the opposite side to the pressure surface 31. The impeller 3 has a boss portion 39 that is fixed to the shaft 21 of the electric motor 2. The boss portion 39 is a cylindrical portion.

[0024] The impeller 3 has a leading edge 33, a trailing edge 34, an outer edge 35, an inner edge 36, and a trailing end 37. The radially outermost ends of the leading edge 33 and the trailing edge 34 are referred to as the "outer end" and the radially innermost ends are referred to as the "inner end." The leading edge 33 is an edge that is located on the front side in the rotation directions Y1 and Y2 when the impeller 3 rotates. The leading edge 33 extends in the radial direction. The trailing edge 34 is an edge that is located on the rear side in the rotation directions Y1 and Y2 when the impeller 3 rotates. The trailing edge 34 extends in the radial direction. The outer edge 35 is an edge that connects the outer end of the leading edge 33 and the outer end of the trailing edge 34. The outer edge 35 extends rearward in the rotation directions Y1 and Y2 from the outer end of the leading edge 33 toward the outer end of the trailing edge 34. The inner edge 36 is an edge that connects the inner end of the leading edge 33 and the inner end of the trailing edge 34. The inner edge 36 extends rearward in the rotational directions Y1 and Y2 from the inner end of the leading edge 33 toward the inner end of the trailing edge 34. The trailing edge 37 is the portion where the trailing edge 34 and the outer edge 35 intersect.

[0025] As shown in FIGS. 1 and 2 , the mounting portion 5 is a portion provided on the main body frame 1 to which the motor fixing member 4 is attached. The mounting portion 5 includes a first mounting portion 51 provided on the front surface 12a and a second mounting portion 52 provided on the back surface 12b. The first mounting portion 51 is a convex portion that protrudes from the back surface 12b toward the front surface 12a. The second mounting portion 52 is a concave portion that is recessed from the back surface 12b toward the front surface 12a. In this embodiment, the first mounting portion 51 and the second mounting portion 52 are formed integrally on both sides. The first mounting portion 51 and the second mounting portion 52 are positioned in the same circumferential direction. The first mounting portion 51 and the second mounting portion 52 are convex on the front surface 12a side and concave on the back surface 12b side. In this embodiment, the first mounting portion 51 and the second mounting portion 52 are formed by locally bending the fixing portion 12 of the main body frame 1. In addition, the first mounting portion 51 may be formed by locally thickening a portion of the fixed portion 12, or the fixed portion 12 may be made thicker than the example shown in the figure and then a portion of the fixed portion 12 may be locally cut out to form the second mounting portion 52.

[0026] In this embodiment, the number of each of the first mounting portions 51 and the second mounting portions 52 is four. However, this number may be increased or decreased as long as it is the same as the number of the motor fixing legs 42. The first mounting portions 51 are arranged equiangularly apart on the same circumference centered on the central axis C. The second mounting portions 52 are arranged equiangularly apart on the same circumference centered on the central axis C. As shown in FIG. 4, a planar first mounting surface 53 perpendicular to the axial direction is formed at the tip of the first mounting portion 51. FIG. 4 illustrates a dashed line extending radially through the first mounting surface 53. The first mounting surface 53 forms part of the surface 12a of the main body frame 1. The first mounting surface 53 is the surface to which the motor fixing member 4 is attached in the first-purpose ventilation fan 110. The first mounting surface 53 and the minimum inner diameter portion 11a of the bell mouth 11 are aligned in the axial direction. In other words, the position of the first mounting surface 53 in the axial direction is within the range L of the minimum inner diameter portion 11a of the bell mouth 11 when viewed from a direction perpendicular to the axial direction.

[0027] As shown in FIG. 6 , a flat second mounting surface 54 perpendicular to the axial direction is formed on the bottom of the second mounting portion 52. In FIG. 6 , a dashed line extending radially through the second mounting surface 54 is illustrated. The second mounting surface 54 forms part of the back surface 12b of the main body frame 1. The second mounting surface 54 is the surface to which the motor fixing member 4 is attached in the second-purpose ventilation fan 120. The second mounting surface 54 and the minimum inner diameter portion 11a of the bell mouth 11 are aligned in the axial direction. In other words, when viewed from a direction perpendicular to the axial direction, the axial position of the second mounting surface 54 is within the range L of the minimum inner diameter portion 11a of the bell mouth 11. The first mounting surface 53 and the second mounting surface 54 are integrally formed on both sides. The first mounting surface 53 and the second mounting surface 54 are aligned in the circumferential direction.

