Outer rotor motor and power tool using the same

Abstract

The external rotor motor of the present invention includes a connecting base, a stator module, a rotating shaft, a support member, and a rotor module. The connecting base includes an end frame, a hollow tube, and a hollow cylinder. The end frame is connected to the hollow tube. The hollow tube has a channel. The hollow cylinder is connected to the end frame and forms an open space with the end frame and the hollow tube. The channel communicates with the open space. The stator module is connected to the hollow tube and is located within the open space. The rotating shaft is inserted into the channel. Both ends of the rotating shaft extend out of the hollow tube, with one end of the rotating shaft located outside the hollow cylinder. The support member is connected to the rotating shaft and is located within the channel. The rotor module is inserted into the open space and includes a connecting end cap. The connecting end cap is connected to the rotating shaft and is exposed outside the open space. The stator module is used to drive the rotor module to rotate relative to the connecting base. The hollow cylinder has multiple connecting portions.

Description

Technical Field

[0001] This invention relates to motors for power tools, and in particular to an external rotor motor and power tools using an external rotor motor. Background Technology

[0002] Chinese Patent Application Publication No. 116094276A discloses an external rotor motor and an electric tool thereof, in which blades are formed on the annular wall of the housing of the external rotor assembly to improve heat dissipation. However, since there are gaps or holes between the blades, foreign objects or dust can easily fall in, causing dust to accumulate on the surface of the magnet and affecting the motor's operating capacity.

[0003] Furthermore, Taiwan Patent No. I781070 discloses a pulse-type power tool transmission and trigger stop device, whose electric drive mechanism is an external rotor motor. Because the rotor of the external rotor motor is exposed and has a relatively long structure, in order to stably fix it inside the power tool's housing, this invention requires a coupling bearing to support the second extension of the external rotor to prevent severe vibration of the external rotor motor, thus increasing assembly difficulty and cost. Summary of the Invention

[0004] In view of the above deficiencies, the external rotor motor of the present invention can be easily assembled into power tools, and the connection between the tool head of the power tool and the external rotor motor can be simplified.

[0005] To achieve the above objectives, the external rotor motor of the present invention includes a connecting base, a stator module, a rotating shaft, a support member, and a rotor module. The connecting base includes an end frame, a hollow tube, and a hollow cylinder. The end frame is connected to the hollow tube. The hollow tube has a channel. The hollow cylinder is connected to the end frame and forms an open space with the end frame and the hollow tube. The channel communicates with the open space. The stator module is connected to the hollow tube and is located within the open space. The rotating shaft is inserted into the channel. Both ends of the rotating shaft extend out of the hollow tube, with one end of the rotating shaft located outside the hollow cylinder. The support member is connected to the rotating shaft and is located within the channel. The rotor module is inserted into the open space and includes a connecting end cap. The connecting end cap is connected to the rotating shaft and is exposed outside the open space. The stator module is used to drive the rotor module to rotate relative to the connecting base. The hollow cylinder has multiple connecting portions.

[0006] Thus, the external rotor motor of the present invention provides external connection through the joint of the hollow cylindrical body of the connecting seat, making the assembly of the external rotor motor simpler. In addition, the hollow cylindrical body can increase the heat dissipation area and prevent foreign objects from falling into the rotor module, thereby improving the reliability of the external rotor motor.

[0007] To achieve the above objectives, the power tool of the present invention includes a housing, a tool head, a fan, and the aforementioned external rotor motor. The housing includes multiple positioning portions. The tool head and fan are mounted inside the housing. The external rotor motor is mounted inside the housing and located between the tool head and the fan. The positioning portions are engaged with a portion of the hollow cylindrical body. The tool head is connected to the rotor module.

[0008] In this way, the external rotor motor can be directly connected to the positioning part of the housing, which simplifies the assembly complexity and reduces the number of parts used, thereby improving assembly efficiency.

[0009] Detailed construction, features, assembly, and usage of the external rotor motor and power tools using the external rotor motor provided by this invention will be described in the following detailed description of embodiments. However, those skilled in the art will understand that such detailed descriptions and the specific embodiments listed for implementing this invention are merely illustrative and not intended to limit the scope of this patent application. Attached Figure Description

[0010] Figure 1 and Figure 2 These are perspective views of the external rotor motor of the present invention from different angles.

[0011] Figure 3 It is for reference. Figure 2 An exploded view of the external rotor motor of the present invention.

[0012] Figure 4 It is for reference. Figure 3 A cross-sectional view through the joint of the hollow cylinder.

