Impeller cup and fan

Abstract

To provide an impeller cup improved in concentration of stress.SOLUTION: An impeller cup made of a resin, covers a rotor of an outer rotor motor rotating on a center shaft as a center, from an axial one side. The impeller cup has a top plate portion radially expanded at the axial one side, and the axial one side of the top plate portion has: a first circular arc extending in a circumferential direction with respect to the center shaft as a center; a first recessed portion having a second circular arc extending in the circumferential direction with respect to the center shaft as the center at an inner diameter side of the first circular arc and recessed into a cylindrical shape at the axial other side; and a plurality of one-side ribs connecting the first circular arc and the second circular arc in the radial direction, and the first recessed portion has a gate trace.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an impeller cup and a fan. [Background technology]

[0002] Impeller cups of axial fans used for cooling office automation equipment, etc., are manufactured by, for example, injection molding. In the invention described in Patent Document 1, when manufacturing parts by injection molding using a pin gate, the periphery of the gate mark that is generated when the resin injected from the gate is cut is recessed concentrically, so that the gate mark does not protrude on the surface, making it unnecessary to perform a process of removing the gate mark. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 2579860 Summary of the Invention [Problem to be solved by the invention]

[0004] In axial fans that use outer rotor motors, the impeller cup that connects the blades and the rotor is subjected to a large amount of stress. If the impeller cup and blades are molded using an injection mold, defects may occur due to stress generated near the welds and pin gates during thermal shock tests.

[0005] In the conventional structure in which the periphery of the gate mark is recessed concentrically, large stress is concentrated around the gate mark, which may result in defects such as breakage around the gate mark.

[0006] Thus, conventionally, there is room for improvement in the concentration of stress on the impeller cup.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an impeller cup with improved stress concentration. [Means for solving the problem]

[0008] A first exemplary invention of the present application is an impeller cup made of resin that covers a rotor of an outer rotor motor that rotates around a central axis from one axial side, the impeller cup having a top plate portion that extends radially on one axial side, the one axial side of the top plate portion having a first circular arc extending circumferentially around the central axis, and a first recess that is cylindrically recessed on the other axial side and has a second circular arc extending circumferentially around the central axis on the inner diameter side of the first arc, and a plurality of one-side ribs that radially connect the first arc and the second arc, and the first recess has a gate mark. Effect of the Invention

[0009] According to the first exemplary aspect of the present invention, it is possible to provide an impeller cup which is improved in terms of stress concentration. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a fan equipped with an impeller cup according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a bottom view of the fan 10 shown in FIG. [Diagram 3] 2 is a side cross-sectional view of the fan 10 shown in FIG. [Figure 4] 2 is a plan view of the impeller cup 100 and the blade 200 shown in FIG. 1. [Diagram 5] 2 is a perspective view of the impeller cup 100 and the blade 200 shown in FIG. 1. [Figure 6] FIG. 13 is a contour diagram showing the results of a thermal shock stress analysis on one axial side of an impeller cup. [Figure 7] FIG. 13 is a contour diagram showing the results of a thermal shock stress analysis on the other axial side of the impeller cup. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an impeller cup according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the scale and number of each component may be different from the actual structure in order to make each component easier to understand.

[0012] In addition, in the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional Cartesian coordinate system. In the XYZ coordinate system, the Z axis direction is parallel to the axis of the central axis J shown in Fig. 1. The X axis direction is the left-right direction in Fig. 2 among the radial directions with respect to the central axis J. The Y axis direction is perpendicular to both the X axis direction and the Z axis direction. In each of the X axis direction, the Y axis direction, and the Z axis direction, the side indicated by the arrow in the drawing is the + side, and the opposite side is the - side.

[0013] In the following description, the positive side (+Z side) in the Z-axis direction is called the "front side" or "one side", and the negative side (-Z side) in the Z-axis direction is called the "rear side" or "other side". The rear side (other side) and the front side (one side) are names used simply for the purpose of description and do not limit the actual positional relationship and direction. Unless otherwise specified, the direction parallel to the central axis J (Z-axis direction) is simply called the "axial direction", the radial direction centered on the central axis J is simply called the "radial direction", and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J, is simply called the "circumferential direction". The side approaching the central axis J in the radial direction is called the "radial inner side", and the side moving away from the central axis J is called the "radial outer side". In the circumferential direction, the side indicated by the arrow in FIG. 1 is the +θ side (one circumferential side), and the opposite side is the -θ side (the other circumferential side).

