Flow sensor and water heater

Abstract

The utility model relates to a flow sensor and a water heater. The flow sensor comprises a rotor and a sensing part, the rotor is used for being arranged in fluid and driven by the fluid to rotate, the rotor comprises more than two blades arranged at intervals in the circumferential direction, the two ends, in the axial direction of the rotor, of each blade are correspondingly a liquid inlet end and a liquid outlet end, the end face of the liquid inlet end of each blade is arranged to be a flow guide face, and each flow guide face comprises an inclined face. The inclined surface is obliquely arranged relative to the axial direction of the rotor; the induction piece is located on the radial side of the rotor and used for conducting mutual induction with at least one part of the blades so as to detect rotation of the rotor. The liquid inlet ends of the blades are provided with the flow guide faces including the inclined faces, fluid can drive the rotor to rotate more easily, and therefore the measuring sensitivity and accuracy of the flow sensor are improved.

Description

Technical Field

[0001] This utility model relates to the field of flow sensor technology, and in particular to a flow sensor and a water heater. Background Technology

[0002] Water flow sensors are commonly used in daily life, and are frequently found in household appliances such as gas water heaters. They typically consist of a rotor and a sensing element. The rotor is placed in the fluid being measured and rotates under the influence of the fluid. The sensing element detects the rotor's rotation to identify the flow rate of the fluid. In developing this invention, the inventors discovered that this type of flow sensor is prone to low sensitivity and inaccurate detection when the flow rate of the fluid being measured is small. Utility Model Content

[0003] One objective of this invention is to address the shortcomings of existing flow sensors, such as low detection sensitivity and inaccurate measurement, and to provide a flow sensor.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] The first aspect of this application proposes a flow sensor, comprising:

[0006] A rotor is used to be placed in a fluid and rotated under the drive of the fluid. The rotor includes two or more blades arranged circumferentially, and the two ends of each blade along the axial direction of the rotor are respectively a liquid inlet end and a liquid outlet end. The end face of the liquid inlet end of the blade is configured as a flow guide surface, and the flow guide surface includes an inclined surface, and the inclined surface is inclined relative to the axial direction of the rotor.

[0007] A sensing element, located on the radial side of the rotor, is used to sense at least a portion of the blades to detect the rotation of the rotor.

[0008] According to some technical solutions of this application, the inclination angle of the inclined surface relative to the rotor axis ranges from 100° to 150°.

[0009] According to some technical solutions of this application, the guide surface is generally the inclined surface; the blade forms a first side surface and a second side surface at both ends along the wall thickness direction, the inclined surface extends obliquely from one end of the first side surface to one end of the second side surface, and the inclined surface is oblique relative to the first side surface and the second side surface respectively, the connection between the inclined surface and the first side surface is chamfered or rounded, and the connection between the inclined surface and the second side surface is chamfered or rounded.

[0010] According to some technical solutions of this application, in two or more blades of the rotor, the inclined surfaces of the liquid inlet ends of each blade have the same inclination direction.

[0011] According to some technical solutions of this application, in two or more blades of the rotor, the inclined surfaces of the liquid inlet ends of each blade are distributed symmetrically along the circumference of the rotor.

[0012] According to some technical solutions of this application, the end face of the liquid outlet end of the blade is also configured as the flow guiding surface.

[0013] According to some technical solutions of this application, the rotor further includes a central part, the blades are distributed on the outer periphery of the central part, and each blade is connected to the central part; the central part has planar shaft end faces at both axial ends, and the inclined surfaces are inclined relative to the shaft end faces.

[0014] According to some technical solutions of this application, the center of the central part is provided with an axially penetrating through hole, and the flow sensor also includes a shaft part, which is inserted into the through hole and can rotate within the through hole. The shaft part is provided with two axially spaced stop parts, and the central part is axially confined between the two stop parts; the diameter of the stop part is less than or equal to the diameter of the shaft end face.

[0015] According to some technical solutions of this application, the two ends of each blade along the rotor axis do not extend beyond the two ends of the central part along the axial direction.

