Impeller and axial fan
AssigneeNidec Corporation
InventorsHideyuki Takemoto, Kazuhiro Inouchi
Life of this patent
Estimating the term…
Abstract
An impeller includes Z blades, where Z is an integer equal to 5 or more, arranged in a circumferential direction of the impeller and extending radially, pitch angles between adjacent blades being all different. In terms of an arbitrary pitch angle θ, when a pitch angle α1 adjacent to the pitch angle θ, and a pitch angle α2 adjacent to the pitch angle θ, different from the pitch angle α1, satisfy a relation, α1<α2, a pitch angle β1 different from the pitch angle θ adjacent to the pitch angle α1 and a pitch angle β2 adjacent to the pitch angle β2, different from the pitch angle θ, satisfy a relation, β2<β1.
Claims4
An impeller comprising:
- Z blades disposed in a circumferential direction of the impeller and extending radially, where Z is an integer equal to 5 or more;
- and
- pitch angles between the corresponding blades adjacent to each other being all different;
- wherein in terms of an arbitrary pitch angle θ, when a pitch angle α1 adjacent to the pitch angle θ, and a pitch angle α2 adjacent to the pitch angle θ, different from the pitch angle α1, satisfy a relation, α1<α2, a pitch angle ⊖1 different from the pitch angle θadjacent to the pitch angle α1 and a pitch angle β2 adjacent to the pitch angle α2, different from the pitch angle θ, satisfy a relation, β2<β1;
- wherein an n-th pitch angle satisfies an expression below, where n is an integer from 1 to Z, and a displacement ratio A has an absolute value of 0 or an irreducible fraction less than 1;
- Pitch
-
- (
- n
- )
- =
- 360
- Z
- ·
- [
- 1
- +
- Δ
- ·
- SIGN
-
- (
- n
- )
- ]
- where Z is a number of the blades;
- A is a displacement ratio;
- and
- SIGN(n) is a polarity of the displacement ratio A and is represented by:
- SIGN
-
- (
- n
- )
- =
- SIGN
-
- e
-
- (
- n
- )
- ·
- EVEN
-
- (
- Z
- )
- +
- SIGN
-
- o
-
- (
- n
- )
- ·
- ODD
-
- (
- Z
- )
-
- SIGN
-
- e
-
- (
- n
- )
- =
- cos
-
- (
- π
- ·
- (
- ABS
-
- (
- n
- -
- Z
- 2
- -
- 0.5
- )
- +
- 0.5
- )
- )
- SIGN
-
- o
-
- (
- n
- )
- =
- cos
-
- (
- π
- ·
- (
- n
- -
- Z
- 2
- -
- 0.5
- )
- )
- EVEN
-
- (
- Z
- )
- =
- (
- 1
- -
- mod
-
- (
- Z
- ,
- 2
- )
- )
- ODD
-
- (
- Z
- )
- =
- mod
-
- (
- Z
- ,
- 2
- )
- .
Dependencies are inferred from the claim text.