WO2023181193A1

WO2023181193A1 - Impeller and blower

Info

Publication number: WO2023181193A1
Application number: PCT/JP2022/013588
Authority: WO
Inventors: 一輝岡本; 勇児秋場; 和真宮本; 友祐澤野; 周平横山
Original assignee: 三菱電機株式会社
Priority date: 2022-03-23
Filing date: 2022-03-23
Publication date: 2023-09-28
Also published as: JPWO2023181193A1

Abstract

This impeller (3) has a main plate (6) in which is formed a main plate through-hole (6e) through which a shaft (2a) is inserted, and a plurality of vanes (7) that are provided at intervals therebetween along the outer circumferential edge of the main plate (6) and extend in the axial direction of the shaft (2a). On a surface of the main plate (6) that faces one side in the axial direction, there are formed: a contact part (6g) that is provided at a position spaced away from the main plate through-hole (6e) in a radial direction that is a direction perpendicular to the axial direction; and a separation part (6h) that is provided from the main plate through-hole (6e) up to the contact part (6g) and is positioned on one side along the axial direction from the contact part (6g).

Description

impeller and blower

The present disclosure relates to an impeller including a main plate and a plurality of blades, and a blower including the impeller.

The impeller of the blower includes a main plate that rotates as the motor rotates, and a plurality of blades that are spaced apart from each other along the outer periphery of the main plate. The main plate is attached to the motor shaft. Hereinafter, the direction parallel to the shaft of the motor will be referred to as the axial direction. Generally, the axial position of the main plate on the shaft is fixed using a fixing member such as a washer that is passed through the motor shaft.

In the impeller of such a blower, when the electromagnetic vibration caused by the motor as an excitation source matches the natural frequency of the impeller, resonance occurs, resulting in noise. As a countermeasure for reducing noise caused by resonance, a technique is known that uses a damping material to reduce the propagation of vibrations from a motor to an impeller, as disclosed in Patent Document 1, for example. In the technique disclosed in Patent Document 1, the main plate is sandwiched between two damping materials in the axial direction. Each damping material consists of rubber and two plates sandwiching the rubber.

Japanese Patent Application Publication No. 7-103191

In the technology disclosed in Patent Document 1, by using a damping material, it is possible to reduce the propagation of vibration from the motor to the impeller and reduce resonance, but the number of parts and manufacturing steps increase. There are problems like this.

The present disclosure has been made in view of the above, and aims to provide an impeller that can reduce resonance without using a damping material.

In order to solve the above-mentioned problems and achieve the objects, an impeller according to the present disclosure includes a main plate having a main plate insertion hole into which a shaft is inserted, and a main plate provided at intervals along the outer periphery of the main plate. and a plurality of wings extending in the axial direction of the shaft. On the surface of the main plate facing one side along the axial direction, there is a contact part provided at a position away from the main plate insertion hole in the radial direction, which is a direction perpendicular to the axial direction, and a contact part provided from the main plate insertion hole to the contact part. A separation part is provided and located on the other side of the contact part along the axial direction.

The impeller according to the present disclosure has the effect that resonance can be reduced without using a damping material.

A perspective view showing a blower according to Embodiment 1 A cross-sectional view taken along the line II-II shown in Figure 1. A perspective view showing an impeller according to Embodiment 1 A perspective view showing a motor and a fixing member according to Embodiment 1 2 is a cross-sectional view showing a blower according to a comparative example, and corresponds to a cross-sectional view taken along the line II-II shown in FIG. 1. A perspective view showing an impeller according to a comparative example FIG. 2 is a perspective view showing a blower according to a second embodiment, and a perspective view showing a motor and a fixing member according to the second embodiment. 2 is a cross-sectional view showing the blower according to the second embodiment, and corresponds to the cross-sectional view taken along the line II-II shown in FIG. 1. A perspective view showing a fixing member according to a modification of the second embodiment 2 is a cross-sectional view showing the blower according to Embodiment 3, and corresponds to the cross-sectional view taken along the line II-II shown in FIG. 1. A perspective view showing an impeller according to Embodiment 3 In the blower according to Embodiment 3, this is a graph showing the relationship between the amount of axial deformation in the impeller and the natural frequency when the radial dimension of the fixed member is changed, and is a graph based on frequency response analysis. In the blower according to Embodiment 3, this is a graph showing the relationship between the amount of deformation in the circumferential direction of the impeller and the natural frequency when the radial dimension of the fixed member is changed, and is a graph based on frequency response analysis. 2 is a sectional view showing a blower according to Modification 1 of Embodiment 3, and corresponds to a sectional view taken along line II-II shown in FIG. 1. A perspective view showing an impeller according to Modification 1 of Embodiment 3 2 is a cross-sectional view showing a blower according to a second modification of the third embodiment, and corresponds to a cross-sectional view taken along the line II-II shown in FIG. 1. 2 is a sectional view showing the blower according to Embodiment 4, and corresponds to the sectional view taken along the line II-II shown in FIG. 1. A perspective view showing an impeller according to Embodiment 4 A perspective view showing an impeller according to Modification 1 of Embodiment 4 A perspective view showing an impeller according to Modification 2 of Embodiment 4

Below, an impeller and a blower according to an embodiment will be described in detail based on the drawings.

Embodiment 1.
FIG. 1 is a perspective view showing a blower 1 according to the first embodiment. FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. In addition, in FIG. 2, the outer appearance of the housing 2b is shown instead of a cross section for the sake of simplification. As shown in FIGS. 1 and 2, the blower 1 includes a motor 2, an impeller 3, a fixing member 4, and a casing 5. As shown in FIG. 2, the motor 2 has a shaft 2a and a housing 2b. The shaft 2a is formed into a cylindrical shape having a central axis C.

