Flow regulating device and control method, fan, and gas water heater

Abstract

The present invention relates to the field of fans, and specifically discloses a flow regulating device and a control method, a fan, and a gas water heater. The gas water heater includes the fan, and the fan includes the flow regulating device. The control method of the flow regulating device is used to control the flow regulating device. The flow regulating device includes a shell, an elastic member, an adjusting part, a coil, and a permanent magnet. A channel is provided in the shell, and the adjusting part is provided in the channel. The adjusting part is provided at the free end of the elastic member and can move with the free end to change the size of the inlet of the channel. The permanent magnet is provided on the adjusting part. After the coil is energized, the permanent magnet can be controlled to move closer to or away from the coil to change the size of the inlet. By providing the adjusting part at the free end of the elastic member to change the size of the inlet of the channel, the flow regulation of the channel is achieved. By providing the coil and the permanent magnet to adjust the flow, the precise control of the flow is achieved. By adjusting the flow in these two ways, the reliability of the flow regulation is improved.

Description

Technical Field

[0001] The present invention relates to the field of fans, and in particular to a flow regulating device and a control method, a fan, and a gas water heater. Background Art

[0002] The air volume of the fan inlet of the existing gas water heater is not adjustable, and gas water heaters of different powers need to be matched with fans of different models to meet the blowing requirements, and the fans have poor versatility. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defect that the air intake volume of the fan of the gas water heater in the prior art cannot be adjusted, and to provide a flow regulating device and control method, a fan, and a gas water heater.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] A flow regulating device, comprising:

[0006] a housing, wherein a passage is provided in the housing;

[0007] An elastic member, one end of which is a free end and the other end of which is a fixed end;

[0008] an adjusting portion, the adjusting portion being arranged in the channel, the adjusting portion being arranged at the free end and being able to move with the free end to change the size of the inlet of the channel;

[0009] The coil is provided with a permanent magnet on the adjustment part, the coil is arranged corresponding to the permanent magnet, and the position of the coil relative to the channel is fixed. After the coil is energized, the permanent magnet can be controlled to move closer to or away from the coil to change the size of the inlet.

[0010] In the present technical solution, the fixed end position of the elastic member is fixed relative to the channel, and the free end position can be changed relative to the channel; the adjusting part is arranged in the channel, and the adjusting part is arranged at the free end of the elastic member. Under the action of the fluid pressure difference, the two ends of the adjusting part will drive the free end of the elastic member to move together. After the elastic member is stretched and contracted, the pressure difference at the two ends of the adjusting part and the elastic force of the elastic member are balanced. The movement of the adjusting part can change the size of the channel inlet to achieve flow regulation. When the pressure difference at the two ends of the adjusting part is large, the opening of the inlet is large to increase the flow. When the pressure difference at the two ends of the adjusting part is small, the opening of the inlet is small to reduce the flow. A permanent magnet is arranged on the adjusting part, and the permanent magnet is controlled to move closer to or away from the coil by the size and direction of the current in the coil, that is, the permanent magnet is controlled to drive the adjusting part to move in the channel, so as to change the size of the inlet, adjust the flow, and realize precise control of the flow.

[0011] Preferably, the inlet is arranged on the circumferential surface of the shell, and the elastic member is arranged in the channel and can be extended and retracted along the axial direction of the channel.

[0012] In the technical solution, the elastic member is arranged in the channel, so that the flow regulating device has a compact structure and is convenient for connecting the elastic member and the regulating part. The inlet is arranged on the peripheral surface of the channel, and the elastic member can be extended and retracted along the axial direction of the channel, that is, the regulating part can drive the free end of the elastic member to move along the axial direction of the channel under the action of the fluid pressure difference, or the permanent magnet under the control of the coil, so as to change the size of the channel inlet to achieve flow regulation. The elastic member can be extended and retracted along the axial direction of the channel, so that the flow regulating device has a simple structure.

[0013] Preferably, there are multiple inlets, and the multiple inlets are located in the same cross section of the channel and are evenly distributed along the circumference of the channel.

[0014] In the technical solution, the inlets are distributed along the circumference of the channel, which facilitates the elastic member to extend and retract along the axial direction of the channel to drive the adjustment part to move and change the size of the inlet, making the structure simple. Multiple inlets are located at the same axial position of the channel, making the structure compact. Multiple inlets are evenly distributed along the circumference of the channel, which facilitates the fluid to enter the channel.

