Driving device and brushless motor

Abstract

The invention relates to a driving device and a brushless motor thereof. The stator of the brushless motor comprises a stator core and a motor shell. The motor shell comprises a first end cover, a first shell section, a connection section and a second shell section; the two ends of the first shell section are connected with the first end cover and the connection section respectively. A rotor core and a permanent magnet of the brushless motor are surrounded by the stator core. The stator core is fixedly installed on the inner wall of the first shell section, and the first shell section is a cylindrical shell. And the second shell section extends along the axial direction, has a non-circular cross section and is used as a connecting section of the integrated brushless motor. And a circuit board assembly of the brushless motor is at least partially accommodated in the second shell section. According to the invention, the stator of the motor is respectively connected and accommodated through the segmented motor shell, and the reduction gear box is integrated, so that the overall miniaturization of the brushless motor and the driving device can be maintained, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a drive device and a brushless motor. Background Technology

[0002] Traditional motor housings are cylindrical to make full use of their internal space, allowing for larger stator cores, larger stator windings, and / or larger rotor cores. However, this type of housing is prone to relative rotation when assembled with the gearbox, requiring additional fasteners to prevent this rotation and complicating the assembly process.

[0003] In one existing improvement, the motor housing has flat sections on both sides to prevent relative rotation during assembly of the motor and gearbox. However, this housing is formed by rolling metal sheets. A drawback of this approach is that dovetail grooves need to be punched into the edges before rolling the metal sheets to facilitate interlocking and welding after rolling. This makes the manufacturing process complex and costly. An optimized solution is urgently needed. Summary of the Invention

[0004] The purpose of this invention is to reduce the cost of motors and drive devices.

[0005] The first aspect of the present invention provides a brushless motor, including a stator and a rotor rotatably mounted to the stator; the stator includes a motor housing, a stator core fixedly mounted to the inner wall of the motor housing, and a winding wound to the stator core; the rotor includes a rotor core rotatably housed within the stator and a permanent magnet fixedly mounted to the rotor core; The motor housing includes a first end cap, a first housing segment, a connecting segment, and a second housing segment; the first housing segment is a cylindrical shell, and its two ends are respectively connected to the first end cap and the connecting segment; the second housing segment extends axially and has a non-circular cross-section, and the maximum outer diameter of the second housing segment is greater than the outer diameter of the first housing segment; the connecting segment extends radially outward from the end of the first housing segment and in a direction close to the second housing segment, and connects to the second housing segment; the first end cap, the first housing segment, the connecting segment, and the second housing segment are a one-piece integral piece made of metal. The stator core is fixedly mounted to the inner wall of the first housing section, and the rotor core and permanent magnet are surrounded by the stator core; the circuit board assembly of the brushless motor is at least partially housed in the second housing section.

[0006] A second aspect of the present invention provides a drive device including a motor and a reduction gearbox connected to the motor, wherein the motor is a brushless motor as described in the first aspect of the present invention; the rotor further includes a rotor shaft rotatably connected to an input gear of the reduction gearbox; the reduction gearbox further includes a connector connected to the motor housing.

[0007] In a preferred embodiment, the connecting portion of the reduction gearbox is connected to and housed within the second housing section.

[0008] In a preferred embodiment, the connecting section serves as a first defining portion of the connector to define the depth of the axial connection of the connector.

[0009] In a preferred embodiment, the axial length of the connector is equal to the axial length of the second housing segment.

[0010] In a preferred embodiment, the second housing segment includes a riveting portion, a second limiting portion, and a tolerance notch; the riveting portion is riveted to the connector; the second limiting portion is a non-circular part of the second housing segment to limit the rotation of the second housing segment and the connector relative to each other; the tolerance notch is used to adjust the diameter of the second housing segment.

[0011] In a preferred embodiment, the tolerance notch serves as a third limiting portion of the connector, and the connector is provided with a plug-in portion adapted to the tolerance notch to limit the connection direction and connection depth between the connector and the second housing segment.

[0012] In a preferred embodiment, the connector has a through hole through which the rotor shaft passes; one end of the rotor shaft is rotatably connected to a first end cover via a first bearing; a second bearing is disposed in the through hole of the connector, and the other end of the rotor shaft is rotatably connected to the connector via the second bearing.

