EP4352366A1

EP4352366A1 - Thin fan with a high ingress protection rating

Info

Publication number: EP4352366A1
Application number: EP22731613.0A
Authority: EP
Inventors: Wei Gu; Fu-Lung Lin; Haiyong Huang; Bing Li; Zhongchi LUO; Lijian TANG; Weizhong Chen
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2021-06-07
Filing date: 2022-06-02
Publication date: 2024-04-17
Also published as: CN117441063A; WO2022258464A1

Abstract

Embodiments of the disclosure relate to a fan comprising: a motor comprising a metal motor shell, a bottom wall of the metal motor shell comprising at least one through-hole adjacent to a central line of the bottom wall; a plastic fan blade component integrated with the metal motor shell and comprising: a fan blade support body formed on an outer surface of the bottom wall; and a protection ring formed inside the bottom wall, extending circumferentially around the central line; wherein the fan blade support body and the protection ring are integrated via the at least one through-hole.

Description

THIN FAN WITH A HIGH INGRESS PROTECTION RATING

FIELD OF THE INVENTION

This invention relates to a fan, and in particular, an ultra-thin fan with a dust, dirt or moisture resistant design.

BACKGROUND OF THE INVENTION

A fan is a well-known device, which produces airflow to actively remove heat, dirt or moisture from an environment, so that the environment can be maintained at its desired air condition. There are many different types of fans, among which an ultra-thin fan is of particular interest to users, as the ultra-thin fan can be accommodated in a limited space, while maintaining the capability of sufficiently removing heat, dirt or moisture from the space. Efforts are devoted to pushing the limits of miniaturization with the ultra-thin fan.

SUMMARY OF THE INVENTION

Embodiments of the invention aim to provide an improved fan (e.g., an improved ultra- thin fan), which may at least have a reduced overall thickness as well as a high IP (Ingress Protection) rating.

The invention is defined by the claims.

According to one aspect of the disclosure, there is provided a fan comprising: a motor comprising a metal motor shell, a bottom wall of the metal motor shell comprising at least one through-hole adjacent to a central line of the bottom wall; a plastic fan blade component integrated with the metal motor shell and comprising: a fan blade support body formed on an outer surface of the bottom wall; and a protection ring formed inside the bottom wall, extending circumferentially around the central line; wherein the fan blade support body and the protection ring are integrated via the at least one through-hole.

In accordance with the present fan, owing to the presence of the metal motor shell with a bottom wall, the overall thickness of an ultra-thin fan can be reduced. In the meantime, with the design of the at least one through-hole on the bottom wall, a protection ring can be easily formed and integrated with the plastic fan blade component for preventing moisture, dirt or dust from entering the bearing area of the motor. Thereby, a high IP rating can also be achieved.

In some embodiments, the plastic fan blade component may be an integrated component formed by molding on the metal motor shell. For example, the plastic fan blade component can be made by an injection molding process. With this process, the fan blade support body as well as the protection ring may be molded at the same time. Also, the molded fan blade support body may cover the whole area of the outer surface of the bottom wall. In this way, the mechanical strength of the fan can be improved.

In some embodiments, the motor further comprises a shaft fixed on the bottom wall and extending along the central line. For example, the shaft may be soldered or welded onto the bottom wall of the metal motor shell. In this way, the overall thickness of the motor can be reduced. Also, the assembly for the motor can be simplified.

In some embodiments, the plastic fan blade component further comprises a plurality of plastic fan blades extending radially from the fan blade support body. The plurality of plastic fan blades may help to expel the dirt, heat, dust, or moisture from a space.

In some embodiments, a thickness of the bottom wall may be in the range from 0.2 mm to 0.5 mm. The material for the bottom wall may be selected from a rigid metal (e.g., a sheet steel). The selected thickness of the bottom wall in combination with the fan blade support body may be sufficient to support the plurality of fan blades during the operation.

In some embodiments, a height of the protection ring from the inner surface of the bottom wall to a tip of the protection ring may be in the range of 0.6 mm-0.8 mm. This range of height may be sufficient to create a minimum gap between a tip of the protection ring and the proximal end of a bearing holder, which is advantageous to block the dirt, heat, dust, or moisture from entering the bearing area.

