JP6774595B2 - Impeller, blower, and method of manufacturing the impeller - Google Patents

Description

The present invention relates to an impeller, a blower, and a method for manufacturing the impeller.

Conventionally, an electric blower having an impeller that rotates at a high speed to generate a suction pressure is known (see, for example, Patent Document 1).

The impeller of the electric blower disclosed in Patent Document 1 includes a front shroud, a rear shroud, and a plurality of blades sandwiched between the front shroud and the rear shroud. A plurality of protrusions are formed on each blade. The plurality of protrusions are fitted into the opposing through holes of the front shroud and the rear shroud. The impeller is constructed by crimping the allowance from the through hole of the protrusion.

JP-A-2015-206272

In the impeller disclosed in Patent Document 1, the tip of the protrusion crushed for caulking fixing protrudes outward from the surfaces of the front shroud and the rear shroud. This protrusion becomes air resistance when the impeller rotates at high speed. For this reason, in the impeller disclosed in Patent Document 1, turbulence may occur when the impeller rotates at high speed, and the ventilation efficiency may decrease.

If the force for crushing the tip of the protrusion is increased in order to make the protrusion as small as possible, the blade, the front shroud, and the rear shroud may undergo plastic deformation. In particular, when a large force is applied to the blade in one direction, the blade is easily plastically deformed. When the blade undergoes plastic deformation, for example, rattling or air leakage occurs, which causes a problem.

Therefore, an object of the present invention is to provide an impeller capable of improving the ventilation efficiency. Another object of the present invention is to provide a blower device provided with such an impeller. Furthermore, an object of the present invention is to provide a method for manufacturing an impeller having high ventilation efficiency by reducing plastic deformation of the blade, the front shroud and the rear shroud as much as possible.

An exemplary impeller of the present invention is an impeller that rotates about a rotation axis, and is located on one side of a base plate that extends in a direction orthogonal to the axial direction and the base plate, and is spaced axially from the base plate. It has a shroud facing each other and a blade disposed between the base plate and the shroud, and at least one of the shroud and the base plate has a through hole through which the blade penetrates in the axial direction. The blade has a protrusion that is inserted into the through hole and the tip portion in the axial direction is caulked and fixed, and the radial inner side of the blade is located on one side in the circumferential direction with respect to the radial outer side of the blade. The hole has a first portion into which the root side of the protrusion is inserted and a second portion into which the tip end side of the protrusion is inserted and is wider in the circumferential direction than the first portion, and has one axial direction. In a plan view from at least one of the side and the other side, a gap is formed between the protrusion and the inner wall forming the second portion, and in a plan view from at least one of the axial direction and the other side, a gap is formed. The number of through holes where the area of the gap located on one side in the circumferential direction is larger than the area of the gap located on the other side in the circumferential direction is such that the area of the gap located on one side in the circumferential direction is located on the other side in the circumferential direction. The number of through holes is smaller than the area of the gap.

An exemplary impeller of the present invention is an impeller that rotates about a rotation axis, and is located on one side of a base plate that extends in a direction orthogonal to the axial direction and the base plate, and is spaced axially from the base plate. It has a shroud facing each other and a blade disposed between the base plate and the shroud, and at least one of the shroud and the base plate has a through hole through which the blade penetrates in the axial direction. The blade has a protrusion that is inserted into the through hole and the tip portion in the axial direction is caulked and fixed, and the radial inner side of the blade is located on one side in the circumferential direction with respect to the radial outer side of the blade. The hole has a first portion into which the root side of the protrusion is inserted and a second portion into which the tip end side of the protrusion is inserted and is wider in the circumferential direction than the first portion. The axial tip surface is flush with one axial end surface of the shroud or the other axial end surface of the base plate, and is laterally unidirectional in a plan view from at least one of the axial one side and the other side. The number of through holes where the area of the gap located on the other side in the circumferential direction is larger than the area of the gap located on the other side in the circumferential direction is the area of the gap in which the area of the gap located on one side in the circumferential direction is located on the other side in the circumferential direction. More than the number of smaller through holes.

An exemplary blower of the present invention comprises the impeller described above.

An exemplary method for manufacturing an impeller of the present invention is a method for manufacturing an impeller that rotates about a rotation axis, and is located on one side of a base plate that extends in a direction orthogonal to the axial direction of the impeller and the base plate. Prepare a shroud that faces the base plate at an axial distance, and a blade that is arranged between the base plate and the shroud and whose inner side in the radial direction is located on one side in the circumferential direction with respect to the outer side in the radial direction. A first step of forming an axially extending protrusion on at least one of the blades on one side and the other side in the axial direction, and at least one of the shroud and the base plate, the root side of the protrusion is A through hole is formed having a first portion to be inserted and a second portion in which the tip end side of the protrusion is inserted and the width in the circumferential direction is wider than that of the first portion, and one side and the other side in the axial direction are formed. In a plan view from at least one of the above, the number of the through holes whose area on one side in the circumferential direction is larger than the area of the gap located on the other side in the circumferential direction is the number of the gaps located on one side in the circumferential direction. A third step in which the area of the blade is larger than the number of through holes smaller than the area of the gap located on the other side in the circumferential direction, and the protrusion is inserted into the through hole to form the blade with the base plate and the shroud. It has a fourth step of sandwiching the shroud or the base plate and a fifth step of crimping the blade.

According to an exemplary invention, it is possible to provide an impeller capable of improving the ventilation efficiency. Further, according to an exemplary invention, it is possible to provide a blower device including such an impeller. Further, according to an exemplary invention, it is possible to provide a method for manufacturing an impeller having high ventilation efficiency while reducing plastic deformation of the blade as much as possible.