[0013] Figure 5 It is for reference. Figure 1 A cross-sectional view through the joint of the hollow cylinder.

[0014] Figure 6 This is an exploded view of the adapter of the rotor module of the external rotor motor of the present invention.

[0015] Figure 7 yes Figure 6 A perspective view of the external rotor motor of the present invention.

[0016] Figure 8 It is an application Figure 7 A schematic diagram of the electric tool with the external rotor motor of the present invention.

[0017] Explanation of reference numerals in the attached figures:

[0018] 100: External rotor motor

[0019] 10: Connector

[0020] 11: End frame

[0021] 111: Heat dissipation vent

[0022] 13: Hollow tube body

[0023] 131: Channel

[0024] 133: Free End

[0025] 135: Straight segment

[0026] 137: Expansion Segment

[0027] 15: Hollow cylindrical body

[0028] 151: Groove

[0029] 153: Joint

[0030] 155: Free End

[0031] 157: Outer side

[0032] 159:Inner wall surface

[0033] 17: Open Space

[0034] 20: Stator Module

[0035] 21: Stator core

[0036] 30: Shaft

[0037] 40: Support component

[0038] 41: Bearing

[0039] 43: Fastening unit

[0040] 50: Rotor Module

[0041] 51: End cap

[0042] 511: Ventilation opening

[0043] 513: Screw hole

[0044] 53: Magnet

[0045] 55: Hollow Sleeve

[0046] 57: Rotor bearing

[0047] 59: Adapter

[0048] 591: Disk Body

[0049] 592: Screw hole

[0050] 593: Meshing part

[0051] 595: Adapter

[0052] 597: Bolt

[0053] 599: Perforation

[0054] 600: Power Tools

[0055] 61: Shell

[0056] 611: Positioning Department

[0057] 63: Tool Head

[0058] 65: Fan Detailed Implementation

[0059] like Figures 1 to 3 As shown, the external rotor motor 100 of the present invention includes a connecting seat 10, a stator module 20, a rotating shaft 30, a support member 40, and a rotor module 50.

[0060] The connecting seat 10 includes an end frame 11, a hollow tube 13, and a hollow cylindrical body 15. The end frame 11 is connected to the hollow tube 13. The hollow tube 13 has a channel 131. The hollow cylindrical body 15 is connected to the end frame 11 and forms an open space 17 with the end frame 11 and the hollow tube 13. In this embodiment, the end frame 11 is located at one end of the hollow cylindrical body 15; in other embodiments, the end frame 11 may also be located inside the hollow cylindrical body 15.

[0061] The end frame 11 has multiple heat dissipation vents 111 communicating with the open space 17. The hollow cylinder 15 has multiple grooves 151 and four joints 153. The grooves 151 extend from a free end 155 of the hollow cylinder 15 to the end frame 11 and are located on the outer side 157 of the hollow cylinder 15 to increase the heat conduction area. The free end 155 and the end frame 11 are located on opposite sides of the hollow cylinder 15. The inner wall surface 159 of the hollow cylinder 15 is a complete arc surface, that is, without any openings, to define the extent of the open space 17 and to prevent external dust or foreign objects from falling in from the outer side 157.

[0062] In this embodiment, the connecting seat 10 is a one-piece metal (e.g., aluminum or aluminum alloy) structure to provide superior thermal conductivity and structural strength. The groove 151 connects to the heat dissipation port 111. The connecting portions 153 are in pairs and symmetrically positioned; two are shown in the figure, while the other two are positioned opposite each other. The connecting portion 153 is a recess, that is, a structure recessed from the outer side 157 of the hollow cylinder 15, so that the connecting portion 153 communicates with the adjacent groove 151. In other embodiments, the connecting portion 153 may also be other structures, such as protrusions or other structures that can be fixed and positioned, and the number of connecting portions 153 may be more or less.

[0063] The stator module 20 is fixedly connected to the hollow tube 13 and is located within the open space 17. The stator module 20 includes a stator core 21 and stator windings (not shown in the figure) wound on the stator core 21.

[0064] The rotating shaft 30 is inserted into the channel 131. The rotating shaft 30 is a long straight metal rod with its two ends extending out of the hollow tube 13. The two ends of the rotating shaft 30 are located outside the hollow cylinder 15.

[0065] The support member 40 is connected to the rotating shaft 30 and is located within the channel 131. In this embodiment, the support member 40 includes a bearing 41 and a fastening unit 43. The bearing 41 is sleeved on the rotating shaft 30, and the fastening unit 43 fastens the rotating shaft 41 to position the bearing 41 and prevent the bearing 41 from disengaging from the rotating shaft 30.

