Patent Publication Number: US-2020283148-A1

Title: Spraying apparatus and unmanned aerial vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of International Application No. PCT/CN2017/114029, filed Nov. 30, 2017, the entire content of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The disclosure relates to the field of agricultural operations, in particular to a spraying apparatus and an unmanned aerial vehicle. 
     BACKGROUND 
     With continuous development of technology, more and more automatic control equipment is used in agricultural operations. 
     At present, in order to spray chemical solution such as pesticides on crops, the chemical solution can be sprayed in a centrifugal manner by an automatic nozzle. Specifically, the automatic nozzle includes a rotor shaft and a spin plate that can be driven by the rotor shaft. After entering the spin plate through an internal channel, the chemical solution can be dispersed outward in a mist under the centrifugal force of the spin plate that is rotating at a high speed, to achieve a uniform spray effect. In order to supply chemical solution to the spin plate, the liquid can be introduced into the plate by a driving mechanism or from a side of the driving mechanism so that the chemical solution can flow into the spin plate from an internal space of the driving mechanism or the side of the driving mechanism. 
     However, due to corrosion of the chemical solution and rotation mechanism wear-out, components such as coil windings in the driving mechanisms are more likely to be damaged. When the nozzle adopts the method of introducing the chemical solution from the inside of the driving mechanism, the structure of the nozzle is more complicated. When the nozzle adopts the method of introducing the chemical solution from the side of the driving mechanism, the nozzle is usually an integrated structure and is not easy to disassemble, which causes inconvenience to disassemble the nozzle and is not conducive to repair and replacement of the nozzle. 
     SUMMARY 
     In accordance with the disclosure, there is provided a spraying apparatus. The spraying apparatus includes a driving mechanism having a driving shaft rotatable around its own axis and a spin plate disposed at a bottom of the driving shaft. The spin plate is configured to rotate with the driving shaft to spray chemical solution. The driving mechanism includes a stator assembly, a rotor assembly and a housing assembly. The housing assembly includes a first housing member and a second housing member. The first housing member and the stator assembly are connected; the rotor assembly is connected to the second housing member; the first housing member is connected to the second housing member by snap-fit; and a bottom side of the second housing member is provided with a water inlet pipe that is connected to an internal of the spin plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to more clearly explain the embodiments of the present disclosure or the technical solutions in the prior art, the following will briefly introduce the drawings used in the embodiments or the description of the prior art. Obviously, the drawings in the following description are some embodiments of the present disclosure. For those of ordinary skilled in the art, other drawings can also be obtained based on these drawings without any creative efforts. 
         FIG. 1  is an exploded schematic view of a spraying apparatus according to an embodiment of the present disclosure; 
         FIG. 2  is a schematic cross-sectional view of the spraying apparatus according to an embodiment of the present disclosure; 
         FIG. 3  is a schematic structural diagram of a stator assembly in the spraying apparatus according to an embodiment of the present disclosure; 
         FIG. 4  is a schematic structural diagram of a first housing member in a spraying apparatus according to an embodiment of the present disclosure; 
         FIG. 5  is a schematic structural diagram of a second housing member in the spraying apparatus according to an embodiment of the present disclosure; 
         FIG. 6  illustrates a side view of the second housing member in the spraying apparatus according to according to an embodiment of the present disclosure; 
         FIG. 7  illustrates a top view of the second housing member in the spraying apparatus according to an embodiment of the present disclosure; and 
         FIG. 8  illustrates a cross-sectional view taken along A-A in  FIG. 7 . 
     
    
    
     REFERENCE NUMERALS 
       1 —driving mechanism;  2 —spin plate;  3 —mounting base;  11 —stator assembly;  12 —rotor assembly;  13 —first housing member;  14 —second housing member;  31 —sleeve part;  32 —thread fastener;  111 —stator base;  112 —winding;  121 —rotor shaft;  122 —rotor cover;  131 —annular cavity;  132 —first snap slot;  133 —second protrusion;  141 —hollow cavity;  142 —through hole;  143 —inlet channel;  144 —annular cavity;  145 —first protrusion;  132   a —opening section;  132   b —snap section;  1111 —second snap slot. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be described clearly and completely in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are a part of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without creative efforts fall within the scope of the present disclosure. 
