Patent ID: 12199486

REFERENCE NUMBERS IN THE DRAWINGS ARE DESCRIBED AS BELOW

1—stator;11—stator outer periphery;111—stator unit;1111—insulating wire frame;112—semi-circular hole;113—connecting post;12—stator tooth;121—circular arc structure;13—winding group coil;13A—lead;13B—wiring end of winding group coil;131—first coil;132—second coil;133—third coil;134—fourth coil;135—fifth coil;136—sixth coil;14—stator groove;141—opening of stator groove;15—wire clamping portion;16—jumper;2—rotor;3—axial diffuser;31—outer cylinder;32—main body;33—diffuser vane;34—diffusion air passage;35—central shaft hole;36—positioning post;37—connecting hole;4—air hood;41—air inlet;42—second annular protrusion;5—impeller;6—bearing;7—circuit board;8—annular gridless channel;9—impeller chamber; and10—motor shaft.

DETAILED DESCRIPTION

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below in conjunction with the specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present disclosure. In addition, in the following description, descriptions of common structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present disclosure.

Schematic diagrams of layer structures according to the embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, in which, for the purpose of clarity, some details are exaggerated, and some details are probably omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary, and may vary in practice due to manufacturing tolerances or technical limitations, and those skilled in the art can additionally design regions/layers of different shapes, sizes and relative positions as required.

Obviously, the described embodiments are some, but not all, embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

In the descriptions of the present disclosure, it should be noted that the terms “first”, “second” and “third” are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance.

In addition, the technical features involved in different embodiments of the present disclosure described below can be combined with each other as long as they do not conflict.

FIG.1ais a schematic structural diagram of a stator according to an embodiment of the present disclosure.FIG.1bis a side view of the stator shown inFIG.1a.FIG.1cis a perspective view of the stator shown inFIG.1b.

As shown inFIGS.1ato1c, the stator1includes an annular stator outer periphery11, stator teeth12and winding group coils13sleeving the stator teeth12.

A plurality of stator teeth distributed uniformly is connected to the inner side of the stator outer periphery11in the circumferential direction.

The stator teeth12are provided along the radial direction of the stator outer periphery11, and the winding group coil sleeves each of the stator teeth.

Each winding group coil13is correspondingly provided with one insulating wire frame1111, and each insulating wire frame1111is provided along the axial direction of the stator outer periphery11.

The insulating wire frame1111is provided with a first lead groove. The first lead groove is configured to lead out one end of the winding group coil to enable it to be connected to the winding group coil of the same phase around the outside of the stator outer periphery11in the circumferential direction.

The depths of the first lead grooves of the insulating wire frames1111corresponding to the winding group coils of the same phase are the same, and the depths of the first lead grooves of the insulating wire frames1111corresponding to the winding group coils of different phases are different, such that lines of different phases are staggered in a height direction outside the stator outer periphery11in the circumferential direction. In this way, the lines of all phases of the stator may be arranged in order, and the stator is prevented from the risk of conduction caused by interlacing, and hence is prolonged in service life and improved in security.

One winding group coils13only sleeves one stator tooth12. In other words, in the present disclosure, the span of the winding group coils is 1. Since the span of the winding group coils is 1, the production efficiency can be improved. Since the coil is tied to one tooth, the rigidity of both the coil and an iron core can be improved, and the noise can be reduced.

It can be understood that in some prior art, when a stator is assembled with a coil of which the span is greater than 1, it is necessary to prepare a winding group coil according to a predetermined number of turns, and then embed the winding group coil into a stator groove, instead of directly sleeving the stator teeth by the coil. For example, with regard to a coil with a span of 2, two stator grooves are spanned between two ends of the coil. Generally, a rotor of a motor is a magnet having two poles and is located in a stator outer periphery, and the rotor is of a columnar structure, with the S pole and the N pole being semi-cylindrical. After analysis, the magnetic field direction of the rotor of the motor is in the circumferential direction of the stator outer periphery, i.e., the winding group coil in the axial direction of the stator outer periphery is active, while the winding group coil perpendicular to the axial direction of the stator outer periphery is inactive. Therefore, the coil with a span greater than 1 strides over many stator grooves because the coil perpendicular to the axial direction is relatively long, which may cause relatively long inactive copper wires, resulting in waste of the copper wires, high resistance, high copper loss, and relatively low efficiency.

