Gear flowmeter

Abstract

The utility model provides a gear flowmeter which comprises an inner shell, an inner cover, a gear and a sensor for identifying rotation of the gear, the inner cover and the inner shell are buckled to form a closed medium cavity, the gear is arranged in the inner shell, the sensor is arranged on the outer side of the medium cavity, the inner shell is provided with a medium inlet and a medium outlet, and the inner cover is arranged on the inner shell. The gear flowmeter comprises an outer shell and an outer cover, the inner shell is arranged in the outer shell, the inner cover is arranged on the outer cover, the outer shell and the outer cover are connected through a bolt, and holes matched with the medium inlet and the medium outlet respectively are formed in the outer shell. The gear flowmeter has the advantages that due to the adoption of the technical scheme, the gear flowmeter has excellent pressure-bearing performance, can meet the flow measurement requirements of acid and alkali media, is stable in structure and low in cost, and can be conveniently disassembled, assembled and maintained.

Description

Technical Field

[0001] The utility model relates to the technical field of precision instruments, in particular to a gear flow meter. Background Art

[0002] Gear flowmeter is a type of volumetric flowmeter, used for precise continuous or intermittent measurement of the flow rate or instantaneous flow rate of liquid in a pipeline. It is particularly suitable for flow measurement of high viscosity media such as heavy oil, polyvinyl alcohol, resin, etc. The structure of the gear flowmeter is as follows: the flowmeter is provided with a cavity through a housing and an upper cover, the housing and the upper cover are connected by bolts, a pair of mutually meshing gears are provided in the flowmeter cavity as rotors, and the flowmeter cavity is provided with a medium inlet and a medium outlet.

[0003] Its working principle is that the flow of the medium causes the gear to rotate, and the rotation of the gear is scanned by two non-contact sensors (pulse detectors). Each tooth generates a pulse, which ultimately generates a frequency signal proportional to the flow rate, and then the flow value Q is obtained.

[0004] When the medium passes through the flowmeter, it usually carries a certain pressure. The gear flowmeter needs to have a certain pressure bearing capacity. Combined with the precision requirements of the flowmeter, the flowmeter housing and the upper cover need to have certain mechanical processing performance and pressure bearing capacity in terms of material. Therefore, the gear flowmeters on the market are mostly made of stainless steel and aluminum alloy. In addition to measuring the flow of media such as heavy oil, polyvinyl alcohol, and resin, gear flowmeters sometimes need to measure the flow of strong acid and strong alkali media. The corrosion resistance of gear flowmeters made of stainless steel and aluminum alloy cannot meet the above requirements. Technicians in this field try to use corrosion-resistant materials to manufacture flowmeters. Polytetrafluoroethylene is used as a corrosion-resistant material in the manufacture of flowmeters because of its acid, alkali, and various organic solvent resistance. Similarly, flowmeters made of polytetrafluoroethylene also have their defects. Because the material is relatively soft, the pressure bearing performance of the flowmeter is not ideal, and after disassembly, it is usually not possible to reassemble due to deformation or wear of the threaded holes. Utility Model Content

[0005] The utility model aims to provide a gear flowmeter, which uses a hard outer shell and an outer cover to wrap a soft but corrosion-resistant inner shell and an inner cover, so as to meet the pressure resistance and corrosion resistance performance requirements of the gear flowmeter.

[0006] The technical solution of the utility model is:

[0007] A gear flowmeter includes an inner housing, an inner cover, a gear and a sensor for identifying the rotation of the gear. A magnet is arranged on each tooth of the gear, and the sensor scans the magnet to obtain a rotation signal of the gear. The gear is a circular gear or an elliptical gear.

[0008] The inner cover and the inner shell are buckled to form a closed medium cavity, the gear is arranged in the inner shell, the sensor is arranged on the outside of the medium cavity, and the inner shell is provided with a medium inlet and a medium outlet. Specifically, the inner cover, the inner shell and the gear are all made of acid and alkali resistant materials, preferably, the inner cover and the inner shell are made of polytetrafluoroethylene, and the gear is made of polytetrafluoroethylene or other corrosion-resistant materials.

[0009] The gear flowmeter comprises an outer shell and an outer cover, wherein the inner shell is arranged in the outer shell, the inner cover is arranged on the outer cover, the outer shell and the outer cover are connected by bolts, and the outer shell is provided with holes respectively matching with the medium inlet and the medium outlet. The inner cover can be buckled on the inner shell by tightening the bolts between the outer shell and the outer cover.

