Shaftless or quasi-shaftless motor driven high-performance centrifugal fan system

Abstract

The invention discloses a shaftless or quasi-shaftless motor driven high-performance centrifugal fan system, and relates to the technical field of centrifugal fans, the shaftless or quasi-shaftless motor driven high-performance centrifugal fan system comprises a fan body, the fan body comprises a fan shell and a motor, the motor is of a flat annular structure, the shaft length is small, and the inner diameter is large; an airflow channel is arranged in the middle of the motor, an impeller is arranged on one side of the motor, the impeller and the fan are both arranged in the fan shell, an air outlet is formed in the fan shell, and the length of the air outlet is the same as the inner diameter of the motor. According to the shaftless or quasi-shaftless motor driven high-performance centrifugal fan system adopting the structure, the power density and efficiency of the motor are guaranteed, the size of the motor is reduced, the aerodynamic performance of the impeller and the electromagnetic performance of the motor are guaranteed, and the performance and reliability of the whole system are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal fans, and in particular to a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor. Background Art

[0002] In the traditional motor-driven fan structure, the motor shaft and internal support structure occupy most of the space of the fan impeller, which not only affects the circulation efficiency of the airflow, but also easily causes noise problems and reduces the overall aerodynamic performance of the system.

[0003] Traditional impeller drive motors usually use motors with large shaft diameters and dense internal structures. Although such designs are simple in structure and low in manufacturing cost, they have many problems in actual use:

[0004] (1) Reduced air intake: Since the motor shaft and internal components occupy most of the space in the impeller air intake channel, the impeller can only take in air from a limited area on the other side, which severely limits the air intake of the impeller. Air can only enter the impeller through a limited path, which increases the air intake resistance in disguise, affecting the air circulation efficiency and the overall performance of the system.

[0005] (2) Increased noise: When the airflow passes through the complex shaft and support structure inside the motor, turbulence will form and a lot of noise will be generated. Especially at high speeds, this noise problem is more significant and directly affects the user experience.

[0006] (3) Poor aerodynamic performance: Due to the complexity of the internal structure, the air generates greater friction resistance when entering and passing through the motor, which reduces the aerodynamic performance of the system. The airflow will encounter multiple reflections and turbulence when passing through the motor, which reduces the aerodynamic efficiency of the impeller and is not conducive to efficient air flow.

[0007] The above problems not only reduce the overall performance of the impeller, but may also lead to a decrease in the efficiency of the entire system. At the same time, such a design may not meet the needs in high-demand application scenarios (such as high-efficiency turbines, large fans, etc.). Therefore, how to design a motor-driven impeller that can improve airflow while reducing noise and improving aerodynamic performance has become a key issue. Summary of the invention

[0008] The purpose of the present invention is to provide a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor to solve the problems raised in the above-mentioned background technology and the problems of noise and insufficient airflow in traditional designs. Among them, quasi-shaftless motors and shaftless motors have broad application prospects in modern industrial and household equipment, and the overall efficiency and user experience are improved by optimizing the design, thus solving technical problems.

[0009] To achieve the above-mentioned objectives, the present invention provides a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor, including a fan body, wherein the fan body includes a fan casing and a motor, and the motor is configured as a flat circular ring structure with a small shaft length and a large inner diameter; an air flow channel is provided at the middle position of the motor, an impeller is provided on one side of the motor, the impeller and the motor are both arranged inside the fan casing, and an exhaust port is provided on the fan casing, and the length of the exhaust port is the same as the inner diameter of the motor.

[0010] Preferably, the motor comprises a quasi-shaftless motor, a small bearing is arranged at the middle position of the quasi-shaftless motor, the small bearing and the quasi-shaftless motor are connected via a support assembly, the support assembly is provided with two groups, one group of the support assemblies connects the small bearing and the stator or fan housing of the quasi-shaftless motor, and the stator is fixedly connected to the fan housing;

[0011] Another group of the supporting components connects the small bearing and the rotor or impeller of the quasi-shaftless motor. The rotor and the impeller are fixedly connected and drive the impeller to rotate around the central axis at the center position of the small bearing.

[0012] Preferably, the support assembly is a plurality of spokes, and the spokes are arranged in a fan-blade structure, a cylindrical structure, or an elliptical column structure.

[0013] Preferably, the motor comprises a shaftless motor, the interior of the shaftless motor is configured as a hollow structure, the rotor of the shaftless motor is connected to the fan housing via a bearing, the rotor is fixedly connected to the impeller, and drives the impeller to rotate around the central axis;

[0014] The stator of the shaftless motor is fixedly connected to the fan housing.