Hereinafter, when explaining the directions of each component of the blower 1, the direction parallel to the central axis C will be referred to as the axial direction, the direction perpendicular to the central axis C will be referred to as the radial direction, and the direction of rotation around the central axis C will be referred to as the circumferential direction. do. The axial direction is the axial direction of the shaft 2a of the motor 2. The radial direction is a direction perpendicular to the axial direction. The circumferential direction is the rotation direction of the shaft 2a. Further, the direction from the shaft 2a toward the housing 2b along the axial direction is defined as one side along the axial direction, and the side opposite to the one along the axial direction is defined as the other side along the axial direction. The axial direction may coincide with the vertical direction, may coincide with the horizontal direction, or may intersect obliquely with respect to the vertical direction and the horizontal direction.

As shown in FIG. 1, the casing 5 is a member that houses the impeller 3. The casing 5 rectifies the airflow generated by the rotation of the impeller 3. The casing 5 has a pair of casing side walls 5a, a casing peripheral wall 5b, and an air outlet 5c.

As shown in FIG. 2, the pair of casing side walls 5a cover the impeller 3 from the axial direction. The pair of casing side wall portions 5a are separated from each other in the axial direction. The impeller 3 is arranged between the pair of casing side walls 5a. A suction port 5d for sucking air into the casing 5 is formed in one of the casing side walls 5a. A fixing hole 5e to which the motor 2 is attached is formed in the other casing side wall portion 5a. The other casing side wall portion 5a serves as a fixing wall for fixing the motor 2. The casing peripheral wall portion 5b covers the impeller 3 from the radial direction.

As shown in FIG. 1, the air outlet 5c is a part for blowing out the airflow generated by the impeller 3 to the outside of the casing 5. The air outlet 5c is formed by extending a part of the casing peripheral wall part 5b and a part of the casing side wall part 5a outward in the radial direction. The casing peripheral wall portion 5b is not provided in the portion of the casing 5 where the air outlet 5c is formed.

As shown in FIG. 2, the motor 2 is a member that rotates an impeller 3 disposed within the casing 5. The housing 2b is a metal member that forms the outer shell of the motor 2. Although not shown in detail, the housing 2b accommodates a stator, a rotor, and the like in addition to a portion of the shaft 2a. A flange portion 2c extending radially outward is formed on the outer peripheral surface of the housing 2b. The housing 2b is inserted into the fixing hole 5e of the casing 5, and is installed across the inside and outside of the casing 5. The flange portion 2c of the housing 2b and the casing side wall portion 5a are superimposed on each other and fixed with bolts or the like (not shown).

The suction port 5d and the fixing hole 5e are separated from each other in the axial direction. The remainder of the shaft 2a protrudes to the outside of the housing 2b. A main plate 6 of the impeller 3, which will be described later, is attached to a portion of the shaft 2a located outside the housing 2b. The main plate 6 rotates as the shaft 2a rotates.

The impeller 3 is a member that is rotated by the motor 2 with the central axis C as a rotation axis. As the impeller 3 rotates, air sucked in from the suction port 5d becomes an airflow and is blown out of the casing 5 from the blowout port 5c. The impeller 3 is made of, for example, metal or resin.

FIG. 3 is a perspective view showing the impeller 3 according to the first embodiment. As shown in FIG. 3, the impeller 3 includes a main plate 6, a plurality of blades 7, and a reinforcing ring 8. The main plate 6 has a circular shape when viewed along the axial direction. The plurality of wings 7 are provided along the outer peripheral edge of the main plate 6 at intervals. Each of the plurality of blades 7 extends in the axial direction. The reinforcing ring 8 has an annular shape when viewed along the axial direction. The reinforcing ring 8 is provided at a position apart from the main plate 6 in the axial direction. The reinforcing ring 8 surrounds the plurality of wings 7.

As shown in FIG. 2, the fixing member 4 is a member that is attached to the shaft 2a between the main plate 6 and the housing 2b, contacts the main plate 6, and fixes the axial position of the impeller 3. The fixing member 4 is made of, for example, metal or resin. The fixing member 4 is, for example, a washer.

FIG. 4 is a perspective view showing the motor 2 and fixing member 4 according to the first embodiment. As shown in FIG. 4, the shape of the fixing member 4 when viewed along the axial direction is circular. A fixed insertion hole 4a through which the shaft 2a is inserted is formed in the center of the fixed member 4. The fixed member 4 has a first fixed shaft end surface 4b and a second fixed shaft end surface 4c. In this embodiment, the first fixed shaft end surface 4b is a surface of the fixed member 4 that faces the other side along the axial direction. In this embodiment, the second fixed shaft end surface 4c is a surface facing one side of the fixed member 4 along the axial direction.

Next, the main plate 6 and the fixing member 4 will be explained in more detail.

As shown in FIG. 2, the main plate 6 has a main plate bottom wall part 6a, a main plate side wall part 6b, and a main plate peripheral wall part 6c. The main plate bottom wall portion 6a extends in the radial direction. The main plate bottom wall portion 6a has a circular shape when viewed along the axial direction. A boss portion 6d that is thicker in the axial direction than other portions is formed at the center of the main plate bottom wall portion 6a. A main plate insertion hole 6e through which the shaft 2a is inserted is formed in the boss portion 6d. The main plate insertion hole 6e is formed to penetrate the main plate bottom wall portion 6a in the axial direction.