[0010] The outer shell and outer cover are made of metal materials such as stainless steel or aluminum alloy to meet the pressure-bearing requirements of the gear flowmeter, and its machining performance also ensures the detachable performance of the gear flowmeter. The closed medium cavity formed by the acid-base resistant inner cover and inner shell allows the action of the acid-base medium driving the gear to rotate to be located in the medium cavity, ensuring that the outer shell and outer cover are not corroded, and ultimately achieving the pressure-bearing, detachable, and acid-base resistant performance of the gear flowmeter.

[0011] The outer shell is provided with an inner shell groove, the inner shell is arranged in the inner shell groove, the inner shell and the inner shell groove are interference fit, the outer cover is provided with an inner cover groove, the inner cover is arranged in the inner cover groove, the inner cover and the inner cover groove are interference fit. The inner shell and the inner shell groove fit tightly, and the inner cover and the inner cover groove fit tightly, which provide good support for the relatively soft inner shell and the inner cover, thereby ensuring the pressure bearing capacity of the medium cavity.

[0012] The inner shell and the outer shell are both barrel-shaped structures, the opening end face of the inner shell is flush with the opening end face of the outer shell, the inner cover is a circular plate-shaped structure, the inner cover is flush with the side face of the outer cover where the inner cover groove is located, and the inner shell and the inner cover are sealed by an O-ring. The flush setting improves the integrity of the gear flowmeter after assembly.

[0013] In another optional solution of the utility model, the inner shell and the outer shell are both barrel-shaped structures, the open end face of the inner shell protrudes from the open end face of the outer shell, the inner cover protrudes from the side face of the outer cover where the inner cover groove is located, and a sealing gasket is provided between the inner shell and the inner cover. The protruding structure setting allows a certain gap to be left between the outer shell and the outer cover after the gear flowmeter is assembled, so that the sealing condition of the connection between the inner cover and the inner shell can be discovered in time, and the overall pressure bearing performance of the flowmeter is less affected.

[0014] The holes on the outer shell body that match the medium inlet and the medium outlet are threaded holes.

[0015] The acid and alkali media are connected to the media inlet and media outlet through corrosion-resistant joints. The joints are threadedly connected to the threaded holes on the outer shell. The ends of the joints are against the outer periphery of the media inlet and media outlet and are sealed by sealing rings, thereby realizing convenient connection between the joints and the flowmeter, and the acid and alkali media will not overflow onto the outer shell.

[0016] A gear shaft is arranged in the medium cavity, and the gear is connected to the gear shaft through a bearing. A gear shaft hole is arranged on the bottom wall of the inner shell, and the gear shaft hole is a blind hole.

[0017] Specifically, the gear shaft and the bearing are made of ceramic, and the blind hole is arranged on the basis of the fixed gear shaft to ensure the airtightness of the medium cavity and prevent the medium from overflowing from the medium cavity through the gear shaft. Furthermore, a blind hole is also arranged on the inner cover corresponding to the gear shaft.

[0018] The sensor is arranged on the outer cover. Specifically, a blind hole is arranged on the outer side of the outer cover, and the sensor is arranged in the blind hole.

[0019] The advantages and positive effects of the utility model are as follows: due to the adoption of the above technical solution, the gear flow meter has excellent pressure bearing performance, can meet the flow measurement requirements of acid and alkali media, has a stable structure, low cost, and can be easily disassembled and repaired. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structural principle of the utility model

[0021] Figure 2 It is an explosion diagram of the utility model

[0022] In the figure:

[0023] 1. Outer cover 2. Outer shell 3. Gear

[0024] 4. Inner shell 5. Inner cover 6. Sealing gasket

[0025] 11. Positioning pin 21, positioning hole 22, threaded hole

[0026] 41. Medium inlet 42. Medium outlet DETAILED DESCRIPTION

[0027] like Figure 1 , 2 As shown, the utility model:

[0028] A gear flowmeter comprises an outer shell 2 made of aluminum alloy and an outer cover 1, wherein the outer shell is provided with an inner shell groove, in which an inner shell 4 made of polytetrafluoroethylene is provided, the inner shell 4 and the inner shell groove are interference fit, and an O-ring is provided on the upper end surface of the inner shell 4. An inner cover groove is provided on the lower side of the outer cover 1, and an inner cover 5 made of polytetrafluoroethylene is interference fit in the inner cover groove. A threaded hole and a positioning hole 21 are provided on the outer shell, and a through hole corresponding to the threaded hole and a positioning pin 11 corresponding to the positioning hole are provided on the outer cover. The outer shell 2 and the outer cover 1 are connected by bolts, and after the outer cover 1 is buckled, a closed medium cavity is formed between the inner cover 5 and the inner shell 4.