[0028] Next, the structural differences between the first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 will be described.

[0029] As shown in FIGS. 1, 3, and 4, in the case of the first-purpose ventilation fan 110, the motor fixing leg 42 of the motor fixing member 4 is fixed to the first mounting surface 53 of the first mounting portion 51. The motor 2 and the motor fixing member 4 are fixed to the surface 12a, which is the design surface of the main body frame 1, and are exposed on the design side of the first-purpose ventilation fan 110. Because the first-purpose ventilation fan 110 is installed on a wall of a building, the motor fixing member 4 and the motor 2 are exposed on the indoor side of the building. The axial height of the first mounting portion 51 is such that the trailing edge 37 of the impeller 3 in the first-purpose ventilation fan 110 fits within the minimum inner diameter portion 11a of the bellmouth 11. In other words, the axial position of the first mounting surface 53 is such that the trailing edge 37 of the impeller 3 fits within the range L of the minimum inner diameter portion 11a of the bellmouth 11 when the motor fixing leg 42 is fixed to the first mounting surface 53. In the first-purpose ventilation fan 110, when the electric motor 2 rotates, the impeller 3 attached to the electric motor 2 rotates inside the bell mouth 11, and an exhaust flow from the electric motor 2 toward the bell mouth 11 is generated.

[0030] Here, as shown in FIG. 4 , the shortest axial distance between the first mounting surface 53 and both axial ends 11b, 11c of the minimum inner diameter portion 11a of the bell mouth 11 is defined as Δ1. The axial distance between the first mounting surface 53 and the trailing edge 37 of the impeller 3 is defined as Δ2. In this embodiment, the distance Δ1 is greater than the distance Δ2, but the relationship Δ1 ≥ Δ2 is sufficient. The distance Δ1 refers to the shorter of the axial distance from the first mounting surface 53 to one axial end 11b of the minimum inner diameter portion 11a of the bell mouth 11 and the axial distance from the first mounting surface 53 to the other axial end 11c of the minimum inner diameter portion 11a of the bell mouth 11. In this embodiment, the axial distance from the first mounting surface 53 to the other axial end 11c of the minimum inner diameter portion 11a of the bell mouth 11 is shorter, so this distance is defined as the distance Δ1.

[0031] As shown in Figures 2, 5, and 6, in the case of the second-purpose ventilation fan 120, the motor fixing leg 42 of the motor fixing member 4 is fixed to the second mounting surface 54 of the second mounting portion 52. The motor 2 and the motor fixing member 4 are fixed to the back surface 12b, which serves as the product fixing surface of the main body frame 1, and are not exposed on the design side of the second-purpose ventilation fan 120. The second mounting portion 52 has the same depth as the axial height of the first mounting portion 51. The axial position of the second mounting surface 54 is such that, with the motor fixing leg 42 fixed to the second mounting surface 54, the trailing edge 37 of the impeller 3 is within the range L of the minimum inner diameter portion 11a of the bell mouth 11. In the second-purpose ventilation fan 120, when the motor 2 rotates, the impeller 3 attached to the motor 2 rotates inside the bell mouth 11, generating an airflow from the motor 2 toward the bell mouth 11. The first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 have the same mounting direction of the impeller 3 to the motor 2, without reversing the impeller 3 relative to the motor 2. The first-purpose ventilation fan 110 and the second-purpose ventilation fan 120 also have the same rotation direction of the motor 2 itself.

