阅读说明：本技术 无刷马达总成 (Brushless motor assembly ) 是由 洪文星 王士豪 于 2020-03-25 设计创作，主要内容包括：一种无刷马达总成,包含一马达本体、一电路板与多个电子元件,所述电路板设置于所述马达本体,所述电路板具有相背对的一第一面与一第二面,所述第一面朝向所述马达本体,所述第二面具有多个导热线路。所述多个电子元件包括多个功率开关元件,所述多个功率开关元件设置于第二面。第二面上另设置多个散热块,各所述功率开关元件与各所述散热块连接于各所述导热线路,使各所述功率开关元件散发的热能经由各所述导热线路传导到各所述散热块。藉此,可减少无刷马达总成整体之体积。(A brushless motor assembly comprises a motor body, a circuit board and a plurality of electronic elements, wherein the circuit board is arranged on the motor body and is provided with a first surface and a second surface which are opposite, the first surface faces the motor body, and the second surface is provided with a plurality of heat conducting circuits. The plurality of electronic components include a plurality of power switching elements disposed on the second face. The second surface is additionally provided with a plurality of radiating blocks, and each power switch element and each radiating block are connected to each heat conducting circuit, so that the heat energy radiated by each power switch element is conducted to each radiating block through each heat conducting circuit. Thus, the overall size of the brushless motor assembly can be reduced.)

1. A brushless motor assembly, comprising:

a motor body;

the circuit board is arranged on the motor body and provided with a first surface and a second surface which are opposite, the first surface faces the motor body, and the second surface is provided with a plurality of heat conducting circuits; the second surface is provided with a plurality of power switch elements and a plurality of radiating blocks, and each power switch element and each radiating block are connected to each heat conducting circuit, so that heat energy radiated by each power switch element is conducted to each radiating block through each heat conducting circuit.

2. The brushless motor assembly of claim 1, wherein the motor body comprises a stator assembly having a front end and a rear end, and a shaft disposed in the stator assembly and extending through the front end and the rear end; the circuit board is arranged at the rear end, and the first surface faces the rear end.

3. The brushless motor assembly of claim 2, comprising a back cover coupled to the back end of the stator assembly, the back cover having an inner side, the circuit board being disposed between the inner side of the back cover and the back end, the inner side facing the second side of the circuit board.

4. The brushless motor assembly of claim 3, comprising a thermal pad disposed between the rear cover and the circuit board, the thermal pad having a first thermal conductive surface and a second thermal conductive surface opposite to each other, the first thermal conductive surface being connected to an inner side surface of the rear cover, the second thermal conductive surface being connected to the plurality of heat dissipation blocks.

5. The brushless motor assembly of claim 4, wherein a gap is provided between the second thermally conductive surface of the thermal pad and each of the power switching elements.

6. The brushless motor assembly of claim 3, wherein the circuit board has an inner ring portion and an outer ring portion, the inner ring portion has a through hole, and the shaft passes through the through hole; the outer ring portion surrounds the inner ring portion; the plurality of power switching elements are located at the outer ring portion.

7. The brushless motor assembly of claim 6, wherein the second face is provided with at least one drive element at the inner race portion, the at least one drive element for driving the plurality of power switching elements.

8. The brushless motor assembly of claim 6, wherein the rear cover has an outer peripheral portion, the outer peripheral portion being located at the periphery of the outer ring portion, the outer peripheral portion having a plurality of heat dissipation ports.

9. The brushless motor assembly of claim 8, comprising a plurality of wires, wherein one ends of the plurality of wires are connected to the plurality of stator coils of the stator assembly, the plurality of wires are wound around the second surface of the circuit board and are coupled to the circuit board, and a portion of the plurality of wires are exposed to the plurality of heat dissipation openings, respectively.

10. The brushless motor assembly of claim 6, wherein the first face is provided with a plurality of hall sensing elements at the inner race portion; the motor body comprises a rotor, the rotor is provided with magnetism, and the Hall sensing elements are used for sensing the rotation of the rotor.

Technical Field

The present invention relates to brushless motors; in particular to a direct current brushless motor assembly.