After a great deal of research, it is determined that although a winding group coil with a span of 1 has a low winding coefficient (i.e., a torque output by the coil at the same current is relatively small), since the span is 1, i.e., one winding group coil is only wound around one stator tooth, the winding group coil may have short inactive copper wires, the copper wires are low in copper loss, and the efficiency is high. Although the coil with the span greater than 1 has a high winding coefficient, long inactive copper wires, high resistance and high copper loss may be caused because it is necessary to stride over multiple stator teeth and stator grooves, and the high copper loss may lead to little difference between the rotating efficiency of the stator and the efficiency of the coil with the span of 1 according to the present disclosure. However, according to the present disclosure, since the span of the coil is 1, the use of connection wires is reduced, the consumption of copper is low, and the coil can be tied to the stator teeth to improve the rigidity of the stator teeth. In this way, the production efficiency and the use efficiency of the stator are both improved.

In an embodiment, the number of the stator teeth of the stator is an even number.

In this embodiment, the stator outer periphery is connected to an even number of stator teeth distributed uniformly, and the number of the stator grooves equals the number of the stator teeth, i.e., there are also an even number of stator grooves, such that an unbalanced radial magnetic pull caused when the stator rotates, electromagnetic vibration and noise of the motor in use can be reduced.

FIG.2ais a schematic structural diagram of a chain-connected stator unit according to an embodiment of the present disclosure.

As shown inFIG.2a, the stator outer periphery is formed in a surrounding manner by a plurality of ring-sector-shaped stator units111that are chain-connected. Each stator unit111is connected to the stator tooth, and each of the insulating wire frames1111is arranged on the stator unit111.

In this embodiment, the stator unit is made from a high-frequency silicon steel material, and the stator outer periphery is formed in a surrounding manner by a plurality of ring-sector-shaped stator units that are chain-connected, such that during machining of the stator outer periphery, two chained stator outer peripheries can cross each other, i.e., stator teeth of a second stator outer periphery are arranged between two stator teeth of a first stator outer periphery. Therefore, two stator outer peripheries can be produced by one time of die stamping, and the two stator outer peripheries are staggered, which, compared with production of one stator outer periphery by one time of stamping, greatly reduces silicon steel sheet consumption. In addition, in this embodiment, lines may be directly wound around each stator tooth since the stator outer peripheries are chain-connected, such that lines are wound around all the stator teeth at the same time, which improves the production efficiency, omits an installation process of embedding the coils in the stator grooves, and improves the production efficiency of the stator. Moreover, the stator outer periphery provided by the embodiment of the present disclosure may also enable the coils to firmly wrap around the stator teeth in order, which improves the rigidity of the stator teeth, and plays a role of protecting the stator teeth. Besides, the close coils may also be reduced.

In addition, it is worth mentioning that in the prior art, the winding group coil is embedded into the stator groove, and then a winding is secured at the stator groove, such that only more windings can be provided in order to increase the copper space factor of the stator groove. Compared with filling the stator grooves with the coils, the present disclosure has the advantage that since the lines are directly wound around the stator teeth to acquire the close windings, fewer copper wires are required while the same copper groove fill factor is achieved.

FIG.2bis a partial schematic diagram of a chain-connected stator unit according to an embodiment of the present disclosure.FIG.2cis a schematic diagram of a stator formed in a surrounding manner by a plurality of stator units according to an embodiment of the present disclosure.

As shown inFIGS.2band2c, in this embodiment, the stator outer periphery11is formed by: after the winding group coil13is formed upon winding the stator teeth12and one end of the winding group coil is led out by the insulating wire frame1111, extends around the outside of the stator outer periphery11in the circumferential direction and is connected to the winding group coil of the same phase, connecting the stator unit in the first place to the stator unit in the last place and welding connection wires of all the adjacent stator units.