[0013] In a preferred embodiment, the connector is provided with a protrusion or a recess that is riveted to the riveting portion.

[0014] In a preferred embodiment, the shape and dimensions of the first housing segment are adapted to the shape and dimensions of the stator core; the shape and dimensions of the second housing segment are adapted to the shape and dimensions of the connector.

[0015] The motor housing structure of the present invention includes a first housing section, a connecting section, and a second housing section; the first housing section is cylindrical to make the most of the space inside to install the stator core; the second housing section is non-circular to avoid relative rotation during assembly with the gearbox, thereby reducing assembly costs; the motor housing as a whole is a one-piece integral piece stretched or stamped from a metal part, which reduces manufacturing costs. Attached Figure Description

[0016] Figure 1 This is a perspective view of a driving device provided in an embodiment of the present invention; Figure 2 yes Figure 1 An exploded view of the drive device shown. Figure 3 This is a three-dimensional schematic diagram of the brushless motor provided in an embodiment of the present invention; Figure 4 yes Figure 3 An exploded view of the brushless motor shown. Figure 5 This is a three-dimensional schematic diagram of the reduction gearbox provided in an embodiment of the present invention; Figure 6 yes Figure 1 A longitudinal sectional view of the drive device shown; Figure 7 This is a three-dimensional schematic diagram of the motor housing of a brushless motor provided in another embodiment of the present invention; Figure 8 yes Figure 7 A three-dimensional schematic diagram of the motor casing from another perspective. Detailed Implementation

[0017] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0018] Please see Figure 1 and Figure 2 The present invention provides a drive device 200, including a motor and a reduction gearbox 50 connected to the motor.

[0019] This motor is a brushless motor 100. Please refer to [link / reference]. Figure 3 and Figure 4 The brushless motor 100 includes a stator 1, a rotor 2 rotatably mounted to the stator 1, and a circuit board assembly 3. The stator 1 is an outer stator, and the rotor 2 is an inner rotor.

[0020] Specifically, the stator 1 includes a motor housing 10, a stator core 11 fixedly mounted to the inner wall of the motor housing 10, and windings wound around the stator core 11. The rotor 2 includes a rotor core rotatably housed within the stator 1 and permanent magnets fixedly mounted to the rotor core. The rotor core and permanent magnets are surrounded by the stator core 11. Thus, the control module in the circuit board assembly 3 generates a rotating magnetic field by controlling the current direction of the windings, which drives the rotor 2 to rotate.

[0021] Please see Figure 2 , Figure 3 , Figure 4 and Figure 5In this embodiment, the reduction gearbox 50 has a connector 51 that connects to the motor housing 10. Specifically, the motor housing 10 includes a first end cover 12, a first housing section 13, a connecting section 14, and a second housing section 15. The first end cover 12 and the connecting section 14 are respectively connected to the two ends of the first housing section 13. The connecting section 14 extends radially outward from the end of the first housing section 13 and in a direction close to the second housing section 15, and connects to the second housing section 15.

[0022] In this embodiment, the first end cap 12, the first outer shell segment 13, the connecting segment 14, and the second outer shell segment 15 are one-piece integral parts made of metal. For example, by using a stretching or stamping one-piece forming process, the different shell segments of the motor housing 10 can be formed into different sizes and shapes, which can reduce manufacturing costs.

[0023] The stator core 11 is fixedly mounted to the inner wall of the first housing section 13. The connecting part 51 of the reduction gearbox 50 is connected to the second housing section 15. Preferably, the shape and dimensions of the first housing section 13 are adapted to the shape and dimensions of the stator core 11; the shape and dimensions of the second housing section 15 are adapted to the shape and dimensions of the connecting part 51. In this way, while maintaining product miniaturization, the assembly cost of the reduction gearbox 50 and the brushless motor 100 can also be reduced.