The main plate side wall portion 6b extends from the outer peripheral edge of the main plate bottom wall portion 6a toward the housing 2b, and reaches the radially outer side of the housing 2b. The main plate side wall portion 6b is spaced apart from the housing 2b in the radial direction. The main plate side wall portion 6b is formed in a tapered shape whose diameter increases from the outer peripheral edge of the main plate bottom wall portion 6a toward the housing 2b. The main plate peripheral wall portion 6c extends radially outward from the tip edge of the main plate side wall portion 6b. The main plate peripheral wall portion 6c has an annular shape when viewed along the axial direction.

The main plate bottom wall portion 6a has a main plate shaft end face 6f facing toward the fixing member 4. The main plate axial end surface 6f is a surface facing one side of the main plate 6 along the axial direction. A contact portion 6g and a separation portion 6h are formed on the main plate shaft end surface 6f. The contact portion 6g is provided at a position apart from the shaft 2a in the radial direction and contacts the fixing member 4. In this embodiment, the contact portion 6g is an annular plane.

The separating portion 6h is provided from the shaft 2a to the contact portion 6g, and is separated from the fixing member 4 while the contact portion 6g is in contact with the fixing member 4. The separating portion 6h is provided from the edge of the portion of the main plate insertion hole 6e that opens to the main plate shaft end face 6f to a plane that becomes the contact portion 6g. The separation part 6h is located on the other side of the contact part 6g along the axial direction. The separation part 6h is located on the side farther away from the housing 2b than the contact part 6g. In this embodiment, the separating portion 6h is an annular recessed portion recessed from one side toward the other along the axial direction.

Next, the effects of the blower 1 according to this embodiment will be explained.

When the impeller 3 shown in FIG. 2 is rotated by the motor 2, the electromagnetic vibration of the motor 2 is propagated from the shaft 2a to the main plate 6 of the impeller 3 via the fixed member 4, and this electromagnetic vibration is transmitted to the impeller 3. When it matches the natural frequency of No. 3, resonance occurs and noise is generated. At this time, the vibrations generated in the impeller 3 are mainly axial vibrations of shaft vibrations and torsional vibrations in the circumferential direction. Since the main plate 6 holds a plurality of blades 7 and the plurality of blades 7 are provided on the outer peripheral edge of the main plate 6 and the outer peripheral edge of the main plate 6 has a heavy mass, the main plate 6 is an impeller. 3. It has a large effect on the overall vibration. The natural frequency of the impeller 3 can be changed by changing the location of the main plate 6 that contacts the fixed member 4, which affects this vibration.

In this embodiment, the main plate shaft end surface 6f includes a contact portion 6g that is provided at a position radially away from the main plate insertion hole 6e and contacts the fixing member 4, and a contact portion 6g extending from the main plate insertion hole 6e to the contact portion 6g. A separating part 6h is formed so that the contact part 6g is separated from the fixing member 4 while being in contact with the fixing member 4. Thereby, the shortest distance L in the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixing member 4 contact can be changed by appropriately changing the radial dimension of the separating portion 6h. Therefore, by changing the location where the electromagnetic vibration of the motor 2 propagates to the impeller 3, the natural frequency of the impeller 3 can be changed so as to deviate from the resonant frequency. For example, when the operating conditions of the blower 1 change, such as when changing the output of the motor 2 to obtain a larger ventilation air volume, the impeller 3's characteristic The frequency can be removed from the resonant frequency. Therefore, the resonance in the blower 1 can be avoided or the resonance in the blower 1 can be reduced without using a damping material.

Further, in this embodiment, since the shortest distance L in the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixed member 4 contact can be changed, the amplitude of vibration of the impeller 3 can be changed. The contact point between the main plate 6 and the fixing member 4 can be brought close to a large area. Thereby, the vibration of the impeller 3 can be suppressed from becoming dominant.

FIG. 5 is a cross-sectional view showing the blower 10 according to the comparative example, and corresponds to the cross-sectional view taken along the line II-II shown in FIG. 1. FIG. 6 is a perspective view showing an impeller 3 according to a comparative example. As shown in FIGS. 5 and 6, in the blower 10 according to the comparative example, the main plate shaft end surface 6f does not have the separation part 6h, and the main plate shaft end surface 6f and the first fixed shaft end surface 4b are apparently flat. . As shown in FIG. 5, in the blower 10 according to the comparative example, the location where the main plate 6 and the fixed member 4 come into contact changes depending on the flatness of the main plate shaft end surface 6f and the first fixed shaft end surface 4b. Therefore, the shortest distance in the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixed member 4 contact is not clearly determined. Therefore, since the natural frequency of the impeller 3 changes depending on the flatness of the main plate shaft end surface 6f and the first fixed shaft end surface 4b, the location where the electromagnetic vibration of the motor 2 is propagated to the impeller 3 is intentionally changed. It is difficult to intentionally change the natural frequency of the impeller 3.

On the other hand, as shown in FIG. 2, in the present embodiment, a separation part 6h is formed on the main plate shaft end face 6f radially inward from the contact part 6g, so that the main plate 6 and the fixing member 4 can be connected to each other. The main plate 6 and the fixing member 4 are reliably separated from each other on the radially inner side of the point where they contact each other. Therefore, the shortest distance L in the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixed member 4 contact is clearly determined. Therefore, by intentionally changing the location where the electromagnetic vibrations of the motor 2 propagate to the impeller 3, the natural frequency of the impeller 3 can be intentionally changed.

