Outer rotor brushless motor with external bearing
By adopting external bearing design in external rotor motors, combined with the combined structure of built-in and external bearings, the motor height limitation and stability problems are solved, and the entire machine height reduction and stability improvement are achieved, meeting the wider application needs .
Patent Information
- Application Number
- CN202420190665.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-25
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-01-25
AI Technical Summary
The existing external rotor motors have limited motor height due to the built-in bearing structure, which cannot meet the needs of some application scenarios. The built-in single bearing solution may cause the motor external rotor to shake, affecting the smooth operation of the operation.
The bearing external external rotor brushless motor is designed. Through the combined structure of built-in bearing, bracket and external bearing, the installation space with limited height is used to reduce the height of the entire machine, and through interference fit, wave spring and limit groove, etc. The design ensures assembly stability and convenience.
The height of the whole machine is reduced, the stability of the outer rotor is ensured, the swaying is avoided, the bearing assembly process is simplified, and the bearing is prevented from falling off through the limit structure, meeting the needs of a wider range of application scenarios.
Smart Images
Figure CN222356067U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of brushless motors, and in particular relates to a brushless motor with an external bearing and an outer rotor. Background Art
[0002] The brushless motor is composed of the motor body and the driver, and is a typical mechatronics product. Since the brushless DC motor is operated in an automatic manner, it does not require an additional starting winding on the rotor like a synchronous motor that starts under heavy load under variable frequency speed regulation, nor does it produce oscillation and loss of step when the load changes suddenly.
[0003] With the continuous expansion of the application of outer rotor brushless motors in smart home and automotive fields, the integration of products is getting higher and higher, and the market is increasingly pursuing miniaturization and flattening of motor size. Under the premise of meeting performance requirements, the existing outer rotor motor structure can no longer meet the needs of some application scenarios.
[0004] Existing external rotor motors mostly use built-in single bearing, built-in double bearing or built-in multiple bearing solutions. Such solutions have the following problems:
[0005] 1. Built-in single bearing solution: The single-bearing structure outer rotor motor may cause the outer rotor of the motor to shake due to the small contact area between the motor shaft and the bearing, affecting the smooth operation of the motor;
[0006] 2. Built-in dual-bearing or multi-bearing solution: The height of the outer rotor motor is limited by the number of bearings in the mounting bracket and the vertical arrangement of the bearings. The height of the motor cannot be further compressed, resulting in the inability to meet the usage requirements of some scenarios. Utility Model Content
[0007] The utility model aims to provide a brushless motor with an external bearing and an outer rotor, so as to solve the problems mentioned in the above background technology. The utility model provides a brushless motor with an external bearing and an outer rotor, which has the characteristics of making full use of the installation space within a limited height and reducing the height of the whole machine.
[0008] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a bearing-external outer rotor brushless motor, comprising a rotor assembly and a stator assembly, wherein the rotor assembly comprises a casing, a magnetic steel is connected to the inner wall of the casing, a shaft is connected to the center position of the casing, the stator assembly comprises a bracket, a stator core is connected to the inner wall of the bracket, a coil winding is arranged on the stator core, the shaft and the bracket are connected by a built-in bearing, and the bracket and the casing are connected by an external bearing.
[0009] In order to ensure the stability of the assembly between the shaft and the housing, the shaft and the housing are further connected by an interference fit.
[0010] In order to facilitate the assembly of the built-in bearing, further, the inner ring of the built-in bearing is in contact with the shaft, and the outer ring of the built-in bearing is in contact with the bracket.
[0011] In order to facilitate the assembly of the external bearing, further, the inner ring of the external bearing is in contact with the housing, and the outer ring of the external bearing is in contact with the bracket.
[0012] In order to adjust the axial clearance, a wave spring is further provided between the built-in bearing and the bracket.
[0013] In order to limit the position of the built-in bearing and prevent the built-in bearing from falling off, a retaining ring groove is further provided on the circumference of the upper end of the shaft. A shaft retaining ring is embedded in the retaining ring groove.