       FIG. 1  is an exploded schematic view of a spraying apparatus according to an embodiment of the present disclosure.  FIG. 2  is a schematic cross-sectional view of the spraying apparatus according to an embodiment of the present disclosure.  FIG. 3  is a schematic structural diagram of a stator assembly in the spraying apparatus according to an embodiment of the present disclosure.  FIG. 4  is a schematic structural diagram of a first housing member in a spraying apparatus according to an embodiment of the present disclosure.  FIG. 5  is a schematic structural diagram of a second housing member in the spraying apparatus according to an embodiment of the present disclosure.  FIG. 6  illustrates a side view of the second housing member in the spraying apparatus according to according to an embodiment of the present disclosure.  FIG. 7  illustrates a top view of the second housing member in the spraying apparatus according to an embodiment of the present disclosure.  FIG. 8  illustrates a cross-sectional view taken along A-A in  FIG. 7 . As shown in  FIGS. 1 to 8 , the spraying apparatus according to the embodiments of the disclosure includes a driving mechanism  1  having a driving shaft rotatable around its own axis, and a spin plate  2  disposed at a bottom of the driving shaft. The spin plate  2  is configured to be driven by the rotation shaft to rotate and spray chemical solution. The driving mechanism  1  includes a stator assembly  11 , a rotor assembly  12 , and a housing assembly. The housing assembly includes a first housing member  13  and a second housing member  14 . The first housing member  13  is connected to the stator assembly  11 . The rotor assembly  12  is received in the second housing member  14 , and the first housing member  13  is connected to the second housing member  14  by a snap-fit, and a water channel connected to the spin plate  2  is disposed at a bottom side of the second housing member  14 . 
     Specifically, the spraying apparatus is mainly configured to spray the chemical solution around uniformly by the centrifugal force during rotation, so as to achieve the purpose of uniformly spraying the chemical solution. In order to centrifuge the chemical solution, the spraying apparatus includes the driving mechanism  1  capable of driving the spin plate to rotate. The driving mechanism  1  includes a driving shaft that can rotate around its own axis. The spin plate  2  is located at the bottom of the driving shaft, so that when the driving shaft rotates, it can drive the spin plate  2  to rotate synchronously to spray the chemical solution around. 
     In order to drive the spin plate  2  to rotate, the driving mechanism  1  includes the stator assembly  11 , the rotor assembly  12 , and the housing assembly configured to fix the stator assembly  11  and the rotor assembly  12 . The housing assembly is a split structure, which includes the first housing member  13  and the second housing member  14 . The first housing member  13  and the second housing member  14  can be connected to the stator assembly  11  or the rotor assembly  12 , respectively, and the connection the first housing member  13  and the second housing member  14  is detachable snap-fit. As such, the stator assembly  11  and the rotor assembly  12  are respectively disposed on corresponding parts of the housing assembly, so that by separating the first housing member  13  and the second housing member  14 , the stator assembly  11  and the rotor assembly  12  in the driving mechanism  1  can be relatively disassembled from each other to facilitate the repair and replacement of the stator assembly  11  and the rotor assembly  12  respectively. 
     In order to prevent the driving mechanism from being corroded by the chemical solution, a water inlet pipe for the circulation of the chemical solution is disposed on bottom side of the second housing member  14  so that the water inlet pipe is located outside the stator assembly  11  and the rotor assembly  12 . Accordingly, the chemical solution is isolated from the driving mechanism  1  and does not enter the driving mechanism  1  to cause corrosion to the driving mechanism  1 . The overall corrosion resistance and reliability of the spraying apparatus are high. 
     Therefore, by disposing the stator assembly  11  and the rotor assembly  12  of the drive mechanism  1  on the first housing member  13  and the second housing member  14  respectively, a modular stator assembly  11  and rotor assembly  12  can be formed, to make it convenient to disassemble and install the spraying apparatus while simplifying an overall structure of the apparatus. At the same time, the water inlet pipe configured to connect the spin plate  2  is disposed at the bottom side of the housing assembly, so that the passage of the chemical solution is not connected to the internal of the driving mechanism  1 , and the whole apparatus has high corrosion resistance and reliability. 