Here, it is desirable that the radially innermost location of the contact points between the main plate 6 and the fixing member 4 be sufficiently spaced radially outward from the central axis C of the shaft 2a. Specifically, when the radius of the shaft 2a is R, it is desirable that the relationship L≧2×R holds true. That is, of the locations where the main plate 6 and the fixing member 4 come into contact, it is desirable that the radially innermost location be located at least twice the radius R of the shaft 2a from the central axis C of the shaft 2a. By doing so, the natural frequency of the impeller 3 can be changed reliably.

In addition, one of the main plate shaft end surface 6f and the fixing member 4 is provided at a position away from the shaft 2a in the radial direction, which is a direction perpendicular to the axial direction. It is only necessary that a contact portion 6g that contacts one or the other is formed. Further, either one of the main plate shaft end surface 6f and the fixing member 4 is provided extending from the shaft 2a to the contact portion 6g, so that the contact portion 6g contacts the other of the main plate shaft end surface 6f and the fixing member 4. It is only necessary that a separating portion 6h be formed to be separated from the other of the main plate shaft end surface 6f and the fixing member 4 in this state.

Embodiment 2.
Next, with reference to FIGS. 7 and 8, a blower 1A according to a second embodiment will be described. This embodiment differs from the first embodiment described above in that a contact portion 4d and a separation portion 4e are provided on the fixing member 4. In addition, in the second embodiment, the same reference numerals are given to the same parts as those in the first embodiment described above, and the description thereof will be omitted. FIG. 7 is a perspective view showing the blower 1A according to the second embodiment, and is a perspective view showing the motor 2 and the fixing member 4 according to the second embodiment. FIG. 8 is a cross-sectional view showing the blower 1A according to the second embodiment, and corresponds to the cross-sectional view taken along the line II-II shown in FIG.

As shown in FIG. 7, in this embodiment, the first fixed shaft end surface 4b is the surface of the fixed member 4 that faces the other side along the axial direction, and the second fixed shaft end surface 4c is the surface of the fixed member 4 that faces the other side along the axial direction. This is the surface facing one side along the axial direction. A plurality of contact portions 4d and a separation portion 4e are formed on the first fixed shaft end surface 4b. As shown in FIG. 8, the second fixed shaft end surface 4c is a plane extending in the radial direction. The first fixed shaft end surface 4b and the second fixed shaft end surface 4c have an asymmetrical shape. That is, the shape of the fixing member 4 is not symmetrical between the front and the back.

As shown in FIG. 8, the contact portion 4d is a protrusion portion 4f that protrudes toward the main plate shaft end surface 6f in this embodiment. The protrusions 4f are provided at positions separated from the shaft 2a in the radial direction and spaced apart from each other along the circumferential direction. The protruding portion 4f has a convex shape on the main plate shaft end face 6f side and a concave shape on the housing 2b side. In this embodiment, the protrusion 4f is provided by locally bending the fixing member 4 without changing the overall plate thickness of the fixing member 4. It may be provided. As shown in FIG. 7, the protruding portion 4f is formed in a truncated conical shape whose diameter decreases as it moves away from the first fixed shaft end surface 4b in the axial direction. The tip of the protrusion 4f is a flat surface extending in the radial direction. The number of protrusions 4f is eight in this embodiment. The eight protrusions 4f are arranged on the same circumference centered on the central axis C.

As shown in FIG. 8, the separating portion 4e is provided extending from the shaft 2a to the protruding portion 4f. The separating portion 4e is separated from the main plate shaft end surface 6f with the protruding portion 4f in contact with the main plate shaft end surface 6f. In this embodiment, the separating portion 4e is a plane extending in the radial direction. The separating portion 4e is provided from the edge of the portion of the fixed insertion hole 4a that opens to the first fixed shaft end surface 4b to the protruding portion 4f. The fixing member 4 may be manufactured by providing a protrusion 4f on a metal plate such as a flat washer, or may be manufactured from a resin material.

This embodiment also provides the same effects as the first embodiment described above. In this embodiment, a contact portion 4d and a separation portion 4e are formed on the first fixed shaft end surface 4b, and the second fixed shaft end surface 4c is a plane extending in the radial direction. As a result, the fixing member 4 is attached to the shaft 2a so that the first fixed shaft end surface 4b faces the main plate shaft end surface 6f, or the second fixed shaft end surface 4c faces the main plate shaft end surface 6f. By simply attaching the fixing member 4 to the shaft 2a, the shortest distance L in the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixing member 4 contact can be changed. Therefore, the natural frequency of the impeller 3 can be easily changed by simply changing the location where the electromagnetic vibration of the motor 2 is propagated to the impeller 3.

Note that FIG. 8 shows a case where the fixing member 4 is attached to the shaft 2a so that the first fixed shaft end surface 4b faces the main plate shaft end surface 6f. When the fixing member 4 is attached to the shaft 2a so that the second fixed shaft end surface 4c faces the main plate shaft end surface 6f, the first fixed shaft end surface 4b is attached to one of the fixing members 4 along the axial direction. The second fixed shaft end surface 4c becomes the surface of the fixed member 4 that faces the other side along the axial direction.

By increasing the radial dimension of the fixing member 4, the shortest radial distance L from the central axis C of the shaft 2a to the point where the main plate shaft end face 6f and the protrusion 4f of the fixing member 4 come into contact can be increased in the radial direction. Can be expanded. However, in order to make the impeller 3 rotatable within the casing 5 while suppressing the enlargement of the blower 1A, the radial dimension of the fixed member 4 must be large enough to fit inside the plurality of blades 7 in the radial direction. It is desirable to set the

Further, the location where the main plate shaft end surface 6f and the protruding portion 4f of the fixing member 4 come into contact serves as a fulcrum around which the impeller 3 rotates. Therefore, in order to suppress the vibration of the impeller 3 and stabilize the rotation of the impeller 3, it is desirable that the main plate shaft end surface 6f and the protruding portion 4f of the fixing member 4 contact each other in their planes.

