Magnetic coupling type dynamic balance impeller and manufacturing method

Abstract

The invention provides a magnetic coupling type dynamic balance impeller. The magnetic coupling type dynamic balance impeller comprises an impeller body, magnetic steel, an upper lining and a lower lining. The density of the impeller body is smaller than that of a measurement medium, the impeller body is provided with a balancing weight, and the balancing weight is used for balancing the weight of the impeller body so that the overall mass of the magnetic coupling type dynamic balance impeller can be evenly distributed and the magnetic coupling type dynamic balance impeller can suspend in the measurement medium; the magnetic steel is mounted on the impeller body and is used for transmitting a flow signal of a measurement medium; the upper bushing is mounted at the upper end of the impeller body; and the lower bushing is mounted at the lower end of the impeller body. The low-density impeller body is matched with the balancing weight, so that the overall mass distribution of the magnetic coupling type dynamic balance impeller is uniform, the magnetic coupling type dynamic balance impeller can suspend in a measurement medium to realize dynamic balance, and the balancing weight is easy to adjust, so that fine adjustment can be carried out in a test.

Description

Technical Field

[0001] The invention relates to the field of flow measurement, and in particular to a magnetically coupled dynamic balancing impeller and a manufacturing method thereof. Background Art

[0002] At present, the main material of the impeller used in general dry water meters is ABS, which is composed of an impeller, an impeller shaft, a magnetic steel, etc. The combined impeller is heavy, resulting in large friction resistance and an unstable center of gravity. It is easy to cause unidirectional deviation during the rotation of the impeller, that is, it cannot meet the requirements of high metering levels. Under long-term friction, the bearings and corundum will cause a certain degree of wear, reducing the life of the water meter. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a magnetic coupling type dynamic balancing impeller, which has the characteristic of reducing the weight of the magnetic coupling type dynamic balancing impeller.

[0004] The specific scheme is as follows: A magnetically coupled dynamic balancing impeller comprises an impeller body, a magnetic steel, an upper bushing and a lower bushing;

[0005] The density of the impeller body is less than the density of the measured medium. The impeller body is provided with a counterweight block, which is used to balance the impeller body so that the overall mass distribution of the magnetically coupled dynamic balancing impeller is uniform and can be suspended in the measured medium.

[0006] The magnetic steel is installed on the impeller body and is used to transmit the measurement medium flow signal;

[0007] The upper bushing is installed on the upper end of the impeller body;

[0008] The lower bushing is installed at the lower end of the impeller body.

[0009] Through the above technical solution, the density of the impeller body is less than the density of the measuring medium, which is more convenient for weight balancing; the overall mass of the magnetically coupled dynamically balanced impeller is evenly distributed and can be suspended in water after being weighted by the counterweight block, and the friction can be reduced when the upper bushing and the lower bushing are connected with other components, which plays an important role in improving the metering accuracy and increasing the life of the water meter.

[0010] Preferably, the impeller body (1) is provided with n evenly distributed counterweight blocks (5), and the weight calculation formula of each counterweight block is as follows:

[0011] W 配重 =(V 总 * 测量介质 -W 总 +F 磁 )*ρ 配重 / n(ρ 配重 -ρ 测量介质 )

[0012] V 总 =V 叶轮本体 +V 磁钢 +V 上衬套 +V 下衬套

[0013] W 总 =W 叶轮本体 +W 磁钢 +W 上衬套 +W 下衬套

[0014] F 磁 ≈B2·A / 2·μ0·d

[0015] Where W 配重 is the weight of each counterweight; V 叶轮本体 is the volume of the impeller body; V 磁钢 is the volume of the magnetic steel; V 上衬套 + is the volume of the upper bushing; V 下衬套 is the volume of the lower bushing; W 叶轮本体 is the weight of the impeller body; W 磁钢 is the weight of the magnet; W 上衬套 + is the weight of the upper bushing; W 下衬套 is the weight of the lower bushing; ρ 测量介质 is the density of the measuring medium; ρ 配重 F is the density of the counterweight; 磁 is the magnetic attraction; B is the magnetic field strength, A is the magnetic pole area, μ0 is the magnetic permeability in vacuum, and d is the distance between the magnetic steel and the magnet it is coupled to.

