Brushless motor for gardening tool
By using insulated fixing frames and limiting columns in brushless motors of garden tools, the problem of the traditional brushless motor leads being in contact with the lower bracket is solved, achieving higher safety and lower production costs.
Patent Information
- Application Number
- CN202421305847.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-06-07
AI Technical Summary
In garden tools, the traditional brushless outer rotor motor has not been fixed in wire leads of the stator winding, causing the lead position to move downward in the axial direction during the grassing process, causing the lead to contact with the lower bracket, causing the live phenomenon, affecting the safety of the motor and the safety of the operator.
A fixture made of insulating material is concave in the axial direction and crosses the leads to isolate the leads and lower brackets to avoid current conduction. At the same time, by setting limiting columns and wire ducts, ensure the insulation isolation of the leads from the lower bracket and avoid damage to the enameled wire.
It effectively avoids the current on the lead wire to the lower bracket, prevents the cutter head from being charged, improves the safety of the motor and the safety of the operator, and reduces production costs and avoids damage to the enameled wire.
Smart Images
Figure CN222928177U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of gardening tools, and particularly relates to a brushless motor for gardening tools. Background Art
[0002] Most gardening tools adopt a handheld structure, and their requirements for safety performance are more stringent to prevent the tool from being electrified, and there is a risk of electric shock for the user during the operation process. Brushless motors are frequently used in gardening tools. For traditional brushless outer rotor motors, the wire lead-out position of the stator winding is only wrapped with enameled wire and is not fixed. During the grass trimming process, vibrations will occur, and the lead position will move downward along the axis. Since the safety distance between the lead and the lower bracket is short, the lead will contact the lower bracket, resulting in an electrified phenomenon. The electrification will be transmitted to the cutter head, which affects both the safety of the motor itself and the safety of the operator.
[0003] In view of the above disadvantages, the current solutions are: on the one hand, increasing the above-mentioned safety distance by increasing the axial length of the motor, and on the other hand, adding a pressing and shaping process to the wire lead-out position in the process. However, such operations not only increase the production cost, but also the pressing process may damage the enameled wire, resulting in a low qualified rate of the finished product. Summary of the Utility Model
[0004] In view of the deficiencies of the prior art, the utility model provides a brushless motor for gardening tools, which can avoid the drawback that the current on the lead conducts to the lower bracket, resulting in the cutter head being electrified, and has low production cost and avoids the occurrence of enameled wire breakage.
[0005] The utility model is realized through the following technical solutions:
[0006] A brushless motor for gardening tools, the gardening tool includes a lower bracket, the brushless motor includes a stator assembly, the stator assembly includes a stator winding, the brushless motor further includes a fixing frame, the fixing frame has opposite first and second surfaces along the axis, the stator winding is located on one side of the first surface, the lower bracket is located on one side of the second surface, and the lead on the stator winding passes through the gap between the stator winding and the first surface;
[0007] Wherein, the fixing frame is made of insulating material;
[0008] The fixing frame is recessed axially and passes over the lead, so that the lead and the lower bracket are relatively isolated, avoiding the current on the lead from conducting to the lower bracket.
[0009] Furthermore, multiple lead wires are externally connected to wires, and the connection between each lead wire and the wire is wrapped with enameled wire. A limiting column is protruding from the fixing frame, and the limiting column is used to isolate the enameled wires on the outside of different lead wires from each other.
[0010] Furthermore, multiple lead wires are externally connected to wires, and the connection between each lead wire and the wire is wrapped with enameled wire. A limiting column is protruding from the fixing frame, and the limiting column is used to isolate the enameled wires on the outside of different lead wires from each other.
[0011] Furthermore, a plurality of wire grooves are provided on the extended portion of the fixing frame, and the plurality of wires are housed in the plurality of wire grooves in a one-to-one correspondence.
[0012] Furthermore, a limit plate is provided above the wire trough to prevent the wire from escaping from the wire trough, and both ends of the limit plate are fixedly connected to the lower bracket by screws.
[0013] Furthermore, columns are provided on the lower bracket at positions corresponding to the screws, threaded holes matched with the screws are provided on the columns, and the columns can limit the extension portion.
[0014] Furthermore, the stator assembly also includes a stator core, and the stator core is sleeved on the extension portion of the lower bracket.
[0015] Furthermore, the stator assembly also includes a stator bracket, and the stator bracket includes a first bracket, the first bracket is sleeved on the extension of the lower bracket, and one side of the first bracket is matched with one side of the stator core, and the other side is abutted against the fixing frame.
