High-precision double-screw flowmeter

Abstract

The utility model discloses a high-precision double-screw flowmeter which comprises a metering shell, a first screw rotor, a second screw rotor, a front bearing seat, a rear bearing seat, a front end cover and a rear end cover, and a rotary encoder which is connected with the second screw rotor and used for measuring the rotating speed of the second screw rotor is arranged on the rear end cover. The rotary encoder is positioned on the outer side of the metering cavity; according to the high-precision double-screw flow meter, the rotary encoder is directly connected with the second screw rotor, the flow is measured by measuring the rotating speed of the second screw rotor, the rotary encoder is located on the outer side of the metering cavity, and no matter what type of fluid is measured, the flow can be accurately measured. Therefore, the detection of the rotation speed of the connection of the second screw rotor by the rotary encoder is not affected, and the measurement precision can be improved.

Description

Technical Field

[0001] The utility model relates to a high-precision twin-screw flowmeter. Background Art

[0002] The Chinese invention patent application with the patent application number of "2020115272254" discloses a twin-screw rotor flowmeter, which comprises a flowmeter housing. A front flange end cover is installed at one end of the flowmeter housing, and a rear flange end cover is installed at the other side. A liquid inlet penetrates through the front flange end cover, and a liquid outlet penetrates through the rear flange end cover. A main screw rotor and a slave screw rotor are installed in the flowmeter housing. A sensor assembly is installed at the middle position of the side wall of the flowmeter housing. A Hall sensor installed in the flow space detects the side of the screw, thereby generating a frequency signal proportional to the flow rate. Each pulse corresponds to a specific measured value. Since the volume of the fluid passing through per revolution of the rotor is fixed, the flow rate of the fluid passing through the flowmeter can be obtained by converting the captured revolution signal into flow rate. In this way, the sensor assembly needs to be installed in the flowmeter housing, that is to say, the probe of the sensor will be in contact with the measured medium. When measuring the flow rate of highly viscous materials (paste) such as glass glue, such highly viscous materials will fill around the probe of the sensor, which will reduce the measurement accuracy.

[0003] The present utility model is studied and proposed in view of the deficiencies of the prior art. Summary of the Utility Model

[0004] Regarding the technical problem of inaccurate measurement when using an existing twin-screw rotor flowmeter to measure the flow rate of highly viscous materials such as glass glue in the above-mentioned existing technology. The technical solution adopted by the present utility model to solve its technical problem is: a high-precision twin-screw flowmeter, comprising: a metering housing, a first screw rotor, a second screw rotor, a front bearing seat, a rear bearing seat, a front end cover, and a rear end cover. The front bearing seat is connected to one end of the metering housing, and the rear bearing seat is connected to the other end of the metering housing. A metering chamber is provided between the front bearing seat, the rear bearing seat, and the metering housing. The screw tooth surfaces of the first screw rotor and the second screw rotor are meshed with each other and are located in the metering chamber. An inlet communicating with the metering chamber is provided on the front bearing seat, and an outlet communicating with the metering chamber is provided on the rear bearing seat. A first bearing for supporting the first screw rotor is provided on the front bearing seat, and a second bearing for supporting the second screw rotor is provided on the front bearing seat. A third bearing and a fourth bearing for supporting the first screw rotor are provided on the rear bearing seat, and a fifth bearing and a sixth bearing for supporting the second screw rotor are provided on the rear bearing seat. The front end cover is connected to the front bearing seat, and the rear end cover is connected to the rear bearing seat. A rotary encoder for measuring the rotational speed of the second screw rotor is provided on the rear end cover and is connected to the second screw rotor. The rotary encoder is located outside the metering chamber.

[0005] For a high-precision twin-screw flowmeter as described above, the third bearing is a thrust bearing or a tapered roller bearing, and the fifth bearing is a thrust bearing or a tapered roller bearing.

[0006] For a high-precision twin-screw flowmeter as described above, the first bearing is a deep groove ball bearing, the second bearing is a deep groove ball bearing, the fourth bearing is a deep groove ball bearing, and the sixth bearing is a deep groove ball bearing.

[0007] For a high-precision twin-screw flowmeter as described above, a feed chamber communicating with the inlet is provided between the front end cover and the front bearing seat.

[0008] For a high-precision twin-screw flowmeter as described above, a discharge chamber communicating with the outlet is provided between the rear end cover and the rear bearing seat.

[0009] For a high-precision twin-screw flowmeter as described above, a discharge joint communicating with the discharge chamber is connected to the rear end cover, and a connecting flange is provided at the end of the discharge joint.