Background

It is known that most of the power motors used in many electric machines and tools are mainly direct current Brushless motors (BLDCM), which have high torque-to-inertia ratio and are free of the disadvantages of brush motors (e.g., brush wear, commutation spark, and noise).

In the dc brushless motor, a plurality of switching elements are used to switch different phases, and in the operation process of the dc brushless motor, the switching elements are power transistors and must be repeatedly switched between an on state and an off state, so the heat dissipation problem of the switching elements is a problem to be improved.

The conventional method is to stack a heat sink on the switch device, so that the heat sink is attached to the surface of the switch device, but the heat sink stacked on the switch device will increase the total thickness, which results in that the overall volume of the dc brushless motor cannot be reduced.

Disclosure of Invention

Accordingly, the present invention is directed to a brushless motor assembly, which has a reduced overall size and provides a good heat dissipation effect.

In order to achieve the above object, the present invention provides a brushless motor assembly, including a motor body and a circuit board, wherein the circuit board is disposed on the motor body, the circuit board has a first surface and a second surface opposite to each other, the first surface faces the motor body, and the second surface has a plurality of heat conducting wires; the second surface is provided with a plurality of power switch elements and a plurality of radiating blocks, and each power switch element and each radiating block are connected to each heat conducting circuit, so that heat energy radiated by each power switch element is conducted to each radiating block through each heat conducting circuit.

The brushless motor assembly has the advantages that the power switch element and the heat dissipation block are arranged on the second surface of the circuit board in parallel, the defect of total thickness increase caused by overlapping of the conventional power switch element and the heat dissipation block can be overcome, and the integral volume of the brushless motor assembly is reduced.

Drawings

Fig. 1 is a perspective view of a brushless motor assembly according to a preferred embodiment of the present invention.

Fig. 2 is a partially exploded perspective view of the brushless motor assembly of the preferred embodiment.

Fig. 3 is a rear view of the brushless motor assembly of the above preferred embodiment.

Fig. 4 is a front view of the first side of the circuit board of the above preferred embodiment.

Fig. 5 is a front view of the second side of the circuit board of the above preferred embodiment.

Fig. 6 is a schematic view showing the heat sink and the power switch element disposed on the circuit board.

FIG. 7 is a schematic view showing the thermal pad covering the heat slug.

Fig. 8 is a partial cross-sectional view taken in the direction 8-8 of fig. 3.

Detailed Description

In order to more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. Referring to fig. 1 to 8, a brushless motor assembly according to a preferred embodiment of the present invention includes a motor body 10, a circuit board 20 and a plurality of electronic components, wherein:

the motor body 10 includes a stator group 12, a rotor (not shown), and a rotating shaft 14, wherein the stator group 12 includes a stator core 122, a plurality of stator coils 124, a front insulating end plate 126, and a rear insulating end plate 128, the stator coils 124 are disposed in the stator core 122, the front insulating end plate 126 and the rear insulating end plate 128 are disposed at two ends of the stator core 122, respectively, and the front insulating end plate 126 and the rear insulating end plate 128 constitute a front end and a rear end of the stator group 12, respectively. The front insulating endplate 126 also incorporates a front cover 30.

The rotor is magnetic and located in the stator core 122, the rotating shaft 14 is combined with the rotor and a part of the rotating shaft is located in the stator assembly 12, the front end of the rotating shaft 14 penetrates through the front insulating end plate 126 and the front cover 30, and the rear end of the rotating shaft 14 penetrates through the rear insulating end plate 128 and is provided with a bearing 32.

The circuit board 20 is disposed on the motor body 10, and in this embodiment, the circuit board 20 is disposed on the rear insulating end plate 128 of the motor body 10. The circuit board 20 has a first side 202 and a second side 204, the first side 202 faces the rear insulating end plate 128, and the second side 204 faces away from the first side 202.

The first side 202 and the second side 204 are respectively provided for the plurality of electronic components. In this embodiment, the first surface 202 and the second surface 204 have a plurality of signal transmission lines (not shown) for electrically connecting the electronic components as signal transmission paths of the electronic components. The second surface 204 also has a plurality of heat conductive lines 204a (see fig. 6). The signal conducting circuit and the heat conducting circuit 204a are made of copper foil as an example.

