Patent Publication Number: US-2017353095-A1

Title: Driving Device And Bladeless Fan Utilizing the Same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Application No. 201610394996.8 filed in The People&#39;s Republic of China on Jun. 3, 2016. 
     FIELD OF THE INVENTION 
     The present invention relates to the field of motor driving, and in particular to an improved driving device and a bladeless fan utilizing the driving device. 
     BACKGROUND OF THE INVENTION 
     Currently, motor driving has becoming an indispensable driving manner in people&#39;s daily lives. Traditionally, relevant parts driven by motors to move are manly driven through integrated gearboxes in a mechanical manner. This driving manner causes issues such as mechanical friction, wear and noise. This driving manner cannot meet needs required by low-noise apparatuses such as bladeless fans. In addition, a large number of components are used in the traditional design, which makes fabrication of the driving device more complicated. 
     SUMMARY OF THE INVENTION 
     Thus, there is a desire for an improved driving device and a bladeless fan utilizing the driving device. 
     A driving device configured to drive a rotary body includes a motor assembly. The driving device further includes a magnetic member disposed on the rotary body along a circumferential direction thereof. A side of the magnetic member facing the motor assembly forms a plurality of magnetic poles. Upon rotation of the motor assembly, the magnetic member is driven by magnetic interaction between the motor assembly and the magnetic member to thereby drive the rotary body to rotate. 
     Preferably, the magnetic member is a magnetic ring magnetized to have multiple N-polarities and S-polarities arranged alternatively along a circumferential direction of the magnetic ring. 
     Preferably, the magnetic member includes a plurality of first magnets arranged along the circumferential direction of the rotary body, and surfaces of the first magnets away from the rotary body have N-polarities and S-polarities alternatively arranged along a circumferential direction of an annular wall of the rotary body. 
     Preferably, the rotary body comprises an annular wall, the magnetic member is mounted on the annular wall, and a side of the magnetic member away from the annular wall has N-polarities and S-polarities alternatively arranged along a circumferential direction of an annular wall. 
     Preferably, the motor assembly includes a motor and a second magnet connected to the motor, the second magnet includes a first semi-cylinder and a second semi-cylinder, a circumferential surface of the first semi-cylinder and a circumferential surface of the second semi-cylinder have opposite polarities, the second magnet is accommodated in the rotary body and is offset from a center of the rotary body, the magnetic member is disposed between the rotary body and the second magnet, and an axis of the second magnet is parallel to an axis of the annular wall. 
     Preferably, the motor is a single-phase brushless direct current motor, a multi-phase brushless direct current motor, a step motor or a synchronous motor. 
     Preferably, the motor assembly is a permanent magnet motor which includes a stator and a rotor having a plurality of permanent magnets, and the rotary body rotates under magnetic interaction between the plurality of permanent magnets and the magnetic member. 
     Preferably, the permanent magnet motor is an outer-rotor unidirectional permanent magnet motor. 
     A bladeless fan includes the driving device described above. The bladeless fan includes a base, a pressurizer, and a nozzle. One end of the rotary body is rotatably connected to the base. The motor assembly is mounted to the base. The nozzle is connected to one end of the rotary body away from the base. The driving device is configured to drive the rotary body to rotate relative to the base, and the pressurizer is configured to suck and pressurize air such that the pressurized air is ejected out via the nozzle. 
     Preferably, the base has an accommodating space, and the pressurizer is mounted in the accommodating space. 
     Preferably, a tray protrudes from the base in an interior thereof, and the motor assembly is mounted on the tray. 
     Preferably, the rotary body has an accommodating chamber, and the pressurizer is mounted in the accommodating chamber. 
     Preferably, the motor assembly is mounted at a bottom of the base. 
     Preferably, a circumferential wall of the base defines a plurality of air inlets. 
     Preferably, the bladeless fan further includes a conducting wire disposed at the base. 
     In the driving device of embodiments of the present invention, the rotary body rotates under the magnetic interaction between the motor assembly and the magnetic member. This contactless magnetic driving manner results in lowered noise. In addition, the bladeless fan of embodiments of the present invention realizes contactless magnetic driving by using this driving device and, therefore, the noise is lowered as the rotary body rotates relative to the base. Furthermore, using this driving device reduces cost and facilitates the fabrication thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a bladeless fan in accordance with a first embodiment of the present invention. 
         FIG. 2  illustrates a driving device and a rotary body shown in  FIG. 1 . 
         FIG. 3  illustrates the driving device and the rotary body shown in  FIG. 1 , viewed from another aspect. 
         FIG. 4  illustrates the driving device and rotary body in accordance with another embodiment of the present invention. 
