Blower

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

[Technical field]

[0001] The present disclosure relates to a main plate and a plurality of wings. Yes Feather Car This relates to the blower provided. [Background technology]

[0002] The impeller of the blower includes a main plate that rotates with the rotation of the motor, and a number of blades spaced apart from one another along the outer periphery of the main plate. The main plate is attached to the shaft of the motor. Hereinafter, the direction parallel to the motor shaft is referred to as the axial direction. In general, 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.

[0003] In such a blower impeller, when electromagnetic vibrations generated by the motor as an excitation source coincide with the natural frequency of the impeller, resonance occurs and generates noise. As a measure to reduce the noise caused by resonance, for example, a technique is known in which a vibration-damping material is used to reduce the transmission of vibration from the motor to the impeller, as in Patent Document 1. In the technique disclosed in Patent Document 1, the main plate is sandwiched between two vibration-damping materials in the axial direction. Each vibration-damping material is made of rubber and two plates that sandwich the rubber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-103191 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology disclosed in Patent Document 1 uses vibration-damping material to reduce the transmission of vibration from the motor to the impeller, thereby reducing resonance, but it has problems such as an increase in the number of parts and manufacturing man-hours.

[0006] The present disclosure has been made in view of the above, and is capable of reducing resonance without using a vibration-damping material. Blower The purpose is to obtain [Means for solving the problem]

[0007] In order to solve the above problems and achieve the object, the present disclosure relates to Blower teeth, The motor includes a shaft and a housing that houses a part of the shaft, a main plate that is attached to a part of the shaft located outside the housing and rotates with the rotation of the shaft, an impeller having a plurality of blades that are spaced apart from one another along the outer periphery of the main plate and extend in the axial direction of the shaft, 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, and a casing that houses the impeller. The main plate has a main plate shaft end face that faces the fixing member. Either the main plate shaft end face or the fixing member is formed with a contact portion that is provided at a position away from the shaft in the radial direction, which is a direction perpendicular to the axial direction, and that contacts the other of the main plate shaft end face and the fixing member, and a separation portion that is provided from the shaft to the contact portion and that is separated from the other of the main plate shaft end face and the fixing member when the contact portion contacts the other of the main plate shaft end face and the fixing member. Effect of the Invention

[0008] According to this disclosure Blower This provides the effect of reducing resonance without using a vibration-damping material. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a blower according to a first embodiment; [Diagram 2] A cross-sectional view taken along line II-II shown in FIG. [Diagram 3] FIG. 1 is a perspective view showing an impeller according to a first embodiment; [Figure 4] FIG. 1 is a perspective view showing a motor and a fixed member according to a first embodiment; [Diagram 5] FIG. 2 is a cross-sectional view showing a blower according to a comparative example, which corresponds to the cross-sectional view taken along line II-II shown in FIG. [Figure 6] FIG. 1 is a perspective view showing an impeller according to a comparative example. [Figure 7] FIG. 11 is a perspective view showing a blower according to a second embodiment, illustrating a motor and a fixing member according to the second embodiment; [Figure 8] FIG. 11 is a cross-sectional view showing a blower according to a second embodiment, which corresponds to the cross-sectional view taken along line II-II shown in FIG. [Figure 9] FIG. 13 is a perspective view showing a fixing member according to a modified example of the second embodiment. [Figure 10] FIG. 11 is a cross-sectional view showing a blower according to a third embodiment, which corresponds to the cross-sectional view taken along line II-II shown in FIG. [Figure 11] FIG. 13 is a perspective view showing an impeller according to a third embodiment. [Figure 12] FIG. 11 is a graph showing a relationship between an axial deformation amount and a natural frequency of an impeller when a radial dimension of a fixing member is changed in a blower according to a third embodiment, the graph being based on a frequency response analysis. [Figure 13] 13 is a graph showing a relationship between a circumferential deformation amount and a natural frequency of an impeller when a radial dimension of a fixing member is changed in a blower according to a third embodiment, the graph being based on a frequency response analysis. [Figure 14] FIG. 2 is a cross-sectional view showing a blower according to a first modified example of the third embodiment, which corresponds to the cross-sectional view taken along the line II-II shown in FIG. [Figure 15] FIG. 13 is a perspective view showing an impeller according to a first modified example of the third embodiment. [Figure 16] FIG. 2 is a cross-sectional view showing a blower according to a second modification of the third embodiment, which corresponds to the cross-sectional view taken along the line II-II shown in FIG. [Figure 17] FIG. 11 is a cross-sectional view showing a blower according to a fourth embodiment, which corresponds to the cross-sectional view taken along line II-II shown in FIG. [Figure 18] FIG. 13 is a perspective view showing an impeller according to a fourth embodiment. [Figure 19] FIG. 13 is a perspective view showing an impeller according to a first modified example of the fourth embodiment. [Figure 20] FIG. 13 is a perspective view showing an impeller according to a second modification of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The following describes the embodiment. Send The fan will now be described in detail with reference to the drawings.