In some embodiments, the connection wires of the adjacent stator units are welded.

In this embodiment, when the stator outer periphery is of a chain structure, winding of the stator teeth and connection of lines of the same phase are completed first, and then the chain-connected stator units are welded. Since outgoing lines of one ends of the first stator unit and the fourth stator unit that are chained are linearly connected in the length direction of the chain of the stator units, after the stator outer periphery is formed, the first stator unit and the fourth stator unit may be arranged along the arc of the stator outer periphery outside the stator outer periphery in the circumferential direction, such that the connection wires of the same phase can be tightened to be prevented from being loose, and hence noise of the stator is reduced.

In other words, inFIGS.2band2c, point A is one end of the insulating wire frame1111of the previous stator unit, point B is one end of the insulating wire frame of the next stator unit near point A, and point C is a welding point.

The connection wires may directly run from point A to point B before the stator outer periphery is formed in a surrounding manner, and the connection wires from point A to point B may be clung to the arc at the periphery of the stator after the stator outer periphery is formed in a surrounding manner by the stator units. In this way, the connection wires may be tightened to be prevented from being loose.

In some embodiments, one end of the stator tooth distal from the stator outer periphery is recessed to form a circular arc structure121. The circular arc structures of every two adjacent stator teeth are not connected, such that every two adjacent stator teeth and the stator outer periphery form a stator groove14, and the circular arc structures121of every two adjacent stator teeth are kept a predetermined distance away from each other in the circumferential direction, and the space of the two circular arc structures in the circumferential direction is a groove opening141of the stator groove.

In an embodiment, a circle formed in a surrounding manner by the circular arc structures121of the stator teeth is configured to accommodate the rotor2having two poles.

There are six stator teeth and six stator grooves.

The stator is of three phases, i.e., each phase is provided with two winding group coils. The number of parallel branches of the two winding group coils is 1 or 2, i.e., the two winding group coils may be connected in series or in parallel.

In some embodiments, when there are six stator teeth and the stator is of three phases, the two coils of the same phase may form an angle of 180°.

In an embodiment, the stator further includes a jumper16. After being led out through the first lead groove of the insulating wire frame1111, both ends of the two winding group coils of the same phase may be connected to the two outgoing ends of the winding group coils respectively through the jumpers16, such that the two coils form one phase line.

In some embodiments, the insulating wire frame1111may be integrally formed on the stator unit111, or detachably arranged on the stator unit111(in the stator unit shown inFIG.2, the insulating wire frame1111is not shown). For example, the insulating wire frame may be glued to the stator unit111, or fastened to the stator unit by a fastener such as a screw or a nail.

In an embodiment, the insulating wire frame1111may include a base and three protrusions arranged on the base, wherein the three protrusions are of the same height and spaced apart in a line to form a first lead groove and a second lead groove. The first lead groove is configured to lead out one end of the winding group coil to enable it to be connected to the winding group coil of the same phase around the outside of the stator outer periphery11in the circumferential direction.

In another embodiment, the insulating wire frame1111may be a cuboid component, which is etched in the length direction to form two lead grooves.

In some embodiments, the depths of the two lead grooves may be the same or different, and the widths of the two lead grooves may also be the same or different.

In an embodiment, the outgoing ends of the three phases are connected to the circuit board of the fan by the leads13A.

In an embodiment, the stator outer periphery11sequentially includes a first winding group coil, a second winding group coil, a third winding group coil, a fourth winding group coil, a fifth winding group coil and a sixth winding group coil in the circumferential direction, wherein a first end of the first winding group coil is connected to one end of the fourth winding group coil to form a first phase of the stator; a first end of the second winding group coil is connected to one end of the fifth winding group coil to form a second phase of the stator; and a first end of the third winding group coil is connected to one end of the sixth winding group coil to form a third phase of the stator, such that an angle between two of the winding group coils of the same phase is 180°.

