Outer rotor permanent magnet variable frequency motor for negative pressure fan

Abstract

The utility model discloses an outer rotor permanent magnet variable frequency motor for a negative pressure fan, which effectively facilitates the disassembly and maintenance of the motor, and comprises an outer rotor permanent magnet motor and a frequency converter positioned at the rear part of the outer rotor permanent magnet motor, the frequency converter comprises a first shell, a second shell and a frequency conversion assembly, the second shell is detachably connected to the rear side of the first shell through bolts, a connecting groove is formed in the outer side of the first shell, a positioning groove used for positioning the first shell is formed in the front side of the first shell, and the frequency conversion assembly is installed in the second shell. The device is simple and convenient to operate, effectively facilitates the connection between the outer rotor permanent magnet motor and the fan rack, prolongs the service life of the frequency converter, facilitates the maintenance of the outer rotor permanent magnet motor, improves the connection stability of the device and the rack, and improves the quality of the device.

Description

Technical Field

[0001] This utility model belongs to the field of external rotor motor technology, and relates to an external rotor permanent magnet variable frequency motor for negative pressure fans. Background Technology

[0002] In the industrial sector, negative pressure fans are widely used for ventilation, exhaust, and gas transport. Traditional negative pressure fans typically use AC motors as their drive units. However, due to their inherent structure and operating principle, traditional AC motors used in negative pressure fans suffer from high energy consumption and low efficiency, especially under partial or low load conditions, where the motor's efficiency further decreases, resulting in energy loss. Furthermore, the operation of the motor generates significant noise and vibration, causing inconvenience and discomfort to the working environment and personnel.

[0003] Furthermore, during the use of negative pressure fans, frequency converters are required for frequency adjustment. Typically, the frequency converter is externally connected to the negative pressure fan, resulting in a large overall size of the fan, making it difficult to adjust its position and move, thus affecting its portability. For example, Chinese patent CN219124087U discloses a dedicated frequency converter for negative pressure fans, including a frequency converter housing. A display is located at the front of the housing, and a frequency adjustment button is located below the display on the housing. Positioning and adjustment components are located on the bottom two sides of the housing. Although the structure of the frequency converter has been improved, increasing the overall flexibility of the negative pressure fan, the fact that the frequency converter is still externally connected to the fan means that motor maintenance remains inconvenient.

[0004] Another Chinese patent, CN220173060U, discloses an external rotor permanent magnet variable frequency motor for negative pressure fans, including an external rotor permanent magnet motor and a frequency converter installed at the rear end of the main shaft of the external rotor permanent magnet motor for controlling the speed and output power of the external rotor permanent magnet motor. The external rotor permanent magnet variable frequency motor for negative pressure fans provided in this application can operate efficiently and adjustablely, providing the required output power and speed. Meanwhile, the integrated frequency converter design simplifies the system structure and provides more convenient and precise speed control. However, in actual use, its structure of installing the device through a mounting slot has shortcomings. When maintenance of the motor and frequency converter is required, the entire frequency converter must be disassembled to remove the device, which is very inconvenient. Therefore, a more convenient maintenance-friendly external rotor permanent magnet variable frequency motor for negative pressure fans is needed to solve the above problems. Utility Model Content

[0005] To address the aforementioned problems, this invention proposes an external rotor permanent magnet variable frequency motor for negative pressure fans, which effectively solves the problems in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] An external rotor permanent magnet variable frequency motor for a negative pressure fan includes an external rotor permanent magnet motor and a frequency converter located at the rear of the external rotor permanent magnet motor. The frequency converter includes a first housing, a second housing, and a frequency conversion assembly. The second housing is detachably connected to the rear side of the first housing. The outer side of the first housing is provided with a connecting groove for fixing the first housing. The front side of the first housing is provided with a positioning groove for positioning the first housing. The frequency conversion assembly is installed inside the second housing.