[0010] A high-precision double-screw flowmeter as described above, a sealing assembly is provided between the rear end cover and the second screw rotor. The sealing assembly includes: a sealing seat, a first oil seal, a second oil seal, an O-ring, and a circlip. An installation inner hole is provided in the sealing seat. The installation inner hole is provided with an inwardly protruding annular shoulder. The first oil seal is located inside the annular shoulder, and the second oil seal is located outside the annular shoulder. An annular groove for installing the circlip is provided in the installation inner hole. The circlip is connected in the annular groove to lock the second oil seal in the installation inner hole. The O-ring is connected to the outer ring of the sealing seat.

[0011] The beneficial effects of the present utility model are as follows:

[0012] 1. The high-precision double-screw flowmeter of the present utility model directly connects a rotary encoder to the second screw rotor, and measures the flow rate by measuring the rotation speed of the second screw rotor. The rotary encoder is located outside the metering chamber. No matter what type of fluid is measured, it will not affect the detection of the rotation speed of the second screw rotor connected by the rotary encoder, and the measurement accuracy can be improved.

[0013] 2. During measurement, the first screw rotor and the second screw rotor will bear axial forces. After using for a period of time, it is easy to cause excessive wear and reduce the measurement accuracy. With the above design, the axial friction between the first screw rotor and the second screw rotor can be reduced, and the measurement accuracy and service life can be improved.

[0014] 3. A feed chamber communicating with the inlet is provided between the front end cover and the front bearing seat. The fluid to be measured first enters the feed chamber and then enters the metering chamber for measurement, which can reduce the pressure fluctuation and improve the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a full-sectional schematic diagram of the present utility model;

[0016] Figure 2 is Figure 1 an enlarged view of part A marked in

[0017] Figure 3 is one of the exploded schematic diagrams of the present utility model with some parts hidden;

[0018] Figure 4 is another exploded schematic diagram of the present utility model with some parts hidden. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following will describe in detail the embodiments of the present utility model with reference to the drawings.

[0020] As Figures 1 to 4As shown in the figure, a high-precision twin-screw flowmeter includes: a metering housing 1, a first screw rotor 2, a second screw rotor 3, a front bearing housing 4, a rear bearing housing 5, a front end cover 6, and a rear end cover 7. The front bearing housing 4 is connected to one end of the metering housing 1, and the rear bearing housing 5 is connected to the other end of the metering housing 1. A metering chamber 101 is provided between the front bearing housing 4, the rear bearing housing 5, and the metering housing 1. The screw tooth surfaces of the first screw rotor 2 and the second screw rotor 3 mesh with each other and are located in the metering chamber 101. An inlet 1011 communicating with the metering chamber 101 is provided on the front bearing housing 4, and an outlet 1012 communicating with the metering chamber 101 is provided on the rear bearing housing 5. A first bearing 81 for supporting the first screw rotor 2 is provided on the front bearing housing 4, and a second bearing 82 for supporting the second screw rotor 3 is provided on the front bearing housing 4. A third bearing 83 and a fourth bearing 84 for supporting the first screw rotor 2 are provided on the rear bearing housing 5, and a fifth bearing 85 and a sixth bearing 86 for supporting the second screw rotor 3 are provided on the rear bearing housing 5. The front end cover 6 is connected to the front bearing housing 4, and the rear end cover 7 is connected to the rear bearing housing 5. A rotary encoder 9 for measuring the rotational speed of the second screw rotor 3 is provided on the rear end cover 7 and is connected to the second screw rotor 3. The rotary encoder 9 is located outside the metering chamber 101. The high-precision twin-screw flowmeter of the present invention directly connects the rotary encoder to the second screw rotor and measures the flow rate by measuring the rotational speed of the second screw rotor. The rotary encoder is located outside the metering chamber, and no matter what type of fluid is measured, it will not affect the detection of the rotational speed of the second screw rotor by the rotary encoder, which can improve the measurement accuracy.

[0021] In this embodiment, the third bearing 83 is a thrust bearing or a tapered roller bearing, and the fifth bearing 85 is a thrust bearing or a tapered roller bearing. During measurement, the first screw rotor 2 and the second screw rotor 3 will bear axial forces, and excessive wear is likely to occur after a period of use, reducing the measurement accuracy. With the above design, the axial friction between the first screw rotor 2 and the second screw rotor 3 can be reduced, improving the measurement accuracy and service life.

[0022] In this embodiment, the first bearing 81 is a deep groove ball bearing, the second bearing 82 is a deep groove ball bearing, the fourth bearing 84 is a deep groove ball bearing, and the sixth bearing 86 is a deep groove ball bearing. This can reduce friction and keep the first screw rotor 2 and the second screw rotor 3 running smoothly when rotating.

[0023] In this embodiment, a feed cavity 102 communicating with the inlet 1011 is provided between the front end cover 6 and the front bearing housing 4. The fluid to be measured first enters the feed cavity 102 and then enters the metering cavity for measurement, which can reduce the pressure fluctuation and improve the measurement accuracy.

[0024] In this embodiment, a discharge cavity 103 communicating with the outlet 1012 is provided between the rear end cover 7 and the rear bearing housing 5.