[0016] Through the above technical solution, the weight of the counterweight block can be calculated more conveniently, which is convenient for industrial production.

[0017] Preferably, the impeller body includes a support member and an annular fixing member, the support member is used to support the upper bushing, the annular fixing member is located around the upper bushing and is used to wrap and fix the upper bushing, a first groove is opened on the annular fixing member, the first groove is used to connect the space inside and outside the annular fixing member, the support member is located at the center of the annular fixing member, a plurality of first reinforcing ribs are arranged between the support member and the annular fixing member, a second groove is opened on the first reinforcing rib, and the second groove is used to connect the space on both sides of the first reinforcing rib.

[0018] Through the above technical solution, a first groove is formed on the annular fixing member, and a second groove is formed on the first reinforcing rib, so as to avoid the situation that the annular fixing member is blocked after the bushing is installed, and ensure that the water flow can fill the internal space of the annular fixing member. No air will appear inside the impeller, and weightlessness caused by air can be avoided;

[0019] Preferably, the impeller body also includes an annular reinforcement, the annular fixing member is located inside the annular reinforcement and is coaxially arranged, a plurality of second reinforcing ribs are arranged between the annular fixing member and the annular reinforcement, two of the second reinforcing ribs are provided with magnetic steel mounting grooves, and the magnetic steel mounting grooves are used to install magnetic steel.

[0020] Through the above technical solution, the weight of the impeller body is reduced while the structural strength of the impeller body is enhanced.

[0021] Preferably, a center hole is provided on the impeller body, and the center hole is used for installing a lower bushing.

[0022] Through the above technical solution, the installation structure of the lower bushing is made simpler and convenient for industrial production.

[0023] Preferably, a first through hole and a second through hole are alternately arranged between the two end faces of the impeller body, the first through hole and the second through hole form a stepped surface, a counterweight is installed in the first through hole, a boss is arranged in the first through hole, and the boss cooperates with the stepped surface to fix the counterweight.

[0024] Through the above technical solution, when the counterweight block needs to be replaced, a tool can be used to push the counterweight block out through the second through hole for replacement.

[0025] Another topic is a manufacturing method of a magnetically coupled dynamic balancing impeller, which is as follows:

[0026] S1 manufactures counterweights;

[0027] S2 places the counterweight block in a mold and performs melt injection molding on an injection molding machine to obtain a combination of an impeller body and the counterweight block; S3 respectively installs a magnetic steel (2), an upper bushing (3) and a lower bushing (4) on the impeller body to obtain a magnetically coupled dynamic balancing impeller.

[0028] Through the above technical solution, the combination of the impeller body and the counterweight block can be directly manufactured by injection molding, which reduces the number of production steps.

[0029] Preferably, step 1 comprises the following steps:

[0030] S11 obtains ceramic powder, NaOMe and Si(OEt)4 in proportion and mixes them evenly, wherein the ratio of ceramic powder, NaOMe and Si(OEt4 is 38:56:6;

[0031] The S12 is made into a blank by 3D printing;

[0032] S13: immersing the green body in a NaOH solution so that the NaOH solution is coated on the surface of the green body;

[0033] S14: heat-treating the green body coated with NaOH solution at 1000°C to form a counterweight.

[0034] By using the above technical solution, the processing difficulty is greatly reduced compared with the use of precision-processed metal blocks as counterweights. At the same time, the counterweights processed by this method have better chemical stability.

[0035] Preferably, the specific steps and parameters of melt injection molding in step 2 are as follows:

[0036] S21 polypropylene raw material is dried at 80-100 degrees for 2 hours;

[0037] S22 places the counterweight block in a mold and performs melt injection molding through an injection molding machine. The specific steps and parameters of melt injection molding are as follows: melting temperature is 200°C, injection pressure is 4.2-4.6MPa, holding time is 4.4 seconds, and natural cooling is performed at room temperature of 25°C for 10 seconds. After cooling, the mold is opened and the product is ejected by a push rod. The ejection times are 2 times and the ejection pressure is 5MPa to obtain a combination of the impeller body and the counterweight block.