The electronic components include a plurality of power switching elements 40, the power switching elements 40 may be MOSFETs, the power switching elements 40 are disposed on the second surface 204 and are respectively connected to the heat conductive paths 204a, each power switching element 40 may directly contact each heat conductive path 204a or be connected to the heat conductive path 204a through a heat conductive member, and the heat conductive member may be solder, heat conductive paste, or heat conductive adhesive, for example. The second surface 204 is further provided with a plurality of heat dissipating blocks 50, the heat dissipating blocks 50 are respectively connected to the plurality of heat conductive paths 204a, and each heat dissipating block 50 can directly contact each heat conductive path 204a or be connected to the heat conductive path 204a through a heat conductive member. Referring to fig. 6, in a direction perpendicular to the second surface 204, a thickness T1 of each heat dissipation block 50 is greater than a thickness T2 of each power switch element 40.

The heat dissipation block 50 is made of metal, such as copper. The heat dissipation area of each heat dissipation block 50 is larger than the heat dissipation area of each power switching element 40. A part of the thermal energy emitted from each of the power switching elements 40 is conducted to each of the heat dissipating blocks 50 through each of the heat conductive lines 204a and dissipated through the heat dissipating block 50, and another part of the thermal energy is dissipated by the power switching element 40 itself. The heat dissipation block 50 may also have a plurality of grooves to increase the heat dissipation area.

Since the power switching element 40 and the heat sink 50 are disposed on the second surface 204 of the circuit board 20 in parallel, the disadvantage of the conventional stacked power switching element and heat sink, which results in an increased total thickness, can be overcome, and therefore, the overall size of the brushless motor assembly, especially the length in the axial direction of the brushless motor assembly, can be reduced. In practice, the circuit board 20 may also be disposed at a side of the motor body 10, that is, at a radial periphery of the stator core 122, the first side 202 of the circuit board 20 faces the stator core 122, so that the length of the brushless motor assembly in the radial direction can be reduced.

Referring to fig. 4 and 5, in the present embodiment, the circuit board 20 has an inner ring portion 20a, an outer ring portion 20b and a side portion 20 c. In fig. 4 and 5, a dashed-dotted line is used as a boundary between the inner ring portion 20a and the outer ring portion 20 b. The inner ring portion 20a is provided with a through hole 201a, and the rotating shaft 14 and the bearing 32 pass through the through hole 201 a. The outer ring portion 20b surrounds the inner ring portion 20 a. The plurality of power switching elements 40 are located at the outer ring portion 20 b. The radiating fins 50 are mostly located at the outer ring portion 20b, and are only located at the inner ring portion 20a, but not limited thereto, and all the radiating fins 50 may be located at the outer ring portion 20 b. The side portion 20c is connected to the outer ring portion 20b, and an electrical connector 60 is provided on the side portion 20c for connection to an external control device. The plurality of electronic components includes a microcontroller 42 disposed on the second side 204 at the interface of the outer ring portion 20b and the side portion 20 c.

The plurality of electronic components include at least one driving component, and the driving component 44 is disposed on the second surface 204 of the circuit board 20 and located at the inner ring portion 20a, in this embodiment, the number of the at least one driving component 44 is plural. The first face 202 is also provided with a drive element 44 at the inner ring portion 20 a. The driving elements 44 are electrically connected to the power switching elements 40, respectively. The driving device 44 may be, for example, a gate driving device, for receiving a control signal sent by the microcontroller 42 to drive the gates of the plurality of power switch devices 40, so as to turn on or off the respective power switch devices 40. The thermal energy generated by each drive element 44 is less than the thermal energy generated by each power switching element 40.

The plurality of electronic components further include a plurality of hall sensing elements 46, the plurality of hall sensing elements 46 are disposed on the first surface 202 of the circuit board 20 and located on the inner ring portion 20a, and the plurality of hall sensing elements 46 are used for sensing the rotation of the rotor. The thermal energy generated by each hall sensing element 46 is less than that generated by each driving element 44 and each power switching element 40.

