Mechanical water meter with double magnetic steel open impeller

Abstract

The present application relates to the field of water meter, especially to a mechanical water meter with double magnetic steel open hole impeller, comprising a shell; a movement, the movement is integrally installed in the inside of the shell; the movement comprises an impeller, a counter and a double magnetic steel transmission part connecting the impeller and the counter, the impeller comprises an impeller shaft and a plurality of blades distributed circumferentially on the outside of the impeller shaft, the blades are provided with a fairing, the fairing comprises an opening through the blade in the circumferential direction perpendicular to the impeller shaft, the inlet edge of the flow face of the opening and the outlet edge of the back flow face are both provided with a flow angle; the double magnetic steel transmission part is a radial two-pole magnetic circuit coupling structure, the double magnetic steel transmission part is used for reducing the rotational inertia of the impeller, reducing the starting torque threshold of the impeller, and driving the low torque of the impeller after the resistance reduction of the fairing, and converting it into the output of the counter; through the bidirectional collaborative design of the double magnetic steel transmission part and the fairing, the micro-flow measurement capacity and the transmission stability of the water meter are improved.

Description

Technical Field

[0001] This invention relates to the field of water meters, and in particular to a mechanical water meter employing a double-magnetic perforated impeller. Background Technology

[0002] Currently, the mainstream magnetic drive solution for dry water meters in the industry mainly uses paired annular multipole magnets. Some technologies also adopt a dual-magnet drive solution. The dual-magnet solution, through the lightweight structure of two independent permanent magnets, can effectively reduce the overall rotational inertia of the impeller and has the potential to optimize micro-flow metering capabilities. Therefore, it is used in small quantities in precision metering scenarios with low water flow disturbance and high water quality, as well as in laboratory testing conditions. However, existing dry water meters using dual-magnet and annular magnet solutions still have certain technical shortcomings in conventional civilian water supply metering scenarios:

[0003] First, the inherent limitation of the dual-magnet scheme stems from its radial bipolar symmetrical coupling structure. The dual magnets transmit power only through two symmetrical magnetic coupling points, lacking the fault tolerance of the full circumferential coupling of the annular multi-pole magnets. This makes it extremely sensitive to the radial oscillation and coaxiality deviation of the impeller. In actual water supply scenarios, the impeller is easily subjected to the impact of water flow and disturbance from tiny impurities in the water, which can cause radial oscillation. This oscillation will directly lead to circumferential unevenness in the coupling air gap of the dual magnets, causing large fluctuations in coupling torque. This can result in metering errors or even cause the magnets to lose synchronization or decouple, thus losing the metering function.

[0004] Secondly, while mainstream toroidal multipole magnets offer higher transmission tolerance, they are bulky and heavy. When combined with an impeller, their rotational inertia increases significantly. In typical residential micro-flow scenarios such as household dripping or minor leaks in the pipe network, the weak water flow cannot overcome the starting torque threshold created by the high inertia. This results in the water meter having no metering response for micro-flows less than 1L / h, becoming a blind spot for measuring water supply leakage. Therefore, there is an urgent need to develop a dry-type water meter that can simultaneously overcome the shortcomings of the toroidal magnet solution in terms of micro-flow metering capability and solve the problem of transmission instability caused by impeller radial oscillation interference in the dual-magnet solution, in order to meet the full-condition usage requirements of conventional residential water supply metering. Summary of the Invention

[0005] In view of the problems of insufficient micro-flow metering capability of the annular magnet scheme and the susceptibility of the dual magnet scheme to transmission instability caused by impeller radial oscillation interference in the above-mentioned or existing technologies, this invention is proposed.

[0006] Therefore, the purpose of this invention is to provide a mechanical water meter employing a double-magnetic perforated impeller.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] A mechanical water meter employing a double-magnet, perforated impeller includes,

[0009] shell;

[0010] The movement, which is integrally installed inside the housing, includes,

[0011] The impeller, the counter, and the double-magnetic transmission unit connecting the impeller and the counter, wherein the impeller includes an impeller shaft and a plurality of blades circumferentially distributed on the outer side of the impeller shaft, and the blades are provided with...

[0012] The rectifying section includes an opening that circumferentially penetrates the blades in a direction perpendicular to the impeller shaft. The inlet edge of the opening on the front side and the outlet edge on the back side are both provided with guide angles.