[0011] Embodiment 1 FIG. 1 is a perspective view showing a blower 1 according to a first embodiment. FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. 1. For simplification, FIG. 2 shows the exterior of a housing 2b rather than a cross-section. 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 includes a shaft 2a and a housing 2b. The shaft 2a is formed in a cylindrical shape having a central axis C.

[0012] Hereinafter, when describing the directions of each component of the blower 1, the direction parallel to the central axis C is referred to as the axial direction, the direction perpendicular to the central axis C is referred to as the radial direction, and the rotation direction around the central axis C is referred to as the circumferential direction. The axial direction is the axial direction of the shaft 2a of the motor 2. The radial direction is the direction perpendicular to the axial direction. The circumferential direction is the rotation direction of the shaft 2a. In addition, the direction from the shaft 2a toward the housing 2b along the axial direction is referred to as one side along the axial direction, and the opposite side of the one side along the axial direction is referred to 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 be oblique to the vertical direction and the horizontal direction.

[0013] 1, the casing 5 is a member that houses the impeller 3. The casing 5 straightens 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.

[0014] As shown in FIG. 2, a pair of casing side walls 5a cover the impeller 3 in the axial direction. The pair of casing side walls 5a are separated from each other in the axial direction. The impeller 3 is disposed between the pair of casing side walls 5a. One of the casing side walls 5a has an inlet 5d for drawing air into the casing 5. The other casing side wall 5a has a fixing hole 5e for mounting the motor 2. The other casing side wall 5a serves as a fixing wall for fixing the motor 2. The casing peripheral wall 5b covers the impeller 3 in the radial direction.

[0015] 1, the air outlet 5c is a portion 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 part of the casing peripheral wall portion 5b and part of the casing side wall portion 5a radially outward. The casing peripheral wall portion 5b is not provided in the portion of the casing 5 where the air outlet 5c is formed.

[0016] As shown in FIG. 2, the motor 2 is a member that rotates the impeller 3 arranged in the casing 5. The housing 2b is a metal member that constitutes the outer shell of the motor 2. Although not specifically shown, the housing 2b accommodates a part of the shaft 2a as well as a stator, a rotor, and the like. A flange portion 2c that extends radially outward is formed on the outer circumferential surface of the housing 2b. The housing 2b is inserted into a 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 overlapped with each other and fixed by bolts (not shown) or the like.

[0017] The suction port 5d and the fixing hole 5e are spaced apart from each other in the axial direction. The remaining part of the shaft 2a protrudes outside the housing 2b. A main plate 6 of the impeller 3, which will be described later, is attached to a part of the shaft 2a located outside the housing 2b. The main plate 6 rotates with the rotation of the shaft 2a.

[0018] The impeller 3 is a member that is rotated by the motor 2 around the central axis C as a rotation axis. As the impeller 3 rotates, air sucked in from the suction port 5d becomes an air flow and is blown out of the casing 5 from the air outlet 5c. The material of the impeller 3 is, for example, metal or resin.

[0019] FIG. 3 is a perspective view showing the impeller 3 according to the first embodiment. As shown in FIG. 3, the impeller 3 has a main plate 6, a plurality of blades 7, and a reinforcing ring 8. The shape of the main plate 6 when viewed in the axial direction is circular. The plurality of blades 7 are provided along the outer periphery of the main plate 6 at intervals from one another. Each of the plurality of blades 7 extends in the axial direction. The shape of the reinforcing ring 8 when viewed in the axial direction is annular. The reinforcing ring 8 is provided at a position separated from the main plate 6 in the axial direction. The reinforcing ring 8 surrounds the periphery of the plurality of blades 7.

[0020] 2, the fixing member 4 is attached to the shaft 2a between the main plate 6 and the housing 2b, and is a member that contacts the main plate 6 to fix the axial position of the impeller 3. The fixing member 4 is made of a material such as metal or resin. The fixing member 4 is, for example, a washer.

[0021] FIG. 4 is a perspective view showing the motor 2 and the fixed member 4 according to the first embodiment. As shown in FIG. 4, the fixed member 4 has a circular shape when viewed along the axial direction. 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 face 4b and a second fixed shaft end face 4c. In this embodiment, the first fixed shaft end face 4b is a surface of the fixed member 4 facing the other side along the axial direction. In this embodiment, the second fixed shaft end face 4c is a surface of the fixed member 4 facing one side along the axial direction.

[0022] Next, the main plate 6 and the fixing member 4 will be described in more detail.

[0023] As shown in FIG. 2, the main plate 6 has a main plate bottom wall portion 6a, a main plate side wall portion 6b, and a main plate peripheral wall portion 6c. The main plate bottom wall portion 6a extends in the radial direction. When viewed along the axial direction, the main plate bottom wall portion 6a has a circular shape. A boss portion 6d that is thicker in the axial direction than other portions is formed in 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 penetrating the main plate bottom wall portion 6a in the axial direction.

[0024] 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 disposed at a distance from the housing 2b in the radial direction. The main plate side wall portion 6b is formed in a tapered shape that expands in diameter 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 from the tip edge of the main plate side wall portion 6b toward the radially outer side. The shape of the main plate peripheral wall portion 6c when viewed along the axial direction is annular.

