External rotor motor with heat dissipation function

Abstract

The outer rotor motor comprises a stator and a rotor, the rotor comprises a rotor shell with a containing cavity formed in the top face, a magnet yoke ring is arranged on the inner circumferential wall of the containing cavity, the stator comprises a stator core wound with a coil and a stator shell closing an opening of the containing cavity, the stator core is located in the containing cavity, and the magnet yoke ring is arranged on the inner circumferential wall of the containing cavity. A plurality of blades are arranged on the bottom wall of the rotor shell in the circumferential direction, a first air hole for communicating the containing cavity with the outside is formed between every two adjacent blades, the stator shell is provided with an annular protruding eave extending downwards, and the protruding eave and the projection part of the side wall of the containing cavity on the symmetry plane coincide. And a plurality of second air holes for communicating the accommodating cavity with the outside are formed in the convex eave. The motor has the advantages that the first air hole is located at the bottom of the motor, the second air hole is located at the upper part of the motor, and the heat dissipation air channel passes through the coil to dissipate heat of the coil, so that the heat dissipation efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of electromechanics, and particularly relates to an outer rotor motor with heat dissipation. Background Art

[0002] In order to wash clothes more hygienically, there are many underwear washing machines on the existing market. Since they are used to wash small items and are mostly the second washing machine at home, it is necessary to make the small washing machine thinner and reduce the manufacturing cost at the same time.

[0003] When the motor rotates, internal components such as coils will also generate heat. In order to better dissipate heat from the motor in a narrow space, existing outer rotor motors also have blades on the outer rotor, and the rotation of the outer rotor drives the blades to rotate synchronously. However, the distance between the blades is relatively large. For example, the outer rotor DC brushless motor for heat dissipation disclosed in Chinese Patent Publication No. CN216699696U all mentions using the rotation of the blades to increase the contact area between the outside air and the air inside the motor to facilitate heat dissipation inside the motor. However, none of them provide a complete heat dissipation air duct, and the stator end face opposite to the rotor end face where the blades are located is basically in a closed state, and the air drawn into the motor by the blades cannot form good circulation, resulting in a significant reduction in heat dissipation efficiency. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an outer rotor motor with heat dissipation, which can effectively solve the problem of low heat dissipation efficiency of the inner and outer rotor motors of existing washing machines.

[0005] In order to solve the above technical problems, the utility model is realized through the following technical solutions:

[0006] An outer rotor motor with heat dissipation includes a stator and a rotor. The rotor includes a rotor shell with a receiving cavity opened on the top surface. A magnetic yoke ring is provided on the inner peripheral wall of the receiving cavity. The stator includes a stator core wound with coils and a stator shell closing the opening of the receiving cavity. The stator core is located inside the receiving cavity. A plurality of blades are circumferentially provided on the bottom wall of the rotor shell. A first air vent communicating the receiving cavity with the outside is formed between adjacent blades. The stator shell is provided with a downwardly extending annular flange. The projection of the flange on the side wall of the receiving cavity in the symmetry plane partially coincides. A plurality of second air vents communicating the receiving cavity with the outside are opened on the flange.

[0007] In the above outer rotor motor with heat dissipation, the flange surrounds the outside of the side wall of the receiving cavity.

[0008] In the above outer rotor motor with heat dissipation, the projection of the second air vent on the side wall of the receiving cavity in the symmetry plane does not coincide.

[0009] In the above-mentioned outer rotor motor with heat dissipation, the stator core includes a fixing part and a winding part. The fixing part is fixed on the stator housing, the coil is wound on the winding part, and the winding part is located directly above the blade.

[0010] In the above-mentioned outer rotor motor with heat dissipation, the angle between the blade and the horizontal plane is an acute angle, and the projections of adjacent blades on the horizontal plane partially overlap.

[0011] In the above-mentioned outer rotor motor with heat dissipation, the yoke ring is provided with a positioning part protruding radially outward, and a positioning groove adapted to the positioning part is provided on the inner side wall of the accommodating cavity.

[0012] In the above-mentioned outer rotor motor with heat dissipation, the outer rotor motor with heat dissipation further includes a motor shaft. A fixing hole is opened at the center of the bottom of the accommodating cavity, a rotating hole is provided at the center of the stator housing, the bottom end of the motor shaft is fixed in the fixing hole, the top end of the motor shaft passes through the rotating hole, and the motor shaft is rotatably connected to the rotating hole.

