Patent Publication Number: US-2022227490-A1

Title: Vertical takeoff and landing aerial vehicle and cooling system

Description:
TECHNICAL FIELD 
     The utility model relates to the technology of unmanned aerial vehicles, in particular to a vertical takeoff and landing (VTOL) unmanned aerial vehicle and a cooling system for the unmanned aerial vehicle. 
     BACKGROUND 
     Heat productivity is large during the working period of a lift motor and an electronic speed controller of an existing vertical takeoff and landing unmanned aerial vehicle, but an arm structure of the existing unmanned aerial vehicle is mostly a closed cavity structure which is not conducive to diffusion of hot air. There is generally no heat dissipation for equipment in the arm during the working period of the lift motor and the electronic speed controller of the existing vertical takeoff and landing unmanned aerial vehicle, which causes a certain influence on the equipment in the arm. There is no special equipment for the heat dissipation of the equipment in the arm during the working period of the lift motor and the electronic speed controller of the existing vertical takeoff and landing unmanned aerial vehicle. 
     SUMMARY 
     The utility model relates to a vertical takeoff and landing unmanned aerial vehicle and a cooling system for the unmanned aerial vehicle, which are used for solving the problem that an arm of the unmanned aerial vehicle is poor in heat dissipation. 
     The utility model provides a vertical takeoff and landing unmanned aerial vehicle, which comprises: 
     a left main wing and a right main wing; 
     a left front wing and a right front wing; 
     a main body which is engaged with the left main wing and the right main wing; 
     a left linear support for connecting the left main wing with the left front wing; 
     a right linear support for connecting the right main wing with the right front wing; 
     the left linear support having a first group of multiple lift propellers arranged thereon; 
     the right linear support having a second group of multiple lift propellers arranged thereon; 
     wherein the left linear support and the right linear support each have a hollow interior; and 
     a forward-facing opening which is provided at the front end of each of the left linear support and the right linear support. 
     In one embodiment of the utility model, the radial sectional area of one end, facing the hollow interior, of the opening is less than the radial sectional area of one end, away from the hollow interior, of the opening. 
     In one embodiment of the utility model, the unmanned aerial vehicle further comprises a fan which is arranged in the hollow interior of each of the left linear support and the right linear support. 
     In one embodiment of the utility model, the fan is arranged close to the forward-facing opening to promote air circulation in the hollow interior. 
     In one embodiment of the utility model, the fan is a ducted fan. 
     In one embodiment of the utility model, the unmanned aerial vehicle further comprises motors of the first group of multiple lift propellers and the second group of multiple lift propellers, wherein the motors are arranged in the hollow interiors. 
     In one embodiment of the utility model, the unmanned aerial vehicle further comprises an exhaust port provided at a position close to the tail end of each of the left linear support and the right linear support, thereby allowing air to flow from the hollow interior to an external environment. 
     In one embodiment of the utility model, a plurality of exhaust ports are provided at the left linear support and the right linear support respectively, each exhaust port is in a shape of oblong, the plurality of exhaust ports on the left linear support are arranged around the axis of the left linear support in a spaced manner, and the plurality of exhaust ports on the right linear support are arranged around the axis of the right linear support in a spaced manner. 
     In one embodiment of the utility model, the front end of each of the left linear support and the right linear support is of a circular truncated cone structure, and the opening is provided at the upper bottom face of the circular truncated cone structure; the tail end of each of the left linear support and the right linear support is of a conical structure, and the length directions of the exhaust ports are provided along a generatrix of the conical structure in a spaced manner. 
     In one embodiment of the utility model, the unmanned aerial vehicle further comprises a detachable pod attached to the bottom face of the unmanned aerial vehicle. 
     In one embodiment of the utility model, the pod is a passenger pod or a cargo pod. 
     In one embodiment of the utility model, a rotating shaft of the fan is perpendicular to a rotating shaft of each lift propellers of the plurality of lift propellers. 
     In one embodiment of the utility model, the unmanned aerial vehicle further comprises at least one propulsion propeller arranged on the unmanned aerial vehicle. 
     In one embodiment of the utility model, a diameter of the forward-facing opening is greater than a radius of each of the left linear support and the right linear support. 
     The utility model further provides a cooling system for an unmanned aerial vehicle, which comprises: 
     an opening which is provided on a shell of a linear support; 
     a plurality of lift propellers which are arranged on the linear support; 
     a plurality of motors which are configured to be used for each lift propeller of the plurality of lift propellers in the linear support; 
     and a fan which is arranged in the linear support to supply air from an external environment to an interior of the linear support. 
     In one embodiment of the utility model, the fan is arranged at a position close to the front end of the linear support. 
     In one embodiment of the utility model, the linear support is in a straight configuration. 
     In one embodiment of the utility model, the cooling system further comprises at least one exhaust port which is further provided on the linear support to allow the air to escape from the interior of the linear support. 
     In one embodiment of the utility model, the cooling system further comprises a pod, which is detachably attached to the bottom face of the unmanned aerial vehicle. 
     In one embodiment of the utility model, the pod is a passenger pod or a cargo pod. 
     The utility model provides a vertical takeoff and landing unmanned aerial vehicle, which comprises: a left main wing and a right main wing; a left front wing and a right front wing; a main body which is engaged with the left main wing and the right main wing; a left linear support for connecting the left main wing with the left front wing; a right linear support for connecting the right main wing with the right front wing, the left linear support having a first group of multiple lift propellers arranged thereon, the right linear support having a second group of multiple lift propellers arranged thereon; wherein the left linear support and the right linear support each have a hollow interior; and a forward-facing opening which is provided at the front end of each of the left linear support and the right linear support. According to the vertical takeoff and landing unmanned aerial vehicle provided by the utility model, by providing a forward-facing opening at the front end of each of the left linear support and the right linear support, the air may enter the interior of the left linear support from the opening at the front end of the left linear support and flows out from connection gaps between the left linear support and other components and parts in the forward flight process of the unmanned aerial vehicle, and may enter the interior of the right linear support from the opening at the front end of the right linear support and flows out from connection gaps between the right linear support and other components and parts in the forward flight process of the unmanned aerial vehicle, the heat in the interiors of the left linear support and the right linear support is taken away through the flowing of the air, and the heat dissipation in the arm, i.e., the linear support, of the unmanned aerial vehicle is realized, thereby achieving the purposes of lowering temperature in the arm and protecting equipment in the arm. 
     Although this specification includes many specific implementation details, these should not be construed as limitations on the scope of any utility model or of what may be claimed, but rather as descriptions specific to features of particular implementations of particular embodiments. Certain features that are described in the context of different implementations in this specification may also be implemented in combination in a separate implementation. In contrast, various features described in the context of the separate implementation may also be implemented in multiple implementations separately or in any appropriate sub-combination. In addition, although the features may be described above and below as acting in certain combinations and even initially described as such, one or more features from a described/claimed combination may be excised from the combination in certain cases, and the described/claimed combination may be directed to a sub-combination or variations of the sub-combination. 
