Self-cooling motor and hot air circulation device suitable for the same

Abstract

The present invention provides a self-cooling motor and a hot air circulation device applicable thereto. The self-cooling motor includes a housing, a stator assembly, a rotor assembly and an impeller. The housing includes a cylindrical baffle wall and a bottom plate, and the cylindrical baffle wall and the bottom plate define a space. The cylindrical baffle wall has a first end and a second end opposite to each other. The bottom plate is adjacent to the first end, and forms an air inlet radially toward the cylindrical baffle wall. The stator assembly is fixed to the housing and accommodated in the space. The rotor assembly is coupled to the stator assembly, and includes a rotating shaft extending axially to the outside of the housing. The impeller is fixed on the rotating shaft, and is adjacent to the second end, forming an air outlet radially toward the cylindrical baffle wall. When the rotating shaft drives the impeller to rotate, the airflow generated by the impeller enters radially through the air inlet and is discharged through the air outlet.

Description

Technical Field

[0001] The invention relates to a motor, in particular to a self-cooling motor and a hot air circulation device applicable thereto. Background Art

[0002] In the current food heat treatment equipment on the market, the hot air circulation device mostly uses an AC motor, which extends to the heating chamber through the rotating shaft and drives the fan group to rotate, so that the hot air in the heating chamber circulates. However, since the AC motor is not easy to provide forward and reverse rotation and speed control functions, it is easy to cause uneven temperature distribution in the heating chamber, which in turn leads to reduced food heating quality.

[0003] In order to further improve the food heating quality of food heat treatment equipment, brushless DC motors are used to replace AC motors as the driving motors of food heat treatment equipment in the market. Since brushless DC motors have forward and reverse rotation and speed control functions that AC motors do not have, they can replace AC motors to make the circulation of hot air in the heating chamber more uniform, achieving better food heating quality.

[0004] However, when combined with a hot air circulation device, the motor device and the heating chamber need to be connected through an air inlet. Such a structure will increase the risk of exposing the internal parts of the motor device, making it easy for the circuit to be damaged by external static electricity or foreign matter intrusion. Furthermore, the high temperature of the heating chamber may also transfer a large amount of heat energy to the motor device, causing the internal temperature of the motor device to rise, thereby causing damage to the internal parts or reducing their lifespan.

[0005] In view of this, it is necessary to provide a self-cooling motor and a hot air circulation device applicable thereto to solve the defects of the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide a self-cooling motor and a hot air circulation device suitable for the same. The rotating shaft of the motor is extended to the high temperature of the heating chamber of the hot air circulation device through an impeller, and the radial air outlet and air inlet formed by the shell are matched to optimize the heat dissipation efficiency of the motor. The impeller is arranged between the motor and the heating chamber, which can block the radiant heat transmitted from the heating chamber, improve the temperature conditions inside the motor to extend the life of the internal parts, and reduce the probability of damage to the internal parts, so that the motor has higher stability. Furthermore, the impeller also includes a plurality of blades extending toward the space of the motor and arranged in a radial shape. When the impeller rotates with the rotating shaft of the motor, the blades on the impeller will drive the airflow to be discharged radially to form a negative pressure. The heat generated by the stator components in the space, such as the silicon steel sheet and the winding, will flow toward the negative pressure area and then be discharged radially, so as to achieve the heat dissipation efficiency of the self-cooling motor, and will not be easily affected by the heating chamber of the hot air circulation device.

[0007] Another object of the present invention is to provide a self-cooling motor and a hot air circulation device applicable thereto. The self-cooling motor is locked to the housing of the hot air circulation device through a plurality of locking parts on the housing, and the motor shaft extends through the impeller to the heating chamber of the housing. While the self-cooling motor is locked to the housing, the plurality of locking parts provide the function of locking and reinforcing the structure.

[0008] Another object of the present invention is to provide a self-cooling motor and a hot air circulation device applicable thereto. When the airflow enters the space from the air inlet formed between the bottom plate and the first end of the cylindrical baffle wall, the airflow further passes through the space along the axial direction and is then discharged from the air outlet formed between the impeller and the second end of the cylindrical baffle wall. Since the rotor assembly and the circuit board in the space are further provided with openings facing the axial direction, the airflow is facilitated to pass smoothly, and at the same time, the heat generated by the internal parts of the stator assembly and the circuit board is effectively dissipated, thereby further improving the heat dissipation efficiency of the self-cooling motor.