The fixing member 4 may have the configuration shown in FIG. 9. FIG. 9 is a perspective view showing a fixing member 4 according to a modification of the second embodiment. The contact portion 4d is an annular plane. The contact portion 4d is provided at a position apart from the shaft 2a shown in FIG. 8 in the radial direction and contacts the main plate shaft end surface 6f. The separating portion 4e is a step-like stepped portion that is provided from the shaft 2a to the flat contact portion 4d, and is spaced apart from the main plate shaft end surface 6f as it goes from the outer side to the inner side in the radial direction. Even in this case, the same effects as in the first and second embodiments described above can be achieved.

Embodiment 3.
Next, with reference to FIGS. 10 and 11, a blower 1B according to a third embodiment will be described. In this embodiment, the configurations of a contact portion 6g and a separation portion 6h are different from those in the first embodiment described above. In addition, in Embodiment 3, the same reference numerals are given to the same parts as in Embodiment 1 described above, and the description thereof will be omitted. FIG. 10 is a cross-sectional view showing the blower 1B according to the third embodiment, and corresponds to the cross-sectional view taken along the line II-II shown in FIG. FIG. 11 is a perspective view showing the impeller 3 according to the third embodiment.

As shown in FIG. 10, the central portion of the main plate shaft end surface 6f in the radial direction is formed in a step-like shape that becomes further away from the housing 2b from the outer side toward the inner side in the radial direction. The main plate shaft end surface 6f is provided with a plurality of annular flat surfaces 61 arranged concentrically around the shaft 2a, and a stepped surface 62 connecting adjacent flat surfaces 61. In addition, in this embodiment, the thickness of the main plate bottom wall part 6a is made thicker than the thickness of the main plate side wall part 6b and the main plate peripheral wall part 6c, and the thickness of the main plate bottom wall part 6a is partially changed. A plane 61 is formed.

Each of the plurality of planes 61 extends in the radial direction. Although the number of planes 61 may be increased or decreased as appropriate, it is three in this embodiment. When distinguishing the three planes 61, they are referred to as a plane 61a, a plane 61b, and a plane 61c in order from the outside in the radial direction to the inside.

The stepped surface 62 extends in the axial direction. The stepped surface 62 connects the inner peripheral edge of the adjacent flat surface 61 and the outer peripheral edge of the flat surface 61. The number of stepped surfaces 62 is two in this embodiment. The number of stepped surfaces 62 increases or decreases depending on the number of flat surfaces 61. When distinguishing the two stepped surfaces 62, they are referred to as a stepped surface 62a and a stepped surface 62b in order from the one closest to the housing 2b in the axial direction. The stepped surface 62a connects the inner circumferential edge of the plane 61a and the outer circumferential edge of the plane 61b. The stepped surface 62b connects the inner circumferential edge of the plane 61b and the outer circumferential edge of the plane 61c. The step surface 62b is located radially inner than the step surface 62a.

The more the plurality of planes 61 are located on the inner side in the radial direction, the further apart they are from the housing 2b in the axial direction. In other words, when the central axis C of the shaft 2a is the normal line and the plane passing through the housing 2b is the reference plane S, the axial distance D between the plane 61 and the reference plane S is Among them, the one located on the inner side in the radial direction is longer. Note that in FIG. 10, only the distance D in the axial direction between the plane 61a and the reference plane S is illustrated.

Although the fixing member 4 is in contact with the plane 61a in this embodiment, it may be in contact with the plane 61b. That is, by changing the radial dimension of the fixing member 4, it is possible to bring the fixing member 4 into contact with the plane 61a, and it is also possible to bring the fixing member 4 into contact with the plane 61b.

When the fixing member 4 is brought into contact with the flat surface 61a, the flat surface 61a becomes the contact portion 6g, and the portion of the main plate shaft end surface 6f that is radially inner than the flat surface 61a becomes the separation portion 6h. On the other hand, when the fixing member 4 is brought into contact with the flat surface 61b, the flat surface 61b becomes the contact portion 6g, and the portion of the main plate shaft end surface 6f that is radially inner than the flat surface 61b becomes the separation portion 6h. In this embodiment, one of the plurality of planes 61a and 61b serves as the contact portion 6g.

This embodiment also provides the same effects as the first embodiment described above. In the present embodiment, the plurality of planes 61 provided on the main plate shaft end surface 6f are such that the inner side in the radial direction is further away from the casing 2b in the axial direction, and one of the plurality of planes 61 is located at the contact portion. It will be 6g. Thereby, by changing the radial dimension of the fixing member 4, the shortest distance L in the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixing member 4 contact can be changed. Therefore, the natural frequency of the impeller 3 can be easily changed by simply changing the location where the electromagnetic vibration of the motor 2 is propagated to the impeller 3.

Here, the effects of this embodiment will be further explained with reference to FIGS. 12 and 13. FIG. 12 is a graph showing the relationship between the amount of axial deformation of the impeller 3 and the natural frequency when the radial dimension of the fixed member 4 is changed in the blower 1B according to the third embodiment, This is a graph obtained by frequency response analysis. FIG. 13 is a graph showing the relationship between the amount of deformation in the circumferential direction of the impeller 3 and the natural frequency when the radial dimension of the fixed member 4 is changed in the blower 1B according to the third embodiment, This is a graph obtained by frequency response analysis. The frequency response analysis shown in FIGS. 12 and 13 was conducted under the conditions that the radial dimension of the impeller 3 in Embodiment 3 was 180 mm, and the axial dimension of the impeller 3 was 100 mm.

