Short high-torque direct-current brush micro motor for electric tool

Abstract

The utility model belongs to the technical field of motors, and discloses a short high-torque direct-current brush micro motor for an electric tool, which comprises a motor shell, a stator module and a rotor module, and the stator module and the rotor module are arranged in the motor shell. The motor further comprises a power connection module, the power connection module comprises a power connection supporting shell cover, one end of the motor shell is provided with a shell rear port matched with the power connection supporting shell cover, and the power connection supporting shell cover is arranged in the shell rear port. And the rotor supporting shell cover is rotatably connected with the rotating shaft of the rotor module, and the rotor supporting shell cover is detachably connected with the rear port of the shell, so that the power connection supporting shell cover is clamped in the rear port of the shell. According to the utility model, the power connection supporting shell cover and the rotor supporting shell cover are integrally installed in the shell rear port of the motor shell, and the power connection supporting shell cover and the rotor supporting shell cover can be made thinner, so that the length of the whole motor in the axial direction is reduced, and the motor is suitable for being used by short electric tools.

Description

Technical Field

[0001] The utility model relates to a short and high-torque DC brush micro motor for power tools, belonging to the technical field of electric motors. Background Art

[0002] A DC brush micro motor is a rotating motor with a built-in brush device. It can convert DC electrical energy into mechanical energy, and its working principle is based on electromagnetic induction and electromagnetic force. When a fixed magnetic field is generated by the stator, the rotor winding is excited to generate a magnetic field. The magnetic poles of the rotor magnetic field are opposite to those of the stator magnetic field and attract each other, thus generating a rotating torque to drive the rotor to rotate. During the rotation process, the rotor continuously energizes the winding in different sequences, and the commutation of the current is achieved through the commutator to ensure that the magnetic poles generated by the rotor do not overlap with those generated by the stator, thereby realizing continuous rotation.

[0003] In the power tool industry, for the demand of high-torque and high-speed DC brush motors, the industry generally tends to choose two products: the 755 motor with an outer diameter of 42.4 mm and a length of 60 mm; and the 775 motor with the same outer diameter of 42.4 mm and a length of 66 mm. After assembling the magnetic shielding ring, the maximum outer diameter of these two motors can increase to 46.5 mm. However, considering that the length of both of these two motors is at least 60 mm, this size limitation affects the overall length design of power tools to a certain extent, especially restricting the research and development of short power tools. Content of the Utility Model

[0004] Aiming at the deficiencies of the above-mentioned prior art, the purpose of the utility model is to provide a short and high-torque DC brush micro motor for power tools. By integrally installing the power connection support cover into the motor housing while the rotor support cover is connected to the motor housing, the length of the entire motor in the axial direction can be reduced.

[0005] To achieve the above purpose, the utility model provides a short and high-torque DC brush micro motor for power tools, including a motor housing, a stator module and a rotor module arranged in the motor housing;

[0006] It further includes a power connection module. The power connection module includes a power connection support cover. One end of the motor housing is provided with a housing rear port adapted to the power connection support cover, and the power connection support cover is arranged in the housing rear port;

[0007] A rotor support cover, which is rotatably connected to the rotating shaft of the rotor module and is detachably connected to the housing rear port, so that the power connection support cover is clamped in the housing rear port.

[0008] Further, as a more preferred embodiment of the present utility model, the rotor module includes: a rotor core member disposed on a rotating shaft, and a conductive wire body wound around the rotor core member; the conductive wire body at at least one end of the rotor core member is recessed or flush with the end face of the rotor core member;

[0009] A heat dissipation fan blade disposed on the rotating shaft, and one end face of the rotor core member is connected to one end face of the rotor core member.

[0010] Further, as a more preferred embodiment of the present utility model, the rotor module further includes a commutator disposed on the rotating shaft;

[0011] The power connection module further includes a carbon brush member and a power connection terminal disposed in the power connection support housing cover. The carbon brush members are respectively connected to both sides of the commutator, and the carbon brush members are respectively connected to the corresponding power connection terminals through brush arms; the power connection terminals respectively extend out of the other end face of the power connection support housing cover;

[0012] At least two protruding portions are provided on the outer side of the power connection support housing cover, and a clamping groove adapted to the protruding portions is provided on the side wall of the rear port of the housing, and the protruding portions are snapped into the clamping grooves.

[0013] Further, as a more preferred embodiment of the present utility model, the surface of the protruding portion is flush with the end face of the rear port of the housing, the rotor support housing cover is provided with a clamping groove adapted to the protruding portion, the rotor support housing cover is flush with the rear port of the housing, and the clamping groove is snapped into the protruding portion.