[0009] To achieve the aforementioned purpose, the present invention provides a self-cooling motor, including a housing, a stator assembly, a rotor assembly and an impeller. The housing includes a cylindrical baffle wall and a bottom plate, the cylindrical baffle wall and the bottom plate define a space, wherein the cylindrical baffle wall has a first end and a second end opposite to each other, an air inlet is formed between the bottom plate and the first end of the cylindrical baffle wall, and the air inlet faces the radial direction of the cylindrical baffle wall. The stator assembly is fixed to the housing and accommodated in the space. The rotor assembly is coupled to the stator assembly and includes a rotating shaft, wherein the rotating shaft extends axially to the outside of the housing. The impeller is fixed on the rotating shaft, and an air outlet is formed between the impeller and the second end of the cylindrical baffle wall, and the air outlet faces the radial direction of the cylindrical baffle wall, wherein when the rotating shaft of the rotor assembly drives the impeller to rotate synchronously, the impeller generates an airflow that enters the space from the air inlet in the radial direction, and is discharged through the air outlet in the radial direction.

[0010] In one embodiment, the impeller includes a first surface, a second surface and a plurality of blades, the first surface and the second surface are opposite to each other, the first surface faces the space, and the plurality of blades are disposed on the first surface and extend from the first surface toward the space.

[0011] In one embodiment, there is no through hole between any two adjacent leaves of the plurality of leaves.

[0012] In one embodiment, radially outwardly, the outer periphery of any one of the plurality of blades does not exceed the outer periphery of the rotor assembly.

[0013] In one embodiment, the self-cooling motor further comprises a circuit board, which is disposed adjacent to the first end of the cylindrical baffle wall and has an opening. The circuit board is axially upward and is located above the first end of the cylindrical baffle wall or is flush with the first end.

[0014] In one embodiment, along the radial direction outward, the outer peripheral edge of the bottom plate is flush with or exceeds the inner peripheral edge of the cylindrical retaining wall.

[0015] In one embodiment, the stator assembly further includes a coil, and the opening of the circuit board is spatially opposite to the coil.

[0016] In one embodiment, the rotor assembly includes a shell and a magnet group. The shell is fixed to the rotating shaft and has an opening facing the axial direction. The magnet group is arranged around the inner periphery of the shell.

[0017] In one embodiment, the shell further includes a plurality of locking components, which are assembled to lock and fix the self-cooling motor to a box, wherein the air outlet is located between the plurality of locking components.

[0018] In one embodiment, the shell further includes a plurality of connecting members connected between the first end of the cylindrical retaining wall and the bottom plate, wherein the air inlet is located between the plurality of connecting members.

[0019] In one embodiment, the impeller is made of metal material, low thermal conductivity material or ceramic material.

[0020] In one embodiment, the impeller does not have any through holes after being fixed to the rotating shaft.

[0021] In one embodiment, radially outwardly, the outer periphery of any blade does not exceed the outer periphery of the rotor assembly.

[0022] In order to achieve the aforementioned purpose, the present invention further provides a hot air circulation device, comprising a housing, a self-cooling motor and a fan assembly. The housing comprises a heating chamber. The self-cooling motor comprises a casing, a stator assembly, a rotor assembly and an impeller. The casing is fixed to the housing, and comprises a cylindrical baffle wall and a bottom plate, wherein the cylindrical baffle wall and the bottom plate define a space, wherein the cylindrical baffle wall has a first end and a second end opposite to each other. The bottom plate is connected to the first end of the cylindrical baffle wall, and an air inlet is formed between the bottom plate and the first end of the cylindrical baffle wall, wherein the air inlet faces the radial direction of the cylindrical baffle wall, wherein the second end faces the heating chamber. The stator assembly is fixed to the housing, and is accommodated in the space. The rotor assembly is connected to the stator assembly, and comprises a rotating shaft, wherein the rotating shaft extends axially to the housing. The impeller is fixed on the rotating shaft, located between the heating chamber and the cylindrical baffle wall, and adjacent to the second end of the cylindrical baffle wall, and an air outlet is formed between the impeller and the second end, and the air outlet faces the radial direction of the cylindrical baffle wall, wherein when the rotating shaft drives the impeller to rotate synchronously, the impeller generates airflow that enters the space from the air inlet in the radial direction and is discharged through the air outlet in the radial direction. The fan group is connected to the rotating shaft, and when the self-cooling motor drives the fan group to rotate, hot air circulates in the box.

[0023] In one embodiment, the impeller includes a first surface, a second surface and a plurality of blades. The first surface and the second surface are opposite to each other. The second surface faces the heating chamber. The plurality of blades are arranged on the first surface, extending from the first surface toward the space and arranged in a radial shape.

[0024] In one embodiment, the self-cooling motor further includes a circuit board having an opening, wherein the stator assembly includes a coil, and the opening of the circuit board is spatially opposite to the coil.

[0025] In one embodiment, the rotor assembly includes a shell and a magnet group, the shell is fixed to the rotating shaft, the magnet group is arranged around the inner periphery of the shell, and the impeller includes multiple blades, radially outward, and the outer periphery of any multiple blades does not exceed the outer periphery of the shell.

[0026] In one embodiment, the housing further includes a plurality of locking parts, which are assembled to lock and fix the self-cooling brushless motor to the box.

