A brushless motor for a tool

Abstract

The utility model relates to a kind of brushless motor for tool, belong to electric tool technical field.The motor includes the stator formed by stator core and the insulation bobbin embedded therein;Bobbin at least one end has three spaced apart axial direction outward extending positioning column;Positioning column inserts wiring terminal;Wiring terminal has the middle part Ω shape insertion slot compatible with positioning column, the two sides of Ω shape insertion slot respectively tangentially extend out wiring arm and winding arm, the outer end of wiring arm is bent out radial direction outward extending terminal lug, and the middle part of terminal lug has threading hole compatible with power cord;The middle part of winding arm extends out axial Y shape winding rod.The utility model inserts conveniently, and positioning is reliable;It can be conveniently inserted into power cord after stripping metal core along tangential direction, and then welded, to ensure reliable electrical connection;And the straight rod section of Y shape winding rod is used to wind motor winding enameled wire, fork mouth part is used to set up enameled wire end head exposed metal core and then welded, to ensure reliable electrical connection.

Description

Technical Field

[0001] This utility model relates to a brushless motor, and more particularly to a brushless motor for power tools, belonging to the field of power tool technology. Background Technology

[0002] US Patent No. 11646626B and European Patent No. EP2675041 disclose brushless motors for power tools. While these patented technologies each have their advantages, the wiring structure during assembly is relatively complex, and the axial extension of external wires occupies a significant amount of axial space. Furthermore, the separate assembly of the front and rear winding frames inevitably leaves a certain assembly gap, posing a safety hazard for BLAC high-voltage appliances with strict electrical distance requirements.

[0003] To overcome the shortcomings of the existing technology, Chinese patent application No. 2025206560208 proposes a brushless motor for power tools, comprising: a stator and a rotor rotatably housed within the stator; the rotor includes a rotor body with embedded magnets, and rotor shafts extending from both ends of the rotor body; the stator consists of an insulating cylindrical winding frame and a stator core covering the winding frame; one end of the winding frame has a plug-in structure with at least three terminals and a fixing structure for connecting pieces; one end of each terminal is a tangential power supply fixing end, and the other end is a winding end; and it also has a downwardly extending plug-in end. During assembly, one end of each of the three windings of the brushless motor is electrically connected to the connecting piece, and then the other end of each of the three windings is electrically connected to the winding ends of the three terminals, allowing for convenient external connection of three-phase power leads from the circuit board. Therefore, the structure is simple, assembly is convenient, and the tangentially extended external wires save axial space. However, in practice, the following shortcomings have been found: 1) The positioning and installation of the terminals are not convenient and reliable enough; 2) It is not easy to ensure the welding quality of the enameled wire ends of the motor windings; 3) The pre-crimping of the power supply wires is not convenient and reliable enough. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of the existing technology by proposing a tool brushless motor that provides reliable wiring and positioning and ensures high-quality welding of the power line and motor winding ends while maintaining a compact axial structure.

[0005] To achieve the above objectives, the basic technical solution of the brushless motor for tools of this utility model is as follows: It includes a stator composed of a stator core and an insulated winding frame embedded therein; the winding frame has at least three axially outwardly extending positioning posts at intervals at one end; terminals are inserted into the positioning posts; the terminals have a central Ω-shaped slot adapted to the positioning posts, and connecting arms and winding arms extend tangentially from both sides of the Ω-shaped slot, respectively; the outer ends of the connecting arms are bent into radially outwardly extending connecting pieces, and the middle of the connecting pieces has a through hole adapted to the power cord; an axially extending Y-shaped winding rod extends from the middle of the winding arm.

[0006] Because the Ω-shaped slot structure of this utility model has ideal elasticity, it is easy to insert and reliably positioned; the connecting piece with the wire hole in the middle can be easily inserted tangentially into the power wire with the metal core stripped and then welded, ensuring a reliable electrical connection; while the straight section of the Y-shaped winding rod is used to wind the enameled wire of the motor winding, and the fork part is used to place the exposed metal core of the enameled wire end and then weld it, ensuring a reliable electrical connection.

