Outer rotor motor structure

Abstract

An external rotor motor structure comprises a motor shell (1), a stator assembly (2), a rotor assembly (3) and a main shaft (4). The motor is characterized in that the main shaft (4) is arranged in the motor shell (1) in a penetrating manner, so that the main shaft (4) is supported by bearings (5) at two ends; a tubular support (13) is arranged on an end cover (121) of the tail end (12) of the motor shell (1) and extends towards the interior of the motor shell, the stator assembly (2) is fixedly arranged on the tubular support (13) in a sleeved mode, and a rotor support (6) is fixedly arranged on the main shaft (4) in a sleeved mode. Fan blades (61) are arranged on the rotor support (6) to form a fan structure, a ventilation opening (14) is formed in the position, corresponding to the periphery of the fan structure, of the motor shell (1), a plurality of ventilation grooves (15) are formed in the tail end of the motor shell (1) or an end cover of the motor shell (1), and a heat dissipation channel in the motor is formed through the ventilation grooves (15), gaps in the motor, the fan structure and the ventilation opening (14).

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to an outer rotor motor structure. Background Art

[0002] As a power source, electric motors are widely used in many fields, including medical machinery and power tools. Generally, electric motors drive output components or transmission components by outputting torque.

[0003] Motors can be categorized into two main categories: inner rotor motors and outer rotor motors. Outer rotor motors offer high torque, low noise, and high speed. They can have a larger number of magnetic poles, resulting in a smaller pole switching angle and lower overall vibration during operation. Consequently, outer rotor motors are increasingly being used. Currently, there are a number of small motors with an outer diameter of less than 40mm, low noise, and high power density. However, these motors present challenges such as complex assembly, high cost, and heat dissipation difficulties, which urgently require technical expertise to address. Utility Model Content

[0004] The utility model aims to provide an outer rotor motor structure which is easy to assemble.

[0005] In order to achieve the above-mentioned purpose, the first technical solution adopted by the present invention is: an outer rotor motor structure, comprising a motor housing, a stator assembly arranged in the motor housing and fixed relative to the motor housing, a rotor assembly arranged between the stator assembly and the inner wall of the motor housing, and a main shaft transmission-connected to the rotor assembly; of the two ends of the motor housing, one end serves as a power output end, and the other end serves as a tail end, and the power output end and the tail end are respectively provided with an end cover, wherein at least one end cover is a split cover placed at the corresponding end; the main shaft is passed through the motor housing, and bearings are provided on the end cover corresponding to the main shaft openings, so as to support the main shaft through the bearings at both ends. Main shaft; a tubular bracket is provided on the tail end cover of the motor housing and extends into the motor housing, and the stator assembly is fixed on the tubular bracket, and a rotor bracket is fixedly provided on the main shaft on the side close to the power output end, and the outer edge of the rotor bracket is fixedly connected to the rotor assembly; fan blades are provided on the rotor bracket to form a fan structure, and ventilation holes are provided on the motor housing corresponding to the periphery of the fan structure, and a plurality of ventilation slots are provided on the tail end of the motor housing or its end cover around the circumference of the main shaft, and a heat dissipation path inside the motor is formed through the ventilation slots, the internal gap of the motor, the fan structure and the ventilation holes.

[0006] In the above solution, the ventilation direction of the heat dissipation path is to enter from the ventilation slot and flow out from the ventilation port.

[0007] In the above scheme, a reducer housing is also provided on the power output end of the motor housing, which is fixedly connected to the motor housing. A planetary gear reduction mechanism is provided in the reducer housing, which is connected to the main shaft transmission to reduce the power output of the motor main shaft.

[0008] Furthermore, the motor housing and the reducer housing are snap-fitted with the ends having non-circular cross-sections and are fixedly connected with fasteners or glued.

[0009] In the above solution, the rotor bracket is integrally formed of an aluminum-cast bracket body, a plastic-coated blade body, and an insert. The insert is interference-fitted around the outer circumference of the main shaft, the aluminum-cast bracket body is integrally mounted on the outer circumference of the insert, and the aluminum-cast bracket body is fixedly connected to the rotor assembly, while the plastic-coated blade body is located on the end of the bracket body facing the outside of the motor housing. In practice, the aluminum-cast bracket body is not limited to aluminum castings and can also be a drawn, stamped, or machined part; the blade body is not limited to plastic-coated and can also be assembled or integrated with the bracket body; and the insert can also be integrally connected to the bracket body as a single component.