[0027] In one embodiment, the shell further includes a plurality of connecting members connected between the first end of the cylindrical retaining wall and the bottom plate, wherein the air inlet is located between the plurality of connecting members.

[0028] In one embodiment, the bottom plate, the cylindrical baffle wall, the impeller and the fan assembly are arranged in sequence along the axial direction.

[0029] The beneficial effect of the present invention is that the present invention provides a self-cooling motor and a hot air circulation device applicable thereto. The rotating shaft of the motor is extended to the high temperature of the heating chamber of the hot air circulation device through the impeller, and cooperates with the radial air outlet and air inlet formed by the shell to optimize the heat dissipation efficiency of the motor. The impeller is arranged between the motor and the heating chamber, which can block the radiant heat transmitted from the heating chamber, improve the temperature conditions inside the motor to extend the life of the internal parts, and reduce the probability of damage to the internal parts, so that the motor has a higher degree of stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A three-dimensional structural diagram of a self-cooling motor according to a preferred embodiment of the present invention is disclosed.

[0031] Figure 2 A structural exploded view of a self-cooling motor according to a preferred embodiment of the present invention is disclosed.

[0032] Figure 3 A structural exploded view of a self-cooling motor according to a preferred embodiment of the present invention is disclosed from another perspective.

[0033] Figure 4 A cross-sectional structural diagram of a self-cooling motor according to a preferred embodiment of the present invention is disclosed.

[0034] Figure 5 A schematic diagram of the airflow path of a self-cooling motor according to a preferred embodiment of the present invention is disclosed.

[0035] Figure 6 A schematic structural diagram of a hot air circulation device according to a preferred embodiment of the present invention is disclosed.

[0036] Fig. 7A as well as Figure 7BAn impeller according to a preferred embodiment of the present invention is disclosed.

[0037] Fig. 8A as well as Figure 8B A circuit board according to a preferred embodiment of the present invention is disclosed.

[0038] Fig. 9A as well as Fig. 9B A housing according to a preferred embodiment of the present invention is disclosed.

[0039] Fig.10 A cross-sectional structural diagram of a self-cooling motor according to another preferred embodiment of the present invention is disclosed.

[0040] Fig.11 A schematic diagram of the airflow path of a self-cooling motor according to another preferred embodiment of the present invention is disclosed.

[0041] The reference numerals are as follows:

[0042] 1.1a: Self-cooling motor

[0043] 2: Hot air circulation device

[0044] 10: Shell

[0045] 11: Tubular retaining wall

[0046] 11a: First End

[0047] 11b: Second end

[0048] 11c: Connectors

[0049] 12: Space

[0050] 13: Bottom plate

[0051] 14: Air inlet

[0052] 15: Air outlet

[0053] 16: Lock accessories

[0054] 17: Central

[0055] 18: Channel

[0056] 20: Stator assembly

[0057] 21: Coil

[0058] 30: Rotor assembly

[0059] 31: Shaft

[0060] 31a: First end

[0061] 31b: Second end

[0062] 31c: First locking element

[0063] 32: Shell

[0064] 33: Magnet Group

[0065] 34: Opening

[0066] 35: Fixing parts

[0067] 40, 40a: Impeller

[0068] 41: Side 1

[0069] 42: Side 2

[0070] 43: Blade

[0071] 44: Central opening

[0072] 50: Circuit board

[0073] 51: Opening

[0074] 52: Fixed opening

[0075] 53: Connectors

[0076] 60: Bearings

[0077] 70: Cabinet

[0078] 71: Heating chamber

[0079] 72: Depression

[0080] 80; Fan group

[0081] 81: Second locking element

[0082] A: Axial

[0083] F: Airflow path DETAILED DESCRIPTION

[0084] Some typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can be varied in various ways without departing from the scope of the present invention, and the description and drawings are essentially for illustrative purposes rather than for limiting the present invention.