FIG. 1 is a schematic perspective view of a blower device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the blower according to the embodiment of the present invention. FIG. 3 is a schematic perspective view of the impeller according to the embodiment of the present invention. FIG. 4 is a schematic perspective view of a base plate included in the impeller according to the embodiment of the present invention. FIG. 5 is a schematic perspective view of a shroud included in the impeller according to the embodiment of the present invention. FIG. 6 is a schematic perspective view of a plurality of blades included in the impeller according to the embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a through hole provided in the base plate included in the impeller according to the embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of a through hole provided in the shroud provided in the impeller according to the embodiment of the present invention. FIG. 9 is a schematic view showing the relationship between through holes and protrusions in the base plate provided by the impeller according to the embodiment of the present invention. FIG. 10 is a schematic view showing the relationship between through holes and protrusions in the shroud provided by the impeller according to the embodiment of the present invention. FIG. 11 is a schematic enlarged view showing a part of the configuration when the impeller according to the embodiment of the present invention is viewed in a plan view from one side in the axial direction. FIG. 12 is a schematic enlarged view showing a part of the configuration when the impeller according to the embodiment of the present invention is viewed in a plan view from the other side in the axial direction. FIG. 13 is a schematic side view of the impeller before caulking formed in the method for manufacturing the impeller according to the embodiment of the present invention. FIG. 14 is a schematic view showing the relationship between the through hole and the protrusion in the impeller before caulking. FIG. 15 is a schematic front view showing a caulking device used in the method for manufacturing an impeller according to an embodiment of the present invention. FIG. 16 is a schematic cross-sectional view showing a first modification of a through hole provided in a shroud provided in an impeller according to an embodiment of the present invention. FIG. 17 is a schematic cross-sectional view showing a 21st modification of a through hole provided in a shroud provided in an impeller according to an embodiment of the present invention. FIG. 18 is a schematic cross-sectional view showing a third modification of the through hole provided in the shroud provided in the impeller according to the embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In the present specification, the extending direction of the central axis A of the blower shown in FIG. 1 is simply referred to as "axial direction", and the radial and circumferential directions about the central axis A of the blower are simply "diameter" and "diameter". We will call it "circumferential direction". Similarly, with respect to the impeller, the directions that coincide with the axial direction, the radial direction, and the circumferential direction of the blower in the state of being incorporated in the blower are simply referred to as "axial direction", "diameter direction", and "circumferential direction". I will decide. In the present specification, the direction parallel to the central axis A when the blower is arranged in the direction shown in FIG. 2 is defined as the vertical direction. The vertical direction is just a name used for explanation, and does not limit the actual positional relationship or direction. Further, in the present specification, flushing also includes a state in which flushing is not necessarily completely flushing.
<1. Blower configuration>

The blower of an exemplary embodiment of the present invention will be described. FIG. 1 is a schematic perspective view of a blower device 1 according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the blower 1 according to the embodiment of the present invention. As shown in FIGS. 1 and 2, the blower 1 includes a motor 2, an impeller 3, an impeller cover 4, and a control board 5.

The motor 2 has a tubular motor cover 20 extending in the axial direction. The motor cover 20 covers the rotor 21 and the stator 22. The cylindrical rotor 21 includes a magnet. The rotor 21 is fixed to the shaft 23. The shaft 23 is a columnar member extending along the central axis A. The rotor 21 is arranged radially outward of the shaft 23 and surrounds the shaft 23 around an axis. The shaft 23 is rotatably supported around the central axis A by the upper bearing 24a and the lower bearing 24b. The upper bearing 24a is arranged above the rotor 21. The lower bearing 24b is arranged below the rotor 21.

The annular stator 22 includes a stator core made of a laminated steel plate and a coil wound around the stator core via an insulating member. The stator 22 is an armature of the motor 2. The stator 22 is arranged radially outward of the rotor 21 and surrounds the rotor 21. The stator 22 is fixed to the motor cover 20.

The motor 20 has a sensor substrate 25 arranged between the rotor 21 and the lower bearing 24b. At least three rotation sensors 25a are mounted on the sensor board 25. The rotation sensor 25a is, for example, a Hall element. In detail, the rotation sensor 25a faces the sensor magnet that rotates with the rotation of the rotor 21. The rotation sensor 25a can detect the rotation position of the rotor 21.

The impeller 3 is fixed to the upper end of the shaft 23. For this purpose, the impeller 3 is rotated together with the shaft 23 by the drive of the motor 20. That is, the impeller 3 rotates about the rotation axis. In this embodiment, the rotation axis of the impeller is the central axis A. The detailed configuration of the impeller 3 will be described later.

The impeller cover 4 includes an upper wall portion 40 that covers the impeller 3 from above. The upper wall portion 40 is annular in a plan view from the axial direction. A protruding portion 40a projecting upward is provided at the central portion of the upper wall portion 40. The protrusion 40a has a cylindrical shape extending in the axial direction. That is, the upper wall portion 40 has a circular cover opening 40b in a plan view from the axial direction by having the protruding portion 40a. In a plan view from the axial direction, the center of the cover opening 40b coincides with the central axis A. By providing the cover opening 40b, a part of the impeller 3 is exposed to the outside of the blower 1 in a plan view from the upper side in the axial direction. A plurality of reinforcing ribs 40c extending in the radial direction from the protruding portion 40a to the outer peripheral end are provided on the outer surface of the upper wall portion 40. The plurality of reinforcing ribs 40c are arranged at equal intervals in the circumferential direction.

The impeller cover 4 has a side wall portion 41 that covers the impeller 3 from the side. The side wall portion 41 has a cylindrical shape extending downward in the axial direction from the outer peripheral edge of the upper wall portion 40. In the present embodiment, the side wall portion 41 is the same member as the upper wall portion 40. In a plan view from the axial direction, the center of the side wall portion 41 coincides with the central axis A. The diameter of the side wall portion 41 is the same as the diameter of the motor cover 20. The outer peripheral surface of the side wall portion 40 and the outer peripheral surface of the motor cover 20 are flush with each other. In the present embodiment, in detail, the outer peripheral side diameter of the upper end portion of the motor cover 20 is provided to be substantially the same as the inner peripheral side diameter of the lower end portion of the side wall portion 41. In detail, the former is slightly smaller than the latter. As a result, the side wall portion 41 is covered with the motor cover 20.

The control board 5 is arranged on the lower side in the axial direction of the motor 2. The control board 5 is supported by, for example, a motor 2. An electric field capacitor 50 is mounted on the lower surface of the control board 5. The control board 5 is electrically connected to a lead wire forming a coil included in the stator 22 and a sensor board 25 to control the motor 2.

In the blower 1, the impeller 3 rotates at high speed by driving the motor 2. The impeller 3 rotates at a speed of, for example, about 70,000 rpm. Due to the high-speed rotation of the impeller 3, air is drawn into the impeller 3 from the cover opening 40b. The air drawn into the impeller 3 is discharged radially outward through the air flow path in the impeller 3. The air discharged from the impeller 3 is guided to the inside of the motor 2 along the flow path in the impeller cover 4, and then discharged to the outside of the motor 2.
<2. Impeller configuration>

Impeller 3 of an exemplary embodiment of the present invention will be described. FIG. 3 is a schematic perspective view of the impeller 3 according to the embodiment of the present invention. As shown in FIG. 3, the impeller 3 includes a base plate 30, a shroud 31, and a blade 32. In this embodiment, as an example, the base plate 30, the shroud 31, and the blade 32 are made of the same metal material. The base plate 30, shroud 31, and blade 32 are made of, for example, an aluminum alloy. However, the base plate 30, the shroud 31, and the blade 32 may be formed of a material other than the aluminum alloy, or may be formed of different materials.

