Low-loss centrifugal fan

Abstract

The application relates to the field of centrifugal fans, and particularly discloses a low-loss centrifugal fan which comprises a rack, a centrifugal fan installed at one end of the rack, a motor installed at one end of the rack, a blade shaft of the centrifugal fan fixedly connected with an output shaft of the motor, a heat dissipation fan wheel, a support frame installed on the rack and supporting the heat dissipation fan wheel, and an output shaft of the motor having a telescopic clamping piece, and the heat dissipation fan wheel having a corresponding clamping groove; when the rotating speed of the output shaft of the motor reaches a set value, the telescopic clamping piece is clamped into the clamping groove under the influence of centrifugal force, and the heat dissipation fan wheel is driven to rotate. Through the above technical scheme, when the rotating speed of the centrifugal fan is low, the motor is passively cooled; when the rotating speed of the centrifugal fan is high, passive cooling of the motor is insufficient to keep the motor working for a long time, so the telescopic clamping piece is clamped into the clamping groove under the influence of centrifugal force, the heat dissipation fan wheel is driven to actively cool the motor.

Description

Technical Field

[0001] This application relates to the field of centrifugal fans, and in particular to a low-loss centrifugal fan. Background Technology

[0002] Centrifugal fans are machines that use input mechanical energy to increase gas pressure and discharge gas. They are widely used in many fields, including industry and civil applications. When the motor drives the impeller to rotate, the gas in the impeller moves from the center to the edge of the impeller under the action of centrifugal force. In this process, both the gas velocity and pressure are increased. After leaving the impeller and entering the casing, the gas velocity gradually decreases due to the shape of the casing (volute shape), and some of the kinetic energy is converted into pressure energy, finally being discharged from the outlet. At the same time, a low-pressure zone is formed at the center of the impeller, and external gas continuously enters the impeller through the inlet under the action of the pressure difference, thus achieving continuous gas delivery.

[0003] Regarding the aforementioned technologies, the inventors believe that the following defects exist: the motor heats up when the fan rotates at high speed, making it impossible to maintain this state for an extended period. Summary of the Invention

[0004] To improve the heat dissipation of motors, this application provides a low-loss centrifugal fan.

[0005] This application provides a low-loss centrifugal fan using the following technical solution:

[0006] A low-loss centrifugal fan includes a frame, a centrifugal fan mounted at one end of the frame, and a motor mounted at one end of the frame. The output shaft of the motor is fixedly connected to the blade shaft of the centrifugal fan. The fan also includes a cooling impeller that is collinear with the rotation axis of the motor's output shaft. The cooling impeller and the motor's output shaft are spaced apart. A support frame for supporting the cooling impeller is mounted on the frame. The motor's output shaft has a telescopic locking member, and the cooling impeller has a corresponding locking groove. When the motor's output shaft rotates to a set value, the telescopic locking member engages with the locking groove due to centrifugal force, causing the cooling impeller to rotate together.

[0007] By adopting the above technical solution, when the centrifugal fan speed is low, the motor is cooled by passive heat dissipation. When the centrifugal fan speed is high, passive heat dissipation is insufficient to sustain the motor's long-term operation. Therefore, centrifugal force is used to engage the telescopic clip in the slot, driving the cooling fan to actively cool the motor. The cooling fan is generally an axial fan and is made of lightweight materials such as plastic or carbon fiber.

[0008] Optionally, the slot extends from the tangential direction, and the depth of the slot gradually increases.

[0009] Optionally, a magnet is provided at the bottom of the slot, and the telescopic card is attracted to the magnet by magnetism. The magnet can draw the telescopic card into the slot when the radial gap between the telescopic card and the heat dissipation fan is less than a set value.

[0010] By adopting the above technical solution, the magnet is mainly used to allow the telescopic clip to skip the critical point, that is, when the radial gap between the telescopic clip and the cooling fan wheel is reduced to 0, the cooling fan wheel will be damaged by friction with the telescopic clip. Therefore, when the radial gap between the telescopic clip and the cooling fan wheel is close to 0, the telescopic clip directly enters the slot due to the magnet.

[0011] Optionally, sleeves are formed on both sides of the center of the heat dissipation fan, and bearings are provided on the support frame. The outer wall of the sleeve is interference-fitted with the inner ring of the bearing, and one support frame is provided on each side of the heat dissipation fan.

[0012] By adopting the above technical solution, the cooling fan is supported by two support frames, which has good stability, and the bearing arrangement makes the cooling fan rotate more smoothly.