[0029] The bottom of the inner shell 4 and the inner cover 5 are provided with corresponding gear shaft holes, and the gear shaft made of ceramic material is fixed in the medium cavity through the gear shaft hole. The gear 3 made of ceramic material is rotatably connected to the gear shaft through a ceramic bearing.

[0030] The inner shell is provided with a medium inlet 41 and a medium outlet 42, and the outer shell is provided with a threaded hole 22 at positions corresponding to the medium inlet and the medium outlet. The inner diameter of the threaded hole 22 is larger than the inner diameters of the medium inlet and the medium outlet.

[0031] The acid and alkali media are connected to the media inlet and media outlet through corrosion-resistant joints. The joints are threadedly connected to the threaded holes on the outer shell. The ends of the joints are against the outer periphery of the media inlet and media outlet and are sealed by sealing rings, thereby realizing convenient connection between the joints and the flowmeter, and the acid and alkali media will not overflow onto the outer shell.

[0032] Each tooth of the gear 3 is provided with a magnet. The sensor scans the magnet to obtain the rotation signal of the gear, which is then converted into flow data.

[0033] The outer shell and outer cover made of aluminum alloy ensure the pressure-bearing performance and connection accuracy of the gear flowmeter. The accurate connection ensures the sealing of the medium cavity. The gears, bearings and gear shafts made of ceramic materials and the inner shell and outer cover made of polytetrafluoroethylene ensure the acid and alkali corrosion resistance of the medium cavity.

[0034] The above is a detailed description of an embodiment of the utility model, but the content is only a preferred embodiment of the utility model and cannot be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of application of the utility model should still fall within the scope of the patent coverage of the utility model.

Claims

1. A gear flow meter, comprising an inner housing, an inner cover, a gear and a sensor for identifying the rotation of the gear, wherein the inner cover and the inner housing are buckled to form a closed medium cavity, the gear is arranged in the inner housing, the sensor is arranged outside the medium cavity, and the inner housing is provided with a medium inlet and a medium outlet, characterized in that: The gear flowmeter comprises an outer shell and an outer cover, wherein the inner shell is arranged in the outer shell, the inner cover is arranged on the outer cover, the outer shell and the outer cover are connected by bolts, and the outer shell is provided with holes respectively matching with the medium inlet and the medium outlet.

2. The gear flow meter according to claim 1, characterized in that: The outer shell is provided with an inner shell groove, the inner shell is arranged in the inner shell groove, the inner shell and the inner shell groove are interference fit, the outer cover is provided with an inner cover groove, the inner cover is arranged in the inner cover groove, and the inner cover and the inner cover groove are interference fit.

3. The gear flow meter according to claim 2, characterized in that: The inner shell and the outer shell are both barrel-shaped structures, the opening end surface of the inner shell is flush with the opening end surface of the outer shell, the inner cover is flush with the side surface of the outer cover where the inner cover groove is located, and the inner shell and the inner cover are sealed by an O-ring.

4. The gear flow meter according to claim 2, characterized in that: The inner shell and the outer shell are both barrel-shaped structures, the open end surface of the inner shell protrudes from the open end surface of the outer shell, the inner cover protrudes from the side surface of the outer cover where the inner cover groove is located, and a sealing gasket is provided between the inner shell and the inner cover.

5. The gear flow meter according to claim 1, characterized in that: The holes on the outer shell body that match the medium inlet and the medium outlet are threaded holes.

6. The gear flow meter according to claim 1, characterized in that: A gear shaft is arranged in the medium cavity, and the gear is connected to the gear shaft through a bearing. A gear shaft hole is arranged on the bottom wall of the inner shell, and the gear shaft hole is a blind hole.

7. The gear flow meter according to any one of claims 1 to 5, characterized in that: The sensor is arranged on the outer cover.

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