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US 5,964,576 AGranted
Impeller of centrifugal fan
AssigneeJapan Servo Co., Ltd.
InventorsHideki Fujita, Naoya Ito, Masahiro Mimura
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AssigneeJapan Servo Co., Ltd.
InventorsHideki Fujita, Naoya Ito, Masahiro Mimura
Estimating the term…
An impeller of a centrifugal fan having fifty or more blades of not larger than 250 mm in outer diameter which has a casing and a multi-blade impeller rotatably supported in the casing, wherein a centrifugal force is applied on air entered into an inlet formed on the casing when the impeller is rotated, and an air of high pressure is taken out through an outlet formed on a portion of the casing. An outer peripheral surface of the impeller is inclined or curved so as to have an inlet side large diameter portion and a blade holding base side small diameter portion, or is stepped so as to have an inlet side cylindrical outer peripheral surface of large diameter and a blade holding base side cylindrical outer peripheral surface of small diameter connected to the inlet side cylindrical outer peripheral surface. The inlet side cylindrical outer peripheral surface and the blade holding base side cylindrical outer peripheral surface are substantially the same height.
In an impeller of a centrifugal fan having a casing and a multi-blade impeller rotatably supported in said casing, said impeller being of fifty or more blades of not larger than 250 mm in outer diameter, wherein, when sad impeller is rotated, a centrifugal force is applied on air entered into an inlet formed on said casing and air of high pressure is taken out through an outlet formed on a portion of said casing, the improvement characterized in that an outer peripheral surface of the impeller has 1) an inlet side cylindrical outer peripheral surface which is of a large diameter, 2) a blade holding base outer peripheral surface which is of a smaller diameter than said cylindrical outer peripheral surface, and 3) an inclined arcuate surface which is connected to the cylindrical outer peripheral surface and which gradually tapers in diameter toward said blade holding base outer peripheral surface, and wherein said cylindrical outer peripheral surface and said inclined arcuate surface are substantially the same height.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
For fans or blowers: the leading edge of each vane being substantially parallel to the rotation axis
Non-positive-displacement pumps
Term ended 21 Jul 2017 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention relates to an impeller of a centrifugal fan, and more particularly to an improvement of a multi-blade impeller for use in a noiseless centrifugal fan.
2. Description of the Prior Art
FIG. 1 is a perspective view of a multi-blade impeller of the present invention;
FIG. 2 is a vertically sectional side view of the impeller of FIG. 1;
FIG. 3 is a perspective view of a multi-blade impeller of another embodiment of the present invention;
A first embodiment of the present invention will be explained with reference to FIGS. 1 and 2.
FIG. 1 shows a perspective view of a multi-blade impeller 1 of the present invention and FIG. 2 shows a vertically sectional front view thereof.
The multi-blade impeller 1 of the present invention shown in FIGS. 1 and 2 has fifty or more blades of an outer diameter of not larger than 250 mm, and is used for a small size centrifugal fan.