[0066] The rotor module 50 is inserted into the open space 17 and includes a coupling end cap 51. The coupling end cap 51 connects to the rotating shaft 30 and is exposed outside the open space 17. The coupling end cap 51 has eight vents 511 and four screw holes 513. The vents 511 communicate with the open space 17. The screw holes 513 are used to screw on an adapter or tool head; the adapter is used to engage the tool head, and subsequently... Figure 6 illustrate.

[0067] like Figure 4 As shown, the hollow cylindrical body 15 exhibits a symmetrical structure at the joint 153. The hollow cylindrical body 15 and the end frame 11 are approximately perpendicular. The hollow tube 13 is shorter than the hollow cylindrical body 15; that is, the free end 133 of the hollow tube 13 is recessed within the open space 17. Furthermore, the channel 131 of the hollow tube 13 has a continuous straight section 135 and an expansion section 137, the straight section 135 extending from the free end 133 to the expansion section 137. The expansion section 137 is used to accommodate the support member 40.

[0068] like Figure 5 As shown, the rotor module 50 also includes multiple magnets 53, a hollow sleeve 55, and a rotor bearing 57. The hollow sleeve 55 is connected to the connecting end cap 51 and is located within the open space 17, spaced apart between the hollow cylinder body 15 and the stator module 20. The multiple magnets 53 are connected to the hollow sleeve 55 and face the stator module 20 at intervals. The multiple magnets 53 are located within the hollow sleeve 55 and are arranged at intervals, with the magnetic poles of adjacent magnets arranged oppositely. The rotor bearing 57 connects the rotating shaft 30 and the stator module 20 and is located between the connecting end cap 51 and the hollow tube body 13. Thus, the rotor bearing 57 and the bearing 41 of the support member 40 can provide two support points to stabilize the rotating shaft 30, allowing the rotor module 50 to rotate stably and avoid vibration.

[0069] Thus, the stator module 20 of the external rotor motor 100 of the present invention is fixed to the hollow tube 13 of the connecting seat 10 and does not rotate. After the stator module 20 is energized, it generates a magnetic field that interacts with the magnetic field of the magnet 53 of the rotor module 50 to generate torque, thereby causing the rotor module 50 to rotate.

[0070] like Figures 6 to 7 As shown, the rotor module 50 also includes an adapter 59. The adapter 59 is connected to the engagement end cover 51 and includes a disc 591, multiple meshing parts 593, an adapter 595, and four bolts 597. The disc 591 is located on the engagement end cover 51.

[0071] The engaging portion 593 is formed on the disc body 591 and engages with the limiting portion of the connecting end cap 51. In this embodiment, the engaging portion 593 is a tooth protruding from the right side (figure) of the disc body 591, and the limiting portion of the connecting end cap 51 is a portion of the vent 511, so that the tooth is substantially engaged within the vent 511 (e.g., Figure 7 As shown in the figure, the teeth do not completely cover the vents to preserve the heat dissipation channels.

[0072] In other embodiments, the disc 591 and the meshing portion 593 have a through hole 599 communicating with the ventilation port 511 for heat dissipation. The number of meshing portions 593 and limiting portions can be increased or decreased simultaneously, and there can be as few as one. The meshing portions 593 and limiting portions are mainly used for mutual meshing to enhance the structural stability during rotor rotation. Therefore, the meshing portions 593 and limiting portions can be other forms of structures that can mesh with each other, and the limiting portion can also be other structures combined with the end cover 51, not limited to the heat dissipation hole 511.

[0073] The adapter 595 protrudes from the disc body 591 and is located on the left side of the disc body 591 (in the figure). The adapter 595 and the engaging part 593 are opposite to each other on the disc body 591. In this embodiment, the adapter 593 is a hollow hexagonal head, which faces the rotating shaft 30 to connect to the tool head of a power tool. The bolt 597 passes through the screw hole 592 of the disc body 591 and screws into the screw hole 513 of the connecting end cover 51 to lock the adapter seat 59 onto the connecting end cover 51.