[0025] The main plate bottom wall portion 6a has a main plate shaft end surface 6f facing the fixed member 4. The main plate shaft end surface 6f is a surface of the main plate 6 facing one side 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 radially separated from the shaft 2a and contacts the fixed member 4. In this embodiment, the contact portion 6g is an annular flat surface.

[0026] The separation portion 6h is provided from the shaft 2a to the contact portion 6g, and is separated from the fixed member 4 with the contact portion 6g in contact with the fixed member 4. The separation portion 6h is provided from the edge of the portion of the main plate insertion hole 6e that opens to the main plate axial end face 6f to the plane that becomes the contact portion 6g. The separation portion 6h is located on the other side along the axial direction than the contact portion 6g. The separation portion 6h is located on the side that is separated from the housing 2b than the contact portion 6g. In this embodiment, the separation portion 6h is an annular recess recessed from one side along the axial direction to the other side.

[0027] Next, the effects of the blower 1 according to this embodiment will be described.

[0028] When the impeller 3 shown in Fig. 2 is rotated by the motor 2, the electromagnetic vibration of the motor 2 is transmitted from the shaft 2a to the main plate 6 of the impeller 3 via the fixed member 4, and when this electromagnetic vibration coincides with the natural frequency of the impeller 3, resonance occurs and noise is generated. At this time, the vibrations generated in the impeller 3 are mainly axial vibration of the shaft vibration and torsional vibration in the circumferential direction. Since the main plate 6 holds multiple blades 7, and the multiple blades 7 are provided on the outer periphery of the main plate 6 and the mass of the outer periphery of the main plate 6 is heavy, the main plate 6 has a large effect on the vibration of the entire impeller 3. The natural frequency of the impeller 3 can be changed by changing the location of contact between the fixed member 4 and the main plate 6, which affects this vibration.

[0029] In this embodiment, the main plate shaft end surface 6f is provided with a contact portion 6g provided at a position radially away from the main plate insertion hole 6e and in contact with the fixed member 4, and a separation portion 6h provided from the main plate insertion hole 6e to the contact portion 6g and separated from the fixed member 4 with the contact portion 6g in contact with the fixed member 4. This allows the radial dimension of the separation portion 6h to be appropriately changed to change 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 each other. Therefore, the location where the electromagnetic vibration of the motor 2 propagates to the impeller 3 can be changed to change the natural frequency of the impeller 3 so as to deviate from the resonance frequency. For example, when the use conditions of the blower 1 change, such as when the output of the motor 2 is changed to obtain a larger ventilation air volume, the natural frequency of the impeller 3 can be deviated from the resonance frequency in response to the change in the electromagnetic vibration of the motor 2. Therefore, it is possible to avoid resonance in the blower 1 or reduce resonance in the blower 1 without using a vibration-damping material.

[0030] In addition, in this embodiment, the minimum 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 each other can be changed, so that the point where the main plate 6 and the fixed member 4 contact each other can be moved closer to an area of ​​the impeller 3 where the vibration amplitude is large. This makes it possible to prevent the vibration of the impeller 3 from becoming dominant.

[0031] FIG. 5 is a cross-sectional view of a blower 10 according to a comparative example, which corresponds to the cross-sectional view taken along line II-II in FIG. 1. FIG. 6 is a perspective view of 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 face 6f does not have a separation portion 6h, and the main plate shaft end face 6f and the first fixed shaft end face 4b are apparently flat. As shown in FIG. 5, in the blower 10 according to the comparative example, the contact point between the main plate 6 and the fixed member 4 varies depending on the flatness of the main plate shaft end face 6f and the first fixed shaft end face 4b. Therefore, the shortest radial distance from the central axis C of the shaft 2a to the contact point between the main plate 6 and the fixed member 4 is not clearly determined. Therefore, since the natural frequency of the impeller 3 changes depending on the flatness of the main plate shaft end face 6f and the first fixed shaft end face 4b, it is difficult to intentionally change the point where the electromagnetic vibration of the motor 2 is transmitted to the impeller 3 and thereby intentionally change the natural frequency of the impeller 3.

[0032] 2, in this embodiment, a separation portion 6h is formed radially inward of the contact portion 6g on the main plate shaft end surface 6f, so that the main plate 6 and the fixed member 4 are reliably separated from each other radially inward of the contact portion between the main plate 6 and the fixed member 4. This clearly determines the shortest radial distance L from the central axis C of the shaft 2a to the contact portion between the main plate 6 and the fixed member 4. This makes it possible to intentionally change the portion where the electromagnetic vibration of the motor 2 propagates to the impeller 3, thereby intentionally changing the natural frequency of the impeller 3.

[0033] Here, it is desirable that the radially innermost point of contact between the main plate 6 and the fixed member 4 is sufficiently separated radially outward from the central axis C of the shaft 2a. Specifically, it is desirable that the relationship L≧2×R be established, where R is the radius of the shaft 2a. In other words, it is desirable that the radially innermost point of contact between the main plate 6 and the fixed member 4 is located at a position at least twice the radius R of the shaft 2a from the central axis C of the shaft 2a. In this way, the natural frequency of the impeller 3 can be reliably changed.