     In order to facilitate quick disassembly between the first housing member  13  and the second housing member  14 , as an optional connection method, the first housing member  13  and the second housing member  14  can rotate to snap-in. As such, after the first housing member  13  and the second housing member  14  are being located at preset relative positions, the first housing member  13  and the second housing member  14  can rotate relative to each other to achieve the snap-fit or release of the snap-fit of the first housing member  13  and the second housing member  14 . In this way, the engagement can be completed by a simple operation, and the engagement process can be relatively simple. 
     Generally, in the driving mechanism  1 , especially the stator assembly  11  is usually provided with coil windings and other electrical components. In order to avoid the influence of the chemical solution entering the spin plate  2  through the water inlet pipe on the coil windings and so forth, the water inlet pipe may generally be located below the stator assembly  11 . As such, a height of the stator assembly  11  is greater than a height of the water inlet pipe, and even if the chemical solution flows to an underneath of the stator assembly  11 , it can flow downward due to gravity and cannot reach the stator assembly  11  located above, so that the stator assembly  11  cannot be corroded by the chemical solution, to increase the safety and reliability of the apparatus. 
     In order to dispose the stator assembly  11  and the rotor assembly  12  separately, and realize the detachable snap-fit at the same time, the first housing member  13  and the second housing member  14  in the housing assembly respectively may have a variety of possible structures and implementations. Specific illustrations are as below. 
     As an optional embodiment, the second housing member  14  may have a hollow cavity  141  with an open top, and the rotor assembly  12  is disposed in the hollow cavity  141 . At this time, the rotor assembly  12  is occupied by the hollow cavity  141 , and thus is protected by the second housing member  14 . In addition, since the rotor assembly  12  is supported by the hollow cavity  141 , the connection and fixation between the rotor assembly  12  and the second housing member  14  can also be implemented. A shape of the hollow cavity  141  can generally match an outer shape of the rotor assembly  12  so that the rotor assembly  12  can be steadily placed in the second housing member  14 . 
     Optionally, the rotor assembly  12  generally includes a rotor shaft  121  and a rotor cover  122  connected to the rotor shaft  121 . An axis of the rotor shaft  121  coincides with an axis of the driving shaft. The rotor shaft  121  can be connected to the spin plate  2  as a main body of the driving shaft to drive the spin plate  2  to rotate around the axis of the rotor shaft  121 , and the rotor cover  122  is configured to be coupled to the stator assembly  11  to drive the rotor shaft  121  to rotate under an electromagnetic force between the stator assembly. Generally, the rotor cover  122  may surround an outside of the rotor shaft  121 , a lower portion of the rotor cover  122  may be connected to the rotor shaft  121 , and an upper portion of the rotor cover  122  may be spaced from the rotor shaft  121  and have an upward opening configured to receive a corresponding part of the stator assembly  11 . 
     In addition, optionally, the rotor assembly  12  further includes at least one of a magnet and a magnetic yoke. The magnet and the magnetic yoke can generate a magnetic field force, and a power that drives the rotor assembly  12  to rotate may be generated under an action between the magnet and the stator assembly  11 . Generally, the magnet and magnetic yoke in the rotor assembly  12  are usually correspondingly disposed on the rotor cover  122 . 
     Further, in order to cause the rotor shaft  121  of the rotor assembly  12  to be easily connected to the spin plate, a through hole  142  may be disposed at the bottom surface of the second housing member  14 , the rotor cover  122  may be disposed in the hollow cavity  141 , and a bottom end of the rotor shaft  121  may pass through the through hole  142 . In this way, the rotor shaft  121  can protrude from a bottom of the second housing member  14  and be connected to the spin plate  2  below. Since the rotor assembly  12  may rotate relative to the stator assembly  11 , bearings may be disposed at a connection portion between the second housing member  14  and the rotor assembly  12  to cause the rotor assembly  12  to rotate freely relative to the second housing member  14 . 