[0013] Optionally, the telescopic locking component includes a locking block and a spring, and a receiving groove for accommodating the locking block is provided in the output shaft of the centrifugal fan, and the spring connects the receiving groove and the locking block.

[0014] By adopting the above technical solution, the spring is used to connect the locking block so that the locking block is in place.

[0015] Optionally, a reinforcing ring is interference-fitted onto the card block. After the card block is inserted into the card slot, the reinforcing ring is located at the opening of the receiving slot, with part of the reinforcing ring inside the receiving slot and part of it extending out of the receiving slot.

[0016] By adopting the above technical solution, the strength of the reinforcing ring is higher than the strength of the block material, and the block is not easy to break when subjected to force.

[0017] Optionally, multiple card blocks are evenly distributed along the circumference, and multiple card slots are set for each card block.

[0018] By adopting the above technical solution, the card block and the card slot are balanced through multiple force points, avoiding excessive force on a single card block that could lead to structural damage.

[0019] Optionally, multiple card blocks are evenly distributed along a spiral line, which extends spirally around the central axis of the motor's output shaft.

[0020] By adopting the above technical solution, the number of receiving grooves on the same circumferential surface will not be too large, as too many receiving grooves will lead to a significant reduction in the strength of the area.

[0021] Optionally, the magnet is a permanent magnet.

[0022] Since the cooling impeller also rotates, there would be interference in the wiring if an electromagnet were used, so a permanent magnet is used instead.

[0023] Optionally, the blade shaft of the centrifugal fan is fitted with a deep groove ball bearing to the frame.

[0024] Deep groove ball bearings have a low coefficient of friction, which allows them to maintain low frictional temperature rise and power consumption during high-speed operation. Compared to sliding bearings, the coefficient of friction for deep groove ball bearings is only 0.001-0.005, while that for sliding bearings is 0.08-0.12. This low coefficient of friction makes deep groove ball bearings perform excellently under high-speed operating conditions, especially under axial loads, where their performance is superior to that of thrust ball bearings. Deep groove ball bearings not only have a low coefficient of friction but also a high limiting speed, simple structure, low manufacturing cost, and are easy to manufacture with high precision.

[0025] In summary, this application includes at least one of the following beneficial technical effects:

[0026] 1. The telescopic clamp mechanism is used to dissipate heat from the motor under high-speed rotation of the centrifugal fan, ensuring stable operation;

[0027] 2. Deep groove ball bearings have a low coefficient of friction and low wear.

[0028] 3. A lightweight cooling fan is used to reduce additional losses at high speeds. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;

[0030] Figure 2 This is a diagram illustrating the connection between the motor's output shaft and the cooling fan. Figure 1 ;

[0031] Figure 3 This is a diagram illustrating the connection between the motor's output shaft and the cooling fan. Figure 2 ;

[0032] Figure 4 This is a schematic diagram showing multiple sets of card blocks and card slots.

[0033] Reference numerals in the attached drawings: 1. Frame; 2. Centrifugal fan; 3. Motor; 4. Cooling impeller; 5. Output shaft; 6. Support frame; 7. Sleeve; 8. Slot; 9. Magnet; 10. Locking block; 11. Spring; 12. Receiving groove; 13. Reinforcing ring. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0035] This application discloses a low-loss centrifugal fan, including a frame, a centrifugal fan mounted at one end of the frame, and a motor mounted at one end of the frame. The output shaft of the motor is fixedly connected to the blade shaft of the centrifugal fan, typically using a coupling. The centrifugal fan is rotatably mounted within the frame, and the blade shaft of the centrifugal fan is fitted with the frame using deep groove ball bearings.

[0036] The low-loss centrifugal fan also includes a cooling impeller whose rotation axis is collinear with that of the motor's output shaft. The cooling impeller is positioned with a clearance between it and the motor's output shaft. A support frame is mounted on the frame to support the cooling impeller. Sleeves are formed on both sides of the center of the cooling impeller, and bearings are mounted on the support frame. The outer wall of the sleeve is interference-fitted with the inner ring of the bearing. One support frame is located on each side of the cooling impeller. The clearance between the sleeve and the motor's output shaft is maintained. It is worth noting that in this design, the cooling impeller is made of plastic, which is lightweight and has minimal impact on the motor's output shaft power. The plastic can be ABS, PP, PVC, PE, PA, PC, or other plastic materials.

