Brushless motor for garden tool

Abstract

Disclosed in the present utility model is a brushless motor for a garden tool. The garden tool comprises a lower support; the brushless motor comprises a stator assembly; the stator assembly comprises a stator winding; the brushless motor further comprises a fixing support; the fixing support has a first surface and a second surface facing away from each other in an axial direction; the stator winding is located on the side of the first surface; the lower support is located on the side of the second surface; and leads on the stator winding extend out of a gap between the stator winding and the first surface. The fixing support is made of an insulating material; the fixing support is recessed inward in the axial direction and passes over the leads, so that the leads and the lower support are relatively isolated, and the current on the leads is prevented from being conducted to the lower support. The present utility model can avoid the shortcoming that a cutter head is electrified due to the current on the leads being conducted to the lower support; and in addition, the present utility model involves low production costs, and avoids the occurrence of damage to enameled wires.

Description

A brushless motor for garden tools TECHNICAL FIELD

[0001] The utility model relates to garden tool technical field, especially a kind of brushless motor for garden tools. BACKGROUND

[0002] Most of garden tools are of handheld structure, and the safety performance is more strictly required to prevent the tool from being electrified, so that the user has the risk of electric shock during operation. The brushless motor is frequently used in garden tools. In the traditional brushless outer rotor motor, the wire of the stator winding is only wrapped with enameled wire, and is not fixed. During the grass cutting process, vibration occurs, and the position of the lead wire moves downward along the axis. Since the safety distance between the lead wire and the lower support is short, the lead wire and the lower support are in contact, and then electrification occurs. The electrification is transmitted to the cutter head, which affects the safety of the motor itself and the operator.

[0003] To solve the above problems, the current solution is to increase the axial length of the motor to increase the safety distance, and to increase the pressing and shaping process of the wire outlet on the process side. However, such operation not only increases the production cost, but also may damage the enameled wire during the pressing process, resulting in low product qualification rate.

[0004] UTILITY MODEL CONTENTS

[0005] In view of the deficiencies of the prior art, the utility model provides a brushless motor for garden tools, which can avoid the current on the lead wire from being conducted to the lower support, resulting in the electrification of the cutter head, and has low production cost and avoids the damage of the enameled wire.

[0006] The utility model realizes the following technical solutions:

[0007] A brushless motor for garden tools, the garden tool comprising a lower support, the brushless motor comprising a stator assembly, the stator assembly comprising a stator winding, the brushless motor further comprising a fixing frame, the fixing frame having opposite first and second surfaces along the axial direction, the stator winding being located on the side of the first surface, the lower support being located on the side of the second surface, and the lead wire on the stator winding passing through the gap between the stator winding and the first surface;

[0008] The fixing frame is made of insulating material;

[0009] The fixing frame is concave along the axial direction and passes over the lead wire, so that the lead wire and the lower support are relatively isolated, and the current on the lead wire is prevented from being conducted to the lower support.

[0010] Further, the plurality of lead wires are each externally connected with a wire, and the connection between each of the lead wires and the wire is wrapped with an enameled wire, a limiting column is protruded on the fixing frame, and the limiting column is used to isolate the enameled wires on the outer sides of different lead wires from each other.

[0011] Further, the plurality of lead wires are each externally connected with a wire, and the connection between each of the lead wires and the wire is wrapped with an enameled wire, a limiting column is protruded on the fixing frame, and the limiting column is used to isolate the enameled wires on the outer sides of different lead wires from each other.

[0012] Further, a plurality of wire grooves are further arranged on the extension part of the fixing frame, and the plurality of wires are correspondingly accommodated in the plurality of wire grooves.

[0013] Further, a limiting plate is arranged above the wire groove to prevent the wire from being separated from the wire groove, and both ends of the limiting plate are fixedly connected with the lower support through screws.

[0014] Further, a stand column is arranged on the lower support corresponding to the position of the screw, a threaded hole matched with the screw is formed in the stand column, and the stand column can limit the extension part.

[0015] Further, the stator assembly further comprises a stator core, and the stator core is sleeved on the extension part of the lower support.