         FIG. 5  illustrates a bladeless fan in accordance with a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The technical solutions of the embodiments of the present invention will be clearly and completely described as follows with reference to the accompanying drawings. Apparently, the embodiments as described below are merely part of, rather than all, embodiments of the present invention. Based on the embodiments of the present invention, any other embodiment obtained by a person skilled in the art without paying any creative effort shall fall within the protection scope of the present invention. 
     It is noted that, when a component is described to be “fixed” to another component, it can be directly fixed to the another component or there may be an intermediate component. When a component is described to be “connected” to another component, it can be directly connected to the another component or there may be an intermediate component. When a component is described to be “disposed” on another component, it can be directly disposed on the another component or there may be an intermediate component. 
     Unless otherwise specified, all technical and scientific terms have the ordinary meaning as commonly understood by people skilled in the art. The terms used in this disclosure are illustrative rather than limiting. The term “and/or” used in this disclosure means that each and every combination of one or more associated items listed are included. 
       FIG. 1  illustrates a bladeless fan  100  in accordance with one embodiment of the present invention. The bladeless fan  100  is configured to suck air, pressurize the sucked air, and eject the pressurized air to generate an airflow desired by a user. The bladeless fan  100  includes a base  10 , a driving device  20 , a rotary body  30 , a nozzle  40 , and a pressurizer  50 . One end of the rotary body  30  is connected to the nozzle  40 . At a connection area between the rotary body  30  and the nozzle  40 , a flow conduit is mounted, which is in communication with the nozzle  40  and the pressurizer  50 . The driving device  20  is configured to drive the rotary body  30  to rotate any angle in the range of 0 to 360 degrees about the base  10 . 
     The base  10  is generally in the form of a hollow circular cylinder which defines an accommodating space  11 . A circumferential wall of the base  10  defines a plurality of air inlets  12  in communication with the accommodating space  11 . 
     Referring also to  FIG. 2  and  FIG. 3 ,  FIG. 2  and  FIG. 3  illustrate positional relationship between the driving device  20  and rotary body  30 , viewed from different aspects. The driving device  20  includes a motor assembly  21  and a plurality of first magnets  22 . In this embodiment, the motor assembly  21  includes a motor  211  and a second magnet  212  connected to the motor  211 . The motor  211  includes a rotary shaft  2111 . The rotary shaft  2111  has one end extending out of the motor  211  and connected to the second magnet  212 . The second magnet  212  is cylindrical, which includes a first semi-cylinder  2121  and a second semi-cylinder  2122 . A circumferential surface of the first semi-cylinder  2121  and a circumferential surface of the second semi-cylinder  2122  have opposite polarities. In this embodiment, the circumferential surface of the first half-cylinder  2121  has N-polarity, while the circumferential surface of the second semi-cylinder  2122  has S-polarity. 
     The motor  211  is mounted within the base  10 . In this embodiment, a tray  13  protrudes from the base  10  in an interior thereof. The motor  211  is mounted on the tray  13 . The motor  211  may be a brushless direct current motor (single-phase or multi-phase), a step motor or a synchronous motor. 
     One end of the rotary body  30  is connected to the nozzle  40 , and the other end is connected to the base  10 . In this embodiment, the rotary body  30  is generally in the form of a hollow cylindrical structure, which includes an annular wall  31  and a connecting wall  32 . The annular wall  31  and the connecting wall  32  cooperatively define an accommodating chamber  33 . The multiple first magnets  22  are arranged circumferentially about the annular wall  31  and, in particular, are mounted to an inner side of the annular wall  31  at even intervals. In this embodiment, the first magnets  22  are also disposed at one end of the annular wall  31  adjacent the base  10 . In this embodiment, each first magnet  22  is generally rectangular in shape and is polarized along a circumferential direction of the annular wall  31 . As such, each first magnet  22  forms one magnetic pole, and the polarities of adjacent first magnets  22  are opposite to each other. Specifically, the multiple first magnets  22  are arranged along a circumferential direction of the annular wall  31 , and surfaces of the first magnets  22  facing a center of the rotary body  30  have N-polarities and S-polarities alternatively arranged along the circumferential direction of the annular wall  31 , such that a plurality of alternatively arranged N-polarities and S-polarities is formed along an inner circumferential surface of the annular wall  31 . 
     In this embodiment, the second magnet  212  is accommodated in the accommodating chamber  33  and offset from a center of the annular wall  31 , with the first magnets  22  disposed between the annular wall  31  and the second magnet  212 , and an axis of the second magnet  212  parallel to an axis of the annular wall  31 . 