From the results shown in FIGS. 12 and 13, the impeller 3 has both an axial vibration mode that vibrates in the axial direction and a torsional vibration mode that vibrates torsionally in the circumferential direction, and the amplitude becomes large at the natural frequency. I understand that. It can also be seen that by changing the radial dimension of the fixed member 4, the natural frequency of the impeller 3 can be changed.

In this embodiment, by increasing the number of flat surfaces 61 that serve as the contact portions 6g shown in FIG. 10, it is possible to finely adjust the location where the main plate 6 and the fixing member 4 come into contact. Further, even when the number of flat surfaces 61 serving as the contact portions 6g is increased, the manufacturing cost can be suppressed due to the simple structure. Furthermore, if a resin material is used for the impeller 3, it is possible to manufacture the impeller 3 and the flat surface 61 by integral molding, so it is possible to suppress an increase in manufacturing costs due to an increase in the number of flat surfaces 61. It is possible.

Note that by increasing the radial dimension of the fixed member 4, the shortest radial distance L from the central axis C of the shaft 2a to the point where the main plate 6 and the fixed member 4 contact can be increased in the radial direction. . However, in order to make the impeller 3 rotatable within the casing 5 while suppressing the enlargement of the blower 1B, the radial dimension of the fixed member 4 and the radial dimension of each of the plurality of planes 61 are as follows. It is desirable to have a size that fits inside the plurality of blades 7 in the radial direction.

The plurality of planes 61 may have the configuration shown in FIGS. 14 and 15. FIG. 14 is a cross-sectional view showing a blower 1C according to the first modification of the third embodiment, and corresponds to the cross-sectional view taken along the line II-II shown in FIG. FIG. 15 is a perspective view showing an impeller 3 according to a first modification of the third embodiment.

As shown in FIGS. 14 and 15, the main plate shaft end surface 6f is provided with a plurality of cylindrical ribs 63 arranged concentrically around the shaft 2a. As shown in FIG. 15, a portion of the main plate shaft end surface 6f other than the rib 63 is a flat surface 64. As shown in FIG. The rib 63 projects further toward the housing 2b than the plane 64. The tip of the rib 63 facing toward the housing 2b is a flat surface 61 that extends in the radial direction. Although the number of ribs 63 may be increased or decreased as appropriate, it is two in this modification. When distinguishing the two ribs 63, they are referred to as a rib 63a and a rib 63b in order from the outside in the radial direction to the inside. The plurality of ribs 63 are axially farther away from the housing 2b as they are located on the inner side in the radial direction. The distance D in the axial direction between each rib 63 and the reference plane S is longer as the rib 63 is located on the inner side in the radial direction. In addition, in FIG. 14, only the distance D in the axial direction between the plane 61 of the rib 63a and the reference plane S is illustrated.

Although the fixing member 4 is in contact with the flat surface 61 of the rib 63a in this modification, it may be in contact with the flat surface 61 of the rib 63b. That is, by changing the radial dimension of the fixing member 4, it is possible to bring the fixing member 4 into contact with the flat surface 61 of the rib 63a, and it is also possible to bring the fixing member 4 into contact with the flat surface 61 of the rib 63b. be.

When the fixing member 4 is brought into contact with the flat surface 61 of the rib 63a, the flat surface 61 of the rib 63a becomes the contact portion 6g, and the portion of the main plate shaft end surface 6f located radially inward from the rib 63a becomes the separation portion 6h. . On the other hand, when the fixing member 4 is brought into contact with the flat surface 61 of the rib 63b, the flat surface 61 of the rib 63b becomes the contact portion 6g, and the portion located radially inward from the rib 63b becomes the separation portion 6h. In this modification, one of the flat surfaces 61 of the plurality of ribs 63a, 63b becomes the contact portion 6g. Even in this case, the same effects as in the first and second embodiments described above can be achieved.

The plurality of planes 61 may have the configuration shown in FIG. 16. FIG. 16 is a sectional view showing a blower 1D according to a second modification of the third embodiment, and corresponds to a sectional view taken along the line II-II shown in FIG. As shown in FIG. 16, a plurality of flat surfaces 61 may be provided by locally bending the main plate 6 while keeping the thickness of the entire main plate 6 constant. The more the plurality of planes 61 are located on the inner side in the radial direction, the further apart they are from the housing 2b in the axial direction.

Embodiment 4.
Next, a blower 1E according to a fourth embodiment will be described with reference to FIGS. 17 and 18. In this embodiment, the configurations of a contact portion 6g and a separation portion 6h are different from those in the first embodiment described above. In the fourth embodiment, the same parts as those in the first embodiment described above are given the same reference numerals and the explanation thereof will be omitted. FIG. 17 is a cross-sectional view showing a blower 1E according to the fourth embodiment, and corresponds to a cross-sectional view taken along the line II-II shown in FIG. FIG. 18 is a perspective view showing the impeller 3 according to the fourth embodiment.

As shown in FIGS. 17 and 18, the main plate shaft end surface 6f is provided with a plurality of ribs 65 that extend radially from the shaft 2a and protrude toward the housing 2b. As shown in FIG. 18, the plurality of ribs 65 are spaced apart from each other in the circumferential direction. Although the number of ribs 65 may be increased or decreased as appropriate, it is six in this embodiment. A plurality of rectangular flat surfaces 66 arranged along the radial direction and a step surface 67 connecting adjacent flat surfaces 66 are provided on the surface of each rib 65 facing the housing 2b. The shape of the surface of each rib 65 facing toward the housing 2b is rotationally symmetrical with the central axis C of the shaft 2a as an axis of symmetry. That is, the positions of the planes 66 of all the ribs 65 in the radial direction are the same.

