Positive displacement flowmeter

Abstract

The application relates to the technical field of volumetric flowmeters, and provides a volumetric flowmeter which comprises a shell and two mutually meshed rotors, the shell is a rotor accommodating chamber, and the two rotors are accommodated in the rotor accommodating chamber; elastic fins are arranged on the circumferential inner wall of the rotor accommodating chamber, the fins are uniformly distributed along the inner wall of the rotor accommodating chamber, and the fins are in sliding contact with the rotors when the rotors rotate; or, the rotor tooth valleys of the rotors are provided with uniformly distributed elastic fins, the fins on the rotor tooth valleys are in sliding contact with the rotor tooth crests of the other rotors when the rotors rotate; or, the rotor tooth crests of the rotors are provided with uniformly distributed elastic fins, and the fins on the rotor tooth crests are in sliding contact with the rotor tooth valleys of the other rotors when the rotors rotate. The application sets the elastic fins on the matching surfaces of the components of the volumetric flowmeter, ensures the sealing between the components, reduces the machining precision requirement of the components, and reduces the manufacturing cost.

Description

Technical Field

[0001] This application relates to the field of volumetric flow meter technology, and particularly to a volumetric flow meter. Background Technology

[0002] A positive displacement flow meter uses a fixed volume to repeatedly measure the volume of fluid passing through it. Therefore, a standard volume must exist within the flow meter, commonly referred to as its "measuring space" or "measuring chamber." This space is formed by the inner wall of the instrument housing and the rotating parts of the flow meter. The working principle of a positive displacement flow meter is as follows: as fluid passes through the flow meter, a pressure difference is created between the inlet and outlet. The rotating parts of the flow meter (rotor) rotate under this pressure difference, discharging the fluid from the inlet to the outlet. In this process, the fluid repeatedly fills the flow meter's "measuring space" and is then continuously sent to the outlet. Under given flow meter conditions, the volume of this measuring space is fixed; by measuring the number of rotor rotations, the cumulative volume of fluid passing through the flow meter can be obtained. If the fixed standard volume of the measuring space is V, and the fixed standard volume of fluid discharged through the flow meter within a certain time interval is n, then the total volume of the measured fluid is Q = nV. By using a counter to measure the number of rotor rotations n, the flow rate Q of the fluid being measured can be displayed.

[0003] Elliptical gear flow meters, Roots flow meters, and dual rotor flow meters are three types of positive displacement flow meters driven by the energy of the fluid, requiring no external power source. All three types of positive displacement flow meters consist of a core component housing and two rotors that mesh with each other during rotation, residing within the housing's containment space. Currently, the rotors (corresponding to elliptical gears, Roots, and standard spur gears, respectively) and housings of these three types of positive displacement flow meters are rigid structures. Fluid or gas measurement requires a tight fit between the two rotors and between the rotors and the housing. However, this tight fit necessitates strict control of component clearances. Excessive clearances can lead to liquid or gas leakage, reducing the flow meter's measurement accuracy; conversely, insufficient clearances require extremely high machining precision, increasing manufacturing costs. Furthermore, currently, none of these three types of positive displacement flow meters are suitable for high-temperature or low-temperature applications, as thermal expansion and contraction of the materials could cause rotor jamming or increased leakage. Utility Model Content

[0004] To address the aforementioned problems, this application provides a volumetric flow meter with an ingenious design and simple structure. By incorporating elastic fins on the mating surfaces of the components, this application ensures sealing between components while reducing the precision requirements for component machining and lowering manufacturing costs. The technical solution adopted in this application is as follows:

[0005] A volumetric flow meter includes a housing and two meshing rotors, wherein the housing contains a rotor housing chamber in which the two rotors are housed;

[0006] Elastic fins are provided on the circumferential inner wall of the rotor housing chamber, and the fins are evenly distributed along the inner wall of the rotor housing chamber. The fins slide in contact with the rotor when the rotor rotates; or, elastic fins are evenly distributed on the rotor tooth valleys of the rotor, and the fins on the rotor tooth valleys slide in contact with the rotor tooth tips of another rotor when the rotor in which it is located rotates; or, elastic fins are evenly distributed on the rotor tooth tips of the rotor, and the fins on the rotor tooth tips slide in contact with the rotor tooth valleys of another rotor when the rotor in which it is located rotates.