[0024] In this embodiment, the stator core 11 has a cylindrical outer wall; the first outer shell section 13 is a cylindrical shell. Preferably, the second outer shell section 15 extends axially and has a non-circular cross-section; the connector 51 is also non-cylindrical; to prevent the electric housing 10 and the connector 51 from rotating relative to each other, causing the connection to loosen or detach; thereby reducing the assembly cost of the reduction gearbox 50 and the brushless motor 100.

[0025] Preferably, the connection dimension of the connector 51 is substantially equal to the inner diameter of the second housing segment 15, and the connector 51 is received within the inner cavity of the second housing segment 15. In other embodiments, the second housing segment 15 may also be inserted into the groove of the connector 51 to achieve the connection between the two.

[0026] Understandably, the maximum outer diameter of the second housing segment 15, which has a non-circular cross-section, is larger than the outer diameter of the cylindrical first housing segment 13. The circuit board assembly 3 of the brushless motor is at least partially housed in the second housing segment 13. For example, the circuit board assembly 3 includes a control module and a Hall sensor. The housing of the circuit board assembly 3 in the second housing segment 13 facilitates the control connection between the brushless motor 100 and the reduction gearbox 50 at both ends of the second housing segment 15, and also allows the first end cover 12 and the first housing segment 13 to only cover the stator 1, thus maintaining the miniaturization of the brushless motor 100.

[0027] Preferably, the connecting section 14 has an outer diameter that gradually decreases in the direction from the second outer shell section 15 toward the first outer shell section 13. When the connecting portion 51 is connected to the second outer shell section 15, the connecting section 14 serves as a first limiting portion of the connector 51 to limit the depth of axial connection of the connector 51. When the connector 51 extends into the portion of the connecting section 14 with its decreasing outer diameter near the first outer shell section 13, the connector 51 is prevented from going any further and is limited to the current axial depth.

[0028] More preferably, the axial length of the connector 51 is equal to the axial length of the second housing segment 15, in order to limit and maintain the overall length of the drive unit 200.

[0029] Preferably, the second housing segment 15 includes a riveting portion 151, a second limiting portion 152, and a tolerance notch 153. The riveting portion 151 is used for riveting with the connector 51 to further reinforce the connection between the second housing segment 15 and the connector 51. Please refer to [link / reference]. Figure 3 and Figure 4 The connector 51 is provided with a recess 513 that is riveted to the riveting portion 151. In other embodiments, when the riveting portion 151 is concave, the connector 51 may be provided with a protrusion that is riveted to the riveting portion 151.

[0030] The second limiting portion 152 is a non-circular part of the second outer shell segment 15, which limits the rotation between the second outer shell segment 15 and the connecting member 51. It is understood that any motor housing 10 with a non-circular second outer shell segment 15 can achieve an anti-rotation effect. In this embodiment, the second outer shell segment 15 is a square. In other embodiments, the second outer shell segment 15 can be other shapes with non-circular portions. For example, please refer to... Figure 7 and Figure 8 The second outer shell segment 15 can be elliptical in shape with a flat portion.

[0031] Please see Figure 2 and Figure 3 The tolerance notch 153 is used to adjust the diameter of the second housing segment 15 to ensure that the connector 51 is accommodated in the inner cavity of the second housing segment 15, maintaining the overall miniaturized size of the drive device 200 and the stability of the connection. Understandably, the tolerance notch 153 also serves as a third limiting portion for the connector 51. The connector 51 is provided with a plug-in portion 511 adapted to the tolerance notch 153 to limit the connection direction and connection depth between the connector 51 and the second housing segment 15.

[0032] Please see Figure 3 , Figure 4 and Figure 6The rotor 2 also includes a rotor shaft 25, which is rotatably connected to the input gear of the reduction gearbox 50. A connecting member 51 has a through hole through which the rotor shaft 25 passes, extending into and connecting to the input gear of the reduction gearbox 50. One end of the rotor shaft 25 is rotatably connected to the first end cover 12 via a first bearing 6. A second bearing 8 is disposed within the through hole of the connecting member 51, and the other end of the rotor shaft 25 is rotatably connected to the connecting member 51 via the second bearing 8. This supports the rotor shaft 25 and provides smooth operating power to the reduction gearbox 50.

[0033] The above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, such as combining different features in various embodiments, and these all fall within the protection scope of the present invention.