[0016] Furthermore, the fixing frame is provided with an avoidance hole for the extension portion of the lower bracket to pass through.
[0017] Furthermore, the end wall forming the avoidance hole abuts against the other side of the first bracket.
[0018] Furthermore, the stator bracket also includes a second bracket, the second bracket is sleeved on the extension of the lower bracket, and the second bracket is matched with the other side of the stator core.
[0019] Furthermore, the brushless motor further comprises a rotor assembly and a rotating shaft, wherein the rotor assembly comprises a rotating shell and a permanent magnet fixed on the rotating shell, and the rotating shell is interference fit with the rotating shaft.
[0020] Furthermore, the lower bracket includes a main body portion and the extension portion integrally formed with the main body portion, the extension portion extends axially and is hollow, and the rotating shaft passes through the extension portion and is coaxially arranged with the extension portion.
[0021] Furthermore, the brushless motor also includes at least one first bearing, a first bearing cavity is formed at one end of the extension portion adjacent to the stator core, and the first bearing sleeve is arranged on the rotating shaft and placed in the first bearing cavity.
[0022] Furthermore, the brushless motor also includes at least one second bearing, a second bearing chamber is formed in the lower bracket, and the second bearing is sleeved on the rotating shaft and placed in the second bearing chamber.
[0023] Furthermore, the second bearing chamber is formed in a partial space of the inner side wall of the convex portion of the main body or on the extended portion.
[0024] Compared with the prior art, the advantages of the present invention are:
[0025] 1. By setting a fixing frame, the fixing frame is made of insulating material and is set between the lower bracket and the stator winding. The multiple leads of the stator winding and the lower bracket are isolated in the space on both sides of the fixing frame in the axial and radial directions to avoid the current on the lead wires from being conducted to the metal lower bracket, thereby avoiding the disadvantage of the current being conducted to the cutter head being electrified. Compared with the existing process, the production cost is low and the damage of the enameled wire is avoided.
[0026] 2. By abutting the first bracket located at the bottom of the stator core with the fixing frame, an isolation wall is formed again between the first bracket and the fixing frame in the axial direction, and the lead wire and the lower bracket are further insulated and isolated in the space on both sides of the isolation wall, further avoiding the risk of current on the lead wire caused by vibration being conducted to the lower bracket.
[0027] 3. By setting up wire troughs, the wires can be completely stored in the trough body, with clear classification and avoid entanglement with each other; and by setting a limit plate above the wire trough, the wires can be prevented from escaping from the wire trough.
[0028] 4. By setting limit columns to separate the two enameled wires, the movement is reduced and the contact between the enameled wires on the outside of different leads is avoided, thereby avoiding relative wear, ensuring the integrity and insulation of the enameled wires and extending their service life. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a structural schematic diagram of a brushless motor;
[0030] Figure 2 It is a partial structural schematic diagram of a brushless motor;
[0031] Figure 3 It is a partial structural schematic diagram of the stator assembly;
[0032] Figure 4 It is a cross-sectional view of a brushless motor;
[0033] Figure 5 Schematic structure of the fixing bracket Figure 1 ;
[0034] Figure 6 Schematic structure of the fixing bracket Figure 2 ;
[0035] Figure 7 Schematic diagram of the structure of the lower bracket.
[0036] 1. Lower bracket; 10. Extension part; 11. Body part; 110. Convex part; 12. Column; 120. Threaded hole; 13. First chamber; 14. Second chamber; 2. Stator assembly; 20. Stator winding; 200. Lead wire; 201. Enameled wire; 202. Insulating part; 21. Stator core; 210. Fitting hole; 22. Stator bracket; 220. First bracket; 221. Second bracket; 222. Fitting post; 23. Wire; 230. Core wire; 231. Epidermis; 3. Fixing bracket; 30. Limit post; 31. Extension part; 310. Wire groove; 32. Avoidance hole; 320. End wall; 33. Limit plate; 34. Screw; 35. Concave part; 36. Inner concave part; 4. Rotor assembly; 40. Rotating shell; 41. Permanent magnet; 5. Rotating shaft; 6. First bearing; 7. Second bearing; 8. Fan; 9. Gear. Detailed implementation manners
[0037] The technical solution of the utility model will be further described in detail and non - restrictively below in conjunction with the preferred embodiments and their accompanying drawings. In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present utility model and should not be construed as a limitation of the present utility model.
