Plastic-sealed brushless direct-current fan

Abstract

The utility model discloses a kind of plastic package brushless DC fan, it includes lower volute, flange nut, gasket, impeller, shell sealing strip, upper volute, rubber bushing, lubricating grease, first self-tapping screw, brushless DC motor, nameplate, second self-tapping screw, air outlet sealing strip and two-dimensional code nameplate.Lower volute and upper volute are riveted connection by flange nut, and deformation resistance is enhanced;Rubber bushing and gasket reduce vibration noise;Shell sealing strip and air outlet sealing strip ensure sealing performance;Two-dimensional code nameplate facilitates information query.The application can effectively prevent shell deformation, improve assembly efficiency, reduce resonance noise, and is suitable for high-frequency vibration working conditions such as drying machine and other equipment.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and in particular to a plastic-encapsulated brushless DC fan. Background Technology

[0002] In modern household appliances, brushless DC fans are widely used in applications requiring high-frequency vibration, such as dryers, due to their high efficiency, low noise, and long lifespan. However, existing brushless DC fans still face several technical challenges in practical applications. For example, the casing structure of traditional fans is prone to deformation under high temperature or high-frequency vibration, leading to performance degradation or even failure. Furthermore, current fan installation methods typically employ bolted connections or other detachable structures. This method is not only inefficient but also prone to loosening under high-frequency vibration, further impacting equipment stability and reliability. Simultaneously, the inevitable resonance noise generated during fan operation negatively affects the user experience. Therefore, designing a brushless DC fan that effectively prevents casing deformation, improves installation efficiency, and reduces resonance noise has become a critical technical challenge for those skilled in the art. Utility Model Content

[0003] The purpose of this utility model is to provide a plastic-encapsulated brushless DC fan that solves the problems mentioned in the background art.

[0004] This utility model is implemented as follows: a plastic-encapsulated brushless DC fan includes a lower volute, flange nut, washer, impeller, housing sealing strip, upper volute, rubber bushing, lubricant, first self-tapping screw, brushless DC motor, nameplate, second self-tapping screw, air outlet sealing strip, and QR code nameplate. Wherein:

[0005] The lower volute is the bottom outer shell of the fan, made of high-strength engineering plastic, which has the ability to resist deformation. Furthermore, the inner wall of the lower volute is provided with a reinforcing rib structure, which is evenly distributed along the circumference of the lower volute to enhance its rigidity and distribute vibration load, thereby avoiding shell deformation caused by high-frequency vibration.

[0006] The flange nut is used to secure the connection between the lower and upper volute housings, and it is installed by riveting. Specifically, the outer edge of the flange nut has an annular boss that matches a corresponding groove on the lower volute housing. The flange nut and the lower volute housing are riveted together using a stamping device. This connection method eliminates the risk of loosening that may exist with traditional threaded connections and improves assembly efficiency.

[0007] Furthermore, the washer, made of elastic rubber, is positioned between the flange nut and the lower volute. The washer's thickness is precisely calculated to ensure appropriate compression during flange nut riveting, thus providing a cushioning effect. Additionally, the washer's outer diameter is slightly larger than the flange nut's outer diameter, forming a sealing surface to prevent external dust from entering the connection.

[0008] The impeller is the core component of the fan, and its blades are designed with optimized hydrodynamics. Specifically, the leading edge of the blades adopts an arc-shaped transition structure, while the trailing edge is designed with a serrated shape to reduce the probability of airflow separation. Furthermore, the blade surface is coated with a drag-reducing coating made of polytetrafluoroethylene (PTFE), which effectively reduces air resistance, increases airflow and air pressure, and reduces operating noise.

[0009] Specifically, the housing sealing strip is installed at the joint between the lower and upper volutes, and its cross-sectional shape is "U". Both sides of the housing sealing strip are embedded in the sealing grooves of the lower and upper volutes, respectively, achieving a tight connection through an interference fit. The depth of the sealing groove is in a 1:1.2 ratio to the thickness of the housing sealing strip to ensure that the sealing strip fully fills the joint after assembly, preventing air leakage.

[0010] The upper volute is the top outer shell of the fan, and its inner wall is also equipped with a reinforcing rib structure. The position of the reinforcing ribs corresponds to that of the lower volute to form an overall support frame. Furthermore, a circular mounting hole is provided on the top of the upper volute to accommodate the output shaft of the brushless DC motor. The diameter of the mounting hole is slightly larger than the diameter of the motor shaft to allow for thermal expansion.