     Many implementations have been described. However, it should be understood that various modifications may be made without departing from the spirit and scope of the utility model. For example, the example operations, methods, or processes described herein may comprise more steps or less steps than those described. In addition, the steps in these example operations, methods, or processes may be performed in different alternative ways than those described or illustrated in the figures. 
     The details of one or more implementations of a subject matter described in the utility model are set forth in the accompanying drawings and the description below. Other features, aspects and advantages of the subject matter will become apparent in accordance with the specification, the accompanying drawings, and the technical solutions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It should be noted that the accompanying drawings may be in simplified form and may not be precise in scale. With reference to the disclosure herein, for purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, down, upper side, above, beneath, below, rear portion, front portion, distal end, and proximal end are used with reference to the accompanying drawings. These directional terms should not be construed to limit the scope of the embodiments in any way. 
         FIG. 1 a    is a top perspective view of an embodiment of a VTOL (vertical takeoff and landing) unmanned aircraft system in accordance with one aspect of an embodiment; 
         FIG. 1 b    is a top perspective view of an embodiment of a VTOL unmanned aircraft system in accordance with still another aspect of an embodiment; 
         FIG. 1 c    is a top perspective view of an embodiment of a VTOL unmanned aircraft system in accordance with still another aspect of an embodiment; 
         FIG. 1 d    is a side view illustrating a forward-facing opening of an unmanned aircraft system in accordance with one aspect of an embodiment; 
         FIG. 1 e    is a sectional view of a side portion of an unmanned aircraft system in accordance with one aspect of an embodiment; 
         FIG. 1 f    is a sectional view of a side portion of an unmanned aircraft system in accordance with still another aspect of an embodiment; 
         FIG. 1 g    is a top perspective view of an embodiment of a VTOL unmanned aircraft system in accordance with one aspect of an embodiment; 
         FIG. 2  is a top rear perspective view of the unmanned aircraft system of  FIG. 1   g;    
         FIG. 3  is a side view of the unmanned aircraft system of  FIG. 1   g;    
         FIG. 4  is a top perspective view of another embodiment of a VTOL unmanned aircraft system with a flight platform and a detachably attached pod in accordance with one aspect of the embodiment; 
         FIG. 5  is a top view of the unmanned aircraft system of  FIG. 4  in accordance with one aspect of the embodiment; 
         FIG. 6  is a front view of the unmanned aircraft system of  FIG. 4  in accordance with one aspect of the embodiment; 
         FIG. 7  is a top perspective view of an embodiment of a VTOL unmanned aircraft system with a flight platform and a detachably attached passenger pod in accordance with one aspect of the embodiment; 
         FIG. 8  is a front view of the unmanned aircraft system of  FIG. 7  in accordance with one aspect of the embodiment; 
         FIG. 9  is a rear perspective view of the unmanned aircraft system of  FIG. 7  in accordance with one aspect of the embodiment; 
         FIG. 10  is a side perspective view of the unmanned aircraft system of  FIG. 7  in accordance with one aspect of the embodiment, wherein the passenger pod is detached from the flight platform and parked on the ground; 
         FIG. 11  is a rear perspective view of the embodiment of  FIG. 7  in accordance with one aspect of the embodiment; 
         FIG. 12  is a rear perspective view of another embodiment in accordance with one aspect of the embodiment; 
         FIG. 13  is a side bottom perspective view of still another embodiment of an unmanned aircraft system in accordance with one aspect of the embodiment; 
         FIG. 14  is a perspective view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment; 
         FIG. 15  is a close-up view of an encircled region in  FIG. 14  in accordance with another aspect of the embodiment; 
         FIG. 16  is a side view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment; 
         FIG. 17  is a front view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment; 
         FIG. 18  is a rear view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment; 
         FIG. 19  is an upward view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment; 
         FIG. 20  is a perspective view of another embodiment of a flight platform in accordance with another aspect of the embodiment; 
         FIG. 21  is a side view of another embodiment of a flight platform in accordance with another aspect of the embodiment; 
         FIG. 22  is a front view of another embodiment of a flight platform in accordance with another aspect of the embodiment; 
         FIG. 23  is a rear view of another embodiment of a flight platform in accordance with another aspect of the embodiment; 
         FIG. 24  is an upward view of another embodiment of a flight platform in accordance with another aspect of the embodiment; 
         FIG. 25  is a side view of another embodiment of a passenger pod in accordance with another aspect of the embodiment; 
         FIG. 26  is a bottom perspective view of another embodiment of a passenger pod in accordance with another aspect of the embodiment; 
         FIG. 27  is a front view of another embodiment of a passenger pod in accordance with another aspect of the embodiment; 
         FIG. 28  is a rear view of another embodiment of a passenger pod in accordance with another aspect of the embodiment; 
         FIG. 29  is an upward view of another embodiment of a passenger pod in accordance with another aspect of the embodiment; 
         FIG. 30  is a side view of another embodiment of a flight platform attached to a cargo pod in accordance with another aspect of the embodiment; 
         FIG. 31  is a perspective view of another embodiment of a flight platform without a propulsion propeller in accordance with another aspect of the embodiment; 
         FIG. 32  is a side view of another embodiment of a passenger pod with a propulsion propeller in accordance with another aspect of the embodiment; 
         FIG. 33  is a perspective view of still another embodiment of a flight unmanned aircraft system, wherein six flotation devices are inflated; 
         FIG. 34  is a side view of the unmanned aerial vehicle of  FIG. 33 ; 
         FIG. 35  is a side sectional view of an unmanned aerial vehicle with a cooling system in accordance with an embodiment of the utility model; 
         FIG. 36  is a view illustrating a configuration of an aileron of an unmanned aerial vehicle. 
