JP2023007390A - Rotary piston type flowmeter - Google Patents

Abstract

To provide a long-life rotary piston type flowmeter that prevents abrasion powder from being accumulated within a metering chamber and can measure a minute flow rate precisely.SOLUTION: A rotary piston type flowmeter 1 includes: a metering chamber 2 in a closed-end cylindrical shape having an inflow port and a discharge port of liquid; and a rotor 5 capable of rotating the metering chamber 2 freely eccentrically. The metering chamber 2 is formed by forming an annular partition wall 2b at the center of the bottom part, and the annular partition wall 2b includes an eccentric bearing 6 rotatably arranged in the inside. The eccentric bearing 6 includes an eccentric shaft supporting section 6a formed while being extended in an axial direction with predetermined distance from the center of the rotation, and the eccentric shaft supporting section 6a journals a center shaft 5a of the rotor 5, and includes a communication part in which the inner wall communicates with an inner wall 2a of the annular partition wall 2b. Accordingly, the flowmeter has an advantage of easily discharging abrasion powder generated by relative rotation of the center shaft 5a and the eccentric shaft supporting section 6a from the eccentric bearing 6.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a rotary piston flowmeter equipped with an eccentric bearing that rotatably supports an oscillating rotor.

As shown in Patent Document 1, a conventional rotary piston type flowmeter has a substantially bottomed cylindrical measuring chamber having a liquid inlet and a liquid outlet at the top, and a measuring chamber that is eccentrically rotatably arranged in the measuring chamber. a rotor; The metering chamber includes an annular partition formed at the center of the bottom thereof, and a wall plate connecting the annular partition and the inner wall of the metering chamber and partitioning the inlet and the outlet. The rotor is provided with a central shaft serving as the center of rotation thereof and a notch formed so as to be able to be inserted into the partition plate. A portion is fitted into the partition plate. Further, the annular partition wall has a small-diameter outer peripheral wall and a large-diameter inner peripheral wall.

As a result, in the conventional rotary piston type flow meter, the rotor is pressed by the liquid flowing into the measuring chamber from the inlet, so that the rotor rotates eccentrically along the inner wall of the measuring chamber, and the fluid flows from the inlet. They can be delivered sequentially to the ejection port. Therefore, the conventional rotary piston flowmeter can measure the flow rate based on the amount of liquid discharged per eccentric rotation of the rotor. Further, when the rotor rotates eccentrically, the center shaft supported so as to be sandwiched between the outer and inner peripheral walls revolves along the annular partition wall, and the notch portion that engages with the partition plate is a partition member. It slides back and forth along the plate. Therefore, the rotor irregularly rotates eccentrically along the inner wall of the measuring chamber, and is characterized in that the liquid that has flowed into the measuring chamber from the inflow port is sent out sequentially to the discharge port.

As described above, in this conventional rotary piston type flow meter, the central axis of the rotor is sandwiched between the outer and inner peripheral walls of the annular partition wall, and the opposing two points are in line contact and axially supported. Most are not pivoted. As a result, the liquid flowing into the measuring chamber presses the rotor, so that the central axis tends to tilt in a direction in which it does not contact the outer and inner peripheral walls, and the rotor may tilt without maintaining a horizontal posture. This inclination of the rotor increases the rotational resistance of the rotor and changes the clearance between the rotor and the inner wall of the measuring chamber, leading to an increase in the amount of liquid leaking from the measuring chamber. Therefore, the conventional rotary piston type flow meter has a problem that it is difficult to perform accurate flow measurement.

A rotary piston type flow meter that solves this problem is disclosed in Japanese Unexamined Patent Application Publication No. 2002-200322. The conventional rotary piston type flowmeter disclosed in this patent document 2 comprises an eccentric bearing rotatably arranged in an annular partition wall, and this eccentric bearing can support the central axis of the rotor and through holes radially spaced apart from each other.

The conventional rotary piston type flowmeter disclosed in Patent Document 2 having such a configuration has a feature that the rotor is less likely to tilt because of the configuration in which the through hole covers the periphery of the central axis.

Japanese Utility Model Laid-Open No. 52-162162 JP 2018-173365 A

However, in the conventional rotary piston flowmeter disclosed in Patent Document 2, when the rotor rotates irregularly and eccentrically, the central shaft and the through-hole rotate relatively. However, there is a problem in that it is difficult to escape from the through-hole that surrounds the center axis and tends to remain in the gap around the axis between the central axis and the through-hole. If this abrasion powder continues to stay in place without movement for a long period of time without flow rate measurement, it may bind and adhere to rust or the like that occurs with the passage of time. Therefore, if the conventional rotary piston type flowmeter is not used for a long period of time, the central shaft and the through hole, which must rotate relative to each other, are likely to adhere due to abrasion dust, so that the rotor will not rotate smoothly when it is used again. There was also the problem of difficulty.

