WO 2023/001597 PCT/EP2022/069119

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ELECTRICAL FAN

FIELD OF THE INVENTION

Embodiments of the present disclosure generally relate to an electrical fan.

BACKGROUND OF THE INVENTION

An electrical fan is a powered machine used to create airflow for some applications comprising climate control and personal thermal comfort, vehicle engine cooling systems, machinery cooling systems, ventilation, fume extraction, winnowing, removing dust, drying and providing a draft for a fire. An electrical fan typically comprises a rotating arrangement of blades. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing or case which may direct the airflow or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines.

In terms of the arrangement of the fan blades and the shaft of an electrical fan, the electrical fan may be divided into two types, one is the normal structure, and another is the reversed structure. In the normal structure, the shaft is fixedly arranged on a rotational center of the fan blades for example by molding. The shaft with the fan blades is rotatably arranged on a base via a bearing fixedly mounted in a bearing base on the base. In comparison with the normal structure, in the reversed structure, the fan blades are rotatably arranged on a shaft which is fixedly arranged on a base.

SUMMARY OF THE INVENTION

Embodiments of the present disclosure provide an electrical fan in a reversed structure.

In a first aspect, an electrical fan is provided. The electrical fan comprises a base; a shaft fixedly arranged on the base; a stator assembly fixedly arranged on the base and around the shaft, the stator assembly comprising a radially inward protrusion; and a fan blade assembly comprising: a bearing seat adapted to receive a bearing via which the fan blade assembly is rotatably arranged on the shaft; and a protrusion ring protruding radially outward from the bearing seat and arranged to be blocked by the radially inward protrusion in an axial direction during operation of the electrical fan.

With the radially inward protrusion and the protrusion ring formed on the bearing seat, the fan blade assembly would not fall off the shaft even if the electrical fan is in the dynamic status for example where the electrical fan is mounted on a mask which may move at any time with a wearer of the mask, which improves the stability of the electrical fan. Furthermore, this makes the application of the electrical fan wider. 2021P00385W001 WO 2023/001597 PCT/EP2022/069119

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In some embodiments, the at least one of the radially inward protrusion or the protrusion ring is elastic to allow the fan blade assembly to be installed in place. This arrangement can facilitate the installation of the fan blade assembly on the shaft.

In some embodiments, the radially inward protrusion comprises a plurality of sub protrusions evenly distributed in a circumferential direction and spaced a predetermined distance apart. With the sub-protrusions, the force required to elastically deform the radially inward protrusion can be reduced to thereby further facilitate the installation of the fan blade assembly. Furthermore, the thickness of the radially inward protrusion does not have to be compromised for easy deformation, which can ensure that the protrusion ring can always be blocked by the radially inward protrusion during the operation of the electrical fan.

In some embodiments, the radially inward protrusion is tapered radially inward. This arrangement can further facilitate the installation of the fan blade assembly on the shaft.

In some embodiments, at least a surface of the radially inward protrusion away from the base is inclined.

In some embodiments, a surface of the protrusion ring facing the base is inclined so that an axial thickness of the protrusion ring decreases radially outward. This arrangement can further facilitate the installation of the fan blade assembly on the shaft.

In some embodiments, the base comprises a stator seat arranged around the shaft, and wherein the stator assembly is mounted on the stator seat and comprises a coil seat wound by coils. In this way, the stator assembly can be fixedly arranged on the base in an easier way.

In some embodiments, the radially inward protrusion is formed on the coil seat. This arrangement can minimize changes to the structure of the electrical fan, to thereby reduce costs for improving the electrical fan.

In some embodiments, the fan blade assembly further comprises a plurality of fan blades adapted to provide airflow when the fan blade assembly is rotated; and a rotor body fixedly arranged around the bearing seat for the plurality of fan blades to be arranged thereon. This arrangement may facilitate the manufacturing of the fan blade assembly.

In some embodiments, the protrusion ring is integrally formed on an outer peripheral of the bearing seat. This arrangement can minimize changes to the structure of the electrical fan, to thereby reduce costs for improving the electrical fan.