FIG. 4 is a schematic perspective view of the base plate 30 included in the impeller 3 according to the embodiment of the present invention. The base plate 30 extends in a direction orthogonal to the axial direction. Specifically, the base plate 30 has a disc shape. The base plate 30 has a shaft opening 301 that penetrates in the central portion in the axial direction. The upper end of the shaft 23 is inserted into the shaft opening 301. The outer edge portion of the shaft opening 301 has an arc portion 301a and a straight portion 301b in a plan view from the axial direction (see FIG. 12 described later). This shape corresponds to the upper end portion of the shaft 23, and enables the impeller 3 to be non-rotatably attached to the shaft 23.

At least one of the shroud 31 and the base plate 30 has through holes 302 and 313 that penetrate in the axial direction. In this embodiment, the base plate 30 has a through hole 302 that penetrates in the axial direction. Specifically, the base plate 3 has a plurality of through holes 302. The plurality of through holes 302 are regularly arranged around the shaft opening 301. The base plate 30 is arranged inward in the radial direction with respect to the plurality of through holes 302, and also has a plurality of auxiliary through holes 303 surrounding the periphery of the shaft opening 301. Details of the shapes and arrangements of the plurality of through holes 302 and the auxiliary through holes 303 will be described later.

FIG. 5 is a schematic perspective view of the shroud 31 included in the impeller 3 according to the embodiment of the present invention. The shroud 31 is located on one side of the base plate 30 and faces the base plate 30 at an axial distance. In this embodiment, the shroud 31 is located above the base plate 30. The shroud 31 is formed in a cylindrical shape that is squeezed upward in the axial direction. More specifically, the shroud 31 has a substantially truncated cone-shaped tip-squeezed portion 311 and a flat plate portion 312 located radially outward from the tip-squeezed portion 311. The flat plate portion 312 is annular in a plan view from the upper side in the axial direction. The upper end of the pre-squeezed portion 311 has a large opening. The opening 311a is an intake port of the impeller 3. The diameter of the shroud 31 is the same as the diameter of the base plate 30. In a plan view from the axial direction, the outer peripheral edge of the shroud 31 and the outer peripheral edge of the base plate 30 overlap each other.

The shroud 31 has a through hole 313 that penetrates in the axial direction. More specifically, the shroud 31 has a plurality of through holes 313. The plurality of through holes 313 are regularly arranged around the opening 311a. The plurality of through holes 313 are formed not only in the flat plate portion 312 but also in the pre-squeezed portion 311. Details of the shape and arrangement of the plurality of through holes 313 will be described later.

As shown in FIG. 3, the blade 32 is arranged between the base plate 30 and the shroud 31. Specifically, the impeller 3 has a plurality of blades 32. FIG. 6 is a schematic perspective view of a plurality of blades 32 included in the impeller 3 according to the embodiment of the present invention. The blade 32 is a plate-shaped member extending from the inside to the outside in the radial direction of the impeller 3. The blade 32 is curved in detail. The blade 32 is arranged upright along the axial direction. The plurality of blades 32 are arranged at equal intervals in the circumferential direction.

In the present embodiment, the blade 32 includes two types of blades 32a and 32b. The number of types of blades 32 is not limited to the number of the present embodiment, and may be one type or three or more types. The two types of blades 32a and 32b are of the same type and are arranged at equal intervals along the circumferential direction. In the present embodiment, the number of the first blade 32a and the second blade 32b is seven. The total number of blades 32 included in the impeller 3 is 14. The numbers of the blades 32a and 32b are merely examples and may be changed as appropriate. In some cases, the numbers of the first blade 32a and the second blade 32b may be different.

The first blade 32a and the second blade 32b extend with a curvature in a plan view from the axial direction. The first blade 32a and the second blade 32b are curved in the radial direction inward with respect to the radial outward direction when the impeller 3 is rotated in the counterclockwise direction in a plan view from the upper side in the axial direction. The shape. Both one ends of the first blade 32a and the second blade 32b are located on the outer peripheral edge of the base plate 30. The other ends of the first blade 32a and the second plate 32b are located radially inside the outer peripheral edge of the base plate 30. However, the other end of the first blade 32a is located radially outward of the other end of the second blade 32b. That is, the first blade 32a has a shorter radial length than the second blade 32b.

The blade 32 has protrusions 321 projecting on one side (upper side) and the other side (lower side) in the axial direction. The first blade 32a is formed by bending a substantially rectangular plate-shaped member extending in the radial direction in the circumferential direction. The first blade 32a has a protrusion 321 projecting upward in the axial direction at the radial inner end and the radial outer end. The first blade 32a has a protrusion 321 projecting downward in the axial direction at the radial inner end and the radial outer end. The first blade 32a has a total of four protrusions 321. The radial position of the protrusion 321 protruding upward in the axial direction and the protrusion 321 protruding downward in the axial direction are the same, and both have the same shape. In the present embodiment, the protrusion 321 has a rectangular plate shape as an example.

The second blade 32b includes a substantially rectangular plate-shaped rectangular portion 32aa extending in the radial direction and a plate-shaped wide portion 32ab having a portion wider in the axial direction than the rectangular portion 322aa. The wide portion 32ab is located radially inside the rectangular portion 32aa. The wide portion 32ab is inclined in accordance with the inclination of the tip squeezing portion 311 to widen the width in the axial direction. In a plan view from the upper side in the axial direction of the impeller 3, a part of the wide portion 32ab can be seen through the opening 311a.

The rectangular portion 32aa is curved in the same manner as the first blade 32a. Similar to the first blade 32a, the rectangular portion 32aa is provided with a protrusion 321 projecting upward in the axial direction and a protrusion 321 projecting downward in the axial direction. The radial position of the protrusion 321 provided on the rectangular portion 32aa is the same as that of the first blade portion 32a. That is, the protrusion 321 provided on the rectangular portion 32aa and the protrusion 321 provided on the first blade portion 32a are aligned on the same circle. The wide portion 32ab is connected to the rectangular portion 322a while being curved in the circumferential direction. The wide portion 32ab has an auxiliary protrusion 322 that projects downward in the axial direction. The second blade 32b has a total of four protrusions 321 and one auxiliary protrusion 322.

Each protrusion 321 projecting downward in the axial direction of the blade 32 is inserted into each through hole 302 of the base plate 30. That is, each of the plurality of through holes 302 is provided at a position of the base plate 30 facing each protrusion 321 projecting downward in the axial direction of the blade 32. As shown in FIG. 4, the base plate 30 has two through-hole groups in which a plurality of through-holes 302 are arranged at equal intervals on the same radial position. The two through-hole groups have different radial positions formed in the base plate 30. In this embodiment, each of the two through-hole groups has 14 through-holes 302.

Each of the plurality of auxiliary through holes 303 is provided at a position of the base plate 30 facing each auxiliary protrusion 32 of the second blade 32b. The plurality of auxiliary through holes 303 are arranged inward in the radial direction from the two through hole groups, and are arranged at equal intervals on the same radial position. In the present embodiment, the number of the plurality of auxiliary through holes 303 is seven.