[0085] Figure 1 A three-dimensional structural diagram of a self-cooling motor according to a preferred embodiment of the present invention is disclosed. Figure 2 A structural exploded view of a self-cooling motor according to a preferred embodiment of the present invention is disclosed. Figure 3 A structural exploded view of a self-cooling motor according to a preferred embodiment of the present invention is disclosed from another perspective. Figure 4 A cross-sectional structural diagram of a self-cooling motor according to a preferred embodiment of the present invention is disclosed. Figure 5A schematic diagram of the airflow path of a self-cooling motor according to a preferred embodiment of the present invention is disclosed. Figure 6 A schematic structural diagram of a hot air circulation device of a preferred embodiment of the present invention is disclosed. In this embodiment, a self-cooling motor (hereinafter referred to as the motor) 1 is, for example, used to drive a fan group 80 adjacent to a heating chamber 71 of a hot air circulation device 2. Facing the high temperature environment in the heating chamber 71, the self-cooling motor 1 also has the performance of self-heating and is not affected by the high temperature environment in the heating chamber 71. Of course, the application of the self-cooling motor 1 is not limited to this. In this embodiment, the self-cooling motor 1 is, for example, a brushless DC motor, and its structure includes a housing 10, a stator assembly 20, a rotor assembly 30, an impeller 40 and a circuit board 50. The housing 10 includes a cylindrical baffle wall 11 and a bottom plate 13. The cylindrical baffle 11 and the bottom plate 13 are arranged along the axial direction A and define a space 12, wherein the cylindrical baffle has a first end 11a and a second end 11b, the first end 11a and the second end 11b are opposite to each other, the bottom plate 13 is adjacent to the first end 11a of the cylindrical baffle 11, and an air inlet 14 is formed between the bottom plate 13 and the first end 11a of the cylindrical baffle 11, and the air inlet 14 faces the radial direction of the cylindrical baffle 11. In this embodiment, radially outward, the outer periphery of the bottom plate 13 is aligned with or exceeds the inner periphery of the cylindrical baffle 11. In other words, when the bottom plate 13 is viewed in the axial direction A, there is no air inlet 14. The cylindrical baffle 11 is, for example, a cylindrical baffle. The stator assembly 20 is fixed to the housing 10 and accommodated in the space 12. The rotor assembly 30 is coupled to the stator assembly 20 and includes a rotating shaft 31 extending along the axial direction A to the outside of the housing 10. The impeller 40 is fixed on the rotating shaft 31 and is adjacent to the second end 11b of the cylindrical baffle 11. An air outlet 15 is formed between the impeller 40 and the second end 11b of the cylindrical baffle 11, and the air outlet 15 faces the radial direction of the cylindrical baffle 11. When the rotating shaft 31 of the rotor assembly 30 drives the impeller 40 to rotate synchronously, the impeller 40 generates an air flow F that enters the space 12 from the air inlet 14 in the radial direction, passes through the space 12 along the axial direction A, and is discharged through the air outlet 15 in the radial direction. In this embodiment, the axial direction A is from the first end 11a to the second end 11b of the cylindrical baffle 11. In this way, the motor 1 can generate self-cooling heat dissipation performance, and the impeller 40 cooperates with the radial air inlet 14 and air outlet 15 formed by the housing 10 to further optimize the heat dissipation performance of the motor 1. On the other hand, the impeller 40 is disposed between the motor 1 and the heating chamber 71 to block the radiant heat from the heating chamber 71, thereby improving the temperature conditions inside the motor 1 to extend the life of the internal parts, while reducing the probability of damage to the internal parts, thereby making the motor 1 more stable.

[0086] Fig. 7A as well as Figure 7B The impeller of the preferred embodiment of the present invention is disclosed. Figures 1 to 5 , Fig. 7A as well as Figure 7BIn this embodiment, the impeller 40 further includes a first surface 41, a second surface 42 and a plurality of blades 43. The first surface 41 and the second surface 42 are opposite to each other. The first surface 41 faces the space 12. The plurality of blades 43 are arranged on the first surface 41, extending from the first surface 41 to the space 12, and arranged in a radial manner. There is no through hole between any two adjacent blades 43. Since the plurality of blades 43 of the impeller 40 extend toward the space 12 of the motor 1 and are arranged in a radial manner, when the impeller 40 rotates with the rotating shaft 31 of the motor 1, the blades 43 on the impeller 40 will drive the air flow F to be discharged radially through the air outlet 15 and form a negative pressure. The heat generated by the stator assembly 20 in the space 12, such as the silicon steel sheet and the winding, will flow along the axial direction A toward the negative pressure area, and then be discharged radially through the air outlet 15, so as to achieve the heat dissipation efficiency of the self-cooling motor 1, and is not easily affected by the heating chamber 71 of the hot air circulation device 2. In this embodiment, the impeller 40 may be, for example, formed of a metal material through a stamping process, and the impeller 40 and the blades 43 may be, for example, integrally formed. In one embodiment, the impeller 40 may be, for example, formed of a material with a low thermal conductivity coefficient to block the radiant heat transmitted from the heating chamber 71, and at the same time generate the airflow F through the plurality of blades 43. In other embodiments, the impeller 40 may be, for example, formed of a ceramic material. Of course, the present invention is not limited thereto. In addition, in this embodiment, the impeller 40 may include a central opening 44 and be fixed to the rotating shaft 31 through a fixing member 35; in one embodiment, the impeller 40 does not require a fixing member, and the impeller 40 is directly fixed to the rotating shaft 31 only through the rotating shaft 31, for example, through the central opening 44 and tightly matched with the central opening 44. It should be noted that the impeller 40 has no other perforations except the central opening 44. When the impeller 40 is fixed to the rotating shaft 31, the impeller 40 does not have any perforations. Therefore, when the impeller 40 rotates synchronously with the shaft 31 of the motor 1, the generated airflow F can effectively dissipate the heat generated inside the motor 1. The impeller 40 without other perforations can more effectively block the radiant heat transmitted from the heating chamber 71, improve the temperature conditions inside the motor 1 to extend the life of the internal parts, and at the same time reduce the probability of damage to the internal parts, so that the motor 1 has a higher stability.