In some embodiments, the fan blade assembly further comprises a plurality of magnets arranged on the rotor body and surrounding the coil seat to interact with magnetic fields generated by the energized coils to drive the fan blade assembly to rotate.

It is to be understood that the Summary is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the description below. 2021P00385W001 WO 2023/001597 PCT/EP2022/069119

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BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objectives, features and advantages of the present disclosure will become more apparent through more detailed depiction of example embodiments of the present disclosure in conjunction with the accompanying drawings, wherein in the example embodiments of the present disclosure, same reference numerals usually represent the same components.

FIG. 1 shows a side sectional view of an electrical fan with a normal structure in prior art;

FIG. 2 shows a side sectional view of an electrical fan with a reversed structure in prior

FIG. 3 shows a side sectional view of an electrical fan according to embodiments of the present disclosure; and

FIG. 4 shows an enlarged view of part A of the electrical fan as shown in FIG. 3.

Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.

DETAIFED DESCRIPTION OF THE EMBODIMENTS

The present disclosure will now be discussed with reference to several example embodiments. It is to be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the subject matter.

As used herein, the term “comprises” and its variants are to be read as open terms that mean “comprises, but is not limited to.” The term “based on” is to be read as “based at least in part on.” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment.” The term “another embodiment” is to be read as “at least one other embodiment.” The terms “first,” “second,” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be comprised below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.

Mechanically, an electrical fan comprises revolving vanes or blades used for producing airflow. Electrical fans produce airflow with high volume and low pressure (although higher than ambient pressure) when fan blades rotate. Typically, fan blades 104’ of an electrical fan with a normal structure are molded with a shaft 102’ fixedly arranged in a rotational center of a fan blade assembly. The shaft 102’ is then rotatably arranged on a base or a substrate via a bearing 105’ mounted in a bearing seat, as shown in FIG. 1.

In the normal structure of an electrical fan, subject to the needs of structural strength and stable rotation, etc., as shown in FIG. 1, the length D 1 of a portion of the shaft 102’ molded into a fan blade assembly and the length D2 of the shaft 102’ at the bottom of the bearing seat need to be larger than a predetermined threshold length. This results in a larger thickness of the electrical fan, which limits the use of the electrical fan in certain occasions and applications. 2021P00385W001 WO 2023/001597 PCT/EP2022/069119

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To at least make an electrical fan thinner, a reversed structure of the electrical fan is developed, as shown in FIG. 2. In comparison with the normal structure, the electrical fan 100’ with the reversed structure comprises a shaft 102’ fixedly arranged on a base 10G. That is, the fan blade assembly 104’ of the electrical fan 100’ is not molded with the shaft 102’. The fan blade assembly 104’ comprises a bearing seat 1044’ for receiving a bearing 1045’ via which the fan blade assembly 104’ is rotatably arranged on the shaft 102’.

With the electrical fan 100’ having the reversed structure, the lengths D1 and D2 as mentioned above are no longer needed. In this way, the electrical fan can be made thinner. As a result, the electric fan can be used in occasions and applications such as notepads, etc., with stricter requirements on thickness and space. In these occasions and applications, the electrical fan is usually in a stationary status where the electrical fan is typically stationary during operation.

In some applications for example where the electrical fan is used in a mask to facilitate the wearer’s breathing, the fan is usually in a dynamic status. For example, the wearer may walk or run while wearing the mask equipped with the electrical fan with the reversed structure. However, due to lack of limitation to the fan blade assembly, when the wearer walks or runs, there is a risk of the fan blade assembly shifting from a required position or even falling off the shaft, causing a failure of the electrical fan and possible harm to the wearer.

In order to at least partially address the above and other potential problems, embodiments of the present disclosure provide an electrical fan with the reversed structure. Now some example embodiments will be described with reference to FIGs. 3 and 4.