[0007] By incorporating elastic fins on the mating surfaces of components in a volumetric flow meter, the fins undergo slight elastic deformation upon sliding contact with adjacent components. This elasticity allows for smooth relative sliding between the fins and adjacent components while preventing leakage, ensuring a tight seal between components. Furthermore, the elastic fins reduce the precision requirements for component machining, lowering manufacturing costs. When machining errors occur or gaps between components are excessive, the fins can fill these gaps, and multiple fins form a labyrinth seal along the sealing path. Another important point is that the elastic deformation of the fins can compensate for gap changes caused by thermal expansion and contraction.

[0008] In some embodiments, the fins are made of fluoroplastics or high-temperature alloys. When the fins are made of fluoroplastics, they are suitable for use with highly corrosive fluids; when the fins are made of high-temperature alloys, they are suitable for operating conditions of 200-300°C.

[0009] In some embodiments, the thickness of the fin is 0.1-0.5 mm, and the deformation range of the free end of the fin is 0.05-0.2 mm. This ensures that there is a small sliding resistance between the fin and the adjacent component, while also ensuring that the fin is in close contact with the adjacent component and that the fin does not undergo permanent deformation.

[0010] In some embodiments, when the fins are provided on the inner wall of the rotor housing, the free ends of the fins are inclined in the direction of rotation of the rotor relative to the rotor in which they slide. In other words, the free ends of the fins are inclined toward the front of the rotor in the direction of rotation. This reduces the resistance of each fin sliding relative to the rotor and reduces the pressure loss generated by the fluid or gas passing through the volumetric flow meter.

[0011] In some embodiments, when the fins are arranged in the rotor tooth valley of the rotor, the free ends of the fins are inclined in the direction of rotation of the other rotor relative to which they slide. In other words, the free ends of the fins are inclined toward the front of the direction of rotation of the other rotor. This reduces the resistance of each fin sliding relative to the other rotor and can reduce the pressure loss generated by the fluid or gas passing through the volumetric flow meter.

[0012] In some embodiments, when the fins are provided on the rotor teeth of the rotor, the free ends of the fins are inclined against the rotation direction of the rotor in which they are located. In other words, the free ends of the fins are inclined toward the rear side of the rotation direction of the rotor in which they are located. This can reduce the resistance of each fin sliding relative to another rotor and the resistance of sliding relative to the inner wall of the rotor housing chamber, thereby reducing the pressure loss generated by the fluid or gas passing through the volumetric flow meter.

[0013] The volumetric flow meter provided in this application has at least one of the following beneficial effects:

[0014] 1. This application provides a volumetric flow meter that incorporates elastic fins on the mating surfaces of its components. These fins undergo slight elastic deformation upon sliding contact with adjacent components. This elasticity allows for smooth relative sliding between the fins and adjacent components while preventing leakage and ensuring a tight seal between the components. Furthermore, the elastic fins reduce the precision requirements for component machining, lowering manufacturing costs. When machining errors occur or gaps between components are excessive, the fins can fill these gaps, and multiple fins form a labyrinth seal along the sealing path. It is also important to note that the elastic deformation of the fins can compensate for gap changes caused by thermal expansion and contraction.

[0015] 2. The volumetric flow meter provided in this application, when the fins are made of fluoroplastic, is suitable for highly corrosive fluids; when the fins are made of high-temperature alloy, they are suitable for operating conditions of 200-300℃.

[0016] 3. The volumetric flow meter provided in this application sets the thickness of the fins to 0.1-0.5mm and the deformation of the free end of the fins to 0.05-0.2mm. This ensures that there is a small sliding resistance between the fins and adjacent components, while also ensuring that the fins are in close contact with the adjacent components and that the fins do not undergo permanent deformation.

[0017] 4. The present application provides a volumetric flow meter in which fins are provided on the inner wall of the rotor housing chamber. The free end of the fin is inclined in the direction of rotor rotation relative to the rotor that is in sliding contact with it. In other words, the free end of the fin is inclined towards the front side of the rotor rotation direction. This can reduce the resistance of each fin to sliding relative to the rotor and reduce the pressure loss generated when the fluid or gas passes through the volumetric flow meter.