[0038] Through the above technical solution, the structural strength of the manufactured impeller body is made higher, and at the same time the wall thickness of the impeller body is more uniform, and there will be no problems such as poor shrinkage inside.

[0039] Preferably, the mold in step 2 includes an upper mold and a lower mold, the upper mold is provided with a positioning hole, the lower mold is provided with a positioning column matching the positioning hole, the upper mold is provided with a shaft, the shaft is used to form a first through hole on the impeller body, the lower mold is provided with a push rod, the push rod is used to form a second through hole on the impeller body and to eject the impeller body from the lower mold after opening the mold, and the shaft and the push rod cooperate to clamp the counterweight block on the mold.

[0040] Through the above technical solution, the positioning hole and the positioning column cooperate to facilitate the accurate and stable mold closing of the upper mold and the lower mold. The shaft and the ejector rod cooperate to clamp the counterweight block on the mold, and the impeller body with the counterweight block installed can be obtained after the injection molding is completed, without the installation process of the counterweight block. The ejector rod can form the second through hole and can also eject the product when demolding.

[0041] The beneficial effects of the present invention are:

[0042] 1. The low-density impeller body and the counterweight block make the overall mass distribution of the magnetically coupled dynamic balancing impeller uniform and can be suspended in the measuring medium to achieve dynamic balance. The counterweight block is easy to adjust for fine-tuning during the test.

[0043] 2. The counterweight is installed between the first through hole and the second through hole at the lower part of the impeller body, which can stabilize the bottom center of gravity and ensure the stability of the impeller rotation.

[0044] 3. A first groove is provided on the annular fixing part, and a second groove is provided on the first reinforcing rib to avoid the situation that the annular fixing part is blocked after the bushing is installed, and to ensure that the water flow can fill the internal space of the annular fixing part. No air will appear inside the impeller, and weightlessness caused by air will be avoided.

[0045] 4. Use upper and lower bushings to reduce friction.

[0046] 5. The counterweight is manufactured by 3D printing, which makes it easy to adjust the weight so that fine-tuning can be done during testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0048] in:

[0049] Figure 1 It is a top view of Example 1;

[0050] Figure 2 for Figure 1 AA section view;

[0051] Figure 3 for Figure 1 BB cross-sectional view;

[0052] Figure 4 It is a bottom view of Example 1;

[0053] Figure 5 It is a schematic diagram of the impeller body structure;

[0054] Figure 6 is a top view of the impeller body;

[0055] Figure 7 for Figure 6 CC section view;

[0056] Figure 8 for Figure 6 DD cross-sectional view;

[0057] Fig. 9 Schematic diagram of mold structure Figure 1 ;

[0058] Fig.10 Schematic diagram of mold structure Figure 2 . DETAILED DESCRIPTION

[0059] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from this description, and those skilled in the art can make similar generalizations without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0060] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0061] Example 1

[0062] like Figure 1-8 As shown, a magnetically coupled dynamically balanced impeller includes an impeller body 1, a magnetic steel 2, an upper bushing 3 and a lower bushing 4.

[0063] The magnetic coupling dynamic balancing impeller manufactured in this embodiment is applied to a water meter, and its working environment is water at room temperature. The impeller body 1 of this embodiment is made of polypropylene injection molding.

[0064] The specific structure of the impeller body 1 includes a support member 11, an annular fixing member 12 and an annular reinforcement member 14. A middle hole 15 is provided on one end face of the impeller body 1, and the lower bushing 4 is installed in the middle hole 15. A support member 11 is provided on one end face of the impeller body 1, and the support member 11 is used to support the upper bushing 3. The annular fixing member 12 is located around the upper bushing 3 and is used to wrap and fix the upper bushing 3. The upper bushing 3 is installed in the space formed by the annular fixing member 12, and the end of the upper bushing 3 is in contact with the support member 11.