[0013] The dual-magnetic-steel transmission unit is a radial two-pole magnetic circuit coupling structure. The dual-magnetic-steel transmission unit is used to reduce the impeller rotational inertia, reduce the impeller starting torque threshold, and convert the low-torque drive of the impeller after the resistance reduction of the rectifier into the counter output.

[0014] As a preferred embodiment of the mechanical water meter of the present invention using a double-magnetic steel open-type impeller, the double-magnetic steel transmission part includes a lower magnet group and an upper magnet group arranged coaxially. Both the lower magnet group and the upper magnet group are composed of two independent permanent magnets. The two permanent magnets of the lower magnet group are symmetrically embedded in the top of the impeller hub at 180°.

[0015] As a preferred embodiment of the mechanical water meter of the present invention using a double-magnetic steel open-type impeller, the two permanent magnets of the upper magnet group are symmetrically arranged at 180° on the outside of the input shaft of the counter and are fixedly connected to the input shaft of the counter.

[0016] As a preferred embodiment of the mechanical water meter of the present invention using a double-magnetic steel perforated impeller, wherein: the perforation is circular, only one perforation is opened on the blade, a gear cover is fixedly installed on the outside of the counter, an impeller box is fixedly installed on the gear cover, the impeller box is covered on the outside of the impeller, and several circumferentially distributed guide grooves are opened on the outside of the impeller box, and the center height of the perforation is aligned with the center height of the guide groove in the height direction of the blade.

[0017] As a preferred embodiment of the mechanical water meter of the present invention using a double-magnetic steel perforated impeller, wherein: the guiding angle is a continuous arc-shaped guiding angle around the entire circumference, the radius of the arc-shaped guiding angle at the inlet of the flow-facing side is 15%-25% of the opening diameter, the radius of the arc-shaped guiding angle at the outlet of the back-flowing side is 10%-15% of the opening diameter, and the radius of the arc-shaped guiding angle at the flow-facing side is greater than the radius of the arc-shaped guiding angle at the back-flowing side.

[0018] As a preferred embodiment of the mechanical water meter of the present invention using a double-magnetic steel perforated impeller, wherein: the arc-shaped guide angle is a continuous 360° concave arc transition fillet with the center of the fillet located on the central axis of the opening.

[0019] As a preferred embodiment of the mechanical water meter of the present invention using a double-magnet open-type impeller, wherein: the two independent permanent magnets of the lower magnet group are arranged with opposite poles, and the two independent permanent magnets of the upper magnet group are opposite poles to the lower magnet group, forming a directional closed radially coupled magnetic circuit.

[0020] As a preferred embodiment of the mechanical water meter of the present invention, which employs a double-magnetic steel perforated impeller, the permanent magnet of the lower magnet group is embedded in the impeller hub.

[0021] As a preferred embodiment of the mechanical water meter of the present invention using a double-magnetic steel perforated impeller, the number of blades is 7-10, and the opening size and arc guide angle parameters on all blades are consistent and uniformly and symmetrically distributed along the circumferential direction of the impeller axis.

[0022] As a preferred embodiment of the mechanical water meter of the present invention, which uses a double-magnetic steel perforated impeller, the outer casing is provided with an inlet and an outlet.

[0023] The beneficial effects of the mechanical water meter of the present invention, which employs a double-magnet perforated impeller, are as follows:

[0024] In this application, the rectifier section balances the pressure difference between the front and back surfaces of the blades and eliminates water eddies through the through-holes in the blades and the arc-shaped guide angle. This not only significantly reduces the hydraulic resistance of the impeller rotation but also fundamentally suppresses the radial oscillation of the impeller and the excitation of the water flow. It completely overcomes the inherent defects of the dual-magnetic pole coupling structure, which is sensitive to oscillation and prone to slippage and loss of synchronization, and provides a core prerequisite for stable magnetic circuit coupling. The dual-magnetic transmission section significantly reduces the overall rotational inertia of the impeller through a lightweight symmetrical dual permanent magnet structure, eliminates the starting torque threshold for micro-flow, and completely transforms the hydraulic optimization effect of the rectifier section into metering performance. Through the bidirectional collaborative design of the dual-magnetic transmission section and the rectifier section, the problem of balancing micro-flow metering capability and transmission stability is solved. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0027] Figure 2 This is an exploded view of the three-dimensional structure of the present invention.

