A motor braking device and an outer rotor motor

Abstract

The application discloses a motor braking device, which comprises a steel band, the steel band is wound into a spiral shape, one end of the steel band is fixed and the other end is movable, and the motor braking device further comprises a driving assembly, the driving assembly is matched with the movable end of the steel band and drives the movable end of the steel band to move, so that the radius of the spiral wound by the steel band is increased or decreased. The application further discloses an external rotor motor, which comprises a stator, a rotor and a motor shell, and further comprises the motor braking device, the motor braking device is arranged on the motor shell, the steel band is arranged around the rotor and the motor shell covers the steel band. The motor braking device is convenient to operate, can save energy, is beneficial to reducing the overall weight of the external rotor motor, and is convenient to flexibly adjust the fast braking or slow braking of the external rotor motor, so that the external rotor motor can meet the use requirements of specific working scenes.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a motor braking device and an external rotor motor having the motor braking device. Background Technology

[0002] Because the rotor of a running motor will continue to rotate for a period of time under the action of inertia after the power supply is stopped, some applications require the motor to stop quickly after the power supply is stopped, or the motor needs to stay in a certain position for a long time. Therefore, some existing motors are equipped with braking devices to brake the rotor.

[0003] Currently, the braking methods used in motors on the market include mechanical braking and electric braking. Mechanical braking commonly uses electromagnetic brakes and electromagnetic clutches. These mechanical braking devices require continuous power supply, resulting in high energy consumption, and some are also bulky, hindering the reduction of motor size. Electric braking devices also require continuous power supply during braking, and their braking torque is limited by the temperature rise of the motor windings, leading to high energy consumption and limited braking torque. Therefore, in applications requiring long range and lightweight design, a braking device with low energy consumption, light weight, and braking torque not limited by winding temperature rise is needed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a braking device with low energy consumption and light weight, and an external rotor motor having the braking device.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a motor braking device, including a steel belt, the steel belt is wound into a spiral shape, one end of the steel belt is fixed and the other end is movable, and a driving component is also included. The driving component cooperates with the movable end of the steel belt and drives the movable end of the steel belt to move, so that the radius of the spiral formed by the steel belt increases or decreases.

[0006] To solve the above-mentioned technical problems, the present invention also adopts the following technical solution: an external rotor motor, including a stator, a rotor and a motor housing, and also including the above-mentioned motor braking device, wherein the motor braking device is disposed on the motor housing, a steel belt is disposed around the rotor and the motor housing covers the steel belt.

[0007] The beneficial effects of this invention are as follows: The external rotor motor provided by this invention uses a motor braking device mounted on the motor housing to mechanically brake the rotor. The motor braking device includes a steel belt and a drive assembly. The steel belt is wound around the rotor in a spiral shape, with one end fixed and the other end movable. The drive assembly is used to drive the movable end of the steel belt to move, thereby increasing or decreasing the radius of the spiral formed by the steel belt. When braking the rotor is required, the drive assembly drives the radius of the spiral formed by the steel belt to decrease, so that the steel belt grips the rotor tightly. The friction between the steel belt and the rotor stops the rotor from rotating, thus achieving the purpose of braking. After the steel belt contacts the rotor, it tightens and wraps around the rotor as the rotor rotates, generating a sufficiently large frictional force. This system stops the rotor from rotating, effectively preventing brake failure and ensuring the rotor stops rotating within a short time. When restarting the external rotor motor, the drive assembly moves the movable end of the steel belt to increase the radius of the spiral formed by the steel belt. At this time, the steel belt separates from the rotor, allowing the rotor to rotate normally. The operation is convenient. During braking, the drive assembly only needs to generate a traction force to bring the steel belt close to and into contact with the rotor. This saves energy and allows for a more compact internal layout of the external rotor motor, reducing the overall weight of the external rotor motor. Furthermore, the braking effect can be adjusted by controlling the magnitude of the traction force generated by the drive assembly on the steel belt, facilitating flexible adjustment of the external rotor motor for fast or slow braking, enabling the external rotor motor to meet the usage requirements of specific working scenarios. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the external rotor motor according to Embodiment 1 of the present invention;