In an embodiment, the stator further includes a wire clamping portion. The wire clamping portion is arranged on the side, distal from the stator teeth12, of a sixth insulating wire frame corresponding to the sixth winding group coil, and the sixth insulating wire frame includes a second lead groove, and the second lead groove is configured to lead an outgoing end of each phase to the wire clamping portion. Furthermore, the wire clamping portion may be of a U-shaped groove structure.

In some embodiments, the depth of the first lead groove corresponding to the first phase is greater than the depth of the lead groove corresponding to the second phase, and the depth of the first lead groove corresponding to the second phase is greater than the depth of the first lead groove corresponding to the third phase.

In some embodiments, the above six winding group coils are connected by means of “Y” connection or delta connection.

In the example shown inFIGS.1ato1c, the six winding group coils are connected by means of Y-connection, and every two coils are connected in series by the lead16to form one phase line, one end of which is one end of one coil and the other end of which is the other end of the other coil. Then, one end of each of the three phase lines is connected by the wire clamping portion15to become a wiring end, and the other end of each phase line is used as the outgoing end of the phase line. In the example shown inFIGS.1ato1c, the other ends of the first winding group coil, the third winding group coil and the fifth winding group coil are used as the outgoing ends of the three phases to further obtain the three phases of the stator. The outgoing end of each phase line may be connected to the circuit board of the fan by the lead13A.

In some embodiments, the insulating wire frames corresponding to the first winding group coil, the third winding group coil and the fifth winding group coil are all provided with third lead grooves, and the third lead grooves are configured to lead out the outgoing ends of all the phases. The outgoing end of each phase is connected to the circuit board of the fan by the lead13A.

In some embodiments, the wiring ends are arranged outside the side of one insulating wire frame1111distal from the winding group coil.

In an embodiment, the six winding group coils are connected by means of delta connection.

In some embodiments, after the two ends of the six winding group coils are led out by the insulating wire frames1111, the coils of the same phase are connected to obtain three phase lines, and six ends of the three phase lines are connected in sequence to obtain three outgoing ends of the three phases. That is, the tail end of a first phase line is connected to the head end of a second phase line, and the connection end point serves as one outgoing end of the three phases; the tail end of a second phase line is connected to the head end of a third phase line, and the connection end point serves as another outgoing end of the three phases; and the tail end of the third phase line is connected to the head end of the first phase line, and the connection end point serves as the last outgoing end of the three phases.

In some embodiments, the six ends of the three phase lines may be connected by the jumpers16.

FIG.3is a circuit diagram of a three-phase stator according to an embodiment of the present disclosure.

As shown inFIG.3, in this embodiment, the number of parallel branches of winding group coils of the same phase is 1, i.e., the tail end of one winding group coil of the same phase is connected to the head end of another winding group coil of the same phase so as to form one branch. That is, the winding group coils of the same phase are connected in series.

In the embodiment shown inFIG.3, the six stator coils include: a first coil131, a second coil132, a third coil133, a fourth coil134, a fifth coil135, and a sixth coil136which are arranged in the circumferential direction of the stator outer periphery clockwise or counterclockwise.

Here, the first coil and the fourth coil are set to be of a phase U, the second coil and the fifth coil to be of a phase V, and the third coil and the sixth coil to be of a phase W; two coils of the same phase form an angle of 180°; and two coils of the same phase are connected in series at an interval to form one branch.

FIG.4is a circuit diagram of a three-phase stator according to an embodiment of the present disclosure.

As shown inFIG.4, the number of parallel branches in the winding group coils of the same phase is 2. That is, the head end of one winding group coil of the same phase is connected to the head end of another winding group coil of the same phase, and the tail end of one winding group coil of the same phase is connected to the tail end of another winding group coil of the same phase to form two branches, i.e., the winding group coils of the same phase are connected in parallel.