     
    
    
     Where reference is made to components with reference numerals, like parts are denoted by the same reference numerals throughout the accompanying drawings of the specification: 
       100 —unmanned aerial vehicle;  101 —flight platform;  102 —main body;  103 A—left linear support;  103 B—right linear support;  104 A—left main wing;  104 B—right main wing;  105 A—left front wing;  105 B—right front wing;  106 A—left vertical stabilizer;  106 B—right vertical stabilizer;  107 —propulsion propeller;  107 A—left propulsion propeller;  107 B—right propulsion propeller;  108 A—first lift propeller;  108 B—second lift propeller;  108 C—third lift propeller;  108 D—fourth lift propeller;  108 E—fifth lift propeller;  108 F—sixth lift propeller;  109 A—left wingtip propeller;  109 B—right wingtip propeller;  110 A—left wingtip vertical stabilizer;  110 B—right wingtip vertical stabilizer;  111 A—left folding leg;  111 B—right folding leg;  112 A—first leaf spring;  112 B—second leaf spring;  112 C—third leaf spring;  112 D—fourth leaf spring;  116 —vertical expander;  117 —central propulsion propeller;  130 —cargo pod;  135 A—first pod leaf spring;  135 B—second pod leaf spring;  135 C—third pod leaf spring;  135 D—fourth pod leaf spring;  140 —passenger pod;  145 A—pod leg;  145 B—pod leg;  145 C—pod leg;  145 D—pod leg;  147 —pod-attaching latch;  148 —electric wheel;  149 —shell;  150 —energy storage unit in flight platform;  155 —energy storage unit in pod;  160 —flotation device;  170 —fan;  180 —motor;  190 —opening;  200 —electronic speed controller;  201 —exhaust port;  202 —aileron; A—airflow direction; B—air inlet direction; C—air outlet direction. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Different aspects of various embodiments may now be better understood by turning to the following detailed description of the embodiments, which are presented as illustrative examples of the embodiments defined in the technical solutions. It is expressly understood that the embodiments defined by the technical solutions may be broader than the illustrated embodiments described below. 
     The words used in the specification to describe the various embodiments should be understood to not only have commonly defined meanings thereof, but, in structures, materials, or actions in the specification, to include special definitions beyond the scope of the generally defined meanings. Hence, if a component may be understood in the context of the specification to include more than one meaning, its use in the technical solution must be understood to be general for all possible meanings supported by the specification and the words themselves. 
     The term “unmanned aerial vehicle” is defined as a flight transportation system with at least one propeller as one propulsion source. The term “unmanned aerial vehicle” may comprise both “manned” and “unmanned” flight transportation systems. The “manned” unmanned aerial vehicle may refer to a flight transportation system that carries human passengers, none of which has right of control over the unmanned aerial vehicle. The “manned” unmanned aerial vehicle may also refer to a flight transportation system that carries human passengers, with some or one of the human passengers having a certain right of control over the unmanned aerial vehicle. 
     As the background, during the working period of a lift motor and an electronic speed controller of an existing vertical takeoff and landing unmanned aerial vehicle, there is no special equipment for heat dissipation of equipment in an arm, thus causing a certain influence on the equipment in the arm. To solve the problem that an arm of an unmanned aerial vehicle is poor in heat dissipation, the utility model provides a vertical takeoff and landing unmanned aerial vehicle, which comprises: a left main wing and a right main wing; a left front wing and a right front wing; a main body which is engaged with the left main wing and the right main wing; a left linear support for connecting the left main wing with the left front wing; a right linear support for connecting the right main wing with the right front wing; the left linear support having a first group of multiple lift propellers arranged thereon; the right linear support having a second group of multiple lift propellers arranged thereon, wherein the left linear support and the right linear support each have a hollow interior; and a forward-facing opening which is provided at the front end of each of the left linear support and the right linear support. 
     The technical solutions of the utility model will be described below in detail in conjunction with specific accompanying drawings. 
       FIG. 1 a    is a top perspective view of an embodiment of a VTOL (vertical takeoff and landing) unmanned aircraft system in accordance with one aspect of an embodiment;  FIG. 1 b    is a top perspective view of an embodiment of a VTOL unmanned aircraft system in accordance with still another aspect of an embodiment;  FIG. 1 c    is a top perspective view of an embodiment of a VTOL unmanned aircraft system in accordance with still another aspect of an embodiment;  FIG. 1 d    is a side view illustrating a forward-facing opening of an unmanned aircraft system in accordance with one aspect of an embodiment;  FIG. 1 e    is a sectional view of a side portion of an unmanned aircraft system in accordance with one aspect of an embodiment;  FIG. 1 f    is a sectional view of a side portion of an unmanned aircraft system in accordance with still another aspect of an embodiment;  FIG. 1 g    is a top perspective view of an embodiment of a VTOL unmanned aircraft system in accordance with one aspect of an embodiment;  FIG. 2  is a top rear perspective view of the unmanned aircraft system of  FIG. 1 g   ;  FIG. 3  is a side view of the unmanned aircraft system of  FIG. 1 g   ;  FIG. 4  is a top perspective view of another embodiment of a VTOL unmanned aircraft system with a flight platform and a detachably attached pod in accordance with one aspect of the embodiment;  FIG. 5  is a top view of the unmanned aircraft system of  FIG. 4  in accordance with one aspect of the embodiment;  FIG. 6  is a front view of the unmanned aircraft system of  FIG. 4  in accordance with one aspect of the embodiment;  FIG. 7  is a top perspective view of an embodiment of a VTOL unmanned aircraft system with a flight platform and a detachably attached passenger pod in accordance with one aspect of the embodiment;  FIG. 8  is a front view of the unmanned aircraft system of  FIG. 7  in accordance with one aspect of the embodiment;  FIG. 9  is a rear perspective view of the unmanned aircraft system of  FIG. 7  in accordance with one aspect of the embodiment;  FIG. 10  is a side perspective view of the unmanned aircraft system of  FIG. 7  in accordance with one aspect of the embodiment, wherein the passenger pod is detached from the flight platform and parked on the ground;  FIG. 11  is a rear perspective view of the embodiment of  FIG. 7  in accordance with one aspect of the embodiment;  FIG. 12  is a rear perspective view of another embodiment in accordance with one aspect of the embodiment;  FIG. 13  is a side bottom perspective view of still another embodiment of an unmanned aircraft system in accordance with one aspect of the embodiment;  FIG. 14  is a perspective view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment;  FIG. 15  is a close-up view of an encircled region in  FIG. 14  in accordance with another aspect of the embodiment;  FIG. 16  is a side view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment;  FIG. 17  is a front view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment;  FIG. 18  is a rear view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment;  FIG. 19  is an upward view of one embodiment of an unmanned aircraft system in accordance with another aspect of the embodiment;  FIG. 20  is a perspective view of another embodiment of a flight platform in accordance with another aspect of the embodiment;  FIG. 21  is a side view of another embodiment of a flight platform in accordance with another aspect of the embodiment;  FIG. 22  is a front view of another embodiment of a flight platform in accordance with another aspect of the embodiment;  FIG. 23  is a rear view of another embodiment of a flight platform in accordance with another aspect of the embodiment;  FIG. 24  is an upward view of another embodiment of a flight platform in accordance with another aspect of the embodiment;  FIG. 25  is a side view of another embodiment of a passenger pod in accordance with another aspect of the embodiment;  FIG. 26  is a bottom perspective view of another embodiment of a passenger pod in accordance with another aspect of the embodiment;  FIG. 27  is a front view of another embodiment of a passenger pod in accordance with another aspect of the embodiment;  FIG. 28  is a rear view of another embodiment of a passenger pod in accordance with another aspect of the embodiment;  FIG. 29  is an upward view of another embodiment of a passenger pod in accordance with another aspect of the embodiment;  FIG. 30  is a side view of another embodiment of a flight platform attached to a cargo pod in accordance with another aspect of the embodiment;  FIG. 31  is a perspective view of another embodiment of a flight platform without a propulsion propeller in accordance with another aspect of the embodiment;  FIG. 32  is a side view of another embodiment of a passenger pod with a propulsion propeller in accordance with another aspect of the embodiment;  FIG. 33  is a perspective view of still another embodiment of a flight unmanned aircraft system, wherein six flotation devices are inflated;  FIG. 34  is a side view of the flight unmanned aerial vehicle of  FIG. 33 ;  FIG. 35  is a side sectional view of an unmanned aerial vehicle with a cooling system in accordance with an embodiment of the utility model;  FIG. 36  is a view illustrating a configuration of an aileron of an unmanned aerial vehicle. 