[0032] Here, as shown in FIG. 6 , the shortest axial distance between the second mounting surface 54 and both axial ends 11b, 11c of the minimum inner diameter portion 11a of the bell mouth 11 is defined as Δ3. The axial distance between the second mounting surface 54 and the trailing edge 37 of the impeller 3 is defined as Δ4. In the present embodiment, the distance Δ3 is greater than the distance Δ4, but it is sufficient that the relationship Δ3 ≥ Δ4 holds. The distance Δ3 refers to the shorter of the axial distance from the second mounting surface 54 to one axial end 11b of the minimum inner diameter portion 11a of the bell mouth 11 and the axial distance from the second mounting surface 54 to the other axial end 11c of the minimum inner diameter portion 11a of the bell mouth 11. In the present embodiment, the axial distance from the second mounting surface 54 to one axial end 11b of the minimum inner diameter portion 11a of the bell mouth 11 is shorter, and so this distance is defined as the distance Δ3.

[0033] Next, the effects of the ventilation fan 100 according to this embodiment will be described.

[0034] In this embodiment, as shown in FIGS. 1 and 2 , the mounting portion 5 includes a first mounting portion 51 provided on the front surface 12 a and a second mounting portion 52 provided on the back surface 12 b, and is configured to allow selection between a first-purpose ventilation fan 110 in which the motor fixing member 4 is attached to the first mounting portion 51 and a second-purpose ventilation fan 120 in which the motor fixing member 4 is attached to the second mounting portion 52. With this configuration, when the motor fixing member 4 is attached to the first mounting portion 51, the motor 2 and the motor fixing member 4 are exposed on the design side of the first-purpose ventilation fan 110. On the other hand, when the motor fixing member 4 is attached to the second mounting portion 52, the motor 2 and the motor fixing member 4 are not exposed on the design side of the second-purpose ventilation fan 120. Therefore, whether the motor 2 and the motor fixing member 4 are exposed can be changed depending on the application of the ventilation fan 100.

[0035] 1 and 2, in this embodiment, the exposed or unexposed state of the motor 2 and the motor fixing member 4 can be changed depending on the application of the ventilation fan 100 simply by attaching the motor fixing member 4 to the first mounting portion 51 or the second mounting portion 52. Therefore, the same parts can be used even when the exposed or unexposed state of the motor 2 and the motor fixing member 4 is changed. Therefore, the standardization of parts can reduce manufacturing costs.

[0036] 4 and 6, in this embodiment, the mounting portion 5 is configured so that the trailing edge 37 of the impeller 3 fits into the minimum inner diameter portion 11a of the bellmouth 11 in both the first-purpose ventilation fan 110 and the second-purpose ventilation fan 120. More specifically, the first mounting portion 51 is a convex portion that protrudes from the back surface 12b toward the front surface 12a and has an axial height that allows the trailing edge 37 of the impeller 3 in the first-purpose ventilation fan 110 to fit into the minimum inner diameter portion 11a of the bellmouth 11, and the second mounting portion 52 is a concave portion that is recessed from the back surface 12b toward the front surface 12a and has a depth that is the same as the axial height of the convex portion. With this configuration, in the case of a first-purpose ventilation fan 110 in which the motor fixing member 4 is attached to the first mounting surface 53 of the first mounting portion 51, the trailing edge 37 of the impeller 3 fits within the minimum inner diameter portion 11a of the bell mouth 11, and therefore, in the case of a second-purpose ventilation fan 120 in which the motor fixing member 4 is attached to the second mounting surface 54 of the second mounting portion 52, which has the same depth as the axial height of the first mounting portion 51, the trailing edge 37 of the impeller 3 also fits within the minimum inner diameter portion 11a of the bell mouth 11. Therefore, a ventilation fan 100 with good air blowing efficiency can be obtained even when changing whether or not the motor 2 and motor fixing member 4 are exposed.