[0014] In order to limit the external bearing and prevent it from falling off, a step groove corresponding to the external bearing is further provided on the circumference of the housing.
[0015] Compared with the prior art, the beneficial effects of the utility model are:
[0016] 1. The utility model retains the characteristics of the double-bearing structure, ensures the stability of the outer rotor, avoids the disadvantage of the outer rotor shaking, adopts an inner and outer installation method, fully utilizes the installation space within a limited height, and reduces the height of the whole machine;
[0017] 2. The inner ring of the built-in bearing of the utility model contacts the shaft, the outer ring of the built-in bearing contacts the bracket, the inner ring of the external bearing contacts the housing, and the outer ring of the external bearing contacts the bracket, making the assembly of the built-in bearing and the external bearing more convenient;
[0018] 3. A wave spring is provided between the built-in bearing and the bracket of the utility model to adjust the axial clearance;
[0019] 4. The utility model limits the built-in bearing through the shaft retaining ring to prevent the built-in bearing from falling off, and limits the external bearing through the step groove to prevent the external bearing from falling off, making the entire assembly simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic diagram of the explosion of the structure of the utility model;
[0021] Figure 2 It is a cross-sectional structural schematic diagram of the stator assembly of the utility model;
[0022] Figure 3 It is a cross-sectional structural schematic diagram of the rotor assembly of the utility model;
[0023] Figure 4 It is a cross-sectional structural schematic diagram of the utility model;
[0024] In the figure: 1. retaining ring for shaft; 2. wave spring; 3. external bearing; 4. rotor assembly; 41. housing; 42. magnet; 43. shaft; 44. retaining ring groove; 45. step groove; 5. stator assembly; 51. bracket; 52. stator core; 53. coil winding; 6. built-in bearing. DETAILED DESCRIPTION
[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0026] Example 1
[0027] See also Figure 1-4 The utility model provides the following technical solutions: a bearing-external outer rotor brushless motor, comprising a rotor assembly 4 and a stator assembly 5, wherein the rotor assembly 4 comprises a casing 41, a magnetic steel 42 is connected to the inner wall of the casing 41, a shaft 43 is connected to the center of the casing 41, the stator assembly 5 comprises a bracket 51, a stator core 52 is connected to the inner wall of the bracket 51, a coil winding 53 is provided on the stator core 52, the shaft 43 and the bracket 51 are connected via a built-in bearing 6, and the bracket 51 and the casing 41 are connected via an external bearing 3.
[0028] By adopting the above technical solution, the utility model retains the characteristics of the double-bearing structure, ensures the stability of the outer rotor, avoids the disadvantage of outer rotor shaking, adopts an inside-one-outside installation method, fully utilizes the installation space within a limited height, and realizes a reduction in the height of the entire machine.
[0029] Specifically, the shaft 43 and the housing 41 are connected by interference fit.
[0030] By adopting the above technical solution, the stability of the assembly between the shaft 43 and the housing 41 is ensured.
[0031] Specifically, the inner ring of the built-in bearing 6 contacts the shaft 43 , and the outer ring of the built-in bearing 6 contacts the bracket 51 .
[0032] By adopting the above technical solution, the assembly of the built-in bearing 6 is facilitated.
[0033] Specifically, the inner ring of the external bearing 3 contacts the housing 41 , and the outer ring of the external bearing 3 contacts the bracket 51 .
[0034] By adopting the above technical solution, the assembly of the external bearing 3 is facilitated.
[0035] Example 2
[0036] The present embodiment is different from the first embodiment in that, specifically, a wave spring 2 is provided between the built-in bearing 6 and the bracket 51 .
[0037] The above technical solution is used to adjust the axial clearance.
[0038] Due to the machining accuracy of parts (affecting the position of the retaining ring groove 44 and the height of the step inside the casing 41) and assembly reasons (the shaft 43 and the casing 41 affect the height of the step inside the retaining ring groove 44 relative to the casing 41 after they are matched), the height of the step inside the casing 41 relative to the retaining ring groove 44 is the bearing installation dimension H. If no dimensional margin is left for the wave spring to adjust the clearance, when installing the bearing, if H is greater than the bearing height, the bearing will move up and down, and if H is less than the bearing height, the bearing cannot be installed.