[0008] Preferably, a first fixing ring is fixedly connected to the rear side of the first housing, and a second fixing ring is fixedly connected to the front side of the second housing. A bolt is threaded into the first fixing hole so that the first fixing ring and the second fixing ring are fixedly connected.

[0009] Preferably, a plurality of heat dissipation strips are fixedly connected to the rear side of the second housing.

[0010] Preferably, the external rotor permanent magnet motor includes a first end cover, a housing, and a second end cover. The outer sides of the first end cover, the housing, and the second end cover are provided with a plurality of second fixing holes. The first end cover and the second end cover are detachably connected to the front and rear sides of the housing through the corresponding second fixing holes.

[0011] Preferably, a connecting block is fixedly connected inside the positioning groove, and a weight-reducing groove is formed in the middle of the connecting block.

[0012] Preferably, the interior of the first housing is provided with a plurality of first reinforcing ribs arranged in a circular pattern.

[0013] Preferably, both the first end cap and the second end cap are provided with a plurality of second reinforcing ribs arranged in a circular pattern on the side near the housing.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. This utility model has multiple connecting slots, which can be detachably connected to the fan frame using bolts, thereby making it easy for workers to disassemble and install the device from the fan frame and to carry out maintenance.

[0016] 2. This utility model has a first reinforcing rib and a second reinforcing rib. By setting the first reinforcing rib and the second reinforcing rib, the bending strength of the front side of the first shell and the first end cover and the second end cover can be increased, thereby making the device more robust in use. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the overall structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the usage state of this utility model.

[0019] Figure 3 This is a schematic diagram of the exploded structure from the front view of this utility model.

[0020] Figure 4 This is an exploded structural diagram of the present invention from a rear view.

[0021] Figure 5 This is a schematic diagram showing the position of the connecting block in this utility model.

[0022] In the figure: 1. First housing; 2. Second housing; 3. Frequency converter assembly; 4. Connecting groove; 5. Positioning groove; 6. First fixing ring; 7. Second fixing ring; 8. First fixing hole; 9. Heat sink; 10. First end cover; 11. Housing; 12. Second end cover; 13. Second fixing hole; 14. Connecting block; 15. Weight reduction groove; 16. First reinforcing rib; 17. Second reinforcing rib. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] The following is in conjunction with the appendix Figures 1 to 5 The specific embodiments of this utility model will be described in further detail.

[0025] Depend on Figures 1 to 5 As shown, this utility model includes an external rotor permanent magnet motor and a frequency converter located at the rear of the external rotor permanent magnet motor. In order to facilitate the connection between the external rotor permanent magnet motor and the fan frame and to facilitate the disassembly and maintenance of the motor, the frequency converter includes a first housing 1, a second housing 2 and a frequency converter assembly 3. The second housing 2 is detachably connected to the rear side of the first housing 1 by bolts. The outer side of the first housing 1 is provided with a connecting groove 4 for fixing the first housing 1. The front side of the first housing 1 is provided with a positioning groove 5 for positioning the first housing 1. The frequency converter assembly 3 is installed inside the second housing 2.

[0026] Furthermore, such as Figure 2As shown, the outer side of the first housing 1 is provided with a connecting assembly that can be detachably connected to the connecting groove 4. The connecting assembly includes a connecting plate and a connecting sleeve. The connecting sleeve is fixedly connected to the side of the connecting plate away from the first housing 1. The connecting plate has a connecting hole that can be detachably connected to the connecting groove 4 by bolts. The connecting sleeve can be fitted or welded to a specific position in the middle of the frame.

[0027] In use, the first housing 1 can be connected to the fan frame. When connection is required, the position of the first housing 1 relative to the frame can be positioned first through the positioning groove 5. Then, it can be detachably connected to the frame through the connecting groove 4. After the installation between the first housing 1 and the frame is completed, the fan blades are installed at the output end of the external rotor permanent magnet motor to complete the assembly of the negative pressure fan.