[0034] Either one of the main shaft end surface 6f and the fixed member 4 may have a contact portion 6g formed at a position separated from the shaft 2a in the radial direction, which is a direction perpendicular to the axial direction, and in contact with the other of the main shaft end surface 6f and the fixed member 4. Either one of the main shaft end surface 6f and the fixed member 4 may have a separation portion 6h formed from the shaft 2a to the contact portion 6g and separated from the other of the main shaft end surface 6f and the fixed member 4 with the contact portion 6g in contact with the other of the main shaft end surface 6f and the fixed member 4.

[0035] Embodiment 2 Next, a blower 1A according to a second embodiment will be described with reference to Figs. 7 and 8. This embodiment differs from the first embodiment in that a contact portion 4d and a separation portion 4e are provided on a fixed member 4. In the second embodiment, the same reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted. Fig. 7 is a perspective view showing a blower 1A according to the second embodiment, and is a perspective view showing a motor 2 and a fixed member 4 according to the second embodiment. Fig. 8 is a cross-sectional view showing a blower 1A according to the second embodiment, and is a cross-sectional view corresponding to the cross-sectional view taken along line II-II shown in Fig. 1.

[0036] As shown in FIG. 7, in this embodiment, the first fixed shaft end face 4b is a surface of the fixed member 4 facing the other side along the axial direction, and the second fixed shaft end face 4c is a surface of the fixed member 4 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 face 4b. As shown in FIG. 8, the second fixed shaft end face 4c is a flat surface extending in the radial direction. The first fixed shaft end face 4b and the second fixed shaft end face 4c have asymmetric shapes. In other words, the shape of the fixed member 4 is not symmetrical on the front and back.

[0037] As shown in FIG. 8, in this embodiment, the contact portion 4d is a protrusion 4f that protrudes toward the main shaft end surface 6f. The protrusions 4f are provided at positions radially away from the shaft 2a and at intervals along the circumferential direction. The protrusions 4f are convex on the main shaft end surface 6f side and concave on the housing 2b side. In this embodiment, the protrusions 4f are provided by locally bending the fixed member 4 without changing the thickness of the entire fixed member 4, but the protrusions 4f may be provided by locally thickening the fixed member 4. As shown in FIG. 7, the protrusions 4f are formed in a truncated cone shape whose diameter decreases as it moves away from the first fixed shaft end surface 4b in the axial direction. The tip of the protrusions 4f is a flat surface extending in the radial direction. In this embodiment, the number of protrusions 4f is eight. The eight protrusions 4f are arranged on the same circumference centered on the central axis C.

[0038] As shown in FIG. 8, the separation portion 4e is provided from the shaft 2a to the protruding portion 4f. The separation portion 4e is separated from the main shaft end face 6f with the protruding portion 4f in contact with the main shaft end face 6f. In this embodiment, the separation portion 4e is a flat surface extending in the radial direction. The separation portion 4e is provided from the edge of the portion of the fixing insertion hole 4a that opens to the first fixed shaft end face 4b to the protruding portion 4f. The fixing member 4 may be manufactured by providing the protruding portion 4f on a metal plate such as a flat washer, or may be manufactured from a resin material.

[0039] This embodiment can also achieve the same effect as the first embodiment. In this embodiment, the first fixed shaft end face 4b is formed with a contact portion 4d and a separation portion 4e, and the second fixed shaft end face 4c is a plane extending in the radial direction. As a result, 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 each other can be changed simply by attaching the fixed member 4 to the shaft 2a so that the first fixed shaft end face 4b faces the main plate shaft end face 6f, or by attaching the fixed member 4 to the shaft 2a so that the second fixed shaft end face 4c faces the main plate shaft end face 6f. Therefore, the point where the electromagnetic vibration of the motor 2 propagates to the impeller 3 can be easily changed, and the natural frequency of the impeller 3 can be easily changed.

[0040] 8 shows the case where the fixed member 4 is attached to the shaft 2a so that the first fixed shaft end face 4b faces the main plate shaft end face 6f. When the fixed member 4 is attached to the shaft 2a so that the second fixed shaft end face 4c faces the main plate shaft end face 6f, the first fixed shaft end face 4b becomes the surface of the fixed member 4 facing one side along the axial direction, and the second fixed shaft end face 4c becomes the surface of the fixed member 4 facing the other side along the axial direction.

[0041] By increasing the radial dimension of the fixed member 4, it is possible to radially increase the minimum radial distance L from the central axis C of the shaft 2a to the point where the main plate shaft end surface 6f and the protruding portion 4f of the fixed member 4 come into contact. However, in order to enable the impeller 3 to rotate within the casing 5 while preventing the blower 1A from becoming larger, it is desirable to set the radial dimension of the fixed member 4 to a size that fits radially inward of the multiple blades 7.