[0014] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction (Z-axis direction) but also extending in a direction tilted at an angle of less than 45° to the axial direction. In addition, in this specification, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction (Z-axis direction), but also extending in a direction tilted at an angle of less than 45° to the radial direction. Furthermore, "parallel" includes not only being strictly parallel but also being tilted at an angle of less than 45° to each other.

[0015] [First embodiment] FIG. 1 is a perspective view showing a fan equipped with an impeller cup according to one embodiment of the present invention. The fan 10 has an impeller cup 100, blades 200 fixed to the impeller cup 100, a motor 400 (see FIG. 3) that rotates the impeller cup 100, and a housing 300 that houses the impeller cup 100, the blades 200, and the motor 400. Seven blades 200 are arranged radially outside the impeller cup 100 along the circumferential direction.

[0016] FIG. 2 is a bottom view of the fan 10 shown in FIG. The fan 10 has a motor case 310 that houses a motor 400, and ribs 320 that support the motor case 310. The housing part 300 supports the motor case 310 via the ribs 320. The ribs 320 extend radially outward from the motor case 310 to reach the housing part 300. Four ribs 320 are arranged along the circumferential direction.

[0017] Fig. 3 is a side cross-sectional view of the fan 10 shown in Fig. 1. Fig. 3 is a side cross-sectional view taken along a plane perpendicular to the X-axis and passing through the central axis J. The motor 400 is an outer rotor motor. The motor 400 includes a stator 410, a rotor 420, a shaft 430, and bearings 440 and 450 that support the shaft 430. The rotor 420 is disposed radially outside the stator 410.

[0018] The rotor 420 is disposed radially outside the stator 410. The impeller cup 100 covers the rotor 420 from one axial side. The impeller cup 100 is a resin member, and is manufactured by insert molding in a mold in which the rotor 420 and the shaft 430 are disposed. The shaft 430 extends along the central axis J.

[0019] The motor case 310 has a base portion 311 that expands in the radial direction on the other axial side, and a cylindrical portion 312 that extends from the base portion 311 to one axial side. The base portion 311 is fixed to the housing portion 300 by a rib 320. The bearings 440 and 450 are fixed to the inner periphery side of the cylindrical portion 312 and support the shaft 430. The stator 410 is fixed to the outer periphery side of the cylindrical portion 312. The fan 10 blows air from the other axial side to the one axial side by rotating the rotor 420 around the central axis J in the -θ direction.

[0020] FIG. 4 is a plan view of the impeller cup 100 and the blades 200 shown in FIG. The impeller cup 100 has a top plate portion 110 that extends in the radial direction. The surface 101 is a surface on one axial side of the top plate portion 110. The one axial side of the top plate portion has a first circular arc 111 that extends in the circumferential direction about the central axis J, a second circular arc 112 that extends in the circumferential direction about the central axis J on the inner diameter side of the first circular arc 111, and a first recessed portion 115 that is cylindrically recessed from the surface 101 to the other axial side. The axial depth of the first recessed portion 115 is, for example, 0.5 mm. The length from the central axis J to the radially outer end of the top plate portion 110 is 3 to 4 times the length from the central axis J to the first circular arc 111.

[0021] One axial side of the top plate portion 110 has a first recess 115 and a one-side rib 113 between the first recess 115 and the first recess 115 adjacent to the first recess 115 in the circumferential direction. The first recess 115 is divided into three recesses by the one-side rib 113. The axial position of the one axial side end face of the one-side rib 113 is the same as the axial position of the surface 101. The one-side rib 113 radially connects the first circular arc 111 and the second circular arc 112. The one-side rib 113 has an inner radial width (circumferential length) and an outer radial width that are equal. The width of the one-side rib 113 is, for example, 2.0 mm.

[0022] The first recess 115 has a gate mark 114. The gate mark 114 is a mark left by cutting resin from a pin gate that fills the resin into a mold when insert molding the impeller cup 100. The impeller cup 100 has one gate mark 114 in each of the first recess 115 that is divided into three recesses by the one-side rib 113. The gate mark 114 is located midway between the first circular arc 111 and the second circular arc 112 in the radial direction, and midway between the one-side rib 113 and the other one-side rib 113 in the circumferential direction.