[0016] Further, the stator assembly further comprises a stator support, the stator support comprises a first support, the first support is sleeved on the extension part of the lower support, one side of the first support is matched with one side of the stator core, and the other side of the first support is abutted with the fixing frame.

[0017] Further, an avoiding hole is formed in the fixing frame to allow the extension part of the lower support to pass through.

[0018] Further, the end wall forming the avoiding hole is abutted with the other side of the first support.

[0019] Further, the stator support further comprises a second support, the second support is sleeved on the extension part of the lower support, and the second support is matched with the other side of the stator core.

[0020] Further, the brushless motor further comprises a rotor assembly and a rotating shaft, the rotor assembly comprises a rotating shell and a permanent magnet fixed on the rotating shell, and the rotating shell is interference-fitted with the rotating shaft.

[0021] Further, the lower support comprises a body part and the extension part integrally formed with the body part, the extension part extends along the axial direction and is in a hollow shape, the rotating shaft is arranged in the extension part and is coaxially arranged with the extension part.

[0022] Further, the brushless motor further comprises at least one first bearing, the extension part is formed with a first bearing chamber at one end of the stator core, and the first bearing is sleeved on the rotating shaft and arranged in the first bearing chamber.

[0023] Further, the brushless motor further comprises at least one second bearing, the lower support is formed with a second bearing chamber, and the second bearing is sleeved on the rotating shaft and arranged in the second bearing chamber.

[0024] Further, the second bearing chamber is formed in part of the inner wall of the convex part of the body part or on the extension part.

[0025] Compared with the prior art, the utility model has the advantages that:

[0026] 1. The fixing frame is made of insulating material and arranged between the lower support and the stator winding, the multiple lead wires of the stator winding are isolated in the space on the two sides of the fixing frame in the axial and radial directions, so as to avoid the current on the lead wires from being conducted to the lower support made of metal material, thereby avoiding the disadvantage that the current is conducted to the electrically charged tool bit, and compared with the prior art, the production cost is low and the condition that the enameled wire is damaged is avoided.

[0027] 2. The first support at the bottom of the stator core abuts against the fixing frame, an isolation wall is formed between the first support and the fixing frame in the axial direction, the lead wires and the lower support are further insulated and isolated in the space on the two sides of the isolation wall, and the risk that the current on the lead wires is conducted to the lower support due to vibration is further avoided.

[0028] 3. The wire slot is arranged to completely accommodate the wire in the groove, the classification is clear, and the mutual entanglement is avoided, and the limiting plate is arranged above the wire slot to avoid the wire from being separated from the wire slot.

[0029] 4. The limiting column is arranged to separate the enameled wires, reduce the movement, avoid the contact between the enameled wires outside different lead wires, thereby avoid the relative abrasion, ensure the integrity and insulation of the enameled wires, and prolong the service life. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 is a structural schematic view of the brushless motor;

[0031] Fig. 2 is a partial structural schematic view of the brushless motor;

[0032] Fig. 3 is a partial structural schematic view of the stator assembly;

[0033] Fig. 4 is a sectional view of the brushless motor;

[0034] Fig. 5 is a structural schematic view of the fixing frame; and

[0035] Fig. 6 is a schematic view of the structure of the fixing frame;

[0036] Fig. 7 is a schematic view of the structure of the lower support.

[0037] 1, lower support; 10, extension; 11, body part; 110, convex part; 12, upright; 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 support; 220, first support; 221, second support; 222, fitting column; 23, wire; 230, core wire; 231, skin; 3, fixing frame; 30, limiting column; 31, extension; 310, wire slot; 32, avoiding hole; 320, end wall; 33, limiting plate; 34, screw; 35, recess; 36, inner recess; 4, rotor assembly; 40, rotating shell; 41, permanent magnet; 5, rotating shaft; 6, first bearing; 7, second bearing; 8, fan; 9, gear. DETAILED DESCRIPTION

[0038] The utility model technical scheme will be further described in detail below in combination with the preferred embodiments and the drawings. In the description of the utility model, 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", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the utility model, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited. The embodiments described below by referring to the drawings are exemplary and are intended to explain the utility model, and cannot be understood as limiting the utility model.

