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US 7,255,533 B2Granted
Centrifugal fan
AssigneeNidec Corporation
InventorShinji Takemoto
Life of this patent
Estimating the term…
Abstract
It is possible to keep a diameter of an impeller and a cross sectional area of an air channel as large as possible while reducing a size of a centrifugal fan in a direction perpendicular to an axis. Thereby, it is possible to acquire characteristics of a high air volume and a high static pressure without lowering the efficiency. In the centrifugal fan, when the radial gap of the cross section in an air channel 10b is gradually enlarged from a clapper portion 10c toward an outlet 10d except for a specific region 10h, the cross inner sectional area of an air channel 10b is gradually enlarged from the clapper portion 10c toward the outlet 10d.
Claims6
A centrifugal fan for use in an electric device comprising:
- a motor including a static part and a rotational part rotating around a rotational axis;
- an impeller having a tubular-shaped outline that is mounted on a radially outer circumferential part of the rotational part;
- and
- a casing housing the impeller and the motor, wherein the casing includes:
- an upper plate and a lower plate which are located in parallel and opposing each other in axial direction;
- a peripheral wall portion formed at a radially outer circumference of the casing, wherein a curvature radius of the peripheral wall portion with respect to the rotational axis is gradually enlarged;
- and
- a blowing opening formed by the opposite ends of the peripheral wall portion and ends of the upper plate and lower plate;
- wherein an air channel is formed within a space enclosed by the upper plate and the lower plate, a radial outer circumference of the impeller and an inner circumferential surface of the peripheral wall portion of the casing, wherein a radial gap is defined as a distance from the radial outer circumference of the impeller to an inner circumferential surface of the peripheral wall portion and the radial gap is gradually enlarged along a rotational direction of the impeller except for at least one specific region provided at the peripheral wall portion of the casing, while the radial gap is kept constant or gradually reduced in the specific region, wherein an air channel enlarged part is located at a vicinity of the specific region, wherein an axial gap between the upper plate and the lower plate at the air channel enlarged portion is enlarged along a rotational direction of the impeller, and wherein a cross sectional area of the air channel cut by a plane passing through the rotational axis is kept constant or is gradually enlarged along the rotational direction of the impeller.
6 more elements
A centrifugal fan for use in an electric device comprising:
- a motor including a static part and a rotational part rotating around a rotational axis;
- an impeller having a tubular-shaped outline that is mounted on a radially outer circumferential part of the rotational part;
- and
- a casing housing the impeller and the motor, wherein the casing includes:
- an upper plate and a lower plate which are located in parallel and opposing each other in axial direction;
- a peripheral wall portion formed at a radially outer circumference of the casing, wherein a curvature radius of the peripheral wall portion with respect to the rotational axis is gradually enlarged;
- and
- a blowing opening formed by the opposite ends of the peripheral wall portion and ends of the upper and lower plates;
- wherein an air channel is formed within a space enclosed by the upper and the lower plates, a radial outer circumference of the impeller and an inner circumferential surface of the peripheral wall portion of the casing, wherein a radial gap is defined as a distance from the radial outer circumference of the impeller to an inner circumferential surface of the peripheral wall portion and the radial gap is gradually enlarged along a rotational direction of the impeller except for at least one specific region provided at therein while the radial gap is kept constant or gradually reduced in the specific region, wherein an air channel enlarged part is located at a vicinity of the specific region, wherein a radial gap between the radial outer circumference of the impeller and the inner circumferential side surface of the peripheral wall of the casing is enlarged along a rotational direction of the impeller, and wherein a cross sectional area of the air channel cut by a plane passing through the rotational axis is kept constant or is gradually enlarged along the rotational direction of the impeller.
6 more elements
Dependencies are inferred from the claim text.