[0042] Furthermore, the location where the main shaft end surface 6f and the protruding portion 4f of the fixed member 4 come into contact with each other becomes the fulcrum for rotation of the impeller 3. 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 shaft end surface 6f and the protruding portion 4f of the fixed member 4 come into contact with each other on their respective flat surfaces.

[0043] The fixed member 4 may have a configuration shown in FIG. 9. FIG. 9 is a perspective view showing a fixed member 4 according to a modified example of the second embodiment. The contact portion 4d is an annular flat surface. The contact portion 4d is provided at a position radially away from the shaft 2a shown in FIG. 8 and contacts the main shaft end surface 6f. The separation portion 4e is a stepped portion provided from the shaft 2a to the flat contact portion 4d and is increasingly separated from the main shaft end surface 6f as it moves from the outer side to the inner side in the radial direction. Even in this case, the same effects as those of the first and second embodiments can be achieved.

[0044] Embodiment 3 Next, a blower 1B according to a third embodiment will be described with reference to Figs. 10 and 11. In this embodiment, the configurations of the contact portion 6g and the separation portion 6h are different from those of the first embodiment. In the third embodiment, the same reference numerals are used for the parts that overlap with those of the first embodiment, and the description thereof will be omitted. Fig. 10 is a cross-sectional view of a blower 1B according to the third embodiment, and corresponds to the cross-sectional view taken along line II-II shown in Fig. 1. Fig. 11 is a perspective view of an impeller 3 according to the third embodiment.

[0045] As shown in Fig. 10, the radial center portion of the main plate shaft end surface 6f is formed in a stepped shape that is farther away from the housing 2b as it goes from the outer side to 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 in a concentric circle centered on the shaft 2a, and step surfaces 62 connecting adjacent flat surfaces 61. In this embodiment, the thickness of the main plate bottom wall portion 6a is made thicker than the thicknesses of the main plate side wall portion 6b and the main plate peripheral wall portion 6c, and the thickness of the main plate bottom wall portion 6a is partially changed to form the plurality of flat surfaces 61.

[0046] Each of the multiple flat surfaces 61 extends in the radial direction. The number of flat surfaces 61 may be increased or decreased as appropriate, but in this embodiment, the number is three. When distinguishing between the three flat surfaces 61, they are referred to as flat surface 61a, flat surface 61b, and flat surface 61c in order from the outer side to the inner side in the radial direction.

[0047] The step surface 62 extends in the axial direction. The step surface 62 connects the inner peripheral edge of the adjacent flat surface 61 to the outer peripheral edge of the flat surface 61. In this embodiment, the number of the step surfaces 62 is two. The number of the step surfaces 62 increases or decreases depending on the number of the flat surfaces 61. When distinguishing between the two step surfaces 62, they are referred to as step surface 62a and step surface 62b in order from the one closer to the housing 2b in the axial direction. The step surface 62a connects the inner peripheral edge of the flat surface 61a to the outer peripheral edge of the flat surface 61b. The step surface 62b connects the inner peripheral edge of the flat surface 61b to the outer peripheral edge of the flat surface 61c. The step surface 62b is located radially inward from the step surface 62a.

[0048] The more radially inward the flat surfaces 61 are, the further away they are from the housing 2b in the axial direction. In other words, when the central axis C of the shaft 2a is set as a normal line and a plane passing through the housing 2b is set as a reference plane S, the axial distance D between the flat surfaces 61 and the reference plane S is longer for flat surfaces 61 that are located radially inward. Note that FIG. 10 illustrates only the axial distance D between the flat surfaces 61a and the reference plane S.

[0049] In this embodiment, the fixing member 4 is in contact with the flat surface 61a, but may be in contact with the flat surface 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 flat surface 61a, or to bring the fixing member 4 into contact with the flat surface 61b.

[0050] When the fixing member 4 is brought into contact with the plane 61a, the plane 61a becomes the contact portion 6g, and the portion of the main shaft end surface 6f that is radially inward from the plane 61a becomes the separation portion 6h. On the other hand, when the fixing member 4 is brought into contact with the plane 61b, the plane 61b becomes the contact portion 6g, and the portion of the main shaft end surface 6f that is radially inward from the plane 61b becomes the separation portion 6h. In this embodiment, one of the multiple planes 61a, 61b becomes the contact portion 6g.

[0051] This embodiment can also achieve the same effect as the first embodiment. In this embodiment, the flat surfaces 61 provided on the main plate shaft end surface 6f are arranged so that the flat surfaces 61 located radially inward are more distant from the housing 2b in the axial direction, and one of the flat surfaces 61 serves as a contact portion 6g. This allows the radial dimension of the fixed member 4 to be changed to change 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 each other. Therefore, the point where the electromagnetic vibration of the motor 2 propagates to the impeller 3 can be easily changed, and the natural frequency of the impeller 3 can be easily changed.