[0065] The annular fixing member 12 is provided with a first groove 121, which is used to connect the space inside and outside the annular fixing member 12. When installed in water, water can flow into and fill the space inside the annular fixing member 12 through the first groove 121. The support member 11 is located at the center of the annular fixing member 12. A plurality of first reinforcing ribs 18 are arranged between the support member 11 and the annular fixing member 12, and the plurality of first reinforcing ribs 18 are arranged radially. A second groove 181 is provided on the first reinforcing rib 18, which is used to connect the space on both sides of the first reinforcing rib 18. Water can flow between the spaces divided by the first reinforcing rib 18. The annular reinforcing member 14 is arranged outside the annular fixing member 12 and is coaxially arranged. A plurality of second reinforcing ribs 15 are arranged between the annular fixing member 12 and the annular reinforcing member 14. The support member 11, the first reinforcing rib 18, the annular fixing member 12, the second reinforcing rib 15 and the annular reinforcing member 14 form a honeycomb structure, which can reduce the weight of the impeller body 1 while ensuring sufficient structural strength.

[0066] Two of the second reinforcing ribs 13 are provided with magnetic steel installation grooves 131, and the magnetic steel 2 is installed in the magnetic steel installation grooves 131. The magnetic steel is coupled with the magnet on the metering device in the water meter to transmit the water flow signal.

[0067] Six first through holes 16 and six second through holes 17 are staggered between the two end faces of the impeller body 1. Each first through hole 16 corresponds to and is partially connected to one of the second through holes 17. The first through holes 16 and the second through holes 17 form a stepped surface, and a counterweight 5 is installed in the space where the first through holes 16 and the second through holes 17 are staggered. A boss 161 is provided on the inner wall of the first through hole 16, and the boss 161 cooperates with the stepped surface to fix the counterweight 5.

[0068] The counterweight block 5 is used to adjust the weight of the magnetic coupling dynamic balancing impeller so that the magnetic coupling dynamic balancing impeller can be suspended in the water. Assuming that the number of counterweight blocks is n, in this embodiment n=6, the weight calculation formula of each counterweight block is as follows:

[0069] W 配重 =(V 总 * 测量介质 -W 总 +F 磁 )*ρ 配重 / n(ρ 配重 -ρ 测量介质 )

[0070] V 总 =V 叶轮本体 +V 磁钢 +V 上衬套 +V 下衬套

[0071] W 总 =W叶轮本体 +W 磁钢 +W 上衬套 +W 下衬套

[0072] F 磁 ≈B2·A / 2·μ0·d

[0073] Where W 配重 is the weight of each counterweight; V 叶轮本体 is the volume of the impeller body; V 磁钢 is the volume of the magnetic steel; V 上衬套 + is the volume of the upper bushing; V 下衬套 is the volume of the lower bushing; W 叶轮本体 is the weight of the impeller body; W 磁钢 is the weight of the magnet; W 上衬套 + is the weight of the upper bushing; W 下衬套 is the weight of the lower bushing; ρ 测量介质 is the density of the measuring medium; ρ 配重 F is the density of the counterweight; 磁 is the magnetic attraction; B is the magnetic field strength, A is the magnetic pole area, μ0 is the magnetic permeability in vacuum, and d is the distance between the magnetic steel and the magnet it is coupled to.

[0074] A method for manufacturing a magnetically coupled dynamic balancing impeller comprises the following steps:

[0075] S1 manufactures counterweights;

[0076] S11 obtains ceramic powder, NaOMe and Si(OEt)4 in proportion and mixes them evenly, wherein the ratio of ceramic powder, NaOMe and Si(OEt4 is 38:56:6;

[0077] The S12 is made into a blank by 3D printing;

[0078] S13: immersing the green body in a NaOH solution so that the NaOH solution is coated on the surface of the green body;

[0079] S14: heat-treating the green body coated with NaOH solution at 1000°C to form a counterweight.