[0015] Preferably, the quasi-shaftless motor and the shaftless motor adopt an outer rotor permanent magnet synchronous motor, or an inner rotor permanent magnet synchronous motor, or an axial flux motor, or an asynchronous motor, or an electrically excited synchronous motor, or a direct current motor.

[0016] Preferably, the outer diameter and the inner diameter of the impeller are the same as the outer diameter and the inner diameter of the quasi-shaftless motor and the shaftless motor.

[0017] Preferably, the impeller is made of light alloy, composite material, or plastic.

[0018] Preferably, the fan body is provided with a sensor and a controller for real-time monitoring and adjusting the operating status of the fan.

[0019] Therefore, the present invention adopts a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor with the above structure, which has the following beneficial effects:

[0020] (1) The high-pole-logarithm fractional-slot concentrated winding motor developed for the fan system has a flat annular geometry and a large hollow shaft, which increases the smoothness of the airflow channel and reduces airflow resistance. The size matching of the impeller and the motor optimizes the airflow path and ensures that the motor does not affect the aerodynamic distribution of the impeller. It meets the aerodynamic shape requirements of the fan. At the same time, it ensures low torque pulsation and motor vibration, low noise, and working efficiency.

[0021] (2) The impeller is connected to the motor rotor and closely matches the volute housing to form a compact structure. The interior of the shaftless motor is completely hollow. The quasi-shaftless motor has only a small amount of aerodynamically designed spoke support structure to reduce airflow noise, improve user experience, and is connected to a small bearing for easy installation and cost savings. The combination of the motor assembly and the volute housing ensures efficient airflow guidance and discharge.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of a shaftless motor of a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to the present invention;

[0024] Figure 2 A schematic structural diagram of a quasi-shaftless motor of a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to the present invention;

[0025] Figure 3 A schematic diagram of the connection between a quasi-shaftless motor and an impeller of a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to the present invention;

[0026] Figure 4 A diagram showing the internal structure of a motor in the form of an axial magnetic flux of a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to the present invention;

[0027] Figure 5 This is a diagram of the internal structure of a motor in the form of an outer rotor of a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to the present invention;

[0028] Figure 6 This is a diagram of the internal structure of a motor in the form of an inner rotor of a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to the present invention;

[0029] Figure numerals: 1. fan casing; 2. impeller; 3. exhaust port; 4. quasi-shaftless motor; 5. small bearing; 6. stator; 7. rotor; 8. center axis; 9. spokes; 10. shaftless motor; 11. air flow channel; 12. stator core; 13. stator winding; 14. rotor permanent magnet; 15. rotor core. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0031] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] Example

[0033] See also Figure 1-6 The present invention provides a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor, including a fan body, the fan body including a fan housing 1 and a motor, the motor is set to a flat circular ring structure, and has a small shaft length and a large inner diameter. An exhaust port 3 is set on the fan housing 1, and the length of the exhaust port 3 is the same as the inner diameter of the motor. The motor has a large inner diameter and a large stator-rotor split ratio and a small axial length and has high efficiency and output capacity in a small volume.

[0034] An air flow channel 11 is provided at the middle position of the motor, and an impeller 2 is provided on one side of the motor, and the impeller 2 is connected to the rotor 7 of the motor and rotates synchronously with the rotor 7. The outer diameter and inner diameter of the impeller 2 are the same as those of the quasi-shaftless motor 4 and the shaftless motor 10, so that the motor does not affect the aerodynamic distribution of the impeller 2, and the impeller 2 is made of light alloy, composite material, or plastic.

[0035] The impeller 2 and the motor are both arranged inside the fan housing 1, and the fan housing 1 is set as a volute structure. The outer edges of the impeller 2 and the motor are closely matched with the inner wall of the fan housing 1 to ensure that the airflow can smoothly pass through the impeller 2 into the volute air chamber of the fan housing 1. Bolts or other fixing devices are used to firmly fix the motor in a preset position in the fan housing 1 to ensure that the motor and the impeller 2 remain stable during operation. The connection between the impeller 2 and the inner wall of the fan housing 1 adopts a sealing design to prevent airflow leakage and ensure the air extraction effect.

[0036] The motor in the present invention includes a quasi-shaftless motor 4 and a shaftless motor 10, wherein the shaftless motor 10 adopts a completely hollow structure, and the quasi-shaftless motor 4 is supported only by a small number of spokes 9. This design allows an air flow channel 11 to exist in the middle of the motor, so that the air flow can smoothly pass through the inside of the motor to reach the impeller 2. The air flow is no longer hindered, and the intake resistance is greatly reduced, thereby significantly increasing the intake volume of the impeller 2.