[0052] Here, the effect of this embodiment will be further described with reference to Fig. 12 and Fig. 13. Fig. 12 is a graph showing the relationship between the axial deformation amount and the natural frequency of the impeller 3 when the radial dimension of the fixing member 4 is changed in the blower 1B according to the third embodiment, and is a graph based on a frequency response analysis. Fig. 13 is a graph showing the relationship between the circumferential deformation amount and the natural frequency of the impeller 3 when the radial dimension of the fixing member 4 is changed in the blower 1B according to the third embodiment, and is a graph based on a frequency response analysis. The frequency response analysis shown in Figs. 12 and 13 was performed under the condition that the radial dimension of the impeller 3 in the third embodiment is φ180 mm and the axial dimension of the impeller 3 is 100 mm.

[0053] 12 and 13, it can be seen that the impeller 3 has both an axial vibration mode in which it vibrates in the axial direction and a torsional vibration mode in which it vibrates in a twisted manner in the circumferential direction, and that the amplitude becomes large at the natural frequency. It can also be seen that the natural frequency of the impeller 3 can be changed by changing the radial dimension of the fixing member 4.

[0054] In this embodiment, by increasing the number of flat surfaces 61 that become the contact portions 6g shown in Fig. 10, the locations where the main plate 6 and the fixed member 4 come into contact can be finely adjusted. Even if the number of flat surfaces 61 that become the contact portions 6g is increased, the manufacturing cost can be reduced because of the simple structure. Furthermore, if a resin material is used as the material for the impeller 3, the impeller 3 and the flat surfaces 61 can be manufactured by integral molding, so that an increase in manufacturing costs due to an increase in the number of flat surfaces 61 can be reduced.

[0055] In addition, by increasing the radial dimension of the fixed member 4, it is possible to radially increase the minimum 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 each other. However, in order to enable the impeller 3 to rotate within the casing 5 while preventing the size of the blower 1B from increasing, it is desirable to set the radial dimension of the fixed member 4 and the radial dimension of each of the multiple flat surfaces 61 to a size that fits radially inward of the multiple blades 7.

[0056] The multiple planes 61 may have the configurations shown in Fig. 14 and Fig. 15. Fig. 14 is a cross-sectional view showing a blower 1C according to a first modification of the third embodiment, and corresponds to the cross-sectional view taken along line II-II shown in Fig. 1. Fig. 15 is a perspective view showing an impeller 3 according to the first modification of the third embodiment.

[0057] As shown in FIG. 14 and FIG. 15, the main plate shaft end surface 6f is provided with a plurality of cylindrical ribs 63 arranged in a concentric circle centered on the shaft 2a. As shown in FIG. 15, the portion of the main plate shaft end surface 6f other than the ribs 63 is a plane 64. The ribs 63 protrude toward the housing 2b beyond the plane 64. The tip of the rib 63 facing the housing 2b is a plane 61 extending in the radial direction. The number of ribs 63 may be increased or decreased as appropriate, but there are two in this modification. When distinguishing between the two ribs 63, they are referred to as rib 63a and rib 63b in order from the outside to the inside in the radial direction. The more radially inward the ribs 63 are located, the more distant they are from the housing 2b in the axial direction. The axial distance D between each rib 63 and the reference plane S is longer for the ribs 63 located radially inward among the plurality of ribs 63. Note that FIG. 14 illustrates only the axial distance D between the plane 61 of the rib 63a and the reference plane S.

[0058] In this modification, the fixing member 4 is in contact with the flat surface 61 of the rib 63a, but 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, or to bring the fixing member 4 into contact with the flat surface 61 of the rib 63b.

[0059] 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 multiple ribs 63a, 63b becomes the contact portion 6g. Even in this case, the same effects as those of the first and second embodiments described above can be achieved.

[0060] The flat surfaces 61 may have a configuration as shown in Fig. 16. Fig. 16 is a cross-sectional view showing a blower 1D according to Variation 2 of the third embodiment, and corresponds to the cross-sectional view taken along line II-II shown in Fig. 1. As shown in Fig. 16, the thickness of the main plate 6 as a whole may be kept constant, and the flat surfaces 61 may be provided by locally bending the main plate 6. The flat surfaces 61 located radially inward are more distant from the housing 2b in the axial direction.

[0061] Embodiment 4 Next, a blower 1E according to the fourth embodiment will be described with reference to Figs. 17 and 18. In this embodiment, the configurations of the contact portion 6g and the separation portion 6h are different from those of the first embodiment. In the fourth embodiment, the same reference numerals are used for the parts that overlap with those of the first embodiment, and the description thereof will be omitted. Fig. 17 is a cross-sectional view of a blower 1E according to the fourth embodiment, and corresponds to the cross-sectional view taken along the line II-II shown in Fig. 1. Fig. 18 is a perspective view of an impeller 3 according to the fourth embodiment.

[0062] As shown in FIG. 17 and FIG. 18, the main plate shaft end surface 6f is provided with a plurality of ribs 65 extending radially from the shaft 2a and protruding toward the housing 2b. As shown in FIG. 18, the plurality of ribs 65 are arranged at intervals from each other in the circumferential direction. The number of ribs 65 may be increased or decreased as appropriate, but in this embodiment, there are six. The surface of each rib 65 facing the housing 2b is provided with a plurality of rectangular flat surfaces 66 arranged along the radial direction and step surfaces 67 connecting adjacent flat surfaces 66. The shape of the surface of each rib 65 facing the housing 2b is a rotationally symmetric shape with the central axis C of the shaft 2a as the axis of symmetry. That is, the radial positions of the flat surfaces 66 of all the ribs 65 are the same.