[0028] Furthermore, by Figures 1 to 5 As shown, in order to facilitate the maintenance of the frequency converter, a first fixing ring 6 is fixedly connected to the rear side of the first housing 1, and a second fixing ring 7 is fixedly connected to the front side of the second housing 2. Both the first fixing ring 6 and the second fixing ring 7 are provided with multiple first fixing holes 8. The first fixing ring 6 and the second fixing ring 7 are detachably connected by bolts through the first fixing holes 8.

[0029] When the inverter needs to be repaired, the second fixing ring 7 can be removed from the back of the first fixing ring 6. At this time, the inverter component 3 inside the second fixing housing can be repaired without completely disassembling the inverter, which is convenient for staff to use.

[0030] Furthermore, by Figures 1 to 5 As shown, in order to increase the service life of the frequency converter, multiple heat dissipation strips 9 are fixedly connected to the rear side of the second housing 2;

[0031] In use, by setting the heat dissipation strip 9, the second housing 2 can be cooled by physical heat dissipation, which in turn can cool the frequency converter 3 fixedly connected inside the second housing 2.

[0032] Furthermore, by Figures 1 to 5 As shown, in order to facilitate the maintenance of the external rotor permanent magnet motor, the external rotor permanent magnet motor includes a first end cover 10, a housing 11 and a second end cover 12. The outer sides of the first end cover 10, the housing 11 and the second end cover 12 are provided with a plurality of second fixing holes 13. The first end cover 10 and the second end cover 12 are detachably connected to the front and rear sides of the housing 11 through the corresponding second fixing holes 13.

[0033] When in use, if it is necessary to inspect the external rotor permanent magnet motor, the first end cover 10 and the housing 11 can be removed in sequence as needed to facilitate the inspection of the internal structure of the housing 11.

[0034] Furthermore, by Figures 1 to 5 As shown, in order to increase the stability of the connection between the device and the frame, a connecting block 14 is fixedly connected inside the positioning groove 5. Each connecting groove 4 corresponds to the position of the connecting block 14. A weight reduction groove 15 is opened in the middle of the connecting block 14.

[0035] In use, by setting the connecting block 14, the position of the connecting groove 4 corresponds to the connecting block 14, that is, the depth of the connecting groove 4 can be increased without changing the side wall thickness of the first housing 1. Thus, when the connecting groove 4 is fixed to the fan frame, a longer bolt can be used, increasing the stability of the fixation between the two.

[0036] Furthermore, by Figures 1 to 5 As shown, in order to increase the mass of the device, the interior of the first housing 1 is provided with a plurality of first reinforcing ribs 16 arranged in a circle; the first end cover 10 and the second end cover 12 are each provided with a plurality of second reinforcing ribs 17 arranged in a circle on the side near the housing 11.

[0037] In use, by setting the first reinforcing rib 16 and the second reinforcing rib 17, the bending strength of the front side of the first housing 1 and the first end cover 10 and the second end cover 12 can be increased, thereby making the device more robust in use.

[0038] It should be further explained that, in this embodiment, the frequency converter is installed at the rear of the external rotor permanent magnet motor, and the speed and output power of the external rotor permanent magnet motor are controlled by the frequency converter; the external rotor permanent magnet motor also includes a main shaft, a cylindrical stator and a disc-shaped external rotor, the main shaft passes through the first end cover 10 and the second end cover 12, and the part of the main shaft extending out of the first end cover 10 has a threaded structure for installing fan blades, the fan blades are fixed on the mounting plate (not shown in the figure), and then installed on the main shaft through the mounting plate;

[0039] The stator consists of a stator core and stator windings. The stator core has a ring-shaped structure, and the stator windings are insulated and fixed to generate a magnetic field. The outer rotor consists of an outer rotor core and permanent magnets. The outer rotor core is fitted around the stator core, and the permanent magnets are fixedly mounted on the outer rotor core to generate a magnetic field. The outer rotor core is fixed to the main shaft, and the main shaft is connected to the first housing 1.