[0080] S2 Melt Injection Molding

[0081] The S21 polypropylene raw material is dried at 80-100°C for 2 hours.

[0082] S22: placing the counterweight block in a mold and performing melt injection molding by an injection molding machine. The specific steps and parameters of melt injection molding are as follows: melting temperature is 200° C., injection pressure is 4.2-4.6 MPa, holding time is 4.4 seconds, and natural cooling is performed at room temperature of 25° C. for 10 seconds. After cooling, the mold is opened and the product is ejected by an ejector rod. The ejection times are 2 times and the ejection pressure is 5 MPa to obtain a combination of the impeller body and the counterweight block.

[0083] S3 A magnetic steel 2, an upper bushing 3 and a lower bushing 4 are respectively installed on the impeller body to obtain a magnetically coupled dynamic balancing impeller.

[0084] like Figure 9-10 As shown, the injection mold includes an upper mold 61 and a lower mold 62. The upper mold 61 is provided with four positioning holes 611, and the lower mold 62 is provided with four positioning posts 621 that match the positioning holes 611. The lower mold 105 is fixed to the positioning holes 611 of the upper mold 61 through the four positioning posts 621. The upper mold 61 is provided with a shaft 612, and the shaft 612 is used to form a first through hole 16 on the impeller body 1; the lower mold 62 is provided with a push rod 622, and the push rod 622 is used to form a second through hole 17 on the impeller body 1 and to eject the impeller body from the lower mold after the mold is opened. The shaft 612 and the push rod 622 cooperate to clamp the counterweight block on the mold. The mold is opened after the raw material is solidified, and the push rod 622 is used to eject the parts to output the complete product during the mold opening.

[0085] In another embodiment, two mold cavities 63 are provided in the mold, so that two products can be produced by injection molding at the same time.

[0086] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A magnetically coupled dynamic balancing impeller, characterized in that: It comprises an impeller body (1), a magnetic steel (2), an upper bushing (3) and a lower bushing (4); The density of the impeller body (1) is less than the density of the measured medium. The impeller body (1) is provided with a counterweight (5). The counterweight (5) is used for counterweighting the impeller body (1) so that the overall mass distribution of the magnetically coupled dynamic balancing impeller is uniform and the impeller can be suspended in the measured medium. The magnetic steel (2) is mounted on the impeller body (1) and is used to transmit a flow signal of the measuring medium; The upper bushing (3) is mounted on the upper end of the impeller body (1); The lower bushing (4) is installed at the lower end of the impeller body (1).

2. According to claim 1, a magnetically coupled dynamic balancing impeller is characterized in that: The impeller body (1) is provided with n evenly distributed counterweight blocks (5), and the weight calculation formula of each counterweight block is as follows: W 配重 =(V 总 *r 测量介质 -W 总 +F 磁 )*r 配重 / n(p 配重 -r 测量介质 ) V 总 =V 叶轮本体 +V 磁钢 +V 上衬套 +V 下衬套 IN 总 =In 叶轮本体 +W 磁钢 +W 上衬套 +W 下衬套 F 磁 ≈B2 A / 2 μ0 d Where W 配重 is the weight of each counterweight; V 叶轮本体 is the volume of the impeller body; V 磁钢 is the volume of the magnetic steel; V 上衬套 + is the volume of the upper bushing; V 下衬套 is the volume of the lower bushing; W 叶轮本体 is the weight of the impeller body; W 磁钢 is the weight of the magnet; W 上衬套 + is the weight of the upper bushing; W 下衬套 is the weight of the lower bushing; ρ 测量介质 is the density of the measuring medium; ρ 配重 F is the density of the counterweight; 磁 is the magnetic attraction; B is the magnetic field strength, A is the magnetic pole area, μ0 is the magnetic permeability in vacuum, and d is the distance between the magnetic steel and the magnet it is coupled to.

