# US 2019/0376523 A1 · Centrifugal fan

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- Number: US 2019/0376523 A1
- Document ID: US20190376523A1
- Status: Published application
- Kind: A1
- Application number: 16/546,474
- Filed: 2019-08-21
- Published: 2019-12-12
- Earliest claimed: 2015-10-23
- Assignees: MINEBEA MITSUMI Inc.
- Applicants: MINEBEA MITSUMI Inc.
- Inventors: Takuji YAMADA; Masaaki MATSUBARA; Seiya FUJIMOTO; Kiyohisa NARA
- Web page: https://patentgrep.com/patent/US20190376523A1

## CPC

- F04D 29/162: {of a centrifugal flow wheel}
- F04D 29/601: {specially adapted for elastic fluid pumps}
- F04D 25/06: the pump being electrically driven (F04D25/08 takes precedence)
- F04D 25/0613: {the electric motor being of the inside-out type, i.e. the rotor is arranged radially outside a central stator}
- F04D 25/0693: {Details or arrangements of the wiring}
- F04D 25/08: the working fluid being air, e.g. for ventilation
- F04D 29/281: {for fans or blowers}
- F04D 29/4226: {Fan casings}
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)

## Abstract

The application provides a centrifugal fan that can be easily positioned when it is installed in a device or apparatus, which can further improve positioning accuracy, and which can decrease noise, even if it is made thin. In the centrifugal fan in which an impeller is received inside a casing and air drawn in from a suction port formed on the casing by rotating the impeller is discharged from the casing to the outside of a blowing port, a circular protruded portion is formed on a peripheral edge of the suction port, and protrudes upwardly in a shaft direction from an upper surface of the casing.

## Claims

### Claim 1

A centrifugal fan comprising:
a casing formed by a lower casing and an upper casing having a suction port;
pillars interposed between the lower casing and the upper casing;
an impeller housed in the casing and having a circular shroud, a main plate,
and blades arranged between the circular shroud and the main plate; and a motor for rotating the impeller;
wherein a circular protruded portion for engaging with an object in which the centrifugal fan is installed is formed on a peripheral edge of the suction port, multiple concavities are formed on an upper surface of the upper casing and arranged outside the circular protruded portion,
wherein the circular protruded portion protrudes upwardly in a shaft direction from the upper surface of the upper casing, and
air sucked from the suction port by rotating the impeller is discharged from a blowing port formed between the upper casing and the lower casing.

### Claim 2 (depends on 1)

The centrifugal fan according to claim 1,
wherein the circular shroud has a circular protruded portion,
a circular groove is arranged on a lower surface of the circular protruded portion of the upper casing corresponding to the circular protruded portion of the circular shroud, and
a part of the circular protruded portion of the circular shroud is housed in the circular groove.

### Claim 3 (depends on 2)

The centrifugal fan according to claim 2,
wherein a labyrinth seal structure is formed between the circular groove and the circular protruded portion formed on the circular shroud.

### Claim 4 (depends on 2)

The centrifugal fan according to claim 2,
wherein radial ribs and circular ribs that connect the radial ribs are formed such that an individual concavity is formed in the radial ribs and the circular ribs.

### Claim 5 (depends on 4)

The centrifugal fan according to claim 4,
wherein the pillars are arranged outside of an outermost individual concavity.