     Because the bottom end of the rotor shaft  121  is generally directly connected to the spin plate  2 , and a hollow channel of the spin plate  2  receives the chemical solution for spraying, when the spin plate  2  is driven by the rotor shaft  121 , the chemical solution may stick to an outer circumferential surface of the rotor shaft  121  due to its own viscosity, and move upwards with the rotor shaft  121 , and splash into the internal of the driving mechanism  1 . In order to prevent the chemical liquid from moving upward with the rotation of the rotor shaft  121 , a spiral structure with the rotor shaft  121  as a rotation axis may be disposed at the outer circumferential surface of the rotor shaft  121 , and a rotation direction of the spiral structure is opposite to a rotation direction of the driving shaft. Accordingly, when the chemical solution has a trend to ascend with the rotation of the rotor shaft  121 , the spiral structure may block a forward path of the chemical solution, thereby preventing the chemical solution from continuing to move upward. At the same time, the chemical solution blocked by the spiral structure may also follow the spiral structure and fall to the bottom of the rotor shaft  121  in a spiral manner without being accumulated on the outer circumferential surface of the rotor shaft  121 . 
     Generally, the spiral structure may be a spiral protrusion wound on the outer circumferential surface of the rotor shaft  121 , or a spiral groove disposed on the outer circumferential surface of the rotor shaft  121 . In addition, the spiral structure may also be other structure familiar to a person skilled in the art and will not be repeated here. 
     In order to supply the chemical solution to an internal of the spin plate  2 , optionally, the second housing member  14  may be provided with a water inlet pipe  143 . An inlet of the water inlet pipe  143  may be located on a side of the second housing member  14 , and an outlet of the water inlet pipe  143  is located at the bottom of the second housing member  14  and has the same height with the through hole  142 . The outlet and the through hole  142  are isolated from each other. Accordingly, since the outlet of the water inlet pipe  143  is located at the bottom of the second housing member  14  and is isolated from the through hole  142  and the hollow cavity  141  in the second housing member  14 , so that the chemical solution can be effectively isolated from the rotor assembly  12  disposed inside the hollow cavity  141  to prevent the rotor assembly  12  from being corroded by the chemical solution. 
     In order to cause the chemical solution to pass through the spin plate  2  in a circumferential direction, the bottom of the second housing member  14  is also provided with a annular cavity  144  connected the outlet. The annular cavity  144  is wound around an outside of the through hole  142 . Accordingly, after the chemical solution flows into the annular cavity  144  from the outlet of the water inlet pipe  143 , it can fill each area in the annular cavity  144  and flow from the annular cavity  144  to all circumferential directions of the spin plate  2 , so that the chemical solution can be sprayed outward in the circumferential direction of the spin plate  2 . 
     Further, a width of the annular cavity  144  on the side close to the outlet may generally be smaller than a width on a side farther from the outlet. Accordingly, a size of the annular cavity  144  on the side near the outlet is smaller than a size on the side far from the outlet, so that the size of the annular cavity  144  may counteract the difference in flow rate caused by the different distances between itself and the outlet, so that the chemical solution can flow more uniformly to ensure that the chemical solution is evenly distributed in all circumferential directions of the spin plate  2 . 
     In order to achieve a snap-fit with the first housing member  13 , an outer periphery of the second housing member  14  may be a revolving surface, and at least one first protrusion  145  configured to snap-in the first housing member  13  is disposed at the second housing member  14 . Accordingly, the second housing member  14  may be disposed inside or in the internal of the first housing member  13  and snap-in the first housing member  13  by rotation. In order to ensure uniform stress with the first housing member  13 , the number of the first protrusions  145  is usually plural. 
     Since the first housing member  13  may receive the second housing member  14 , accordingly, the first housing member  13  can have an annular cavity  131  for receiving the stator assembly  11  and the rotor assembly  12 . At this time, not only the stator assembly  11  may be received in the first housing member  13  but also the rotor assembly  12  may be at least partially received inside the first housing member  13 . 