[0010] In order to achieve the above-mentioned purpose, the first technical solution adopted by the present invention is: an outer rotor motor structure, comprising a motor housing, a stator assembly arranged in the motor housing and fixed relative to the motor housing, a rotor assembly arranged between the stator assembly and the inner wall of the motor housing, and a main shaft transmission-connected to the rotor assembly; of the two ends of the motor housing, one end serves as a power output end, and the other end serves as a tail end, and the power output end and the tail end are respectively provided with an end cover, wherein at least one end cover is a split cover and is placed at the corresponding end; the main shaft is placed in the motor housing, and bearings are provided on the end cover corresponding to the main shaft openings to support the main shaft through the bearings at both ends; the end cover of the power output end of the motor housing is provided with a bearing. A tubular bracket is provided extending into the motor housing and is arranged on the periphery of the main shaft. The stator assembly is sleeved and fixed on the tubular bracket, and a rotor bracket is fixedly sleeved on the main shaft near the tail end, and the outer edge of the rotor bracket is fixedly connected to the rotor assembly; fan blades are provided on the rotor bracket to form a fan structure, and a ventilation opening is provided on the motor housing or its end cover corresponding to the fan structure; a ventilation gap is left between the stator assembly and the end cover of the power output end; and a ventilation groove is provided on the motor housing corresponding to the ventilation gap between the stator assembly and the end cover of the power output end, and a heat dissipation path inside the motor is formed through the ventilation groove, the internal gap of the motor, the fan structure and the ventilation opening.

[0011] In the above solution, the ventilation direction of the heat dissipation path is to enter from the ventilation slot and flow out from the ventilation port.

[0012] In the above scheme, a reducer housing is also provided on the power output end of the motor housing, which is fixedly connected to the motor housing. A planetary gear reduction mechanism is provided in the reducer housing, which is connected to the main shaft transmission to reduce the power output of the motor main shaft.

[0013] In the above solution, the motor housing and the reducer housing are snap-fitted at the ends with non-circular cross-sections and fixedly connected by fasteners or glued.

[0014] In the above solution, the rotor bracket is integrally formed of an aluminum-cast bracket body, a plastic-coated blade body, and an insert. The insert is interference-fitted around the outer circumference of the main shaft, the aluminum-cast bracket body is integrally mounted on the outer circumference of the insert, and the aluminum-cast bracket body is fixedly connected to the rotor assembly, while the plastic-coated blade body is located on the end of the bracket body facing the outside of the motor housing. In practice, the aluminum-cast bracket body is not limited to aluminum castings and can also be a drawn, stamped, or machined part; the blade body is not limited to plastic-coated and can also be assembled or integrated with the bracket body; and the insert can also be integrally connected to the bracket body as a single component.

[0015] The utility model has the following advantages: it is easy to assemble, has low production cost, and the fan structure designed on the rotor bracket forms an effective heat dissipation path inside the motor, which has a good heat dissipation effect. The utility model is particularly suitable for making micro motors with an outer diameter of 40mm, and has good heat dissipation, low cost and easy assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall exterior of the first embodiment of the present invention. Figure 1 ;

[0017] Figure 2 This is a cross-sectional view of the joint between the motor housing and the reducer housing of the first embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of a fully cutaway perspective view of a first embodiment of the present invention;

[0019] Figure 4 This is a structural diagram of a motor housing and a reducer housing according to a first embodiment of the present invention;

[0020] Figure 5 This is a schematic structural diagram of the motor structure of Example 1 of the utility model after removing the motor housing and the main shaft;

[0021] Figure 6 Schematic diagram of a planetary gear reduction mechanism according to the first embodiment of the present invention Figure 1 ,This figure shows the power input end of the planetary gear reduction mechanism facing forward;

[0022] Figure 7Schematic diagram of a planetary gear reduction mechanism according to the first embodiment of the present invention Figure 2 ,This figure shows the power output end of the planetary gear reduction mechanism facing forward;

[0023] Figure 8 This is a schematic diagram of a fully cutaway perspective view of the second embodiment of the present invention.

