Patent Publication Number: US-2023148808-A1

Title: Fan assembly and vacuum cleaner with fan assembly

Description:
TECHNICAL FIELD 
     The disclosure relates to the technical field of vacuum cleaners, in particular to a fan assembly and a vacuum cleaner with the fan assembly. 
     BACKGROUND 
     Vacuum cleaner is a kind of electrical appliances commonly used in production and life, mainly used for cleaning and collecting dust and debris. The conventional vacuum cleaners on the market have good performance when cleaning up dust, garbage and other debris with low adsorption on the carpet and the ground. However, it is impossible to completely clean up the dust attached to the wall or the cracks or the debris with certain adhesion, which seriously affects users’ experience of the conventional vacuum cleaner. 
     Therefore, it is necessary to further improve the conventional vacuum cleaner to solve the problems mentioned above. 
     SUMMARY 
     In view of this, a fan assembly and a vacuum cleaner with the fan assembly are provided to solve the problem that the conventional vacuum cleaner cannot completely clean up the dust attached to the wall or the cracks or the debris with certain adhesion. 
     The disclosure provides a fan assembly and the fan assembly includes a motor, an impeller and a fan housing. The impeller is driven by the motor, which includes an impeller air outlet and an impeller air inlet. The impeller air inlet is located in an axial direction of the impeller, and the impeller air outlet is located in a radial direction of the impeller. An air channel is defined inside the fan housing, and the impeller is at least partially housed in the fan housing. The impeller rotates relative to the fan housing about a rotational axis, a generated airflow enters the air channel during the rotation of the impeller, and a height of the fan housing in the direction of the rotational axis increases along the direction of the air flow. 
     In an embodiment of the disclosure, the fan housing includes an upper housing and a lower housing, the upper housing has an inverted U-shaped cross section along the direction of the rotational axis, and the lower housing is arranged below the upper housing and being a spiral air channel with the upper housing. 
     In an embodiment of the disclosure, the upper housing includes a first end, a spiral part spirally extending upward from the first end, and a second end located at an end of the spiral part, and base surfaces of the first end, the spiral part, and the second end are in a same plane. 
     In an embodiment of the disclosure, the lower housing includes a bottom wall and a side wall arranged along a circumferential direction of the bottom wall, and the side wall of the lower housing is connected with the side wall of the upper housing. 
     In an embodiment of the disclosure, a top surface of the spiral part is spiraling in the direction of the airflow. 
     In an embodiment of the disclosure, a top surface of the spiral part gradually spirally extends upward along a helix angle and the helix angle is between 3° and 35°. 
     In an embodiment of the disclosure, a ratio of a rated rotating speed of the impeller to a diameter of the impeller is not less than 220, and the rated rotating speed of the impeller is not less than 20000 rpm. 
     In an embodiment of the disclosure, the diameter of the impeller is between 60 mm and 80 mm. 
     The disclosure provides a vacuum cleaner, and the vacuum cleaner includes a housing, a dust suction assembly, a filter assembly, and a fan assembly. A dust collection cavity, a mounting cavity, and a through hole communicating the dust collection cavity and the mounting cavity are arranged in the housing. One end of the dust suction assembly passing through the housing and extending to the dust collection cavity. The filter assembly is arranged in the dust collection cavity. The fan assembly is arranged in the mounting cavity, and the fan assembly includes a motor, an impeller and a fan housing. The impeller is driven by the motor, and the impeller includes an impeller air outlet and an impeller air inlet. The impeller air inlet is located in an axial direction of the impeller and communicated with the through hole, and the impeller air outlet is located in a radial direction of the impeller. An air channel is formed inside the fan housing, and the impeller is at least partially housed in the fan housing. The impeller rotates relative to the fan housing about a rotational axis, a generated airflow enters the air channel during a rotation of the impeller, and a height of the fan housing in a direction of the rotational axis increases along a direction of the air flow. 
     In an embodiment of the disclosure, the housing includes a dust collector, a middle cover assembly and an upper cover assembly, the middle cover assembly is arranged above the dust collector and forms the dust collection cavity with the dust collector, the upper cover assembly is arranged above the middle cover assembly and forms the mounting cavity with the middle cover assembly. 
     In an embodiment of the disclosure, the fan housing includes an upper housing and a lower housing, the upper housing has an inverted U-shaped cross section along the direction of the rotational axis, and the lower housing is arranged below the upper housing and being a spiral air channel with the upper housing. 