[0009] Figure 2 This is a cross-sectional view of the external rotor motor according to Embodiment 1 of the present invention;

[0010] Figure 3 This is a partial exploded view of the external rotor motor of Embodiment 1 of the present invention;

[0011] Figure 4 This is a partial structural schematic diagram of the external rotor motor according to Embodiment 1 of the present invention;

[0012] Figure 5 This is a partial structural schematic diagram of the external rotor motor according to Embodiment 1 of the present invention;

[0013] Figure 6 This is a schematic diagram of the motor braking device in the external rotor motor according to Embodiment 1 of the present invention;

[0014] Figure 7 This is an exploded view of the drive assembly in the external rotor motor according to Embodiment 1 of the present invention;

[0015] Figure 8 This is a schematic diagram of the steel belt structure in the external rotor motor of Embodiment 1 of the present invention.

[0016] Label Explanation:

[0017] 100. Stator; 200. Rotor; 300. Steel strip; 301. Fixed end; 302. Moving end; 400. Drive assembly; 401. Drive component; 402. Screw; 403. Moving block; 404. Traction component; 405. Limiting part; 406. Sleeve; 407. Connecting buckle; 408. Elastic component; 410. Mounting base; 411. Guide rod; 500. Motor housing; 501. Mounting groove; 502. Receiving groove; 503. Cover plate; 600. Driver; 700. Dust cover. Detailed Implementation

[0018] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0019] Please refer to Figures 1 to 8 An electric motor braking device includes a steel belt 300 wound into a spiral shape, with one end of the steel belt 300 fixed and the other end movable. It also includes a drive assembly 400, which cooperates with the movable end of the steel belt 300 and drives the movable end of the steel belt 300 to move, thereby increasing or decreasing the radius of the spiral formed by the steel belt 300.

[0020] As can be seen from the above description, the beneficial effects of the present invention are as follows: the motor braking device provided by the present invention is easy to operate, can effectively avoid braking failure and ensure that the rotor 200 stops rotating in a short time, saves energy, and makes the internal layout of the external rotor motor more compact, which helps to reduce the overall weight of the external rotor motor, and facilitates flexible adjustment of the external rotor motor for fast or slow braking, so that the external rotor motor can meet the usage requirements of specific working scenarios.

[0021] Furthermore, the number of steel strips 300 can be designed to be two according to different application scenarios. The central axis of the spiral formed by the two steel strips 300 is the same straight line, and the drive component 400 is respectively engaged with the movable end of the two steel strips 300.

[0022] As described above, the number of steel belts 300 is set to two, and the movable ends 302 of the two steel belts 300 move synchronously under the drive of the drive assembly 400. During braking, the two steel belts 300 simultaneously contact the rotor 200 and wrap around the rotor 200 to ensure that a sufficiently large frictional force is generated to stop the rotor 200 quickly.

[0023] Furthermore, the movable end of one of the steel strips 300 moves clockwise relative to the fixed end of the steel strip 300, and the movable end of the other steel strip 300 moves counterclockwise relative to the fixed end of the steel strip 300, and the radius of the spiral formed by the two steel strips 300 increases or decreases synchronously.

[0024] As described above, the movable ends of the two steel strips 300 move in opposite directions relative to the fixed ends under the drive of the drive assembly 400. Furthermore, the two steel strips 300 simultaneously contract and wrap around the rotor 200 under the drive of the drive assembly 400, or simultaneously open and move away from the rotor 200 under the drive of the drive assembly 400. That is, after the two steel strips 300 are installed on the external rotor motor, the spiral shape formed by the two steel strips 300 has opposite rotation directions from the fixed end to the movable end. When the rotor 200 of the external rotor motor rotates clockwise or counterclockwise... During rotation, the steel belt 300 with the same rotation direction as the rotor 200 tightens and wraps around the rotor 200 as the rotor 200 rotates to generate the main braking torque. The steel belt 300 with the opposite rotation direction to the rotor 200 is driven by the drive assembly 400 to wrap around the rotor 200 to generate the secondary braking torque. This ensures that the motor braking device can generate sufficient friction to stop the rotor 200 quickly when the external rotor motor rotates forward and in reverse. This allows the motor braking device to be applicable to both forward and reverse rotation of the rotor 200.