[0024] In the above figures: 1, motor housing; 11, power output end; 12, tail end; 111 (121), end cover; 13, tubular bracket; 14, vent; 15, ventilation slot;

[0025] 2. Stator assembly;

[0026] 3. Rotor assembly;

[0027] 4. Spindle;

[0028] 5. Bearings;

[0029] 6. Rotor bracket; 61. Fan blade; 62. Aluminum cast bracket body; 63. Plastic coated fan blade body; 64. Insert;

[0030] 7. Reducer housing;

[0031] 8. Planetary gear reduction mechanism;

[0032] 9. Ventilation gap. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] Example 1, an outer rotor motor structure, see Figure 1-Figure 7 As shown:

[0035] An outer rotor motor structure includes a motor housing 1, a stator assembly 2 arranged in the motor housing 1 and fixed relative to the motor housing 1, a rotor assembly 3 arranged between the stator assembly 2 and the inner wall of the motor housing 1, and a main shaft 4 transmission-connected to the rotor assembly 3.

[0036] See also Figures 1-4 As shown, one end of the motor housing 1 is used as the power output end 11 and the other end is used as the tail end 12. The power output end 11 and the tail end 12 are each provided with an end cover, wherein at least one end cover is a split cover placed on the corresponding end, as shown in FIG. Figure 3 In the example, the end cover 111 of the power output end 11 is fixedly assembled with the motor housing 1 as a separate body, while the end cover 121 of the tail end 12 is connected with the motor housing 1 as an integral body.

[0037] The main shaft 4 is inserted into the motor housing 1 , and bearings 5 ​​are provided on the end cover corresponding to the openings of the main shaft 4 so as to support the main shaft 4 through the bearings 5 ​​at both ends.

[0038] See also Figures 1-4 As shown, a tubular bracket 13 is provided on the end cover 121 of the tail end 12 of the motor housing 1 and extends into the motor housing. The stator assembly 2 is sleeved and fixed on the tubular bracket 13, and a rotor bracket 6 is fixedly sleeved on the main shaft 4 on the side close to the power output end 11. The outer edge of the rotor bracket 6 is fixedly connected to the rotor assembly 3.

[0039] The stator assembly 2 is composed of a stator core, stator windings, and a plastic cover. The plastic cover can be fixed to the stator core in an assembled or plastic-coated manner. Depending on different needs, the stator assembly can be provided with insulating paper, a PCB board, and conductive terminals.

[0040] The stator assembly 2 is preferably fitted onto the tubular support 13 by interference fit, and the tubular support 13 may be provided with positioning features such as grooves.

[0041] The rotor assembly 3 mainly includes a permanent magnet and a positioning frame. The permanent magnet is embedded in the end of the rotor support 6 for positioning connection.

[0042] See also Figures 1-4 As shown, in particular, the rotor bracket 6 is provided with blades 61 to form a fan structure, a vent 14 is provided on the motor housing 1 corresponding to the periphery of the fan structure, and a plurality of ventilation slots 15 are provided on the tail end of the motor housing 1 or its end cover around the circumference of the main shaft 4, and a heat dissipation path inside the motor is formed through the ventilation slots 15, the internal gap of the motor, the fan structure and the vent 14. Specifically, Figure 3 and Figure 4 As shown, the ventilation slot 15 is opened on the end cover 121 of the tail end 12 of the motor housing 1 .

[0043] This structure has a better heat dissipation effect, and the ventilation direction of the heat dissipation path is to enter from the ventilation slot 15 and flow out from the ventilation port 14. In practice, the reverse setting is also feasible.

[0044] See also Figures 1-4 As shown, a reducer housing 7 is also provided on the power output end 11 of the motor housing 1. The reducer housing 7 is fixedly connected to the motor housing 1. A planetary gear reduction mechanism 8 is provided in the reducer housing 7. The planetary gear reduction mechanism 8 is transmission-connected to the main shaft 4 to reduce the power output of the motor main shaft 4.

[0045] See Figure 6 and Figure 7 As shown in the figure, the planetary gear reduction mechanism 9 is composed of multiple sets of planetary gears, specifically a three-stage planetary gear set as shown in the figure.

[0046] See also Figure 2As shown, the motor housing 1 and reducer housing 7 are connected at their non-circular cross-section ends, secured with fasteners or glue. This non-circular cross-section is designed to facilitate assembly and prevent errors, allowing them to be locked into place during assembly. When radial space is sufficient, fasteners can be used for axial or radial positioning. Specifically, the fasteners can be screws or pins.