[0014] Further, as a more preferred embodiment of the present utility model, a limiting protrusion is provided at the position where the power connection terminal extends out of the power connection support housing cover, the rotor support housing cover is provided with a clamping groove adapted to the limiting protrusion, the clamping groove is snapped into the limiting protrusion, and the power connection terminal passes through the clamping groove and extends out of the motor housing.

[0015] Further, as a more preferred embodiment of the present utility model, the outer diameter of the rotor core member is 32 mm, and the number of slots of the rotor core member is 7 slots or 10 slots.

[0016] Further, as a more preferred embodiment of the present utility model, the stator module includes a permanent magnet, and the thickness of the permanent magnet is 5 mm; the outer diameter of the motor housing is 47 mm, and the wall thickness of the motor housing is 1.6 mm.

[0017] Further, as a more preferred embodiment of the utility model, a first through slot is provided in the middle of the rotor support shell cover, a second through slot corresponding to the position of the first through slot is provided at the other end of the motor housing, the first through slot and the second through slot are respectively provided with bearings adapted to the rotating shaft, and a through hole for the rotating shaft to pass through is provided in the middle of the power connection support shell cover.

[0018] Further, as a more preferred embodiment of the present invention, the rotor support shell cover is partially provided with heat dissipation exhaust holes.

[0019] Further, as a more preferred embodiment of the present invention, exhaust notches are evenly distributed on the motor housing at positions corresponding to the heat dissipation blades.

[0020] Compared with the prior art, the beneficial effects are:

[0021] 1. The power connection support shell cover and the rotor support shell cover adopted by the utility model are integrated and installed into the rear port of the motor housing. The power connection support shell cover is used for connecting the rotor module to electricity. The rotor support shell cover is used to fix the power connection support shell cover in the rear port of the housing, and is also used to be rotatably connected to one end of the rotating shaft and provide support for it. Compared with the traditional external rotor support shell cover, the power connection support shell cover and the rotor support shell cover of the utility model can be made thinner, which can further reduce the length of the entire motor in the axial direction, and is suitable for the use of short power tools.

[0022] 2. The conductive wire at at least one end of the rotor core member of the utility model is recessed or flush with the end face of the rotor core member. When the recessed or flush end face is connected with the end face of the heat dissipation fan blade, the length of the entire motor in the axial direction can be further reduced, making it suitable for use with short electric tools.

[0023] 3. In the utility model, at least two protrusions are arranged on the outer side of the electrical support shell cover, and the protrusions are inserted into the slots. One end face of the protrusion in the radial direction of the motor housing can be flush with or hang on the slot to avoid squeezing the commutator; and one end face of the protrusion in the axial direction of the motor housing can also be flush with the port plane of the rear port of the housing. At the same time, the rotor support shell cover is provided with a snap-in groove matched with the protrusion, and the snap-in groove corresponds to the protrusion. The rotor support shell cover can be arranged in the rear port of the housing, and can be clamped on the protrusion of the electrical support shell cover when it is detachably connected to the motor housing, and the electrical support shell cover is fixed in the rear port of the housing. Moreover, the end face of the rotor support shell cover can also keep the rear port of the housing flush with or slightly concave with the end face of the rear port of the housing. In particular, a limiting protrusion is provided at the position where the power terminal extends from the rotor support shell cover. The limiting protrusion can not only support and fix the power terminal, but also match the positioning groove of the rotor support shell cover for positioning and installation, and can further fix and limit the power support shell cover.

[0024] 4. The present utility model optimizes the dimensions of the motor housing and the rotor core. The increase in the outer diameter of the motor housing and the shortening of the radial length enable it to be more suitable for short electric tools while maintaining a constant rotational speed and torque. The outer diameter of the rotor core can be expanded from the original approximately 28 mm to 32 mm, and the number of slots in the rotor core can be adjusted from 5 slots to 7 slots or 10 slots, further enhancing the torque and durability of the motor. At the same time, the outer diameter of the motor housing can be correspondingly expanded from 42.4 mm to 47 mm, and the permanent magnet can also be increased synchronously; the thickness of the housing can be increased from the original 1.2 mm to 1.6 mm. The increase in thickness effectively improves the magnetic flux in the inner cavity of the permanent magnet, thereby indirectly improving the performance of the permanent magnet, making the performance of the same permanent magnet in the housing more advantageous than that of existing motors. In summary, the length of the motor can be reduced from 60 mm to 53 mm, and under the same rotational speed conditions, it can still maintain the same or higher load torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a short and high-torque DC brushed micro-motor in the embodiment.