In the embodiment shown inFIG.4, the six stator coils include a first coil, a second coil, a third coil, a fourth coil, a fifth coil and a sixth coil which are arranged in the circumferential direction of the stator outer periphery11clockwise or counterclockwise. Here, the first coil and the fourth coil are set to be of a phase U, the second coil and the fifth coil to be of a phase V, and the third coil and the sixth coil to be of a phase W; and two coils of the same phase are connected in parallel at an interval to obtain two branches.

In an embodiment, a yoke of the stator is provided with a semi-circular hole112for positioning the axial diffuser of the fan, and the center of the semi-circular hole112is provided on the center line of the stator tooth.

FIG.5is a schematic exploded diagram of a fan according to an embodiment of the present disclosure.

As shown inFIG.5, the fan includes the stator1provided by the foregoing embodiment and a rotor2, and the rotor2is a permanent magnet having two poles.

In one embodiment, the fan further includes a circuit board7, and an outgoing end of each phase of the stator is connected to the circuit board by a lead13A.

In another embodiment, after the coils of the stator are connected by means of “Y” connection or delta connection, one outgoing end of each phase is connected to the circuit board7and connected to a power supply by the circuit board7. For example, one outgoing end of each phase may be connected to the circuit board7by the lead13A.

Referring toFIGS.5to10, the fan further includes an axial diffuser3, an air hood4and an impeller5.

Here, the axial diffuser3is fixedly connected to the stator1, and includes an outer cylinder31, a main body32arranged in the outer cylinder31, and diffuser vanes33connected to the outer cylinder31and the main body32. The diffuser vanes33divide an annular space between the outer cylinder31and the main body32into a plurality of diffusion air passages34, and the main body32is provided with a central shaft hole35.

The air hood4is fixedly connected to the axial diffuser3, and an impeller chamber9and an annular gridless channel8surrounding the impeller chamber9are formed between the air hood4and the axial diffuser3. The impeller chamber9and the diffusion air passages are communicated by the annular gridless channel8. The air hood4is provided with an air inlet.

The impeller5is arranged in the impeller chamber9, and configured to introduce air from the air inlet41; and driven by the impeller5, air enters the diffusion air passages through the annular gridless channel8, and flows out from the other ends of the diffusion air passages.

In the fan provided by the embodiment of the present disclosure, radial diffusion is removed, and the axial diffuser3is used. The chaotic airflow from the impeller5directly enters the axial diffuser3after passing through the annular gridless channel8, and after being guided by the diffuser vanes33of the axial diffuser3, the flow tends to be stable, thereby reducing generation of vortexes in the flow channel. Removal of radial diffusion can effectively reduce the wind resistance and energy loss, such that the working efficiency of the fan is improved. Increasing the “dynamic-static gap” can weaken a “dynamic-static interference” effect caused during operation of the fan, such that the noise of the fan is reduced.

A radial diffuser generally lies in that axial diffusion vanes are provided at the annular gridless channel8according to the present disclosure to form a radial air passage that is in most cases very close to the vanes. After flowing out of the impeller5, air directly hits the front edges of the radial diffuser vanes33, resulting in strong “dynamic-static interference”. It is proved by a large number of documents that the “dynamic-static interference” generated by the rotor2and the vanes of the stator1is a main factor causing noise of the fan. In the fan provided by the embodiment of the present disclosure, a radial diffuser is replaced with the axial diffuser3to increase the “dynamic-static gap”, which is a very powerful means to reduce noise of the fan.

Due to removal of the radial diffuser, the diameter of the fan can be reduced accordingly, which solves the problems such as the shortened service life of a bearing6and the increased noise of the fan caused by the fact that the power has to be increased due to the increase of the diameter of the fan.

In some embodiments, the external diameter of the main body32of the axial diffuser3equals the external diameter of the stator1, such that air flowing out of the diffusion air passages34flows through the outside of the stator1. In an embodiment of the present disclosure, the external diameter of the main body32of the axial diffuser3equals the external diameter of the stator1, such that a fluid can flow out from the axial diffuser3through the outer periphery of the stator1without obstacles. Since air flows through the outside of the stator1, the wind resistance is reduced and the fluid efficiency is improved.