[0047] The rotor bracket 6 is composed of an aluminum casting bracket body 62, a plastic-coated fan blade body 63 and an insert 64. The insert 64 is interference-fitted on the outer periphery of the main shaft 4. The insert 64 can be made of powder metallurgy or iron alloy machining.

[0048] like Figure 2 and Figure 5 As shown, the aluminum casting bracket body 62 is provided on the outer periphery of the insert 64. It can be die-cast integrally with the insert 64 or press-fitted onto the insert 64. The aluminum casting bracket body 62 is fixedly connected to the rotor assembly 3, and the plastic-coated fan blade body 63 is located on the end of the bracket body facing the outside of the motor housing 1.

[0049] In practice, the aluminum casting bracket body 62 is not limited to aluminum castings, but can also be stretched, stamped, or machined parts; the fan blade body 63 is not limited to plastic coating, but can also be assembled or integrated with the bracket body 62; the insert 64 can also be connected to the bracket body 62 as one part.

[0050] Specifically, the motor housing 1 and the reducer housing 7 are fixedly connected by fasteners, which may be pins, screws, etc. Alternatively, the motor housing 1 and the reducer housing 7 are fixedly connected by gluing. In practice, the motor housing 1 and the reducer housing 7 may also be connected by threaded engagement, or even directly manufactured as a single piece.

[0051] Example 2, an outer rotor motor structure, see Figure 8 As shown:

[0052] An outer rotor motor structure, which differs from the first embodiment in that: the tubular bracket 13 is formed by protruding from the end cover 111 of the power output end 11 of the motor housing 1, and the end cover 121 of the tail end 12 of the motor housing 1 is fixedly connected to the motor housing 1 in a separate assembled manner, and the rotor bracket 6 is fixedly sleeved on the tail end 12 side of the main shaft 4, that is, the fan structure is located on the tail end 12 side of the motor, and a ventilation gap 9 is left between the stator assembly 2 and the end cover 111 of the power output end 11; and a ventilation slot 15 is also provided on the motor housing 1 corresponding to the ventilation gap 9 between the stator assembly 2 and the end cover 111 of the power output end 11, and a heat dissipation path inside the motor is formed through the ventilation slot 15, the internal gap of the motor, the fan structure to the vent 14.

[0053] The rest is the same as in the first embodiment and will not be described again here.

[0054] The embodiments described are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those familiar with the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications based on the spirit of the present invention shall be included in the scope of protection of the present invention.

Claims

1. An outer rotor motor structure, comprising a motor housing (1), a stator assembly (2) disposed within the motor housing (1) and fixed relative to the motor housing (1), a rotor assembly (3) disposed between the stator assembly (2) and an inner wall of the motor housing (1), and a main shaft (4) drivingly connected to the rotor assembly (3); characterized in that: Of the two ends of the motor housing (1), one end serves as a power output end (11) and the other end serves as a tail end (12), and end covers are respectively provided on the power output end (11) and the tail end (12), wherein at least one end cover is a split cover and is placed on the corresponding end; the main shaft (4) is inserted into the motor housing (1), and bearings (5) are provided on the end covers corresponding to the openings of the main shaft (4), so as to support the main shaft (4) through the bearings (5) at both ends; A tubular bracket (13) is provided on the end cover (121) of the tail end (12) of the motor housing (1) and extends into the motor housing. The stator assembly (2) is sleeved and fixed on the tubular bracket (13). A rotor bracket (6) is fixedly sleeved on the main shaft (4) on the side close to the power output end (11). The outer edge of the rotor bracket (6) is fixedly connected to the rotor assembly (3). The rotor bracket (6) is provided with fan blades (61) to form a fan structure, a ventilation opening (14) is provided on the motor housing (1) corresponding to the periphery of the fan structure, and a plurality of ventilation slots (15) are provided on the tail end of the motor housing (1) or its end cover in the circumferential direction around the main shaft (4), and a heat dissipation path inside the motor is formed through the ventilation slots (15), the internal gap of the motor, the fan structure and the ventilation opening (14).