       FIG. 1 a    is a top perspective view of an embodiment of a VTOL unmanned aircraft system in accordance with one aspect of an embodiment. The unmanned aerial vehicle  100  at least comprises: a left main wing  104 A and a right main wing  104 B; a left front wing  105 A and a right front wing  105 B; a main body  102  which is engaged with the left main wing  104 A and the right main wing  104 B; a left linear support  103 A for connecting the left main wing  104 A with the left front wing  105 A; a right linear support  103 B for connecting the right main wing  104 B with the right front wing  105 B, the left linear support  103 A having a first group of multiple lift propellers  108 A,  108 B,  108 C arranged thereon; the right linear support  103 B having a second group of multiple lift propellers  108 D,  108 E,  108 F arranged thereon; wherein the left linear support  103 A and the right linear support  103 B each have a hollow interior; and a forward-facing opening  190  which is provided at the front end of each of the left linear support  103 A and the right linear support  103 B. 
     By adopting a vertical takeoff and landing unmanned aerial vehicle provided by the utility model, heat dissipation in an arm of the unmanned aerial vehicle is realized by providing a forward-facing opening at the front end of each of a left linear support and a right linear support, thereby achieving the purposes of lowering the temperature in the arm and protecting equipment in the arm. 
     Preferably, as shown in  FIG. 1 e    and  FIG. 1 f   , the radial sectional area of the right end of the opening  190 , i.e., one end toward the hollow interior, is less than the radial sectional area of the left end of the opening  190 , i.e., one end away from the hollow interior, that is, the opening  190  is formed as a trumpet-shaped structure. It may be understood by those skilled in the art that the sectional area gradually decreases as air passes through the opening  190  to enter the hollow interior, the volume of the air is compressed as it passes through the opening  190 , and a flow rate increases to increase the flow rate of the air in the hollow interior, thus increasing the cooling efficiency of the linear support. 
       FIG. 1 g    depicts an embodiment of a VTOL unmanned aerial vehicle  100  with a front wing configuration in general. 
     The various part features of the unmanned aerial vehicle  100  in the various embodiments shown in the accompanying drawings, which are illustrative only, may be flexibly combined to form an unmanned aerial vehicle with a new structure. 
     The unmanned aerial vehicle  100  in  FIG. 3  may have two main wings  104 A,  104 B as a left main wing and a right main wing, and two front wings as a left front wing  105 A and a right front wing  105 B. The two main wings  104 A,  104 B and the two front wings  105 A,  105 B may be attached to a main body  102 , wherein the main body may be positioned along a central longitudinal line of the unmanned aerial vehicle  100 . The unmanned aerial vehicle  100  may also have a left linear support  103 A arranged parallel to the main body  102 , which may connect the left main wing  104 A to the left front wing  105 A. Similarly, the unmanned aerial vehicle  100  may also have a right linear support  103 B arranged parallel to the main body  102 , which may connect the right main wing  104 B to the right front wing  105 B. Wherein, the front wings of the unmanned aerial vehicle mainly control a flight attitude of an unmanned aerial vehicle during the flight period, such as controlling the pitch of the unmanned aerial vehicle. The main wings of the unmanned aerial vehicle, acting as the largest wings at two sides of a fuselage, are usually used for generating lift to support the unmanned aerial vehicle to fly in the air, and meanwhile, certain stabilization and manipulation effects are achieved. 
     In still another embodiment, the unmanned aerial vehicle  100  may also not have the front wing configuration. Illustratively, the unmanned aerial vehicle  100  may have two main wings as a left main wing and a right main wing, and two ailerons as a left aileron and a right aileron, all of which are engaged together to form a flight platform. 
     In one embodiment, as shown in  FIG. 36 , the aileron  201  of the unmanned aerial vehicle may be arranged at a rear side of the main wing  104 B, there may be at least one aileron, preferably two, which is in a sheet-like configuration, and capable of moving up and down to control the roll of the unmanned aerial vehicle. 
     The left linear support  103 A and the right linear support  103 B are expected to improve the structural integrity of the unmanned aerial vehicle  100 . In other embodiments, the left linear support  103 A and the right linear support  103 B may accommodate a driving motor (not shown) for driving each of lift propellers  108 A,  108 B,  108 C,  108 D,  108 E,  108 F. Thus, the left linear support  103 A and the right linear support  103 B may be used for fixing the lift propellers to reduce usage of the parts of the unmanned aerial vehicle, and while simplifying structural parts of the unmanned aerial vehicle, the overall strength of the unmanned aerial vehicle may be improved due to the engagement of the left linear support  103 A and the right linear support  103 B with the two front wings and the two main wings. As will be disclosed later, the left linear support  103 A and the right linear support  103 B may also accommodate folding legs  111 , each of which may be retracted into the left linear support  103  A and the right linear support  103 B. 
     In one embodiment, the left linear support  103 A and the right linear support  103 B are attached to the distal ends of the left front wing  105 A and the right front wing  105 B respectively. In still another embodiment, the left linear support  103 A and the right linear support  103 B extend beyond the front wings  105 A,  105 B. 
     In one embodiment, the left linear support  103 A and the right linear support  103 B are attached to positions near the middle portions of the left main wing  104 A and the right main wing  104 B respectively. In still another embodiment, the left linear support  103 A and the right linear support  103 B extend beyond the main wings  104 A,  104 B along a backwards direction. 