As shown in FIGs. 3 and 4, generally, the electrical fan 100 according to embodiments of the present disclosure comprises a base 101, a shaft 102, a stator assembly 103 and a fan blade assembly 104. The electrical fan 100 uses the reversed structure with the shaft 102 fixedly arranged on the base

101. The base 101 is a fixed part of the electrical fan 100. In some embodiments, the base 101 may be a part of a housing of the electrical fan 100 and comprise vents or openings for easy air flow. In some embodiments, besides the shaft 102 arranged thereon, the base 101 may further comprise a stator seat 1011 arranged around the shaft 102. The stator seat 1011 may be integrally formed with other parts of the base 101 for example by molding, etc., which can improve the structural strength of the base 101 and entire electrical fan 100. In some alternative embodiments, the stator seat 1011 and the other parts of the base 101 may also be separately formed and assembled together.

The stator assembly 103 may be mounted on the stator seat 1011 and around the shaft

102. The stator assembly 103 comprises a coil seat 1032 wound by coils 1033. The coils 1033 when energized would generate changing magnetic fields which interact with magnetic fields generated by a plurality of magnets 1046 arranged on the fan blade assembly 104 to thereby drive the fan blade assembly 104 to rotate. In this way, the fan blade assembly 104 provides airflow. The fan blade assembly 104 comprises a bearing seat 1044 for receiving a bearing 1045 via which the fan blade assembly 104 is rotatably arranged on the shaft 102. 2021P00385W001

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Besides the bearing seat 1044, in some embodiments, the fan blade assembly 104 further comprises a plurality of fan blades 1041 to provide airflow when the fan blade assembly 104 is rotated and a rotor body 1043. The rotor body 1043, also known as a hub, is fixedly arranged around the bearing seat 1044 and used for the plurality of fan blades 1041 to be arranged thereon. For example, in some embodiments, the rotor body 1043 and the bearing seat 1044 may be integrally formed, for example, by molding. The fan blades 1041 e.g., made of metallic material or any suitable material, are arranged on the rotor body 1043. In some alternative embodiments, the fan blades 1041 may also be integrally formed with the rotor body 1043 and the bearing seat 1044.

In comparison to the conventional solutions, to at least prevent the fan blade assembly 104 from falling off the shaft 102, the stator assembly 103 comprises a radially inward protrusion 1031 and the fan blade assembly 104 comprises a protrusion ring 1042 protruding radially outward from the bearing seat 1044. The protrusion ring 1042 is arranged to be blocked by the radially inward protrusion 1031 in an axial direction during operation of the electrical fan 100. In this way, the fan blade assembly 104 would not fall off the shaft 102 even if the electrical fan 100 is in the dynamic status, for example where the electrical fan 100 is mounted on a mask which may move at any time with the wearer of the mask. That is, the electrical fan 100 can be used in the dynamic status safely and reliably. This makes the application of the electrical fan 100 wider.

In some embodiments, the radially inward protrusion 1031 may be formed on the coil seat 1032, as shown in FIGs. 3 and 4. For example, a portion of the coil seat 1032 extending axially beyond the stator seat 1011 may protrude radially inward, i.e., towards the shaft 102 and beyond the stator seat 1011 , to integrally form the radially inward protrusion 1031. This arrangement may ensure the strength of the radially inward protrusion 1031 and the coil seat 1032. In some alternative embodiments, the radially inward protrusion 1031 may also be separately manufactured and mounted on the radially outer surface of the coil seat 1032. For example, in some alternative embodiments, the radially inward protrusion 1031 may also be an elastic ring to be mounted on the radially outer surface of the coil seat 1032 after the fan blade assembly 104 is installed on the shaft 102 in position. The elastic ring may radially extend beyond the stator seat 1011 to provide the block for the protrusion ring 1042. This arrangement can further reduce costs for improving the electrical fan 100.

It is to be understood that the above embodiments where the radially inward protrusion 1031 is formed or arranged on the coil seat 1032 are merely for illustrative purposes, without suggesting any limitation as to the scope of the present disclosure. Any other suitable arrangement or structure is also possible. For example, in some alternative embodiments, the radially inward protrusion 1031 may also be formed or arranged on the stator seat 1011. In this way, the manufacturing of the electrical fan 100 can be more flexible.