[0037] In this embodiment, as shown in Fig. 4, in the case of a first-purpose ventilation fan 110 in which the motor fixing member 4 is attached to the first mounting surface 53 of the first mounting portion 51, the axial position of the first mounting surface 53 is within the range L of the minimum inner diameter portion 11a of the bellmouth 11 when viewed from a direction perpendicular to the axial direction, and the relationship Δ1 ≧ Δ2 is satisfied. Also, as shown in Fig. 6, in the case of a second-purpose ventilation fan 120 in which the motor fixing member 4 is attached to the second mounting surface 54 of the second mounting portion 52, the axial position of the second mounting surface 54 is within the range L of the minimum inner diameter portion 11a of the bellmouth 11 when viewed from a direction perpendicular to the axial direction, and the relationship Δ3 ≧ Δ4 is ​​satisfied. With these configurations, the trailing edge 37 of the impeller 3 is located within the minimum inner diameter portion 11a of the bellmouth 11 in both the first-purpose ventilation fan 110 and the second-purpose ventilation fan 120. Therefore, even when the electric motor 2 and the electric motor fixing member 4 are exposed or not, the ventilation fan 100 can have good air blowing efficiency.

[0038] Next, a modification of the ventilation fan 100 according to the present embodiment will be described.

[0039] In this embodiment, as shown in Figures 4 and 6, the first mounting surface 53 and the second mounting surface 54 are formed integrally on the front and back sides, but they do not have to be formed integrally on the front and back sides. That is, the first mounting surface 53 and the second mounting surface 54 may be offset in the circumferential direction. In other words, the first mounting surface 53 and the second mounting surface 54 may be formed independently with their relative positions offset from each other on the same circumference on the front and back sides of the main body frame 1. Even in this case, a structure can be realized in which the trailing edge 37 of the impeller 3 is within the range L of the minimum inner diameter portion 11a of the bell mouth 11, regardless of whether the motor fixing member 4 is attached to the first mounting surface 53 or the second mounting surface 54.

[0040] Embodiment 2 Next, a ventilation fan 100A according to a second embodiment will be described with reference to FIGS. 7 to 10. FIG. 7 is a perspective view showing the appearance of the ventilation fan suitable for ventilation purposes according to the second embodiment. FIG. 8 is a view showing an impeller 3A of the ventilation fan suitable for ventilation purposes according to the second embodiment, as viewed from the negative pressure surface 32 of the impeller 3A. FIG. 9 is a projection view showing the impeller 3A of the ventilation fan suitable for ventilation purposes according to the second embodiment, as viewed from a direction perpendicular to the axial direction of the impeller 3A shown in FIG. 8. FIG. 10 is a projection view showing another impeller 3A of the ventilation fan suitable for ventilation purposes according to the second embodiment, as viewed from a direction perpendicular to the axial direction. This embodiment differs from the first embodiment in that multiple types of impellers 3A with different axial heights H can be selected and multiple types of first mounting portions 51A with different axial heights are provided. Note that in the second embodiment, parts that overlap with those in the first embodiment are designated by the same reference numerals and will not be described again.

[0041] The first-purpose ventilation fan 110A according to the second embodiment is a ventilation fan that can combine one type of impeller 3A selected from multiple types of impellers 3A with different axial heights H with one type of first mounting portion 51A selected from multiple types of first mounting portions 51A with different axial heights. As shown in FIGS. 9 and 10 , the impeller 3A can be selected from multiple types with different axial heights H. The axial height H of the impeller 3A is the axial distance from the trailing edge 37 of the impeller 3A to the impeller fixing surface 38. The impeller fixing surface 38 refers to the surface of the boss portion 39 fixed to the shaft 21 of the impeller 3A that is closest to the electric motor 2.

[0042] 7, the first mounting portion 51A can be selected from a variety of types having different axial heights. The first-purpose ventilation fan 110A is configured so that, with the motor fixing member 4 attached to one type of first mounting portion 51A selected from the plurality of types of first mounting portion 51A, the trailing edge 37 of one type of impeller 3A selected from the plurality of types of impellers 3A fits into the minimum inner diameter portion 11a of the bell mouth 11. The first mounting portion 51A is configured so that the trailing edge 37 of each of the plurality of types of impellers 3A fits into the minimum inner diameter portion 11a of the bell mouth 11 in the first-purpose ventilation fan 110A.

[0043] The first mounting portion 51A includes a protruding portion 55 and a flat portion 56. The protruding portion 55 is the same as the protruding portion of the first mounting portion 51 of the first embodiment shown in FIGS. 1 and 3. The flat portion 56 has a flat first mounting surface 57 that is perpendicular to the axial direction. The axial height of the flat portion 56 is lower than the height of the protruding portion 55. In the case of the first-purpose ventilation fan 110A in which the motor fixing member 4 is attached to the surface 12a, the axial position of the first mounting surface 57 of the flat portion 56 is located on the side farther away from the motor 2 than the axial position of the first mounting surface 53 of the protruding portion 55.