[0023] Fig. 5 is a perspective view of the impeller cup 100 and the blades 200 shown in Fig. 1. Fig. 5 is a perspective view showing the other axial side of the impeller cup 100. The other axial side of the top plate portion 110 has a protruding portion 150 extending in a columnar shape on the other axial side, and a surface 151 on the other axial side end of the protruding portion 150. In this embodiment, the protruding portion 150 is cylindrical, but the present invention is not limited to this, and the protruding portion 150 may be prismatic, conical, or pyramidal. Also, as shown in Fig. 3, an outer portion 150a of the protruding portion 150 overlaps with the first circular arc 111 in the axial direction.

[0024] The protruding portion 150 has a second recess 152 recessed in a cylindrical shape on one side in the axial direction, and a plurality of first ribs 153 and second ribs 154 dividing the second recess 152 in the circumferential direction. The second recess 152 recesses from the surface 151 on one side in the axial direction. The axial depth of the second recess 152 is, for example, 0.9 mm. The first rib 153 and the second rib 154 are an example of a plurality of other-side ribs dividing the second recess 152 in the circumferential direction. Three first ribs 153 are arranged along the circumferential direction. Three second ribs 154 are arranged along the circumferential direction. The second recess 152 is divided into six parts along the circumferential direction by the first rib 153 and the second rib 154.

[0025] The first rib 153 has an equal radially inner width and a radially outer width. The width of the first rib 153 is, for example, 2.0 mm. The first rib 153 faces the gate mark 114 on one axial side of the top plate portion 110. At least a portion of the first rib 153 overlaps with the gate mark 114 in the axial direction.

[0026] The second rib 154 has a smaller width than the first rib 153. The width of the second rib 154 is 30 to 50% of the width of the first rib 153. The second rib 154 has the same width on the radially inner side and the radially outer side. The width of the second rib 154 is, for example, 0.8 mm. The second rib 154 faces the one-side rib 113 on one axial side of the top plate portion 110 in the axial direction. At least a portion of the second rib 154 overlaps with the one-side rib 113 in the axial direction.

[0027] Fig. 6 is a contour diagram showing the results of thermal shock stress analysis on one axial side of the impeller cup. Fig. 6(A) is a diagram showing a conventional impeller cup, and Fig. 6(B) is a diagram showing the impeller cup 100 of this embodiment. The conventional impeller cup in Fig. 6(A) is an impeller cup having a structure having a recess 1115 that is recessed concentrically around a gate mark 1114.

[0028] As shown in Fig. 6(A), in the past, stress was concentrated around the gate mark 1114, and it can be seen that a large amount of stress was applied around the gate mark 1114. In contrast, as shown in Fig. 6(B), in the impeller cup 100 of this embodiment, stress is dispersed without being concentrated around the gate mark 114. With the impeller cup 100 of this embodiment, the occurrence of defects can be suppressed by dispersing the stress.

[0029] Fig. 7 is a contour diagram showing the results of a thermal shock stress analysis on the other axial side of the impeller cup, Fig. 7(A) is a diagram showing a conventional impeller cup, and Fig. 7(B) is a diagram showing the impeller cup 100 of this embodiment. The conventional impeller cup in FIG. 7(A) is the same as the impeller cup in FIG. 6(A).

[0030] As shown in Fig. 7(A), in the conventional case, there are some places where stress is concentrated on the other axial side as well. In contrast, as shown in Fig. 7(B), in the impeller cup 100 of this embodiment, stress is dispersed on the other axial side as well. With the impeller cup 100 of this embodiment, this stress dispersion can suppress the occurrence of defects.

[0031] <Actions and Effects of Impeller Cup 100 and Fan 10> Next, the operation and effect of the impeller cup 100 and the fan 10 will be described.

[0032] In the invention relating to the above-mentioned embodiment, there is provided an impeller cup made of resin that covers a rotor of an outer rotor motor that rotates around a central axis from one axial side, the impeller cup having a top plate portion that extends radially on one axial side, the one axial side of the top plate portion having a first circular arc extending circumferentially around the central axis and a second circular arc extending circumferentially around the central axis on the inner diameter side of the first arc, a first recess that is cylindrically recessed on the other axial side, and a plurality of one-side ribs that radially connect the first arc and the second arc, and the first recess has a gate mark. Therefore, the first recess can prevent stress concentration, and the occurrence of defects can be suppressed.

[0033] Further, the gate mark is located midway between the first circular arc and the second circular arc in the radial direction, and midway between the one side rib and the other one side rib in the circumferential direction. Therefore, the flow of resin within the first recess during molding becomes symmetrical, which makes it possible to prevent stress concentration and suppress the occurrence of defects.