[0007] A further improvement of this utility model is that the bent part of the connecting arm has an axially extending positioning protrusion; one end of the winding frame has an L-shaped groove that matches the positioning protrusion.

[0008] A further improvement to this utility model is that the outer end of the winding arm is bent to form a hook that extends radially inward, and at least one end of the winding frame has a hook groove that matches the position of the hook.

[0009] The above-mentioned improvements can more effectively constrain the planar and rotational degrees of freedom of the terminals, making them more stable after insertion.

[0010] A further improvement of this utility model is that the positioning post has positioning ribs extending radially inward.

[0011] The present invention is further improved in that: a connecting arc plate is fixed on the other half of one end of the winding frame.

[0012] A further improvement to this utility model is that the winding frame has an axial boss near the positioning post.

[0013] The present invention is further improved by having an inverted T-shaped gap in the middle of the connecting arm.

[0014] A further improvement of this utility model is that the middle part of the connector has a through hole that is adapted to the metal core of the power cord.

[0015] A further improvement of this utility model is that the middle part of the connector has a through hole adapted to the external insulation of the power line, and the middle part of the connector arm has a V-shaped gap. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the stator three-dimensional structure of Embodiment 1 of this utility model.

[0018] Figure 2 yes Figure 1 A partially enlarged structural diagram of point A in the embodiment.

[0019] Figure 3 yes Figure 1 A three-dimensional exploded view of the embodiment.

[0020] Figure 4 yes Figure 1 A three-dimensional structural diagram of the wiring terminal in the embodiment.

[0021] Figure 5 This is a three-dimensional structural diagram of the wiring terminal of Embodiment 2 of this utility model. Detailed Implementation Example 1

[0022] The basic structure of the brushless motor for power tools in this embodiment is the same as that of the prior art, consisting of a rotor (not shown in the figure) and a stator. Figures 1 to 3 As shown, its stator consists of a stator core 1 and an insulated winding frame 2 embedded therein.

[0023] One end 2.1 of the winding frame 2 has three axially outwardly extending positioning posts 2.4 distributed in a half circle. The positioning posts 2.4 have positioning ribs 2.6 extending radially inward. Each positioning post 2.4 is fitted with a terminal block 5.

[0024] Terminal 5, for example Figure 4 As shown, the device has a central Ω-shaped slot 5.1 adapted to the positioning post 2.4. A wiring arm 5.6 extends tangentially from one side of the Ω-shaped slot 5.1, and a winding arm 5.3 extends tangentially from the lower part of the other side. The outer end of the wiring arm 5.6 bends outward to form a radially outward extending wiring piece 5.9. The middle of the wiring piece 5.9 has a wire hole 5.8 adapted to the metal core of the power cord 4, and the bend has an axially extending positioning protrusion 5.7; the positioning protrusion 5.7 is adapted to the L-shaped slot 2.3 at one end 2.1 of the winding frame 2. An axially extending Y-shaped winding rod 5.2 extends from the middle of the winding arm 5.3, and the outer end bends outward to form a hook 5.4 that extends both radially and axially inward. One end of the winding frame 2 has a hook groove 2.5 corresponding to the position of the hook 5.4.

[0025] In addition, a connecting arc plate 3 is fixed to the other half of one end 2.1 of the winding frame 2 to realize the series or parallel electrical connection of the motor windings. The winding frame 2 has an axial boss 2.2 near the positioning post 2.4 to block the power line 4. The middle part of the connecting arm 5.6 has an inverted T-shaped gap 5.10, which is used so that when the enamel section of the enameled wire 6 is too long, it can first be wound through the inverted T-shaped gap 5.10 and then wound to the Y-shaped winding rod 5.2, thereby ensuring that the exposed metal core of the enameled wire 6 overlaps with the fork of the Y-shaped winding rod 5.2 before welding.

