Low-loss centrifugal fan

Abstract

The invention relates to the field of centrifugal fans, and particularly discloses a low-loss centrifugal fan which comprises a rack, a centrifugal fan body installed at one end of the rack, a motor installed at one end of the rack and a heat dissipation wind wheel, an output shaft of the motor is fixedly connected with a blade shaft of the centrifugal fan body, and the heat dissipation wind wheel and the output shaft of the motor are arranged in a spaced mode. A supporting frame for supporting the heat dissipation wind wheel is installed on the support, an output shaft of the motor is provided with a telescopic clamping piece, the heat dissipation wind wheel is provided with a corresponding clamping groove, and 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 to drive the heat dissipation wind wheel to rotate together. By the adoption of the technical scheme, when the rotating speed of the centrifugal fan is low, motor heat dissipation is achieved in a passive heat dissipation mode, and when the rotating speed of the centrifugal fan is high, passive heat dissipation of the motor is insufficient so that the motor can work for a long time; therefore, the telescopic clamping piece is clamped into the clamping groove through centrifugal force to drive the heat dissipation wind wheel to actively dissipate heat of the motor.

Description

Technical Field

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

[0002] A centrifugal fan is a machine that relies on input mechanical energy to increase gas pressure and deliver gas. It is widely used in many fields such as industry and civil use. When the motor drives the impeller to rotate, the gas in the impeller moves from the center of the impeller to the edge of the impeller under the action of centrifugal force. In this process, the speed and pressure of the gas are increased. After the gas leaves the impeller and enters the casing, due to the shape of the casing (volute shape), the flow rate of the gas gradually decreases, and part of the kinetic energy is converted into pressure energy, and finally discharged from the air outlet. At the same time, a low-pressure area is formed in the center of the impeller, and the external gas continuously enters the impeller through the air inlet under the action of the pressure difference, thereby realizing the continuous delivery of gas.

[0003] With respect to the above-mentioned related technologies, the inventors believe that there are the following defects: when the fan rotates at high speed, the motor generates heat and cannot be maintained for a long time. Summary of the invention

[0004] In order to improve the problem of motor heat dissipation, the present application provides a low-loss centrifugal fan.

[0005] The low-loss centrifugal fan provided in this application adopts the following technical solution:

[0006] A low-loss centrifugal fan comprises a frame, a centrifugal fan installed at one end of the frame, and a motor installed at one end of the frame, wherein the output shaft of the motor is fixedly connected to the blade shaft of the centrifugal fan, and also comprises a heat dissipation fan wheel which is colinear with the rotation axis of the output shaft of the motor, a gap is set between the heat dissipation fan wheel and the output shaft of the motor, a support frame for supporting the heat dissipation fan wheel is installed on the bracket, the output shaft of the motor has a telescopic clamp, and the heat dissipation fan wheel has a corresponding clamping slot, when the output shaft speed of the motor reaches a set value, the telescopic clamp is clamped into the clamping slot under the influence of centrifugal force to drive the heat dissipation fan wheel to rotate together.

[0007] By adopting the above technical solution, when the centrifugal fan speed is low, the motor heats up by passive heat dissipation. When the centrifugal fan speed is high, the motor passive heat dissipation is not enough to keep the motor working for a long time by its own heat dissipation. Therefore, the centrifugal force is used to clamp the telescopic card into the card slot to drive the heat dissipation wind wheel to actively dissipate the heat of the motor. The heat dissipation wind wheel is generally an axial wind wheel and is made of lightweight materials such as plastic, carbon fiber, etc.

[0008] Optionally, the slot extends from the tangent 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 magnetically attracted to the magnet. The magnet can suck the telescopic card into the slot when the radial gap between the telescopic card and the heat dissipation wind wheel is smaller than a set value.

[0010] By adopting the above technical solution, the magnet is mainly set to allow the telescopic card to jump over the critical point, that is, when the radial gap between the telescopic card and the heat dissipation wind wheel is reduced to 0, the heat dissipation wind wheel will be damaged by friction with the telescopic card. Therefore, when the radial gap between the telescopic card and the heat dissipation wind wheel is close to 0, the telescopic card directly enters the card slot due to the magnet.

[0011] Optionally, sleeves are formed on both sides of the center of the heat dissipation wind wheel, a bearing is arranged inside the support frame, the outer wall of the sleeve is interference fit with the inner ring of the bearing, and one support frame is arranged on each side of the heat dissipation wind wheel.