Each protrusion 321 protruding upward in the axial direction of the blade 32 is inserted into each through hole 313 of the shroud 31. That is, each of the plurality of through holes 313 is provided at a position of the shroud 31 facing each protrusion 321 protruding upward in the axial direction of the blade 32. As shown in FIG. 5, the shroud 31 has two through-hole groups in which a plurality of through-holes 313 are arranged at equal intervals on the same radial position. The two through-hole groups differ in the radial position formed in the shroud 31. In this embodiment, each of the two through-hole groups has 14 through-holes 313.

The protrusions 321 inserted into the through holes 302 and 313 are crimped and fixed by crushing the tip in the axial direction. That is, the blade 32 has a protrusion 321 that is inserted into the through holes 302 and 313 and whose axial tip is caulked and fixed. The axial tip of the protrusion 321 protruding downward in the axial direction is the lower end of the protrusion 321 in the axial direction. The axial tip of the protrusion 321 projecting upward in the axial direction is the axial upper end of the protrusion 321.

In the present embodiment, the axial tip portions of the auxiliary protrusions 322 inserted into the plurality of auxiliary through holes 303 are not caulked and fixed. However, this is only an example, and a plurality of auxiliary through holes 303 may also be caulked and fixed.

The through hole 302 provided in the base plate 30 has a substantially rectangular shape in a plan view from the axial direction. In the present embodiment, the through hole 302 is slightly curved in the circumferential direction according to the shape of the protrusion 321. The longitudinal direction of the substantially rectangular through hole 302 is inclined with respect to the circumferential direction and the radial direction in a plan view from the axial direction.

FIG. 7 is a schematic cross-sectional view of a through hole 302 provided in the base plate 30 included in the impeller 3 according to the embodiment of the present invention. FIG. 7 is a cross-sectional view of the base plate 30 cut along the circumferential direction. The through hole 302 has a first portion 302a and a second portion 302b. The through hole 302 has a first portion 302a provided on the upper side in the axial direction. The root side of the protrusion 321 is inserted into the first portion 302a. The through hole 302 has a second portion 302b provided on the lower side in the axial direction. The second portion 302b is wider in the circumferential direction than the first portion 302a by inserting the tip end side of the protrusion 321.

The first portion 302a is provided slightly wider than the protrusion 321 in the circumferential direction and the radial direction. The first portion 302a has an inner wall 3021 extending axially downward from the upper end of the base plate 30. The inner wall 3021 extends to, for example, an intermediate position in the axial thickness of the base plate 30. The second portion 302b has an inclined surface 3022 extending from the lower end of the inner wall 3021 to the lower end of the base plate 30. The inclined surface 3022 is inclined in a direction in which the width of the hole is wider than that of the first portion 302a. The inclination angle of the inclined surface 3022 is not particularly limited and may be any value. The inclination angle is an angle with respect to the lower end surface 30a of the base plate 30. In the present embodiment, the magnitude of the inclination angle of the inclined surfaces 3022 facing in the circumferential direction is the same. That is, the second portion 302b has a cross-sectional shape symmetrical in the circumferential direction.

In the present embodiment, the second portion 302b is formed wider than the first portion 302a in the radial direction as well as in the circumferential direction. Further, in the present embodiment, the auxiliary through hole 303 has a shape different from that of the through hole 302 because the auxiliary protrusion 322 is not crimped and fixed. The auxiliary through hole 303 has, for example, the same shape as the first portion 302a over the entire axial direction.

The through hole 313 provided in the shroud 31 has a substantially rectangular shape in a plan view from the axial direction. In the present embodiment, the through hole 313 is slightly curved in the circumferential direction according to the shape of the protrusion 321. The longitudinal direction of the substantially rectangular through hole 313 is inclined with respect to the circumferential direction and the radial direction in a plan view from the axial direction. In the present embodiment, the through hole 313 provided in the shroud 31 overlaps with the through hole 302 provided in the base plate in a plan view from the axial direction.

FIG. 8 is a schematic cross-sectional view of a through hole 313 provided in the shroud 31 included in the impeller 3 according to the embodiment of the present invention. FIG. 8 is a cross-sectional view of the shroud 31 cut along the circumferential direction. The through hole 313 has a first portion 313a provided on the lower side in the axial direction. The root side of the protrusion 321 is inserted into the first portion 313a. The through hole 313 has a second portion 313b provided on the upper side in the axial direction. The width of the second portion 313b in the circumferential direction is wider than that of the first portion 313a by inserting the tip end side of the protrusion 321.

The first portion 313a is provided slightly wider than the protrusion 321 in the circumferential direction and the radial direction. The first portion 313a has an inner wall 3131 extending axially upward from the lower end of the shroud 31. The inner wall 3131 extends, for example, to an intermediate position in the axial thickness of the shroud 31. The second portion 313b has an inclined surface 3132 extending from the upper end of the inner wall 3131 to the upper end of the shroud 31. The inclined surface 3132 is inclined in a direction in which the width of the hole is wider than that of the first portion 313a. The inclination angle of the inclined surface is not particularly limited and may be any value. The inclination angle is an angle with respect to the upper end surface 31a of the shroud 31. In the present embodiment, the magnitude of the inclination angle of the inclined surfaces 3132 facing in the circumferential direction is the same. That is, the second portion 313b has a cross-sectional shape symmetrical in the circumferential direction.

In the present embodiment, the second portion 313b is formed wider than the first portion 313a in the radial direction as well as in the circumferential direction. Further, in the present embodiment, the through hole 313 provided in the shroud 31 has a configuration in which the through hole 302 provided in the base plate 30 is turned upside down. However, this is only an example, and the through hole 313 provided in the shroud 313 may have a different configuration from the through hole 302 provided in the base plate 30.

FIG. 9 is a schematic view showing the relationship between the through hole 302 and the protrusion 321 in the base plate 30 included in the impeller 3 according to the embodiment of the present invention. FIG. 9 is a cross-sectional view of the base plate 30 and the protrusion 321 cut along the circumferential direction. The axial tip surface of the protrusion 321 is flush with the axial one-sided end surface of the shroud 31 or the axial other-side end surface of the base plate 30. This makes it possible to reduce the air resistance on the surface of the impeller 3 and reduce the occurrence of turbulence. Therefore, the ventilation efficiency of the impeller 3 can be improved. In the present embodiment, the axial tip surface 321a of the protrusion 321 is flush with the axial opposite end surface (axial lower end surface) 30a of the base plate 30. The axial tip portion of the protrusion 321 is crushed for caulking and fixing, and expands in the in-plane direction parallel to the axial lower end surface 30a. The second portion 302b is formed wider than the protrusion 321. The crushed portion of the protrusion 321 is housed in the second portion 302b. As a result, the axial tip surface 321a becomes flush with the axial lower end surface 30a. The flush surface includes a state in which the axial tip surface 321a is slightly above or below the axial lower end surface 30a.