     In an embodiment of the disclosure, the middle cover assembly includes a middle cover body and a recessed part formed through denting downwardly from the middle cover body, the through hole is arranged on an bottom wall of the recessed part, the fan assembly is housed in the recessed part, the recessed part is the lower housing of the fan housing, and a circular arc structure is formed at a position of the recessed part corresponding to the upper housing of the fan housing to guide high-pressure airflow around the impeller upwards into the air channel. 
     In an embodiment of the disclosure, the upper housing of the fan assembly includes a first end, a spiral part spirally extending upward from the first end, and a second end located at an end of the spiral part, and base surfaces of the first end, the spiral part, and the second end are in a same plane. 
     In an embodiment of the disclosure, a height of the spiral part close to the first end is lower than a height of the spiral part close to the second end, a top surface of the spiral part is spiraling along in the direction of the airflow. 
     In an embodiment of the disclosure, a top surface of the spiral part gradually spirally extends upward along a helix angle and the helix angle is a constant value. 
     In an embodiment of the disclosure, the helix angle is between 3°and 35°. 
     In an embodiment of the disclosure, the helix angle is 35°. 
     In an embodiment of the disclosure, the upper cover assembly includes a battery cavity housing a battery pack, a battery pack cover is arranged on an upper part of the battery cavity, and the battery pack cover is movably connected with the upper cover assembly. 
     In an embodiment of the disclosure, the dust suction assembly is arranged on the upper cover assembly, the dust suction assembly includes a throat pipe and a dust suction accessory connected to the throat pipe, the throat pipe includes a soft throat pipe and a hard throat pipe arranged on both sides of the soft throat pipe, a first side of the soft throat pipe is fixed on the upper cover assembly through the hard throat pipe, and a second side of the soft throat pipe is connected to the dust suction accessory through the hard throat pipe. 
     In an embodiment of the disclosure, the upper cover assembly further includes an accessory groove housing the dust suction accessory. 
     In an embodiment of the disclosure, the upper cover assembly is provided with a fixing component to fix the hard throat pipe and a groove to house the soft throat pipe, the fixing component is a circular arc-shaped gasket, as in a storing state, the hard throat pipe at the second side is located on the gasket to match the groove to fix and limit the throat pipe. 
     In an embodiment of the disclosure, the upper cover assembly is provided with an air inlet communicated with the dust suction assembly, and an air outlet is arranged between the middle cover assembly and the upper cover assembly. 
     In an embodiment of the disclosure, the motor is a brushless motor. 
     In an embodiment of the disclosure, the brushless motor includes a fan blade for heat dissipation, and the fan blade is arranged between the brushless motor and the impeller. 
     In an embodiment of the disclosure, a ratio of a rated rotating speed of the impeller to a diameter of the impeller is not less than 220, and the rated rotating speed of the impeller is not less than 20000 rpm. 
     In an embodiment of the disclosure, the diameter of the impeller is between 60 mm and 80 mm. 
     In summary, the fan assembly of the disclosure is provided with a spiral air channel in the fan housing, so that when the motor rotates, the fan blade can be driven to rotate and a high-pressure airflow is formed at the top of the fan blade. Then the high-pressure airflow flows out along the spiral air channel in the fan housing. The spiral air channel is beneficial to reduce wind pressure loss and wind resistance, increase air flow, and improve the suction effect and working efficiency of the vacuum cleaner to a certain extent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to explain the embodiments of the disclosure or the technical solutions in the conventional art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the conventional art. Obviously, the drawings in the following description are only some embodiments of the disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. 
         FIG.  1    is a perspective view of a vacuum cleaner of the disclosure. 
         FIG.  2    is an exploded view of the vacuum cleaner shown in  FIG.  1   . 
         FIG.  3    is a perspective view of a dust collector in  FIG.  2   . 
         FIG.  4    is a perspective view of a middle cover assembly in  FIG.  2   . 
         FIG.  5    is a perspective view of an upper cover assembly in  FIG.  2   . 
         FIG.  6    is another perspective view of the upper cover assembly shown in  FIG.  5   . 
         FIG.  7    is a perspective view of a dust suction assembly in  FIG.  2   . 
         FIG.  8    is a state view when a battery pack cover of the vacuum cleaner shown in  FIG.  1    is opened. 
         FIG.  9    is a cross-sectional view of the vacuum cleaner shown in  FIG.  1   . 
         FIG.  10    is a partial enlarged view of a circle shown in  FIG.  9   . 
         FIG.  11    is a perspective view of a fan housing in  FIG.  2   . 
         FIG.  12    is a perspective view of the fan housing in  FIG.  2    from another angle. 
         FIG.  13    is a cross-sectional view of a fan assembly in  FIG.  2   . 
     