[0012] By adopting the above technical solution, the heat dissipation wind wheel is supported by two support frames, and its stability is good. The setting of the bearing makes the heat dissipation wind wheel rotate more smoothly.

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

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

[0015] Optionally, a reinforcement ring is interference-fitted on the clamping block, and the reinforcement ring is located at the opening of the receiving groove after the clamping block is inserted into the clamping groove, and the reinforcement ring is partially located in the receiving groove and partially extends out of the receiving groove.

[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, the card blocks are evenly distributed in a circumferential direction, and multiple card slots are provided corresponding to the card blocks.

[0018] By adopting the above technical solution, the card block and the card slot are balanced through multiple force points, thereby preventing a single card block from being subjected to excessive force and causing structural damage.

[0019] Optionally, a plurality of the clamping blocks are evenly distributed along the spiral line, and the spiral line extends spirally around the central axis of the output shaft of the motor.

[0020] By adopting the above technical solution, the number of receiving grooves arranged 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 heat dissipation impeller also rotates, if an electromagnet is installed, there will be interference in the wiring, so a permanent magnet is used.

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

[0024] Deep groove ball bearings have a small friction coefficient, which allows them to maintain low friction temperature rise and power consumption when running at high speeds. Compared with sliding bearings, the friction coefficient of deep groove ball bearings is only 0.001-0.005, while the friction coefficient of sliding bearings is 0.08-0.12. This low friction coefficient characteristic enables deep groove ball bearings to perform well under high-speed operating conditions, especially when subjected to axial loads, their performance is better than that of thrust ball bearings. Deep groove ball bearings not only have a small friction coefficient, but also have a high limit speed, a simple structure, low manufacturing cost, and are easy to achieve high manufacturing precision.

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

[0026] 1. The motor is cooled by telescopic clamps when the centrifugal fan rotates at high speed, and the operation is stable;

[0027] 2. Deep groove ball bearings have low friction coefficient and low loss;

[0028] 3. Use lightweight heat dissipation fan to reduce additional losses at high speeds. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0030] Figure 2 This is a schematic diagram of the coordination between the motor output shaft and the cooling fan wheel. Figure 1 ;

[0031] Figure 3 This is a schematic diagram of the coordination between the motor output shaft and the cooling fan wheel. Figure 2 ;

[0032] Figure 4 It is a schematic diagram of multiple distribution groups of card blocks and card slots.

[0033] Figure numerals: 1, frame; 2, centrifugal fan; 3, motor; 4, heat dissipation fan wheel; 5, output shaft; 6, support frame; 7, sleeve; 8, slot; 9, magnet; 10, block; 11, spring; 12, receiving groove; 13, reinforcement ring. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-4 This application is described in further detail.

[0035] The embodiment of the present application discloses 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, and the fixing here is generally performed by a coupling. The centrifugal fan is rotatably mounted in the frame, and the blade shaft of the centrifugal fan is matched with the frame by a deep groove ball bearing.

[0036] The low-loss centrifugal fan also includes a heat dissipation fan wheel that is colinear with the rotation axis of the output shaft of the motor, and a gap is set between the heat dissipation fan wheel and the output shaft of the motor. A support frame for supporting the heat dissipation fan wheel is installed on the bracket, and sleeves are formed on both sides of the center of the heat dissipation fan wheel. Bearings are arranged inside the support frame, and the outer wall of the sleeve and the inner ring of the bearing are interference fit. One support frame is arranged on each side of the heat dissipation fan wheel. A gap is set between the sleeve and the output shaft of the motor. It should be particularly noted that in this solution, the heat dissipation fan wheel is made of plastic, which is light in weight and has little effect on the power of the output shaft of the motor. The plastic can be ABS, PP, PVC, PE, PA, PC and other plastic materials.

[0037] The output shaft of the motor has a telescopic clamp, and the heat dissipation fan wheel has a corresponding slot. When the output shaft speed of the motor reaches the set value, the telescopic clamp is affected by the centrifugal force and is inserted into the slot to drive the heat dissipation fan wheel to rotate together. The set value here can be set according to the actual speed and the heat dissipation of the motor.