In some embodiments, the at least one through-hole comprises a plurality of holes symmetrically distributed with respect to the shaft. In this way, the protecting ring may be formed more uniformly and easily around the shaft.

In some embodiments, the metal motor shell further comprises a side wall extending from the bottom wall, and the motor further comprises a plurality of magnet poles formed on the inner surface of the side wall. The plurality of magnet poles can be formed with a plurality of permanent magnets or a single magnet component in a way such that each magnetic pole faces the corresponding tip of the stator core. During operation, the interaction between the rotor magnetic field and the stator alternating magnetic field can cause the rotor as well as the plurality of fan blades to rotate.

In some embodiments, the motor further includes: a stator arranged within the metal motor shell; a bearing holder arranged within the center of the stator and delimiting a bearing area; and a bearing mounted within the bearing area; wherein the shaft is fixedly connected with the bearing. In this way, a compact design of the motor is provided.

In some embodiments, a gap between a tip of the protection ring and the proximal end of bearing holder may be below 0.5 mm. With this limited gap, moisture, dirt or dust could be prevented from entering the bearing area during operation. In some embodiments, an outer diameter of the fan may be in the range from 1.2 cm to 2 cm. In some embodiments, a thickness of the fan is below 1 cm. By defining the dimension of the outer diameter and the overall thickness of the fan, an ultra-thin & ultra-small fan is provided.

In some embodiments, the motor may be a brushless motor, e.g., a DC brushless motor.

In some other embodiments, the motor may be a brushed motor.

According to another aspect of the disclosure, a device is provided, comprising any fan in the first aspect. As an exemplary example, the device may be a face mask.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, similar/same reference signs throughout different views generally represent similar/same parts. Drawings are not necessarily to scale. Rather, emphasis is placed upon the illustration of the principles of the present invention. In these drawings:

Fig. 1 is a cross-sectional view of a first conventional fan.

Fig. 2 is a cross-sectional view of a second conventional ultra-thin fan.

Fig. 3 is a cross-sectional view of a fan according to one embodiment of the disclosure. Fig. 4 is a cross-sectional view of a metal motor shell of the fan according to one embodiment of the disclosure.

Fig. 5 is a perspective view of a metal motor shell of the fan according to one embodiment of the disclosure.

Fig. 6 is a perspective view of a metal motor shell integrated with a plastic fan blade component according to one embodiment of the disclosure.

Fig. 7 shows a face mask incorporating the fan according to one embodiment of the disclosure.

DETAIFED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the disclosure will be described in more detail with reference to the drawings. Although the drawings illustrate some embodiments of the disclosure, it should be appreciated that the disclosure can be implemented in various manners and should not be interpreted as being limited to the embodiments explained herein. On the contrary, the embodiments are provided to understand the disclosure in a more thorough and complete way. It should be appreciated that drawings and embodiments of the disclosure are only for exemplary purposes rather than restricting the protection scope of the disclosure.

In the descriptions of the embodiments of the disclosure, the term “includes” and its variants are to be read as open-ended terms that mean “includes, but is not limited to.” The term “based on” is to be read as “based at least in part on.” The terms “one embodiment” and “this embodiment” are to be read as “at least one embodiment.” The following text also can comprise other explicit and implicit definitions.

As stated above, it is of particular interest to provide an ultra-thin fan, which has a reduced overall thickness as well as a high IP rating.

Fig. 1 illustrates a first conventional fan. As illustrated in Fig. 1, the first conventional fan G comprises a motor 2’ and a plastic fan blade component 20’, which is molded on the motor 2’. The motor 2’ comprises a metal motor shell 3’, a plurality of magnets 4’ and a stator 5’, wherein the stator 5’ is arranged within the metal motor shell 3’, and the plurality of magnets 4’ are fixed on a side wall of the metal motor shell 3’. The metal motor shell 3’ in combination with the plurality of magnets 4’ can serve as an outer rotor.