[0016] According to some technical solutions of this application, at least the blades of the rotor are magnetic cores, and the sensing element includes an inductor coil; or at least the blades of the rotor are magnets, and the sensing element includes a Hall element.

[0017] The second aspect of this application provides a water heater, including a water inlet pipe and a flow sensor as described in any of the above technical solutions. The flow sensor is connected to the water inlet pipe, and the water inlet pipe is used to deliver fluid to the flow sensor to drive the rotor to rotate.

[0018] As can be seen from the above technical solution, this utility model has at least the following advantages and positive effects:

[0019] In this application, the flow sensor includes a rotor and a sensing element. The rotor is placed in the fluid whose flow rate is to be measured and rotates under the drive of the fluid. The sensing element detects the rotation of the rotor by mutual inductance with at least a portion of the rotor, thereby identifying the flow rate of the fluid to be measured based on the rotation of the rotor. The rotor is configured to include two or more blades arranged circumferentially. A guide surface is provided at the inlet end of the blades, and this guide surface includes an inclined surface that is tilted relative to the axial direction of the rotor. This reduces the flow resistance when the fluid contacts the inlet end of the blades, allowing the fluid's power to be more efficiently converted into the rotational motion of the rotor. This makes the rotor's rotational speed more accurately reflect the fluid flow rate. Consequently, the flow rate identified by the sensing element based on the rotor's rotational speed is more realistic and accurate, improving the flow measurement accuracy of the flow sensor. By reducing the flow resistance at the inlet end of the blades, the rotor can also be driven by smaller flow rates of fluid, avoiding the problem of the rotor being unable to be driven smoothly by smaller flow rates due to high blade flow resistance. This further lowers the lower limit of the flow detection range of the flow sensor, improving the measurement sensitivity of the flow sensor. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the flow sensor according to an embodiment.

[0021] Figure 2 yes Figure 1 A cross-sectional schematic diagram of the structure shown.

[0022] Figure 3 yes Figure 2 The diagram shows the structure of the rotor.

[0023] Figure 4 yes Figure 3 The diagram shows a side view of the rotor.

[0024] The annotations in the attached figures are explained as follows:

[0025] 100 - Housing; 110 - Inlet; 120 - Outlet; 130 - Bracket; 131 - Shaft hole;

[0026] 200 - Rotor; 210 - Blade; 211 - First inclined surface; 212 - Second inclined surface; 213 - First side surface; 214 - Second side surface; 220 - Shaft body; 230 - Center part; 231 - Stop part; 232 - Stop part;

[0027] 300 - Sensor;

[0028] 400 - Flow guide; 410 - Center body; 411 - Rotary hole; 420 - Flow guide vane; 430 - Ring body. Detailed Implementation

[0029] Typical embodiments embodying the features and advantages of this utility model will be described in detail in the following description. It should be understood that this utility model can have various variations in different embodiments, all of which do not depart from the scope of this utility model, and the descriptions and illustrations therein are for illustrative purposes only and not intended to limit this utility model.

[0030] In the description of this application, it should be understood that, in the embodiments shown in the accompanying drawings, the indications of direction or positional relationships (such as up, down, left, right, front, and back) are merely for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the accompanying drawings. If the description of the positions of these elements changes, these directional indications also change accordingly.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] The flow sensor proposed in this application is illustrated using the example of detecting the flow rate of water. Those skilled in the art will readily understand that various modifications, additions, substitutions, deletions, or other changes can be made to the specific embodiments described below to apply the design of the flow sensor to the detection of other types of liquids or gases. These changes are still within the scope of the principle of the flow sensor proposed in this utility model.

[0033] Please see Figure 1 and Figure 2 As shown, the flow sensor according to an embodiment of the present invention includes a housing 100, a rotor 200, and a sensing element 300. The housing 100 is hollow and forms a fluid channel for fluid flow. The housing 100 is provided with an inlet 110 and an outlet 120 communicating with the fluid channel.