     The left linear support  103 A is expected to be relative narrow in diameter, and may have a first group of multiple lift propellers  108 A,  108 B,  108 C arranged at the top side, the bottom side, or both, of the left linear support  103 A. In one feasible embodiment, these lift propellers  108 A,  108 B, and  108 C may be driven by low profile motors arranged in the hollow interior of the left linear support  103 A. In an embodiment shown in  FIG. 1 g   , the lift propellers  108 A,  108 B,  108 C are only arranged at the top side of the left linear support  103 A. It should be noted that the number of the lift propeller shown in the figure is for illustrative purpose only, the utility model is not intended to limit the number of the lift propeller, and the lift propeller may be increased or decreased according to the demand in actual. Likewise, the right linear support  103 B is expected to be relative narrow in diameter, and may have a second group of multiple lift propellers  108 D,  108 E,  108 F arranged at the top side, the bottom side, or both, of the right linear support  103 B. In one feasible embodiment, these lift propellers  108 D,  108 E,  108 F may be driven by low profile motors arranged in a hollow interior of the right linear support. In an embodiment shown in  FIG. 1 g   , the lift propellers  108 D,  108 E,  108 F are only arranged at the top side of the right linear support  103 B. It should be noted that the number of the lift propeller shown in the figure is for illustrative purpose only, the utility model is not intended to limit the number of the lift propeller, and the lift propeller may be increased or decreased according to the demand in actual. 
     In one embodiment, the left linear support  103 A has at least one forward-facing opening provided thereon. Illustratively, referring to  FIG. 1 b   , at least one forward-facing opening  190  may be provided at the front end of the left linear support  103 A, thereby allowing air to enter the hollow interior of the left linear support  103 A from an external environment. It should be noted that the forward-forcing opening shown in  FIG. 1 b    is for illustrative purpose only, the utility model is not intended to limit the shape and number of the forward-forcing opening, and the forward-forcing opening may be flexibly provided according to the demand in actual. In one embodiment, the right linear support  103 B has a forward-facing opening (not shown) provided thereon, but may be similarly provided as shown in  FIG. 1 b   , thereby allowing the air to enter the hollow interior of the right linear support  103 B from the external environment; the forward-facing opening may be flexibly provided, for example, the forward-facing opening may likewise be provided at the front end of the right linear support  103 B. 
     By providing the forward-facing openings, when the unmanned aerial vehicle starts to fly, the air enters from the openings  190  at the front ends of arms (i.e., the left linear support and the right linear support) and flows out from the connection gaps between the arms and other components and parts, such as motors, to form backward-flowing airflow in the arms, thereby accelerating heat dissipation. 
     As shown in  FIG. 1 e    and  FIG. 1 f   , one possible implementation is that the front end of each of the left linear support  103 A and the right linear support  103 B is of a circular truncated cone structure, and the opening  190  is provided on the upper bottom face of the circular truncated cone structure, preferably, the size of the opening  190  is same as that of the circular truncated cone structure. It may be understood by those skilled in the art that the front end of the linear support is formed as a circular truncated cone structure which may reduce resistance of the air to the linear support in the flight process of the unmanned aerial vehicle  100 , and thus the cruising ability of the unmanned aerial vehicle  100  is improved. 
     In one embodiment, the unmanned aerial vehicle  170  further comprises a fan  170  which is arranged in the hollow interior of each of the left linear support  103 A and the right linear support  103 B. The fan may accelerate air flow to make the heat in the arm to be taken away as quick as possible, thereby lowering the heat in the arm. 
     In one embodiment, the fan is arranged close to the forward-facing opening  190 , and forcibly promotes air circulation in the hollow interior, please referring to the illustrative arrangement of the fan  170  in  FIG. 1 e    and  FIG. 1   f.    
     By installing a cooling fan in each of the left linear support  103 A and the right linear support  103 B of the unmanned aerial vehicle respectively, the cooling fan starts to work during the working period of a lift motor of the unmanned aerial vehicle, and hot airflow in the arm is exhausted through a flow field generated by the cooling fan, thereby achieving the purposes of lowering the temperature in the arm and protecting equipment in the arm. 
     Illustratively, one cooling fan is arranged below and in front of the lift motor, a wind field of the cooling fan blows towards the rear portion of the arm to form a backward-flowing airflow in the arm, and when the vertical takeoff and landing unmanned aerial vehicle is shifted to a level flight stage, the lift motor stops working, and the cooling fan stops working at the same time. 
     The utility model is not intended to limit a specific structure of the fan  170 , illustratively, a ducted fan  170  may by adopted, an outer wall of the ducted fan  170  is fixedly connected to an inner wall of the linear support, and the ducted fan  170  is close to the front end of the linear support. It may be understood by those skilled in the art that, with a certain installation space for the fan  170 , the ducted fan  170  generates a greater thrust force on the air compared to the ordinary fan  170 , and the air flows at a greater speed in the hollow interior, and thus the cooling rate to the linear support is higher. 
     In one embodiment, the unmanned aerial vehicle further comprises motors  180  of the first group of multiple lift propellers  108 A,  108 B,  108 C and the second group of multiple lift propellers  108 D,  108 E,  108 F, the motors are arranged in the hollow interiors and used for driving the corresponding lift propellers, thereby achieving vertical takeoff and landing functions of the unmanned aerial vehicle. 
     In one embodiment, the unmanned aerial vehicle further comprises an exhaust port  201  provided at a position close to the tail end of each of the left linear support  103 A and the right linear support  103 B, thereby allowing the air to flow to the external environment from the hollow interior. 
     One possible implementation is that a plurality of exhaust ports  201  are provided at the left linear support  103 A and the right linear support  103 B respectively, the plurality of exhaust ports  201  on the left linear support  103 A are arranged around the axis of the left linear support  103 A in a spaced manner, and the plurality of exhaust ports  201  on the right linear support  103 B are arranged around the axis of the right linear support  103 B in a spaced manner. Illustratively, the exhaust port  201  may be in a shape of oblong. It may be understood by those skilled in the art that the shape of the exhaust port  201  is provided to be oblong, and on the premise of guaranteeing that the air in the hollow interior may smoothly flow out from the exhaust port  201 , the influence on the structural strength of the linear support due to excessive size of the exhaust port  201  is avoided. 
     Preferably, the tail ends of the left linear support  103 A and the right linear support  103 B are formed as a conical structure. It is easy to understand that the tail ends of the left linear support  103 A and the right linear support  103 B are formed as a tapered structure, and in the flight process of the unmanned aerial vehicle  100 , the conical structures at the tail ends of the left linear support  103 A and the right linear support  103 B may play a role in rectification, and thus the air resistance of the air to the left linear support  103 A and the right linear support  103 B is reduced. Illustratively, length directions of the exhaust ports  201  are arranged along a generatrix of the left linear support  103 A and a generatrix of the right linear support  103 B in a spaced manner. 