[0015] Preferably, the flow regulating device also includes a sensor and a control board, the sensor and the coil are electrically connected to the control board, the sensor is used to detect the position of the permanent magnet, and the control board is used to receive the detection data of the sensor and control the current size and direction of the coil to adjust the size of the inlet.

[0016] In the present technical solution, a permanent magnet is arranged on the regulating part, and a sensor detects the position of the permanent magnet, that is, the position information of the regulating part can be obtained; the energization of the coil is controlled according to the position information of the permanent magnet to adjust the position of the permanent magnet, that is, to adjust the position of the regulating part, so as to adjust the size of the inlet to achieve flow regulation, thereby realizing closed-loop control of flow regulation, and controlling the current in the coil according to the relative position information of the regulating part and the inlet, thereby controlling the movement of the permanent magnet on the regulating part to adjust the position of the regulating part and realize precise control of the flow.

[0017] Preferably, the sensor is a Hall sensor, and there are multiple Hall sensors, which are coded and evenly arranged along the expansion and contraction direction of the elastic member;

[0018] When the permanent magnet approaches any of the Hall sensors, the Hall sensor sends a signal to the control board.

[0019] In this technical solution, the position of the permanent magnet is detected by a Hall sensor, which is simple, reliable and easy to implement. One Hall sensor can detect one specific position, and multiple Hall sensors can detect multiple specific positions. Multiple Hall sensors are encoded so that the control board can recognize the sensor signal to control the current in the coil. Multiple Hall sensors are evenly arranged along the expansion and contraction direction of the elastic member to simplify the control of the coil current.

[0020] Preferably, the positions of the first and last Hall sensors correspond to the maximum compression position and the maximum tension position of the elastic member respectively.

[0021] In this technical solution, the two Hall sensors at the head and tail, one corresponds to the maximum compression position of the elastic member, and the other corresponds to the maximum stretching position of the elastic member, that is, multiple sensors just cover the extension and contraction range of the elastic member and can just detect the extreme position of the permanent magnet, making the sensor arrangement compact.

[0022] Preferably, the coil and the permanent magnet are arranged along the axial direction of the channel, and the coil is arranged on one side of the inlet, and the elastic member is arranged on the other side of the inlet.

[0023] In the present technical solution, the adjusting part is arranged at the free end of the elastic part, and the permanent magnet is arranged on the adjusting part, that is, the permanent magnet is arranged at the free end of the elastic part, and the permanent magnet, the adjusting part and the elastic part are all located on the other side of the inlet, so that the permanent magnet, the adjusting part and the elastic part can move together to adjust the size of the inlet.

[0024] A control method for a flow regulating device, which utilizes the flow regulating device in any of the above technical solutions, and the control method comprises the steps of:

[0025] The sensor detects the position of the permanent magnet and sends the detection data to the control board, and the control board calculates the real-time value of the inlet size of the channel based on the detection data of the sensor;

[0026] The control board compares the real-time value of the channel inlet with the preset value of the channel inlet size. If the real-time value is greater than the preset value, the control board passes a forward current through the coil to cause the coil to generate a magnetic force that attracts the permanent magnet; if the real-time value is less than the preset value, the control board passes a reverse current through the coil to cause the coil to generate a magnetic force that repels the permanent magnet.

[0027] In the present technical solution, under normal circumstances, different positions of the regulating part correspond to different preset values ​​of the inlet size. The position of the permanent magnet is detected by the sensor, and the information of the inlet size is obtained according to the position information of the permanent magnet. If the position of the permanent magnet, that is, the position of the regulating part, is the same as the preset value of the inlet size at this position, it means that the position of the regulating part matches the size of the inlet; if the position of the permanent magnet is different from the preset value of the inlet size at this position, it means that the position of the regulating part does not match the size of the inlet. By energizing the coil to make the permanent magnet drive the regulating part to move, the position of the permanent magnet matches the preset value of the inlet size. When the sensor is a Hall sensor, when the permanent magnet approaches any Hall sensor, the Hall sensor will send a signal to the control board, and the control board will calculate the position of the permanent magnet according to the coding information of the Hall sensor, and then obtain the preset value of the inlet size.