[0034] like Figure 2 As shown, for example, the housing 100 can be a cylindrical structure, and the interior of the housing 100 is hollow to allow fluid to flow. The two axial ends of the housing 100 are openings, which serve as inlet 110 for fluid entry and outlet 120 for fluid exit, respectively.

[0035] The rotor 200 is rotatably disposed within the fluid channel, and the axial direction of the rotor 200 is arranged along the flow direction of the fluid. The rotor 200 has two or more blades 210 arranged circumferentially spaced apart. The two ends of each blade 210 along the axial direction of the rotor 200 are respectively the inlet end and the outlet end. The inlet end of the blade 210 is relatively closer to the inlet 110 and relatively farther from the outlet 120, and the outlet end of the blade 210 is relatively closer to the outlet 120 and relatively farther from the inlet 110. The end face of the inlet end of the blade is configured as a guide surface, which includes a first inclined surface 211, and the first inclined surface 211 is inclined relative to the axial direction of the rotor 200.

[0036] The sensor 300 is located on the radial side of the rotor 200 and is used to sense at least a portion of the blade 210 to detect the rotation of the rotor 200.

[0037] See Figure 1 Preferably, the sensor 300 is disposed on the outside of the housing 100, and the sensor 300 is separated from the rotor 200 by the side wall of the housing 100. In this way, the sensor 300 will not come into contact with the fluid in the fluid channel, which can better achieve water vapor isolation and reduce the risk of product failure.

[0038] Optionally, the portion of the blade 210 that interacts with the sensing element 300 is a magnetic core. It is understood that the magnetic core is, for example, a soft magnetic material. The sensing element 300 is an inductor coil. Thus, when the rotor 200 rotates relative to the sensing element 300 under the drive of the fluid, the multiple blades 210 circumferentially around the rotor 200 dynamically and alternately approach and move away from the sensing element 300. It is understood that when the blades 210 are relatively close to the inductor coil, the inductor coil responds to the approach of the blades 210 by generating a relatively large inductance; when the blades 210 are relatively far from the inductor coil, the inductor coil responds to the distance from the blades 210 by generating a relatively small inductance or no inductance. Thus, through the dynamic alternation of approach and distance between the blades 210 and the inductor coil, an alternating change in inductance is induced in the inductor coil, and this change in inductance reflects the rotational speed of the rotor 200, thereby reflecting the flow rate of the fluid driving the rotor 200's rotation, achieving the purpose of flow detection.

[0039] Optionally, the portion of the blades 210 that interacts with the sensing element 300 is a magnet. It is understood that the magnetic core is, for example, a hard magnetic material. The sensing element includes a Hall element. Thus, when the rotor 200 rotates relative to the sensing element 300 under the drive of the fluid, the multiple blades 210 circumferentially around the rotor 200 dynamically and alternately approach and move away from the sensing element 300. Through the dynamic and alternating approach and movement of the multiple blades 210 towards and away from the sensing element 300, the Hall element can detect changes in the magnetic field of the magnet, thereby identifying the rotor's rotational speed and correspondingly identifying the fluid flow rate, achieving the purpose of flow detection.

[0040] It is understandable that, regardless of whether a magnetic core or a magnet is used, the blade 210 must possess a certain strength and magnetism. Based on this, in the embodiment, as... Figure 3 As shown, the blade 210 is configured with a certain thickness. However, as the thickness of the blade 210 increases, the inlet end of the blade 210 also has a corresponding thickness. When the fluid comes into axial contact with the blade 210, a large flow resistance will be formed at the inlet end of the blade 210. Thus, when the fluid flows towards the blade, some kinetic energy will be lost at the inlet end of the blade. This loss of kinetic energy will cause a deviation in the flow rate detection result, especially when the flow rate of the fluid to be measured is small, the deviation in the detection result will be particularly prominent.

[0041] In this embodiment, a guide surface including the first inclined surface 211 is provided at the liquid inlet end of the blade 210, thereby greatly reducing the problem of large flow resistance at the liquid inlet end caused by the thickness configuration of the blade 210.