     In one embodiment, the unmanned aerial vehicle further comprises a detachable pod attached to the bottom face of the unmanned aerial vehicle, and the pod is a passenger pod or a cargo pod. By means of the arrangement mode as above, a structure of the unmanned aerial vehicle may be flexibly adjusted; in accordance with the actual conditions, the pod may be installed when needed, and may be detached when not needed, and therefore the unmanned aerial vehicle may be flexibly used in response to different requirements, and the adaptability of the unmanned aerial vehicle is improved. 
     In one embodiment, the main wing and the aileron are configured as a front wing configuration. As shown in  FIG. 36  and the rest accompanying drawings showing the front wing configuration, the main wing and aileron may be a plate-like configuration of the main wing. 
     In one embodiment, a rotating shaft of the fan  170  is perpendicular to a rotating shaft of each lift propeller of the plurality of lift propellers  108 A,  108 B,  108 C,  108 D,  108 E,  108 F. Such arrangement makes cooling fan blades of the fan be perpendicular to propeller blades of the unmanned aerial vehicle, as shown in  FIG. 1 e    and  FIG. 1 f   , airflow A generated by rotation of the fan horizontally flows backwards in the linear support; the situation that, due to the fact that the fan is not arranged in such a way, the airflow A in the hollow interior is influenced by the inner surface of the arm and cannot flow through the hollow interior as quickly as possible to take away the heat is avoided. 
     In one embodiment, a diameter of the forward-facing opening  190  is greater than a radius of each of the left linear support  103 A and the right linear support  103 B. Such providing of the size of the forward-facing opening may make the air enter the interior of the linear support more easily, thereby facilitating the heat dissipation. 
     In one embodiment, the unmanned aerial vehicle  100  may have at least one propulsion propeller  100  to propel the unmanned aerial vehicle  100  in a forward direction. In the embodiments shown in  FIG. 1 b   ,  FIG. 1 c    and  FIG. 1 g   , there may be two propulsion propellers  107 A,  107 B. The two propulsion propellers  107 A,  107 B may be arranged at the distal ends of the rear portions of the linear support  103 A,  103 B. 
     In still another embodiment, such as an embodiment shown in  FIG. 33 , a flight platform  101  may not have a propulsion propeller. In such embodiment, the flight platform  101  may be attached to a passenger pod or a cargo pod which is provided with the propulsion propeller.  FIG. 32  illustrates an embodiment of a passenger pod having a propulsion propeller arranged at the rear end thereof. When the passenger pod is attached to the flight platform  101  of  FIG. 31 , the propulsion propeller propels the flight platform  101  forwards. 
     In one embodiment, two vertical stabilizers  106 A,  106 B may be arranged at positions near the rear ends of the linear supports  103 A,  103 B respectively. Although the vertical stabilizers are shown pointing downward, there may have implementations possible in which the vertical stabilizers point upward. 
     In another embodiment, as shown in  FIG. 1 c    and  FIG. 2 , the main wings  104 A,  104 B may be respectively provided with wingtip lift propellers  109 A,  109 B arranged at the distal ends thereof. This may be achieved by providing the wingtip vertical stabilizers  110 A,  110 B at the distal ends of the main wings  104 A,  104 B, respectively, and having lift propellers  109  A,  109 B arranged at the upper tips of the wingtip vertical stabilizers  110 A,  110 B. These wingtip lift propellers  109 A,  109 B may be relatively smaller than the lift propellers arranged on the linear supports  103 A,  103 B. 
     These wingtip lift propellers  109 A,  109 B may be used for efficiently and effectively controlling the roll of the unmanned aerial vehicle  100 . These wingtip lift propellers  109 A,  109 B are located at the most distal positions away from the center axis of the unmanned aerial vehicle  100  and are effective in regulating the roll of the unmanned aerial vehicle  100 , and may do so with a diameter less than those of the other lift propellers. 
     As further shown in  FIG. 1 g   , there is a pod  130  normally attached beneath the main body  102  of the unmanned aerial vehicle  100 . 
     Now referring to details in  FIG. 2 , the unmanned aerial vehicle  100  is expected to use any type of landing gear. In one embodiment, the unmanned aerial vehicle  100  may have four single leaf springs  112 A,  112 B,  112 C,  112 D as the landing gears. The front two single leaf springs  112 A,  112 C are respectively arranged at the distal ends of folding legs  111 A,  111 B. During the flight, the folding legs  111 A,  111 B may be respectively retracted into interior spaces of the left linear support  103 A and the right linear support  103 B. 
     In one embodiment, the tail end of the landing gear of the unmanned aerial vehicle may be provided with the leaf spring as shown in  FIG. 1 a    to  FIG. 15 , or the tail end of the landing gear of the unmanned aerial vehicle may be provided with an electric wheel as shown in  FIG. 14  to  FIG. 34 . 
     The two single leaf left springs  112 B,  112 D at the rear side are expected to be respectively arranged at the distal ends of the bottom of the vertical stabilizers  106 A,  106 B. 
     The expected single leaf springs  112 A,  112 B,  112 C,  112 D may be made of appropriate materials to provide enough elasticity and integrity, the materials comprise natural and synthetic polymers, various metals and metallic alloy, natural materials, textile fibers, and all reasonable combination thereof. In one embodiment, carbon fibers are used. 
     Now turning to  FIG. 3 , a pod used as a cargo pod  130  is illustrated. The cargo pod  130  may have single leaf springs  135 A,  135 B,  135 C,  135 D as landing gears thereof. Or, the cargo pod  130  may have other type of landing gear, for example, sliding rails, legs, and wheels. 
     In an expected embodiment, the cargo pod  130  may be detached from the other portion of the unmanned aerial vehicle  100 . The other portion of the unmanned aerial vehicle may be called as a flight platform  101 . The flight platform  101  may fly without carrying the pod, and may interchangeably carry different pods. As will be described later, the flight platform  101  may also carry a passenger pod. 
     In an illustrated embodiment, all pods  130 ,  140  are carried beneath the flight platform  101 . The pods  130 ,  140  are expected to be loaded on the ground, and the loading process may be completed before or after attaching the flight platform  101  to the pods  130 ,  140 . 
       FIG. 5  illustrates a top view of a flight platform  101 . The flight platform  101  may have a generally flat configuration, and capable of carrying a load therebelow or thereabove. During high-speed flight, all six lift propellers  108 A,  108 B,  108 C,  108 D,  108 E,  108 F may be locked in place, and thus each blade is parallel to the main body  102 . 
       FIG. 5  illustrates one embodiment of a flight platform  101 , wherein the length of each of the front wings  105 A,  105 B is not longer than a half of the length of each of the main wings  104 A,  104 B. 