[0026] Figure 2 It is an expanded schematic structural diagram of the power connection support cover and the rotor support cover in the embodiment.

[0027] Figure 3 It is a schematic structural diagram of the rotor module in the embodiment.

[0028] Figure 4 It is a schematic structural diagram of the motor housing in the embodiment.

[0029] REFERENCE NUMERALS:

[0030] 1 - Motor housing, 11 - Rear port of the housing, 12 - Bendable fixing part, 13 - Card slot, 14 - Second through slot, 15 - Exhaust slot; 2 - Stator module; 3 - Rotor module, 31 - Rotating shaft, 32 - Rotor core, 33 - Conductive wire body, 34 - Cooling fan blade, 35 - Commutator, 36 - Oil stop gasket, 37 - Adjusting gasket, 38 - Thrust washer; 4 - Power connection module, 41 - Power connection support cover, 411 - Carbon brush part, 412 - Power connection terminal, 413 - Brush arm, 414 - Protrusion, 415 - Limit protrusion, 42 - Rotor support cover, 421 - Buckle slot, 422 - Clamping slot, 423 - Positioning slot, 424 - First through slot, 425 - Bearing, 426 - Cooling exhaust hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To enable those skilled in the art to better understand the technical solutions in this application, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by this application.

[0032] It should be noted that when an element is referred to as "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly disposed on the other component; when a component is referred to as "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component.

[0033] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0034] 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 one or more of such features. In the description of this application, the meanings of "multiple" and "several" are two or more, unless otherwise specifically defined.

[0035] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions under which this application can be implemented. Therefore, they do not have a technical essence. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that this application can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in this application.

[0036] Embodiment

[0037] The purpose of this embodiment is to facilitate the solution to the problem that when a motor is applied to a power tool, the general length of the motor is too long, which to a certain extent affects the overall length design of the power tool, especially the research and development of short power tools.

[0038] Based on the above problems, this embodiment provides a short and high-torque DC brushed micro-motor for power tools. The power connection support cover 41 and the rotor support cover 42 are integrally installed into the rear port 11 of the motor housing 1. The power connection support cover 41 is used for power connection of the rotor module 3, and the rotor support cover 42 is used to fixedly install the power connection support cover 41 in the rear port 11 of the housing, and is also used for rotatably connecting with one end of the rotating shaft 31 and providing support for it. Compared with the traditional external rotor support cover 42, the power connection support cover 41 and the rotor support cover 42 of the present utility model can be made thinner, and can further reduce the length of the entire motor in the axial direction, adapting to the use of short power tools.

[0039] Referring to Figures 1-4 As shown, specifically, a short and high-torque DC brushed micro-motor for power tools includes a motor housing 1, a stator module 2 and a rotor module 3 arranged in the motor housing 1;

[0040] It further includes a power connection module 4. The power connection module 4 includes a power connection support cover 41. One end of the motor housing 1 is provided with a rear port 11 of the housing adapted to the power connection support cover 41, and the power connection support cover 41 is arranged in the rear port 11 of the housing;

[0041] A rotor support cover 42, the rotor support cover 42 is rotatably connected to the rotating shaft 31 of the rotor module 3, and the rotor support cover 42 is detachably connected to the rear port 11 of the housing so that the power connection support cover 41 is clamped in the rear port 11 of the housing.

[0042] In this embodiment, the detachable connection method between the rotor support cover 42 and the rear port 11 of the housing can be that a plurality of bendable fixing parts 12 are provided on the outer wall of the rear port 11 of the housing, and the rotor support cover 42 is evenly provided with buckle grooves 421 adapted to the bendable fixing parts 12; when the rotor support cover 42 is installed on the rear port 11 of the housing, the bendable fixing parts 12 are bent and bitten into the buckle grooves 421 of the rotor support cover 42, and the rotor support cover 42 is pressed against the power connection support cover 41. This connection method is more concise and effective. In addition, some embodiments can also adopt welding and bolt connection. The power connection support cover 41 in this embodiment can be in a ring shape, and one end face is flush with the end face after installing the carbon brush part 411.