FIG. 10 is a schematic view showing the relationship between the through hole 313 and the protrusion 321 in the shroud 31 included in the impeller 3 according to the embodiment of the present invention. FIG. 10 is a cross-sectional view of the shroud 31 and the protrusion 321 cut along the circumferential direction. The axial tip surface 321a of the protrusion 321 is flush with the axial one-side end surface (axial upper end surface) 31a of the shroud 31. The reason why the axial tip surface 321a is flush with the axial upper end surface 31a is the same as in the case of the base plate 30. Further, the flushing referred to here includes a state in which the axial tip surface 321a is slightly above or below the axial upper end surface 31a.

In the impeller 3 of the present embodiment, the protrusion 321 of the blade 32 is flush with the end surface on both the upper end surface 31a and the lower end surface 30a in the axial direction. Therefore, the impeller 3 of the present embodiment can reduce the air resistance on the surface of the impeller 3 and reduce the occurrence of turbulence. The impeller 3 of the present embodiment can improve the ventilation efficiency.

FIG. 11 is a schematic enlarged view showing a part of the configuration when the impeller 3 according to the embodiment of the present invention is viewed in a plan view from one side in the axial direction. FIG. 12 is a schematic enlarged view showing a part of the configuration when the impeller 3 according to the embodiment of the present invention is viewed in a plan view from the other side in the axial direction. A part of the second portion 302b and 313b is exposed in a plan view from at least one side in the axial direction and the other side. In the present embodiment, a part of the second portion 313b is exposed in a plan view from one side (upper side) in the axial direction. A part of the second portion 302b is exposed in a plan view from the other side (lower side) in the axial direction.

The second portion 302b, 313b is formed larger than the size required to accommodate the axial tip of the protrusion 321 crushed for caulking fixation. In a part of the second portion 302b and 313b, a space is created in which the crushed portion of the protrusion 321 does not enter. As a result, a part of the second portion 302b and 313b is exposed. According to the impeller 3 of the present embodiment, since the protrusion 321 of the protrusion 321 can be suppressed from the surface of the impeller 3, the air resistance can be reduced and the occurrence of turbulent flow can be reduced. According to the impeller 3 of the present embodiment, the ventilation efficiency can be improved.

In a plan view from at least one side and the other side in the axial direction, the second portions 302b and 313b have a first exposed portion and a second exposed portion. In the present embodiment, as shown in FIG. 11, the second portion 313b has a first exposed portion 33a and a second exposed portion 33b in a plan view from one side in the axial direction. The first exposed portion 33a is located on one side in the circumferential direction. The second exposed portion 33b is located on the other side in the circumferential direction. The first exposed portion 33a and the second exposed portion 33b are gaps formed between the protrusion 321 and the inner wall forming the second portion 313b in the circumferential direction. The first exposed portion 33a and the second exposed portion 33b are located on opposite sides in the circumferential direction with the protrusion 321 interposed therebetween. The area of the first exposed portion 33a and the area of the second exposed portion 33b are different from each other in a plan view from one side in the axial direction. Such a shape is formed by performing a caulking step using a roller that swivels the axial tip portion of the protrusion 321 in the circumferential direction. By performing the caulking step using the roller 63, the impeller 3 with as little plastic deformation as possible can be configured. The caulking process using rollers will be described later.

As shown in FIG. 12, the shape in which the area of the first exposed portion 33a and the area of the second exposed portion 33b are different is also recognized in a plan view from the other side in the axial direction. This point will be described later.

As shown in FIGS. 3 and 11, the impeller 3 has a plurality of through holes 313 into which the protrusions 321 are inserted. In a plan view from at least one of one side and the other side in the axial direction, the number of through holes 313 in which the area of the first exposed portion 33a is larger than the area of the second exposed portion 33b is the area of the first exposed portion 33a. Is larger than the number of through holes 313, which is smaller than the area of the second exposed portion 33b. In the present embodiment, the number of through holes 313 in which the area of the first exposed portion 33a is larger than the area of the second exposed portion 33b in the plan view from one side in the axial direction is the area of the first exposed portion 33a. Is larger than the number of through holes 313, which is smaller than the area of the second exposed portion 33b. Further, in a plan view from at least one of one side and the other side in the axial direction, the total area of the first exposed portion 33a and the total area of the second exposed portion 33b are different. In the present embodiment, the total area of the first exposed portion 33a is larger than the total area of the second exposed portion 33b. In the present embodiment, the total area of the first exposed portion 33a and the total area of the second exposed portion 33b are different in a plan view from one side in the axial direction. In the present embodiment, the total area of the first exposed portion 33a is larger than the total area of the second exposed portion 33b. These shapes are formed by performing a caulking step using a roller that rotates the axial tip portion of the protrusion 321 in the circumferential direction. By performing the caulking step using the roller 63, the impeller 3 with as little plastic deformation as possible can be configured. The caulking process using rollers will be described later. As shown in FIG. 12, these shapes are also recognized in a plan view from the other side in the axial direction. A description of this point will be described later.
<3. Impeller manufacturing method>

A method for producing the impeller 3 according to an exemplary embodiment of the present invention will be described. The method for manufacturing the impeller 3 includes a first step of preparing the base plate 30, the shroud 31, and the blade 32. The base plate 30 extends in a direction orthogonal to the axial direction of the impeller 3. The shroud 31 is located on one side of the base plate 30 and faces the base plate 30 with a gap in the axial direction. The blade 32 is arranged between the base plate 30 and the shroud 31. For the preparation of the base plate 30, the shroud 31, and the blade 32, press working using a die is used. These members 30 to 32 may be prepared from any of them, and the order thereof is not particularly limited. These members 30 to 32 may be prepared at the same time. As the blade 32, a plurality of types of the first blade 32a and the second blade 32b are prepared.

The method for manufacturing the impeller 3 includes a second step of forming a protrusion 321 extending in the axial direction on at least one of the axially one side (upper side) and the other side (lower side) of the blade 32. In this embodiment, protrusions 321 are formed on both the upper side and the lower side in the axial direction. That is, in the second step, protrusions 321 are formed on both one side and the other side in the axial direction. Pressing using a die is used to form the protrusions 321. The step of forming the protrusion 321 may be performed at the same time as the preparation of the blade 32 in the first step. In this embodiment, the auxiliary protrusion 322 is formed at the same time as the protrusion 321 is formed. Since the auxiliary protrusion 322 is not crimped and fixed, the protrusion height in the axial direction is formed to be smaller than that of the protrusion 321.