[0038] Specifically, the card slot is opened on the side wall of the center hole of the heat dissipation wind wheel. The card slot extends from the tangent direction, and the depth of the card slot gradually deepens. A magnet is set at the bottom of the card slot. The magnet is a permanent magnet. The telescopic card and the magnet are magnetically attracted to each other. The magnet can suck the telescopic card into the card slot when the radial gap between the telescopic card and the heat dissipation wind wheel is less than a set value. The magnet also gradually becomes thicker in the direction where the card slot gradually deepens, so its magnetic attraction is also gradually strengthened. The thicker the thickness, the stronger the magnetism.

[0039] The telescopic clamp comprises a clamp block and a spring. A receiving groove for receiving the clamp block is arranged in the output shaft of the centrifugal fan. The spring connects the receiving groove and the clamp block.

[0040] A reinforcing ring is interference fit on the block. After the block is inserted into the slot, the reinforcing ring is located at the opening of the receiving slot, and part of the reinforcing ring is located in the receiving slot and part of the reinforcing ring is extended out of the receiving slot. The material of the block is the same as that of the output shaft of the motor, generally carbon steel or ductile iron. The reinforcing ring can be made of alloy steel.

[0041] There are two ways to distribute the blocks. One is to evenly distribute multiple blocks along the circumferential direction, and multiple blocks are set corresponding to the slots. The other is to evenly distribute multiple blocks along the spiral line, and the spiral line spirally extends around the central axis of the output shaft of the motor. The second one is generally selected.

[0042] The implementation principle of a low-loss centrifugal fan in the embodiment of the present application is as follows: when the centrifugal fan speed is low, the motor dissipates heat through passive heat dissipation. When the centrifugal fan speed is high, the motor passive heat dissipation is not enough to keep the motor working for a long time. Therefore, the centrifugal force is used to make the card block snap into the card slot to drive the heat dissipation wind wheel to actively dissipate heat for the motor. At this time, the spring is stretched, and when the centrifugal fan rotates, it will retract into the receiving slot.

[0043] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0044] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

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

[0046] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present 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 an output shaft of the motor is fixedly connected to a blade shaft of the centrifugal fan, characterized in that: It also includes a heat dissipation fan wheel which is colinear with the rotation axis of the output shaft of the motor. A gap is set between the heat dissipation fan wheel and the output shaft of the motor. A support frame for supporting the heat dissipation fan wheel is installed on the bracket. The output shaft of the motor has a telescopic clamp, and the heat dissipation fan wheel has a corresponding slot. When the output shaft speed of the motor reaches a set value, the telescopic clamp is clamped into the slot under the influence of centrifugal force, driving the heat dissipation fan wheel to rotate together.

2. A low-loss centrifugal fan according to claim 1, characterized in that: The slot extends from the tangent direction, and the depth of the slot gradually increases.

3. A low-loss centrifugal fan according to claim 2, characterized in that: A magnet is arranged at the bottom of the slot, and the telescopic card is magnetically attracted to the magnet. The magnet can suck the telescopic card into the slot when the radial gap between the telescopic card and the heat dissipation wind wheel is smaller than a set value.

4. A low-loss centrifugal fan according to claim 1, characterized in that: Sleeves are formed on both sides of the center of the heat dissipation wind wheel, a bearing is arranged inside the support frame, and the outer wall of the sleeve is interference fit with the inner ring of the bearing. One support frame is arranged on each side of the heat dissipation wind wheel.

5. A low-loss centrifugal fan according to claim 1, characterized in that: The telescopic clamp comprises a clamping block and a spring. A receiving groove for receiving the clamping block is provided in the output shaft of the centrifugal fan. The spring connects the receiving groove and the clamping block.

6. A low-loss centrifugal fan according to claim 5, characterized in that: A reinforcing ring is interference-fitted on the clamping block. After the clamping block is clamped into the clamping slot, the reinforcing ring is located at the opening of the receiving slot, and part of the reinforcing ring is located in the receiving slot and part of it extends out of the receiving slot.

7. A low-loss centrifugal fan according to claim 5, characterized in that: The card blocks are evenly distributed in a circumferential direction, and the card slots are arranged in a plurality corresponding to the card blocks.

8. A low-loss centrifugal fan according to claim 5, characterized in that: A plurality of the clamping blocks are evenly distributed along the spiral line, and the spiral line spirally extends around the central axis of the output shaft of the motor.

9. A low-loss centrifugal fan according to claim 3, characterized in that: The magnet is a permanent magnet.

10. A low-loss centrifugal fan according to claim 1, characterized in that: The blade shaft of the centrifugal fan adopts a deep groove ball bearing to match the frame.

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