[0063] The planes 66 extend in the radial direction. The number of planes 66 may be increased or decreased as appropriate, but in this embodiment, the number is three. When distinguishing between the three planes 66, they are referred to as plane 66a, plane 66b, and plane 66c in order from the outer side to the inner side in the radial direction.

[0064] The step surface 67 extends in the axial direction. The step surface 67 connects the inner edge of the adjacent flat surface 66 to the outer edge of the flat surface 66. In this embodiment, the number of step surfaces 67 is two. The number of step surfaces 67 increases or decreases depending on the number of flat surfaces 66. When distinguishing between the two step surfaces 67, they are referred to as step surface 67a and step surface 67b in order from the side closer to the housing 2b in the axial direction. The step surface 67a connects the inner edge of the flat surface 66a to the outer edge of the flat surface 66b. The step surface 67b connects the inner edge of the flat surface 66b to the outer edge of the flat surface 66c.

[0065] As shown in Fig. 17, the flat surfaces 66 are farther away from the housing 2b in the axial direction as they are radially more inward. The axial distance D between each flat surface 66 and the reference plane S is longer for each flat surface 66 that is radially more inward. Note that Fig. 17 only illustrates the axial distance D between the flat surface 66a and the reference plane S.

[0066] In this embodiment, the fixing member 4 is in contact with the flat surface 66a, but may be in contact with the flat surface 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 flat surface 66a, or to bring the fixing member 4 into contact with the flat surface 66b.

[0067] When the fixing member 4 is brought into contact with the plane 66a, the plane 66a becomes the contact portion 6g, and the portion of the main shaft end surface 6f that is radially inward from the plane 66a becomes the separation portion 6h. On the other hand, when the fixing member 4 is brought into contact with the plane 66b, the plane 66b becomes the contact portion 6g, and the portion of the main shaft end surface 6f that is radially inward from the plane 66b becomes the separation portion 6h. In this embodiment, one of the multiple planes 66a, 66b becomes the contact portion 6g.

[0068] This embodiment can also achieve the same effects as those of the first, second, and third embodiments. In this embodiment, as shown in FIG. 17, the flat surfaces 66 provided on the main plate shaft end surface 6f are arranged so that the flat surfaces 66 located radially inward are more distant from the housing 2b in the axial direction, and one of the flat surfaces 66 serves as a contact portion 6g. This allows the radial dimension of the fixed member 4 to be changed to change 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 each other. Therefore, the point where the electromagnetic vibration of the motor 2 propagates to the impeller 3 can be easily changed, and the natural frequency of the impeller 3 can be easily changed.

[0069] In this embodiment, the main plate shaft end surface 6f is provided with a plurality of ribs 65 extending radially from the shaft 2a and protruding toward the housing 2b, and among the plurality of flat surfaces 66 provided on the surface facing the housing 2b among the ribs 65, the more radially inward the flat surfaces 66 are, the more distant the flat surfaces 66 are from the housing 2b in the axial direction. This allows the contact points between the main plate 6 and the fixed member 4 to be changed not only in the radial direction but also in the circumferential direction. That is, by providing the plurality of ribs 65 extending radially from the shaft 2a and protruding toward the housing 2b on the main plate shaft end surface 6f, the main plate 6 and the fixed member 4 come into intermittent contact in the circumferential direction. Therefore, the natural frequency of the impeller 3 can be changed more finely.

[0070] In this embodiment, by increasing the number of ribs 65 or changing the width of the ribs 65, the points where the main plate 6 and the fixed member 4 contact each other in the circumferential direction can be finely adjusted, and the natural frequency of the impeller 3 can be changed more finely. Even if the number of ribs 65 is increased or the width of the ribs 65 is narrowed, the manufacturing cost can be reduced because of the simple structure. Furthermore, if a resin material is used as the material for the impeller 3, the impeller 3 and the ribs 65 can be manufactured by integral molding, and therefore an increase in manufacturing cost due to an increase in the number of ribs 65 or a narrower width of the ribs 65 can be reduced.

[0071] As shown in FIG. 19, the shape of the surface of each rib 65 facing the housing 2b may be rotationally asymmetric about the central axis C of the shaft 2a. FIG. 19 is a perspective view showing an impeller 3 according to a first modified example of the fourth embodiment. As shown in FIG. 19, the radial positions of the flat surfaces 66 of each rib 65 are different from each other. In the illustrated example, ribs 65 having flat surfaces 66 on the radial outer parts and ribs 65 having flat surfaces 66 on the radial central parts are alternately arranged in the circumferential direction. In the ribs 65 adjacent to each other in the circumferential direction, the flat surfaces 66 are provided offset in the radial direction. In this modified example, the contact points between the ribs 65 and the fixed member 4 can be individually changed for each rib 65, and the shortest radial distance L from the central axis C of the shaft 2a to the contact points between the main plate 6 and the fixed member 4 can be changed for each rib 65.