     As the motor  211  operates to drive the rotary shaft  2111  to rotate, the rotary shaft  2111  in turn drives the second magnet  212  to rotate. Under the magnetic force of the first magnets  22  and the second magnet  212 , the multiple first magnets  22  are driven to move, thereby driving the rotary body  30  and the nozzle  40  to rotate, such that the pressurized air is ejected through different angles. Referring also to  FIG. 4 ,  FIG. 4  illustrates the driving device  20  according to another embodiment. In this embodiment, the motor assembly  21  does not include the second magnet  212  and is a permanent magnet motor. Preferably, the permanent magnet motor is an outer-rotor unidirectional permanent magnet motor, which includes a stator  213  and a rotor having a plurality of permanent magnets  214 . The stator  213  is disposed within the rotor. The multiple permanent magnets  214  rotate about the stator  213 . The rotary body  30  is rotated by the magnetic force of the permanent magnets  214  and the first magnets  22 . The motor assembly  21  of this embodiment eliminates the second magnet  212  which reduces the manufacturing cost. In addition, the rotary body  30  is driven to rotate by the magnetic force of the permanent magnets  214  of the motor  211  and the first magnets  22 , thereby reducing an axial length of the driving device  20 . 
     The nozzle  40  is generally annular, which includes an air passage  41  formed in an interior of the nozzle  40  along a circumferential direction of the nozzle  40 . One end of the air passage  41  is in communication with outside air, and the other end is in communication with the pressurizer  50 . The air passage  41  is used to deliver the airflow. It should be understood that, in other embodiments, the nozzle  40  may be rectangular, triangular, or polygonal in shape. 
     In this embodiment, the accommodating space  11  of the base  10  is greater than the accommodating chamber  33  of the rotary body  30  in volume. 
     The pressurizer  50  is mounted within the accommodating space  11  and includes a pressurizer motor  51  and a plurality of flow passages  52 . The air inlets  12  are in communication with an inlet end (not shown) of the pressurizer  50 , the flow passages  52 , an outlet end (not shown) of the pressurizer  50 , and the nozzle  40 . The pressurizer motor  51  operates to suck air into the flow passages  52  via their respective air inlets  12 . The sucked air is pressurized by the pressurizer motor  51 , discharged to the air passage  41  via the flow passages  52 , and ejected to the outside environment from the bladeless fan  100  via the air passage  41  of the nozzle  40 . 
     The bladeless fan  100  further includes a conducting wire  60  for connecting with an external power supply (not shown). The conducting wire  60  is used to supply power to the motor  211  of the driving device  20  and the pressurizer motor  51  of the pressurizer  50 , thereby avoiding tangle of the conducting wire  60  during operation of the bladeless fan  100 . Specifically, the pressurizer motor  30  and the motor  211  of the driving device  20  are both mounted within the base  10 , the conducting wire  60  passes through the base  10  to supply power to the pressurizer motor  30  and the motor  211  of the driving device  20 . The base  10  does not rotate during operation of the bladeless fan  100 , such that the conducting wire  60  is in static state and avoids a tangle issue. 
     In the bladeless fan  100  of the present invention, the rotary body  30  is rotated by the magnetic force of the first magnets  22  of the driving device  20  and the second magnet  212 . This contactless magnetic driving manner results in lowered noise during rotation of the rotary body  30  relative to the base  10 . In addition, in comparison with the conventional mechanical driving manner such as gear driving, the driving device  20  using the magnetic force has a simple structure and low cost and is convenient to fabricate. The bladeless fan  100  using the driving device  20  of the present invention has reduced weight and volume and prolonged lifespan in comparison with the conventional fans. In addition, because the contactless magnetic driving manner is used, no wear is generated during the driving course, which leads to a more even rotation speed. It should be understood that a rotation direction of the rotary body  30  can be adjusted by controlling a rotation direction of the motor  211 . 
     It should be understood that a swing angle of the rotary body  30  can be set by controlling a rotation angle of the motor  211  using a timer. 
     It should be understood that a rotation speed of the rotary body  30  can be adjusted by controlling the motor  211  using, for example, PWM control signals. 
     It should be understood that the multiple first magnets  22  may be replaced by a magnetic ring magnetized to have a plurality of magnetic poles. The magnetic ring, after magnetized, has multiple N-polarities and S-polarities arranged alternatively along a circumferential direction of the magnetic ring. 
     Referring to  FIG. 5 ,  FIG. 5  is a plan view of a bladeless fan  100   a  in accordance with a second embodiment of the present invention. This embodiment differs from the first embodiment in that, the accommodating space  11   a  of the base  10   a  is less than the accommodating chamber  33   a  of the rotary body  30   a  in volume, the pressurizer  50   a  is disposed within the accommodating chamber  33   a  of the rotary body  30   a,  and the motor  211   a  of the driving device  20   a  is mounted at a bottom of the base  10   a.    
     The above embodiments are merely to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described with reference to the above preferred embodiments, it should be appreciated by those skilled in the art that various modifications and variations may be made without departing from the spirit and scope of the present invention.