[0087] Fig. 8A as well as Figure 8B A circuit board according to a preferred embodiment of the present invention is disclosed. Figures 1 to 5 , Fig. 8A as well as Figure 8B. In the present embodiment, the self-cooling motor 1 further comprises a circuit board 50, which is arranged adjacent to the first end 11a of the cylindrical baffle wall 11 and has an opening 51. In the present embodiment, the circuit board 50 can be connected to the stator assembly 20 and form an electrical connection with the outside through, for example, a conductive member 53. The outer periphery of the circuit board 50 is adjacent to the inner periphery of the cylindrical baffle wall 11a. The outer periphery of the circuit board 50 is further, for example, adjacent to the first end 11a of the cylindrical baffle wall 11, or upward along the axial direction A, and the circuit board 50 is located above the first end 11a of the cylindrical baffle wall 11 or is aligned with the first end 11a, so that the airflow F enters radially from the air inlet 14 and then passes through the space 12 along the axial direction A through the opening 51. Of course, the present invention is not limited thereto. The position and size of the circuit board 50 can be adjusted according to actual application requirements. In the present embodiment, the stator assembly 20 further comprises a coil 21, and the opening 51 of the circuit board 50 is spatially relative to the coil 21. Since the coil 21 of the stator assembly 20 is the main heat generating element, the airflow F can be directly directed to the coil 21 through the design of the opening 51 of the circuit board 50 , thereby effectively improving the heat dissipation performance of the self-cooling motor 1 .

[0088] Please refer to Figures 1 to 5 In this embodiment, the rotor assembly 30 of the self-cooling motor 1 includes a shell 32 and a magnet group 33. The shell 32 is fixed to the rotating shaft 31 and has an opening 34, facing the axial direction A. The magnet group 33 is arranged around the inner periphery of the shell 32. In this embodiment, the magnet group 33 is spatially opposite to the coil 21 of the stator assembly 20, and the shell 32 and the magnet group 33 are sleeved on the outer periphery of the coil 21. In this embodiment, the opening 34 of the shell 32 is also spatially opposite to the coil 21. Since the coil 21 of the stator assembly 20 is the main heat generating element, the opening 34 of the shell 32 can directly take the airflow F away from the coil 21, effectively improving the heat dissipation performance of the self-cooling motor 1. In other words, when the airflow F enters the space 12 from the air inlet 14 formed between the bottom plate 13 and the first end 11a of the cylindrical baffle 11, the airflow F further passes through the space 12 along the axial direction A, and then is discharged from the air outlet 15 formed between the impeller 40 and the second end 11b of the cylindrical baffle 11. Since the rotor assembly 30 in the space 12 is provided with an opening 34, and the circuit board 50 is provided with an opening 51, both facing the axial direction A, the airflow F can pass smoothly, and at the same time, the heat generated by the internal parts of the stator assembly 20 and the circuit board 50 can be effectively dissipated, so as to further improve the heat dissipation performance of the self-cooling motor 1.

[0089] Fig. 9A as well as Fig. 9B The present invention discloses a housing according to a preferred embodiment of the present invention. Figures 1 to 6 , Fig. 9A as well as Fig. 9B. In this embodiment, the housing 10 further includes a plurality of locking accessories 16, which are assembled to lock and fix the self-cooling motor 1 to the box 70 of the hot air circulation device 2. In this embodiment, the housing 10 includes, for example, three locking accessories 16, which are equidistantly arranged around the outer periphery of the cylindrical retaining wall 11 and protrude from the second end 11b of the cylindrical retaining wall 11. In other embodiments, the arrangement and number of the locking accessories 16 can be adjusted according to actual application requirements, and the present invention is not limited thereto. In this embodiment, since the self-cooling motor 1 is locked to the box 70 of the hot air circulation device 2 by the plurality of locking accessories 16 on the housing 10, and the rotating shaft 31 of the motor 1 is extended to the heating chamber 71 of the box 70 through the impeller 40. Therefore, while the self-cooling motor 1 is locked to the box 70, the plurality of locking accessories 16 provide the function of locking and reinforcing the structure, and the air outlet 15 at the second end 11b of the cylindrical retaining wall 11 is arranged between the plurality of locking accessories 16, which has the function of guiding the direction of the airflow. In addition, the shell 10 also includes a plurality of connectors 11c, which are connected between the first end 11a of the cylindrical baffle wall 11 and the bottom plate 13, wherein the air inlet 14 may be, for example, located between the plurality of connectors 11c. In addition to providing the function of connection, the plurality of connectors 11c also have the function of guiding the direction of airflow. Furthermore, in this embodiment, a plurality of locking accessories 16 may also protrude from the first end 11a of the cylindrical baffle wall 11 to provide a connection between the bottom plate 13 and the cylindrical baffle wall 11, wherein the air inlet 14 may be, for example, located between the locking accessories 16 and the connector 11c to provide the function of guiding the direction of airflow. Of course, the arrangement, quantity and setting method of the locking accessories 16 and the connector 11c may be adjusted according to the actual application requirements, and the present invention is not limited thereto and will not be elaborated on.