[0039] As shown in FIG. 1-7, the utility model discloses an embodiment of a kind of brushless motor for garden tools, and garden tool includes lower support 1, in this embodiment, brushless motor is brushless outer rotor motor, mainly including stator assembly 2, fixed frame 3, rotor assembly 4 and rotating shaft 5, the rotor assembly 4 is arranged at the outer side of stator assembly 2, rotating shaft 5 passes through stator assembly 2 and is interference fit with rotor assembly 4.When stator assembly 2 is powered, the magnetic field that can cooperate rotor assembly 4 is generated, to drive rotor assembly 4 to rotate and drive rotating shaft 5 synchronous rotation in turn. Wherein, stator assembly 2, rotor assembly 4 and rotating shaft 5 are coaxially arranged.

[0040] Stator assembly 2 includes stator winding 20, stator core 21 and stator support 22, stator support 22 includes first support 220 and second support 221, stator core 21 is located between first support 220 and second support 221 along the axial direction, and one side of first support 220 is connected with one side of stator core 21, and the other side is abutted with fixed frame 3, and second support 221 is connected with the other side of stator core 21, wherein stator support 22 is insulating material.

[0041] Fixed frame 3 has opposite first surface and second surface along the axial direction, stator winding 20 is located on the side of first surface, and lower support 1 is located on the side of second surface, and lead 200 on stator winding 20 is led out from the gap between stator winding 20 and first surface;Fixed frame 3 is concave along the axial direction, and crosses lead 200, so that lead 200 and lower support 1 are relatively isolated, to avoid current on lead 200 from being conducted to lower support 1.

[0042] Further, the concave part 36 of fixed frame 3 is abutted with the insulating part 202 of stator winding 20, so that lead 200 and lower support 1 are relatively insulated and isolated.

[0043] As shown in FIG. 3, the stator core 21 is provided with an adapter hole 210, and the first support 220 and the second support 221 are provided with an adapter column 222, and the adapter column 220 is connected with the adapter hole 210.

[0044] The fixing frame 3 is made of insulating material and is arranged between the lower support 1 and the stator winding 20. In one way, the other side of the first support 220 abuts against the fixing frame 3, and the abutting parts of the two are located on the inner side of the plurality of lead wires 200 of the stator winding 20, so that the plurality of lead wires 200 and the lower support 1 can be completely separated in the space on both sides of the fixing frame 3, thereby completely avoiding the contact between the plurality of lead wires 200 and the lower support 1, and further avoiding the conduction of the current on the plurality of lead wires 200 to the lower support 1 and then to the tool bit. The application adopts this way. In another way, the fixing frame 3 is concave in the axial direction and passes through the lead-out parts of the plurality of lead wires 200 of the stator winding 20, which can also separate the plurality of lead wires 200 and the lower support 1 in the space on both sides of the fixing frame 3. The vibration in the working environment will not make any lead wire 200 shake and contact the lower support 1, thereby avoiding the conduction of the current on the plurality of lead wires 200 to the lower support 1 and then to the tool bit.

[0045] Each of the plurality of lead wires 200 is externally connected with a wire 23, and the connection part of each lead wire 200 and the wire 23 is wrapped with an enameled wire 201. The fixing frame 3 is provided with a limiting column 30, which is used to separate the enameled wires 201 on the outer sides of different lead wires 200 from each other. Specifically, a plurality of limiting columns 30 are arranged at intervals in the direction perpendicular to the length of the lead wire 200, and the two adjacent limiting columns 30 can separate one of the lead wires 30 from the other lead wires 30 without contact between them. Among them, the wire 23 includes a core wire 230 connected with the lead wire 200 and a skin 231 wrapped on the outer side of the core wire 230. In the connection process, the skin 231 at the connection part needs to be removed to facilitate the electrical connection between the core wire 230 and the lead wire 200, and after the electrical connection, the enameled wire 201 is wrapped to avoid the exposure of the metal connection part and play the insulation role. However, because the enameled wire 201 is soft and has poor wear resistance, and the plurality of lead wires 200 are compact in structure and have a large amount of movement in the vibration environment, the enameled wires 201 are more prone to wear and tear due to contact and friction between them. Therefore, by arranging the limiting column 30 to separate the enameled wires 201 from each other, the movement is reduced, and the contact between the enameled wires 201 on the outer sides of different lead wires 200 is avoided, thereby avoiding relative wear and tear, ensuring the integrity and insulation of the enameled wire 201, and prolonging the service life.