[0074] like Figure 8As shown, the power tool 600 of the present invention includes a housing 61, a tool head 63, a fan 65, and the aforementioned external rotor motor 100. The housing 61 includes multiple positioning portions 611, which are located inside the housing 61 and are protruding structures to engage with the recessed structure of the connecting portion 153 for positioning. To clearly show the interior of the housing 61, one side of the outer shell is omitted in the figure. The external rotor motor 100 is installed inside the housing 61 and is located between the tool head 63 and the fan 65. The connecting portion 153 of the hollow cylinder 15 engages with the positioning portions 611 to securely position the external rotor motor 100, making assembly simpler than in the prior art. The tool head 63 connects to the adapter 595 of the adapter base 59. The tool head 63 is a mechanism for transmitting and outputting torque through the rotational power of the rotary motor 100. Applications of the tool head 63 include, for example, hexagonal quick-release connectors, screwdriver bits, drill bits, wrenches, and other tool connectors.

[0075] Thus, since the adapter 59 of the rotor module 50 of the external rotor motor can engage with the limiting part of the connecting end cover 51 through the meshing part 593, a more stable structure is provided to prevent the bolt 597 from loosening due to rotational torque. In other embodiments, if the output torque is small, the tool head 63 can also be directly connected to the connecting end cover 51 of the rotor module or the meshing part 593 of the adapter 59 can be omitted.

[0076] In other embodiments, the external rotor motor 100 of the present invention can also be applied to other environments requiring rotational torque, and is not limited to power tools.

[0077] The methods and constituent elements disclosed in the foregoing embodiments of the present invention are merely illustrative examples and are not intended to limit the patent scope of the present invention. Any simple structural modifications or changes made without departing from the spirit of the present invention, or any substitutions with other equivalent elements, should still fall within the scope of the patent application of the present invention.

Claims

1. An external rotor motor, comprising: A connecting seat includes an end frame, a hollow tube body and a hollow cylinder body. The end frame is connected to the hollow tube body. The hollow tube body has a channel. The hollow cylinder body is connected to the end frame and forms an open space with the end frame and the hollow tube body. The channel communicates with the open space. A certain sub-module is connected to the hollow tube body and is located within the open space; A rotating shaft is inserted into the channel, with both ends of the rotating shaft extending out of the hollow tube body, and one of the two ends of the rotating shaft located outside the hollow tube body; A support member, connected to the pivot, and located within the channel; and A rotor module is inserted into the open space and includes a connecting end cap connected to the rotating shaft and exposed outside the open space. The stator module is used to drive the rotor module to rotate relative to the connecting seat. The hollow cylinder has multiple connecting parts.

2. The external rotor motor as described in claim 1, wherein, The end frame has multiple heat dissipation vents that connect to the open space. The hollow cylinder has multiple grooves that extend from a free end of the hollow cylinder to the end frame and are located on the outside of the hollow cylinder. The free end and the end frame are located on opposite sides of the hollow cylinder.

3. The external rotor rotary motor as described in claim 2, wherein, The multiple grooves connect to the multiple heat dissipation ports.

4. The external rotor rotary motor as described in claim 2, wherein, Each of the plurality of joints is a recess and communicates with the adjacent plurality of grooves.

5. The external rotor motor as described in claim 2, wherein, The inner wall of the hollow cylinder is a complete arc surface to define the open space.

6. The external rotor motor as described in claim 1, wherein, The connecting end cap includes a limiting part, and the rotor module includes an adapter seat connected to the connecting end cap. The adapter seat also includes a disc body, an engagement part, and an adapter. The engagement part is formed on the disc body and engages with the limiting part. The adapter protrudes from the disc body and faces away from the engagement part.

7. The external rotor motor as described in claim 6, wherein, The end cap has multiple vents that connect to the open space, the limiting part is one of the multiple vents, and the engaging part has a through hole that connects to the vent.

8. The external rotor motor as described in claim 1, wherein, The rotor module also includes multiple magnets, a hollow sleeve and a rotor bearing. The hollow sleeve is connected to the connecting end cap and is located in the open space, and is spaced between the hollow cylinder body and the stator module. The multiple magnets are connected to the hollow sleeve and face the stator module at intervals. The rotor bearing is connected to the rotating shaft and the stator module, and is located between the connecting end cap and the hollow tube body.

9. The external rotor rotary motor as described in claim 1, wherein, The support is located near the end frame of the connector.

10. A power tool comprising a housing, a tool head, a fan, and an external rotor motor as described in any one of claims 1 to 9, wherein the housing includes a plurality of positioning portions, the tool head and the fan are mounted inside the housing, the external rotor motor is mounted inside the housing and located between the tool head and the fan, the plurality of connecting portions of the hollow cylindrical body are connected to the plurality of positioning portions, and the tool head is connected to the rotor module.

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