[0025] Furthermore, the drive assembly 400 includes a drive member 401, a screw 402 that cooperates with the drive member 401, and a moving block 403 sleeved on the screw 402. The moving block 403 can move along the axial direction of the screw 402 on the screw 402. The moving block 403 is provided with a traction member 404, and the traction member 404 is fixedly connected to one movable end of the steel belt 300.

[0026] As described above, the drive assembly 400 uses a drive member 401 to drive the screw 402 to rotate, causing the moving block 403 to move along the axial direction of the screw 402. When the moving block 403 moves, it pulls the traction member 404, which is fixedly connected to the movable end of the steel belt 300, thereby driving the movable end of the steel belt 300 to move, so that the steel belt 300 clamps the rotor 200 to achieve braking.

[0027] Furthermore, the moving block 403 is provided with a protruding limiting part 405, and the traction member 404 is fitted with a sleeve 406 and the sleeve 406 abuts against the limiting part 405.

[0028] As described above, the sleeve 406 is fitted onto the traction member 404 to reduce friction between the traction member 404 and other components of the external rotor motor. This can prevent wear on the components of the external rotor motor or the traction member 404, thus extending the service life of the motor braking device. It can also prevent the traction member 404 from moving slowly due to friction, thus affecting the movement of the steel belt 300 and ensuring that the motor braking device can respond quickly to control commands.

[0029] Furthermore, the traction member 404 has a connecting buckle 407 at one end near the steel belt 300, and the connecting buckle 407 is fixedly connected to the movable end of the steel belt 300.

[0030] As described above, the traction component 404 and the steel belt 300 are fixedly connected by a connecting buckle 407 at the end of the traction component 404 to improve the stability of the connection between the traction component 404 and the steel belt 300, and to prevent the connection between the two from breaking when the traction component 404 pulls the steel belt 300 to move, which would cause the motor braking device to fail.

[0031] Furthermore, an elastic element 408 is also sleeved on the traction member 404, and one end of the elastic element 408 in the telescopic direction abuts against the connecting buckle 407.

[0032] As described above, an elastic element 408 is fitted onto the traction member 404. When the traction member 404 pulls the steel belt 300, reducing the radius of the spiral formed by the steel belt 300, the elastic element 408 is compressed. When the steel belt 300 moves away from the rotor 200 and releases the rotor 200, the steel belt 300 not only resets under its own elasticity but also experiences the elastic force generated by the elastic element 408 during the process of restoring its original length. This ensures that the steel belt 300 is completely reset and separated from the rotor 200, preventing the steel belt 300 from affecting the normal rotation of the rotor 200. At the same time, the elastic element 408 can provide a certain supporting force to prevent the steel belt 300 from locking up instantly upon contact with the rotor 200, thus achieving the function of slow braking.

[0033] Furthermore, the drive assembly 400 also includes a mounting base 410 and the drive member 401 is disposed on the mounting base 410. The mounting base 410 is also provided with a guide rod 411, the guide rod 411 is parallel to the screw 402, and the moving block 403 is provided with a through hole that cooperates with the guide rod 411.

[0034] As described above, the guide rod 411 on the mounting base 410 guides the moving block 403 to move in a preset direction, preventing unexpected offset when the moving block 403 moves, which could cause a gap between the steel belt 300 and the rotor 200 and affect the braking effect of the motor braking device.

[0035] An external rotor motor includes a stator 100, a rotor 200, and a motor housing 500. It also includes the aforementioned motor braking device, which is disposed on the motor housing 500. A steel belt 300 is arranged around the rotor 200 and the motor housing 500 covers the steel belt 300.

[0036] Furthermore, the motor housing 500 is provided with a mounting groove 501 for accommodating the drive assembly 400, and the inner peripheral wall of the motor housing 500 is provided with a receiving groove 502 for accommodating the steel strip 300, and the mounting groove 501 is connected to the receiving groove 502.