The plastic fan blade component 20’ includes a fan blade support body 2G formed in a barrel shape and a plurality of fan blades 22’ extending radially from the fan blade support body 2G. The metal motor shell 3 is of an annular shape, i.e., with a side wall and almost no bottom wall. During the manufacturing process, the plastic fan blade component 20’ is at least over-molded on the side wall of the metal motor shell 3, with the fan blade support body 2G substantially covering the virtual bottom wall of the metal motor shell 3 ’ .

The motor 2’ further comprises a rotary shaft 7’ integrated with the plastic fan blade component 20’, and a bearing 8’ contained in a bearing holder 1 G. The bearing holder 1 G is arranged in the center of stator 5’ and delimits a bearing area. The rotary shaft 7’ is mounted within the bearing 8’. During operation, the interaction between the rotor magnetic field and the stator alternating magnetic field can cause the rotor as well as the plurality of fan blades to rotate.

In order to prevent moisture, dust or dirt from entering the bearing 8’, the plastic fan blade component 20’ is provided with a protection ring 23’ formed on the inner surface of the fan blade support body 2G, adjacent to a bearing holder 1 G, and extending circumferentially around the rotary shaft 7’. A gap can be formed between a tip of the protection ring 23’ and a proximal end of the bearing holder 1 G. During operation of the fan G, a gas pressure may be established within the bearing area, a sufficiently small gap can prevent moisture, dust or dirt from entering the bearing area due to the gas pressure. Typically, the dimension of the gap can be 0.5 mm or less.

During a molding process, the fan blade support body 2G needs to be molded with a sufficient thickness, such that one end of the rotary shaft 7’ can be embedded within the fan blade support body 2 G, and the fan blade support body 21 ’ can provide a sufficient strength to support the rotation of the plurality of fan blades 22’. However, the sufficient thickness required for plastic fan blade component 20’ may adversely add to the overall thickness of the fan G.

Fig. 2 illustrates a second conventional ultra-thin fan 1”, the thickness of which is reduced as compared to the first conventional fan 1 ’ . The second conventional ultra-thin fan 1” comprises a metal motor shell 3” with a bottom wall 31” and an annular side wall 32” . A plurality of magnets 4” are attached to a first side of the annular side wall 32”. A plastic fan blade component 20” is molded merely on a second side of the annular side wall 32”and extends radially from the second side. The metal motor shell 3” in combination with the plurality of magnets 4” can serve as an outer rotor.

The metal motor shell 3” is made of a single piece of metal. A rotary shaft 7” is soldered in the center of the inner surface of bottom wall 31 ” of the metal motor shell 3 ” .

The second conventional ultra-thin fan 1” further comprises a stator 5” and a bearing 8” contained in a bearing holder 11”. The bearing holder 11 ” is arranged in the center of the stator 5 ’ ’ and delimits a bearing area. The rotary shaft 7” is mounted within the bearing 8”.

Due to the fact that there is no plastic component molded on this thin bottom wall 31 ” of the metal motor shell 3 ” , and the rotary shaft 7” is directly soldered onto the bottom wall 31 ” , the thickness of fan 1” can be reduced, as compared to the fan G of Fig. 1.

However, the problems with the fan 1 ” he in that: it is not convenient to arrange a protection ring on the inner surface of the thin metal bottom wall 31 ” for preventing dirt, dust or moisture from entering into the bearing area, and the mechanical strength of the thin bottom wall 31” might not have sufficient mechanical strength to support the plastic fan blade component 20” .

In view of the above two conventional ultra-thin fans illustrated in Figs. 1 and 2, the purpose of the disclosure is to provide an improved fan, especially an ultra-thin fan, which may have a reduced overall thickness for the fan as well as a high IP rating.

Fig. 3 shows a cross-sectional view of a fan in accordance with one embodiment of the disclosure.

As illustrated in Fig. 3, the fan 1 comprises a motor 2 and a plastic fan blade component 20, which is molded on the motor 2. In principle, the fan can be of any size. In particular, the fan 1 can be an ultra-thin fan 1, e.g., having a thickness less than 2 cm, 1 cm, or 0.5 cm. The fan 1 may also be an ultra-small fan with the outer diameter of the fan in the range from 1.2 cm to 2 cm.