In an embodiment of the present disclosure, the external diameter of the main body32of the axial diffuser3and the external diameter of the stator1are equal, but not absolutely equal, allowing a certain difference. For example, the difference therebetween is 1%, 3%, 5%, 7%, 10%, etc.

In some embodiments, one of the axial diffuser3and the stator1includes a plurality of positioning posts36, and the other of the axial diffuser3and the stator1includes a plurality of semi-circular holes112adapted to the positioning posts36. The axial diffuser3and the stator1can be conveniently connected and fixed by correspondingly providing the positioning posts36and the semi-circular holes112on the axial diffuser3and the stator1respectively.

The positioning posts36may be provided on any one of the axial diffuser3and the stator1, and the semi-circular holes112are formed in the other thereof. For example, the positioning posts36may be provided on the axial diffuser3, and the semi-circular holes112may be formed in the stator1.

In some embodiments, the positioning posts36extend in the axial direction of the axial diffuser3. In an exemplary embodiment, part of the diffuser vanes33of the axial diffuser3extend in the axial direction of the axial diffuser3to form the positioning posts36, and the stator1includes the semi-circular holes112. The number of the positioning posts36is not the same as the number of the diffuser vanes33. Generally, the number of the positioning posts36may be smaller than the number of the diffuser vanes33. Therefore, when the positioning posts36are arranged on the axial diffuser3, part of the diffuser vanes33may extend in the axial direction to form the positioning posts36. For example, three of the twelve diffuser vanes33extend in the axial direction to form the positioning posts36. In an embodiment of the present disclosure, the diffuser vanes33extend in the axial direction of the axial diffuser3to form the positioning posts36, such that the positioning posts36can have sufficient strength without adversely affecting the structure of the axial diffuser3, and meanwhile, the consumption of materials can be reduced. Thus, in order to improve the strength of the positioning posts, there is no need to increase the thicknesses of the parts where the positioning posts36are located.

In an exemplary embodiment, the end portions of the diffuser vanes33may integrally extend in the axial direction of the axial diffuser3to form the positioning posts36. Alternatively, part of the end portions of the diffuser vanes33may extend in the axial direction of the axial diffuser3to form the positioning posts36. When part of the end portions of the diffuser vanes33extend in the axial direction of the axial diffuser3to form the positioning posts36, for example, the sides of the diffuser vanes33close to the main body32may extend in the axial direction of the axial diffuser3to form the positioning posts36.

In some embodiments, the positioning posts36may be formed on the main body32. In an exemplary embodiment, the positioning posts36may be located at the positions of the main body32corresponding to the diffuser vanes33.

In some embodiments, one positioning post may be partially formed on the main body32and partially formed by extension of the diffuser vanes33.

In an embodiment of the present disclosure, the semi-circular holes112may be hole grooves or open grooves. In some embodiments, the outer peripheral surface of the stator1is recessed to form the semi-circular hole112. The semi-circular hole112formed by recessing the outer peripheral surface of the semi-circular hole is the open groove, which can not only ensure stable positioning, but also saves materials while guaranteeing the strength. The wall surface of the semi-circular hole112is a cylindrical surface, and the positioning post36is provided with a cylindrical surface adapted to the wall surface of the semi-circular hole112. The wall surface of the semi-circular hole112and the correspondingly adapted surface of the positioning post36are cylindrical, which effectively ensures the stability in their combination.

In some embodiments, the positioning post36is semi-cylindrical. One side of the positioning post36is provided with a cylindrical surface adapted to the wall surface of the semi-circular hole112, and the other side thereof is matched with the peripheral surface of the stator1.

In an embodiment of the present disclosure, the semi-circular hole112may be provided at any position on the peripheral surface of the stator1. In some embodiments, the semi-circular hole112is located on the outer peripheral surface corresponding to the tooth centerline of the stator1. The semi-circular holes112are provided on the outer peripheral surface opposite to teeth of the stator1. There is enough space for the semi-circular hole112in this part, and the strength is ensured without additionally increasing the dimensions such as the thickness of the part where the semi-circular hole112is located, such that the consumption of materials is reduced.