[0028] A fan comprises a motor, a volute, blades and a flow regulating device according to any of the above-mentioned technical solutions, wherein the blades are arranged in the volute, the motor is dynamically connected to the blades, the flow regulating device is connected to the volute, and the flow channel of the volute is connected to the outlet of the channel.

[0029] A gas water heater comprises the above-mentioned fan.

[0030] The positive and progressive effects of the present invention are:

[0031] By setting the regulating part and the elastic part, the regulating part is set in the channel, and the regulating part is set at the free end of the elastic part, so that the regulating part can move under the action of the fluid pressure difference to change the inlet size of the channel, thereby realizing the flow regulation of the channel. By setting the coil and the permanent magnet, and setting the permanent magnet on the regulating part, the permanent magnet can be controlled to drive the regulating part to move to adjust the flow by energizing the coil, thereby realizing the precise control of the flow. The flow is automatically adjusted by the fluid pressure difference, and the flow is actively adjusted by energizing the coil. The flow is adjusted by these two methods, thereby improving the reliability of the flow regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the overall structure of a fan provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the overall structure of a fan provided by an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of the internal structure of a fan provided by an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the structure of a flow regulating device provided in one embodiment of the present invention;

[0036] Figure 5A cross-sectional view of an adjustment portion provided by an embodiment of the present invention;

[0037] Figure 6 A cross-sectional view of a partial structure of a flow regulating device provided by an embodiment of the present invention;

[0038] Figure 7 A cross-sectional view of a partial structure of a flow regulating device provided by an embodiment of the present invention;

[0039] Figure 8 A cross-sectional view of a partial structure of a flow regulating device provided in one embodiment of the present invention.

[0040] Description of reference numerals:

[0041] Flow regulating device 1;

[0042] Shell 10, channel 11, inlet 12, outlet 13, end face flange 14;

[0043] Elastic member 20, free end 211, fixed end 22;

[0044] Adjustment unit 30;

[0045] Coil 40, permanent magnet 50;

[0046] Sensor 60;

[0047] Fan 100 , motor 2 , blades 3 , volute 4 , flow channel 5 , air outlet 6 . DETAILED DESCRIPTION

[0048] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0049] Figure 1-Figure 8 A schematic structural diagram of a fan 100 provided in one embodiment of the present invention.

[0050] like Figure 1-Figure 3 As shown, the fan 100 includes a flow regulating device 1, a motor 2, a blade 3 and a volute 4, wherein the blade 3 is arranged in the volute 4, and the flow regulating device 1 and the motor 2 are arranged on the volute 4; the motor 2 is used to drive the blade 3 to rotate so as to suck wind into the air inlet of the volute 4, and then flow through the flow channel 5 of the volute 4 to the air outlet 6 of the volute 4 to flow out; the outlet 13 of the flow regulating device 1 is connected with the flow channel 5 of the volute 4, specifically connected with the air inlet in the middle of the volute 4, and the air volume entering the air inlet of the volute 4 is adjusted by the flow regulating device 1.

[0051] like Figure 4-Figure 8As shown, the flow regulating device 1 includes a housing 10, an elastic member 20, a regulating portion 30, a coil 40, a permanent magnet 50, a sensor 60, and a control board. A channel 11 is formed in the housing 10, and the channel 11 connects an inlet 12 and an outlet 13 on the housing 10, that is, the inlet 12 and the outlet 13 of the channel 11, and the outlet 13 of the channel 11 connects to the air inlet in the middle of the volute 4. One end of the elastic member 20 is a free end 211, and the other end is a fixed end 22. The free end 211 corresponds to the inlet 12 of the channel 11, and the fixed end 22 corresponds to the outlet 13 of the channel 11 and is fixed on the end face flange 14 of the shell 10; the adjusting portion 30 is arranged at the free end 211 of the elastic member 20. When the motor 2 drives the blade 3 to rotate, in the extension direction of the channel 11, the two ends of the adjusting portion 30 are affected by the fluid pressure difference, which will drive the elastic member 20 to move in the channel 11, thereby changing the size of the inlet 12 of the channel 11 to adjust the air volume entering the channel 11; the permanent magnet 50 is arranged on the adjusting portion 30, and the coil 40 is arranged on the shell 10. By energizing the coil 40 so that the permanent magnet 50 is subjected to the magnetic force to drive the adjusting portion 30 to move in the channel 11, thereby changing the size of the inlet 12 of the channel 11 to achieve flow regulation. When the fan 100 is working, the motor 2 drives the blades 3 to rotate, a negative pressure area is formed inside the fan 100, and air enters the fan 100 from the inlet 12 of the channel 11. The adjustment part 30 slides toward the outlet 13 of the channel 11 due to the pressure difference on both sides. The more the sliding displacement, the larger the inlet 12, the larger the air intake area available for air intake, and the greater the air volume. It can be achieved that the air intake area changes with the speed of the fan 100. The higher the speed of the fan 100, the larger the air intake area.