The method for manufacturing the impeller 3 includes a third step of forming a through hole in at least one of the shroud 31 and the base plate 30. In this embodiment, through holes 302 and 313 are formed in both the shroud 31 and the base plate 30. That is, both the shroud 31 and the base plate 30 have through holes 302 and 313. The through holes 302 and 313 have a first portion 302a, 313a and a second portion 302b, 313b. Therefore, the through holes 302 and 313 are formed in the order of drilling by press, chamfering, and chamfering. The formation of the through hole may be performed first from either the shroud 31 or the base plate 30. The formation of the through hole may be performed simultaneously in the shroud 31 and the base plate 30. The third step may be performed at the same time as at least one of the first step and the second step.

The method for manufacturing the impeller 3 includes a fourth step of inserting the protrusion 321 into the through holes 302 and 313 and sandwiching the blade 32 between the base plate 30 and the shroud 31. In this embodiment, both the base plate 30 and the shroud 31 insert the protrusions 321 into the through holes 302 and 313. By the fourth step, the impeller before caulking is formed.

FIG. 13 is a schematic side view of the impeller 3'before caulking, which is formed in the method for manufacturing the impeller 3 according to the embodiment of the present invention. As shown in FIG. 13, before caulking, the protrusion 321 protrudes from the axial lower end surface 30a of the base plate 30. Further, the protrusion 321 protrudes from the axial upper end surface 31a of the shroud 31. The tip of the auxiliary protrusion 322 is flush with the axial lower end surface 30a of the base plate 30.

FIG. 14 is a schematic view showing the relationship between the through holes 302 and 313 and the protrusions 321 in the impeller 3'before caulking. The volume of the space S1 composed of the axial lower end surface 30a of the base plate 30, the inclined surface 3022, and the side wall of the protrusion 322 is formed to be slightly larger than the volume of the portion of the protrusion 321 protruding from the axial lower end surface 30a. .. The volume of the space S2 formed by the axial upper end surface 31a of the shroud 31, the inclined surface 3132, and the side wall of the protrusion 322 is formed to be slightly larger than the volume of the protrusion 321 protruding from the axial one-side end surface 31a. Therefore, when the axial tip portion of the protrusion 321 is crushed by the caulking step performed later, the protrusion 322 is accommodated in the through holes 302 and 313.

The method for manufacturing the impeller 3 includes a fifth step of crimping the shroud 31 or the base plate 30 and the blade 32. In the present embodiment, the method for manufacturing the impeller 3 includes a fifth step of crimping the shroud 31 and the blade 32. The fifth step is a caulking step. FIG. 15 is a schematic front view showing a caulking device 6 used in the method for manufacturing the impeller 3 according to the embodiment of the present invention. The caulking device 6 has a pedestal 60 fixed to a device main body (not shown). The caulking device 6 has a jig 61 fixed to the pedestal 60 and on which the impeller 3'before caulking is placed. The caulking device 6 has a swivel portion 62 that rotates about an axis that substantially coincides with the central axis of the impeller 3'before caulking mounted on the jig 61. In the present embodiment, as an example, the rotation direction of the swivel portion 62 is a clockwise direction in a plan view from above. In the caulking step, a plurality of rollers 63 arranged at equal intervals in the circumferential direction are used. Specifically, a plurality of free-rotating rollers 63 are attached to the lower surface of the swivel portion 62. The plurality of rollers 63 are arranged at equal intervals in the circumferential direction with reference to the rotation axis of the swivel portion 62. In this embodiment, the number of rollers 63 is two, and the two rollers 63 are arranged at 180 ° intervals. The swivel portion 62 is movable in the vertical direction.

When crimping the shroud 31 and the blade 32, the impeller 3'before crimping is placed on the jig 61. The impeller 3'before caulking is placed on the jig 61 with the shroud 31 facing up. The jig 61 is formed with a plurality of holes for fitting the protrusions 321 protruding downward from the base plate 30. The swivel portion 62 is lowered downward with the impeller 3'before caulking mounted on the jig 61. The swivel portion 62 is lowered until the roller 63 comes into contact with the impeller 3'before caulking. In this state, the swivel portion 62 is swiveled, and the roller 62 is also swiveled. The roller 62 turns while rolling on the shroud 31. As a result, the axial tip portion of the protrusion 321 is crushed, and the shroud 31 and the blade 32 are crimped.

In the present embodiment, a through hole 313 is also formed in a part of the pre-squeezed portion 311 of the shroud 31. That is, the roller 63 also comes into contact with the tip squeezing portion 311 in order to crush the protrusion 321. An inclined portion 63a is formed on the inner lower portion of the roller 63 in order to avoid applying an excessive force to the pre-squeezed portion 311. The inclined portion 63a has a shape along the surface of the pre-squeezed portion 311. By providing the inclined portion 63a, the deformation of the pre-squeezed portion 311 can be suppressed and the protrusion 321 can be pressed.

The method for manufacturing the impeller 3 of the present embodiment includes, after the fifth step, a sixth step of turning the base plate 30 and the shroud 31 sandwiching the blade 32 upside down. In the fifth step of the present embodiment, the shroud 31 is placed on the base plate 30 and the shroud 31 that sandwich the blade 32. Therefore, in the sixth step, the base plate 30 and the shroud 31 sandwiching the blade 32 are placed on the jig 61 with the base plate 30 facing up. In the present embodiment, the jig 61 is replaced before the upside down is performed. This is because the base plate 30 and the shroud 31 have different shapes.

The method for manufacturing the impeller 3 of the present embodiment includes a seventh step of crimping the shroud 31 and the base plate 30 that are not crimped to the blade 32 in the fifth step. In the present embodiment, the shroud 31 and the blade 30 are crimped in the fifth step. Therefore, in the seventh step, the base plate 30 and the blade 32 are crimped. The seventh step is a caulking step. The caulking device 6 is also used in the seventh step, and the caulking method is the same.

In the present embodiment, it is convenient because the shroud 31 and the blade 32 can be crimped and fixed, and the base plate 30 and the blade 32 can be crimped and fixed by turning upside down using one caulking device 6. In the impeller 3 formed by this, in the plan view from one side (upper side) in the axial direction, the axial tip portion of the protrusion 321 is biased with respect to the through hole 313 in the circumferential direction and the other side (lower side) in the axial direction. The axial tip of the protrusion 321 is biased with respect to the through hole 302 in the plan view from the above. In the comparison of FIGS. 11 and 12, the protrusions 321 are both biased to the same side in the circumferential direction. Due to this bias, there is a difference between the area of the first exposed portion 33a and the area of the second exposed portion 33b described above. In the caulking step described above, it is also possible to switch the rotation direction of the roller 63 of the caulking device 6 when the impeller 3 is turned upside down. In the impeller 3 configured at that time, in the plan view from one side (upper side) in the axial direction, the axial tip portion of the protrusion 321 is biased with respect to the through hole 313 in the circumferential direction and the other side in the axial direction (lower side). In a plan view from the side), the direction in which the axial tip of the protrusion 321 is biased with respect to the through hole 302 is different. As a result, for example, in a plan view from one side (upper side) in the axial direction, when each protrusion 321 is crimped, the axial tip portion of each protrusion 321 is biased in the same circumferential direction with respect to the root side. The quality of caulking is stable.