[0072] The main plate 6 may have a configuration as 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 portion 6b is provided with an opening 6i penetrating the main plate side wall portion 6b in the radial direction. The opening 6i is provided for air-cooling the motor 2. 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.

[0073] In this modification, the location where the main plate 6 and the fixed member 4 contact each other can be changed not only in the radial direction but also in the circumferential direction. Therefore, even if 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 can be changed, and the natural frequency of the impeller 3 can be changed so as to deviate from the resonance frequency. Therefore, resonance in the blower 1 can be avoided or reduced without using a vibration-damping material.

[0074] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0075] For example, the fans 1 to 1E according to the above-described embodiments may be used for ventilation purposes, air conditioning purposes, and other purposes.

[0076] In each of the above-described embodiments, the impeller 3 is applied to a multi-blade fan, but the impeller 3 may be applied to a fan other than a multi-blade fan. In other words, the impeller 3 is applicable to a general fan, whether it is a centrifugal fan or an axial fan.

[0077] In each of the above-described embodiments, the fans 1 to 1E are of a single suction type having one suction port 5d, but they may be of a double suction type having two suction ports 5d. [Explanation of symbols]

[0078] 1,1A,1B,1C,1D,1E,10 Blower, 2 motor, 2a shaft, 2b housing, 2c flange, 3 impeller, 4 fixing member, 4a fixing insertion hole, 4b first fixed shaft end face, 4c second fixed shaft end face, 4d,6g contact part, 4e,6h separation part, 4f protrusion part, 5 Casing, 5a Casing side wall, 5b Casing peripheral wall, 5c Air 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, 6i Opening, 7 Wing, 8 Reinforcing rings, 61, 61a, 61b, 61c, 64, 66, 66a, 66b, 66c flat surfaces, 62, 62a, 62b, 67, 67a, 67b stepped surfaces, 63, 63a, 63b, 65 ribs.

Claims

1. A motor having a shaft and a housing that accommodates a portion of the shaft; an impeller having a main plate attached to a portion of the shaft located outside the housing and rotating with the rotation of the shaft, and a plurality of blades provided at intervals along an outer circumferential edge of the main plate and extending in an axial direction of the shaft; a fixing member attached to the shaft between the main plate and the housing and in contact with 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 surface facing the fixed member, a contact portion provided at a position away from the shaft in a radial direction, which is a direction perpendicular to the axial direction, and in contact with the other of the main plate shaft end face and the fixed member, and a separation portion provided from the shaft to the contact portion and in a state where the contact portion is in contact with the other of the main plate shaft end face and the fixed member, and is separated from the other of the main plate shaft end face and the fixed member.

2. the contact portion is an annular flat surface provided at a position spaced apart from the shaft in the radial direction and in contact with the fixed member, The blower according to claim 1 , wherein the separating portion is a recess that is provided from the shaft to the flat surface and is separated from the fixed member in a state where the flat surface is in contact with the fixed member.

3. the contact portion and the separation portion are formed on one of a surface of the fixing member facing one side along the axial direction and a surface of the fixing member facing the other side along the axial direction, The blower according to claim 1 , wherein the other of the surface of the fixing member facing one side along the axial direction and the surface facing the other side along the axial direction is a flat surface.

4. The contact portion is a plurality of protruding portions provided at positions spaced apart from the shaft in the radial direction and spaced apart from each other along a circumferential direction which is a rotation direction of the shaft, and protruding toward the main plate shaft end surface, The blower according to claim 3, wherein the separation portion is a plane that is provided from the shaft to the protrusion and is separated from the main shaft end surface with the protrusion in contact with the main shaft end surface.

5. the contact portion is an annular flat surface provided at a position spaced apart from the shaft in the radial direction and in contact with the main plate shaft end surface, The blower according to claim 3, wherein the separation portion is a stepped portion that is provided from the shaft across the plane and that is spaced apart from the main plate shaft end surface in the axial direction as it moves from the radially outer side to the radially inner side.

6. The main plate shaft end surface is provided with a plurality of annular flat surfaces arranged concentrically around the shaft, the flat surfaces are spaced apart from the housing in the axial direction as the flat surfaces are positioned radially inward; The blower according to claim 1 , wherein one of the flat surfaces serves as the contact portion.

7. A plurality of ribs are provided on the end surface of the main shaft, the ribs extending radially from the shaft in the radial direction and protruding toward the housing, A surface of each of the ribs facing the housing is provided with a plurality of flat surfaces arranged along the radial direction, the flat surfaces are spaced apart from the housing in the axial direction as the flat surfaces are positioned radially inward; The blower according to claim 1 , wherein one of the flat surfaces serves as the contact portion.

8. The blower according to claim 7 , wherein the shape of a surface of each of the ribs facing the housing is rotationally asymmetric about a central axis of the shaft.

Images