IMPELLER STRUCTURE

Abstract

An impeller structure includes a hub, a plurality of blades, and a plurality of reinforcing ribs. The blades are extended from the hub, and the reinforcing ribs are disposed annularly and separately between the blades. The strength of the impeller structure is improved by the reinforcing ribs, and the interference between the inner and outer flow fields of the blades is reduced by the reinforcing ribs. Also, a fan including above-mentioned impeller structure is disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of Taiwan Patent Application No. 100110236, filed on Mar. 25, 2011, the entirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an impeller structure, and in particular to an impeller structure with reinforcing ribs.

2. Description of the Related Art

In general, large-scale fans used in air-conditioning systems have a large size and high rotating speed. For strength purposes, one solution for impellers of large-scale fans are that they are made from metal. However, due to very high precision requirements for the mold for making a metal impeller, much labor and resources are needed, thus increasing development costs. Further, the consistency of the quality of the metal impeller made by a mold is not stable. Also, the cost of metal is high.

Another solution is for the impeller to be made from plastic. However, the strength of plastic may be inefficient. For example, under high temperatures at high rotation speeds, a plastic impeller may deform more easily. Please refer to FIG. 1. To improve the strength of the impeller 100, a fixed ring 120 is disposed on ends of blades 110. However, the flow field of the impeller structure is completely separated by the fixed ring 120, and the flow field within the fixed ring 120 interferes with the flow field on the outside of the fixed ring 120. Note that the weight of the impeller 100 is greatly increased due to the fixed ring 120.

BRIEF SUMMARY OF THE INVENTION

To solve the problems of the prior art, the object of the invention is to provide an impeller structure and a fan. The fan includes the impeller structure. The impeller structure includes a plurality of reinforcing ribs and a plurality of blades. The reinforcing ribs are disposed between the blades, and located between side edges and connecting edges of the blades, and thus the balance of the blades is improved without sacrificing strength thereof, and the interference of the flow fields is reduced.

For the above objective, the impeller structure includes a hub, a plurality of blades, and a plurality of reinforcing ribs. The hub is rotated about a rotation axis, and has an outer surface. The blades are extended from the outer surface. Each of the blades has a windward surface and a leeward surface opposite to the windward surface. Further, each of the blades has a side edge, a connecting edge opposite to the side edge, a trailing edge, and a leading edge opposite to the trailing edge thereof. The side edge is distant from the hub, and the connecting edge is connected to the hub. The reinforcing ribs are annularly and separately disposed on the blades, and located between the side edges and the connecting edges of the blades. An end of one of the reinforcing ribs is connected to the windward surface of one of the blades, and the other end of the one of the reinforcing ribs is connected to a leeward surface of an adjacent blade. Moreover, the end of the one of the reinforcing ribs is adjacent to the leading edge of the blade and is distant from the trailing edge of the blade. The other end of the one of the reinforcing ribs is adjacent to a trailing edge of the adjacent blade and is distant from a leading edge of the adjacent blade.

For the above objective, the impeller structure includes a hub, a plurality of sub-blades, a separation ring, a plurality of blades, and a plurality of reinforcing ribs. The hub is rotated about a rotation axis, and has an outer surface. The sub-blades are radiantly extended from the outer surface of the hub, respectively. The separation ring is disposed on the end of the sub-blades. The blades are extended from the separation ring opposite to the sub-blades. Each of the blades has a windward surface and a leeward surface opposite to the windward surface. Further, each of the blades has a side edge, a connecting edge opposite to the side edge, a trailing edge, and a leading edge opposite to the trailing edge. The side edge is distant from the separation ring, and the connecting edge is connected to the separation ring. The reinforcing ribs are annularly and separately disposed on the blades, and located between the side edges and the connecting edges of the blades. An end of one of the reinforcing ribs is connected to the windward surface of one of the blades, and the other end of the one of the reinforcing ribs is connected to a leeward surface of an adjacent blade. Moreover, the end of the one of the reinforcing ribs is adjacent to the leading edge of the blade and is distant from the trailing edge of the blade. The other end of the one of the reinforcing ribs is adjacent to a trailing edge of the adjacent blade and is distant from a leading edge of the adjacent blade.