[0038] As Figures 1-7As shown in the figure, a brushless motor for a garden tool according to an embodiment of the present invention, the garden tool includes a lower bracket 1. In this embodiment, the brushless motor is a brushless outer rotor motor, which mainly includes a stator assembly 2, a fixing bracket 3, a rotor assembly 4 and a rotating shaft 5. The rotor assembly 4 is arranged outside the stator assembly 2, and the rotating shaft 5 passes through the stator assembly 2 and is in interference fit with the rotor assembly 4. When the stator assembly 2 is powered on, a magnetic field capable of cooperating with the rotor assembly 4 is generated, thereby driving the rotor assembly 4 to rotate and driving the rotating shaft 5 to rotate synchronously. Among them, the stator assembly 2, the rotor assembly 4 and the rotating shaft 5 are coaxially arranged.
[0039] The stator assembly 2 includes a stator winding 20, a stator core 21 and a stator bracket 22. The stator bracket 22 includes a first bracket 220 and a second bracket 221. The stator core 21 is axially located between the first bracket 220 and the second bracket 221, and one side of the first bracket 220 is connected to one side of the stator core 21, and the other side is in contact with the fixing bracket 3. The second bracket 221 is connected to the other side of the stator core 21. Among them, the stator bracket 22 is made of insulating material.
[0040] The fixing bracket 3 has a first surface and a second surface facing away from each other in the axial direction. The stator winding 20 is located on one side of the first surface, and the lower bracket 1 is located on one side of the second surface. The lead 200 on the stator winding 20 passes through the gap between the stator winding 20 and the first surface; the fixing bracket 3 is recessed axially and crosses the lead 200, so that the lead 200 and the lower bracket 1 are relatively isolated, preventing the current on the lead 200 from being conducted to the lower bracket 1.
[0041] Furthermore, the concave portion 36 of the fixing bracket 3 is in contact with the insulating portion 202 of the stator winding 20, so that the lead 200 and the lower bracket 1 are relatively insulated and isolated.
[0042] As Figure 3 shown, the stator core 21 is provided with a mating hole 210, and mating posts 222 are protruded on both the first bracket 220 and the second bracket 221. The mating post 220 is mated with the mating hole 210.
[0043] The fixing bracket 3 is made of insulating material and is arranged between the lower bracket 1 and the stator winding 20. In one way, the other side of the first bracket 220 abuts against the fixing bracket 3, and the abutting part of the two is located inside the multiple leads 200 of the stator winding 20. Thus, the multiple leads 200 and the lower bracket 1 can be completely isolated in the spaces on both sides of the fixing bracket 3, so that the contact between the multiple leads 200 and the lower bracket 1 can be completely avoided. Further, the current on the multiple leads 200 can be completely prevented from being conducted to the lower bracket 1 and then to the tool bit. This application adopts this way. In another way, the fixing bracket 3 is concave inward along the axis and crosses the lead-out part of the multiple leads 200 of the stator winding 20, which can also isolate the multiple leads 200 and the lower bracket 1 in the spaces on both sides of the fixing bracket 3. The vibration generated in the working environment basically will not cause any lead 200 to shake and contact the lower bracket 1, so that the current on the multiple leads 200 can be prevented from being conducted to the lower bracket 1 and then to the tool bit.
[0044] Multiple leads 200 are all externally connected with wire materials 23, and an enameled wire 201 is wrapped around the connection part of each lead 200 and the wire material 23. A limiting post 30 is convexly arranged on the fixing bracket 3, and the limiting post 30 is used to isolate the enameled wires 201 outside different leads 200 from each other. Specifically, multiple limiting posts 30 are arranged at intervals along the length direction perpendicular to the leads 200. Two adjacent limiting posts 30 can isolate one lead 30 from other leads 30, and there is no contact between them. Among them, the wire material 23 includes a core wire 230 connected to the lead 200 and an epidermis 231 wrapped outside the core wire 230. In the docking process, the epidermis 231 at the connection part needs to be removed to facilitate the electrical connection between the core wire 230 and the lead 200. After the electrical connection between the two, the enameled wire 201 is used for wrapping to avoid the exposure of the metal connection part and play an insulating role. However, due to the soft material and poor wear resistance of the enameled wire 201, and the compact structure of the multiple leads 200, there is a large amount of movement in the vibration environment, and the contact friction between the enameled wires 201 is more likely to cause wear. Therefore, by arranging the limiting posts 30 to separate the enameled wires 201 pairwise, the movement is reduced, and the contact between the enameled wires 201 outside different leads 200 is also avoided, thereby avoiding relative wear, ensuring the integrity and insulation of the enameled wire 201, and prolonging the service life.