[0011] Furthermore, the rubber bushing is installed between the brushless DC motor shaft and the impeller. Its inner hole is connected to the motor shaft via an interference fit, and its outer cylindrical surface is fixed to the center hole of the impeller via a keyway structure. The wall thickness of the rubber bushing is optimized to balance vibration damping and transmission efficiency. Specifically, the ratio of the rubber bushing wall thickness to the motor shaft diameter is 0.15:1, which can effectively absorb vibration while maintaining sufficient rigidity.

[0012] The grease, which is filled into the motor bearing, comprises base oil, thickener, and antioxidant. Furthermore, the grease has a viscosity index of 150, enabling it to maintain stable lubrication performance under both high and low temperature conditions, thereby reducing frictional resistance and extending the motor's service life.

[0013] Specifically, the first self-tapping screw is used to secure the connection between the brushless DC motor and the upper volute. The first self-tapping screw has a thread angle of 60° and its tip is designed to be tapered for quick insertion into the mounting hole of the upper volute. Furthermore, the head of the first self-tapping screw is provided with a Phillips head for easy tightening using standard tools.

[0014] The brushless DC motor, serving as the power source for the fan, employs a distributed winding design in its stator windings to improve electromagnetic conversion efficiency. Furthermore, the brushless DC motor's housing surface is equipped with heat dissipation fins, each 3mm high and 2mm spaced, to enhance heat dissipation performance. Additionally, the motor's control circuit board integrates an electromagnetic compatibility filter to reduce electromagnetic interference affecting surrounding equipment.

[0015] Furthermore, the nameplate, made of high-temperature resistant polycarbonate, is mounted on the fan casing. It is fixed to a designated position on the upper volute using a hot-melt welding process to ensure it will not detach during long-term use. The nameplate displays the fan's model, specifications, power, and production date for easy user identification and maintenance.

[0016] The second self-tapping screw is used to secure the connection between the air outlet sealing strip and the upper volute, and its structure is the same as the first self-tapping screw. Furthermore, the installation position of the second self-tapping screw has been optimized to avoid excessive compression of the air outlet sealing strip, which would affect the sealing performance.

[0017] The air outlet sealing strip is installed at the air outlet of the fan and is made of silicone rubber, which has good weather resistance and elasticity. The cross-sectional shape of the air outlet sealing strip is rectangular, and its width matches the width of the air outlet to ensure complete coverage of the joint area.

[0018] Specifically, the QR code nameplate is mounted on the fan housing, and its surface is coated with a scratch-resistant coating to protect the QR code pattern from wear. The QR code nameplate is fixed to a designated position on the upper volute using double-sided tape. Users can scan the QR code to obtain detailed information about the fan and its operating instructions, thereby improving maintenance efficiency.

[0019] The beneficial effects of this invention are as follows: By optimizing the design of the lower and upper volutes, the strength and deformation resistance of the fan casing are significantly improved. Furthermore, the use of riveting to install the flange nuts not only improves assembly efficiency but also eliminates the risk of loosening. The specific design of the rubber bushings, washers, and casing sealing strips reduces resonance noise and improves the smoothness of fan operation. The installation of casing and outlet sealing strips ensures no air leakage during fan operation, thereby improving work efficiency. In addition, the introduction of a QR code nameplate provides users with a convenient way to query information, further improving maintenance efficiency.

[0020] In summary, the encapsulated brushless DC fan of this invention has significant advantages in structural design, assembly process and operating performance, and is particularly suitable for use in equipment under high-frequency vibration conditions, such as dryers. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0022] The attached figures are labeled as follows:

[0023] 1. Lower volute; 2. Flange nut; 3. Washer; 4. Impeller; 5. Housing sealing strip; 6. Upper volute; 7. Rubber bushing; 8. Lubricating grease; 9. First self-tapping screw; 10. Brushless DC motor; 11. Nameplate; 12. Second self-tapping screw; 13. Air outlet sealing strip; 14. QR code nameplate. Detailed Implementation

[0024] This utility model provides a specific implementation method for a plastic-encapsulated brushless DC fan, in conjunction with the attached... Figure 1 The accompanying diagrams and reference numerals are explained in detail. Figure 1 The diagram shows the overall structure of this utility model, with the following components labeled as follows: 1. Lower volute; 2. Flange nut; 3. Washer; 4. Impeller; 5. Housing sealing strip; 6. Upper volute; 7. Rubber bushing; 8. Lubricating grease; 9. First self-tapping screw; 10. Brushless DC motor; 11. Nameplate; 12. Second self-tapping screw; 13. Air outlet sealing strip; 14. QR code nameplate.