[0034] Moreover, the first recess is divided into three recesses by the one-side rib, and the gate marks are disposed in each of the three recesses. For this reason, by arranging three pin gates in the circumferential direction, filling during molding can be made smoother, and strength can be further increased.

[0035] Furthermore, the length from the central axis to the radially outer end of the top plate portion is 3 to 4 times the length from the central axis to the first circular arc. Therefore, the first recess can prevent stress concentration, and the occurrence of defects can be suppressed.

[0036] Moreover, the one-side rib has an equal width on the radially inner side and on the radially outer side. Therefore, the first recess can prevent stress concentration, and the occurrence of defects can be suppressed.

[0037] The other axial side of the top plate portion has a protrusion extending in a columnar shape on the other axial side, and at least a portion of an outer portion of the protrusion overlaps with the first circular arc in the axial direction. Therefore, the strength of the position of the first arc can be increased by the protrusion.

[0038] The protruding portion on the other axial side of the top plate portion has a second recess that is cylindrically recessed on one axial side within the protruding portion, and a plurality of other-side ribs that divide the second recess in the circumferential direction. Therefore, the weight can be reduced while maintaining strength by the other side rib.

[0039] The other-side rib has a first rib and a second rib that is narrower than the first rib, the first rib facing the gate mark in the axial direction, and the second rib facing the one-side rib in the axial direction. Therefore, the first rib acts as a molten metal retainer, making filling during molding smoother and increasing strength.

[0040] The width of the second rib is 30 to 50% of the width of the first rib. This allows for a reduction in weight while maintaining strength.

[0041] Moreover, the other-side rib has an equal radially inner width and a radially outer width. This allows for a reduction in weight while maintaining strength.

[0042] The fan also includes the impeller cup, the outer rotor motor that rotates the impeller cup, and a plurality of blades fixed to the impeller cup. This makes it possible to prevent stress concentration in the impeller cup of the fan, thereby suppressing the occurrence of malfunctions.

[0043] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. These embodiments and modifications are included in the scope and gist of the present invention, and are also included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0044] 10 Fan 100 Impeller Cup 101 Top plate 110 sides 111 First Arc 112 Second Arc 113 One side rib 114 Gate Remains 115 First recess

Claims

1. An impeller cup made of resin covers a rotor of an outer rotor motor that rotates around a central axis from one axial side, The impeller cup has a top plate portion that extends radially on one axial side, One axial side of the top plate portion is a first recessed portion including a first arc extending in a circumferential direction around the central axis and a second arc extending in a circumferential direction around the central axis on an inner diameter side of the first arc, the first recessed portion being cylindrically recessed toward the other axial side; a plurality of one-side ribs connecting the first circular arc and the second circular arc in a radial direction; having The first recess has a gate mark. Impeller cup.

2. The gate mark is At a radial midpoint between the first arc and the second arc, Located midway between the one-side rib and the other one-side rib in the circumferential direction, The impeller cup of claim 1 .

3. The first recess is divided into three recesses by the one-side rib, The gate marks are disposed in each of the three recesses. The impeller cup according to claim 1 or 2.

4. The length from the central axis to the radially outer end of the top plate portion is 3 to 4 times the length from the central axis to the first circular arc. An impeller cup according to any one of claims 1 to 3.

5. The one-side rib has a radially inner width and a radially outer width that are equal to each other. An impeller cup according to any one of claims 1 to 4.

6. The other axial side of the top plate portion has a protrusion extending in a columnar shape on the other axial side, At least a portion of an outer portion of the protrusion overlaps with the first circular arc in the axial direction. An impeller cup according to any one of claims 1 to 5.

7. The convex portion on the other axial side of the top plate portion is a second recessed portion that is recessed in a cylindrical shape toward one axial direction within the protruding portion; A plurality of other-side ribs dividing the second recess in a circumferential direction; having The impeller cup of claim 6.

8. The other-side rib has a first rib and a second rib having a width smaller than that of the first rib, The first rib faces the gate mark in the axial direction, The second rib faces the one-side rib in the axial direction. The impeller cup of claim 7.

9. The width of the second rib is 30 to 50% of the width of the first rib. The impeller cup of claim 8.

10. The other side rib has a radially inner width and a radially outer width that are equal to each other. An impeller cup according to any one of claims 7 to 9.

11. An impeller cup according to any one of claims 1 to 10; the outer rotor motor that rotates the impeller cup; a plurality of vanes secured to the impeller cup; having fan.

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