3. The magnetically coupled dynamic balancing impeller according to claim 1, characterized in that: The impeller body (1) comprises a support member (11) and an annular fixing member (12), wherein the support member (11) is used to support an upper bushing (3), the annular fixing member (12) is located around the upper bushing (3) and is used to wrap and fix the upper bushing (3), the annular fixing member (12) is provided with a first groove (121), the first groove (121) is used to connect the space inside and outside the annular fixing member (12), the support member (11) is located at the center of the annular fixing member (12), a plurality of first reinforcing ribs (18) are provided between the support member (11) and the annular fixing member (12), the first reinforcing rib (18) is provided with a second groove (181), the second groove (181) is used to connect the space on both sides of the first reinforcing rib (18).

4. The magnetically coupled dynamic balancing impeller according to claim 3, characterized in that: The impeller body (1) further comprises an annular reinforcement member (14), the annular fixing member (12) being located inside the annular reinforcement member (14) and being coaxially arranged, a plurality of second reinforcement ribs (13) being arranged between the annular fixing member (12) and the annular reinforcement member (14), wherein two of the second reinforcement ribs (13) are provided with magnetic steel mounting grooves (131), and the magnetic steel mounting grooves (131) are used for mounting the magnetic steel (2).

5. The magnetically coupled dynamic balancing impeller according to claim 1, characterized in that: The impeller body (1) is provided with a central hole (15), and the central hole (15) is used for installing a lower bushing (4).

6. The magnetically coupled dynamic balancing impeller according to claim 1, characterized in that: A first through hole (16) and a second through hole (17) are alternately arranged between the two end faces of the impeller body (1); the first through hole (16) and the second through hole (17) form a stepped surface; a counterweight (5) is installed in the first through hole (16); a boss (161) is arranged in the first through hole (16); the boss (161) cooperates with the stepped surface to fix the counterweight (5).

7. A method for manufacturing a magnetically coupled dynamic balancing impeller according to any one of claims 1 to 6, characterized in that: S1 manufactures counterweights; S2 places the counterweight block in a mold and performs melt injection molding on an injection molding machine to obtain a combination of an impeller body and the counterweight block; S3 respectively installs a magnetic steel (2), an upper bushing (3) and a lower bushing (4) on the impeller body to obtain a magnetically coupled dynamic balancing impeller.

8. The method for manufacturing an impeller body according to claim 7, characterized in that: Wherein step 1 comprises the following steps: S11 obtaining ceramic powder, NaOMe and Si(OEt)4 in proportion and mixing them evenly, wherein the ratio of ceramic powder, NaOMe and Si(OEt)4 is 38:56:6; The S12 is made into a blank by 3D printing; S13: immersing the green body in a NaOH solution so that the NaOH solution is coated on the surface of the green body; S14: heat-treating the green body coated with NaOH solution at 1000°C to form a counterweight.

9. The method for manufacturing an impeller body according to claim 7, characterized in that: The specific steps and parameters of melt injection molding in step 2 are as follows: S21 polypropylene raw material is dried at 80-100 degrees for 2 hours; S22 places the counterweight block in a mold and performs melt injection molding through an injection molding machine. The specific steps and parameters of melt injection molding are as follows: melting temperature is 200°C, injection pressure is 4.2-4.6MPa, holding time is 4.4 seconds, and natural cooling is performed at room temperature of 25°C for 10 seconds. After cooling, the mold is opened and the product is ejected by a push rod. The ejection times are 2 times and the ejection pressure is 5MPa to obtain a combination of the impeller body and the counterweight block.

10. The method for manufacturing an impeller body according to claim 7, characterized in that: The mold in step 2 includes an upper mold (61) and a lower mold (62), wherein the upper mold (61) is provided with a positioning hole (611), and the lower mold (62) is provided with a positioning column (621) that matches the positioning hole (611). The upper mold (61) is provided with a shaft (612), and the shaft (612) is used to form a first through hole (16) on the impeller body (1). The lower mold (62) is provided with a push rod (622), and the push rod (622) is used to form a second through hole (17) on the impeller body (1) and to eject the impeller body from the lower mold after the mold is opened. The shaft (612) and the push rod (622) cooperate to clamp the counterweight block on the mold.

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