[0013] In the above-mentioned outer rotor motor with heat dissipation, a butting part protruding towards the center direction is provided in the middle of the rotating hole. Bearings are provided in the rotating holes above and below the butting part. The end face of the bearing abuts against the butting part, and the motor shaft passes through the bearing.

[0014] Compared with the prior art, the advantages of the present utility model are:

[0015] A heat dissipation air duct is formed through the first ventilation hole at the bottom of the motor and the second ventilation hole at the upper part of the motor, solving the problem of low heat dissipation efficiency of the inner and outer rotor motors of the current washing machine. By using the first ventilation hole through which the accommodating cavity formed between adjacent blades communicates with the outside, when the motor rotates, the blades drive the air to flow through the first ventilation hole, causing a negative pressure or an increase in pressure in the accommodating cavity. And by opening a second ventilation hole on the eaves of the stator housing located at the upper part of the motor, when a negative pressure or an increase in pressure occurs in the accommodating cavity, the outside air can flow in or out, thus cooperating with the first ventilation hole to form a complete heat dissipation air duct. And since the first ventilation hole is located at the bottom of the motor and the second ventilation hole is located at the upper part of the motor, the heat dissipation air duct will pass through the coil to dissipate heat from the coil, improving the heat dissipation efficiency of the motor. And by opening the second ventilation hole on the eaves extending downward on the stator housing, the structure of the top surface of the stator housing will not be damaged, there is no need to change the original structure of the top of the stator housing, and thus there is no need to change the installation positions of components such as the circuit board on the stator housing, reducing the design difficulty; when water droplets fall above the motor, it is not easy for the water droplets to enter the motor through the second ventilation hole.

[0016] Further, the eaves surround the outside of the side wall of the accommodation cavity. The eaves can play a role in positioning the rotor housing during the assembly of the rotor housing and the stator housing. The eaves surround the outside of the side wall of the accommodation cavity, avoiding the eaves occupying the space inside the accommodation cavity.

[0017] Further, the projection of the second ventilation hole on the symmetry plane of the side wall of the accommodation cavity does not coincide. This avoids the side wall of the accommodation cavity obstructing the air flowing through the second ventilation hole, making the air flow smoother.

[0018] Further, the stator core includes a fixing portion and a winding portion. The fixing portion is fixed on the stator housing, the coil is wound on the winding portion, and the winding portion is located directly above the blade. This allows the air flow generated by the rotation of the blade to better cover the winding portion of the stator core, dissipating heat for the coil on the winding portion.

[0019] Further, the angle between the blade and the horizontal plane is an acute angle, and the projections of adjacent blades on the horizontal plane partially overlap. This avoids water droplets directly entering the motor from the vertical direction through the first ventilation hole, improving the waterproof performance.

[0020] Further, the yoke ring is provided with a positioning portion protruding radially outward, and a positioning groove adapted to the positioning portion is provided on the inner side wall of the accommodation cavity. Through the cooperation of the positioning portion of the yoke ring and the positioning groove of the accommodation cavity, the yoke ring can be stably fixed in the accommodation cavity.

[0021] Further, the outer rotor motor with heat dissipation further includes a motor shaft. A fixing hole is opened at the center of the bottom of the accommodation cavity, a rotating hole is provided at the center of the stator housing, the bottom end of the motor shaft is fixed in the fixing hole, the top end of the motor shaft passes through the rotating hole, and the motor shaft is rotatably connected to the rotating hole. This allows the motor shaft to rotate synchronously with the rotor and maintains the rotational connection between the motor shaft and the stator housing.

[0022] Further, a butting portion protruding towards the center direction is provided in the middle of the rotating hole. Bearings are provided in the rotating hole above and below the butting portion. The end face of the bearing abuts against the butting portion, and the motor shaft passes through the bearing. The protruding butting portion provides axial positioning for the bearing and also keeps the axial position of the motor shaft and the stator housing relatively fixed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of an outer rotor motor with heat dissipation according to the present invention;

[0024] Figure 2 is a perspective view of the rotor housing in the present invention;

[0025] Figure 3 is a perspective view of the stator housing in the present invention;

[0026] Figure 4 It is a cross-sectional view of the stator housing in the present utility model;

[0027] Figure 5 It is a cross-sectional view of an outer-rotor motor with heat dissipation in the present utility model;

[0028] Figure 6 It is an exploded view of an outer-rotor motor with heat dissipation in the present utility model.