[0042] Specifically, the inclined plane guides the fluid to the side of the blade 210, reducing the impact and jamming between the fluid and the blade 210, making the fluid flow smoother. This helps reduce fluid resistance loss and allows the fluid to drive the rotor 200 to rotate more efficiently. Thus, the flow resistance when the fluid contacts the inlet end of the blade 210 is smaller, and the fluid's power can be more efficiently converted into the rotational motion of the rotor 200. This allows the rotor speed of the rotor 200 to more accurately reflect the fluid flow rate. Correspondingly, the fluid flow rate identified by the sensor 300 through the rotor speed of the rotor 200 is more realistic and accurate, improving the flow measurement accuracy of the flow sensor, especially the detection accuracy under low flow detection conditions. Furthermore, by reducing the flow resistance at the inlet end of the blade, the rotor can also be driven by a smaller flow rate of fluid, avoiding the problem that the rotor cannot be driven smoothly by a smaller flow rate of fluid due to the large flow resistance of the blade. This allows the lower limit of the flow detection range of the flow sensor to be further reduced, improving the measurement sensitivity of the flow sensor. Therefore, even if the fluid velocity is not high and the flow rate is small, the fluid can drive the rotor 200 to rotate well, resulting in better flow detection sensitivity.

[0043] Optionally, the inclination angle of the first inclined surface 211 relative to the axial direction of the rotor 200 ranges from 100° to 150°. Combined with... Figure 4 It is understood that the inclination angle of the first inclined surface 211 relative to the axial direction of the rotor 200 is approximately A+90°. The first inclined surface 211 is configured at this angle to ensure the strength requirements of the liquid inlet end of the blade 210, while also allowing the fluid guided by the first inclined surface 211 to flow through the liquid inlet end with less flow resistance.

[0044] Optionally, the guide surface at the liquid inlet end of the blade 210 is entirely a first inclined surface 211; the blade 210 forms a first side surface 213 and a second side surface 214 at its two ends along the wall thickness direction. The first inclined surface 211 extends obliquely from one end of the first side surface 213 to one end of the second side surface 214, and the first inclined surface 211 is inclined relative to the first side surface 213 and the second side surface 214, respectively. The connection between the first inclined surface 211 and the first side surface 213 is chamfered or rounded, and the connection between the first inclined surface 211 and the second side surface 214 is also chamfered or rounded. In this way, the flow resistance at the liquid inlet end of the blade 210 is small, and the entire guide surface is constructed by the first inclined surface 211, resulting in a simpler structure, which is beneficial for product manufacturing and better ensures the product yield.

[0045] In the embodiments of this application, each blade 210 of the rotor 200 has a first inclined surface 211 at its liquid inlet end. However, this application is not limited to this. In other embodiments, some blades 210 of the rotor 200 may have a first inclined surface 211 at their liquid inlet ends, while the liquid inlet ends of the remaining blades 210 may not have a first inclined surface 211.

[0046] Optionally, in the two or more blades 210 of the rotor 200, the inclination direction of the first inclined surface 211 at the liquid inlet end of each blade 210 is consistent. In this way, the fluid obtains the same component velocity in the same direction on the first inclined surface 211 of each blade 210 (e.g., all are clockwise or all are counterclockwise), so that the component velocity obtained by the fluid guided by the first inclined surface 211 of different blades 210 in the circumferential direction is consistent, thereby enhancing the efficiency of the fluid driving the rotor 200 and further improving the detection accuracy.

[0047] Optionally, in the two or more blades 210 of the rotor 200, the first inclined surface of the liquid inlet end of each blade 210 is distributed symmetrically along the circumference of the rotor 200. In this way, the fluid driving force at the liquid inlet end of each blade 210 of the rotor 200 is approximately uniformly distributed in the circumference, resulting in smoother rotation of the rotor 200, less rotational resistance loss, and further improved detection accuracy.