[0037] As described above, the motor housing 500 is provided with a mounting groove 501 for mounting the drive assembly 400 and a receiving groove 502 for accommodating the steel strip 300, so that the position of the motor braking device on the external rotor motor is kept stable, and the steel strip 300 is contained in the receiving groove 502 to prevent dust, debris and other foreign objects from the external environment from falling into the motor braking device, thus protecting the motor braking device and enabling the motor braking device to operate stably.

[0038] Example 1

[0039] Please refer to Figures 1 to 8 Embodiment 1 of the present invention is as follows: Figure 1 and Figure 2 As shown, an external rotor motor includes a stator 100, a rotor 200, and a motor housing 500. The stator 100 is fixed to the motor housing 500 by screws or other connecting parts. The motor housing 500 is provided with a motor braking device. The motor braking device is used to brake the rotor 200 when the external rotor motor needs to brake, so as to reduce the speed of the rotor 200 or to stop the rotor 200 from rotating quickly, and to lock the rotor 200 when the external rotor motor needs to stop at a certain position.

[0040] like Figure 3 As shown, the motor braking device includes a steel belt 300 and a drive assembly 400. The steel belt 300 is wound into a spiral shape and surrounds the rotor 200. The two opposite ends of the steel belt 300 are a fixed end 301 and a movable end 302, respectively. The fixed end 301 is fixed to the stator 100, and the movable end 302 can move circumferentially along the rotor 200. The drive assembly 400 cooperates with the movable end 302 of the steel belt 300, and the movable end 302 of the steel belt 300 can move under the drive of the drive assembly 400 to increase or decrease the radius of the spiral formed by the steel belt 300.

[0041] Specifically, when the external rotor motor is in normal operation, there is a gap between the steel belt 300 and the rotor 200, allowing the rotor 200 to rotate normally. When the external rotor motor needs to be braked, the drive assembly 400 drives the movable end 302 of the steel belt 300 to move circumferentially along the rotor 200, reducing the radius of the spiral formed by the steel belt 300, causing the steel belt 300 to contact the rotor 200 and clamp it tightly. At this time, the friction between the steel belt 300 and the rotor 200 forces the rotor to brake. When the rotor 200 stops rotating, and the steel belt 300 comes into contact with the rotor 200, the steel belt 300 will tighten as the rotor 200 rotates to generate a sufficiently large frictional force, thereby achieving the purpose of braking; when the external rotor motor needs to resume normal operation, the drive assembly 400 drives the movable end 302 of the steel belt 300 to move along the circumference of the rotor 200 to increase the radius of the spiral formed by the steel belt 300, so that the steel belt 300 resets and separates from the rotor 200, and then the rotor 200 can rotate normally.

[0042] Please combine Figure 3 , Figure 4 and Figure 5 The motor housing 500 covers the steel strip 300 and the rotor 200. The inner peripheral wall of the motor housing 500 is provided with a receiving groove 502 for accommodating the steel strip 300. When the steel strip 300 is in a state of being spaced apart from the rotor 200, the steel strip 300 is contained in the receiving groove 502. The motor housing 500 is also provided with a mounting groove 501 for mounting the drive assembly 400 and a cover plate 503 covering the opening of the mounting groove 501. The cover plate 503 is snapped into the motor housing 500. The motor housing 500 is used to prevent dust, debris and other foreign objects from the external environment from falling into the motor braking device to protect the motor braking device. After the cover plate 503 is removed from the motor housing 500, part of the motor braking device can be exposed to facilitate the later maintenance of the external rotor motor.

[0043] like Figure 3 and Figure 6 As shown, in this embodiment, there are two steel belts 300, and the central axes of the spirals formed by the two steel belts 300 are the same straight line. The drive assembly 400 cooperates with the movable ends 302 of the two steel belts 300 respectively, so that the movable ends 302 of the two steel belts 300 can move synchronously under the drive of the drive assembly 400. When braking, the two steel belts 300 simultaneously contact the rotor 200 and hold the rotor 200 tightly, so that a sufficiently large frictional force is generated between the steel belts 300 and the rotor 200 to make the rotor 200 stop quickly.