[0029] The reference numerals are:

[0030] Stator 10, coil 11, stator core 12, fixing part 121, winding part 122, stator housing 13, convex eaves 14, second ventilation holes 15, rotating holes 16, abutting part 17;

[0031] Rotor 20, rotor housing 21, accommodating cavity 22, yoke ring 23, positioning part 231, blades 24, first ventilation holes 25, positioning grooves 26, fixing holes 27;

[0032] Motor shaft 30;

[0033] Bearing 40. Specific embodiments

[0034] An outer-rotor 20 motor with heat dissipation includes a stator 10 and a rotor 20. The rotor 20 includes a rotor housing 21 with an accommodating cavity 22 opened on the top surface. A yoke ring 23 is provided on the inner peripheral wall of the accommodating cavity 22. The stator 10 includes a stator core 12 wound with a coil 11 and a stator housing 13 that closes the opening of the accommodating cavity 22. The stator core 12 is located inside the accommodating cavity 22. A plurality of blades 24 are provided on the bottom wall of the rotor housing 21 along the circumferential direction. First ventilation holes 25 communicating the accommodating cavity 22 with the outside are formed between adjacent blades 24. The stator housing 13 is provided with a downward-extending annular convex eaves 14. The projection of the convex eaves 14 on the side wall of the accommodating cavity 22 in the symmetry plane partially overlaps. A plurality of second ventilation holes 15 communicating the accommodating cavity 22 with the outside are opened on the convex eaves 14.

[0035] A heat dissipation air duct is formed by a first ventilation hole 25 at the bottom of the motor and a second ventilation hole 15 at the upper part of the motor, solving the problem of low heat dissipation efficiency of the inner and outer rotor 20 motors of the current washing machine. By using the first ventilation hole 25 where the accommodation cavity 22 formed between adjacent blades 24 communicates with the outside, when the motor rotates, the blades 24 drive the air to flow through the first ventilation hole 25, causing a negative pressure or an increase in pressure in the accommodation cavity 22. And a second ventilation hole 15 is opened on the eaves 14 of the stator housing 13 located at the upper part of the motor, so that when a negative pressure or an increase in pressure occurs in the accommodation cavity 22, the outside air can flow in or out, thus cooperating with the first ventilation hole 25 to form a complete heat dissipation air duct. And since the first ventilation hole 25 is located at the bottom of the motor and the second ventilation hole 15 is located at the upper part of the motor, the heat dissipation air duct will pass through the coil 11 to dissipate heat from the coil 11. And opening the second ventilation hole 15 on the downward-extending eaves 14 of the stator housing 13 will not damage the structure of the top surface of the stator housing 13, without changing the original top structure of the stator housing 13, and thus there is no need to change the installation positions of components such as the circuit board on the stator housing 13, reducing the design difficulty; when water droplets fall above the motor, it is not easy for the water droplets to enter the motor through the second ventilation hole 15.

[0036] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "attachment", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection, an electrical connection, or a communication with each other; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0040] Refer to Figures 1 to 6 The following is an embodiment of an outer rotor 20 motor with heat dissipation in the present utility model. An outer rotor 20 motor with heat dissipation includes a stator 10, a rotor 20, and a motor shaft 30. The rotor 20 includes a rotor housing 21 with a receiving cavity 22 formed on its top surface. Since the rotor 20 needs to rotate relatively, the rotor housing 21 is basically cylindrical and has an open top. A yoke ring 23 is provided on the inner peripheral wall of the receiving cavity 22, and a plurality of magnets are arranged equidistantly along the circumferential direction on the yoke ring 23. The stator 10 includes a stator core 12 wound with a coil 11 and a stator housing 13 that closes the opening of the receiving cavity 22. The stator core 12 is located inside the receiving cavity 22 and is fixed to the stator housing 13. In this way, after the coil 11 is energized, the rotor housing 21 and the yoke ring 23 can rotate relative to the stator core 12 and the stator housing 13. A gap should be left between the stator core 12 and the yoke ring 23 to prevent friction between the yoke ring 23 and the stator core 12 when the yoke ring 23 rotates. The bottom end of the motor shaft 30 is fixed to the bottom of the receiving cavity 22 and is located at the central position of the rotor housing 21. The top of the motor shaft 30 passes through the stator housing 13 and extends outward for connection with a driving member.