[0028] Figure 3 This is a three-dimensional structural cross-sectional view of the watch case, watch cover, and gear cover of the present invention.

[0029] Figure 4 For the present invention Figure 3 A magnified view of part A in the middle.

[0030] Figure 5 This is a three-dimensional structural diagram of the opening, the frontal surface, and the backal surface of the present invention.

[0031] Figure 6 This is a three-dimensional structural diagram of the counter and upper magnet assembly of the present invention.

[0032] Figure 7 This is a three-dimensional structural diagram of the impeller box and guide groove of the present invention.

[0033] In the diagram: 1. Outer casing; 11. Watch case; 12. Watch cover; 2. Movement; 21. Counter; 22. Gear cover; 23. Double magnet drive unit; 231. Upper magnet assembly; 232. Lower magnet assembly; 24. Impeller; 241. Rectifier; 2411. Opening; 2412. Frontal surface; 2413. Backal surface; 242. Impeller shaft; 243. Blade; 25. Impeller box; 251. Guide channel; 3. Inlet; 4. Outlet. Detailed Implementation

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] Reference Figures 1-7 This embodiment provides a mechanical water meter using a double-magnetic perforated impeller, which can improve the water meter's micro-flow measurement capability and transmission stability. It includes an outer shell 1 consisting of a casing 11 and a cover 12 connected to each other; a mechanism 2, which is installed inside the outer shell 1; the mechanism 2 includes an impeller 24, a counter 21, and a double-magnetic transmission part 23. The impeller 24 includes an impeller shaft 242 and a plurality of blades 243 circumferentially distributed outside the impeller shaft 242. The blades 243 are provided with a rectifier 241, which includes an opening 2411 that circumferentially passes through the blades 243 in a direction perpendicular to the impeller shaft 242. The inlet edge of the flow-facing surface 2412 and the outlet edge of the backflow surface 2413 of the opening 2411 are both provided with guide angles.

[0036] The opening 2411 is used to balance the pressure difference between the front surface 2412 and the back surface 2413 of the blade 243, and together with the guide angle, it eliminates the separation of the water flow boundary layer and local eddies, thereby reducing the rotational resistance of the impeller 24 and suppressing the radial oscillation of the impeller 24; the double magnet drive part 23 is used to reduce the rotational inertia of the impeller 24, lower the starting torque threshold, and convert the low torque drive of the impeller 24 after the resistance reduction by the rectifier part 241 into the output of the counter 21.

[0037] It should be noted that the impeller 24 is the component inside the water meter that rotates directly under the impact of the water flow. Its rotational speed is proportional to the water flow rate and it is the initial stage for converting water flow energy into mechanical energy. The counter 21 is a device used to accumulate the number of rotations of the impeller 24 and convert it into readable flow data, which is achieved through a gear set. The double magnet transmission part 23 is a mechanism that transmits power using the principle of magnetic coupling. It transmits the rotation of the impeller 24 to the counter 21 through the action of a magnetic field, realizing non-contact transmission.

[0038] The impeller shaft 242 is the central axis of rotation of the impeller 24, around which the impeller 24 rotates; the blades 243 are structures on the impeller 24 used to capture the energy of the water flow, and can be distributed at a certain angle to efficiently convert the kinetic energy of the water flow into the rotation of the impeller 24; the rectifier 241 is a special structure set on the blades 243, which optimizes the flow pattern of the water flow when passing through the blades 243, reduces resistance, and improves the rotation efficiency of the impeller 24.

[0039] The opening 2411 is a specific form of the rectifying part 241. The opening 2411 can be designed as an ellipse, a square or other geometric shape, and multiple openings 2411 can be provided on each blade 243, thereby allowing some water flow to pass directly through the blade 243, thereby changing the water flow distribution on the surface of the blade 243. The inlet edge of the front surface 2412 refers to the edge of the opening 2411 on the side where the water flow enters. The outlet edge of the back surface 2413 refers to the edge of the opening 2411 on the side where the water flow leaves. The guide angle is a transition structure set at the edge of the opening 2411. Its function is to guide the water flow smoothly into and out of the opening 2411, further reducing water flow resistance and reducing vortex generation.