[0044] Next, the effects of the ventilation fan 100A according to this embodiment will be described.

[0045] In some cases, the ventilation fan 100A needs to be adapted to the installation location by adjusting the airflow volume appropriately to suit the environment in which it is installed, such as the size of the area to be ventilated and the size of the equipment to be cooled. In such cases, one method for adjusting the airflow volume of the ventilation fan 100A is to replace the impeller 3A with one having a different axial height H on the shaft 21 of the electric motor 2, as shown in FIGS. 8 and 9 . However, if the axial height H of the impeller 3A differs before and after replacement, the trailing edge 37 of the impeller 3A before replacement may not be within the range L of the minimum inner diameter portion 11a of the bell mouth 11. In such cases, airflow efficiency will be poor, and components such as the motor fixing member 4 must be modified so that the trailing edge 37 is within the range L of the minimum inner diameter portion 11a of the bell mouth 11.

[0046] In this regard, in the present embodiment, the ventilation fan 100A can combine one type of impeller 3A selected from multiple types of impellers 3A having different axial heights H with one type of first mounting portion 51A selected from multiple types of first mounting portion 51A having different axial heights. Furthermore, in the present embodiment, the ventilation fan 100A is configured so that, when the motor fixing member 4 is attached to the one type of first mounting portion 51A selected from the multiple types of first mounting portion 51A, the trailing edge 37 of the one type of impeller 3A selected from the multiple types of impellers 3A fits within the minimum inner diameter portion 11a of the bell mouth 11. In other words, the first mounting portion 51A is configured so that the trailing edge 37 of each of the multiple types of impellers 3A fits within the minimum inner diameter portion 11a of the bell mouth 11 in the first-purpose ventilation fan 110A. With these configurations, regardless of which of multiple types of impellers 3A with different axial heights H is attached to the ventilation fan 100A, the trailing edge 37 of the impeller 3A will be within the range L of the minimum inner diameter portion 11a of the bellmouth 11, resulting in a ventilation fan 100A with good air-blowing efficiency. Therefore, a ventilation fan 100A with good air-blowing efficiency can be obtained, while also reducing manufacturing costs by adjusting the air volume of the ventilation fan 100A and standardizing parts.

[0047] Here, assume that the axial height H of the impeller 3A of the first-purpose ventilation fan 110A shown in FIG. 10 is lower than the axial height of the impeller 3 of the first-purpose ventilation fan 110 shown in FIGS. 1 and 3, and that the impeller 3 is to be replaced with the impeller 3A. The motor fixing member 4 of the first-purpose ventilation fan 110 equipped with the impeller 3 before replacement is attached to the first mounting surface 53 of the convex portion 55. The motor fixing member 4 of the first-purpose ventilation fan 110A equipped with the replaced impeller 3A is attached to the first mounting surface 57 of the flat portion 56. The axial distance between the first mounting surface 57 of the flat portion 56 and the first mounting surface 53 of the convex portion 55 is set to be the same as the difference between the axial height of the impeller 3 before replacement and the axial height H of the replaced impeller 3A. This configuration can achieve the above-described effects.

[0048] Next, a modification of the ventilation fan 100A according to the present embodiment will be described.

[0049] In the present embodiment, the plurality of types of first mounting portions 51A are configured by convex portions 55 having a difference in height in the axial direction and flat portions 56, but the plurality of types of first mounting portions 51A may be configured only by convex portions 55 having a difference in height in the axial direction. That is, the plurality of types of first mounting portions 51A may be a plurality of types of convex portions that protrude in the direction from back surface 12b toward front surface 12a and have different axial heights.