[0048] Optionally, the end face of the liquid outlet of the blade 210 is also configured as a guide surface. Accordingly, combined with... Figure 3 and Figure 4 It can be understood that the guide surface at the liquid outlet end of the blade 210 includes a second inclined surface 212, and the second inclined surface 212 is inclined relative to the axial direction of the rotor 200.

[0049] By configuring the liquid outlet end of the blade 210 with a second inclined surface 212, the fluid leaving the blade 210 along the axial direction can be guided by the second inclined surface 212 to leave the blade 210 more quickly, making the fluid flow smoother. This helps to reduce fluid resistance loss and also reduces the rotational resistance of the blade 210, thereby improving the flow measurement accuracy and sensitivity of the flow sensor.

[0050] Optionally, the inclination angle of the second inclined surface 212 relative to the axial direction of the rotor 200 ranges from 100° to 150°. Figure 4 It is understood that the inclination angle of the second inclined surface 212 relative to the axial direction of the rotor 200 is approximately B+90°. The second inclined surface 212 is configured at this angle to ensure the strength requirements of the liquid inlet end of the blade 210, while also allowing the fluid guided by the second inclined surface 212 to flow through the liquid outlet end with less flow resistance.

[0051] Optionally, the guide surface at the liquid outlet end of the blade 210 is a second inclined surface 212; the blade 210 forms a first side surface 213 and a second side surface 214 at both ends along the wall thickness direction, the second inclined surface 212 extends obliquely from one end of the first side surface 213 to one end of the second side surface 214, and the second inclined surface 212 is inclined relative to the first side surface 213 and the second side surface 214 respectively, the connection between the second inclined surface 212 and the first side surface 213 is chamfered or rounded, and the connection between the second inclined surface 212 and the second side surface 214 is chamfered or rounded.

[0052] In the embodiments of this application, the liquid outlet end of each blade 210 of the rotor 200 is provided with a second inclined surface 212. However, this application is not limited to this. In other embodiments, the liquid outlet end of some blades 210 of the rotor 200 may be provided with a second inclined surface 212, while the liquid outlet end of the remaining blades 210 may not be provided with a second inclined surface 212.

[0053] Optionally, in the two or more blades 210 of the rotor 200, the second inclined surface 212 at the liquid outlet end of each blade 210 has the same inclination direction.

[0054] Optionally, in the two or more blades 210 of the rotor 200, the second inclined surface 212 of the liquid outlet end of each blade 210 is distributed symmetrically along the circumference of the rotor 200.

[0055] The following text, in conjunction with the accompanying drawings, will further elaborate on the scheme where the portion of blade 210 used for mutual induction with the inductor 300 serves as the magnetic core. Of course, the scheme where the portion of blade 210 used for mutual induction with the inductor 300 serves as the magnet, or other corresponding alternatives, can also be understood similarly in conjunction with the following text and the accompanying drawings, provided there is no conflict.

[0056] Optionally, such as Figure 3As shown, each blade 210 can be integrally configured as a magnetic core. Alternatively, in other embodiments, a portion of each blade 210 can be configured as a magnetic core. For example, each blade 210 can be configured as a composite structure combining plastic and a magnetic core. For instance, a plastic shell in the shape of the blade 210 can be provided, with the plastic shell hollow and the magnetic core serving as an internal interlayer, housed inside the plastic shell.

[0057] Further optional, such as Figure 3 As shown, the rotor 200 also includes a central portion 230, with blades 210 distributed on the outer periphery of the central portion 230, and each blade 210 connected to the central portion 230. Optionally, each blade 210 and the central portion 230 are made of magnetic core material and formed as a single unit.

[0058] The central portion 230 has an axially penetrating through-hole at its center. The flow sensor also includes a shaft portion 220, which passes through the through-hole and can rotate within it. The shaft portion 220 has two axially spaced stop portions 231 and 232, which axially limit the central portion 230 between the two stop portions 231 and 232. To achieve smooth and reliable limiting between the axial ends of the central portion 230 and the two stop portions 231 and 232, each axial end of the central portion 230 has a planar shaft end face. The first inclined surface 211 is inclined relative to the shaft end face of the central portion 230 to effectively perform its flow guiding function.