[0040] The rear end of the main shaft extends out of the rear side of the second end cover 12, and a shaft hole is opened on the first housing 1. The first housing 1 is installed on the main shaft through the shaft hole, so that the frequency converter is located on the outside of the main shaft.

[0041] The second housing 2 is connected to the rear end face of the first housing 1 to form a receiving cavity, and the frequency converter 3 is installed in the receiving cavity; preferably, the frequency converter 3 can be fixedly installed inside the second housing 2 by injection molding. The frequency converter 3 includes a circuit board, a power module and a control chip. The circuit board is installed inside the second housing 2, and the power module and control chip are installed on the circuit board to control the speed and output power of the motor, such as a frequency converter with model number AMK5000-4T0075G, which will not be described in detail here;

[0042] The external rotor permanent magnet variable frequency motor for negative pressure fans provided in this application is first connected to the power supply, which is then connected to the stator windings to provide the required current and voltage. The frequency converter controls the power supply frequency and voltage of the motor to achieve the required speed and output power. Secondly, when the motor is powered on, the stator windings generate a rotating magnetic field, which interacts with the fixed magnetic field of the external rotor. Due to the interaction force of the magnetic fields, the external rotor rotates with the rotation of the stator magnetic field, realizing energy conversion. By precisely controlling the power supply frequency and voltage of the motor through the frequency converter, the motor speed can be adjusted. According to the application requirements, high-speed, low-speed, or variable-speed operation can be achieved to meet the needs of different working conditions.

[0043] This utility model features a novel structure, ingenious design, and simple and convenient operation. This design effectively facilitates the connection between the external rotor permanent magnet motor and the fan frame, and makes it easier to disassemble and maintain the motor. It also increases the service life of the frequency converter, facilitates the maintenance of the external rotor permanent magnet motor, increases the stability of the connection between the device and the frame, and improves the overall quality of the device.

[0044] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An external rotor permanent magnet variable frequency motor for a negative pressure fan, comprising an external rotor permanent magnet motor and a frequency converter located at the rear of the external rotor permanent magnet motor, characterized in that: The frequency converter includes a first housing, a second housing, and a frequency converter assembly. The second housing is detachably connected to the rear side of the first housing. The outer side of the first housing is provided with a connecting groove for fixing the first housing. The front side of the first housing is provided with a positioning groove for positioning the first housing. The frequency converter assembly is installed inside the second housing.

2. The external rotor permanent magnet variable frequency motor for a negative pressure fan according to claim 1, characterized in that: A first fixing ring is fixedly connected to the rear side of the first housing, and a second fixing ring is fixedly connected to the front side of the second housing. Both the first fixing ring and the second fixing ring have multiple first fixing holes, and bolts are threaded into the first fixing holes to fix the first fixing ring and the second fixing ring.

3. The external rotor permanent magnet variable frequency motor for a negative pressure fan according to claim 1, characterized in that: Multiple heat dissipation strips are fixedly connected to the rear side of the second housing.

4. The external rotor permanent magnet variable frequency motor for a negative pressure fan according to claim 1, characterized in that: The external rotor permanent magnet motor includes a first end cover, a housing, and a second end cover. The outer sides of the first end cover, the housing, and the second end cover are provided with multiple second fixing holes. The first end cover and the second end cover are detachably connected to the front and rear sides of the housing through the corresponding second fixing holes.

5. The external rotor permanent magnet variable frequency motor for a negative pressure fan according to claim 1, characterized in that: A connecting block is fixedly connected inside the positioning groove, and a weight reduction groove is provided in the middle of the connecting block.

6. The external rotor permanent magnet variable frequency motor for a negative pressure fan according to claim 1, characterized in that: The interior of the first housing is provided with a plurality of first reinforcing ribs arranged in a circular pattern.

7. The external rotor permanent magnet variable frequency motor for a negative pressure fan according to claim 4, characterized in that: Both the first end cap and the second end cap have multiple second reinforcing ribs arranged in a circular pattern on the side near the housing.

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