     Further, an inner wall of the annular cavity  131  is provided with a first snap slot  132  configured to snap-in the first protrusion  145 . At this time, the second housing member  14  may be received inside the annular cavity  131 , and the first protrusion  145  and the first snap slot  132  may be connected to each other by snap-fit to fix the second housing member  14  to the internal of the annular cavity  131  of the first housing member  13 . 
     In order to achieve the snap-fit connection between the first housing member  13  and the second housing member  14  in all circumferential directions, the number of the first snap slots  132  is at least two, and the first snap slots  132  and the first protrusions  145  correspond to each other. Accordingly, through the connection between the plurality of first snap slots and the first protrusions, force received by the single first protrusion  145  and the first snap slot  132  can be dispersed, while the plurality of first snap slots  132  and the first protrusions  145  distributed in different positions can receive uniform force with certainty, to avoid the phenomenon that a friction between the single first protrusion  145  and the first snap slots  132  is so great that they cannot be disassembled or even the snap-fit structure can be damaged. Generally, the first snap slot  132  and the first protrusions  145  can be arranged at even intervals around the circumference of the driving shaft. 
     In order to simplify the snap-in process between the first housing member  13  and the second housing member  14 , the first housing member  13  and the second housing member  14  are usually connected in a rotating snap-in manner. Therefore, in order to achieve rotational engagement between the two, the first snap slot  132  is usually a rotating snap slot. As such, the first protrusion  145  can complete the entire engagement process by snapping and rotating with the first engaging slot  132 , and the entire engagement process is relatively simple. 
     Specifically, when the first snap slot  132  is a rotating snap slot, the first snap slot  132  may include an opening section  132   a  opened toward the bottom of the annular cavity  131  and a snap section  132   b  connected to the opening section  132   a . The snap section  132   b  extends along a circumferential direction of the annular cavity  131 , and the snap section  132   b  is configured to snap-in the first protrusion  145  that enters the first engaging slot  132  through the opening section  132   a  in an axial direction of the rotor shaft  1  when the first housing member  13  and the second housing member  14  rotate relative to each other. As such, when the first protrusion  145  engages with the first snap slot  132 , the first protrusion  145  can first enter the first snap slot  132  through the opening section  132   a , then the first housing member  13  and the second housing member  14  may rotate relative to each other so that the first protrusion  145  moves along the snap section  132   b  of the first snap slot  132  to the internal of the first snap slot  132 . Accordingly, the snap section  132   b  of the first snap slot  132  can engage with two sides of the first protrusion  145 , to prevent the first protrusion  145  from detaching from the first snap slot  132 , and to ensure that the first housing member  13  and the second housing member  14  are in a mutually engaged position. Generally, an engagement protrusion structure is usually disposed at the end of the snap section  132   b , or a relatively large friction force exists between the end of the snap section  132   b  and the first protrusion  145 , to prevent the first protrusion  145  from detaching from the first snap slot  132  along the snap section  132   b  in a reverse direction. 
     Optionally, in order to connect the first protrusion  145  and the first snap slot  132  to the first housing member  13  and the second housing member  14  by snap-fit in the axial direction of the driving shaft, in the first snap slot  132 , an extending direction of the opening section  132   a  is along the axial direction of the driving shaft, and an extending direction of the snap section  132   b  is perpendicular to the axial direction of the driving shaft. As such, a wall of the snap section  132   b  can be disposed on the side of the first protrusion  145  to prevent the first housing member  13  and the second housing member  14  from being separated from each other in the axial direction of the driving shaft. Accordingly, by taking advantage of the snap-fit between the first protrusion  145  and the first snap slot  132 , the second housing member  14  can be fixed on the first housing member  13  to prevent the second housing member  14  from separating from the first housing  13  in the axial direction. 
     Generally, a size of the opening section  132   b  generally matches a size of the first protrusion  145 . For example, the size of the opening section  132   b  may be slightly larger than the size of the first protrusion  145 , thereby facilitating the first protrusion  145  to enter the first snap slot  132 , and meanwhile preventing the first protrusion  145  from detaching from the first snap slot  132 . 
     Optionally, the first housing member  13  may have various shapes, for example, as an optional embodiment, the first housing member  13  may be a ring-shaped body. As such, the first housing member  13  has a relatively simple shape and a simple structure, and the cost is low. 