[0037] The motor includes a quasi-shaftless motor 4, and a small bearing 5 is arranged at the middle position of the quasi-shaftless motor 4. The small bearing 5 is smaller in size and has a lower cost than a large bearing. The small bearing 5 and the quasi-shaftless motor 4 are connected by a support assembly. The support assembly is provided with two groups. One group of support assemblies connects the small bearing 5 and the stator 6 or the fan housing 1 of the quasi-shaftless motor 4, and the stator 6 is fixedly connected to the fan housing 1; the other group of support assemblies connects the small bearing 5 and the rotor 7 or the impeller 2 of the quasi-shaftless motor 4, and the rotor 7 and the impeller 2 are fixedly connected, and the impeller 2 is driven to rotate around the central axis 8 at the center position of the small bearing. The setting of this support assembly allows the airflow driven by the impeller 2 to directly enter the motor through the spokes 9 and reach the impeller 2 when the motor is working.

[0038] The support assembly is a plurality of spokes 9. In order to optimize the airflow, the spokes 9 can be designed according to aerodynamics into a fan-blade structure with excellent flow-guiding performance, or a small cylindrical structure, or an elliptical cylindrical structure, or other special-shaped structures with similar fluid dynamics. By optimizing the shape of the spokes 9, the noise during operation can be further reduced and the quiet performance of the system can be improved. In addition, the design with fewer support components reduces air resistance and enhances the aerodynamic performance of the system. The optimized airflow path and reduced internal obstructions allow air to pass through the impeller 2 more efficiently, improving the overall aerodynamic efficiency of the system. The support assembly can also adopt an integrally formed annular support structure, a multi-point array support structure or an adjustable support structure, which can provide higher structural strength and stability while maintaining aerodynamic efficiency.

[0039] The motor includes a shaftless motor 10, the interior of the shaftless motor 10 is set as a hollow structure, and the rotor 7 of the shaftless motor 10 is connected to the fan housing 1 through a bearing component, wherein the bearing assembly can adopt a liquid bearing, a magnetic bearing, an air bearing, etc. to adapt to different application requirements and working environments. The rotor 7 is fixedly connected to the impeller 2 and drives the impeller 2 to rotate around the central axis 8; the stator 6 of the shaftless motor 10 is fixedly connected to the fan housing 1. Due to the reduction of the internal shaft and the supporting components, the friction and turbulence of the airflow when passing through the airflow channel 11 are greatly reduced, thereby significantly reducing the noise.

[0040] The present invention adopts high pole logarithm fractional slot concentrated winding to effectively reduce the high-order harmonic content in the quasi-shaftless motor 4 and the shaftless motor 10, so that the magnetic field distribution between the stator 6 and the rotor 7 is more uniform, and the torque pulsation is further reduced, thereby reducing the vibration and noise of the motor. Therefore, this design not only provides excellent aerodynamic performance when driving the impeller, but also has excellent electromagnetic performance. The quasi-shaftless motor 4 and the shaftless motor 10 adopt an outer rotor permanent magnet synchronous motor, or an inner rotor permanent magnet synchronous motor, or an axial flux motor, or an asynchronous motor, or an electrically excited synchronous motor, or a DC motor. The motor permanent magnet magnetic steel can be selected from motor magnetic steel materials such as neodymium iron boron permanent magnets, ferrite permanent magnets, samarium cobalt permanent magnets, and aluminum nickel cobalt permanent magnets. The motor winding adopts conductive materials such as copper or aluminum. The rotor core and stator core of the motor adopt silicon steel sheets. The magnetic flux path of the silicon steel sheet is shorter and more concentrated, which improves the utilization rate of the silicon steel sheet, thereby improving the efficiency of the motor.

[0041] Sensors and controllers are provided on the fan body. The sensors are temperature sensors and Hall sensors arranged in the stator slots of the motor, and current sensors and voltage sensors arranged in the three-phase windings of the motor. The controller is a position encoder arranged at the central axis 8 of the motor, which is used to monitor and adjust the operating status of the fan in real time.

[0042] The optimized structural parameters obtained through experimental design are as follows:

[0043] The outer diameter of the impeller 2 is 128 mm, the inner diameter is 100 mm, the impeller 2 is welded or embedded in the rotor 7, and the impeller is directly driven by the rotor 7 to rotate synchronously. The impeller 2 is made of aluminum alloy material, with 15 blades, a blade width of 10 mm, and a thickness of 2 mm. The size of the impeller 2 does not exceed the size of the fan housing 1.

[0044] The shaftless motor 10 or the quasi-shaftless motor 4 adopts an outer rotor type, such as Figure 4As shown, it includes a stator core 12, a stator winding 13, a rotor permanent magnet 14 and a rotor core 15 arranged outside the stator winding 13. The number of poles is 38 poles or 40 poles, the number of slots is 36 slots, the rotor magnetic steel adopts FB9N ferrite permanent magnet, the pole arc coefficient is 160deg, and the silicon steel sheet adopts the grade of dw310_50. The slot depth is 6mm and the tooth width is 2.3mm.