The motor 2 comprises a metal motor shell 3, a plurality of magnet poles 4 and a stator 6. In some embodiments, the motor 2 may be a DC brushless motor. However, other types of motors are also possible, e.g., a brushed DC motor.

Typically, the metal motor shell 3 is barrel shaped. The stator 6 can be housed within the metal motor shell 3. The stator 6 comprises a stator core 9 and armature windings 10 wound around the stator core 9. In some embodiments, the stator core 9 may be made from magnetic conductive material. For example, a silicon steel lamination may be formed as the stator core 9.

The motor 2 may further comprise a bearing holder 11 arranged within the center of the stator core 9 and delimiting a bearing area. A bearing 8 (e.g., a ball bearing) may be housed within the bearing holder 11 for fitting a rotary shaft 7. The metal motor shell 3 comprises a bottom wall 31 and a side wall 32 extending from the bottom wall 31. The plurality of magnets poles 4 may be formed by a plurality of permanent magnets or a single magnet component fixed onto an inner surface of the sidewall 32 of the metal motor shell 3. In some embodiments, the plurality of permanent magnets or a single magnet component may be welded, soldered or glued to the inner surface of the sidewall 32. The metal motor shell 3 in combination with a plurality of magnet poles 4 may serve as an outer rotor 5. During operation, when the armature windings 10 are energized, the interaction between the rotor magnetic field and the stator alternating magnetic field may cause the outer rotor 5 (i.e., including the metal motor shell 3 and the plurality of magnet poles 4) as well as the plastic fan blade component 20 to rotate.

Figs. 4 and 5 show a cross sectional view and a perspective view of the metal motor shell 3, respectively. As can be seen from Figs. 4 and 5, the bottom wall 31 is particularly provided with at least one through-hole 33. The at least one through-hole 33 is arranged adjacent to the central line 15 of the bottom wall 31. It will be understood that the at least one through-hole 33 is arranged to facilitate the manufacturing of the protection ring 23, as will be described below.

In some embodiments, the at least one through-hole 33 comprises a plurality of through- holes distributed on the bottom wall 31 around the central line 15. As an exemplary example, four through-holes 33 may be distributed on the bottom wall 31. However, other numbers of the plurality of through-holes are possible. In addition, at least one through-hole 33 may or may not be evenly or symmetrically distributed on the bottom wall 31 with respect to the shaft 7.

The shaft 7 may be fixed onto the inner surface of the bottom wall 31 and extends along the central line 15. In some embodiments, the shaft 7 may be welded or soldered to the inner surface of the bottom wall 31.

Referring to Figs. 3 and 6, a plastic fan blade component 20 includes a fan blade support body 21, a plurality of fan blades 22 and a protection ring 23. The plastic fan blade support body 21 is formed on the outer surface of the metal motor wall 3. The plurality of fan blades 22 extend radially and outwardly from the fan blade support body 21. The protection ring 23 is integrated with the fan blade support body 21 via the at least one through hole 33 and surrounds the shaft 7. In some embodiments, the plastic fan blade component 20 is an integrated component formed by over-molding on the metal motor shell 3, e.g., through an injection molding process. During the molding process, the molding material under pressure (e.g., injection pressure) may flow through the at least one through-hole 33 and form the protection ring 23. In this way, the fan blade support body 21, the plurality of fan blades 22 and the protection ring 23 can be manufactured at the same time.

The protection ring 33 may be formed with a height H of from the inner surface of the bottom wall 31 to a tip of the protection ring 22. In some embodiments, the protection ring 33 may extend vertically or obliquely with respect to the bottom wall 31 towards the stator 6. In some embodiments, the protection ring 22 may be formed such that the tip of the protection ring 22 may be positioned in a peripheral region of the bearing holder 11, adjacent to a proximal end of the bearing holder 11, but not in contact with bearing holder. In some embodiments, the height H may be in the range of 0.6 mm to 0.8 mm.

The protrusion of the protection ring 22 towards the stator 6 or the bearing holder 11 defines a gap G between the tip of the protection ring 22 and the proximal end of the bearing holder 11. The gap G may be measured as a minimum distance between the tip of the protection ring 22 and the proximal end of the bearing holder 11. It should be appreciated that a sufficiently small gap G may prevent moisture, dust or dirt from entering into the bearing area during operation of the fan. As an example, a sufficiently small gap G may be below 0.5 mm.