       FIG. 6  depicts a front view of a flight platform  101  with a detachably attached cargo pod  130  in general. Whether the cargo pod  130 , the passenger pod  140 , or any other type of load, it is specifically expected that there may be an energy storage unit  150  arranged in the main body  102  of the flight platform. Stored energy may be used to power the other parts of the flight platform, such as lift propellers  108 A,  108 B,  108 C,  108 D, and propulsion propellers  107 A,  107 B. The stored energy may be electric power, and the storage unit is a battery. In another embodiment, the energy storage  150  may be used to power accessories in the pods  130 ,  140 . 
     These batteries  150  may also be arranged in the other portions of the flight platform  101 , such as in the linear supports  103 A,  103 B. 
     Alternatively or preferably, there may be an energy storage unit  155  arranged in each of the pods  130 ,  140 . Energy stored in the storage unit  155  may be used to power the lift propellers  108 A,  108 B,  108 C,  108 D, and the propulsion propellers  107 A,  107 B. The stored energy may be electric power, and the storage unit is a battery. By arranging the energy storage units  155  in the pods  130 ,  140 , whenever the flight platform  101  is attached to a new pod  130  or  140 , the flight platform  101  will have a supplemental energy source. The flight platform  101  itself may be an emergency energy store or a battery  150  with smaller capacity to supply electric power to the flight platform  101  for a relatively short period of time when the flight platform  101  is in flight without the pods  130 ,  140 . In one embodiment, the main power supply of the flight platform  101  is from the batteries  150  located in the pods  130 ,  140 . In this way, the flight platform  101  or the entire VTOL unmanned aircraft system  100  will have a fully charged energy source when the flight platform  101  replaces the old pods  130 ,  140  with the new pods  130 ,  140 . This is a beneficial method without requiring the VTOL unmanned aerial vehicle to charge itself. In a preferred embodiment, the flight platform  101  may work/fly continuously for hours or even days to attach the cargo pod/passenger pod and detach the cargo pod/passenger pod without stopping to charge batteries thereof. 
     Now referring to the details of  FIG. 7 , a passenger pod  150  is provided. The passenger pod  150  may use any type of landing gear, such as rigid legs  145 A,  145 B,  145 C,  145 D as shown in the figure. 
       FIG. 10  depicts one aspect of the utility model in general, wherein a pod (whether a cargo pod or a passenger pod) is detachable. Here, the passenger pod  140  may be selectively detached from the flight platform  101 . The attachment and detachment between the flight platform  101  and the pod  140  may be autonomously executed (without simultaneous user intervention) by a computer and/or other sensors and a calculation device. Alternatively or preferably, a user may actively control and guide the attachment and detachment between the flight platform  101  and the pod  140 . 
     As will be recognized by those of ordinary skill in the art, various types of attachment mechanisms  147  may be used to fix the pod  140  to the flight platform  101 . For example, the attachment mechanism may be a mechanical latch, a magnetic latch, a track and groove, or a combination of any known engagement ways. 
     It is important to understand that, in addition to having two propulsion propellers  107 A and  107 B (as shown in  FIG. 11 ), alternatively or alternatively, there may be a central propulsion propeller  117  which is connected to the rear end of the main body  102  (as shown in  FIG. 12 ). As shown in  FIG. 12 , the central propulsion propeller  117  is engaged to the rear end of the main body  102  through a vertical expander  116 . The vertical expander  116  may be any structure in any shape to physically engage with the propulsion propeller  117 , thereby making a rotating center of the propulsion propeller  117  perpendicularly deviate from the main body  102 . In still another embodiment, the propulsion propeller  117  perpendicularly deviates from the main body  102 , thereby making the rotating center of the propulsion propeller  117  be perpendicularly located at a position at the rear portion of the pod  140  or be perpendicularly flushed with the pod  140 . In another embodiment, the propulsion propeller  117  is perpendicularly flushed with the top of the pod  140 . In another embodiment, the propulsion propeller  117  is perpendicularly flushed with the middle portion of the pod  140 . In a further embodiment, the propulsion propeller  117  is perpendicularly flushed with the bottom of the pod  140 . 
     What is not shown in any figure of the embodiment is the absence of the propulsion propellers  107 A,  107 B at the end parts of the linear supports  103 A,  103 B respectively. Instead, there may only be one propulsion propeller  117  engaged with the rear end of the main body  102 . 
     It may also be contemplated that each of the linear support  103 A,  103 B may comprise more than three lift propellers, which may be achieved by providing a longer linear support to accommodate more lift propellers, by using a lift propeller with smaller diameter, or by placing lift propellers on both the top and bottom sides of the linear support. One embodiment is illustrated in  FIG. 13 , wherein two additional lift propellers  108 G  108 H are arranged at the front ends of the bottoms of the linear supports  103 A,  103 B. 
     Although the propulsion propellers  107 A,  107 B have been illustrated in the foregoing figures to be positioned at the distal ends of the rear portions of the linear support  103 A,  103 B, it is particularly expected that these propulsion propellers  107 A,  107 B may be arranged at a horizontal plane lower than the main wings  104 A,  104 B, as those shown in  FIG. 13 . In one aspect, these propulsion propellers  107 A,  107 B may be arranged at a horizontal plane which is basically equal to the pods  130 ,  140  carried by the flight platform. In another aspect, these propulsion propellers  107 A,  107 B may be arranged at the middles of the vertical stabilizers  106 A,  106 B. One expected reason for lowering the arrangement of the propulsion propellers  107 A,  107 B is to minimize head dipping effect during the flight, which may be caused by aerodynamic effects caused by the pods  130 ,  140 . 
       FIG. 14  to  FIG. 30  illustrate an embodiment in which a flight platform  101  or pods  130 ,  140 , or both, may each have electric wheels  148  attached thereto. In an embodiment of  FIG. 14 , the flight platform  101  is provided with the electric wheels  148 ; and the pods  130 ,  140  are also provided with the electric wheels. Now referring to an embodiment of the  FIG. 15 , single electric wheel  148  unit may have a motor enclosed in a shell  149 , and the motor may be driven the electric power supplied by the energy storage unit  150  arranged in each of the pods  130 ,  140 . 
     It is contemplated that the electric wheels  148  may enable the flight platform  101  or the pod  130  to move on the ground when the flight platform and the pod are parked on the ground. This allows the one of the pods  130 ,  140  to move away from the flight platform  101  and allows the other of the pods  130 ,  140  to move itself to the flight platform  101  for attachment. 
     Or, this may allow the flight platform  101  to be away from the pod  130  and to move towards another pod for attachment. In one embodiment, each of the pods  130 ,  140  may have an energy storage unit  155 , and therefore, an energy source of the flight platform  101  is substantially supplemented when the flight platform  101  is engaged with a new and fully charged pod  130  or  140 . 