[0018] 5. The present application provides a volumetric flow meter in which, when fins are provided in the rotor tooth valley of the rotor, the free end of the fin is inclined in the direction of rotation of the other rotor relative to the other rotor that is in sliding contact with it. In other words, the free end of the fin is inclined towards the front side of the rotation direction of the other rotor. This can reduce the resistance of each fin sliding relative to the other rotor and reduce the pressure loss generated when the fluid or gas passes through the volumetric flow meter.

[0019] 6. The present application provides a volumetric flow meter in which, when fins are provided on the rotor teeth, the free ends of the fins are inclined against the rotation direction of the rotor. In other words, the free ends of the fins are inclined toward the rear side of the rotation direction of the rotor. This can reduce the resistance of each fin sliding relative to another rotor and the resistance of sliding relative to the inner wall of the rotor housing, thereby reducing the pressure loss generated when the fluid or gas passes through the volumetric flow meter. Attached Figure Description

[0020] The preferred embodiments will be described below in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of a volumetric flow meter:

[0021] Figure 1 This is a schematic diagram of the structure of an embodiment of the volumetric flow meter of this application;

[0022] Figure 2 This is a schematic diagram of another embodiment of the volumetric flow meter of this application.

[0023] Explanation of icon numbers:

[0024] Rotor housing 1, rotor 2, fins 3. Detailed Implementation

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0026] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0027] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] refer to Figure 1 , Figure 2 This application provides a volumetric flow meter, including a housing and two meshing rotors 2. The housing contains a rotor receiving chamber 1, in which the two rotors 2 are housed. Elastic fins 3 are provided on the inner wall of the rotor receiving chamber 1, which is parallel to the axis of the rotors 2. In other words, elastic fins 3 are provided on the circumferential inner wall of the rotor receiving chamber 2. The fins 3 are evenly distributed along the inner wall of the rotor receiving chamber 1, and the fins 3 slide in contact with the rotors 2 when the rotors 2 rotate. Alternatively, elastic fins 3 are evenly distributed on the rotor tooth valleys of the rotors 2, and the fins 3 on the rotor tooth valleys slide in contact with the rotor tooth tips of the other rotor 2 when the rotor 2 in which they are located rotates. Alternatively, elastic fins 3 are evenly distributed on the rotor tooth tips of the rotors 2, and the fins 3 on the rotor tooth tips slide in contact with the rotor tooth valleys of the other rotor 2 when the rotor 2 in which they are located rotates.

[0031] Specifically, the volumetric flow meter claimed in this application can be an elliptical gear flow meter, a Roots flow meter, or a dual rotor flow meter. The structure of the volumetric flow meter claimed in this application is no different from existing volumetric flow meters except for the fins 3. It is understood that when the volumetric flow meter is an elliptical gear flow meter, rotor 2 refers to the elliptical gear, rotor tooth valley refers to the tooth valley of the elliptical gear, and rotor tooth tip refers to the tooth tip of the elliptical gear; while when the rotary volumetric pump is a dual rotor flow meter, rotor 2 refers to the standard spherical gear, rotor tooth valley refers to the tooth valley of the standard spherical gear, and rotor tooth tip refers to the tooth tip of the standard spherical gear; when the volumetric flow meter is a Roots flow meter, rotor 2 refers to the spherical wheel, rotor tooth valley refers to the recessed part of the spherical wheel, and rotor tooth tip refers to the protruding part of the spherical wheel.

[0032] In this embodiment, the rotor housing 1 is formed by the enclosure of the volumetric flow meter. The fins 3 can be integrally formed with the component containing the fins (shell or rotor 2), or they can be fixed by welding or bonding. Specifically, the fins 3 can be made of stainless steel, oil-resistant / corrosion-resistant engineering plastics, etc. When the volumetric flow meter measures highly corrosive fluids, fluoroplastics are preferred for the fins 3; when the volumetric flow meter operates at high temperatures, such as 200-300°C, high-temperature alloys are preferred for the fins 3. It should be noted that the thickness of the fins 3 is preferably 0.1-0.5 mm, and the deformation range of the free end of the fins 3 is preferably 0.05-0.2 mm. This ensures low sliding resistance between the fins 3 and adjacent components while maintaining tight contact and preventing permanent deformation of the fins 3.