In an embodiment of the present disclosure, the number of the semi-circular holes112or the number of the positioning posts36is not specifically limited, for example, they may be two, three, four, etc. In some embodiments, there are three semi-circular holes112and three positioning posts36, which are uniformly distributed on their respective circumferences. There are three semi-circular holes112and three positioning posts36, which can ensure the positioning connection between the axial diffuser3and the stator1. A plurality of semi-circular holes51is distributed on one circumference, a plurality of positioning posts36is also uniformly distributed on one circumference, and the two circumferences have the same diameter. Since the semi-circular holes112and the positioning posts36are uniformly distributed on their respective circumferences, when the axial diffuser3and the stator1are connected, it is unnecessary to limit them in specific orientations. Any one of the positioning posts36may be adapted to any one of the semi-circular holes112.

In an embodiment of the present disclosure, the fixed connection mode between the axial diffuser3and the stator1is not limited. For example, the axial diffuser3and the stator1may be glued, or connected by interference fit, or connected by a screw, etc.

In some embodiments, the axial diffuser3is provided with one or more connecting posts113, and the stator1is provided with one or more connecting holes37adapted to the connecting posts113. Alternatively, the axial diffuser3is provided with one or more connecting holes, and the stator1is provided with one or more connecting posts adapted to the connecting holes. According to the present disclosure, by taking that the stator is provided with the connecting posts113as an example, the axial diffuser3and the stator1are connected together by matching the connecting holes37to the connection posts113. For example, the connecting posts113and the hole walls of the connecting holes37are fixedly connected by glue. In this way, glue may be applied in a specific position to avoid defects such as glue overflow. Alternatively, the connecting posts113and the connecting holes37are fixedly connected by interference fit.

In an exemplary embodiment, the axial diffuser3includes a plurality of connecting holes37, and the stator1includes a plurality of connecting posts113adapted to the connecting holes37. For example, a plurality of connecting holes37may be formed in the main body32.

In the fan provided by the embodiment of the present disclosure, the connecting posts113and the connecting holes37corresponding to each other as well as the positioning posts36and the semi-circular holes112corresponding to each other may be included at the same time.

In some embodiments, the axis of the circle where the connecting posts113and the connecting holes37corresponding to each other are located is collinear with the axis of the circle where the positioning posts36and the semi-circular holes112corresponding to each other are located. In an exemplary embodiment, the radius of the circle where the connecting posts113and the connecting holes37corresponding to each other are located may be smaller than the radius of the circle where the positioning posts36and the semi-circular holes112corresponding to each other are located.

In some embodiments, the lengths of the connecting posts113are smaller than the lengths of the positioning posts36. During assembly, the positioning of the axial diffuser3and the stator1may be achieved by adapting the positioning posts36for the semi-circular holes112, such that the connecting posts53correspond to the connecting holes37to facilitate assembly.

In some embodiments, the end face of the outer cylinder31close to the air hood4is provided with a first annular protrusion, such that the end face of the outer cylinder31forms a first stepped surface; and one side of the outer wall surface of the outer cylinder31extends axially to form the annular protrusion. The air hood4is provided with a second annular protrusion22, such that the end face of the air hood4connected to the outer cylinder31forms a second stepped surface; and the second stepped surface is adapted to the first stepped surface. The stepped surface is provided at the part where the outer cylinder31is connected to the air hood4, such that the inner wall surface of the part where the air hood4is connected to the outer cylinder31is in smoother transition, which reduces interference to the fluid.

In some embodiments, the impeller5is provided with an odd number of vanes. For example, the number of vanes of the impeller5is three, five, seven, nine, eleven, etc. Since the impeller5is provided with an odd number of vanes, asymmetrical injection residual stress and resonance can be reduced.