     In certain embodiments of the disclosed unmanned aircraft system, at least one flotation device  160  may be provided, which is engaged with at least one of the cargo pod  130 , the passenger pod  140 , and the flight platform  101 . The flotation device may be of the type that requires actuation, that is, active inflation with gas or through material when needed. In other words, in this particular embodiment, the flotation device  160  may remain in a deflated state and can expand only when the inflation is triggered at certain conditions. For example, the flotation device  160  may automatically inflate during emergency landing, may automatically inflate when landing on water, and may inflate when any landing gear fails in certain aspects. 
     Many known types of inflation mechanisms or airbag mechanisms may be implemented to achieve the needs and configuration of the disclosed flotation device  160 . The expected flotation device  160  may be of a type that may be repeatedly reused, re-inflated, and re-deflated. The expected flotation device  160  may be merely disposable. 
     Alternatively or preferably, an inflation behavior may be activated by a user. For example, when an operator of the unmanned aircraft system determines that the flotation device  160  needs to be inflated, he or she may send a signal to start the inflation. 
     It should be particularly noted in certain embodiments that the flotation device  160  does not need the electric wheel  148 . In other embodiments, the flotation device  160  is a portion of a shell of the electric wheel  148 . 
     Referring to  FIG. 26  as one example, a passenger pod  140  may have a lengthened type flotation device  160  arranged on any side of the pod  140 , which may be used as a water landing gear. In  FIG. 26 , these flotation devices  160  are shown deflated.  FIG. 32  illustrates a side view of a deflated flotation device  160 . As shown in  FIG. 33  and  FIG. 34 , the flotation device  160  engaged with the passenger pod  140  is shown inflated. 
     Referring  FIG. 31  as another example, the flight platform  101  may have four flotation devices  160  respectively arranged on the tops of four electric wheels  148 . These flotation devices  160  may be alternatively attached to the electric wheels  148  or close to the electric wheels  148  at the other positions. In  FIG. 31 , these flotation devices  160  engaged with the electric wheels are shown deflated.  FIG. 33  and  FIG. 34  illustrate an inflated flotation device  160  of a flight platform  101 . 
     As above, the forward-facing opening is provided at the front end of the arm of the unmanned aerial vehicle, further preferably, a cooling fan is installed in the arm of the unmanned aerial vehicle, during the working period of a lift motor of the unmanned aerial vehicle, hot airflow in the arm is exhausted through the forward-facing opening or further through a flow field generate by the cooling fan, thereby achieving the purposes of lowering temperature in the arm and protecting equipment in the arm. 
     According to the technical solutions of the utility model, heat dissipation in an arm of an unmanned aerial vehicle is achieved by providing a forward-facing opening at the front end of each of a left linear support and a right linear support of the unmanned aerial vehicle, thereby achieving the purposes of lowering temperature in the arm and protecting equipment in the arm. 
       FIG. 35  is a side sectional view of an unmanned aerial vehicle with a cooling system in accordance with an embodiment of the utility model. Please referring to  FIG. 35 , a cooling system for an unmanned aerial vehicle provided by the utility model comprises an opening (not shown) which is provided on a shell of a hollow linear support  103 A; a plurality of lift propellers  108 A,  108 B, and  108 C which are arranged on the hollow linear support  103 A; a plurality of motors  180  which are configured to be used for the lift propellers  108 A,  108 B, and  108 C in the plurality of lift propellers in the hollow linear support  103 A; and a fan  170  which is arranged in the linear support  103 A to supply air from an external environment to the interior of the hollow linear support. 
     Preferably, the openings may be provided at the front end and the rear end of the shell of the hollow linear support  103 A according to an air inlet direction B and an air outlet direction C in  FIG. 35 . The gas moves along an airflow direction A in the hollow linear support  103 A. 
     In one embodiment, a fan is arranged at a position close to the front end of the linear support, thus airflow A in the linear support may flow through the linear support more quickly to take away all heat in the hollow interior more quickly. 
     In one embodiment, the linear support is in a straight configuration which is in favor of improving the overall strength of the unmanned aerial vehicle. 
     In one embodiment, the cooling system further comprises at least one exhaust port which is provided on the linear support to allow the air to escape from the interior of the linear support. 
     In one embodiment, the cooling system further comprises a pod which is detachably attached to the bottom face of the unmanned aerial vehicle, wherein the pod is a passenger pod or a cargo pod. By means of the arrangement mode as above, a structure of the unmanned aerial vehicle may be flexibly adjusted; in accordance with the actual conditions, the pod may be installed when needed, and may be detached when not needed, and therefore the unmanned aerial vehicle may be flexibly used in response to different requirements, and the adaptability of the unmanned aerial vehicle is improved. 
     The heat dissipation in the arm of the unmanned aerial vehicle may be achieved by adopting the cooling system for the unmanned aerial vehicle provided by the utility model. 
     Many variations and modifications may be made by those of ordinary skill in the art without departing from the spirit and scope of the disclosed embodiments. Thus, it must be understood that the illustrated embodiments are presented for the purpose of example only and should not be taken as limiting the embodiments defined by the appended technical solutions. For example, despite the fact that elements of the technical solutions are presented below in a certain combination, it must be expressly understood that the embodiment comprises other combinations of less, more or different elements, which are disclosed herein, even if such a combination is not initially defined. 
     Therefore, detailed embodiments and applications of a VTOL flight platform with interchangeable pods have been disclosed. However, it is apparent to those skilled in the art that more modifications in addition to those already described are possible without departing from the concepts disclosed herein. Thus, the disclosed embodiments are not limited except in the spirit of the appended technical solutions. In addition, in interpreting the specification and technical solutions, all terms should be interpreted as the broadest possible manner consistent with the context. Particularly, the terms “comprise” and “comprising” should be interpreted as referring to components, assemblies, or steps in a non-exclusive manner, indicating that the referenced components, assemblies, or steps may be present, or utilized, or combined with other components, assemblies, or steps that are not expressly referenced. Insubstantial variations from the claimed subject matter now known or later expected by those of ordinary skill in the art are expressly expected to be equivalent within the scope of the technical solutions. Thus, obvious replacements which are known at present or later to those of ordinary skill in the art are defined to be within the scope of the defined elements. Thus, the technical solutions should be understood to encompass what is specifically illustrated and described above, what is conceptually equivalent, what may be obviously replaced, and what essentially comprise the basic idea of the embodiments. In addition, in the case that the specification and technical solutions refer to at least one selected from a group consisting of A, B, C, . . . and N, the text should be interpreted as requiring at least one element of the group, including N, rather than A plus N, or B plus N, or the like.