     When the first housing member  13  is a ring-shaped body, since the first housing member  13  and the second housing member  14  are usually engaged in a rotation manner, in the engagement process, the first housing member  13  and the second housing member  14  may rotate relative to each other. Accordingly, as an optional structure, the outer circumferential surface of the first housing member  13  may be provided with anti-skid patterns or anti-skid protrusions. When a user needs a rotating snap, he can conveniently hold the outer circumferential surface of the first housing member  13  so that the first housing member  13  can be engaged with the second housing member  14  or the engaged state of the two can be released. 
     Alternatively, in order to improve the disassembly/assembly speed and convenience of the spraying apparatus, the stator assembly  11  and the first housing member  13  are usually connected by snap-fit. The snap-fit connection enables the stator assembly  11  to be quickly and easily dissembled from the first housing member  13 , thereby achieving rapid separation of the components. 
     Specifically, the stator assembly  11  may include a plurality of component parts such as a stator base  111 . The stator base  111  may be used as a main structural component in the stator assembly  11  configured to set other components in the stator assembly  11 . At this time, the stator base  111  in the stator assembly  11  and the first housing member  13  can be engaged with each other. 
     As one of the optional snap-fit methods, one of the first housing member  13  and the stator base  111  may be provided with a second snap slot, and the other is provided with a second protrusion that can snap in the second snap slot. Accordingly, the first housing member  13  and the stator base  111  can be connected by the snap-fit between the second protrusion and the second snap slot. 
     In order to reduce the volume and weight of the first housing member  13 , the first housing member  13  is usually a thin-shell type component. At this time, the second protrusion  133  may be disposed on a top of the first housing member  13 , and the second snap slot  1111  configured to be connected to the second protrusion  133  by snap-fit may be disposed on a periphery of the stator base  111 . As such, the first housing member  13  does not need to be provided with a snap slot, so the first housing member  13  can have a thin wall, thereby effectively reducing its weight and volume. Meanwhile, because a lower part of the stator base  111  is usually provided with other components configured to be engaged with the rotor assembly  12 , when the second protrusion  133  is disposed on the top of the first housing member  13 , the first housing member  13  can be connected to the stator base  111  and sleeved on the lower half of the stator base  111  through the second protrusion  133 , thereby effectively shielding and protecting other components on the stator base  111 . 
     A protruding direction of the second protrusion  133  may be perpendicular to the axial direction of the rotor shaft  1 . As such, the ends of the second protrusion  133  can be engaged with the second snap slot  1111  along a direction perpendicular to the axis of the rotor shaft  1 . At this time, through the connection between the second protrusion  133  and the second snap slot  1111 , the first housing member  13  may be hung outside the stator base  111 . At the same time, the second housing member  14  may be fixed to the first housing member  13  by snap-fit, so the weight of the entire housing assembly is carried by the stator base  111 . 
     Likewise, similar to the connection between the first protrusion  145  and the first snap slot  132 , in order to cause the stator seat  111  to carry the weight of the housing assembly and the rotor assembly  12  evenly in the circumferential direction, the number of the second protrusion  133  and the second snap slot  1111  are each plural, and the second protrusions  133  and the second snap slot  1111  are evenly arranged along the circumferential direction of the rotor shaft  1 . At this time, the engagement between the plurality of second protrusions and the second snap slot can effectively carry the weight of the housing assembly and the rotor assembly  12  to avoid excessive force between the single second protrusion  133  and the second snap slot  1111  that causes disassembly/assembly difficulties or the damage to the snap-fit structure. 
     In addition, the stator assembly  11  may include components such as windings  112  in addition to the stator base  111 . The winding  112  is generally formed by a coil. When the winding  112  is energized, a directional electromagnetic field can be generated due to a shape of the winding  112 , and the electromagnetic field can push the rotor assembly  12  to rotate. Generally, the winding  112  may be disposed in the lower half of the stator base  111 . 