[0050] While the present embodiment illustrates the first-purpose ventilation fan 110A, the configuration of the second embodiment may also be applied to the second-purpose ventilation fan 120. That is, the second mounting portion 52 may be configured so that the trailing edges 37 of the multiple types of impellers 3A in the second-purpose ventilation fan 120 fit within the minimum inner diameter portion 11a of the bellmouth 11. When the configuration of the second embodiment is applied to the second-purpose ventilation fan 120, the multiple types of second mounting portions 52 may be configured with recessed portions and flat portions that have a difference in height in the axial direction. Alternatively, the multiple types of second mounting portions 52 may be configured only with recessed portions that have a difference in height in the axial direction. That is, the multiple types of second mounting portions 52 may be multiple types of recessed portions that are recessed in a direction from the back surface 12b to the front surface 12a and have depths that are the same as the axial heights of the multiple types of protruding portions 55.

[0051] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention. [Explanation of symbols]

[0052] 1 main body frame, 2 electric motor, 3, 3A impeller, 4 electric motor fixing member, 5 mounting portion, 11 bell mouth, 11a minimum inner diameter portion, 11b one end portion, 11c other end portion, 12 fixing portion, 12a surface, 12b back surface, 21 shaft, 31 pressure surface, 32 suction surface, 33 leading edge, 34 trailing edge, 35 outer edge, 36 inner edge, 37 trailing edge end, 38 impeller fixing surface, 39 boss portion, 41 electric motor fixing frame, 42 electric motor fixing leg, 43 flange portion, 51, 51A first fixing portion, 52 second fixing portion, 53, 57 first fixing surface, 54 second fixing surface, 55 convex portion, 56 flat portion, 100, 100A ventilation fan, 110, 110A first purpose ventilation fan, 120 Second-purpose ventilation fan, B fixing device, C central axis, H height, L range, X1, X2 air flow direction, Y1, Y2 rotation direction, Δ1, Δ2, Δ3, Δ4 distance.

Claims

1. a main body frame having a cylindrical bell mouth whose inner diameter varies and a fixing portion extending radially outward from an outer circumferential surface of the bell mouth; an electric motor disposed apart from the bell mouth in the axial direction of the bell mouth; an impeller attached to the electric motor and rotating with the rotation of the electric motor to generate an airflow; an electric motor fixing member that connects the main body frame and the electric motor; a mounting portion provided on the fixing portion of the main body frame and to which the electric motor fixing member is attached; Equipped with the main body frame has a front surface facing one side in the axial direction and a back surface facing the other side in the axial direction, the mounting portion includes a first mounting portion provided on the front surface and a second mounting portion provided on the back surface, The motor fixing member is configured to be selectable between a first-purpose ventilation fan in which the motor fixing member is attached to the first mounting portion and a second-purpose ventilation fan in which the motor fixing member is attached to the second mounting portion, The mounting portion is configured so that the rear end edge of the impeller fits into the smallest inner diameter portion of the bell mouth in both the first-purpose ventilation fan and the second-purpose ventilation fan.

2. the first attachment portion is a protrusion that protrudes from the back surface toward the front surface, The ventilation fan according to claim 1 , wherein the second attachment portion is a recess that is recessed in a direction from the rear surface toward the front surface.

3. a main body frame having a cylindrical bell mouth whose inner diameter varies; an electric motor disposed apart from the bell mouth in the axial direction of the bell mouth; an impeller attached to the electric motor and rotating with the rotation of the electric motor to generate an airflow; an electric motor fixing member that connects the main body frame and the electric motor; a mounting portion provided on the main body frame to which the motor fixing member is attached; Equipped with the main body frame has a front surface facing one side in the axial direction and a back surface facing the other side in the axial direction, the mounting portion includes a first mounting portion provided on the front surface and a second mounting portion provided on the back surface, The motor fixing member is configured to be selectable between a first-purpose ventilation fan in which the motor fixing member is attached to the first mounting portion and a second-purpose ventilation fan in which the motor fixing member is attached to the second mounting portion, the first attachment portion is a convex portion that protrudes from the back surface toward the front surface and has a height in the axial direction that allows a rear end edge of the impeller in the first-purpose ventilation fan to fit into a minimum inner diameter portion of the bell mouth, The ventilation fan is characterized in that the second mounting portion is a recess that is recessed in a direction from the back surface toward the front surface and has a depth equal to the axial height of the protrusion.