[0040] Moment of inertia is a physical quantity that measures an object's ability to resist changes in its rotational state. The smaller the moment of inertia, the easier it is for the object to start and accelerate. The starting torque threshold is the minimum torque required to make the impeller 24 start rotating. The lower the starting torque threshold, the stronger the water meter's response to small flow rates. Resistance reduction refers to reducing the resistance generated by the water flow on the impeller 24 through optimized structural design. Low torque drive means that the impeller 24 can be effectively rotated under a relatively small torque.

[0041] Reference Figure 2 , Figure 3 and Figure 7 A gear cover 22 is fixedly installed on the outside of the counter 21. An impeller box 25 is fixedly installed on the gear cover 22. The impeller box 25 covers the outside of the impeller 24. Several circumferentially distributed guide grooves 251 are opened on the outside of the impeller box 25. A water inlet 3 and a water outlet 4 are opened on the casing 11.

[0042] Reference Figure 3 and Figure 4The dual-magnetic transmission unit 23 includes a lower magnet group 232 and an upper magnet group 231 arranged coaxially. Both the lower magnet group 232 and the upper magnet group 231 are composed of two independent permanent magnets. The two permanent magnets of the lower magnet group 232 are symmetrically embedded at 180° on the top of the hub of the impeller 24 and rotate coaxially with the impeller 24.

[0043] Reference Figure 3 and Figure 4 The two permanent magnets of the upper magnet group 231 are symmetrically arranged at 180° on the outside of the input shaft of the counter 21 and are fixedly connected to the input shaft of the counter 21; the upper magnet group 231 and the lower magnet group 232 form a radially symmetrical bipolar coupled magnetic circuit, and achieve zero-slip synchronous transmission through non-contact magnetic coupling.

[0044] Reference Figure 3 , Figure 4 and Figure 5 The two independent permanent magnets of the lower magnet group 232 are arranged with opposite poles, and the two independent permanent magnets of the upper magnet group 231 are opposite poles to the lower magnet group 232, forming a directional closed radially coupled magnetic circuit; the two independent permanent magnets of the lower magnet group 232 are arranged with opposite poles, and the two independent permanent magnets of the upper magnet group 231 are opposite poles to the lower magnet group 232, forming a directional closed radially coupled magnetic circuit; the permanent magnets of the lower magnet group 232 are embedded in the hub of the impeller 24.

[0045] It should be noted that the radial bipolar magnetic circuit coupling structure of the dual-magnet drive unit 23 can efficiently drive the upper magnet group 231 to rotate even when the torque generated by the impeller 24 is low, thereby driving the input shaft of the counter 21 to count; thus significantly reducing transmission loss and starting torque threshold; after receiving the rotation signal from the dual-magnet drive unit 23, the counter 21 converts it into readable flow data for cumulative display; by reducing the rotational starting resistance of the impeller 24 through the rectifier 241, and by using the dual-magnet drive unit 23 to reduce the rotational inertia of the impeller 24 and achieve efficient transmission, it is ensured that the water meter can not only operate stably under normal flow, but also respond sensitively and accurately under small flow, effectively solving the defect of insufficient micro-flow measurement capability of existing water meters using the annular magnet scheme, and solving the problem of transmission instability caused by radial oscillation interference of the impeller 24 in the dual-magnet scheme.

[0046] In some embodiments described above in this application, a flow rectifying part 241 is provided on the blade 243. The flow rectifying part 241 includes an opening 2411 and is provided with a guide angle to reduce resistance. However, in practical applications, the number, position and shape of the opening 2411 on the blade 243 have a significant impact on the flow rectification effect, the balance of the impeller 24 and the metering accuracy of the water meter. If the number of openings 2411 is too large or the position is improper, it may cause water flow turbulence, affect the stable rotation of the impeller 24, and thus reduce the metering accuracy of the water meter.

[0047] In this regard, refer to Figure 3 , Figure 4 , Figure 5 and Figure 7 This application further proposes that only one circular opening 2411 is opened on the blade 243, and the opening 2411 is aligned with the center height of the guide groove 251 in the height direction of the blade 243.

[0048] It should be noted that the blade 243 has only one circular opening 2411, which means that each blade 243 has only one circular hole for water to pass through. The single opening design avoids the complex flow pattern and eddies that may be caused by the water flow being dispersed through multiple holes on the blade 243, making the water flow path more stable.