    
    
     DETAILED DESCRIPTION 
     The following describes the implementation of the disclosure through specific embodiments, and those skilled in the art can easily understand other advantages and effects of the disclosure from the content disclosed in this specification. The disclosure can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the disclosure. It should be noted that, the following embodiments and the features in the embodiments can be combined with each other without conflict. It should further be understood that the terms used in the examples of the disclosure are used to describe specific embodiments, instead of limiting the protection scope of the disclosure. The test methods that do not indicate specific conditions in the following examples are usually in accordance with conventional conditions, or conditions recommended by each manufacturer. 
     It should be noted that the structure, scale, size, etc. of the drawings in this specification are merely for illustration of the disclosed content for understanding and reading by those skilled in the art, and do not intend to limit the restrictive conditions under which the disclosure can be implemented, so it has no technical significance. Any structural modification, proportional relationship change or size adjustment should still be within the scope of the technical content disclosed in the disclosure, without affecting the effects and objectives that can be achieved by the disclosure. At the same time, the terms such as “upper”, “lower”, “left”, “right”, “middle” and “one” cited in this specification are only for the convenience of description and are not used to limit the scope of the disclosure. The change or adjustment of the relative relationship should also be regarded as the applicable scope of the disclosure without substantial change in the technical content. 
     The disclosure provides a fan assembly and a vacuum cleaner with the fan assembly. The vacuum cleaner can improve the suction effect to a certain extent, which improves work efficiency. 
     Please refer to  FIG.  1    to  FIG.  4    and  FIG.  9   . The disclosure provides a vacuum cleaner  100 , the vacuum cleaner  100  includes a housing, a dust suction assembly  5 , a filter assembly  4  and a fan assembly  6 . The housing is provided with a dust collection cavity  13 , a mounting cavity  24 , and a through hole  221  communicating the dust collection cavity  13  and the mounting cavity  24 . The dust suction assembly  5  is arranged on the housing and communicates with the dust collection cavity  13 . The filter assembly  4  is arranged in the dust collection cavity  13 . The fan assembly  6  is installed in the mounting cavity  24 . 
     Please refer to  FIG.  1    through  FIG.  6   , the housing includes a dust collector  1 , a middle cover assembly  2  arranged above the dust collector  1  and an upper cover assembly  3  covering the middle cover assembly  2 . A dust collection cavity  13  is formed between the dust collector  1  and the middle cover assembly  2 , and a mounting cavity  24  is formed between the upper cover assembly  3  and the middle cover assembly  2 . The upper cover assembly  3  is provided with an air inlet  30  communicating with the dust suction assembly  5 , and an air outlet 30′ is arranged between the middle cover assembly  2  and the upper cover assembly  3 . The dust collector  1  is capable of being made into various shapes. In one embodiment, the dust collector  1  is rectangular and includes a bottom wall  11  and a side wall  12  for connecting the bottom wall  11  and the middle cover assembly  2 . The side walls  12  are provided with four and jointly define a housing space with the bottom wall  11 . The middle cover assembly  2  protrudes into the housing space and forms a dust collection cavity  13  with it, and the filter assembly  4  is housed in the dust collection cavity  13 . The fan assembly  6  is arranged in the mounting cavity  24  between the middle cover assembly  2  and the upper cover assembly  3  and communicates with connecting the dust collector  1 . The side wall  12  of the dust collector  1  is also provided with a connecting part  14  for connecting and fixing the middle cover assembly  2  and the upper cover assembly  3 . In this embodiment, the connecting part  14  is configured as a movable buckle, so that the middle cover assembly  2  and the upper cover assembly  3  are detachably fixed on the dust collector  1 . 
     Please refer to  FIG.  2    and  FIG.  4   , the middle cover assembly  2  includes a middle cover body  21  arranged on the dust collector  1  and a recessed part  22  denting from the middle cover body  21  toward the inside of the dust collector  1 . In addition, the bottom wall of the recessed part  22  is provided with a through hole  221  for communicating the dust collection cavity  13  and the mounting cavity  24 . In this embodiment, the middle cover assembly  2  is embedded and fixed on the dust collector  1 , and a sealing ring  20  is also arranged between the middle cover assembly  2  and the dust collector  1  to ensure that the middle cover assembly  2  and the dust collector  1  are arranged tightly and prevent air from escaping into the dust collector  1  from the gap between mounting positions of the middle cover assembly  2  and the dust collector  1  due to the pressure difference during the working process of the vacuum cleaner  100 , which ensures the working efficiency of the vacuum cleaner  100 . Specifically, during the assembly process of the vacuum cleaner  100  of the disclosure, at first, the middle cover assembly  2  is fixed on the dust collector  1 . Secondly, the upper cover assembly  3  is used to cover on the middle cover assembly  2 . At last, the connecting part  14  is fastened to fix the middle cover assembly  2  and the upper cover assembly  3  on the dust collector  1 , which ensures that the upper cover assembly  3  and the middle cover assembly  2  are stably connected with the dust collector  1  during the working process. 