[0043] Referring to Figure 3As shown, specifically, the rotor module 3 includes: a rotor core member 32 disposed on a rotating shaft 31, and a conductive wire body 33 wound around the rotor core member 32; the conductive wire body 33 at at least one end of the rotor core member 32 is recessed or flush with the end face of the rotor core member 32; a cooling fan blade 34 disposed on the rotating shaft 31, and one end face of the rotor core member 32 is connected to one end face of the rotor core member 32. In this embodiment, the end face of the rotor core member 32 in contact with the cooling fan blade 34 is preferably such that the conductive wire body 33 is flush with the end face of the rotor core member 32, or the conductive wire body 33 can be recessed from the end face of the rotor core member 32; and the conductive wire body 33 on the other end face of the rotor core member 32 in this embodiment can be wound to protrude from the end face of the rotor core member 32 to further increase the amount of the conductive wire body.

[0044] As shown in FIG. 3, specifically, the rotor module 3 further includes a commutator 35 disposed on the rotating shaft 31; the power connection module 4 further includes a carbon brush member 411 and a power connection terminal 412 disposed in a power connection support housing cover 41, carbon brush members 411 are respectively connected to two sides of the commutator 35, and the carbon brush members 411 are respectively connected to corresponding power connection terminals 412 through brush arms 413; the power connection terminals 412 respectively extend out of the other end face of the power connection support housing cover 41; at least two protrusions 414 are disposed on the outer side of the power connection support housing cover 41, and a clamping groove 13 adapted to the protrusions 414 is disposed on the side wall of the rear port 11 of the housing, and the protrusions 414 are snapped into the clamping groove 13.

[0045] Refer to Figure 1 、 2 As shown in FIGS. 4, specifically, the surface of the protrusion 414 is flush with the end face of the rear port 11 of the housing, the rotor support housing cover 42 is provided with a clamping groove 422 adapted to the protrusion 414, the rotor support housing cover 42 is flush with the rear port 11 of the housing, and the clamping groove 422 is snapped onto the protrusion 414.

[0046] Refer to Figure 1 and 2As shown, specifically, the power support shell cover 41 is provided with a limiting protrusion 415 at the position where the power terminal 412 extends, and the rotor support shell cover 42 is provided with a locking groove 423 adapted to the limiting protrusion 415, the locking groove 423 is locked in the limiting protrusion 415, and the power terminal 412 extends out of the motor housing 1 through the locking groove 423. By snapping the protrusion 414 into the slot 13, one end face of the protrusion 414 in the radial direction of the motor housing 1 can be flush or hung on the slot 13 to avoid squeezing the commutator 35; and one end face of the protrusion 414 in the radial direction of the motor housing 1 can also be flush with the port plane of the housing rear port 11, and at the same time, the rotor support shell cover 42 is provided with a snap-in groove 422 adapted to the protrusion 414, and the snap-in groove 422 corresponds to the protrusion 414. The sub-support shell cover can be set in the housing rear port 11, and when it is detachably connected to the motor housing 1, it can be clamped on the protrusion 414 of the power support shell cover 41 to fix the power support shell cover 41 in the housing rear port 11, and the end face of the rotor support shell cover 42 can also keep the housing rear port 11 flush or slightly concave with the end face of the housing rear port 11. In particular, the rotor support shell cover 42 is provided with a limiting protrusion 415 at the position where the power terminal 412 extends. The limiting protrusion 415 can not only support and fix the power terminal 412, but also match the positioning groove 423 of the rotor support shell cover 42 for positioning and installation, and can also further fix and limit the power support shell cover 41.

[0047] In this embodiment, the outer diameter of the rotor core member 32 can be expanded from the original approximately 28 mm to 32 mm, and the number of slots of the rotor core member 32 can be adjusted from 5 slots to 7 slots or 10 slots, further enhancing the torque and durability of the motor.

[0048] In this embodiment, the stator module 2 includes a permanent magnet, and the outer diameter of the motor housing 1 can be correspondingly expanded from 42.4 mm to 47 mm, and the permanent magnet can also be increased synchronously; the thickness of the housing can also be increased from the original 1.2 mm to 1.6 mm. The increase in thickness effectively increases the magnetic flux in the inner cavity of the permanent magnet, thereby indirectly improving the performance of the permanent magnet, making the performance of the same permanent magnet in the housing more advantageous than that of the existing motor. In summary, the length of the motor can be reduced from 60 mm to 53 mm, and under the same speed conditions, the same or higher load torque can still be maintained.

[0049] Reference Figure 1 and 2 As shown, in this embodiment, a first through slot 424 is provided in the middle of the rotor support shell cover 42, and a second through slot 14 corresponding to the position of the first through slot 424 is provided at the other end of the motor housing 1. The first through slot 424 and the second through slot are respectively provided with bearings 425 adapted to the rotating shaft 31, and a through hole for the rotating shaft 31 to pass through is provided in the middle of the power support shell cover 41.