4. a main body frame having a cylindrical bell mouth whose inner diameter varies; an electric motor disposed apart from the bell mouth in the axial direction of the bell mouth; an impeller attached to the electric motor, which rotates with the rotation of the electric motor to generate an airflow, and which can be selected from a plurality of impellers having different axial heights; an electric motor fixing member that connects the main body frame and the electric motor; a mounting portion provided on the main body frame to mount the motor fixing member, the mounting portion being selectable from a plurality of mounting portions having different heights in the axial direction; Equipped with the main body frame has a front surface facing one side in the axial direction and a back surface facing the other side in the axial direction, the mounting portion includes a first mounting portion provided on the front surface and a second mounting portion provided on the back surface, The motor fixing member is configured to be selectable between a first-purpose ventilation fan in which the motor fixing member is attached to the first mounting portion and a second-purpose ventilation fan in which the motor fixing member is attached to the second mounting portion, the mounting portion is configured so that the rear end edge of the impeller fits within the minimum inner diameter portion of the bell mouth in both the first-purpose ventilation fan and the second-purpose ventilation fan, and so that the rear end edge of each of the plurality of types of impeller fits within the minimum inner diameter portion of the bell mouth.

5. the first attachment portion is a protrusion that protrudes from the back surface toward the front surface, The ventilation fan according to claim 4 , wherein the second attachment portion is a recess that is recessed in a direction from the rear surface toward the front surface.

6. a main body frame having a cylindrical bell mouth whose inner diameter varies; an electric motor disposed apart from the bell mouth in the axial direction of the bell mouth; an impeller attached to the electric motor, which rotates with the rotation of the electric motor to generate an airflow, and which can be selected from a plurality of impellers having different axial heights; an electric motor fixing member that connects the main body frame and the electric motor; a mounting portion provided on the main body frame to mount the motor fixing member, the mounting portion being selectable from a plurality of mounting portions having different heights in the axial direction; Equipped with the main body frame has a front surface facing one side in the axial direction and a back surface facing the other side in the axial direction, the mounting portion includes a first mounting portion provided on the front surface and a second mounting portion provided on the back surface, The motor fixing member is configured to be selectable between a first-purpose ventilation fan in which the motor fixing member is attached to the first mounting portion and a second-purpose ventilation fan in which the motor fixing member is attached to the second mounting portion, the first mounting portion includes a plurality of types of protrusions that protrude from the back surface toward the front surface and have different heights in the axial direction, the second mounting portion includes a plurality of recesses recessed in a direction from the back surface toward the front surface and having depths equal to the heights of the plurality of protrusions in the axial direction, the first mounting portion is configured so that rear end edges of the plurality of types of impellers in the first-purpose ventilation fan fit within the minimum inner diameter portion of the bell mouth, the second mounting portion is configured so that the rear end edges of the plurality of types of impellers in the second-purpose ventilation fan fit within the minimum inner diameter portion of the bell mouth.

7. A main body frame having a cylindrical bell mouth whose inner diameter changes; an electric motor disposed apart from the bell mouth in the axial direction of the bell mouth; an impeller attached to the electric motor and rotating with the rotation of the electric motor to generate an airflow; an electric motor fixing member that connects the main body frame and the electric motor; a mounting portion provided on the main body frame to which the motor fixing member is attached; Equipped with the main body frame has a front surface facing one side in the axial direction and a back surface facing the other side in the axial direction, the mounting portion includes a first mounting portion provided on the front surface and a second mounting portion provided on the back surface, The motor fixing member is configured to be selectable between a first-purpose ventilation fan in which the motor fixing member is attached to the first mounting portion and a second-purpose ventilation fan in which the motor fixing member is attached to the second mounting portion, the mounting portion is configured so that a rear end edge of the impeller fits into a minimum inner diameter portion of the bell mouth in both the first-purpose ventilation fan and the second-purpose ventilation fan, the first attachment portion is a protrusion that protrudes from the back surface toward the front surface, The ventilation fan is characterized in that the second mounting portion is a recess that is recessed in a direction from the back surface toward the front surface.

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