     Please refer to  FIG.  2   ,  FIG.  5   ,  FIG.  6    and  FIG.  8   , the upper cover assembly  3  is used to cover on the middle cover assembly  2  and is detachably connected with the dust collector  1  through the connecting part  14 . A battery cavity  31  for housing a battery pack  200  is formed in the upper cover assembly  3 , a battery insert  32  is arranged in the battery cavity  31 , and the battery insert  32  is arranged corresponding to the battery pack  200 . The battery cavity  31  is formed through denting from a top of the upper cover assembly  3  toward the dust collector  1  (downward). Correspondingly, the position of the middle cover assembly  2  corresponding to the battery cavity  31  is recessed in the direction of the dust collector  1  to receive the battery cavity  31 , and the battery cavity  31  is arranged on a different side of the recessed part  22  of the middle cover assembly  2 . With this arrangement, a motor  61  and the battery pack  200  are respectively located at two ends of the vacuum cleaner  100 , so that the center of gravity of the vacuum cleaner  100  is approximately at the center of the housing, thereby avoiding the problem that the vacuum cleaner  100  is difficult to carry due to one side being too heavy. The battery pack  200  is housed in the battery cavity  31  and plugged on the battery insert  32  to provide power to the vacuum cleaner  100 . An upper part of the battery cavity  31  is provided with a battery pack cover  33  covering the battery cavity  31 , and the battery pack cover  33  is movably connected with the upper cover assembly  3 . In this embodiment, the battery pack cover  33  and the upper cover assembly  3  are pivotally connected, and it can be understood that the connection method is not limited to this. With this arrangement, the battery pack  200  of the vacuum cleaner  100  of the disclosure is capable of being mounted and removed only through opening the battery pack cover  33 , which improves the convenience to use the vacuum cleaner  100 . The upper cover assembly  3  is further provided with a handle  34 , and the handle  34  is capable of being freely rotated on the upper cover assembly  3  to facilitate the use and movement of the vacuum cleaner  100 . 
     Please refer to  FIG.  2    and  FIG.  7   , the dust suction assembly  5  includes a throat pipe  51  and a dust suction accessory  52  connected with the throat pipe  51 . The throat pipe  51  includes a soft throat pipe  511  and a hard throat pipe  512  arranged on both sides of the soft throat  511 . A first side of the soft throat pipe  511   is fixed on the upper cover assembly  3  through the hard throat pipe  512  and a connecting part  513 , and a second side is connected to the dust suction accessory  52  through the hard throat pipe  512 , so that the throat pipe  51  is capable of working through the dust suction accessory  52 . The dust suction accessory  52  is capable of being a commonly used accessory of the vacuum cleaner  100  such as a floor brush, a flat vacuum, a round brush, a bed sheet brush, a sofa vacuum and so on, which means that the dust suction accessory  52  is capable of being selected and replaced according to the location where the vacuum cleaner  100  is used, and it is not limited here. 
     Please refer to  FIG.  2   ,  FIG.  5    through  FIG.  8   , an accessory groove  35  for housing the dust suction accessory  52  is further formed in the upper cover assembly  3 , and the accessory groove  35  is recessed from the top of the upper cover assembly  3  toward the dust collector  1 . Preferably, the accessory groove  35  is located beside the battery cavity  31  and is simultaneously covered by the battery pack cover  33 . With this arrangement, not only the dust suction accessory  52  can be stored well, be convenient for storage and avoid damage, but also it is convenient for access. Under the condition that the connection between the upper cover assembly  3  with the middle cover assembly  2  and the dust collector  1  is maintained, the dust suction attachment  52  is capable of being replaced as needed. The upper cover assembly  3  is also provided with a fixing component  36  for fixing the hard throat  512  and a groove  37  for housing the soft throat  511 . The groove  37  is formed through denting downwardly from an upper surface of the upper cover assembly  3 . The fixing component  36  is an arc-shaped gasket. In the storage state, the hard throat pipe  512  at the second side is placed on the gasket  36  to match the groove  37  to jointly fix and limit the throat pipe  51 , which makes the throat  51  be fixed on the upper cover assembly  3 . 