[0059] The shaft body 230 can be made of plastic or metal, etc.

[0060] like Figure 3 As shown, the diameter of the stop portion 231 and / or the stop portion 232 is less than or equal to the diameter of the shaft end face. This prevents the stop portion 231 and / or the stop portion 232 from creating additional flow resistance, thereby ensuring the detection accuracy of the flow sensor. Furthermore, by designing the diameter of the stop portion 231 and / or the stop portion 232 to be smaller than the diameter of the shaft end face, a gradually decreasing diameter step transition is formed between the stop portion 231 and / or the stop portion 232 and the shaft end face of the center portion 230. This allows the fluid to receive some guidance when it axially contacts the stop portion and the center portion 230, further reducing flow resistance.

[0061] like Figure 3 As shown, the two ends of each blade 210 along the axial direction of the rotor 200 do not extend beyond the two ends of the central portion 230. In this way, the central portion 230 can be used to form axial clearance protection for the blades 210, preventing damage to the first inclined surface 211 of the blades 210, thereby ensuring the guiding effect of the first inclined surface 211.

[0062] See Figure 4In one embodiment, the inlet and outlet ends of the blade 210 are respectively provided with a first inclined surface 211 and a second inclined surface 212, with the first inclined surface 211 and the second inclined surface 212 being parallel to each other. Specifically, the first inclined surface 211 may be inclined from the first side surface 213 toward the second side surface 214. The second inclined surface 212 may also be inclined from the first side surface 213 toward the second side surface 214.

[0063] Optionally, the first inclined plane 211 and the second inclined plane 212 have the same inclination angle. For example... Figure 4 As shown, in one embodiment, the tilt angle (A+90°) of the first inclined surface 211 relative to the axial direction of the rotor 200 and the tilt angle (B+90°) of the second inclined surface 212 relative to the axial direction of the rotor 200 can both be 120°.

[0064] In other embodiments, the inclination angle of the first inclined surface 211 and the second inclined surface 212 relative to the axial direction of the rotor 200 can be any angle within the range of 100° to 150° or 120° to 135°.

[0065] In this embodiment, the first inclined surface 211 and the second inclined surface 212 of the blade 210 are configured to have the same inclination method and inclination angle, which facilitates the modular manufacturing and assembly of the rotor 200 and avoids the need to distinguish between the first inclined surface 211 and the second inclined surface 212 when manufacturing and assembling the rotor 200, thereby simplifying the manufacturing and assembly process.

[0066] In the embodiments of this application, by reasonably designing the tilt angles of the first inclined surface 211 and the second inclined surface 212, it can be ensured that the inclined surface can better drive the rotor 200 to rotate under the action of fluid impact, while ensuring that the volume of the blade 210 is not reduced too much, thereby ensuring that the blade 210 has sufficient magnetism to ensure the sensing sensitivity of the sensor.

[0067] In one possible embodiment of this application, the inclination angle of the first inclined surface 211 relative to the axial direction of the rotor 200 is different from the inclination angle of the second inclined surface 212 relative to the axial direction of the rotor 200. For example, the inclination angle of the first inclined surface 211 relative to the axial direction of the rotor 200 may be 135°, while the inclination angle of the second inclined surface 212 relative to the axial direction of the rotor 200 may be 120°. Alternatively, the first inclined surface 211 and the second inclined surface 212 may be arranged symmetrically to each other.

[0068] In another possible embodiment of this application, the first inclined surface 211 may be generally formed as a V-shape, having two inclined surfaces facing the first side surface 213 and the second side surface 214 respectively.

[0069] In another possible embodiment of this application, the second inclined surface 212 may be generally formed as a V-shape, having two inclined surfaces facing the first side surface 213 and the second side surface 214 respectively.