In addition, when measuring a very small amount of liquid, the conventional rotary piston flowmeter must set the volume of the measuring chamber small to reduce the amount of liquid discharged when the rotor rotates once inside the measuring chamber. Therefore, a rotary piston type flowmeter for very small flow rates must have a small outer diameter of the rotor and an inner diameter of the annular partition. It cannot be set to a small diameter due to strength problems compared to the diameter reduction rate of . For this reason, conventional rotary piston type flowmeters for very small flow rates have a structure that does not include an eccentric bearing as disclosed in Patent Document 1, and the eccentric bearing cannot be arranged. There is also the problem that it is difficult to accurately measure a very small flow rate, which tends to tilt and the pressure of the fluid is weak. Further, the conventional rotary piston type flowmeter, which does not have an eccentric bearing, has a problem that the rotor tends to tilt, and the wear of the rotor and the measuring chamber tends to accelerate, resulting in a short life.

SUMMARY OF THE INVENTION The object of the present invention is to make it difficult for abrasion powder generated by the relative rotation of a rotor and an eccentric bearing to stay in a measuring chamber and to enable accurate flow rate measurement. In a rotary piston type flow meter comprising a bottomed cylindrical measuring chamber and a rotor capable of eccentrically rotating the measuring chamber, the measuring chamber is formed with an annular partition formed in the center of the bottom thereof, and the annular partition is , an eccentric bearing rotatably disposed inside thereof, said eccentric bearing comprising an eccentric shaft support portion formed to extend in the axial direction at a predetermined distance from the center of rotation thereof, said eccentric shaft support portion It is characterized in that it supports the central axis of the rotor, and has a communicating portion whose inner wall communicates with the inner wall of the annular partition. In addition, the communication portion may be configured by a notch groove obtained by cutting the outer circumference of the eccentric bearing in the axial direction, or may include a plurality of communication holes scattered about the outer circumference of the eccentric bearing. Further, it is preferable that the central axis of the rotor is configured to be closer to the annular partition wall than to the outer circumference of the eccentric bearing. Furthermore, it is preferable that the eccentric shaft supporting portion always supports the central axis of the rotor at two or more locations in the circumferential direction, and may pass through the eccentric bearing in the axial direction. The measuring chamber includes a wall plate that partitions the inlet and the outlet, the wall plate connecting the inner wall of the measuring chamber and the annular partition, and the rotor being able to pass through the wall plate. may be provided with a notch.

In the rotary piston type flow meter according to the present invention, since a communication portion communicating with the annular partition is formed on the inner wall of the eccentric shaft support portion that supports the central axis of the rotor, relative rotation between the rotor and the eccentric bearing Generated abrasion powder can be discharged from the circumferential direction of the center shaft. Therefore, the rotary piston type flowmeter according to the present invention has the advantage that it is difficult for the abrasion powder to remain in the measuring chamber, and a small-diameter measuring chamber can be configured to enable measurement of minute flow rates. Further, the rotary piston type flow meter according to the present invention is provided with notched grooves formed by notching the outer circumference of the eccentric bearing in the axial direction and communicating holes scattered around the outer circumference of the eccentric bearing, so that abrasion powder can be removed. There is also the advantage that it is easy to discharge from the eccentric bearing. Furthermore, in the rotary piston type flowmeter according to the present invention, the central shaft housed in the eccentric shaft support is arranged closer than the outer circumference of the eccentric bearing so as to be in contact with the annular partition wall, so the diameter of the eccentric bearing can be reduced. Therefore, there is also the advantage that the rotational resistance of the eccentric bearing can be reduced. In addition, in the rotary piston type flowmeter according to the present invention, the eccentric shaft support is always supported at two or more points in the circumferential direction of the central axis of the rotor, so that the rotational resistance between the relatively rotating central shaft and the eccentric shaft support is reduced. There is also the advantage that it can be reduced and the tilting of the rotor can also be prevented. Furthermore, since the eccentric shaft support extends through the eccentric bearing in the axial direction, there is the advantage that the abrasion powder can be discharged not only in the circumferential direction of the eccentric bearing but also in the axial direction. Further, the rotary piston type flow meter according to the present invention is provided with a wall plate that partitions the liquid inlet and outlet, and the rotor is formed with a notch portion that can be inserted into the wall plate. The rotation speed of is made irregular according to the rotation angle. As a result, the force to be applied to the liquid that has flowed in from the inlet can be applied irregularly according to the rotation angle, so there is also the advantage that the rotor can be rotated smoothly.

1 is a longitudinal sectional view of a rotary piston type flowmeter according to the present invention; FIG. FIG. 3 is an operation explanatory diagram for explaining the rotary piston type flowmeter according to the present invention; (a) is a cross-sectional view taken along the line AA in FIG. 1, and (b) shows a state in which the rotor has been eccentrically rotated counterclockwise by 90 degrees from the state in (a). 2(a) and 2(b); FIG. (a) shows a state in which the rotor has further eccentrically rotated 90 degrees counterclockwise from the state shown in FIG. Shows rotated state. FIG. 3 is a perspective view showing an eccentric bearing mounted on the rotary piston type flowmeter according to the present invention; (a) is a perspective view of an eccentric bearing provided with notched grooves shown in FIGS. 1 to 3, and (b) is a perspective view of an eccentric bearing provided with communication holes.