[0049] The opening 2411 is aligned with the center height of the guide groove 251 in the height direction of the blade 243. This means that the center height of the circular opening 2411 is aligned with the center height of the water outlet of the guide groove 251 distributed circumferentially on the impeller box 25. The guide groove 251 is used to guide the water flow to form a tangential jet and drive the impeller 24 to rotate. The area of ​​the blade 243 corresponding to the center of the guide groove 251 is the area where the water flow impact is most concentrated and the pressure difference between the front surface 2412 and the back surface 2413 is the largest. This allows the pressure difference balancing effect of the through opening 2411 to be effectively utilized, thereby reducing the hydraulic resistance of the impeller 24 rotation.

[0050] Meanwhile, the design of the center of the opening 2411 corresponding to the center of the guide groove 251 allows the water to flow smoothly in and out of the opening 2411, avoiding water flow deflection and local turbulence caused by the position of the opening 2411 deviating from the mainstream impact zone. Furthermore, the arc-shaped guide angle eliminates water flow boundary layer separation and reduces the radial oscillation of the impeller 24 caused by water flow excitation. Moreover, the openings of all blades 243 are matched with the center of the guide groove 251, so that the thrust generated by the water flow through the opening 2411 on the blades 243 can be evenly distributed on the surface of the blades 243, effectively offsetting the possible eccentric torque. This ensures that the impeller 24 rotates more smoothly and without shaking under the water flow drive, thereby reducing the rotational resistance of the impeller 24. This allows the dual magnet transmission part 23 to more efficiently convert the low torque drive of the impeller 24 into the accurate output of the counter 21, thereby improving the metering accuracy and stability of the counter 21.

[0051] In some embodiments described above in this application, a single circular opening 2411 is provided on the blade 243 of the impeller 24. The opening 2411 is aligned with the center height of the guide groove 251 in the height direction of the blade 243. Furthermore, the inlet edge of the frontal surface 2412 and the outlet edge of the backal surface 2413 of the opening 2411 are both provided with a continuous arc-shaped guide angle around the entire circumference. However, in practical applications, if the specific parameters of the arc-shaped guide angle are not properly designed, it may cause unnecessary eddies or resistance to be generated when the water flows through the opening 2411, thereby affecting the low-torque starting performance of the impeller 24 and the metering accuracy of the water meter.

[0052] In this regard, refer to Figure 3 , Figure 4 , Figure 5 and Figure 7 This application further proposes that the radius of the arc-shaped guide angle at the inlet of the frontal surface 2412 is 15%-25% of the diameter of the opening 2411, and the radius of the arc-shaped guide angle at the outlet of the backal surface 2413 is 10%-15% of the diameter of the opening 2411, and the radius of the arc-shaped guide angle of the frontal surface 2412 is greater than the radius of the arc-shaped guide angle of the backal surface 2413.

[0053] It should be noted that the radius of the arc-shaped guide angle at the inlet of the upstream face 2412 is limited to 15%-25% of the diameter of the opening 2411. This is to optimize the hydrodynamic characteristics of the water flow entering the opening 2411. This range ensures that the water flow can enter the opening 2411 with a smooth transition, avoiding impacts, separation, and eddies caused by abrupt changes at the inlet of the opening 2411, thereby reducing energy loss when the water enters the opening 2411. The radius of the arc-shaped guide angle at the outlet of the downstream face 2413 is... The diameter is limited to 10%-15% of the diameter of the opening 2411. Its function is to reduce the wake and negative pressure zone generated when the water flows away from the blade 243, guide the water flow to leave the opening 2411 smoothly, and further reduce the overall water resistance of the blade 243. Therefore, through the design of the circular opening 2411 and the arc-shaped guide angle, the rotational inertia and starting torque threshold of the impeller 24 are greatly reduced, ensuring that the impeller 24 can start even under extremely low water flow driving force, thereby converting low torque drive into the output of the counter 21.

[0054] Furthermore, the radius of the arc-shaped guide angle on the upstream face 2412 is larger than that on the downstream face 2413. This asymmetric design is an optimization based on the difference in the hydrodynamic effects experienced by the water flow when entering and leaving the opening 2411: a smoother transition is usually required at the inlet to overcome the initial impact and guide the water flow, while the outlet focuses on smooth separation, so the inlet guide angle is designed to be larger.