[0090] Please refer to Figures 1 to 5 , Fig. 9A as well as Fig. 9B . In the present embodiment, the housing 10, for example, has a central portion 17 and a channel 18, and the channel 18 passes through the central portion 17. The stator assembly 20 may be, for example, annularly fixed to the outer periphery of the central portion 17, and may include, for example, a snap-fit ​​element that engages a fixing opening 52 of the circuit board 50, so that the circuit board 50 is connected to the stator assembly 20. The rotating shaft 31 of the rotor assembly 30 may be connected to the stator assembly 20, for example, through a bearing 60. In the present embodiment, the bearing 60 is, for example, disposed in the channel 18, and the rotating shaft 31 passes through the channel 18 and the bearing 60, so as to realize the connection between the stator assembly 20 and the rotor assembly 30. Of course, the present invention is not limited thereto. In the present embodiment, the central portion 17 is connected to the bottom plate 13, and the channel 18 passes through the bottom plate 13, for example, so that the bearing 60 is assembled to the channel 18 and connected to the first end 31a adjacent to the rotating shaft 31. In this embodiment, the bottom plate 13 has no other holes except the channel 18. When the bearing 60 is disposed in the channel 18, the bottom plate 13 can prevent the circuit board 50 from being exposed to cause static electricity to damage electronic parts or foreign matter from invading and causing circuit short circuit or open circuit.

[0091] reference Figures 1 to 6. As mentioned above, the self-cooling motor 1 of the present invention is more suitable for a thermal circulation device 2. Therefore, the present invention further discloses a hot air circulation device 2, whose structure includes a box body 70, a self-cooling motor 1 and a fan group 80. In this embodiment, the box body 70 includes a heating chamber 71 and a recessed portion 72. The recessed portion 72 is connected to the heating chamber 71, and the self-cooling motor 1 and the fan group 80 are arranged in the recessed portion 72. In this embodiment, the self-cooling motor 1 includes a housing 10, a stator assembly 20, a rotor assembly 30 and an impeller 40. In this embodiment, the housing 10 is fixed to the box body 70, and includes a cylindrical baffle wall 11, a space 12 and a bottom plate 13. The bottom plate 13, the cylindrical baffle wall 11, the impeller 40 and the fan group 80 are arranged in sequence along the axial direction A. The space 12 is located between the cylindrical baffle 11 and the bottom plate 13, wherein the cylindrical baffle 11 has a first end 11a and a second end 11b, and the first end 11a and the second end 11b are opposite to each other. The bottom plate 13 is adjacent to the first end 11a of the cylindrical baffle 11, and an air inlet 14 is formed between the bottom plate 13 and the first end 11a of the cylindrical baffle 11, and the air inlet 14 faces the radial direction of the cylindrical baffle 11, wherein the second end 11b faces the heating chamber 71. The stator assembly 20 is fixed to the housing 10 and accommodated in the space 12. The rotor assembly 30 is connected to the stator assembly 20 and includes a rotating shaft 31, wherein the rotating shaft 31 extends to the box body 70 along the axial direction A. In this embodiment, the rotating shaft 31, for example, has a first end 31a and a second end 31b opposite to each other, wherein the first end 31a is connected to the housing 10, and the second end 31b extends to the box body 70. The impeller 40 is fixed between the first end 31a and the second end 31b of the rotating shaft 31, located between the heating chamber 71 and the cylindrical baffle wall 11, and adjacent to the second end 11b of the cylindrical baffle wall 11. An air outlet 15 is formed between the impeller 40 and the second end of the cylindrical baffle wall 11, and the air outlet 15 faces the radial direction of the cylindrical baffle wall 11. When the rotating shaft 31 of the rotor assembly 30 drives the impeller 40 to rotate synchronously, the impeller 40 generates an airflow that enters the space 12 from the air inlet 14 in the radial direction, passes through the space 12 along the axial direction A, and is discharged through the air outlet 15 in the radial direction. In addition, in this embodiment, the rotating shaft 31 also includes a first locking element 31c, such as a thread, adjacent to the second end 31b. The fan assembly 80 also includes a second locking element 81, such as a nut. The fan assembly 80 can be fixed to the second end 31b of the rotating shaft 31 by engaging the first locking element 31c and the second locking element 81 with each other. When the self-cooling motor 1 drives the fan assembly 80 to rotate, the fan assembly 80 can circulate hot air to the box 70. In this embodiment, the shaft 31 of the self-cooling motor 1 extends through the impeller 40 to the heating chamber 71 of the hot air circulation device 2, and cooperates with the radial air outlet 15 and the air inlet 14 formed by the housing 10 to optimize the heat dissipation performance of the motor 1.Since the impeller 40 is disposed between the motor 1 and the heating chamber 71, it can block the radiant heat from the heating chamber 71, improve the temperature conditions inside the motor 1 to extend the life of the internal parts, and reduce the probability of damage to the internal parts, so that the motor 1 has a higher stability. On the other hand, the highly stable motor 1 drives the fan assembly 80 to rotate in the heating chamber 71 through the rotating shaft 31, which can make the circulation of hot air in the heating chamber 71 more uniform, further improving the heating quality of the food. Of course, the way in which the self-cooling motor 1 of the present invention is combined with the hot air circulation device 2 can be adjusted according to the actual application requirements, and it will not be repeated here.