In the method for manufacturing the impeller 3 of the present embodiment, in the caulking step, the protrusion 321 is crushed while applying a force in the axial direction and the circumferential direction by using a roller 63 that swivels in the circumferential direction. Therefore, in the configuration of the present embodiment, it is possible to prevent a large force from being applied to the blade 32 in only one direction. Further, in the method for manufacturing the impeller 3 of the present embodiment, a plurality of rollers 63 arranged at equal intervals in the circumferential direction are used. Therefore, the crimping step can be performed while evenly applying a load to the crimping target from a plurality of directions. Therefore, according to this configuration, it is possible to manufacture an impeller with less plastic deformation of the blade and less rattling. Further, the impeller 3 incorporated in the blower 1 can rotate at high speed with little rattling.

The number of the plurality of rollers 63 used in the caulking step may be appropriately changed. However, the number of the plurality of rollers 63 is preferably a divisor of the number of the blades 32. In this embodiment, the number of blades 32 is 14. For this reason, the number of rollers 63 is preferably two or seven. When the number of rollers 63 and the number of blades 32 satisfy the above relationship, the caulking step can be performed while uniformly applying a load to each blade 32. According to this method, the impeller 3 with less rattling can be manufactured.

When the caulking step is performed using the roller 63, the amount of the protrusion 321 protruding from the surface of the impeller 3 can be reduced by firmly contacting the roller 63 with the caulking target. In the impeller 3 formed in this way, for example, as shown in FIG. 11, on the axial one-side end surface (upper end surface) 31a of the shroud 31, a roller mark 34, which is a mark of contact with the roller 63, is formed around the through hole 313. It is formed. The roller marks 34 are formed in a band shape, for example, by gathering a plurality of streaky scratches. The caulking process can be performed by moving the roller 63 in one direction in the circumferential direction. As shown in FIG. 11, the roller mark 34 may be formed only on one side in the circumferential direction of the through hole 321. Here, one side in the circumferential direction is the upstream side in the turning direction of the roller 63. The roller marks 34 may be formed around the through holes 302 on the other end surface (lower end surface) 30a of the base plate 30 in the axial direction.
<4. Modification example>

The impeller 3 may have a configuration in which a coating material is applied to at least a part of the connection portion between the blade 32 and the base plate 30 or the shroud 31. The coating material may be, for example, a paint or an adhesive. The coating material may be applied to, for example, a portion where the auxiliary protrusion 322 is inserted into the auxiliary through hole 311. The coating material may be applied, for example, to the entire surface of at least one of the base plate 30 and the shroud 31. The coating material can reduce the gap formed between the blade 32 and the base plate 30 or the shroud 31 and suppress air leakage.

FIG. 16 is a schematic cross-sectional view showing a first modification of the through hole 313 provided in the shroud 31 included in the impeller 3 according to the embodiment of the present invention. FIG. 16 is a cross-sectional view of the shroud 31 cut along the circumferential direction. The configuration of the first modification is different from the configuration of the above-described embodiment in the shape of the second portion 313b. The second portion 313b has a curved surface 3133 extending from the upper end of the inner wall 3131 to the upper end of the shroud 31. The curved surface 3133 makes the width of the hole wider than that of the first portion 313a. In this example, the curved surface 3133 is a convex surface. A concave surface may be used instead of the convex surface. In this example, the curved surfaces 3133 facing each other in the circumferential direction have the same curvature. That is, the second portion 313b has a cross-sectional shape symmetrical in the circumferential direction. The configuration of the first modification may be applied to the second portion 302b provided on the base plate 30.

FIG. 17 is a schematic cross-sectional view showing a second modification of the through hole 313 provided in the shroud 31 included in the impeller 3 according to the embodiment of the present invention. FIG. 17 is a cross-sectional view of the shroud 31 cut along the circumferential direction. The configuration of the second modification is different from the configuration of the above-described embodiment in the shape of the second portion 313b. The second portion 313b includes a second inner wall 3134 extending axially upward from a position displaced in the circumferential direction from the upper end portion of the first inner wall 3131 constituting the first portion 302a to the upper end of the shroud 31. Have. The first inner wall 3131 and the second inner wall 3134 have a step. The second inner wall 3134 is provided at a position where the distance between the surfaces facing each other in the circumferential direction is increased as compared with the first inner wall 3131. In this example, the size of the step is the same between the inner walls facing each other in the circumferential direction. That is, the second portion 313b has a cross-sectional shape symmetrical in the circumferential direction. The configuration of this second modification may be applied to the second portion 302b provided on the base plate 30.

FIG. 18 is a schematic cross-sectional view showing a third modification of the through hole 313 provided in the shroud 31 included in the impeller 3 according to the embodiment of the present invention. The configuration of the third modification is different from the configuration of the above-described embodiment in the shape of the second portion 313b. The second portion 313b has an inclined surface 3132, but the magnitude of the inclined angle differs between the inclined surfaces 3132 facing in the circumferential direction. The inclination angle is an angle with respect to the upper end surface 31a of the shroud 31. In other words, in this example, the second portion 313b has an asymmetric cross-sectional shape in the circumferential direction. In the configuration of this example, when the axial tip of the protrusion 321 is caulked and fixed by using the roller 63 that swivels in the circumferential direction, the possibility that the axial tip of the protrusion 321 protrudes from the through hole 313 can be reduced. The configuration of the third modification may be applied to the second portion 302b provided on the base plate 30.

In the above, both the base plate 30 and the shroud 31 have through holes 302 and 313. However, this is just an example. At least one of the base plate and the shroud may have a through hole for inserting a protrusion. When the through hole is provided in only one of them, the configuration of the protrusion provided on the blade is also changed from the configuration of the above-described embodiment.

The embodiments and modifications shown above are merely examples of the present invention. The configurations of the embodiments and modifications may be appropriately changed without exceeding the technical idea of the present invention. Moreover, the embodiment and a plurality of modifications may be carried out in combination to the extent possible.

The impeller of the present invention can be used, for example, in a blower. In the blower device provided with the impeller of the present invention, a blower device having an impeller with high ventilation efficiency can be realized. The present invention is suitable for, for example, a vacuum cleaner, but can also be used for other electronic devices.