The plane 66 extends in the radial direction. Although the number of planes 66 may be increased or decreased as appropriate, it is three in this embodiment. When distinguishing the three planes 66, they are referred to as a plane 66a, a plane 66b, and a plane 66c in order from the outside in the radial direction to the inside.

The stepped surface 67 extends in the axial direction. The step surface 67 connects the inner edge of the adjacent plane 66 and the outer edge of the plane 66. The number of stepped surfaces 67 is two in this embodiment. The number of stepped surfaces 67 increases or decreases depending on the number of flat surfaces 66. When distinguishing the two stepped surfaces 67, they are referred to as a stepped surface 67a and a stepped surface 67b in order from the one closest to the housing 2b in the axial direction. The stepped surface 67a connects the inner edge of the plane 66a and the outer edge of the plane 66b. The stepped surface 67b connects the inner edge of the plane 66b and the outer edge of the plane 66c.

As shown in FIG. 17, the plurality of planes 66 are axially farther away from the housing 2b as they are located on the inner side in the radial direction. The distance D in the axial direction between each plane 66 and the reference plane S is longer as the plane 66 is located on the inner side in the radial direction. Note that in FIG. 17, only the distance D in the axial direction between the plane 66a and the reference plane S is illustrated.

Although the fixing member 4 is in contact with the plane 66a in this embodiment, it may be in contact with the plane 66b. That is, by changing the radial dimension of the fixing member 4, it is possible to bring the fixing member 4 into contact with the plane 66a, and it is also possible to bring the fixing member 4 into contact with the plane 66b.

When the fixing member 4 is brought into contact with the flat surface 66a, the flat surface 66a becomes the contact portion 6g, and the portion of the main plate shaft end face 6f that is radially inner than the flat surface 66a becomes the separation portion 6h. On the other hand, when the fixing member 4 is brought into contact with the flat surface 66b, the flat surface 66b becomes the contact portion 6g, and the portion of the main plate shaft end surface 6f that is radially inner than the flat surface 66b becomes the separation portion 6h. In this embodiment, one of the plurality of planes 66a and 66b serves as the contact portion 6g.

The present embodiment can also achieve the same effects as the first, second, and third embodiments described above. In this embodiment, as shown in FIG. 17, the plurality of planes 66 provided on the main plate shaft end surface 6f are such that the radially inner side thereof is further away from the housing 2b in the axial direction. One of the contact portions 66 becomes the contact portion 6g. Thereby, by changing the radial dimension of the fixing member 4, the shortest distance L in the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixing member 4 contact can be changed. Therefore, the natural frequency of the impeller 3 can be easily changed by simply changing the location where the electromagnetic vibration of the motor 2 is propagated to the impeller 3.

In this embodiment, the main plate shaft end surface 6f is provided with a plurality of ribs 65 that extend radially from the shaft 2a and protrude toward the housing 2b. The plurality of planes 66 provided on the facing surfaces are axially farther away from the housing 2b as the planes are located on the inner side in the radial direction. Thereby, the contact point between the main plate 6 and the fixing member 4 can be changed not only in the radial direction but also in the circumferential direction. That is, by providing the main plate shaft end surface 6f with a plurality of ribs 65 that extend radially from the shaft 2a and protrude toward the housing 2b, the main plate 6 and the fixing member 4 are intermittently in contact with each other in the circumferential direction. do. Therefore, the natural frequency of the impeller 3 can be changed more finely.

In this embodiment, by increasing the number of ribs 65 or changing the width of the ribs 65, it is possible to finely adjust the contact point between the main plate 6 and the fixed member 4 in the circumferential direction. The natural frequency of can be changed more precisely. Further, even if the number of ribs 65 is increased or the width of the ribs 65 is made thinner, the manufacturing cost can be kept down because of the simple structure. Furthermore, if a resin material is used for the material of the impeller 3, it is possible to manufacture the impeller 3 and the ribs 65 by integral molding, so it is possible to increase the number of ribs 65 or reduce the width of the ribs 65. It is possible to suppress the increase in manufacturing costs due to this.

As shown in FIG. 19, the shape of the surface of each rib 65 facing toward the housing 2b may be a rotationally asymmetric shape about the central axis C of the shaft 2a. FIG. 19 is a perspective view showing an impeller 3 according to a first modification of the fourth embodiment. As shown in FIG. 19, the positions of the planes 66 of each rib 65 in the radial direction are different from each other. In the illustrated example, ribs 65 having a flat surface 66 on the radially outer portion of the rib 65 and ribs 65 having a flat surface 66 on the radially central portion of the rib 65 are alternately arranged in the circumferential direction. There is. The ribs 65 adjacent to each other in the circumferential direction have flat surfaces 66 offset in the radial direction. In this modification, the point where the rib 65 and the fixing member 4 contact can be changed individually for each rib 65, and the radial direction from the central axis C of the shaft 2a to the point where the main plate 6 and the fixing member 4 make contact The shortest distance L can be changed for each rib 65.

The main plate 6 may have the configuration shown in FIG. 20. FIG. 20 is a perspective view showing an impeller 3 according to a second modification of the fourth embodiment. The main plate side wall 6b is provided with an opening 6i that radially penetrates the main plate side wall 6b. The opening 6i is provided for cooling the motor 2 with air. That is, a portion of the air sucked into the casing 5 from the suction port 5d hits the motor 2 through the opening 6i, thereby cooling the motor 2.