[0045] The inner diameter of the outer rotor motor is 100mm and the outer diameter is 128mm. The thickness of the rotor 7 is 5mm, and the ratio of the stator 6 to the rotor 7 is 0.967; the rated power is 50W, the rated speed is 1600rpm, and the rated point efficiency is 90%. The motor is powered by a 311V DC bus voltage and a three-phase inverter. The motor is set in a fan casing 1 with an outer diameter of 130m and an inner diameter of 98mm. The fan casing 1 is set in the form of a volute, with an air inlet with a diameter of 98mm on both sides, and the size of the exhaust port 3 is 90mm×120mm. The casing material is made of stainless steel with a thickness of 1.2~2.5mm or high-quality plastic with a thickness of 3~5mm.

[0046] In addition, the motor can also adopt inner rotor type or axial flux type, such as Figure 3 and Figure 5 As shown. According to the specific fan geometry and installation requirements, change the form and size of the motor.

[0047] For the quasi-shaftless motor 4, the stator 6 is fixed to the fan housing 1 by bolts or welding, and the small bearing 5 is fixed at the center of the motor by 4 to 6 spokes 9. The material of the spokes 9 is carbon steel, stainless steel or aluminum alloy, with a diameter of 2 mm, and is evenly distributed in the housing. One end of the two groups of spokes 9 is welded to the small bearing 5, and the other end is welded to the stator 6 and the rotor 7 respectively.

[0048] For the shaftless motor 10, the stator 6 is fixed to the fan housing 1 by bolts or welding, and the rotor 7 is directly connected to the fan housing 1 by a large bearing, so that the rotor 7 rotates around the central axis 8. The rotor 7 is connected to the impeller 2 and drives the impeller 2 to rotate. The center of the shaftless motor 10 is completely hollow.

[0049] After installation, the oil fume airflow enters through the airflow channel 11 in the center of the impeller 2 , and the centrifugal force generated by the rotation of the impeller 2 discharges the airflow outward along the inner wall of the fan housing 1 , and finally discharges the air to the outside through the exhaust port 3 .

[0050] Therefore, the present invention adopts a high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor with the above structure, which not only ensures the power density and efficiency of the motor, but also reduces the size of the motor, ensures the aerodynamic performance of the impeller and the electromagnetic performance of the motor, and greatly improves the performance and reliability of the overall system.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor, characterized in that: The invention comprises a fan body, which comprises a fan casing and a motor. The motor is arranged to be a flat annular structure with a small shaft length and a large inner diameter. An air flow channel is arranged at the middle position of the motor, an impeller is arranged on one side of the motor, the impeller and the motor are arranged inside the fan casing, an exhaust port is arranged on the fan casing, and the length of the exhaust port is the same as the inner diameter of the motor.

2. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to claim 1, characterized in that: The motor comprises a quasi-shaftless motor, a small bearing is arranged at the middle position of the quasi-shaftless motor, the small bearing and the quasi-shaftless motor are connected via a support assembly, the support assembly is provided with two groups, one group of the support assemblies connects the small bearing and the stator or fan housing of the quasi-shaftless motor, and the stator is fixedly connected to the fan housing; Another group of the supporting components connects the small bearing and the rotor or impeller of the quasi-shaftless motor. The rotor and the impeller are fixedly connected and drive the impeller to rotate around the central axis at the center position of the small bearing.

3. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to claim 2, characterized in that: The support assembly is a plurality of spokes, and the spokes are arranged in a fan-blade structure, a cylindrical structure, or an elliptical column structure.

4. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to claim 1, characterized in that: The motor comprises a shaftless motor, the interior of the shaftless motor is arranged as a hollow structure, the rotor of the shaftless motor is connected to the fan housing through a bearing, the rotor is fixedly connected to the impeller, and drives the impeller to rotate around the central axis; The stator of the shaftless motor is fixedly connected to the fan housing.

5. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to claim 2 or 4, characterized in that: The quasi-shaftless motor and the shaftless motor adopt an outer rotor permanent magnet synchronous motor, or an inner rotor permanent magnet synchronous motor, or an axial flux motor, or an asynchronous motor, or an electrically excited synchronous motor, or a direct current motor.

6. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to claim 2 or 4, characterized in that: The outer diameter and the inner diameter of the impeller are the same as those of the quasi-shaftless motor and the shaftless motor.

7. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to claim 1, characterized in that: The impeller is made of light alloy, composite material or plastic.

8. A high-performance centrifugal fan system driven by a shaftless or quasi-shaftless motor according to claim 1, characterized in that: The fan body is provided with a sensor and a controller for real-time monitoring and adjusting the operating state of the fan.

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