In conclusion, by the structure of the reinforcing ribs and the blades, the strength of the impeller structure can be improved. Thus, the impeller structure may be made by plastic, and the cost of the impeller structure can be decreased. Moreover, the manufacturing of the impeller structure is easier and more precise. The weight of the blades is reduced due to the small size and light weight of the reinforcing ribs, and thus the balance of the rotation of the impeller structure is improved. In addition, the blades are not completely separated into two parts by the reinforcing ribs, and thus the interference between the inner and outer flow fields of the impeller structure can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

FIG. 1 is a perspective view of an impeller structure of the prior art;

FIG. 2 is a perspective view of an impeller structure of a first embodiment of the invention;

FIG. 3 is a top view of the impeller structure of the first embodiment of the invention;

FIG. 4 is a side view of the impeller structure of the first embodiment of the invention;

FIG. 5 is a cross-sectional view of the reinforcing rib along AA line of FIG. 4;

FIG. 6 is a perspective view of an impeller structure of a second embodiment of the invention; and

FIG. 7 is a top view of the impeller structure of the second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Please refer to FIG. 2 to FIG. 4. FIG. 2 is a perspective view of an impeller structure of a first embodiment of the invention. FIG. 3 is a top view of the impeller structure of the first embodiment of the invention. FIG. 4 is a side view of the impeller structure of the first embodiment of the invention. The impeller structure 200 may be connected to a motor (not shown in the figures) to form a fan. The impeller structure 200 is driven by the motor to generate an air flow. It is noted that the impeller structure can be used in a fan.

The impeller structure 200 may be made from plastic. The impeller structure 200 includes a hub 210, a plurality of blades 220, and a plurality of reinforcing ribs 230. The hub 210 is circular disc shaped with a hollow structure. The hub 210 is disposed on the motor, and driven by the motor to rotate about a rotation axis AX1. Further, the hub 210 has an outer surface 211.

Each of the blades 220 is a thin stripped structure, and may be made from plastic. The blades 220 are radiantly extended from the outer surface 211. There is a separation space S1 between two of the blades 220. Each of the blades 220 has a windward surface 221 and a leeward surface 222. The windward surface 221 and the leeward surface 222 are located at two opposite sides of the blade 220, and occupy most of the surface area of the blade 220. The windward surface 221 faces an area where the air flow flows into the impeller structure 200, and the leeward surface 222 faces an area where the air flow flows out of the impeller structure 200.

Each of the blades 220 has a side edge 223, a connecting edge 224, a trailing edge 225, and a leading edge 226. The windward surface 221 and the leeward surface 222 are surrounded by the side edge 223, the connecting edge 224, the trailing edge 225, and the leading edge 226. The side edge 223 and the connecting edge 224 are disposed on two opposite sides of the blade 220. The side edge 223 is distant from hub 210, and the connecting edge 224 is connected to the hub 210.

The trailing edge 225 corresponds to an area where the air flow flows into the impeller structure 200. The leading edge 226 corresponds to an area where the air flow flows out of the impeller structure 200. The trailing edge 225 and the leading edge 226 are disposed on two opposite sides of the blade 220, and are connected to the side edge 223 and the connecting edge 224. As shown in FIG. 4, the leading edge 226 of the blade 220 is near a trailing edge 225a of an adjacent blade 220a, and is distant from a leading edge 226a of the adjacent blade 220a.

The reinforcing ribs 230 are annularly and separately disposed on the blades 220, and are located between the side edges 223 and the connecting edges 224 of the blades 220. An end of the reinforcing rib 230 is connected to the windward surface 221 of the blade 220, and the other end of the reinforcing ribs 230 is connected to the leeward surface 222a of the adjacent blade 220a. The end of the reinforcing rib 230 connected to the windward surface 221 is adjacent to the leading edge 226, and is distant from trailing edge 225. The other end of reinforcing rib 230 connected to the leeward surface 222a of the adjacent blade 220a is adjacent to the trailing edge 225a, and is distant from the leading edge 226a of the adjacent blade 220a.

As shown in FIG. 4, the blade 220 has a wing-tip chord length W2 between the trailing edge 225 and the leading edge 226. The width W1 of the reinforcing rib 230 is smaller than half of the wing-tip chord length W2 of the blade 220. In the embodiment, the width W1 of the reinforcing rib 230 is smaller than one-third the wing-tip chord length W2 of the blade 220.

As shown in FIG. 3, the reinforcing rib 230 is perpendicular to the blade 220, and the reinforcing rib 230 is connected to the blade 220 at an area from one-third to two-third of the length L1, which is from the side edge 223 to the connecting edge 224, of the blade 220. Thus, the strength of the blade 220 can be improved. Moreover, the reinforcing rib 230 is arranged along a circular track, wherein the rotation axis AX1 is at the center of the circular track. By the above arrangement, the interference of the flow field of the air flow is decreased by the reinforcing rib 230.