[0025] In practical implementation, the lower volute 1, serving as the bottom outer shell of the fan, is made of high-strength engineering plastic, with a reinforcing rib structure designed on its inner wall. These reinforcing ribs are evenly distributed circumferentially along the lower volute 1 to enhance rigidity and distribute vibration loads. Finite element analysis has verified that this reinforcing rib design can reduce deformation under high-frequency vibration conditions to less than 30% of the original design, effectively preventing shell deformation. Simultaneously, the outer edge of the lower volute 1 has grooves to match the annular boss of the flange nut 2. The flange nut 2 is riveted to the lower volute 1 using a stamping device, forming an integrated connection structure. This riveting method not only improves assembly efficiency but also eliminates the risk of loosening that may exist with traditional threaded connections. In actual production, 50 flange nuts 2 can be riveted per minute, approximately three times more efficient than traditional threaded installation methods.

[0026] Furthermore, a washer 3 is positioned between the flange nut 2 and the lower volute 1, and its material is elastic rubber. The thickness of the washer 3 is precisely calculated to ensure appropriate compression during the riveting process of the flange nut 2, thus providing a buffering effect. The outer diameter of the washer 3 is slightly larger than the outer diameter of the flange nut 2, forming a sealing surface that prevents external dust from entering the connection. In experimental testing, this sealing structure can withstand dust concentrations of 10 mg / m³. 3 It can operate continuously for 1000 hours in a suitable environment without dust intrusion.

[0027] Impeller 4 is the core component of the fan. Its blades are designed with optimized fluid dynamics, featuring an arc-shaped transition structure at the leading edge and a serrated trailing edge to reduce the probability of airflow separation. The blade surface is coated with a polytetrafluoroethylene (PTFE) drag-reducing coating with a thickness controlled between 0.1mm and 0.15mm. Wind tunnel testing has verified that this design can increase airflow by 15% while reducing operating noise by more than 3dB. The central hole of impeller 4 is fixed to the outer cylindrical surface of rubber bushing 7 via a keyway structure. The inner hole of rubber bushing 7 is connected to the output shaft of brushless DC motor 10 via an interference fit. The ratio of the wall thickness of rubber bushing 7 to the motor shaft diameter is 0.15:1, which ensures transmission efficiency while absorbing vibration energy, thereby reducing resonance noise.

[0028] The housing sealing strip 5 is installed at the joint between the lower volute 1 and the upper volute 6. Its cross-sectional shape is "U," with both sides embedded in the sealing grooves of the lower volute 1 and the upper volute 6 respectively, achieving a tight connection through an interference fit. The depth of the sealing groove is in a 1:1.2 ratio to the thickness of the housing sealing strip 5, ensuring that the sealing strip 5 fully fills the joint after assembly. In practical applications, this sealing structure can withstand an internal pressure of 0.5 MPa without leakage. The inner wall of the upper volute 6 also has a reinforcing rib structure, and the position of the reinforcing ribs corresponds to that of the lower volute 1, forming an integral support frame. The diameter of the circular mounting hole at the top of the upper volute 6 is 0.2 mm larger than the output shaft diameter of the brushless DC motor 10 to allow for thermal expansion and avoid assembly stress caused by temperature changes.

[0029] The brushless DC motor 10 serves as the power source for the fan. Its stator windings employ a distributed winding design, achieving an electromagnetic conversion efficiency of over 92%. The motor housing surface is equipped with heat dissipation fins, 3mm high and 2mm spaced, which, through natural convection, meet the motor's temperature rise requirements at rated power. The grease 8 filling the motor bearings contains base oil, thickener, and antioxidant, with a viscosity index of 150, maintaining stable lubrication performance within a temperature range of -20℃ to 120℃. The brushless DC motor 10 is fixed to the upper volute 6 by a first self-tapping screw 9. The first self-tapping screw 9 has a 60° thread angle and a tapered tip for quick insertion into the mounting hole. During assembly, the tightening torque of each screw is controlled between 1.2Nm and 1.5Nm to ensure connection strength.

[0030] Nameplate 11 is made of high-temperature resistant polycarbonate material and is fixed to a designated position on the upper volute 6 using a hot-melt welding process. The information marked on nameplate 11 includes the fan model, specifications, power, and production date. This information is formed using laser engraving to ensure it will not fade or peel off during long-term use. A QR code nameplate 14 is installed on the other side of the upper volute 6. Its surface is coated with a scratch-resistant coating to protect the QR code pattern from wear. QR code nameplate 14 is fixed with double-sided tape. Users can scan the QR code to obtain detailed fan information and operating instructions, thereby improving maintenance efficiency.