1 ... blower, 2 ... motor, 3 ... impeller, 3'... impeller before caulking, 4 ... impeller cover, 4a ... guide wall, 5 ... control board, 6 ... caulking device, 20 ... motor cover, 21 ... rotor, 22 ... stator, 23 ... shaft, 24a ... upper bearing, 24b ... lower bearing, 25 ... -Sensor board, 25a ... Rotation sensor, 30 ... Base plate, 30a ... Axial other side end face, 31 ... Shroud, 31a ... Axial one side end face, 32 ... Blade, 32a ... 1st blade, 32aa ... Rectangular part, 32ab ... Wide part, 32b ... 2nd blade, 33a ... 1st exposed part, 33b ... 2nd exposed part , 34 ... Roller mark, 40 ... Upper wall part, 40a ... Projection part, 40b ... Cover opening, 40c ... Reinforcing rib, 41 ... Side wall part, 50 ... Electric field capacitor , 60 ... pedestal, 61 ... jig, 62 ... swivel part, 63 ... roller, 301 ... shaft opening, 301a ... arc part, 301b ... straight part, 302 ... through hole, 302a ... first part, 302b ... second part, 303 ... auxiliary through hole, 311 ... tip squeezing part, 311a ... opening, 312 ...・ Flat plate part, 313 ・ ・ ・ through hole, 321 ・ ・ ・ protrusion, 321a ・ ・ ・ axial tip surface, 322 ・ ・ ・ auxiliary protrusion, 3021 ・ ・ ・ inner wall, 3022 ・ ・ ・ inclined surface, 3131 ... Inner wall (first inner wall), 3132 ... inclined surface, 3133 ... curved surface, 3134 ... second inner wall, A ... central axis

Claims (11)

An impeller that rotates around a rotation axis
A base plate that extends in the direction orthogonal to the axial direction,
A shroud located on one side of the base plate and facing the base plate at an axial distance.
A blade arranged between the base plate and the shroud,
Have,
At least one of the shroud and the base plate has a through hole that penetrates in the axial direction.
The blade has a protrusion that is inserted into the through hole and has an axial tip that is caulked and fixed.
The radial inner side of the blade is located on one side in the circumferential direction with respect to the radial outer side of the blade.
The through hole is
The first part into which the root side of the protrusion is inserted and
A second portion in which the tip end side of the protrusion is inserted and is wider in the circumferential direction than the first portion, and
Have,
In a plan view from at least one of one side and the other side in the axial direction, a gap is formed between the protrusion and the inner wall constituting the second portion.
In a plan view from at least one of one side in the axial direction and the other side, the number of the through holes located on one side in the circumferential direction is larger than the area of the gap located on the other side in the circumferential direction. An impeller in which the area of the gap located on one side is larger than the number of through holes smaller than the area of the gap located on the other side in the circumferential direction. An impeller that rotates around a rotation axis
A base plate that extends in the direction orthogonal to the axial direction,
A shroud located on one side of the base plate and facing the base plate at an axial distance.
A blade arranged between the base plate and the shroud,
Have,
At least one of the shroud and the base plate has a through hole that penetrates in the axial direction.
The blade has a protrusion that is inserted into the through hole and has an axial tip that is caulked and fixed.
The radial inner side of the blade is located on one side in the circumferential direction with respect to the radial outer side of the blade.
The through hole is
The first part into which the root side of the protrusion is inserted and
A second portion in which the tip end side of the protrusion is inserted and is wider in the circumferential direction than the first portion, and
Have,
The axial tip surface of the protrusion is flush with the axial one-sided end face of the shroud or the axially opposite end face of the base plate.
In a plan view from at least one of one side in the axial direction and the other side, the number of the through holes located on one side in the circumferential direction is larger than the area of the gap located on the other side in the circumferential direction. An impeller in which the area of the gap located on one side is larger than the number of through holes smaller than the area of the gap located on the other side in the circumferential direction. It has a plurality of the through holes into which the protrusions are inserted,
Claims that the total area of the gaps located on one side in the circumferential direction and the total area of the gaps located on the other side in the circumferential direction are different in a plan view from at least one side in the axial direction and the other side. Item 1. The impeller according to item 1 or 2. Both the shroud and the base plate have the through holes.
In the plan view from one side in the axial direction, the axial tip of the protrusion is biased with respect to the through hole, and in the plan view from the other side in the axial direction, the axial tip of the protrusion is the through hole. The impeller according to any one of claims 1 to 3, wherein the direction of bias is the same. Both the shroud and the base plate have the through holes.
In the plan view from one side in the axial direction, the axial tip of the protrusion is biased with respect to the through hole, and in the plan view from the other side in the axial direction, the axial tip of the protrusion is the through hole. The impeller according to any one of claims 1 to 3, which is different from the direction biased with respect to. The impeller according to any one of claims 1 to 5, wherein a coating material is applied to at least a part of the connection portion between the blade and the base plate or the shroud. A blower comprising the impeller according to any one of claims 1 to 6. A method of manufacturing an impeller that rotates around a rotation axis.
A base plate that extends in a direction orthogonal to the axial direction of the impeller, a shroud that is located on one side of the base plate and faces the base plate at an axial distance, and is arranged between the base plate and the shroud . The first step of preparing a blade whose inside in the radial direction is located on one side in the circumferential direction from the outside in the radial direction , and
A second step of forming axially extending protrusions on at least one of the blades on one side and the other side in the axial direction.
A first portion into which the root side of the protrusion is inserted into at least one of the shroud and the base plate, and a second portion in which the tip end side of the protrusion is inserted and the width in the circumferential direction is wider than that of the first portion. The area of the gap located on one side in the circumferential direction is larger than the area of the gap located on the other side in the circumferential direction in a plan view from at least one side in the axial direction and the other side. The number of through holes is increased in the third step in which the area of the gap located on one side in the circumferential direction is larger than the number of through holes smaller than the area of the gap located on the other side in the circumferential direction.
A fourth step of inserting the protrusion into the through hole and sandwiching the blade between the base plate and the shroud.
A fifth step of crimping the shroud or the base plate and the blade.
A method for manufacturing an impeller. In the second step, the protrusions are formed on both one side and the other side in the axial direction.
In the third step, the through holes are formed in both the shroud and the base plate.
After the fifth step, the sixth step of flipping the base plate and the shroud that sandwich the blade upside down together.
Of the shroud and the base plate, the seventh step of crimping the blade that was not crimped with the blade in the fifth step is
The method for producing an impeller according to claim 8, further comprising. The method for manufacturing an impeller according to claim 8 or 9, wherein a plurality of rollers arranged at equal intervals in the circumferential direction are used in the caulking step. The method for manufacturing an impeller according to claim 10, wherein the number of the plurality of rollers is a divisor of the number of the blades.