[0026] When wiring using this embodiment, the terminal block 5 is inserted into the positioning post 2.4. The elasticity of its Ω-shaped slot 5.1 and the synergistic effect of the L-shaped slot 2.3, hook slot 2.5, and positioning rib 2.6 on one end 2.1 of the winding frame 2 ensure that the terminal block 5 is firmly and reliably installed. Then, the corresponding ends of each winding of the motor are connected in series or in parallel with the help of the wiring arc plate 3. The power end of the enameled wire 6 of each winding is wound around the straight section of the Y-shaped winding rod 5.2. The fork part is used to place the exposed metal core of the enameled wire 6 end for welding. After that, the metal core stripped from the power wire 4 is inserted tangentially into the matching wire hole 5.8 and then welded to ensure a reliable electrical connection.

[0027] In summary, this embodiment has the following significant advantages: 1) The Ω-shaped slot has a certain degree of elasticity and can be easily and reliably inserted into the positioning post of the winding machine frame; 2) The neck of the Y-shaped winding rod structure facilitates the winding of the enameled wire, as well as the placement of the wire ends for welding. 3) The L-shaped slots, hook slots, and positioning ribs of the terminals are matched with the corresponding structures of the winding frame, which reliably constrains the planar and rotational degrees of freedom. 4) The connector structure with wiring holes facilitates circumferential welding of power lines and saves axial space. Example 2

[0028] The basic structure of the brushless motor for the power tool in this embodiment is the same as that in Embodiment 1, except that: the terminal block 5.9 has a through hole 5.8 in the middle that is adapted to the outer insulation of the power cord 4, and the terminal arm 5.6 has a V-shaped gap 5.10' in the middle. During electrical connection, the outer insulation of the power cord 4 is first passed through the through hole 5.8, and the stripped metal core of the power cord 4 is bent and placed over the V-shaped gap 5.10' before welding. In this way, the root of the solder joint can be effectively protected, and the electrical connection is more reliable.

[0029] In addition to the embodiments described above, this utility model may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by this utility model.

Claims

1. A brushless motor for tools, characterized in that: The stator comprises a stator core and an insulated winding frame embedded therein; the winding frame has at least one end three axially outwardly extending positioning posts spaced apart; terminals are inserted into the positioning posts; the terminals have a central Ω-shaped slot adapted to the positioning posts, and wiring arms and winding arms extend tangentially from both sides of the Ω-shaped slot, respectively; the outer ends of the wiring arms are bent into radially outwardly extending wiring pieces, and the middle of the wiring pieces has a through hole adapted to the power line; an axially extending Y-shaped winding rod extends from the middle of the winding arm.

2. The brushless motor for tools according to claim 1, characterized in that: The bend of the connecting arm has an axially extending positioning protrusion; one end of the winding frame has an L-shaped slot that matches the positioning protrusion.

3. The brushless motor for tools according to claim 2, characterized in that: The outer end of the winding arm is bent to form a hook that extends radially inward, and at least one end of the winding frame has a hook groove that matches the position of the hook.

4. The brushless motor for tools according to claim 3, characterized in that: The positioning post has positioning ribs that extend radially inward.

5. The brushless motor for tools according to claim 4, characterized in that: The other half of the winding frame is fixed with a connecting arc plate.

6. The brushless motor for tools according to claim 5, characterized in that: The winding frame has an axial boss near the positioning post.

7. The brushless motor for tools according to claim 6, characterized in that: The middle of the connector arm has an inverted T-shaped gap.

8. The brushless motor for tools according to any one of claims 1 to 6, characterized in that: The connector has a through hole in the middle that is adapted to the metal core of the power cord.

9. The brushless motor for tools according to any one of claims 1 to 6, characterized in that: The terminal block has a through hole in the middle that is adapted to the external insulation of the power line, and the terminal arm has a V-shaped gap in the middle.

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