[0031] The outlet sealing strip 13 is installed at the air outlet of the fan and is made of silicone rubber, which has good weather resistance and elasticity. The cross-sectional shape of the outlet sealing strip 13 is rectangular, and its width matches the width of the air outlet to ensure complete coverage of the joint area. The second self-tapping screw 12 is used to fix the connection between the outlet sealing strip 13 and the upper volute 6, and its structure is the same as that of the first self-tapping screw 9. The installation position of the second self-tapping screw 12 is optimized to avoid excessive compression of the outlet sealing strip 13, which would affect the sealing performance. In actual testing, this sealing structure can maintain a stable sealing effect at a wind speed of 10m / s.

[0032] The operating principle of the fan is as follows: S1 The brushless DC motor 10 is started, and the motor output shaft drives the rubber bushing 7 to rotate. The rubber bushing 7 drives the impeller 4 to rotate through the keyway structure. S2 When the impeller 4 rotates, air enters from the fan inlet, is accelerated by the impeller 4, and is discharged from the outlet. S3 Under high-frequency vibration conditions, the reinforcing ribs of the lower volute 1 and the upper volute 6 work together to disperse the vibration load and prevent the outer shell from deforming. S4 The rubber bushing 7 absorbs the vibration energy transmitted by the motor shaft, reducing resonance noise. S5 The housing sealing strip 5 and the outlet sealing strip 13 ensure that there is no air leakage during the operation of the fan, improving working efficiency.

[0033] In specific applications within the dryer, the fan is installed in the equipment's ventilation system to provide a stable airflow. During operation, the brushless DC motor 10 adjusts its speed according to signals from the control system to meet airflow requirements under different operating conditions. The fan's resistance to deformation and its vibration-damping design enable it to operate stably for extended periods in the high-frequency vibration environment of the dryer, achieving a mean time between failures (MTBF) of over 20,000 hours. Users can quickly access fan maintenance information via the QR code nameplate 14, simplifying equipment management processes.

[0034] In summary, this utility model significantly improves the fan's resistance to deformation, assembly efficiency, and operational stability through optimized design of the lower volute 1 and upper volute 6, riveting installation of the flange nut 2, and the inclusion of a rubber bushing 7, washer 3, and housing sealing strip 5. The housing sealing strip 5 and outlet sealing strip 13 ensure no air leakage during operation, thereby improving work efficiency. The introduction of the QR code nameplate 14 provides users with a convenient way to query information, further improving maintenance efficiency. This utility model's encapsulated brushless DC fan has significant advantages in structural design, assembly process, and operational performance, making it particularly suitable for equipment operating under high-frequency vibration conditions, such as dryers.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A plastic-encapsulated brushless DC fan, comprising: The components include a lower volute (1), a flange nut (2), a washer (3), an impeller (4), a housing sealing strip (5), an upper volute (6), a rubber bushing (7), a lubricant (8), a first self-tapping screw (9), a brushless DC motor (10), a nameplate (11), a second self-tapping screw (12), an air outlet sealing strip (13), and a QR code nameplate (14). The lower volute (1) has a reinforcing rib structure evenly distributed along the circumference on its inner wall. The flange nut (2) is installed on the lower volute (1) by riveting. The washer (3) is placed between the flange nut (2) and the lower volute (1). The housing sealing strip (5) is installed at the joint between the lower volute (1) and the upper volute (6). The rubber bushing (7) is installed between the output shaft of the brushless DC motor (10) and the impeller (4). Its inner hole is connected to the motor shaft by an interference fit. The outer cylindrical surface is fixed to the center hole of the impeller (4) by a keyway structure.

2. The encapsulated brushless DC fan as described in claim 1, characterized in that: The flange nut (2) has an annular boss on its outer edge, which matches the corresponding groove on the lower volute (1).

3. The encapsulated brushless DC fan as described in claim 2, characterized in that: The washer (3) is made of elastic rubber material, and its outer diameter is larger than that of the flange nut (2).

4. The encapsulated brushless DC fan as described in claim 1, characterized in that: The impeller (4) blades have an arc-shaped transition structure at the leading edge and a serrated trailing edge.

5. The encapsulated brushless DC fan as described in claim 4, characterized in that: The impeller (4) blades are coated with a polytetrafluoroethylene drag-reducing coating.

6. The encapsulated brushless DC fan as described in claim 1, characterized in that: The shell sealing strip (5) has a "U" shaped cross section, and its two sides are respectively embedded in the sealing grooves of the lower volute (1) and the upper volute (6).

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