     Please refer to  FIG.  2   ,  FIG.  4    and  FIG.  10    through  FIG.  13   , the fan assembly  6  includes a motor  61 , an impeller  62  and a fan housing. The impeller  62  is arranged on the output shaft of the motor  61  and is driven by the motor  61 . The impeller  62  includes an impeller air outlet  622  and an impeller air inlet  621 . The impeller air inlet  621  is located in the axial direction of the impeller  62  and is communicated with the through hole  221 . The impeller air outlet  622  is located in the radial direction of the impeller  62 . An air channel  631  is formed in the fan housing, the impeller  62  is at least partially housed in the fan housing, and a height of the fan housing in the direction of a rotational axis increases along the direction of the airflow. In an embodiment, the fan assembly  6  is arranged in the recessed part  22  of the middle cover assembly  2 . Specifically, the motor  61  is placed vertically. The impeller  62  is connected to the motor shaft  611  of the motor  61 , and the impeller  62  is housed in the recessed part  22 . The impeller air inlet  621  is located on the axis of the impeller  62  and is directly opposite to the through hole  221  on the bottom wall of the recessed part  22 . The outlet direction of the impeller air outlet  622  is perpendicular to the axis of the impeller  62 . Therefore, when the motor  61  rotates, the impeller  62  is driven to rotate and a high pressure area is formed at a top of the impeller  62 , so that the airflow moves from a low pressure area to a high pressure area, and a spiral upward airflow direction with the vertical direction as an axis is generated at the position of the fan assembly  6 . The fan housing includes an upper housing  63  and a lower housing. The upper housing  63  is a ring-shaped structure, and the bottom thereof is in a shape of an opening, so that the cross section in the direction of the rotational axis of upper housing  63  of the fan housing is in an inverted U-shape. An inner side wall  633  of the upper housing  63  is connected by a connecting plate  635 , and the connecting plate  635  is provided with a through hole for the motor shaft  611  to pass through. The lower housing includes a bottom wall and side walls arranged in the circumferential direction along the bottom wall. The side walls of the lower housing are connected with outer side walls  634  of the upper housing  63 , so that the upper housing  63  and the lower housing form an air channel  631 . In this embodiment, the bottom wall of the recessed part  22  of the middle cover assembly is the lower housing of the fan housing, and the air channel  631  is formed by the combination of the upper housing  63  of the fan housing and the bottom wall of the recessed part  22  of the middle cover assembly  2 . Preferably, a circular arc structure  23  is formed at the position of the recessed part  22  corresponding to the upper housing  63  of the fan housing, and the circular arc structure  23  is used to guide high-pressure airflow around the impeller  62  upwards into the air channel  631 . In other embodiments, the lower housing can also be set up separately, so that an air channel  631  is formed between the upper housing  63  and the lower housing, which is not limited to this. 
     Please refer to  FIG.  9    through  FIG.  11   , the upper housing  63  of the fan housing is provided with a first end A, a spiral part  632  spirally extending upward from the first end A, and a second end B located at the end of the spiral part  632 . In other words, the spiral part  632  spirals from the first end A to the second end B until the first end A and the second end B merge. At this time, a round of spiral is completed. A fan air outlet  636  is arranged at the second end B of the upper housing  63  of the fan housing. The fan air outlet  636  communicates with the air outlet 30′. The high-pressure airflow spirally flows in the air channel  631  and is finally discharged from the air outlet 30′. After the high-pressure airflow is discharged from the air outlet 30′, a negative pressure is formed inside the dust suction assembly  5 , which encourages external air to enter the soft throat pipe  511  from the dust suction accessory  52 , and the function of the vacuum cleaner  100  is completed at this time. In this embodiment, the base surfaces of the first end A, the spiral part  632 , and the second end B are in the same plane, and the height of the spiral part  632  close to the first end A is lower than the height of the spiral part  632   close to the second end B, so that the top surface of the spiral part  632  is spiral. The top surface of the spiral part  632  is designed as a spiral shape to form a spiral air channel  631  inside the fan housing. Of course, in other embodiments, the overall height of the spiral part  632  may be kept constant, and then a groove is formed at the bottom of the spiral part  632  to form a spiral air channel  631 , which is not limited here. In this embodiment, the top surface of the spiral part  632  gradually spirally extends upward along the helix angle α. The helix angle α is preferably a constant angle. As shown in  FIG.  11   , the helix angle α is the angle between a tangent of the helix on the top surface and a plane perpendicular to a helix axis (i.e., the horizontal plane). In this embodiment, the helix angle is one of the important parameters that affect the wind resistance of the air channel and the work efficiency. 
     Table 1 shows that the upper housings  63  of the fan housing with different helix angles are applied to the vacuum cleaner  100 . When the vacuum cleaner  100  is working normally (which means when the working voltage remains the same), current, shaft power, fluid power, flow, total pressure and work efficiency will be analyzed and then specific values can be obtained. The specific values are shown in the table below. 
     