[0044] In detail, the movable end of one of the steel strips 300 moves clockwise relative to the fixed end, and the movable end of the other steel strip 300 moves counterclockwise relative to the fixed end. The radii of the spirals formed by the two steel strips 300 increase or decrease synchronously under the drive of the drive assembly 400. That is, the two steel strips 300 simultaneously contract and wrap around the rotor 200, or simultaneously open and move away from the rotor 200. In other words, after the two steel strips 300 are installed on the external rotor motor, one steel strip 300 forms a clockwise spiral from the fixed end 301 to the movable end 302, and the other steel strip 300 forms a counterclockwise spiral from the fixed end 301 to the movable end 302. The spiral directions of the two steel strips 300 are respectively suitable for... The description covers two operating modes: forward rotation and reverse rotation of the rotor 200. When the rotor 200 of the external rotor motor rotates clockwise or counterclockwise, the steel belt 300 with the same rotation direction as the rotor 200 contacts the rotor 200 under the drive of the drive assembly 400. It then tightens and wraps around the rotor 200 as the rotor 200 rotates to generate the main braking torque. The steel belt 300 with the opposite rotation direction to the rotor 200 wraps around the rotor 200 under the drive of the drive assembly 400 to generate a secondary braking torque. That is, the two steel belts 300 will tighten synchronously and contact the rotor 200, ensuring that the motor braking device can generate sufficient friction to stop the rotor 200 quickly when the external rotor motor rotates forward and reverse, thus ensuring that the motor braking device has a good braking effect on the rotor 200 in both forward and reverse rotation.

[0045] Optionally, when the rotation direction of the rotor 200 in the external rotor motor is fixed, the motor braking device only needs to be equipped with a steel belt 300 whose rotation direction is consistent with the rotation direction of the rotor 200.

[0046] Please refer to Figure 6 and Figure 7The drive assembly 400 includes a mounting base 410 fixedly connected to the motor housing 500. The mounting base 410 is provided with a drive member 401 and a screw 402 cooperating with the drive member 401. A movable block 403 is sleeved on the screw 402, and the movable block 403 has a threaded hole cooperating with the screw 402. The drive member 401 drives the screw 402 to rotate, causing the movable block 403 to move along the axial direction of the screw 402. A traction member 404 is provided on the movable block 403, and the traction member 404 is fixedly connected to the movable end 302 of the steel belt 300. As the movable block 403 moves, the traction member 404 moves synchronously with the movable block 403 and pulls the steel belt 300, causing the steel belt 300 to move. The movable end 302 of the rotor 200 moves, and when the movable block 403 moves towards the axis of the rotor 200, the steel belt 300 tightens under the pull of the traction member 404. When the movable block 403 moves away from the axis of the rotor 200, the traction member 404 and the steel belt 300 reset. That is, during braking, the drive assembly 400 only needs to generate a traction force to bring the steel belt 300 close to and into contact with the rotor 200, saving energy. After the motor braking device brakes, the movable block 403 remains in the position where the steel belt 300 hugs the rotor 200, ensuring that the rotor 200 can still maintain braking torque after the motor braking device is de-energized, without needing to continuously supply power to the motor braking device, thus reducing energy consumption. In this embodiment, the traction member 404 is a steel wire, but the traction member 404 can also be made of other flexible non-metallic materials, such as nylon.

[0047] In detail, to ensure that the moving block 403 moves in a preset direction, the mounting base 410 is also provided with a guide rod 411, which is arranged parallel to the screw 402. The moving block 403 is provided with a through hole that cooperates with the guide rod 411, allowing the guide rod 411 to pass through the moving block 403. The guide rod 411 is used to guide the moving block 403 to move and prevent unexpected deviations from occurring during the movement of the moving block 403. This ensures that the steel belt 300 produces the expected action under the pull of the traction member 404, and prevents gaps between the steel belt 300 and the rotor 200 from affecting the braking effect of the motor braking device.