[0092] Fig.10 A cross-sectional structural diagram of a self-cooling motor according to another preferred embodiment of the present invention is disclosed. Fig.11 The present invention discloses a schematic diagram of the airflow path of a self-cooling motor according to another preferred embodiment of the present invention. Figure 1 The impeller 40a is similar to the self-cooling motor 1 shown in FIG. 9 , and the same element numbers represent the same elements, structures and functions, which will not be described in detail here. In this embodiment, radially outward, the outer periphery of any blade 43 of the impeller 40a does not exceed the outer periphery of the shell 32 of the rotor assembly 30. Since the impeller 40a is fixed to the rotating shaft 31, the impeller 40a does not have other through holes. Therefore, when the impeller 40a rotates synchronously with the rotating shaft 31 of the motor 1a, the airflow F generated can effectively dissipate the heat generated inside the motor 1a. The impeller 40a without other through holes can more effectively block external radiant heat, improve the temperature conditions inside the motor 1a to extend the life of the internal parts, and reduce the probability of damage to the internal parts, so that the motor 1a has a higher stability.

[0093] In summary, the present invention provides a self-cooling motor and a hot air circulation device applicable thereto. The rotating shaft of the motor is extended to the high temperature of the heating chamber of the hot air circulation device through an impeller, and the radial air outlet and air inlet formed by the shell are coordinated to optimize the heat dissipation efficiency of the motor. The impeller is arranged between the motor and the heating chamber, which can block the radiant heat transmitted from the heating chamber, improve the temperature conditions inside the motor to extend the life of the internal parts, and reduce the probability of damage to the internal parts, so that the motor has a higher stability. Furthermore, the impeller includes a plurality of blades extending toward the space of the motor and arranged in a radial shape. When the impeller rotates with the rotating shaft of the motor, the blades on the impeller will drive the airflow to be discharged radially to form a negative pressure. The heat generated by the stator components in the space, such as the silicon steel sheet and the winding, will flow toward the negative pressure area and then be discharged radially, so as to achieve the heat dissipation efficiency of the self-cooling motor, and is not easily affected by the heating chamber of the hot air circulation device. In addition, the self-cooling motor is locked to the box of the hot air circulation device through a plurality of locking accessories on the shell, and the rotating shaft of the motor is extended to the heating chamber of the box through the impeller. While the self-cooling motor is locked in the box, multiple locking accessories provide the function of locking and reinforcing the structure. Through the air inlet and air outlet at the two corresponding ends of the cylindrical baffle wall, the air flow can be sucked in and discharged in the radial direction. On the other hand, when the air flow enters the space from the air inlet formed between the bottom plate and the first end of the cylindrical baffle wall, the air flow passes through the space axially and is discharged from the air outlet formed between the impeller and the second end of the cylindrical baffle wall. Since the rotor assembly and the circuit board in the space are further provided with axially oriented openings, the air flow can pass smoothly, and at the same time effectively dissipate the heat generated by the stator assembly and the components on the circuit board, further improving the heat dissipation efficiency of the self-cooling motor.

[0094] The present invention can be modified in various ways by those skilled in the art, but all of them are within the protection of the appended claims.

Claims

1. A self-cooling motor, comprising: A housing, comprising a cylindrical baffle and a bottom plate, wherein the cylindrical baffle and the bottom plate are arranged along an axial direction and define a space, wherein the cylindrical baffle has a first end and a second end opposite to each other, an air inlet is formed between the bottom plate and the first end, and the air inlet faces a radial direction of the cylindrical baffle; A stator assembly is fixed to the housing and accommodated in the space; a rotor assembly coupled to the stator assembly and comprising a rotating shaft extending along the axial direction to the outside of the housing, and an impeller fixed on the rotating shaft, forming an air outlet between the impeller and the second end, the air outlet facing the radial direction of the cylindrical retaining wall, wherein when the rotating shaft drives the impeller to rotate synchronously, the impeller generates an airflow, the airflow enters the space through the air inlet in the radial direction, and is discharged through the air outlet in the radial direction; Along the radial direction outward, an outer peripheral edge of the impeller at least aligns with or exceeds an inner peripheral edge of the cylindrical baffle wall.