[0041] On the bottom wall of the rotor housing 21, a plurality of vanes 24 are circumferentially arranged. The vanes 24 are all arranged in an annular array around the rotation axis of the rotor housing 21 so as to keep the rotor housing 21 balanced when the rotor housing 21 rotates. A first ventilation hole 25 through which the accommodation chamber 22 communicates with the outside is formed between adjacent vanes 24. An annular projection 14 extending downward is provided on the stator housing 13. The projection 14 partially coincides with the projection of the side wall of the accommodation chamber 22 on the symmetry plane. The so-called symmetry plane is the plane passing through the center line of the rotor rotation. The rotors on both sides of the symmetry plane are symmetrically arranged. When installing the rotor 20 and the stator 10, the projection 14 can also play a role in positioning the rotor housing 21. In order to prevent the projection 14 from hindering the rotation of the rotor housing 21, a gap is left between the projection 14 and the rotor housing 21. A plurality of second ventilation holes 15 through which the accommodation chamber 22 communicates with the outside are formed in the projection 14. The outside air can flow into the accommodation chamber 22 through the first ventilation hole 25 as the vanes 24 rotate, and then flow out through the second ventilation hole 15, thus forming a complete heat dissipation air duct. This will help to quickly take away the heat generated by the electrical components in the accommodation chamber 22 and greatly improve the heat dissipation efficiency. Of course, it is also possible to rotate the vanes 24 to allow the outside air to flow in through the second ventilation hole 15 and flow out through the first ventilation hole 25. If the motor in this embodiment is applied to an environment with water such as a washing machine, for the sake of safety, the first ventilation hole 25 is still used for air intake and the second ventilation hole 15 is used for air outlet. Since the first ventilation hole 25 is located at the bottom of the motor, water flow is not easy to enter the accommodation chamber 22 through the first ventilation hole 25, and the air flow blows out through the second ventilation hole 15, which also makes it difficult for water flow to enter the accommodation chamber 22 through the second ventilation hole 15.

[0042] Furthermore, the projection 14 surrounds the outside of the side wall of the accommodation chamber 22 to prevent the projection 14 from occupying the space inside the accommodation chamber 22. In order to ensure the ventilation efficiency of the second ventilation hole 15, the projection of the second ventilation hole 15 on the symmetry plane does not coincide with the side wall of the accommodation chamber 22, which reduces the blockage of the second ventilation hole 15 by the side wall of the accommodation chamber 22 and enables the hot air in the accommodation chamber 22 to flow out through the second ventilation hole 15 as soon as possible.

[0043] The stator core 12 includes a fixing part 121 and a winding part 122. The fixing part 121 is used for fixing to the stator housing 13. The fixing part 121 can be a fixing hole 27. Correspondingly, a protruding fixing column is provided at the center of the stator housing 13. The fixing hole 27 of the stator core 12 is sleeved with the fixing column of the stator housing 13 to realize the fixed connection between the two. The winding part 122 is a plurality of fixing frames radially distributed in a radial direction with the center of the stator core 12 as the center. The coil 11 can be wound on the fixing frames, thus stabilizing the shape of the coil 11. The winding part 122 is located directly above the vanes 24. The air flow generated when the vanes 24 rotate blows through the winding part 122, blowing away the heat generated after the coil 11 is energized and quickly cooling the coil 11 to improve the heat dissipation efficiency.

[0044] In order to minimize the probability of water droplets entering the accommodation cavity 22 from the first ventilation holes 25, the projected parts of adjacent blades 24 overlap on the horizontal plane, and the angle between the blade 24 and the horizontal plane is an acute angle. The blade 24 is in a sheet shape, so that while it is easier to generate air flow, it can also prevent water droplets from passing through the first ventilation holes 25 from the outside into the accommodation cavity 22 axially.

[0045] In this embodiment, the yoke ring 23 and the rotor housing 21 are separately manufactured and then assembled, which can improve the assembly efficiency. The yoke ring 23 is provided with a positioning portion 231 protruding radially outward. The inner side wall of the accommodation cavity 22 is provided with a positioning groove 26 adapted to the positioning portion 231. Thus, as long as the yoke ring 23 is inserted into the accommodation cavity 22 circumferentially and the positioning portion 231 is inserted into the positioning groove 26, the connection between the yoke ring 23 and the rotor housing 21 can be completed. Glue or other means can be used to further fix the yoke ring 23 and the rotor housing 21 completely.

[0046] For the motor shaft 30, a fixing hole 27 is opened at the center of the bottom of the accommodation cavity 22. The bottom of the motor shaft 30 is fixed in the fixing hole 27. A rotating hole 16 is provided at the center of the stator housing 13. The top of the motor shaft 30 passes through the rotating hole 16 and extends out to be connected with the driving member. The motor shaft 30 is rotatably connected with the rotating hole 16. In this way, the motor shaft 30 can rotate synchronously with the rotor housing 21 and rotate relative to the stator housing 13.