[0070] Alternatively, in other embodiments, the liquid outlet end of the blade 210 may not be configured as an inclined surface.

[0071] It should be noted that in this application, each inclined surface can be a plane. And the plane does not specifically refer to the first inclined surface 211 and the second inclined surface 212 of the blade 210 as an absolute plane, but should be understood openly as the end face of the blade 210 of this application can be set as a plane or a curved surface with a certain curvature (such as a concave or convex surface) as required.

[0072] See Figure 1 and Figure 2 In one embodiment, the flow sensor further includes a guide member 400, which is fixed at the inlet 110 of the housing 100. The rotor 200 is rotatable relative to the guide member 400. The guide member 400 is used to guide fluid flow, such that the fluid guided by the guide member 400 can drive the rotor 200 to rotate relative to the guide member 400. By providing the guide member 400, the driving efficiency of the fluid on the rotor 200 can be improved, thereby improving the flow sensor's accuracy in detecting fluid flow rate.

[0073] Preferably, the fluid guided by the guide member 400 can vertically impact the inclined first slope 211. This allows the fluid to more smoothly drive the rotor 200 to rotate, that is, the guide member 400 can drive the rotor 200 to rotate more efficiently, improving the flow sensor's detection accuracy of fluid flow.

[0074] For example, such as Figure 2 As shown, the flow guide 400 may include a central body 410 and a plurality of flow guide blades 420 arranged circumferentially at intervals along the central body 410, as well as an annular body 430. One end of each flow guide blade 420 is connected to the central body 410, and the other end is connected to the annular body 430.

[0075] Each guide vane 420 can have a certain helical curvature along the axial direction, so that the fluid moving along the axial direction in the fluid channel carries a circumferential velocity component after passing through the guide vane 420. In this way, the fluid carrying the circumferential velocity component will better drive the rotor 200 to rotate when it flows through each vane 210.

[0076] Optionally, the guide vane 420 may also have a certain helical curvature in the circumferential direction, which can further improve the guiding effect on the fluid.

[0077] Optionally, the flow guide 400 can be configured as a one-piece injection-molded plastic component. This reduces the cost of the flow guide 400, further lowering product costs. Of course, in other embodiments, the flow guide 400 can also be made of materials other than plastic.

[0078] Optionally, the connection between the flow guide 400 and the housing 100 can be a snap-fit ​​type, such as a snap-fit ​​on the ring 430 of the flow guide 400 to snap into the housing 100, to further improve assembly convenience. Of course, in other embodiments, the flow guide 400 and the housing 100 can also be connected using screws or other connecting parts.

[0079] like Figure 2 As shown, the central body 410 of the flow guide 400 has a rotating hole 411 for one end of the shaft portion 220 to pass through. A bracket 130 may be provided at the outlet 120 of the housing 100, and the bracket 130 has a shaft hole 131 for the other end of the shaft portion 200 to pass through. The flow guide 400 and the bracket 130 are respectively used to rotatably support the axial ends of the rotor 200.

[0080] In this embodiment, one end of the shaft portion 220 of the rotor 200 extends into the rotating hole 411 and can rotate within the rotating hole 411. The other end of the shaft portion 220 of the rotor 200 passes through the shaft hole 131 on the bracket 130 and can rotate within the shaft hole 131. In this way, the rotor 200, the flow guide 400, and the bracket 130 are positioned and assembled using the housing 100 as a carrier, which facilitates the positioning between the rotor 200 and the flow guide 400 and avoids problems such as misinstallation or reverse installation of the rotor 200 and the flow guide 400.

[0081] Optionally, the bracket 130 and the housing 100 can be integrally molded, for example, the housing 100 and the bracket 130 can be integrally injection molded. In this way, the connection between the bracket 130 and the housing 100 is more reliable, so that the rotor 200 can be supported more reliably and stably, and the assembly steps of the housing 100 and the bracket 130 are saved, thus saving the assembly time of the product.