       
         
          TABLE 1
           
               
               
               
               
               
               
               
               
             
               
                 helix angle 
                 voltage 
                 current 
                 Shaft power 
                 fluid power 
                 flow 
                 total pressure 
                 work efficiency 
               
             
            
               
                 o 
                 V 
                 A 
                 W 
                 W 
                 1/s 
                 KPa 
                 % 
               
               
                 3° 
                 36.0 
                 9.17 
                 330 
                 95 
                 10.5 
                 7.2 
                 28.8% 
               
               
                 8° 
                 36.0 
                 8.53 
                 307.1 
                 98.2 
                 11.7 
                 8.4 
                 32% 
               
               
                 12° 
                 36.0 
                 9.35 
                 336.6 
                 108.3 
                 11.2 
                 9.67 
                 32.2% 
               
               
                 20° 
                 36.0 
                 8.55 
                 307.8 
                 101 
                 11.7 
                 8.6 
                 32.8% 
               
               
                 35° 
                 36.0 
                 8.89 
                 320 
                 108 
                 12.1 
                 8.9 
                 34% 
               
            
           
         
       
     
     It can be seen from the above table: under the voltage of 36 V, the helix angle is set between 3° to 35°. When the helix angle is 3°, the working efficiency of the vacuum cleaner  100  reaches 28.8%, and when the helix angle is 8°, the working efficiency of the vacuum cleaner  100  reaches 32%. At this time, the current value, the shaft power and the total voltage are all low. When the helix angle is 12 °, the working efficiency of the vacuum cleaner  100  is 32.2%, and the current value, the shaft power, the fluid power and the total pressure are all high at this time. When the helix angle is 20°, the working efficiency of the vacuum cleaner  100  is 32.8%. When the helix angle is 35°, the working efficiency of the vacuum cleaner  100  reaches 34%, which is the highest value, and at the same time the flow also reaches the maximum. From this data, it can be concluded that under the same voltage, when the helix angle of the spiral part  632  is between 3 degrees to 35 degrees, the working efficiency of the vacuum cleaner  100  will gradually increase and reach the highest value when the helix angle is 35°. Therefore, the helix angle of the top surface of the spiral part  632  is preferably 3 degrees to 35 degrees. Such a design is beneficial to reduce wind pressure loss and wind resistance, improve air flow, and increase work efficiency by about 10% to a certain extent. 
     Please refer to  FIG.  13   , in one embodiment, the motor  61  can be selected as a brushless motor. The brushless motor is not provided with brushes, so that the brushless motor can rotate at a high speed with low noise. Secondly, the volume of the brushless motor is smaller, which can free up more space for housing the battery assembly and extend the endurance time of the vacuum cleaner  100 . The brushless motor is also provided with a fan blade  612  for heat dissipation. The fan blade  612  is located between the brushless motor and the impeller  62 . When the brushless motor is working, the fan blade  612  is driven by the brushless motor to rotate, thereby driving wind from an end of the brushless motor away from the