[0052] In this embodiment, the coil 40 and the sensor 60 are both electrically connected to the control board. The sensor 60 detects the position of the permanent magnet 50 and sends the position information of the permanent magnet 50 to the control board. The control board then obtains the position information of the regulating part 30 and the size of the inlet 12 of the channel 11 based on the position information of the permanent magnet 50, and then controls the current in the coil 40 to control the movement of the permanent magnet 50 to achieve flow regulation.

[0053] Specifically, the sensor 60 is a Hall sensor 60, such as Figure 1 , Figure 2 , Figure 4 As shown, there are sixteen Hall sensors 60, eight on each side of the shell 10, each sensor 60 has a code, and the Hall sensors 60 on both sides are evenly distributed along the extension direction of the channel 11, that is, the expansion and contraction direction of the elastic member 20, and in the axial direction of the channel 11, the two sensors 60 closest to the outlet 13 correspond to the maximum compression position of the elastic member 20, and the two sensors 60 farthest from the outlet 13 correspond to the initial position of the elastic member 20 after pre-tightening, that is, the position when the inlet 12 is just closed.

[0054] The preset values ​​of the size of the inlet 12 corresponding to the adjustment part 30 being located at different positions are different. When the permanent magnet 50 is close to any sensor 60, the sensor 60 detects the data and sends the detected data to the control board. The control board determines the position of the permanent magnet 50 based on the received data and the coding information of the sensor 60, and then calculates the real-time value of the position of the adjustment part 30 and the size of the inlet 12. If the size of the inlet 12 does not correspond to the position of the permanent magnet 50 and the adjustment part 30, the control board sends an electrical signal to control the size and direction of the current in the coil 40. The permanent magnet 50 is subjected to the magnetic force under the action of the magnetic field generated by the coil 40 to drive the adjustment part 30 to move, so that the size of the inlet 12 matches the position of the permanent magnet 50 and the adjustment part 30. Specifically, if the real-time value is greater than the preset value, the control board passes a forward current through the coil 40 so that the coil 40 generates a magnetic force that attracts the permanent magnet 50, so that the permanent magnet 50 drives the adjustment part 30 to move toward the coil 40, thereby reducing the size of the inlet 12; if the real-time value is less than the preset value, the control board passes a reverse current through the coil 40 so that the coil 40 generates a magnetic force that repels the permanent magnet 50, so that the permanent magnet 50 drives the adjustment part 30 to move away from the coil 40, thereby increasing the size of the inlet 12.

[0055] In other embodiments, the corresponding relationship between the sensor 60 and the position of the extension limit point of the elastic member 20 may also be different from that in this embodiment. The positions of the first and last sensors 60 may correspond to the maximum compression position and the maximum extension position of the elastic member 20 respectively.

[0056] like Figure 1 , Figure 2 , Figure 4 , Figure 8 As shown, there are sixteen Hall sensors 60, eight on each side of the housing 10. By detecting the position of the permanent magnet 50 through two rows of sensors 60, it is possible to determine whether the position of the regulating part 30 is skewed based on the detection data of the sensor 60, so as to facilitate the inspection or adjustment of the flow regulating device 1; there are four permanent magnets 50, which are evenly arranged in the circumferential direction of the coil 40, so that the permanent magnets 50 are subjected to balanced magnetic force under the action of the coil 40. In other embodiments, the number of sensors 60 and permanent magnets 50 may be different from that of this embodiment, as long as the position of the permanent magnet 50 can be detected to control the movement of the regulating part 30 for flow regulation.