[0039] Example 3
[0040] The present embodiment is different from the first embodiment in that: specifically, a retaining ring groove 44 is provided on the circumference of the upper end of the shaft 43. A shaft retaining ring 1 is embedded in the retaining ring groove 44.
[0041] By adopting the above technical solution, the built-in bearing 6 is limited to prevent the built-in bearing 6 from falling off.
[0042] Specifically, a step groove 45 corresponding to the external bearing 3 is provided on the circumference of the housing 41 .
[0043] By adopting the above technical solution, the external bearing 3 is limited to prevent the external bearing 3 from falling off.
[0044] Furthermore, the utility model provides a brushless motor with an external bearing and an outer rotor, comprising the following steps:
[0045] (i) The bracket 51, the stator core 52 and the coil winding 53 constitute the stator assembly 5;
[0046] (ii) the housing 41, the magnet 42 and the shaft 43 form a rotor assembly 4;
[0047] (III) Assemble the external bearing 3 into the step groove 45, and then install the stator assembly 5;
[0048] (IV) Install the wave spring 2 into the bracket 51, then install the built-in bearing 6, and finally install the shaft retaining ring 1 into the retaining ring groove 44.
[0049] In summary, the utility model retains the characteristics of the double-bearing structure, ensures the stability of the outer rotor, avoids the disadvantage of the outer rotor shaking, adopts an inner and outer installation method, fully utilizes the installation space within the limited height, and realizes the reduction of the height of the whole machine; the inner ring of the built-in bearing 6 of the utility model contacts the shaft 43, the outer ring of the built-in bearing 6 contacts the bracket 51, the inner ring of the external bearing 3 contacts the casing 41, and the outer ring of the external bearing 3 contacts the bracket 51, so that the assembly of the built-in bearing 6 and the external bearing 3 is more convenient; a wave spring 2 is provided between the built-in bearing 6 and the bracket 51 of the utility model for adjusting the axial clearance; the utility model limits the built-in bearing 6 by a shaft retaining ring 1 to prevent the built-in bearing 6 from falling off, and limits the external bearing 3 by a step groove 45 to prevent the external bearing 3 from falling off, so that the entire assembly is simple and convenient.
[0050] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A brushless motor with an external bearing and an outer rotor, characterized in that: It includes a rotor assembly and a stator assembly, wherein the rotor assembly includes a casing, a magnet is connected to the inner wall of the casing, a shaft is connected to the center of the casing, the stator assembly includes a bracket, a stator core is connected to the inner wall of the bracket, a coil winding is arranged on the stator core, the shaft and the bracket are connected by an internal bearing, and the bracket and the casing are connected by an external bearing.
2. The outer rotor brushless motor with external bearing according to claim 1, characterized in that: The shaft and the housing are connected through interference fit.
3. The outer rotor brushless motor with external bearing according to claim 1, characterized in that: The inner ring of the built-in bearing contacts the shaft, and the outer ring of the built-in bearing contacts the bracket.
4. The outer rotor brushless motor with external bearing according to claim 1, characterized in that: The inner ring of the external bearing contacts the housing, and the outer ring of the external bearing contacts the bracket.
5. The outer rotor brushless motor with external bearing according to claim 1, characterized in that: A wave spring is arranged between the built-in bearing and the bracket.
6. The outer rotor brushless motor with external bearing according to claim 1, characterized in that: A retaining ring groove is arranged on the circumference of the upper end of the shaft.
7. The outer rotor brushless motor with external bearing according to claim 6, characterized in that: A shaft retaining ring is embedded in the retaining ring groove.
8. The outer rotor brushless motor with external bearing according to claim 1, characterized in that: A step groove corresponding to the external bearing is arranged on the circumference of the housing.