In this modification, the contact point between the main plate 6 and the fixing member 4 can be changed not only in the radial direction but also in the circumferential direction. Therefore, even when the opening 6i is provided in the main plate 6, the location where the electromagnetic vibration of the motor 2 propagates to the impeller 3 is changed, and the natural frequency of the impeller 3 is changed so as to deviate from the resonant frequency. be able to. Therefore, the resonance in the blower 1 can be avoided or the resonance in the blower 1 can be reduced without using a damping material.

The configurations shown in the embodiments above are merely examples, and can be combined with other known techniques, or can be combined with other embodiments, within the scope of the gist. It is also possible to omit or change part of the configuration.

For example, the blowers 1 to 1E according to each of the embodiments described above may be used for ventilation purposes, air conditioning purposes, and other purposes.

In each of the embodiments described above, the case where the impeller 3 is applied to a multi-blade blower is exemplified, but the impeller 3 may be applied to a blower other than a multi-blade blower. That is, the impeller 3 is applicable to a general blower, regardless of whether it is a centrifugal blower or an axial blower.

In each of the embodiments described above, the blowers 1 to 1E are of the single suction type with one suction port 5d, but may be of the double suction type with two suction ports 5d.

1, 1A, 1B, 1C, 1D, 1E, 10 blower, 2 motor, 2a shaft, 2b housing, 2c flange section, 3 impeller, 4 fixing member, 4a fixing insertion hole, 4b first fixed shaft end surface, 4c Second fixed shaft end surface, 4d, 6g contact part, 4e, 6h separation part, 4f protrusion part, 5 casing, 5a casing side wall part, 5b casing peripheral wall part, 5c outlet, 5d suction port, 5e fixing hole, 6 Main plate, 6a Main plate bottom wall, 6b Main plate side wall, 6c Main plate peripheral wall, 6d Boss, 6e Main plate insertion hole, 6f Main plate shaft end face, 6i Opening, 7 Wing, 8 Reinforcement ring, 61, 61a, 61b, 61c , 64, 66, 66a, 66b, 66c plane, 62, 62a, 62b, 67, 67a, 67b step surface, 63, 63a, 63b, 65 rib.

Claims

a main plate having a main plate insertion hole through which the shaft is inserted;
a plurality of wings provided at intervals along the outer periphery of the main plate and extending in the axial direction of the shaft;
A contact portion provided on a surface facing one side along the axial direction of the main plate at a position away from the main plate insertion hole in a radial direction that is perpendicular to the axial direction; An impeller characterized in that a separation part is formed extending over the contact part and located on the other side of the contact part in the axial direction.
A motor having a shaft and a casing that accommodates a portion of the shaft;
a main plate that is attached to a portion of the shaft located outside the housing and rotates as the shaft rotates; and a main plate that is provided at intervals along an outer peripheral edge of the main plate in the axial direction of the shaft. an impeller having a plurality of blades extending to;
a fixing member that is attached to the shaft between the main plate and the housing and contacts the main plate to fix the axial position of the impeller;
a casing that houses the impeller;
Equipped with
The main plate has a main plate axial end face facing the fixing member,
Either one of the main plate shaft end face and the fixing member is provided at a position away from the shaft in a radial direction, which is a direction perpendicular to the axial direction, and one of the main plate shaft end face and the fixing member a contact portion that contacts the other; and a contact portion that is provided from the shaft to the contact portion and contacts the main plate shaft end surface and the fixing member in a state where the contact portion contacts the other of the main plate shaft end surface and the fixing member. A blower characterized in that a separating portion is formed to be separated from one of the two.
The contact portion is an annular plane provided at a position apart from the shaft in the radial direction and comes into contact with the fixing member,
3. The blower according to claim 2, wherein the separation part is a recess that extends from the shaft to the plane and is spaced apart from the fixing member while the plane is in contact with the fixing member.
The contact portion and the separation portion are formed on either one of a surface facing one side along the axial direction and a surface facing the other side along the axial direction of the fixing member,
The blower according to claim 2, wherein the other of the surface of the fixed member facing one direction along the axial direction and the surface facing the other direction along the axial direction is a flat surface.
The contact portions include a plurality of contact portions that are provided at positions apart from the shaft in the radial direction and spaced apart from each other along the circumferential direction, which is the rotational direction of the shaft, and protrude toward the main plate shaft end surface. is the protrusion of
5. The separating portion is a plane provided extending from the shaft to the protruding portion and separating from the main plate shaft end surface while the protruding portion is in contact with the main plate shaft end surface. blower.
The contact portion is an annular plane that is provided at a position apart from the shaft in the radial direction and contacts the main plate shaft end surface,
The separating portion is a stepped portion that is provided from the shaft to the plane and is spaced apart from the main plate shaft end face in the axial direction from the outer side to the inner side in the radial direction. 4. The blower according to item 4.
The main plate shaft end face is provided with a plurality of annular planes arranged concentrically around the shaft,
The plurality of planes are further away from the casing in the axial direction as they are located on the inner side in the radial direction,
The blower according to claim 2, wherein one of the plurality of planes serves as the contact portion.
The main plate shaft end surface is provided with a plurality of ribs that extend radially from the shaft in the radial direction and protrude toward the housing,
A plurality of planes arranged along the radial direction are provided on the surface of each of the ribs facing the casing,
The plurality of planes are further away from the casing in the axial direction as they are located on the inner side in the radial direction,
The blower according to claim 2, wherein one of the plurality of planes serves as the contact portion.
The blower according to claim 8, wherein the shape of the surface of each of the ribs facing toward the housing is rotationally asymmetrical with respect to the central axis of the shaft.