2. The outer rotor motor structure according to claim 1, characterized in that: The ventilation direction of the heat dissipation passage is to enter from the ventilation slot (15) and flow out from the ventilation port (14).

3. The outer rotor motor structure according to claim 1, characterized in that: A reducer housing (7) is also provided on the power output end (11) of the motor housing (1). The reducer housing (7) is fixedly connected to the motor housing (1). A planetary gear reduction mechanism (8) is provided in the reducer housing (7). The planetary gear reduction mechanism (8) is transmission-connected to the main shaft (4) to reduce the power output of the motor main shaft (4).

4. The outer rotor motor structure according to claim 3, characterized in that: The motor housing (1) and the reducer housing (7) are clamped together at the ends of the non-circular cross-sections and fixedly connected by fasteners or glued together.

5. The outer rotor motor structure according to claim 1, characterized in that: The rotor bracket (6) is integrally formed of an aluminum casting bracket body (62), a plastic-coated fan blade body (63), and an insert (64); the insert (64) is interference-fitted on the outer periphery of the main shaft (4); the aluminum casting bracket body (62) is integrally arranged on the outer periphery of the insert (64); the aluminum casting bracket body (62) is fixedly connected to the rotor assembly (3), and the plastic-coated fan blade body (63) is located on an end of the bracket body facing the outside of the motor housing (1).

6. An outer rotor motor structure, comprising a motor housing (1), a stator assembly (2) disposed within the motor housing (1) and fixed relative to the motor housing (1), a rotor assembly (3) disposed between the stator assembly (2) and an inner wall of the motor housing (1), and a main shaft (4) drivingly connected to the rotor assembly (3); characterized in that: Of the two ends of the motor housing (1), one end serves as a power output end (11) and the other end serves as a tail end (12), and end covers are respectively provided on the power output end (11) and the tail end (12), wherein at least one end cover is a split cover and is placed on the corresponding end; the main shaft (4) is inserted into the motor housing (1), and bearings (5) are provided on the end covers corresponding to the openings of the main shaft (4), so as to support the main shaft (4) through the bearings (5) at both ends; A tubular bracket (13) is provided on the end cover of the power output end (11) of the motor housing (1) and extends into the motor housing (1). The stator assembly (2) is sleeved and fixed on the tubular bracket (13). A rotor bracket (6) is fixedly sleeved on the main shaft (4) near the tail end (12). The outer edge of the rotor bracket (6) is fixedly connected to the rotor assembly (3). The rotor bracket (6) is provided with fan blades (61) to form a fan structure, and a ventilation opening (14) is provided on the motor housing (1) or its end cover corresponding to the fan structure; a ventilation gap (9) is left between the stator assembly (2) and the end cover (111) of the power output end (11); and a ventilation slot (15) is provided on the motor housing (1) corresponding to the ventilation gap (9) between the stator assembly (2) and the end cover (111) of the power output end (11), and a heat dissipation path inside the motor is formed through the ventilation slot (15), the internal gap of the motor, the fan structure and the ventilation opening (14).

7. The outer rotor motor structure according to claim 6, characterized in that: The ventilation direction of the heat dissipation passage is to enter from the ventilation slot (15) and flow out from the ventilation port (14).

8. The outer rotor motor structure according to claim 6, characterized in that: A reducer housing (7) is also provided on the power output end (11) of the motor housing (1). The reducer housing (7) is fixedly connected to the motor housing (1). A planetary gear reduction mechanism (8) is provided in the reducer housing (7). The planetary gear reduction mechanism (8) is transmission-connected to the main shaft (4) to reduce the power output of the motor main shaft (4).

9. The outer rotor motor structure according to claim 8, characterized in that: The motor housing (1) and the reducer housing (7) are clamped together at the ends of the non-circular cross-sections and fixedly connected by fasteners or glued together.

10. The outer rotor motor structure according to claim 6, characterized in that: The rotor bracket (6) is integrally formed of an aluminum casting bracket body (62), a plastic-coated fan blade body (63), and an insert (64); the insert (64) is interference-fitted on the outer periphery of the main shaft (4); the aluminum casting bracket body (62) is integrally arranged on the outer periphery of the insert (64); the aluminum casting bracket body (62) is fixedly connected to the rotor assembly (3), and the plastic-coated fan blade body (63) is located on an end of the bracket body facing the outside of the motor housing (1).

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