In some embodiments, the number of vanes of the impeller5and the number of the diffuser vanes33are not multiples of each other. The number of the diffuser vanes33is selected not to be exactly divided by the number of vanes of the impeller5, such that air noise can be reduced. For example, the number of vanes of the impeller5is seven, and the number of the diffuser vanes33is twelve.

In some embodiments, the number of the diffuser vanes33is a multiple of three. The number of the diffuser vanes33is a multiple of three to facilitate arrangement of the positioning posts36. Three positioning posts36may ensure positioning of the axial diffuser3and the stator1. The positioning posts36are uniformly distributed on the circumference, facilitating assembly of the axial diffuser3and the stator1. When the positioning posts36are formed by extension of the diffuser vanes33, the number of the diffuser vanes33being a multiple of three may ensure uniform distribution of the positioning posts36. For example, the number of the diffuser vanes33may be nine, twelve, fifteen, or the like. Certainly, in the embodiment of the present disclosure, it is not excluded that the number of the diffuser vanes33is a number other than a multiple of three.

In some embodiments, the number of vanes of the impeller5is smaller than the number of the diffuser vanes33. The number of the diffuser vanes33meets the rectification efficiency while the vanes of the impeller5meet the suction efficiency,

In some embodiments, the diffuser vanes33may be inclined, i.e., the axes of the diffuser vanes33are not parallel to the axis of the axial diffuser3. The axis of the diffusion air passage34is not parallel to the axis of the axial diffuser3, either. In an exemplary embodiment, the axis of the diffusion air passage34and the axis of the axial diffuser3may form an angle of 10° to 45°.

In an embodiment of the present disclosure, the axial diffuser3is assembled on a motor shaft10by a bearing4, and the impeller5is fixed on a motor.

The fan provided by the embodiment of the present disclosure further includes a rotor2and a circuit board7. The rotor2is fixed on the motor shaft10. The circuit board7is connected to the stator1.

A cleaning device is provided according to an embodiment of the present disclosure. The cleaning device includes the fan as described in any one of the foregoing embodiments.

In the fan of the cleaning device provided by the embodiment of the present disclosure, radial diffusion is removed, and the axial diffuser3is used. The chaotic airflow from the impeller5directly enters the axial diffuser3after passing through the annular gridless channel8, and after being guided by the diffuser vanes33of the axial diffuser3, the flow tends to be stable, thereby reducing generation of vortexes in the flow channel. Removal of radial diffusion can effectively reduce the wind resistance and energy loss, such that the working efficiency of the fan is improved. Increasing the “dynamic-static gap” can weaken a “dynamic-static interference” effect cause during operation of the cleaning device, such that the noise of the fan is reduced.

The radial diffuser is generally provided at the annular gridless channel8, which is in most cases very close to the vanes. After flowing out of the impeller5, air directly hits the front edges of the radial diffuser vanes33, resulting in strong “dynamic-static interference”. It is proved by a large number of documents that the “dynamic-static interference” generated by the rotor2and the vanes of the stator1is a main factor causing noise of the fan. In the fan of the cleaning device provided by the embodiment of the present disclosure, a radial diffuser is replaced with the axial diffuser3to increase the “dynamic-static gap”, which is a very powerful means to reduce noise of the fan.

Due to removal of the radial diffuser, the diameter of the fan can be reduced accordingly, which solves the problems such as the shortened service life of a bearing6and the increased noise of the fan caused by the fact that the power has to be increased due to the increase of the diameter of the fan.

According to another aspect of the present disclosure, a cleaning device is provided. The cleaning device is provided with the fan as defined in any one of the above technical solutions. The cleaning device provided by the present embodiment includes a floor mopping robot, a hand-held vacuum cleaner, etc.

It should be understood that the specific embodiments of the present disclosure are only used to illustrate or explain the principles of the present disclosure, and should not constitute any limitation to the present disclosure. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present disclosure should be included within the protection scope of the present disclosure. Furthermore, the appended claims of the present disclosure are intended to cover all changes and modifications that fall within the scopes and boundaries of the appended claims, or equivalents of such scopes and boundaries.