In some embodiments, the protrusion ring 1042 may be integrally formed on an outer peripheral of the bearing seat 1044, as shown in FIG. 4. This arrangement can minimize changes to the structure of the electrical fan 100, to thereby reduce costs for improving the electrical fan 100. In some 2021P00385W001 WO 2023/001597 PCT/EP2022/069119

6 alternative embodiments, the protrusion ring 1042 may also be an elastic ring to be mounted on the outer peripheral of the bearing seat 1044. Hereinafter, embodiments where the protrusion ring 1042 is integrally formed on the bearing seat 1044 and the radially inward protrusion 1031 is integrally formed on the coil seat 1032 will be mainly used as an example to describe the inventive concept of the present disclosure. It is to be understood that other arrangements are also similar, and will not be described separately in the following.

Furthermore, with the protrusion ring 1042 formed on the bearing seat 1044 and the radially inward protrusion 1031 formed on the coil seat 1032, when the fan blade assembly 104 is rotated, the airflow provided by the fan blade assembly 104 and a negative pressure formed in the stator seat 1011 would force the fan blade assembly 104 and the protrusion ring 1042 to axially move away from the radially inward protrusion 1031, to thereby prevent contact between the radially inward protrusion 1031 and the protrusion ring 1042 during operation of the electrical fan 100. In this way, the electrical fan 100 can be operated smoothly.

To facilitate the installation of the fan blade assembly 104 on the shaft 102, in some embodiments, the radially inward protrusion 1031 and/or the protrusion ring 1042 may be elastic. In other words, the radially inward protrusion 1031 and/or the protrusion ring 1042 may be deformable and may be restored to their original form after being deformed. In this way, when the fan blade assembly 104 is installed on the shaft 102, the radially inward protrusion 1031 and/or the protrusion ring 1042 may be deformed to allow the fan blade assembly 104 to be installed in place. After the fan blade assembly 104 is installed in place, the radially inward protrusion 1031 and/or the protrusion ring 1042 may return to their original shape, so that the protrusion ring 1042 can be blocked by the radially inward protrusion 1031.

In some embodiments, to ensure that the protrusion ring 1042 can always be blocked by the radially inward protrusion 1031 during the operation of the electrical fan 100 while facilitating the installation of the fan blade assembly 104, the radially inward protrusion 1031 may comprise a plurality of sub -protrusions. The plurality of sub-protrusions are evenly distributed in a circumferential direction and spaced a predetermined distance apart.

With the sub-protrusions, in comparison to the arrangements of the radially inward protrusion 1031 extending in the circumferential direction without interruptions, the force required to elastically deform the radially inward protrusion 1031 can be reduced to thereby further facilitate the installation of the fan blade assembly 104. Furthermore, the thickness of the radially inward protrusion 1031 does not have to be compromised for easy deformation, which can ensure that the protrusion ring 1042 can always be blocked by the radially inward protrusion 1031 during the operation of the electrical fan 100.

In some embodiments, the radially inward protrusion 1031 may be tapered radially inward. For example, in some embodiments, at least a surface of the radially inward protrusion 1031 away from the base 101 may be inclined to result in the tapered radially inward protrusion 1031. In this way, the fan blade assembly 104 can be installed on the shaft 102 in place more easily. 2021P00385W001 WO 2023/001597 PCT/EP2022/069119

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In some embodiments, a surface of the protrusion ring 1042 facing the base 101 is inclined so that the axial thickness of the protrusion ring 1042 decreases radially outward. In this way, the inclined surfaces of the protrusion ring 1042 and the radially inward protrusion 1031 may provide guidance when the fan blade assembly 104 is installed on the shaft 102, to thereby further facilitate the installation of the fan blade assembly 104.

It should be appreciated that the above detailed embodiments of the present disclosure are only for exemplifying or explaining principles of the present disclosure and do not limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvements, etc. without departing from the spirit and scope of the present disclosure shall be comprised in the scope of protection of the present disclosure. Meanwhile, appended claims of the present disclosure aim to cover all the variations and modifications falling under the scope and boundary of the claims or equivalents of the scope and boundary.