Claims

1. A brushless motor, comprising a stator (1) and a rotor (2) rotatably mounted to the stator (1); the stator (1) comprising a motor housing (10), a stator core (11) fixedly mounted to the inner wall of the motor housing (10), and windings wound to the stator core (11); the rotor (2) comprising a rotor core rotatably housed within the stator (1) and a permanent magnet fixedly mounted to the rotor core; characterized in that: The motor housing (10) includes a first end cap (12), a first housing section (13), a connecting section (14), and a second housing section (15); the first housing section (13) is a cylindrical housing, and the two ends of the first housing section (13) are respectively connected to the first end cap (12) and the connecting section (14); the second housing section (15) extends axially and has a non-circular cross-section, and the maximum outer diameter of the second housing section (15) is greater than the outer diameter of the first housing section (13); the connecting section (14) extends radially outward from the end of the first housing section (13) in a direction close to the second housing section (15) and is connected to the second housing section (15); the first end cap (12), the first housing section (13), the connecting section (14), and the second housing section (15) are a one-piece integral piece drawn or stamped from metal parts; The stator core (11) is fixedly mounted to the inner wall of the first housing section (13), and the rotor core and permanent magnet are surrounded by the stator core (11); the circuit board assembly (3) of the brushless motor is at least partially housed in the second housing section (13).

2. The brushless motor according to claim 1, characterized in that, The connecting section (14) forms a first limiting part to limit the maximum depth to which the reduction gearbox housing is inserted into the second outer shell section (15); the non-circular portion of the second outer shell section (15) also forms a second limiting part (152) to prevent the second outer shell section (15) from rotating relative to the reduction gearbox housing inserted into the second outer shell section (15).

3. The brushless motor according to claim 1, characterized in that, The second housing segment (15) also has a tolerance notch (153) at its open end to accommodate tolerances; the opening of the tolerance notch (153) also has a riveting part (151) for being bent inward to be riveted to the reduction gearbox housing inserted into the second housing segment (15).

4. A drive device comprising a motor and a reduction gearbox (50) connected to the motor, the motor being a brushless motor (100) as claimed in claim 1; the rotor (2) further comprising a rotor shaft (25) rotatably connected to an input gear of the reduction gearbox (50); the reduction gearbox (50) further comprising a connector (51) connected to the motor housing (10); the connecting portion (51) of the reduction gearbox (50) being connected to and received into a second housing segment (15).

5. The driving device according to claim 4, characterized in that, The connecting section (14) serves as the first defining part of the connector (51) to define the depth of the axial connection of the connector (51); the axial length of the connector (51) is equal to the axial length of the second housing section (15).

6. The driving device according to claim 4, characterized in that, The second outer shell segment (15) includes a riveting part (151), a second limiting part (152), and a tolerance notch (153); the riveting part (151) is riveted to the connector (51); the second limiting part (152) is a non-circular part of the second outer shell segment (15) to limit the rotation of the second outer shell segment (15) and the connector (51) relative to each other; the tolerance notch (153) is used to adjust the diameter of the second outer shell segment (15).

7. The driving device according to claim 6, characterized in that, The tolerance notch (153) serves as the third limiting part of the connector (51). The connector (51) is provided with a plug-in part (511) adapted to the tolerance notch (153) to limit the connection direction and connection depth between the connector (51) and the second outer shell segment (15).

8. The driving device according to claim 4, characterized in that, The connector (51) has a through hole through which the rotor shaft (25) passes; one end of the rotor shaft (25) is rotatably connected to the first end cover (12) via the first bearing (6); a second bearing (8) is provided in the through hole of the connector (51), and the other end of the rotor shaft (25) is rotatably connected to the connector (51) via the second bearing (8).

9. The driving device according to claim 6, characterized in that, The connector (51) is provided with a protrusion or recess (513) that is riveted to the riveting part (151).

10. The driving device according to claim 4, characterized in that, The shape and size of the first outer shell segment (13) are adapted to the shape and size of the stator core (11); the shape and size of the second outer shell segment (15) are adapted to the shape and size of the connector (51).

Images