[0055] In some embodiments described above in this application, the radius of the arc-shaped guide angle at the inlet of the upstream face 2412 is proposed to be 15%-25% of the diameter of the opening 2411, and the radius of the arc-shaped guide angle at the outlet of the downstream face 2413 is proposed to be 10%-15% of the diameter of the opening 2411, with the radius of the arc-shaped guide angle of the upstream face 2412 being larger than that of the arc-shaped guide angle of the downstream face 2413. However, merely specifying the radius and existence of the arc-shaped guide angle may not be sufficient to fully optimize the hydrodynamic characteristics of the water flow through the opening 2411, especially when it is necessary to minimize resistance to improve the sensitivity and metering accuracy of the counter 21. If the specific geometry and positioning of the guide angle are not precise enough, local eddies or uneven pressure distribution may still be generated when the water flows through the opening 2411, thereby affecting the low-torque start-up performance and overall metering stability of the impeller 24.

[0056] In this regard, refer to Figure 3 , Figure 4 , Figure 5 and Figure 7 This application further proposes that the arc-shaped guide angle is a continuous concave arc transition fillet with a full circumference of 360°, and the center of the fillet is located on the central axis of the opening 2411.

[0057] It should be noted that the 360° continuous concave arc transition fillet means that the flow angle presents a smooth, concave arc transition on the entire circumference of the opening 2411; its function is to provide a smooth inlet and outlet path for water flow, thereby minimizing the energy loss and eddies caused by the abrupt change in cross-section when the water flows into or out of the opening 2411, thus reducing fluid resistance.

[0058] The center of the fillet is located on the central axis of the opening 2411, which defines the geometric center of the aforementioned full-circumference circular arc transition fillet as coinciding with the central axis of the circular opening 2411. This coaxial design ensures that the water flow receives a uniform guiding effect when passing through the opening 2411, regardless of which direction it enters or exits. This eliminates the water flow imbalance or local resistance differences that may be caused by the eccentricity of the guiding angle, thereby ensuring the stability and efficiency of the impeller 24 under water flow drive. This allows the impeller 24 to rotate stably even under extremely low water flow driving force, further reducing the starting torque threshold and rotational inertia of the impeller 24, thereby further improving the metering sensitivity and accuracy of the counter 21 at low flow rates.

[0059] In some embodiments described above, the impeller 24 has a flow rectifying section 241 on its blades 243. This flow rectifying section 241 includes a circular opening 2411, and both the inlet edge of the flow-facing side 2412 and the outlet edge of the flow-reversing side 2413 of the opening 2411 have a continuous arc-shaped guide angle around the entire circumference. However, in practical applications, if the number of blades 243, the size of the opening 2411, the arc-shaped guide angle parameters, and the distribution of the blades 243 lack optimization and uniformity, it may lead to uneven force exerted by the water flow on the impeller 24, resulting in unstable rotation of the impeller 24 and decreased measurement accuracy. Especially under low flow velocity conditions, the sensitivity and accuracy of the counter 21 are difficult to guarantee.

[0060] In this regard, refer to Figure 3 , Figure 4 , Figure 5 and Figure 7 This application further proposes that the number of blades 243 is 7-10, and the size of the openings 2411 and the arc guide angle parameters on all blades 243 are the same, and they are evenly and symmetrically distributed along the circumference of the impeller shaft 242.

[0061] It should be noted that the number of blades 243 is one of the key parameters affecting the hydraulic performance of the impeller 24. Too few blades 243 will result in the impeller 24 not being able to obtain sufficient driving torque or having poor rotational stability at low flow rates. Too many blades 243 will increase water flow resistance and reduce the rotational efficiency of the impeller 24. Limiting the number of blades 243 to 7-10 optimizes the contact area and interaction frequency between the blades 243 and the water flow, ensuring sufficient driving torque while reducing water flow resistance, thereby improving the overall hydraulic efficiency and rotational stability of the impeller 24. The opening 2411 and its arc-shaped guide angle are the core features of the rectifying part 241. They work together to reduce resistance and guide the water flow. If there are differences between different blades 243, the resistance or driving torque generated when the water flows through different blades 243 will be inconsistent, which will lead to the impeller 24 being unbalanced and rotating unbalancedly. By ensuring the consistency of the opening 2411 and its arc-shaped guide angle, it can be ensured that each blade 243 obtains the same hydrodynamic response in the water flow, thereby providing a uniform and stable driving force for the impeller 24.