[0082] In one embodiment of this utility model, a water heater is also provided, which includes an inlet pipe and a flow sensor as described in any of the above embodiments, the flow sensor being connected to the inlet pipe. By connecting the flow sensor to the inlet pipe, the fluid from the inlet pipe can be driven to rotate by a rotor 200 to detect the water flow rate in the inlet pipe. For example, the water heater may include a water heater body connected to the inlet pipe. The inlet pipe is used to communicate with an external water source, and the water heater body can receive water from the external water source along the inlet pipe.

[0083] For example, the flow sensor is connected to the inlet pipe, allowing fluid entering the fluid channel from the inlet pipe to drive the rotor 200 to rotate via the guide member 400, thereby detecting the water flow rate in the inlet pipe. Since the flow sensor of this embodiment has the above-mentioned beneficial effects, the water heater of this application also has all of the above-mentioned beneficial effects, which will not be elaborated further here.

[0084] The above embodiments are merely illustrative examples of structures. The structures in each embodiment are not fixed combinations. In the absence of structural conflicts, the structures in multiple embodiments can be arbitrarily combined and used.

[0085] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A flow sensor, characterized in that, include: A rotor is used to be placed in a fluid and rotated under the drive of the fluid. The rotor includes two or more blades arranged circumferentially, and the two ends of each blade along the axial direction of the rotor are respectively a liquid inlet end and a liquid outlet end. The end face of the liquid inlet end of the blade is configured as a flow guide surface, and the flow guide surface includes an inclined surface, and the inclined surface is inclined relative to the axial direction of the rotor. A sensing element, located on the radial side of the rotor, is used to sense at least a portion of the blades to detect the rotation of the rotor.

2. The flow sensor according to claim 1, characterized in that, The inclination angle of the inclined plane relative to the rotor axis ranges from 100° to 150°.

3. The flow sensor according to claim 1, characterized in that, The guide surface is entirely composed of the inclined surface; The blade forms a first side surface and a second side surface at both ends along the wall thickness direction. The inclined surface extends obliquely from one end of the first side surface to one end of the second side surface, and the inclined surface is oblique relative to the first side surface and the second side surface respectively. The connection between the inclined surface and the first side surface is chamfered or rounded. The connection between the inclined surface and the second side surface is chamfered or rounded.

4. The flow sensor according to claim 1, characterized in that, In the rotor, the inclined surfaces of the liquid inlet ends of the two or more blades are in the same direction.

5. The flow sensor according to claim 4, characterized in that, In the two or more blades of the rotor, the inclined surfaces of the liquid inlet ends of each blade are distributed symmetrically around the circumference of the rotor.

6. The flow sensor according to any one of claims 1 to 5, characterized in that, The end face of the liquid outlet end of the blade is also configured as the flow guiding surface.

7. The flow sensor according to any one of claims 1 to 5, characterized in that, The rotor also includes a central portion, and the blades are distributed on the outer periphery of the central portion, with each blade connected to the central portion. The central part has planar shaft end faces at both axial ends, and the inclined surface is inclined relative to the shaft end face.

8. The flow sensor according to claim 7, characterized in that, The center of the central part is provided with an axially penetrating through hole. The flow sensor also includes a shaft part, which is inserted into the through hole and can rotate within the through hole. The shaft part is provided with two axially spaced stop parts, and the central part is axially confined between the two stop parts. The diameter of the stop portion is less than or equal to the diameter of the shaft end face.

9. The flow sensor according to claim 7, characterized in that, Each blade does not extend beyond the axial ends of the center portion at either end along the rotor axis.

10. The flow sensor according to any one of claims 1 to 5, characterized in that, At least the blades of the rotor are magnetic cores, and the sensing element includes an inductor coil; or At least the blades of the rotor are magnets, and the sensing element includes a Hall element.

11. A water heater, characterized in that, It includes an inlet pipe and a flow sensor as described in any one of claims 1-10, the flow sensor being connected to the inlet pipe, the inlet pipe being used to deliver fluid to the flow sensor to drive the rotor to rotate.

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