2. The self-cooling motor as claimed in claim 1, wherein the impeller comprises a first surface, a second surface and a plurality of blades, the first surface and the second surface are opposite to each other, the first surface faces the space, and the plurality of blades are disposed on the first surface.

3. The self-cooling motor as claimed in claim 2, wherein there is no through hole between any two adjacent blades of the plurality of blades.

4. The self-cooling motor as claimed in claim 2, wherein along the radial direction outward, an outer periphery of any one of the plurality of blades does not exceed an outer periphery of the rotor assembly. 5 . The self-cooling motor as claimed in claim 1 , wherein along the radial direction outward, an outer peripheral edge of the bottom plate is aligned with or exceeds an inner peripheral edge of the cylindrical retaining wall.

6. The self-cooling motor as claimed in claim 1, further comprising a circuit board, which is located above the first end of the cylindrical retaining wall or is flush with the first end along the axial direction upward.

7. The self-cooling motor as claimed in claim 1, wherein the rotor assembly comprises a shell and a magnet group, the shell is fixed to the rotating shaft and has an opening facing the axial direction, and the magnet group is arranged around the inner periphery of the shell.

8. The self-cooling motor as claimed in claim 1, wherein the housing further comprises a plurality of locking components assembled to lock and fix the self-cooling motor to a box, wherein the air outlet is located between the plurality of locking components.

9. The self-cooling motor as claimed in claim 1, wherein the housing further comprises a plurality of connecting members connected between the first end of the cylindrical baffle wall and the bottom plate, wherein the air inlet is located between the plurality of connecting members. 10 . The self-cooling motor as claimed in claim 1 , wherein the impeller is made of a metal material, a low thermal conductivity material or a ceramic material.

11. The self-cooling motor as claimed in claim 1, wherein the impeller does not have any through hole after being fixed to the rotating shaft.

12. A hot air circulation device, comprising: A box body including a heating chamber; A self-cooling motor, comprising: A shell, fixed to the box body, and comprising a cylindrical baffle and a bottom plate, wherein the cylindrical baffle and the bottom plate define a space, wherein the cylindrical baffle has a first end and a second end opposite to each other, an air inlet is formed between the bottom plate and the first end, the air inlet faces a radial direction of the cylindrical baffle, wherein the second end faces the heating chamber; A stator assembly is fixed to the housing and accommodated in the space; a rotor assembly coupled to the stator assembly and comprising a rotating shaft extending along an axial direction to the heating chamber, and an impeller, fixed on the rotating shaft, located between the heating chamber and the cylindrical baffle wall, an air outlet is formed between the impeller and the second end, the air outlet faces the radial direction of the cylindrical baffle wall, wherein when the rotating shaft drives the impeller to rotate synchronously, the impeller generates an airflow, the airflow enters the space through the air inlet in the radial direction, and is discharged through the air outlet in the radial direction; Along the radial direction outward, an outer peripheral edge of the impeller at least cuts into or exceeds an inner peripheral edge of the cylindrical baffle wall, and A fan group is connected to the rotating shaft, and when the self-cooling motor drives the fan group to rotate, hot air circulates in the heating chamber.

13. The hot air circulation device as claimed in claim 12, wherein the impeller comprises a first surface, a second surface and a plurality of blades, the first surface and the second surface are opposite to each other, the second surface faces the heating chamber, and the plurality of blades extend from the first surface toward the space.

14. The hot air circulation device as claimed in claim 12, wherein the self-cooling motor further comprises a circuit board having an opening, wherein the stator assembly comprises a coil, and the opening of the circuit board is spatially opposite to the coil.

15. A hot air circulation device as described in claim 12, wherein the rotor assembly includes a shell and a magnet group, the shell is fixed to the rotating shaft, and the magnet group is arranged around the inner periphery of the shell, wherein the impeller includes a plurality of blades, and along the radial direction outward, an outer periphery of any of the plurality of blades does not exceed an outer periphery of the shell. 16 . The hot air circulation device as claimed in claim 12 , wherein the housing further comprises a plurality of locking components assembled to lock and fix the self-cooling motor to the box.

17. The hot air circulation device as claimed in claim 12, wherein the shell further comprises a plurality of connecting members connected between the first end of the cylindrical retaining wall and the bottom plate, wherein the air inlet is located between the plurality of connecting members.

18. The hot air circulation device according to claim 12, wherein: The bottom plate, the cylindrical baffle wall, the impeller and the fan assembly are arranged in sequence along the axial direction.

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