[0062] The circumferential distribution of blades 243 directly affects the dynamic balance performance of impeller 24. If the blades 243 are unevenly or asymmetrically distributed, the impeller 24 will generate an unbalanced torque during rotation, resulting in vibration. By uniformly and symmetrically distributing the blades, it can be ensured that the impeller 24 can maintain good dynamic balance at any speed, making the resultant torque generated by the water flow on the impeller 24 more stable, thereby ensuring the smooth rotation of the impeller 24.

[0063] Through the above specific implementation methods, the impeller 24 can rotate smoothly with extremely low starting torque under the drive of water flow, thereby providing a stable input signal to the dual magnet drive unit 23. This enables the low torque rotation of the impeller 24 to be efficiently converted into the accurate output of the counter 21, thereby ensuring that the counter 21 can maintain high sensitivity and high measurement accuracy over a wide flow velocity range, especially under low flow velocity conditions.

[0064] In practical use, water flows into the inner cavity of the water meter from the inlet 3 of the casing 11. After being rectified by the guide grooves 251 distributed around the impeller box 25, it forms a uniform tangential water flow, which smoothly impacts the working surface of the blades 243, converting the kinetic energy of the water into the rotational mechanical energy of the impeller 24.

[0065] During the process of water flow impacting the blade 243, the rectifier 241 simultaneously plays a hydraulic optimization role: part of the high-pressure water flow on the upstream face 2412 of the blade 243 acts on the blade 243 to drive the impeller 24 to rotate, and the other part flows smoothly into the opening 2411 on the blade 243 through the arc-shaped guide angle of the upstream face 2412, and then smoothly merges into the low-pressure area on the downstream side of the blade 243 through the arc-shaped guide angle of the downstream face 2413; through the pressure difference balancing effect of the opening 2411, combined with the full-circumference arc-shaped guide angle, the boundary layer separation and local eddies of the water flow through the opening are eliminated, which reduces the hydraulic resistance of the impeller 24 rotation from the root and suppresses the radial oscillation of the impeller 24 caused by water flow excitation, so that the impeller 24 can maintain a coaxial and stable rotation state in the entire flow range, which provides a basis for the stable coupling of the double magnet drive unit 23.

[0066] When the impeller 24 rotates, it synchronously drives the lower magnet assembly 232, which is embedded in the top of the hub, to rotate coaxially. The lower magnet assembly 232 and the upper magnet assembly 231 achieve non-contact magnetic synchronous transmission through a radially closed coupling magnetic circuit. The lightweight structure of the double magnets significantly reduces the overall rotational inertia of the impeller 24. Combined with the low rotational resistance brought by the rectifier 241, even in the case of micro-flow scenarios such as household dripping or minor leaks in the pipe network, the weak water flow power can drive the impeller 24 to start smoothly and rotate continuously. Moreover, the sway suppression effect of the rectifier 241 ensures that the coupling air gap of the upper and lower magnet assemblies 232 is always uniform and stable, completely avoiding the torque fluctuation and slippage problems that may be caused by the swaying of the impeller 24 in the existing double magnet solution. It can still achieve slippage-free synchronous transmission under extremely low torque, accurately and losslessly transmitting the micro-flow rotation of the impeller 24 to the upper magnet assembly 231.

[0067] The upper magnet assembly 231 synchronously drives the input shaft of the counter 21 to rotate. Through the gear transmission mechanism inside the counter 21, the number of rotations of the impeller 24 is converted into the corresponding water flow data, completing the cumulative measurement and display. After the energy exchange is completed, the water flows through the inner cavity of the impeller box 25 and the flow channel of the meter casing 11, and finally flows out of the water meter from the outlet 4.

[0068] Throughout the entire operation, the resistance reduction and sway suppression functions of the rectifier 241 completely compensate for the inherent defect of the dual-magnetic steel transmission part 23 being sensitive to the sway of the impeller 24. The low inertia and high synchronization transmission characteristics of the dual-magnetic steel transmission part 23 efficiently transform the hydraulic optimization effect of the rectifier 241 into micro-flow metering capability. The two work together to overcome the pain points of the micro-flow metering blind zone of the existing dry water meter using ring magnet transmission and the poor transmission stability of the dual-magnetic steel scheme. Accurate and stable metering can be achieved under all operating conditions of dripping micro-flow, daily rated flow and peak overload flow in civil water supply.