[0045] See Figure 5 , multiple wire grooves 310 are further arranged on the extension part 31 of the fixing bracket 3, and the multiple wire materials 23 are respectively received in the multiple wire grooves 310. The wire grooves 310 adopt an open structure, and the multiple wire materials 23 are sorted into the wire grooves 310 in an intermittent manner. In this embodiment, three wire grooves 310 are provided, which are arranged corresponding to the three-phase wires, and each wire material 23 corresponds to one wire groove 310. Since the wire material 23 has a relatively loose structure, by arranging the wire grooves 310, the wire material 23 can be completely received in the groove body, with clear classification and the avoidance of mutual entanglement.
[0046] See also Figure 2 A limit plate 33 is arranged above the opening of the wire slot 310. The limit plate 33 is arranged horizontally on the wire slot 310 and can seal the opening of the wire slot 310 to prevent the wire 23 from escaping from the wire slot 310. Both ends of the limit plate 33 are fixedly connected to the lower bracket 1 by screws 34. The shape of the limit plate 33 adopts a strip-shaped structure. In this application, the number of limit plates 33 is one. The number of limit plates can be adaptively adjusted according to the lead-out strengths of the wire 23, which will not be described here.
[0047] The lower bracket 1 is provided with columns 12 at positions corresponding to the screws 34 , and the columns 12 are provided with threaded holes 120 for coupling with the screws 34 . In this embodiment, the two columns 12 are located on both sides of the extension portion 31 of the fixing frame 3 and can limit the extension portion 31 .
[0048] See also Figure 4 The lower bracket 1 includes a main body 11 and an extension portion 10 integrally formed with the main body 11. The extension portion 10 extends axially and is hollow. The stator core 21, the first bracket 220 and the second bracket 221 are all sleeved on the extension portion 10 of the lower bracket 1. The rotating shaft 5 passes through the extension portion 10 and is coaxially arranged with the extension portion 10.
[0049] See also Figure 4 , Figures 6-7 The main body 11 is formed with a convex portion 110, and the fixing frame 3 is provided with a concave portion 35 matched with the convex portion 110. After installation, the inner wall of the concave portion 35 can fit the outer wall of the concave portion 110. Among them, the end of the extension portion 10 adjacent to the stator core 21 is formed with a first bearing chamber 13, and the brushless motor includes at least one first bearing 6, which is sleeved on the rotating shaft 5 and placed in the first bearing chamber 13; the part of the inner wall of the convex portion 110 is formed with a second bearing chamber 14, and the brushless motor also includes at least one second bearing 7, which is sleeved on the rotating shaft 5 and placed in the second bearing chamber 14. The arrangement of the first bearing 6 and the second bearing 7 can ensure the stable rotation of the rotating shaft 5; and the integrated design of the main body 11 and the extension portion 10, on the one hand, has a more compact structure, and on the other hand, the first bearing chamber 13 and the second bearing chamber 14 are both located on the extension portion 10, thereby ensuring concentricity. In a vibration environment, the stability of the axis of the rotating shaft 5 and the theoretical center line can still be guaranteed, thereby ensuring the stability and safety of the operation of the cutter head.
[0050] See also Figure 5 The fixing frame 3 is provided with an avoidance hole 32 for the extension portion 10 of the lower bracket 1 to pass through, and an end wall 320 forming the avoidance hole 32 abuts against the other side of the first bracket 220 .
[0051] See alsoFigure 4 , the rotor assembly 4 includes a rotating housing 40 and permanent magnets 41 fixed on the rotating housing 40, and the rotating housing 40 is in interference fit with the rotating shaft 5. When the stator winding 20 is energized, a changing magnetic field is generated. Under the action of the magnetic field, the permanent magnets 41 drive the rotating housing 40 to rotate, and the rotating housing 40 drives the rotating shaft 5 to rotate synchronously.
[0052] The brushless motor further includes a fan 8 and a gear 9, and both the fan 8 and the gear 9 are in interference fit with the rotating shaft 5.
[0053] The above-described embodiments merely represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed. However, it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.
