Centrifugal fan and apparatus using the same
View Patent ↗A lateral plate and a main plate are provided inside a casing, and a plurality of blades are circularly arranged on this main plate. A plurality of asperities are formed from the front blade edge toward the rear blade edge on at least one of dorsal and ventral sides of each blade.
1. A centrifugal fan comprising:
a plurality of blades circularly arranged, wherein the plurality of blades are interposed between a ring-like lateral plate and a main plate, and integrated;
a casing including therein the plurality of blades, wherein the casing has a discharge outlet, and an inlet with an internal diameter equal to that of the plurality of blades circularly arranged; and
a motor with a rotation axis thereof connected to the main plate, wherein the motor is fixed to the casing,
wherein each of the plurality of blades has a plurality of asperities on one of the dorsal or ventral sides thereof,
wherein a side of the lateral plate of the plurality of blades is arranged at the inlet,
wherein the asperities are formed with a projection and a recess alternately repeated from a front edge toward a rear edge thereof in a cross section vertical to a rotation axis of the plurality of blades,
wherein the asperities extend in a direction parallel to the rotation axis of the plurality of blades, and
wherein the asperities extend an axial distance less than the axial length of the plurality of blades.
2. The centrifugal fan as claimed in claim 1 , wherein the main plate has a substantially truncated-cone-shaped throttle projecting toward the lateral plate.
3. The centrifugal fan as claimed in claim 1 , wherein an inside of the casing is formed spirally.
4. The centrifugal fan as claimed in claim 1 , wherein an internal diameter of the plurality of blades increases from the main plate toward the lateral plate.
5. The centrifugal fan as claimed in claim 4 , wherein an internal diameter of the plurality of blades increases linearly from the main plate toward the lateral plate.
6. The centrifugal fan as claimed in claim 4 , wherein a shape of the asperities is formed with arcs continuously repeated.
7. The centrifugal fan as claimed in claim 4 , wherein a recess of the asperities is triangle.
8. The centrifugal fan as claimed in claim 4 , wherein a projection of the asperities is triangle.
9. The centrifugal fan as claimed in claim 4 , wherein a shape of the asperities is formed with triangles continuously repeated.
10. The centrifugal fan as claimed in claim 4 , wherein a shape of the asperities is formed with quadrangles continuously repeated.
11. The centrifugal fan as claimed in claim 4 ,
wherein X, distance between a rotation center of the plurality of blades circularly arranged and a position at an internal diameter of the asperities, in a direction of a rotation axis, remains constant; and
wherein distance between the rotation center and a position at an external diameter of the asperities remains constant.
12. The centrifugal fan as claimed in claim 11 ,
wherein relationship among X which is the distance, D 1 which is an internal diameter of the plurality of blades circularly arranged, and D 2 which is an external diameter of the same, is to be D 1 <2X<D 1 +0.35(D 2 −D 1 ).
13. The centrifugal fan as claimed in claim 4 ,
wherein relationship among X which is distance from a rotation center of the plurality of blades circularly arranged to a position of the asperities at an internal diameter thereof, D 1 which is an internal diameter of the plurality of blades circularly arranged, and D 2 which is an external diameter of the same, is to be D 1 <2X<D 1 +0.35(D 2 −D 1 ).
14. The centrifugal fan as claimed in claim 4 ,
wherein a ratio between h which is depth of a recess of the asperities, and t which is board thickness of the plurality of blades, is to be 0.1<h/t<0.7;
wherein a ratio between f which is width of a recess of the asperities, and h which is the depth, is to be 0.5 h≦f≦2.5 h; and
wherein relation between Y which is an axial length of the asperities from the lateral plate in a direction of the main plate, and H which is the axial length of the plurality of blades, is to be 0.1<Y/H<1.0.
15. The centrifugal fan as claimed in claim 1 , wherein a recess of the asperities is arc-shaped.
16. The centrifugal fan as claimed in claim 1 , wherein a projection of the asperities is arc-shaped.
17. The centrifugal fan as claimed in claim 1 , wherein a shape of the asperities is formed with arcs continuously repeated.
18. The centrifugal fan as claimed claim 1 , wherein a recess of the asperities is triangle.
19. The centrifugal fan as claimed in claim 1 , wherein a projection of the asperities is triangle.
20. The centrifugal fan as claimed in claim 1 , wherein a shape of the asperities is formed with triangles continuously repeated.
21. The centrifugal fan as claimed in claim 1 , wherein a shape of the asperities is formed with quadrangles continuously repeated.
22. The centrifugal fan as claimed in claim 1 ,
wherein X, distance between a rotation center of the plurality of blades circularly arranged and a position at an internal diameter of the asperities, in a direction of a rotation axis, remains constant; and
wherein distance between the rotation center and a position at an external diameter of the asperities remains constant.
23. The centrifugal fan as claimed in claim 22 , wherein relationship among X which is the distance from a rotation center of the plurality of blades circularly arranged to a position of the asperities at an internal diameter thereof, D 1 which is an internal diameter of the plurality of blades circularly arranged, and D 2 which is an external diameter of the same, is to be D 1 <2X<D 1 +0.35(D 2 —D 1 ).
24. The centrifugal fan as claimed in claim 1 ,
wherein the centrifugal fan is included in one of an air conditioner, ventilating blower, air purifier, humidifier, and dehumidifier.
25. A centrifugal fan according to claim 1 , wherein the plurality of asperities are formed on most of the one of the dorsal or ventral sides of the plurality of blades.
26. A centrifugal fan according to claim 1 , wherein the inlet is a bellmouth inlet.
27. The centrifugal fan as claimed in claim 1 ,
wherein relationship among X which is distance from a rotation center of the plurality of blades circularly arranged to a position of the asperities at an internal diameter thereof, D 1 which is an internal diameter of the plurality of blades circularly arranged, and D 2 which is an external diameter of the same, is to be D 1 <2X<D 1 +0.35(D 2 −D 1 ).
28. The centrifugal fan as claimed in claim 1 ,
wherein a ratio between h which is depth of a recess of the asperities, and t which is board thickness of the plurality of blades, is to be 0.1<h/t<0.7;
wherein a ratio between f which is width of a recess of the asperities, and h which is the depth, is to be 0.5 h<f<2.5 h; and
wherein relation between Y which is an axial length of the asperities from the lateral plate in a direction of the main plate, and H which is the axial length of the plurality of blades, is to be 0.1<Y/H<1.0.