[0048] like Figure 2 and Figure 6As shown, the external rotor motor also includes a driver 600 and a dust cover 700. The dust cover 700 and the motor housing 500 form a cavity that accommodates the stator 100, the rotor 200 and the driver 600. The driver 600 is used to drive the external rotor motor to run and the driver 600 also controls the operation of the drive component 401, thereby controlling the operation of the motor braking device through the driver 600.

[0049] In detail, the travel of the moving block 403 can be adjusted by the driver 600 to adjust the displacement of the movable end 302 of the steel belt 300. After the steel belt 300 contacts or is wrapped around the rotor 200, the braking torque generated by the steel belt 300 on the rotor 200 increases with the increase of the displacement of the movable end 302. This allows for precise control of the braking torque generated by the steel belt 300 on the rotor 200 to adjust the braking effect of the motor braking device. This facilitates flexible adjustment of the external rotor motor for fast or slow braking, enabling the external rotor motor to meet the usage requirements of specific working scenarios.

[0050] Please combine Figure 4 and Figure 7 The moving block 403 is provided with a protruding limiting part 405. The traction member 404 is bent into a Z-shape. The traction member 404 is hung on the limiting part 405, and the opposite ends of the traction member 404 are respectively fixedly connected to the movable ends 302 of the two steel belts 300. A sleeve 406 is sleeved on the traction member 404. The sleeve 406 abuts against the limiting part 405 and covers the position where the traction member 404 contacts other components inside the external rotor motor. This reduces the friction between the traction member 404 and other components inside the external rotor motor, avoids wear on the traction member 404, and extends the service life of the motor braking device. It also prevents the slow movement of the traction member 404 caused by friction from affecting the movement of the steel belt 300, ensuring that the motor braking device can respond quickly to control commands.

[0051] like Figure 4 , Figure 7 and Figure 8As shown, a connecting buckle 407 is fixedly connected to one end of the traction member 404 near the steel belt 300. The connecting buckle 407 is fixed to the movable end 302 of the steel belt 300, so that the movable end 302 of the steel belt 300 is stably connected to the traction member 404, and the fixed end 301 of the steel belt 300 is fixed to the motor housing 500, ensuring that the connection between the fixed end 301 of the steel belt 300 and the motor housing 500 is reliable. When the steel belt 300 is pulled by the traction member 404, the position of its fixed end 301 remains stable, and the movable end 302 moves synchronously with the traction member 404. This causes the steel belt 300 to produce the expected action and hug and wrap the rotor 200 tightly, preventing the motor braking device from failing due to the steel belt 300 detaching from the traction member 404 or the motor housing 500. At the same time, it facilitates the assembly of the steel belt 300 with the traction member 404 and the motor housing 500.

[0052] Please refer to Figures 5 to 7 To ensure the steel belt 300 can smoothly return to its original position after moving away from the rotor 200, an elastic element 408 is also sleeved on the traction member 404. One end of the elastic element 408 abuts against the connecting buckle 407 in the extension and retraction direction, and the other end abuts against the motor housing 500. When the traction member 404 pulls the steel belt 300 to reduce the radius of the spiral formed by the steel belt 300, the elastic element 408 is compressed. When the steel belt 300 moves away from the rotor 200 and releases the rotor 200, the steel belt 300 returns to its original position under its own elasticity and is also subjected to the elastic force generated by the elastic element 408 during the process of returning to its original length. This ensures that the steel belt 300 is completely returned to its original position and separated from the rotor 200, preventing the steel belt 300 from affecting the normal rotation of the rotor 200. At the same time, the elastic element 408 can provide a certain support force to prevent the steel belt 300 from locking up at the moment of contact with the rotor 200, thus achieving the function of slow braking.