As shown in FIG. 4, the separation space S1 is between the windward surface 221 of the blade 220 and the leeward surface 222a of the blade 220a. The reinforcing rib 230 is extended along an extension direction D1, and the air flow flows into the impeller structure 200 along an air intake direction D2. The extension direction D1 is 45 degrees to the air intake direction D2 or the rotation axis AX1, and thus the flow resistance generated by the reinforcing rib 230 can be decreased.

The reinforcing rib 230 and the reinforcing rib 230a are connected to two opposite sides of the blade 220, and the extensions of the reinforcing rib 230 and the reinforcing rib 230a are not overlapped or crossed along the extension direction D1 or the air intake direction D2. Thus, the separation space S1 between the blade 220 and the adjacent blade 220a are not completely separated into an inner zone Z1 and an outer zone Z2 (as shown in FIG. 3) by the reinforcing rib 230. Namely, the inner zone Z1 and the outer zone Z2 between the blade 220 and the blade 220a are communicated to each other. The flow field of the air flow will not completely be separated by the reinforcing rib 230a between the blade 220 and the blade 220a, and the interference between an inner flow field in the inner zone Z1 and an outer flow field in the outer zone Z2 can be reduced.

Please also refer to FIG. 5, which is a cross-sectional view of the reinforcing rib 230 along AA line of FIG. 4. The extension direction D1 (as shown in FIG. 4) is perpendicular to the cross section of the reinforcing rib 230. In the embodiment, the cross section of the reinforcing rib 230 is rectangular with rounded ends. The ends of the reinforcing ribs 230 have a conduction current function. Thus, when the impeller structure 200 is rotated, the air flow flows through the ends of the reinforcing ribs 230 smoothly. However, the shape of the cross section of the reinforcing rib 230 is not limited. In the other embodiment, the shape of the cross section of the reinforcing rib 230 may be rectangular, an ellipse, a trapezoid or wing shaped.

Please refer to FIG. 6 and FIG. 7. FIG. 6 is a perspective view of an impeller structure 200a of a second embodiment of the invention. FIG. 7 is a top view of the impeller structure 200a of the second embodiment of the invention. The differences between the second embodiment and the first embodiment are described as following. The impeller structure 200a further includes a plurality of sub-blades 240 and a separation ring 250. The sub-blades 240 are radiantly extended from the outer surface 211 of the hub 210. The separation ring 250 is a ring structure around the hub 210. The separation ring 250 is disposed on the ends of the sub-blades 240. The blades 220 are extended from the separation ring 250. In the other words, the sub-blades 240 and the blades 220 are disposed on two opposite sides of the separation ring 250. Moreover, the length of the sub-blade 240 is smaller than the length of the blade 220, and the number of the sub-blades 240 is greater than the number of blades 220.

In the embodiment, the hub 210 is pivoted on a base (not shown in the figures), and a guide tube (not shown in the figures) is connected to the separation ring 250. An air flow is transmitted to the sub-blade 240 within the separation ring 250 by the guide tube to drive the sub-blade 240 to rotate. When the sub-blades 240 are rotated, the blades 220 of the impeller structure 200a are rotated due to the sub-blades 240, and the blades 220 drive an air flow, outside the guide tube, flowing.

In conclusion, by the structure of the reinforcing ribs and the blades, the strength of the impeller structure can be improved. Thus, the impeller structure can be made by plastic, and the cost of the impeller structure can be decreased. Moreover, the manufacturing of the impeller structure is easier and more precise. The weight of the blades is reduced due to the small size and light weight of the reinforcing ribs, and thus the balance of the rotation of the impeller structure is improved. In addition, the blades are not completely separated into two parts by the reinforcing ribs, and thus the interference between the inner and outer flow fields of the impeller structure can be reduced.

While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

Claims

1. An impeller structure, comprising:

a hub, rotated about a rotation axis, having an outer surface;

a plurality of blades extended from the outer surface, wherein each of the blades has a windward surface and a leeward surface opposite to the windward surface, and each of the blades has a side edge, a connecting edge opposite to the side edge, a trailing edge, and a leading edge opposite to the trailing edge, wherein the side edge is distant from the hub, and the connecting edge is connected to the hub; and

a plurality of reinforcing ribs, annularly and separately disposed on the blades, located between the side edges and the connecting edges of the blades,

wherein an end of one of the reinforcing ribs is connected to the windward surface of one of the blades, and the other end of the one of the reinforcing ribs is connected to a leeward surface of an adjacent blade,

wherein the end of the one of the reinforcing ribs is adjacent to the leading edge of the blade and is distant from the trailing edge of the blade, and the other end of the one of the reinforcing ribs is adjacent to a trailing edge of the adjacent blade and is distant from a leading edge of the adjacent blade.