     Specifically, the winding  112  may be disposed at the bottom of the stator base  111 , and a position of the winding  112  in the axial direction of the driving shaft corresponds to a position of the rotor assembly  12  in the axial direction of the driving shaft. At this time, the position of the winding  112  is opposite to the position of the rotor assembly  12 , so that the electromagnetic field generated by the winding  112  can be just applied to the rotor assembly  12 . The position of the winding  112  may be opposite to a position of the rotor cover  122  in the rotor assembly  12 , and when an assembly of the rotor assembly  12  and the stator assembly  11  is completed, the winding  112  is usually be located between the rotor cover  122  and the rotor shaft  121 . 
     In order to prevent the chemical solution from leaking to the stator assembly  11  through the gap of the housing assembly and corroding the winding  112  in the stator assembly  11  or short-circuiting the coil of the winding  112 , a shielding structure may be disposed outside the winding  112 . Specifically, as an optional method, a spacer may be wrapped outside the winding  112 . The spacer can be sealed outside the winding  112 , and can prevent external chemical solution or other liquid from penetrating the spacer and contacting the winding  112 , thereby further protecting the winding from the influence of the chemical solution. 
     Optionally, in one implementation of the spacer, the outside of the winding  112  may be wrapped with waterproof insulation glue. The waterproof insulation glue can be sealed on the outside of the winding  112  and isolate the winding  112  from the outside, thereby achieving a waterproof sealing effect. In addition, those skilled in the art can understand that in addition to the waterproof insulation glue, the separator can also be other sealing materials that is waterproof and insulating such as a waterproof tape or a foam-like waterproof material, which will not be repeated here. 
     In addition, the stator assembly  11  may also include electronic speed control (ESC) and other components. The ESC may be configured to adjust a rotation speed of the rotor assembly  12  thereby controlling a spraying rate of the chemical solution sprayed by the spin plate  2 . The components such as the ESC may be integrated on the stator assembly  11  to improve the compactness of the spraying apparatus on the one hand and also facilitate the modularization of the stator assembly  11  on the other hand, to achieve the disassembly and replacement of different modules. 
     Generally, the spraying apparatus is usually installed on other devices or systems. Accordingly, the spraying apparatus needs to be connected with other devices and structures through a connection structure. Since the housing assembly is connected to the stator assembly  11  and the rotor assembly  12  is disposed on the second housing member  14  in the housing assembly, the entire spraying apparatus is supported by the stator assembly  11 . At this time, as an optional structure, the spraying apparatus may further include the mounting base  3 , and the mounting base  3  and the stator assembly  11  are detachably connected. As such, the mounting base  3  can be connected to other structures as a connection member. 
     The mounting seat  3  may have a sleeve portion  31  with an open bottom, so that the top of the stator assembly  11  can extend into a hollow cavity of the sleeve portion  31  and be detachably connected to the mounting seat  3 . The connection method between the stator assembly  11  and the mounting base  3  may be screw or snap-fit. 
     Since the entire spraying apparatus is connected to external structures through the mounting base  3 , the connection between the stator assembly  11  and the mounting base  3  needs to bear great weight and vibration. In order to improve the connection reliability between the stator assembly  11  and the mounting base  3 , the mounting seat  3  and the stator assembly  11  are connected by at least one threaded fastener  32 . A threaded fastener can bear larger loads and have higher anti-vibration performance, which can effectively realize the connection between the stator assembly and the mounting seat. In this embodiment, the mounting base  3  and the stator assembly  11  are connected by four threaded fasteners  32 , and the four threaded fasteners  32  are arranged opposite each other on both sides of the mounting base  3  to strengthen the connection with the threaded fastener  32 . 
     Since the top of the stator assembly  11  extends into the hollow cavity of the sleeve portion  31 , an installation direction of the threaded fastener  32  is generally perpendicular to the axial direction of the driving shaft; that is, it is connected through a side wall of the sleeve portion  31  to the stator assembly  11 . 
     Specifically, a first mounting hole may be disposed at the wall of the sleeve portion  31 , and a second mounting hole opposite to the first mounting hole may be disposed at the top of the stator assembly  11 . At this time, the threaded fasteners  32  may simultaneously pass through the first mounting hole and the second mounting hole to be detachably connected to the stator assembly  11  and the mounting base  3 . 