fan blade  612  into the brushless motor. Then the wind is discharged from the gap between the brushless motor and the recessed part  22  of the middle cover assembly  2 , which means that the cooling wind enters the brushless motor along the direction C, and then exits along the direction D, so that heat is dissipated from the brushless motor. In other embodiments, the fan blade  612  is also capable of being arranged at the end of the brushless motor away from the impeller  62 , the cooling wind is introduced into the brushless motor along the direction C, and then discharged along the direction D. Or the cooling wind enters the brushless motor along the opposite direction of the direction D, and then exits along the opposite direction of the direction C. 
     The rated rotating speed of the impeller  62  is set between 20,000 rpm to 80,000 rpm, and the diameter of the impeller  62  is set between 60 mm and 90 mm. With this arrangement, the total pressure efficiency of the vacuum cleaner  100  is relatively high, so that the dust suction efficiency of the vacuum cleaner  100  can be improved. The rotating speed of the impeller  62  may also be greater than 80,000 rpm, and the diameter of the impeller  62  may be less than 60 mm or greater than 90 mm, which is not a limited herein. Preferably, the diameter of the impeller  62  is between 60 mm to 80 mm. When the rated rotating speed of the impeller  62  is set to 40,000 rpm, and the diameter of the impeller  62  is set to 70 mm, the impeller  62  has the highest total pressure efficiency at this time. Preferably, the diameter of the impeller  62  is set to 60 mm. With this arrangement, when the rotating speed of the impeller  62  is between 20,000 rpm to 80,000 rpm, the vacuum cleaner  100  has better total pressure efficiency, so that the fan suction assembly  6  is capable of being applied widely. 
     Please refer to  FIG.  2    and  FIG.  10   , the filter assembly  4  includes a filter element  41 . The filter element  41  is fixedly arranged in the dust collection cavity  13  formed by the dust collector  1  and the middle cover assembly  2 , located below the impeller  62 , and communicates with the through hole  221  in the bottom wall of the recessed part  22  of the middle cover assembly  2 , so that when the impeller  62  rotates, the filtered gas will be sucked into the impeller  62  and a high-pressure airflow is formed at the top of the impeller  62 , which makes the high-pressure airflow flows out along the spiral air channel  631  inside the fan housing. Since the specific structure of the filter assembly  4  can adopt conventional technical solutions, it will not be repeated here. 
     In summary, the air flow direction of the vacuum cleaner  100  of the disclosure is: the air flow carries impurities into the dust collector  1  through the dust suction accessory  52 , the throat pipe  51  and the air inlet  30 . After filtered by the filter assembly  4 , the impurities will fall into the dust collector  1 . The air flow continues to flow along the spiral air channel  631  in the fan housing, so that when the motor  61  rotates, the impeller  62  can be driven to rotate and a high-pressure air flow can be formed at the top of the impeller  62 . Then the high-pressure air flows out from the air outlet 30′ along the spiral air channel  631  in the fan housing. The spiral air channel  631  is beneficial to reduce wind pressure loss and wind resistance, improves air flow, and improves suction effect and working efficiency of the vacuum cleaner  100  to a certain extent. 
     The above embodiments are only used to illustrate the technical solutions of the disclosure and not to limit them. Although the disclosure has been described in detail with reference to preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the disclosure can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the disclosure.