2. The impeller structure as claimed in claim 1, wherein the width of each of the reinforcing ribs is smaller than half of a wing-tip chord length of each of the blades.

3. The impeller structure as claimed in claim 1, wherein the reinforcing rib is connected to the blade at an area from one-third to two-third of the blade 220.

4. The impeller structure as claimed in claim 1, wherein the reinforcing ribs are perpendicular to the blades, respectively.

5. The impeller structure as claimed in claim 1, wherein the cross section of each of the reinforcing ribs is rectangular, rectangular with rounded ends, an ellipse, a trapezoid, or wing shaped.

6. The impeller structure as claimed in claim 1, wherein the leading edge of the blade is near the trailing edge of the adjacent blade, and is distant from the leading edge of the adjacent blade.

7. An impeller structure, comprising:

a hub, rotated about a rotation axis, having an outer surface;

a plurality of sub-blades radiantly extended from the outer surface of the hub, respectively;

a separation ring disposed on the end of the sub-blades;

a plurality of blades extended from the separation ring opposite to the sub-blades, wherein each of the blades has a windward surface and a leeward surface opposite to the windward surface, and each of the blades has a side edge, a connecting edge opposite to the side edge, a trailing edge, and a leading edge opposite to the trailing edge, wherein the side edge is distant from the separation ring, and the connecting edge is connected to the separation ring; and

a plurality of reinforcing ribs, annularly and separately disposed on the blades, located between the side edges and the connecting edges of the blades,

wherein an end of one of the reinforcing ribs is connected to the windward surface of one of the blades, and the other end of the one of the reinforcing ribs is connected to a leeward surface of an adjacent blade, and

wherein the end of the one of the reinforcing ribs is adjacent to the leading edge of the blade and is distant from the trailing edge of the blade, and the other end of the one of the reinforcing ribs is adjacent to a trailing edge of the adjacent blade and is distant from a leading edge of the adjacent blade.

8. The impeller structure as claimed in claim 7, wherein the width of each of the reinforcing ribs is smaller than half of a wing-tip chord length of each of the blades.

9. The impeller structure as claimed in claim 7, wherein the reinforcing rib is connected to the blade at an area from one-third to two-third of the blade 220.

10. The impeller structure as claimed in claim 7, wherein the reinforcing ribs are perpendicular to the blades, respectively.

11. The impeller structure as claimed in claim 7, wherein the cross section of each of the reinforcing ribs is rectangular, rectangular with rounded ends, an ellipse, a trapezoid, or wing shaped.

12. The impeller structure as claimed in claim 7, wherein the leading edge of the blade is near the trailing edge of the adjacent blade, and is distant from the leading edge of the adjacent blade.

13. The impeller structure as claimed in claim 7, wherein the length of each of the sub-blades is smaller than the length of each of the blades, and the number of the sub-blades is greater than the number of the blades.

14. A fan, comprising an impeller structure, the impeller structure comprising:

a hub, rotated about a rotation axis, having an outer surface;

a plurality of blades extended from the outer surface, wherein each of the blades has a windward surface and a leeward surface opposite to the windward surface, and each of the blades has a side edge, a connecting edge opposite to the side edge, a trailing edge, and a leading edge opposite to the trailing edge, wherein the side edge is distant from the hub, and the connecting edge is connected to the hub; and

a plurality of reinforcing ribs, annularly and separately disposed on the blades, located between the side edges and the connecting edges of the blades,

wherein an end of one of the reinforcing ribs is connected to the windward surface of one of the blades, and the other end of the one of the reinforcing ribs is connected to a leeward surface of an adjacent blade,

wherein the end of the one of the reinforcing ribs is adjacent to the leading edge of the blade and is distant from the trailing edge of the blade, and the other end of the one of the reinforcing ribs is adjacent to a trailing edge of the adjacent blade and is distant from a leading edge of the adjacent blade.

15. The fan as claimed in claim 14, wherein the width of each of the reinforcing ribs is smaller than half of a wing-tip chord length of each of the blades.

16. The fan as claimed in claim 14, wherein the reinforcing rib is connected to the blade at an area from one-third to two-third of the blade.

17. The fan as claimed in claim 14, wherein the reinforcing ribs are perpendicular to the blades, respectively.

18. The fan as claimed in claim 14, wherein the cross section of each of the reinforcing ribs is rectangular, rectangular with rounded ends, an ellipse, a trapezoid, or wing shaped.

19. The fan as claimed in claim 14, wherein the leading edge of the blade is near the trailing edge of the adjacent blade, and is distant from the leading edge of the adjacent blade.