Claims
1. A brushless motor for a garden tool, the garden tool comprising a lower bracket (1), the brushless motor comprising a stator assembly (2), the stator assembly (2) comprising a stator winding (20), characterized in that: The brushless motor further comprises a fixing frame (3), the fixing frame (3) having a first surface and a second surface opposite to each other in the axial direction, the stator winding (20) being located on one side of the first surface, the lower bracket (1) being located on one side of the second surface, and the lead wire (200) on the stator winding (20) passing through a gap between the stator winding (20) and the first surface; Wherein, the fixing frame (3) is made of insulating material; The fixing frame (3) is concave inwardly along the axial direction and passes over the lead wire (200), so that the lead wire (200) and the lower bracket (1) are relatively isolated, thereby preventing the current on the lead wire (200) from being conducted to the lower bracket (1).
2. The brushless motor according to claim 1, characterized in that: The inner recess (36) of the fixing frame (3) abuts against the insulating portion (202) of the stator winding (20), so that the lead wire (200) and the lower bracket (1) are relatively insulated and isolated.
3. The brushless motor according to claim 1, characterized in that: The plurality of lead wires (200) are all externally connected to a wire (23), and the connection between each lead wire (200) and the wire (23) is wrapped with an enameled wire (201). A limiting column (30) is protruding from the fixing frame (3), and the limiting column (30) is used to isolate the enameled wires (201) outside different lead wires (200) from each other.
4. The brushless motor according to claim 3, characterized in that: A plurality of wire grooves (310) are also provided on the extended portion (31) of the fixing frame (3), and a plurality of wires (23) are accommodated in the plurality of wire grooves (310) in a one-to-one correspondence.
5. The brushless motor according to claim 4, characterized in that: A limiting plate (33) is provided above the wire groove (310) to prevent the wire (23) from escaping from the wire groove (310), and both ends of the limiting plate (33) are fixedly connected to the lower bracket (1) via screws (34).
6. The brushless motor according to claim 5, characterized in that: The lower bracket (1) is provided with a column (12) at a position corresponding to the screw (34), the column (12) is provided with a threaded hole (120) matched with the screw (34), and the column (12) can limit the extension portion (31).
7. The brushless motor according to claim 1, characterized in that: The stator assembly (2) further comprises a stator core (21), wherein the stator core (21) is sleeved on the extension portion (10) of the lower bracket (1).
8. The brushless motor according to claim 7, characterized in that: The stator assembly (2) further comprises a stator bracket (22), wherein the stator bracket (22) comprises a first bracket (220), wherein the first bracket (220) is sleeved on the extension portion (10) of the lower bracket (1), and one side of the first bracket (220) is matched with one side of the stator core (21), and the other side of the first bracket (220) is in contact with the fixing frame (3).
9. The brushless motor according to claim 8, characterized in that: The fixing frame (3) is provided with an avoidance hole (32) for the extension portion (10) of the lower bracket (1) to pass through.
10. The brushless motor according to claim 9, characterized in that: The end wall (320) forming the avoidance hole (32) abuts against the other side of the first bracket (220).
11. The brushless motor according to claim 8, characterized in that: The stator bracket (22) further comprises a second bracket (221), the second bracket (221) being sleeved on the extension portion (10) of the lower bracket (1), and the second bracket (221) being matched with the other side of the stator core (21).
12. The brushless motor according to claim 7, characterized in that: The brushless motor further comprises a rotor assembly (4) and a rotating shaft (5); the rotor assembly (4) comprises a rotating shell (40) and a permanent magnet (41) fixed on the rotating shell (40); the rotating shell (40) and the rotating shaft (5) are interference fit.
13. The brushless motor according to claim 12, characterized in that: The lower bracket (1) comprises a main body (11) and an extension portion (10) integrally formed with the main body (11); the extension portion (10) extends axially and is hollow; the rotating shaft (5) passes through the extension portion (10) and is coaxially arranged with the extension portion (10).
14. The brushless motor according to claim 13, characterized in that: The brushless motor further comprises at least one first bearing (6); a first bearing chamber (13) is formed at one end of the extension portion (10) adjacent to the stator core (21); the first bearing (6) is sleeved on the rotating shaft (5) and disposed in the first bearing chamber (13).
15. The brushless motor according to claim 13, characterized in that: The brushless motor further comprises at least one second bearing (7), a second bearing chamber (14) being formed in the lower bracket (1), and the second bearing (7) being sleeved on the rotating shaft (5) and disposed in the second bearing chamber (14).
16. The brushless motor according to claim 15, characterized in that: The second bearing chamber (14) is formed in a partial space of an inner wall of the convex portion (110) of the main body (11) or on the extended portion (10).