[0033] Understandably, by incorporating elastic fins 3 on the mating surfaces of components in a volumetric flow meter, the fins 3 undergo slight elastic deformation upon sliding contact with adjacent components. This elasticity allows for smooth relative sliding between the fins 3 and adjacent components while preventing leakage, ensuring a tight seal between components. Furthermore, the elastic fins 3 reduce the required machining precision of the components, allowing a reduction from IT6 to IT8, thus lowering manufacturing costs. When machining errors occur or gaps between components are excessive, the fins 3 can fill these gaps. The elastic deformation of the fins 3 absorbs machining errors, reducing the jamming rate to zero and extending the continuous operating life of the equipment. Simultaneously, multiple fins 3 form a labyrinth seal along the sealing path, further preventing fluid leakage, making it particularly suitable for high-pressure fluid measurement, with a 50% improvement in sealing reliability compared to traditional structures. Another point to note is that the elastic deformation of the fins 3 can offset gap changes caused by thermal expansion and contraction, making this volumetric flow meter suitable for high-temperature or low-temperature applications.

[0034] refer to Figure 1 Taking the rotary flow meter as an example, when fins 3 are installed on the inner wall of the rotor housing chamber 1, the free end of the fin 3 is inclined in the direction of rotation of the rotor 2 relative to the rotor 2 that it slides in contact with. In other words, the free end of the fin 3 is inclined towards the front side of the rotor 2 in the direction of rotation. This can reduce the resistance of each fin 3 sliding relative to the rotor 2 and reduce the pressure loss generated when the fluid or gas passes through the volumetric flow meter.

[0035] refer to Figure 2 Taking the rotary flow meter as an example, when fins are installed in the rotor tooth valley of rotor 2, the free end of fin 3 is inclined in the direction of rotation of the other rotor 2 relative to the other rotor 2 that it slides in contact with. In other words, the free end of fin 3 is inclined towards the front side of the rotation direction of the other rotor 2. This can reduce the resistance of each fin sliding relative to the other rotor 2 and reduce the pressure loss generated when the fluid or gas passes through the volumetric flow meter.

[0036] In one embodiment, when fins are provided on the rotor teeth of the rotor, the free ends of the fins are tilted against the rotation direction of the rotor in which they are located. In other words, the free ends of the fins are tilted toward the rear side of the rotation direction of the rotor in which they are located. This can reduce the resistance of each fin sliding relative to another rotor and the resistance of sliding relative to the inner wall of the rotor housing, thereby reducing the pressure loss generated by the fluid or gas passing through the volumetric flow meter.

[0037] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A volumetric flow meter, characterized in that, It includes a housing and two meshing rotors, wherein the housing contains a rotor housing chamber in which the two rotors are housed; Elastic fins are provided on the circumferential inner wall of the rotor housing chamber. The fins are evenly distributed along the inner wall of the rotor housing chamber and slide in contact with the rotor when the rotor rotates. Alternatively, the rotor tooth valley of the rotor is provided with uniformly distributed elastic fins, and the fins on the rotor tooth valley slide in contact with the rotor tooth tip of another rotor when the rotor in which it is located rotates. Alternatively, the rotor teeth of the rotor are provided with uniformly distributed elastic fins, and the fins on the rotor teeth slide into contact with the rotor teeth of the other rotor as the rotor rotates.

2. The volumetric flow meter according to claim 1, characterized in that, The fins are made of fluoroplastics or high-temperature alloys.

3. A volumetric flow meter according to claim 1, characterized in that, The thickness of the fin is 0.1-0.5 mm, and the deformation range of the free end of the fin is 0.05-0.2 mm.

4. A volumetric flow meter according to any one of claims 1-3, characterized in that, When the fins are arranged on the inner wall of the rotor housing, the free ends of the fins are inclined in the direction of rotation of the rotor relative to the rotor in which they slide.

5. A volumetric flow meter according to any one of claims 1-3, characterized in that, When the fins are arranged in the rotor tooth valley of the rotor, the free end of the fins is inclined in the direction of rotation of the other rotor relative to the other rotor in which they slide.

6. A volumetric flow meter according to any one of claims 1-3, characterized in that, When the fins are arranged on the rotor teeth of the rotor, the free ends of the fins are tilted against the rotation direction of the rotor in which they are located.

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