[0050] Referring to Figure 1 and 2 As shown, in this embodiment, the rotor support housing cover 42 has heat dissipation and exhaust holes 426 locally.

[0051] Referring to Figure 4 As shown, in this embodiment, exhaust slots 15 are evenly arranged at the positions of the motor housing 1 corresponding to the heat dissipation fan blades 34. It should be added that an oil stop gasket 36 and an adjusting gasket 37 are installed at one end of the rotating shaft 31 at the commutator 35, and a thrust gasket 38 is installed at the other end of the rotating shaft 31.

[0052] After the short-stroke high-torque DC brushed micro-motor of this embodiment is connected to a DC power supply through the power connection terminals 412, the direct current passes through the two power connection terminals 412, the brush arm 413 and the carbon brush assembly 411, flows through the commutator 35 and enters the wire body 33 to form a loop, thereby generating an electromagnetic field. The energized armature winding rotates in the permanent magnetic field of the stator module 2 due to the action of the Lorentz force.

[0053] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A short-type high-torque DC brushed micro motor for electric tools, comprising a motor housing and a stator module and a rotor module arranged in the motor housing; characterized in that: It also includes a power connection module, the power connection module includes a power connection support shell cover, one end of the motor housing is provided with a housing rear port adapted to the power connection support shell cover, and the power connection support shell cover is arranged in the housing rear port; The rotor support shell cover is rotatably connected to the rotating shaft of the rotor module, and the rotor support shell cover is detachably connected to the rear port of the shell so that the power support shell cover is clamped in the rear port of the shell.

2. The short-length high-torque DC brushed micro motor according to claim 1 is characterized in that: The rotor module comprises: a rotor core member arranged on a rotating shaft, wherein a conductive wire is wound around the rotor core member; the conductive wire at at least one end of the rotor core member is concave or flush with an end surface of the rotor core member; A heat dissipation blade is arranged on the rotating shaft, and one end surface of the rotor core member is connected to one end surface of the rotor core member.

3. The short-length high-torque DC brushed micro motor according to claim 1 is characterized in that: The rotor module also includes a commutator disposed on the rotating shaft; The power connection module also includes a carbon brush member and a power connection terminal arranged in the power connection support shell cover, the two sides of the commutator are respectively connected to the carbon brush members, and the carbon brush members are respectively connected to the corresponding power connection terminals through brush arms; the power connection terminals respectively extend out of the other end surface of the power connection support shell cover; At least two protrusions are arranged on the outer side of the power connection support shell cover, and a slot matching the protrusions is arranged on the side wall of the rear port of the shell, and the protrusions are inserted into the slots.

4. The short-length high-torque DC brushed micro motor according to claim 3 is characterized in that: The surface of the protrusion is flush with the end surface of the rear port of the shell, and the rotor support shell cover is provided with a clamping groove adapted to the protrusion. The rotor support shell cover is flush with the rear port of the shell, and the clamping groove is clamped into the protrusion.

5. The short-length high-torque DC brushed micro motor according to claim 4 is characterized in that: The power connection support shell cover is provided with a limiting protrusion at the position where the power connection terminal extends, and the rotor support shell cover is provided with a locking groove adapted to the limiting protrusion, the locking groove is locked in the limiting protrusion, and the power connection terminal extends out of the motor housing through the locking groove.

6. The short-length high-torque DC brushed micro motor according to claim 2 is characterized in that: The outer diameter of the rotor core is 32 mm, and the number of slots of the rotor core is 7 or 10.

7. The short-length high-torque DC brushed micro motor according to claim 6, characterized in that: The stator module includes a permanent magnet, and the thickness of the permanent magnet is 5 mm; the outer diameter of the motor housing is 47 mm, and the wall thickness of the motor housing is 1.6 mm.

8. The short-length high-torque DC brushed micro motor according to claim 1, characterized in that: A first through slot is arranged in the middle of the rotor support shell cover, a second through slot corresponding to the position of the first through slot is arranged at the other end of the motor housing, bearings adapted to the rotating shaft are arranged in the first through slot and the second through slot respectively, and a through hole for the rotating shaft to pass through is arranged in the middle of the power connection support shell cover.

9. The short-length high-torque DC brushed micro motor according to claim 2, characterized in that: The rotor support shell cover is partially provided with heat dissipation exhaust holes.

10. The short-length high-torque DC brushed micro motor according to claim 2, characterized in that: The motor housing is evenly provided with exhaust notches at positions corresponding to the heat dissipation blades.

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