By disposing the power switching element 40 generating a large amount of heat energy on the outer ring portion 20b closer to the outside, the heat energy generated by the power switching element 40 is easily dissipated to the outside.

In order to protect the circuit board 20 and the electronic components, the brushless motor assembly of the present embodiment further includes a rear cover 70, the rear cover 70 is coupled to the rear insulating end plate 128 of the stator assembly 12 and has an inner side surface 702, the circuit board 20 is located between the inner side surface 702 of the rear cover 70 and the rear insulating end plate 128, and the inner side surface 702 faces the second surface 204 of the circuit board 20. The rear cover 70 may be made of metal to increase heat dissipation. The rear cover 70 has an outer peripheral portion 704, the outer peripheral portion 704 is located at the periphery of the outer peripheral portion 20b of the circuit board 20, and the outer peripheral portion 704 has a plurality of heat dissipation openings 704 a. The heat dissipation port 704a communicates the inside and the outside of the rear cover 70. The heat generated by the power switch device 40 can also be dissipated through the heat dissipation opening 704 a. The back cover 70 has a receiving groove 706, and the receiving groove 706 is recessed from the inner side 702 and is abutted by the bearing 32.

The circuit board 20 is connected to the stator coils 124 through a plurality of wires 80, and in the present embodiment, the number of the wires 80 is three, and each of the three wires corresponds to a corresponding stator coil 124 of three phases. One end of each of the plurality of electric wires 80 is soldered to the circuit board 20 and penetrates the stator core 122 through the second surface 204 to connect the stator coil 124, and a portion of each of the electric wires 80 is exposed to each of the heat dissipating ports 704 a. Therefore, the heat generated by the wires can be dissipated out through the heat dissipation opening 704 a.

A thermal pad 90 may be disposed between the rear cover 70 and the circuit board 20, and the thermal pad 90 is made of an electrically insulating material and has flexibility, such as a thermal silicone pad. The thermal pad 90 is disposed between the rear cover 70 and the circuit board 20, the thermal pad 90 has a first thermal conductive surface 902 and a second thermal conductive surface 904, the first thermal conductive surface 902 is connected to the inner side 702 of the rear cover 70, and the first thermal conductive surface 902 can directly contact and attach to the inner side 702 or attach to the inner side 702 through a thermal conductive member (thermal conductive paste or thermal conductive adhesive). The second heat-conducting surface 904 faces away from the first heat-conducting surface 902 and is connected to the heat-dissipating blocks 50, and the second heat-conducting surface 904 can directly contact and abut against the heat-dissipating block 50 or abut against the heat-dissipating block 50 through a heat-conducting member (heat-conducting paste or heat-conducting glue). The thermal pad 90 effectively transfers the heat generated from the heat slug 50 to the rear cover 70 to be dissipated by the rear cover 70. In this embodiment, the thermal pad 90 does not contact the power switch element 40 and other electronic components, so that the thermal pad 90 does not conduct heat to the power switch element 40 and other electronic components on the second surface 204 of the circuit board 20. In addition, a gap G is formed between the power switch element 40 and the thermal pad 90, and the gap G forms an air flow channel communicating with the outside, so that the power switch element 40 and other electronic components on the second surface 204 of the circuit board 20 can dissipate heat through the gap G.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications to the present invention as described and claimed should be included in the scope of the present invention.

Description of the reference numerals

[ invention ]

10: motor body

12: stator group

122: stator core

124: stator coil

126: front insulation end plate

128: rear insulation end plate

14: rotating shaft

20: circuit board

20 a: inner ring part

20 b: outer ring part

20 c: side part

201 a: perforation

202: first side

204: second surface

204 a: heat conducting circuit

30: front cover

32: bearing assembly

40: power switching element

42: micro-controller

44: driving element

46: hall sensing element

50: heat radiation block

60: electrical connector

70: back cover

702: inner side surface

704: outer peripheral edge portion

704 a: heat dissipation port

706: containing groove

80: electric wire

90: heat conducting pad

902: first heat conducting surface

904: second heat-conducting surface

G: gap

T1: thickness of

T2: thickness of