[0057] like Figure 4 and Figure 8As shown, in the circumferential direction of the housing 10, the positions of the Hall sensor 60 and the permanent magnet 50 correspond, both corresponding to the middle area of ​​the two inlets 12, so that the distance between the Hall sensor 60 and the permanent magnet 50 is small, so as to facilitate detection. And in the circumferential direction of the housing 10, the Hall sensor 60 corresponds to the middle area of ​​the two inlets 12, so as to arrange the Hall sensor 60 and the initial state of the permanent magnet 50 in the axial direction of the housing 10, that is, the cross-sectional direction, so as to facilitate detection of the initial state. In the circumferential direction of the housing 10, the permanent magnet 50 corresponds to the middle area of ​​the two inlets 12 to reduce the influence of the permanent magnet 50 on the fluid flow at the inlet 12. The coil 40 and the sensor 60 are arranged outside the channel 11 to prevent the fluid from affecting the operation of the coil 40 and the sensor 60, and at the same time facilitate debugging, maintenance and replacement.

[0058] In other embodiments, the type of sensor 60 may be different from that of the present embodiment. Other sensors 60 such as laser sensors 60 may be used to detect the position of the permanent magnet 50 to obtain the size of the inlet 12, or to detect the position of the regulating part 30 to obtain the size of the inlet 12, or to use a pressure sensor 60 to detect the elastic force on the elastic member 20 to obtain the position of the regulating part 30, and then obtain the size of the inlet 12, or to use a flow meter to detect the size of the flow of the inlet 12, etc., to obtain the size of the inlet 12 directly or indirectly, so as to control the movement of the regulating part 30 according to the fluid flow conditions. In other embodiments, the position and quantity of the sensor 60 and the permanent magnet 50 may be different from those of the present embodiment, as long as the sensor 60 can detect the position of the permanent magnet 50. In other embodiments, the position of the sensor 60 and the coil 40 may be different from that of the present embodiment, as long as the sensor 60 can detect the position of the permanent magnet 50.

[0059] In this embodiment, the housing 10 is provided with an outer convex end edge to facilitate fixing the fixed end 22 of the regulating part 30, so that the flow regulating device 1 has a compact structure; the elastic member 20 is arranged in the channel 11, so that the structure is compact and convenient to connect with the free end 211 of the regulating part 30; the elastic member 20 is specifically a spring that can be axially retracted. In other embodiments, the elastic member 20 can also be a spring that can be radially retracted, and the radial retraction of the elastic member 20 drives the regulating part 30 to rotate to change the size of the inlet 12. Accordingly, the channel 11 is arranged along the radial direction of the elastic member 20, so that the two ends of the regulating part 30 can be affected by the pressure difference of the fluid. In other embodiments, the elastic member 20 can also be other elements with retractable properties.

[0060] In this embodiment, the inlet 12 is arranged on the circumferential surface of the housing 10, and the elastic member 20 is arranged in the channel 11 and can be retracted and contracted along the axial direction of the channel 11, so that the inlet 12 is in a closed state when the flow regulating device 1 is not working through the pre-tightening setting of the elastic member 20; at the same time, the inlet 12 is arranged on the circumferential surface of the housing 10, and in the axial direction of the channel 11, the coil 40 is arranged on one side of the inlet 12, and the elastic member 20 is arranged on the other side of the housing 10, so that the coil 40 is arranged at the end of the housing 10, so that the structure is compact, and it is convenient for the coil 40 to control the permanent magnet 50 to drive the adjustment part 30 and the elastic member 20 to move together to adjust the size of the inlet 12. In other embodiments, the inlet 12 can also be arranged on the end surface of the housing 10. In this embodiment, multiple inlets 12 are located at the same cross-sectional position of the channel 11, that is, the same axial position of the channel 11, so that the structure is compact; multiple inlets 12 are evenly distributed along the circumference of the channel 11, so that the fluid flows into the channel 11.

[0061] The fan 100 of this embodiment is applied to a gas water heater to obtain a gas water heater with adjustable air volume. As for how to apply the fan 100 to a gas water heater, the prior art is mature, and please refer to the prior art for details.