[0025] In this embodiment, a discharge joint 71 communicating with the discharge cavity 103 is connected to the rear end cover 7. A connecting flange 72 is provided at the end of the discharge joint 71, which is convenient for connecting to the conveying pipeline.

[0026] In this embodiment, a sealing assembly 31 is provided between the rear end cover 7 and the second screw rotor 3. The sealing assembly 31 includes: a sealing seat 311, a first oil seal 312, a second oil seal 313, an O-ring 315 and a circlip 316. An installation inner hole is provided in the sealing seat 311. An annular shoulder 3112 protruding inwards is provided in the installation inner hole. The first oil seal 312 is located inside the annular shoulder 3112, and the second oil seal 313 is located outside the annular shoulder 3112. An annular groove 3113 for installing the circlip 316 is provided in the installation inner hole. The circlip 316 is connected in the annular groove 3113 to lock the second oil seal 313 in the installation inner hole. The O-ring 315 is connected to the outer ring of the sealing seat 311. The above design can improve the sealing performance between the rear end cover 7 and the second screw rotor 3.

[0027] The above only further illustrates the technical content of the present invention with embodiments to make it easier for readers to understand, but it does not mean that the implementation modes of the present invention are limited to this. Any technical extension or re-creation based on the present invention is protected by the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A high-precision twin-screw flowmeter, characterized in that: include: A metering housing (1), a first screw rotor (2), a second screw rotor (3), a front bearing seat (4), a rear bearing seat (5), a front end cover (6) and a rear end cover (7), wherein the front bearing seat (4) is connected to one end of the metering housing (1), and the rear bearing seat (5) is connected to the other end of the metering housing (1); a metering cavity (101) is provided between the front bearing seat (4), the rear bearing seat (5) and the metering housing (1); a screw tooth surface of the first screw rotor (2) and a screw tooth surface of the second screw rotor (3) are meshed with each other and are located in the metering cavity (101); an inlet (1011) communicating with the metering cavity (101) is provided on the front bearing seat (4), and an outlet (1012) communicating with the metering cavity (101) is provided on the rear bearing seat (5); and the front bearing seat ( 4) is provided with a first bearing (81) for supporting the first screw rotor (2), the front bearing seat (4) is provided with a second bearing (82) for supporting the second screw rotor (3), the rear bearing seat (5) is provided with a third bearing (83) and a fourth bearing (84) for supporting the first screw rotor (2), and the rear bearing seat (5) is provided with a fifth bearing (85) and a sixth bearing (86) for supporting the second screw rotor (3); the front end cover (6) is connected to the front bearing seat (4), the rear end cover (7) is connected to the rear bearing seat (5), and the rear end cover (7) is provided with a rotary encoder (9) connected to the second screw rotor (3) for measuring the rotation speed of the second screw rotor (3), and the rotary encoder (9) is located outside the metering cavity (101).

2. A high-precision twin-screw flowmeter according to claim 1, characterized in that: The third bearing (83) is a thrust bearing or a tapered roller bearing, and the fifth bearing (85) is a thrust bearing or a tapered roller bearing.

3. A high-precision twin-screw flowmeter according to claim 1 or 2, characterized in that: The first bearing (81) is a deep groove ball bearing, the second bearing (82) is a deep groove ball bearing, the fourth bearing (84) is a deep groove ball bearing, and the sixth bearing (86) is a deep groove ball bearing.

4. A high-precision twin-screw flowmeter according to claim 1, characterized in that: A feed cavity (102) communicating with the inlet (1011) is provided between the front end cover (6) and the front bearing seat (4).

5. A high-precision twin-screw flowmeter according to claim 1 or 4, characterized in that: A discharge cavity (103) communicating with the outlet (1012) is provided between the rear end cover (7) and the rear bearing seat (5).

6. A high-precision twin-screw flowmeter according to claim 1, characterized in that: The rear end cover (7) is connected to a discharge joint (71) communicating with the discharge chamber (103), and a connecting flange (72) is provided at the end of the discharge joint (71).

7. A high-precision twin-screw flowmeter according to claim 1, characterized in that: A sealing assembly (31) is provided between the rear end cover (7) and the second screw rotor (3), the sealing assembly (31) comprising: a sealing seat (311), a first oil seal (312), a second oil seal (313), an O-type sealing ring (315) and a retaining spring (316); a mounting inner hole is provided in the sealing seat (311), the mounting inner hole is provided with an annular shoulder (3112) protruding inwardly, the first oil seal (312) is located on the inner side of the annular shoulder (3112), the second oil seal (313) is located on the outer side of the annular shoulder (3112), an annular groove (3113) for mounting the retaining spring (316) is provided in the mounting inner hole, the retaining spring (316) is connected to the annular groove (3113) for locking the second oil seal (313) in the mounting inner hole, and the O-type sealing ring (315) is connected to the outer ring of the sealing seat (311).

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