[0053] like Figure 1 and Figure 2As shown, the working process of the motor braking device in the external rotor motor provided in this embodiment is as follows: When the external rotor motor needs to brake, the driving member 401 drives the screw 402 to rotate, causing the moving block 403 to move towards the axis of the rotor 200. As the moving block 403 moves, the traction member 404 pulls the movable end 302 of the steel belt 300 and drives the steel belt 300 to move. At this time, the radius of the spiral formed by the steel belt 300 decreases, causing the steel belt 300 to hug the rotor 200 tightly. Through the steel belt 300 and the rotor 200... The friction between the rotors 200 and 00 causes the rotor speed to decrease rapidly and stop rotating, thus achieving braking. When the external rotor motor needs to return to normal operation, the drive member 401 drives the screw 402 to rotate, causing the moving block 403 to move away from the axis of the rotor 200. As the moving block 403 moves, the traction member 404 resets. At the same time, the steel belt 300 resets under the action of its own elasticity and the action of the elastic member 408. At this time, the steel belt 300 separates from the rotor 200, allowing the rotor 200 to rotate normally.

[0054] In summary, the motor braking device used in the external rotor motor provided by this invention includes a steel belt and a drive assembly. The drive assembly drives the steel belt to grip the rotor, and the friction between the steel belt and the rotor stops the rotor's rotation, thus achieving the purpose of braking. After the steel belt contacts the rotor, it tightens as the rotor rotates to generate sufficient friction to stop the rotor's rotation, effectively avoiding braking failure and ensuring that the rotor stops rotating in a short time. When restarting the external rotor motor, the drive assembly can be used to drive the steel belt away from the rotor to allow the rotor to rotate normally, making operation convenient. When braking, the drive assembly only needs to generate a traction force to bring the steel belt close to and into contact with the rotor. After braking, it does not need to continuously supply power to the drive assembly and the external rotor motor, which can effectively save energy. Furthermore, the motor braking device is lightweight, which helps to reduce the overall weight of the external rotor motor. The driving assembly can also control the displacement of the moving end of the steel belt to adjust the braking effect of the motor braking device, which facilitates flexible adjustment of the external rotor motor for fast or slow braking, enabling the external rotor motor to meet the usage requirements of specific working scenarios.

[0055] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An electric machine braking device, characterized by: The application relates to a motor brake device, which comprises a steel belt wound into a spiral, one end of the steel belt being fixed and the other end being movable, and a driving assembly matched with the movable end of the steel belt and used for driving the movable end of the steel belt to move, so that the radius of the spiral wound by the steel belt is increased or decreased. The driving assembly comprises a driving piece, a screw matched with the driving piece and a moving block sleeved on the screw, the moving block can move on the screw in the axial direction of the screw, a traction piece is arranged on the moving block and fixedly connected with the movable end of the steel belt, a protruding limiting part is arranged on the moving block, a sleeve is sleeved on the traction piece and abuts against the limiting part, one end of the traction piece close to the steel belt is provided with a connecting buckle fixedly connected with the movable end of the steel belt, an elastic piece is also sleeved on the traction piece, one end of the elastic piece in the stretching direction abuts against the connecting buckle, the driving assembly further comprises a mounting seat, the driving piece is arranged on the mounting seat, a guide rod is arranged on the mounting seat and parallel to the screw, and a through hole matched with the guide rod is arranged on the moving block.

2. An electric machine braking device according to claim 1, characterised in that: The number of the steel belts is two, the central axes of the spirals wound by the two steel belts are the same, and the driving assembly is matched with the movable ends of the two steel belts respectively.

3. An electric machine braking device according to claim 2, characterised in that: The movable end of one of the steel belts moves in the clockwise direction relative to the fixed end of the steel belt, the movable end of the other steel belt moves in the counterclockwise direction relative to the fixed end of the steel belt, and the radii of the spirals wound by the two steel belts are synchronously increased or decreased.

4. An external rotor motor comprising a stator, a rotor and a motor housing, characterized by: The motor brake device is arranged on the motor shell, the steel belt surrounds the rotor, and the motor shell covers the steel belt.

5. An external rotor electric machine according to claim 4, characterized in that: The motor shell is provided with a mounting groove accommodating the driving assembly, and the inner circumferential wall of the motor shell is provided with a containing groove accommodating the steel belt, and the mounting groove and the containing groove are communicated.

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