[0046] Referring to FIG. 5, the extension part 31 of the fixing frame 3 is further provided with a plurality of wire grooves 310, and the plurality of wires 23 are correspondingly accommodated in the plurality of wire grooves 310. The wire groove 310 adopts an open structure, and the plurality of wires 23 are arranged in the wire groove 310 in a gap type. In this embodiment, the wire groove 310 is provided with three wire grooves corresponding to three-phase wires, and each wire 23 corresponds to one wire groove 310. Because the wire 23 is relatively loose in structure, by arranging the wire groove 310 to completely accommodate the wire 23 in the groove body, the classification is clear, and the mutual entanglement can be avoided.

[0047] Referring to FIG. 2, a limiting plate 33 is arranged above the opening of the wire slot 310, the limiting plate 33 is arranged horizontally on the wire slot 310, and can play a closing role on the opening of the wire slot 310 to avoid the wire 23 from being separated from the wire slot 310. Both ends of the limiting plate 33 are fixedly connected with the lower support 1 through screws 34. The shape of the limiting plate 33 adopts a strip shape structure, and in the present application, the number of the limiting plate 33 is one. The number of the limiting plate can be adaptively adjusted according to the length of the wire 23, which will not be repeated here.

[0048] The lower support 1 is provided with a stand 12 corresponding to the position of the screw 34, and the stand 12 is provided with a threaded hole 120 matched with the screw 34. In the embodiment, the two stands 11 are located on both sides of the extendable part 31 of the fixed frame 3.

[0049] Referring to FIG. 4, the lower support 1 includes a body part 11 and an extension part 10 integrally formed with the body part 11. The extension part 10 extends along the axial direction and is hollow. The stator core 21, the first support 220 and the second support 221 are sleeved on the extension part 10 of the lower support 1. The rotating shaft 5 is arranged in the extension part 10 and coaxially arranged with the extension part 10.

[0050] Referring to FIGS. 4, 6 and 7, the body part 11 is formed with a convex part 110, and the fixed frame 3 is provided with a concave part 35 matched with the convex part 110. After installation, the inner side wall of the concave part 35 can be attached to the outer side wall of the convex part 110. The end of the extension part 10 close to the stator core 21 is formed with a first bearing chamber 13. The brushless motor includes at least one first bearing 6, which is sleeved on the rotating shaft 5 and arranged in the first bearing chamber 13. Part of the space of the inner side wall of the convex part 110 is formed with a second bearing chamber 14. The brushless motor also includes at least one second bearing 7, which is sleeved on the rotating shaft 5 and arranged 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. The integration of the body part 11 and the extension part 10 can make the structure more compact, and the first bearing chamber 13 and the second bearing chamber 14 are both arranged on the extension part 10, so as to ensure the concentricity. In the vibration environment, the stability of the axis of the rotating shaft 5 and the theoretical center line can still be ensured, so as to ensure the stability and safety of the tool bit operation.

[0051] Referring to FIG. 5, the fixed frame 3 is provided with a relief hole 32 for the extension part 10 of the lower support 1 to pass through, and the end wall 320 forming the relief hole 32 abuts against the other side of the first support 220.

[0052] Referring to Fig. 4, the rotor assembly 4 comprises a rotating shell 40 and permanent magnets 41 fixed on the rotating shell 40, and the rotating shell 40 is in interference fit with the rotating shaft 5. When the stator winding 20 is powered, a changing magnetic field is generated, and the permanent magnets 41 drive the rotating shell 40 to rotate under the action of the magnetic field, and the rotating shell 40 rotates synchronously with the rotating shaft 5.