[0069] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A mechanical water meter employing a dual magnetic steel open impeller, characterized by: include, Outer shell (1); Movement (2), the movement (2) is integrally installed inside the outer casing (1); the movement (2) includes, The impeller (24), counter (21), and double magnet drive unit (23) connecting the impeller (24) and the counter (21) are provided. The impeller (24) includes an impeller shaft (242) and a plurality of blades (243) circumferentially distributed on the outside of the impeller shaft (242). The blades (243) are provided with... The rectifying section (241) includes an opening (2411) that circumferentially penetrates the blade (243) in a direction perpendicular to the impeller shaft (242). The inlet edge of the front surface (2412) and the outlet edge of the back surface (2413) of the opening (2411) are both provided with guide angles. The dual-magnetic steel transmission unit (23) is a radial two-pole magnetic circuit coupling structure. The dual-magnetic steel transmission unit (23) is used to reduce the rotational inertia of the impeller (24), reduce the starting torque threshold of the impeller (24), and convert the low-torque drive of the impeller (24) after the resistance reduction by the rectifier (241) into the output of the counter (21).

2. The mechanical water meter employing a dual magnetic steel open impeller as set forth in claim 1, wherein: The dual-magnetic transmission unit (23) includes a lower magnet group (232) and an upper magnet group (231) arranged coaxially. Both the lower magnet group (232) and the upper magnet group (231) are composed of two independent permanent magnets. The two permanent magnets of the lower magnet group (232) are symmetrically embedded at 180° on the top of the impeller (24) hub.

3. The mechanical water meter employing a dual magnetic steel open impeller as set forth in claim 2, wherein: The two permanent magnets of the upper magnet assembly (231) are symmetrically arranged at 180° on the outside of the input shaft of the counter (21) and are fixedly connected to the input shaft of the counter (21).

4. The mechanical water meter employing dual magnetic steel open impeller of claim 1, wherein: The opening (2411) is circular. Only one opening (2411) is opened on the blade (243). A gear cover (22) is fixedly installed on the outside of the counter (21). An impeller box (25) is fixedly installed on the gear cover (22). The impeller box (25) covers the outside of the impeller (24). Several circumferentially distributed guide grooves (251) are opened on the outside of the impeller box (25). The opening (2411) is aligned with the center height of the guide groove (251) in the height direction of the blade (243).

5. The mechanical water meter employing dual magnetic steel open impeller as defined in claim 4, wherein: The guiding angle is a continuous arc-shaped guiding angle around the entire circumference. The radius of the arc-shaped guiding angle at the inlet of the frontal surface (2412) is 15%-25% of the diameter of the opening (2411), and the radius of the arc-shaped guiding angle at the outlet of the backal surface (2413) is 10%-15% of the diameter of the opening (2411). The radius of the arc-shaped guiding angle of the frontal surface (2412) is greater than that of the arc-shaped guiding angle of the backal surface (2413).

6. The mechanical water meter with a double-magnetic perforated impeller as described in claim 5, characterized in that: The arc-shaped guide angle is a continuous concave arc transition fillet with a full circumference of 360°, and the center of the fillet is located on the central axis of the opening (2411).

7. The mechanical water meter employing dual magnetic steel open impeller as defined in claim 3 wherein: the impeller is formed of a single piece of material. The two independent permanent magnets of the lower magnet group (232) are arranged with opposite poles, and the two independent permanent magnets of the upper magnet group (231) are opposite poles to the lower magnet group (232), forming a directional closed radially coupled magnetic circuit.

8. The mechanical water meter employing dual magnetic steel open impeller as defined in claim 7 wherein: The permanent magnets of the lower magnet assembly (232) are embedded in the impeller (24) hub.

9. The mechanical water meter employing dual magnetic steel open impeller of claim 1, wherein: The number of blades (243) is 7-10. The size of the opening (2411) and the arc guide angle parameters on all blades (243) are the same, and they are evenly and symmetrically distributed along the circumference of the impeller shaft (242).

10. The mechanical water meter employing dual magnetic steel open impeller of claim 1, wherein: The outer shell (1) is provided with a water inlet (3) and a water outlet (4).

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