     In addition, the spraying apparatus also includes a swing plate  2  for spraying the chemical solution, and the swing plate  2  and the driving shaft may be detachably connected. Specifically, the connection method between the swing disk  2  and the driving shaft may be a quick release connection method such as a snap-fit. 
     Specifically, the spin plate  2  may be a split structure that is convenient for disassembly and maintenance. As an optional structural, the spin plate  2  may include an upper spin plate and a lower spin plate. The upper spin plate and the lower spin plate are arranged concentrically, and a passage is formed for spraying out the chemical solution between the upper spin plate and the lower spin plate. At this time, the chemical solution can enter a gap between the upper and lower spin plates and be sprayed from the passage to the surroundings of the spin plate. In order to prevent the chemical solution from being directly thrown out from a peripheral edge of the upper spin plate, the peripheral edge of the upper spin plate may be provided with a water blocking ring. 
     Optionally, the upper spin plate  21  and the lower spin plate  22  are provided with a water guiding groove. As such, the water guiding groove can guide the chemical solution in the gap between the upper spin plate  21  and the lower spin plate  22 , so that the chemical solution can be sprayed out along the path of the water guiding groove, to improve the coverage uniformity of the spraying apparatus when spraying the chemical solution. 
     Specifically, in order to spray the chemical solution to the surroundings of the spin plate  2 , the water guiding groove may be an arc-shaped groove arranged radially from the center of the spin plate  2  to the outer edge of the spin plate  2 . When the spin plate  2  rotates, the chemical solution can be sprayed around the spin plate  2  centrifugally along the arc-shaped water guiding groove, so that there can be a high distribution and coverage range with the chemical solution. 
     In order to further optimize the spraying process of the chemical solution, the arc of the water guiding groove can usually be an Archimedes spiral. Accordingly, when the spin plate  2  rotates at a constant speed, the chemical solution can be evenly sprayed out with the rotation of the spin plate  2  and the coverage can be relatively uniform. 
     In this embodiment, the spraying apparatus includes a driving mechanism having a driving shaft rotatable around its own axis and a spin plate disposed at the bottom of the driving shaft. The spin plate is configured to rotate with the rotation of the driving shaft and spray the chemical solution. The driving mechanism includes a stator assembly, a rotor assembly and a housing assembly. The housing assembly includes a first housing member and a second housing member. The first housing member and the stator assembly are connected. The rotor assembly is connected to the second housing member, and the first housing member is connected to the second housing by snap-fit. The bottom side of the second housing component is provided with a water inlet pipe that is connected to the internal of the spin plate. Accordingly, the spraying apparatus can be easily disassembled, its structure is simple, and the isolation from the chemical solution is good. 
     Based on the foregoing first embodiment, the present disclosure also provides an unmanned aerial vehicle. The unmanned aerial vehicle provided in this embodiment may specifically include a body and the spraying apparatus described in the foregoing first embodiment. The structure, operation principle and effect of the spraying apparatus have been described in detail in the foregoing first embodiment, and will not be repeated here. 
     Specifically, the body of the unmanned aerial vehicle may include a main body, an arm, etc. The spraying apparatus is usually disposed under the main body, and the number of the spraying apparatus may be one or more to meet different spraying needs. 
     In this embodiment, the unmanned aerial vehicle may include a body and a spraying apparatus. The spraying apparatus may include a driving mechanism having a driving shaft rotatable around its own axis and a spin plate disposed at the bottom of the driving shaft. The driving mechanism includes a stator assembly, a rotor assembly and a housing assembly. The housing assembly includes a first housing member and a second housing member. The first housing member is connected to the stator assembly. The rotor assembly is connected to the second housing member, and the first housing member and the second housing member are connected by snap-fit. The bottom side of the second housing member is provided with a water inlet pipe that is connected to the internal of the spin plate. Accordingly, the spraying apparatus can be easily disassembled, its structure is simple, and the isolation from the chemical solution is good. 
     Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than limiting it. Although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skills in the art should understand that the technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently substituted. Such modifications or substitutions do not cause the corresponding technical solutions to deviate from the essence of the technical range of the embodiments of the disclosure.