[0037] The motor's output shaft has a telescopic locking mechanism, and the cooling fan has a corresponding slot. When the motor's output shaft reaches a set speed, the telescopic locking mechanism engages with the slot due to centrifugal force, causing the cooling fan to rotate as well. This set value can be adjusted based on the actual speed and the motor's cooling performance.

[0038] Specifically, the slot is located on the side wall of the central hole of the cooling fan. The slot extends tangentially, with its depth gradually increasing. A permanent magnet is placed at the bottom of the slot. The telescopic clip is attracted to the magnet, and the magnet can draw the telescopic clip into the slot when the radial gap between the telescopic clip and the cooling fan is less than a set value. The magnet also gradually thickens along the direction of the deepening slot, thus its magnetic attraction gradually strengthens; the thicker the magnet, the stronger the magnetism.

[0039] The telescopic clamp includes a clamping block and a spring. The output shaft of the centrifugal fan has a receiving groove to accommodate the clamping block, and the spring connects the receiving groove and the clamping block.

[0040] A reinforcing ring is interference-fitted onto the locking block. After the locking block is engaged with the slot, the reinforcing ring is located at the opening of the receiving slot, with part of the reinforcing ring inside the receiving slot and part extending out of it. The locking block is made of the same material as the motor's output shaft, typically carbon steel or ductile iron. The reinforcing ring can be made of alloy steel.

[0041] There are two distribution methods for the card blocks. One method involves multiple card blocks evenly distributed along the circumference, with multiple card slots corresponding to each card block. The other method involves multiple card blocks evenly distributed along a spiral line, with the spiral line extending spirally around the central axis of the motor's output shaft. The second method is generally preferred.

[0042] The implementation principle of a low-loss centrifugal fan in this application embodiment is as follows: When the centrifugal fan speed is low, the motor is cooled by passive cooling. When the centrifugal fan speed is high, passive cooling is insufficient to keep the motor running for a long time. Therefore, centrifugal force causes the locking block to engage with the slot, driving the cooling fan wheel to actively cool the motor. At this time, the spring is stretched, and when rotating at low speed, it will retract into the receiving slot.

[0043] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0044] Secondly: The accompanying drawings of the embodiments disclosed in this application only involve the structures involved in the embodiments disclosed in this application. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this application can be combined with each other.

[0045] Finally: The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A low-loss centrifugal fan, comprising a frame, a centrifugal fan mounted at one end of the frame, and a motor mounted at one end of the frame, wherein the output shaft of the motor is fixedly connected to the blade shaft of the centrifugal fan, characterized in that: It also includes a cooling fan that is collinear with the rotation axis of the motor's output shaft. The cooling fan is spaced apart from the motor's output shaft. A support frame for supporting the cooling fan is mounted on the frame. The motor's output shaft has a telescopic locking member, and the cooling fan has a corresponding locking groove. When the motor's output shaft speed reaches a set value, the telescopic locking member is engaged in the locking groove due to centrifugal force, causing the cooling fan to rotate together. The locking groove extends tangentially and gradually increases in depth. A magnet is placed at the bottom of the locking groove, and the telescopic locking member is attracted to the magnet. The magnet can draw the telescopic locking member into the locking groove when the radial gap between the telescopic locking member and the cooling fan is less than a set value. The telescopic locking member includes a locking block and a spring. A receiving groove for accommodating the locking block is opened in the output shaft of the centrifugal fan. The spring connects the receiving groove and the locking block. A reinforcing ring is interference-fitted on the locking block. After the locking block is engaged in the locking groove, the reinforcing ring is located at the opening of the receiving groove, with part of the reinforcing ring inside the receiving groove and part of it extending out of the receiving groove.

2. The low-loss centrifugal fan according to claim 1, characterized in that: Sleeves are formed on both sides of the center of the heat dissipation fan, and bearings are installed on the support frame. The outer wall of the sleeve is interference-fitted with the inner ring of the bearing. One support frame is installed on each side of the heat dissipation fan.

3. The low-loss centrifugal fan according to claim 1, characterized in that: The card blocks are evenly distributed along the circumference, and the card slots are provided for the card blocks in multiple ways.

4. A low-loss centrifugal fan according to claim 1, characterized in that: The card blocks are evenly distributed along a spiral line, which extends spirally around the central axis of the motor's output shaft.

5. A low-loss centrifugal fan according to claim 1, characterized in that: The magnet is a permanent magnet.

6. A low-loss centrifugal fan according to claim 1, characterized in that: The blade shaft of the centrifugal fan is fitted with a deep groove ball bearing to the frame.

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