It should be appreciated that due to the presence of the metal bottom wall 31 and the shaft 7 being soldered or welded to the metal bottom wall 33, the fan blade support body 21 need not to be thick, the overall thickness of the fan 1 can thus be reduced, as compared to the first conventional fan 1 ’ .

As compared to the second conventional fan 1”, although the overall thickness of the fan 1 might slightly increase, the presence of the protection ring 23 could improve the IP (Ingress Protection) rating, thereby prolonging the lifespan of the fan 1. Further, the plastic fan blade component 20 is over molded on the thin metal shell 3 by an injection molding process, the mechanical strength for supporting the plurality of fan blades 23 can also be enhanced.

The present fan may be incorporated into any device for different purposes, or can function as a stand-alone device. As an example, Fig. 7 illustrates a face mask incorporating the present fan. It should be appreciated that when the face mask 100 is worn by a user, an enclosed space with high humidity is created by the face mask. With the present fan integrated on the face mask, the moisture, dirt and dust (if any) within this enclosed space can be expelled, improving the air condition within the enclosed space. Also, the present fan has a high IP rating, the presence of the moisture, dirt or dust in the environment may not significantly affect the lifespan of the fan.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A fan ( 1) comprising: a motor (2) comprising a metal motor shell (3), a bottom wall (31) of the metal motor shell (3) comprising at least one through-hole (33) adjacent to a central line (15) of the bottom wall (31); a plastic fan blade component (20) integrated with the metal motor shell (3) and comprising: a fan blade support body (21) formed on an outer surface of the bottom wall

(31); and a protection ring (22) formed inside the bottom wall (31) and extending circumferentially around the central line (15); wherein the fan blade support body (21) and the protection ring (22) are integrated via the at least one through-hole (33).

2. The fan (1) of claim 1, wherein the plastic fan blade component (20) is an integrated component formed by molding on the metal motor shell (3).

3. The fan (1) of any of claims 1-2, wherein the motor (2) further comprises a shaft (7) fixed on the bottom wall (31) and extending along the central line (25).

4. The fan (1) of any of claims 1-3, wherein the plastic fan blade component (20) further comprises a plurality of plastic fan blades (23) extending radially from the fan blade support body (21).

5. The fan (1) of any of claims 1-4, wherein a thickness of the bottom wall (31) is in the range from 0.2 mm to 0.5 mm.

6. The fan (1) of any of claims 1-5, wherein a height (H) of the protection ring (22) from the inner surface of the bottom wall (31) to a tip of the protection ring (22) is in the range of 0.6 mm-0.8 mm.

7. The fan (1) of any of claims 1-6, wherein the at least one through-hole (33) comprises a plurality of holes (33) symmetrically distributed with respect to the shaft (7).

8. The fan (1) of any of claims 1-7, wherein the metal motor shell (3) further comprises a side wall (32) extending from the bottom wall (31), and the motor (2) further comprises a plurality of magnet poles (4) formed on the inner surface of the side wall (32).

9. The fan (1) of any of claims 1-8, wherein the motor (2) further includes: a stator (6) arranged within the metal motor shell (3); a bearing holder (11) arranged within the center of the stator (6) and delimiting a bearing area; and a bearing (8) mounted within the bearing area; wherein the shaft (7) is fixedly connected with the bearing (8).

10. The fan (1) of claim 9, wherein a gap (G) between a tip of the protection ring (22) and a proximal end of the bearing holder (11) is below 0.5 mm.

11. The fan (1) of any of claims 1-10, wherein an outer diameter of the fan (1) is in the range from 1.2 cm to 2 cm.

12. The fan (1) of any of claims 1-11, wherein a thickness of the fan (1) is below 1 cm.

13. The fan (1) of any of claims 1-12, wherein the motor (2) is a DC brushless motor.

14. A device comprising the fan (1) of any one of claims 1-13.

15. The device of claim 14, wherein the device is a face mask (100).