[0062] When the fan 100 is applied to a gas water heater, the matching relationship between the position of the regulating part 30 in the flow regulating device 1 and the preset value of the size of the inlet 12 is set according to the combustion demand of the gas water heater. Under a certain power of the gas water heater, the gas combustion condition test is carried out at different speeds of the motor 2, and a preferred value is selected by considering the combustion completeness, vibration of the motor 2, wind resistance performance index, etc., and the size of the inlet 12 corresponding to the preferred value is matched with the position of the regulating part 30 to obtain a set of preset values ​​of the size of the inlet 12 corresponding to the position of the regulating part 30; the power of the gas water heater is changed, and tests are carried out to obtain the preset values ​​of the size of the inlet 12 corresponding to other positions of the regulating part 30.

[0063] In other embodiments, the matching relationship between the position of the regulating part 30 and the preset value of the size of the inlet 12 can also be directly obtained based on the matching test of the motor 2 and the air intake volume. The specific method can be: testing the position of the regulating part 30 and the size of the inlet 12 corresponding to the motor 2 at a certain speed to obtain a set of preset values ​​of the size of the inlet 12 corresponding to the position of the regulating part 30; changing the speed of the motor 2, and conducting tests to obtain the preset values ​​of the size of the inlet 12 corresponding to other positions of the regulating part 30.

[0064] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A flow regulating device, characterized in that: The flow regulating device comprises: A shell, wherein a channel is disposed in the shell, and an inlet of the channel is disposed on a peripheral surface of the shell; An elastic member, one end of which is a free end, the other end of which is a fixed end, and the elastic member is arranged in the channel and can be extended and retracted along the axial direction of the channel; an adjusting portion, the adjusting portion being arranged in the channel, the adjusting portion being arranged at the free end and being able to move with the free end to change the size of the inlet; A coil, a permanent magnet is provided on the adjusting part, the coil is arranged corresponding to the permanent magnet, and the position of the coil relative to the channel is fixed. When the coil is energized, the permanent magnet can be controlled to move closer to or away from the coil to change the size of the inlet; A sensor and a control board, wherein the sensor and the coil are both electrically connected to the control board, the sensor is used to detect the position of the permanent magnet, and the control board is used to receive the detection data of the sensor and control the current size and direction of the coil to adjust the size of the inlet.

2. The flow regulating device according to claim 1, characterized in that: The number of the inlets is multiple, and the multiple inlets are located in the same cross section of the channel and are evenly distributed along the circumference of the channel.

3. The flow regulating device according to claim 1, characterized in that: The sensor is a Hall sensor, and there are multiple Hall sensors, which are encoded and evenly arranged along the expansion and contraction direction of the elastic member; When the permanent magnet approaches any of the Hall sensors, the Hall sensor sends a signal to the control board.

4. The flow regulating device according to claim 3, characterized in that: The positions of the first and last Hall sensors correspond to the maximum compression position and the maximum tension position of the elastic member respectively.

5. The flow regulating device according to claim 1, characterized in that: The coil and the permanent magnet are arranged along the axial direction of the channel, and the coil is disposed on one side of the inlet, and the elastic member is disposed on the other side of the inlet.

6. A control method for a flow regulating device, characterized in that: Using the flow regulating device as described in any one of claims 1 to 5, the control method comprises the steps of: The sensor detects the position of the permanent magnet and sends the detection data to the control board, and the control board calculates the real-time value of the inlet size of the channel based on the detection data of the sensor; The control board compares the real-time value of the channel inlet with the preset value of the channel inlet size. If the real-time value is greater than the preset value, the control board passes a forward current through the coil to cause the coil to generate a magnetic force that attracts the permanent magnet; if the real-time value is less than the preset value, the control board passes a reverse current through the coil to cause the coil to generate a magnetic force that repels the permanent magnet.

7. A fan, characterized in that: It includes a motor, a volute, blades and a flow regulating device as described in any one of claims 1 to 5, wherein the blades are arranged in the volute, the motor is dynamically connected to the blades, the flow regulating device is connected to the volute, and the flow channel of the volute is connected to the outlet of the channel.

8. A gas water heater, characterized in that: It comprises the fan as claimed in claim 7.

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