[0047] Furthermore, in order to fix the axial positions of the motor shaft 30 and the stator housing 13, a butting portion 17 protruding towards the center direction is provided in the middle of the rotating hole 16. The inner diameter of the butting portion 17 is larger than the outer diameter of the motor shaft 30 to avoid contact and friction between the butting portion 17 and the motor shaft 30. Bearings 40 are provided in the rotating hole 16 above and below the butting portion 17. The end faces of the bearings 40 abut against the butting portion 17. The motor shaft 30 passes through all the bearings 40. That is, the rotation connection between the motor shaft 30 and the stator housing 13 is realized through the bearings 40, and the two bearings 40 abut against the butting portion 17 from two axial directions respectively to axially position the motor shaft 30 and the stator housing 13.

[0048] With the outer rotor 20 motor having the above structure, after the motor coil 11 is energized, the rotor 20 drives the motor shaft 30 to rotate. At the same time, the blades 24 at the bottom of the rotor housing 21 disturb the air, causing the outside air to enter the accommodation chamber 22 through the first ventilation holes 25. The air flow passes through the stator core 12 and takes out the heat generated by the coil 11 from the second ventilation holes 15, realizing the heat dissipation of the outer rotor 20 motor. In the technical solution of the present invention, by providing the first ventilation holes 25 at the bottom of the rotor housing 21 and the second ventilation holes 15 at the upper part of the motor, a heat dissipation air duct is formed, enabling the outside air to quickly pass through and take away the heat inside the motor. Moreover, due to the positions of the first ventilation holes 25 and the second ventilation holes 15, it also has a certain degree of waterproofness, which can prevent splashing water from directly entering the motor interior.

[0049] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any changes or modifications made by any person skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. An outer rotor motor with heat dissipation, comprising a stator and a rotor, wherein the rotor comprises a rotor shell with a receiving cavity on the top surface, a magnetic yoke ring is arranged on the inner peripheral wall of the receiving cavity, the stator comprises a stator core wound with a coil and a stator shell closing the opening of the receiving cavity, the stator core is located in the receiving cavity, and is characterized in that: A plurality of blades are circumferentially arranged on the bottom wall of the rotor shell, and a first air vent is formed between adjacent blades, which connects the accommodating cavity with the outside world. The stator shell is provided with an annular convex eave extending downward, and the convex eave partially overlaps with the projection of the side wall of the accommodating cavity on the symmetry plane. The convex eave is provided with a plurality of second air vents, which connect the accommodating cavity with the outside world.

2. An outer rotor motor with heat dissipation as claimed in claim 1, characterized in that: The convex eaves surround the outer side of the side wall of the accommodating cavity.

3. An outer rotor motor with heat dissipation as claimed in claim 1, characterized in that: The projections of the second vent hole and the side wall of the accommodating cavity on the symmetry plane do not overlap.

4. An outer rotor motor with heat dissipation as claimed in claim 1, characterized in that: The stator core includes a fixing portion and a winding portion, the fixing portion is fixed to the stator case, the coil is wound on the winding portion, and the winding portion is located directly above the blade.

5. The outer rotor motor with heat dissipation as claimed in claim 1, characterized in that: The included angle between the blades and the horizontal plane is an acute angle, and the projections of adjacent blades on the horizontal plane partially overlap.

6. The outer rotor motor with heat dissipation as claimed in claim 1, characterized in that: The magnetic yoke ring is provided with a positioning portion protruding outward in the radial direction, and the inner side wall of the accommodating cavity is provided with a positioning groove matched with the positioning portion.

7. The outer rotor motor with heat dissipation as claimed in claim 1, characterized in that: The outer rotor motor with heat dissipation also includes a motor shaft, a fixing hole is opened at the center of the bottom of the accommodating cavity, a rotating hole is provided at the center of the stator shell, the bottom end of the motor shaft is fixed in the fixing hole, the top end of the motor shaft passes through the rotating hole, and the motor shaft is rotatably connected to the rotating hole.

8. An outer rotor motor with heat dissipation as claimed in claim 7, characterized in that: The middle of the rotary hole is provided with an abutment portion protruding toward the center direction, and bearings are provided in the rotary hole above and below the abutment portion. The end surface of the bearing abuts against the abutment portion, and the motor shaft passes through the bearing.

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