[0053] The brushless motor further comprises a fan 8 and a gear 9, both of which are in interference fit with the rotating shaft 5.

[0054] The above-described embodiments only express several implementation manners of the utility model, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the patent scope of the utility model. It should be noted that, for ordinary skilled persons in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. A brushless motor for garden tools, the garden tools 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 fixed frame (3) having opposite first and second surfaces in the axial direction, the stator winding (20) is located on the first surface side, the lower support (1) is located on the second surface side, and the lead wire (200) on the stator winding (20) passes out of the gap between the stator winding (20) and the first surface; The fixed frame (3) is made of insulating material. The fixed frame (3) is concave in the axial direction and passes over the lead wire (200), so that the lead wire (200) and the lower support (1) are relatively isolated, and the current on the lead wire (200) is prevented from being conducted to the lower support (1).

2. The brushless motor of claim 1, wherein, The concave part (36) of the fixed frame (3) abuts against the insulating part (202) of the stator winding (20), so that the lead wire (200) and the lower support (1) are relatively insulated and isolated.

3. The brushless motor of claim 1, wherein, Each of the plurality of lead wires (200) is externally connected to a wire (23), and the connection between each of the lead wires (200) and the wire (23) is wrapped with an enameled wire (201), the fixed frame (3) is provided with a limiting column (30), and the limiting column (30) is used to isolate the enameled wires (201) on the outer sides of different lead wires (200) from each other.

4. The brushless motor of claim 3, wherein, The extension part (31) of the fixed frame (3) is further provided with a plurality of wire grooves (310), and the plurality of wires (23) are correspondingly accommodated in the plurality of wire grooves (310).

5. The brushless motor of claim 4, wherein, A limiting plate (33) is arranged above the wire groove (310) to prevent the wire (23) from being separated from the wire groove (310), and both ends of the limiting plate (33) are fixedly connected to the lower support (1) through screws (34).

6. The brushless motor of claim 5, wherein, The lower support (1) is provided with a stand column (12) corresponding to the position of the screw (34), the stand column (12) is provided with a threaded hole (120) matched with the screw (34), and the stand column (11) can limit the extension part (31).

7. The brushless motor of claim 1, wherein, The stator assembly (2) further comprises a stator core (21) sleeved on the extension part (10) of the lower support (1).

8. The brushless motor of claim 7, wherein, The stator support (22) comprises a first support (220) sleeved on the extension part (10) of the lower support (1), one side of the first support (220) is matched with one side of the stator core (21), and the other side is abutted against the fixed frame (3).

9. The brushless motor of claim 8, wherein, The fixed frame (3) is provided with a relief hole (32) for the extension part (10) of the lower support (1) to pass through.

10. The brushless motor of claim 9, wherein, An end wall (320) forming the relief hole (32) abuts against the other side of the first support (220).

11. The brushless motor of claim 8, wherein, The stator support (22) further comprises a second support (221) sleeved on the extension part (10) of the lower support (1), and the second support (221) is matched with the other side of the stator core (21).

12. The brushless motor of claim 7, wherein, 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), and the rotating shell (40) is in interference fit with the rotating shaft (5).

13. The brushless motor of claim 12, wherein, The lower support (1) comprises a body part (11) and the extension part (10) integrally formed with the body part (11), the extension part (10) extends in the axial direction and is hollow, the rotating shaft (5) is arranged in the extension part (10) and is coaxial with the extension part (10).

14. The brushless motor of claim 13, wherein, The brushless motor further comprises at least one first bearing (6), one end of the extension part (10) is formed with a first bearing cavity (13) adjacent to the stator core (21), and the first bearing (6) is sleeved on the rotating shaft (5) and arranged in the first bearing cavity (13).

15. The brushless motor of claim 13, wherein, The brushless motor further comprises at least one second bearing (7), and the lower support (1) is formed with a second bearing cavity (14), the second bearing (7) is sleeved on the rotating shaft (5) and arranged in the second bearing cavity (14).

16. The brushless motor of claim 15, wherein, The second bearing cavity (14) is formed in the space of the inner wall of the convex part (110) of the body part (11) or on the extension part (10).

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