A rotary piston type flow meter according to the present invention will be described with reference to FIGS. 1 to 4. FIG. A rotary piston type flowmeter 1 according to the present invention comprises a bottomed cylindrical measuring chamber 2 having a liquid inlet 3c and a liquid outlet 3b, and a rotor 5 which is eccentrically rotatable along the inner wall 2a of the measuring chamber 2. and

As shown in FIGS. 1, 2(a), (b), and 3(a), (b), the metering chamber 2 comprises an annular partition wall 2b formed at the center of the bottom, the inlet 3c and and a wall plate 2c that partitions the discharge port 3b. The annular partition 2b has an eccentric bearing 6 rotatably disposed therein, while the wall plate 2c connects the inner wall 2a of the weighing chamber 2 and the annular partition 2b. The annular partition wall 2b is formed to have a smaller diameter than the inner wall 2a of the weighing chamber 2. As shown in FIG. As shown in FIG. 1, the inflow port 3c is connected to a supply pipe 4b through which the liquid supplied from the upstream can pass and is arranged above the measuring chamber 2, while the discharge port 3b is connected to the inflow port. It is connected to a discharge pipe 4a arranged above the measuring chamber so as to be aligned with 3c and through which the liquid discharged from the measuring chamber 2 can pass.

As shown in FIGS. 1, 2(a), (b), and 3(a), (b), the rotor 5 is inserted through a central shaft 5a formed at the center of rotation and the wall plate 2c. and a possible cutout 6b. The rotor 5 is molded integrally with the central shaft 5a and is made of a hard resin material.

As shown in FIGS. 1 and 4(a) and (b), the eccentric bearing 6 is provided with an eccentric shaft support portion 6a eccentrically spaced from the center of rotation by a predetermined distance and extending in the axial direction.

The eccentric shaft support portion 6a is formed so as to penetrate in the axial direction, and is formed so as to rotatably support the central shaft 5a of the rotor 5. As shown in FIG. Further, the eccentric shaft support portion 6a supports the central shaft 5a of the rotor 5 so as to cover the outer circumference thereof, and is guided in the circumferential direction so as to be in surface contact therewith. In addition to this axial support by surface contact, the central shaft 5a is configured to be axially supported by always contacting two or more points, thereby obtaining the effect that the central shaft 5a is less likely to tilt with respect to its axis. be done. Further, the axial dimension of the eccentric shaft support portion 6a is set to be at least twice the diameter of the central shaft 5a of the rotor 5, so that inclination of the central shaft 5a can be suppressed. Further, the eccentric shaft support portion 6a is provided with a communicating portion formed such that its inner wall communicates with the inner wall 2a of the annular partition wall 2b.

The communicating portion may be a substantially U-shaped notch groove 6c formed by axially cutting the outer circumference of the eccentric bearing 6 and the inner wall of the eccentric shaft support portion 6a as shown in FIG. It may be a character shape. The notch groove 6c may have a width smaller than the diameter of the central shaft 5a as shown in FIG. 4(a), or may have a width larger than the diameter of the central shaft 5a. good.

The communication portion may be a communication hole 6d formed by partially communicating the outer circumference of the eccentric bearing 6 and the inner wall of the eccentric shaft support portion 6a as shown in FIG. 4(b). The communicating holes 6d may be arranged so as to be scattered in plural on the outer peripheral surface of the eccentric bearing 6 as shown in FIG. In this way, if only the communication hole 6d is arranged and the notch groove 6c is not arranged, the central axis 5a of the rotor 5 can be axially supported while being covered.

In this way, since the eccentric shaft support portion 6a is provided with the communication portion, abrasion powder generated by contact between the central shaft 5a and the inner diameter of the eccentric shaft support portion 6a can be discharged from the communication portion.

The operation of the rotary piston type flowmeter 1 according to the present invention described above will be described below. In the rotary piston type flow meter 1 according to the present invention, the rotor 5 is pressed by the liquid that has flowed into the measuring chamber 2 through the inlet pipe 4b and the inlet 3c. ), the rotor 5 starts eccentrically rotating counterclockwise along the inner wall 2a of the weighing chamber 2. As shown in FIG. At this time, since the notch 6b of the rotor 5 is engaged with the wall plate 2c, the central shaft 5a is rotated from the 9 o'clock position to the 12 o'clock position with respect to the eccentric bearing 6 by 90 degrees. In addition, the rotor 5 slides upward along the wall plate 2c. In this manner, the rotary piston type flowmeter 1 according to the present invention sequentially draws out the liquid that has flowed into the measurement chamber 2 by the irregular eccentric rotation of the rotor 5 in the counterclockwise direction.

Subsequently, as shown in FIGS. 3(a) and 3(b), the rotor 5 rotates the center shaft 5a with respect to the eccentric bearing 6 to the 3 o'clock position and the 6 o'clock position in order. , slides downward along the wall plate 2c. In this manner, the rotor 5 performs irregular eccentric rotation in the counterclockwise direction in the order of FIGS. 2(a), (b) and FIGS. Outlet 3b sends out to the drain pipe 4a.

The rotary piston type flowmeter 1 according to the present invention stores in advance the discharge amount of the liquid discharged per irregular eccentric rotation of the rotor 5 as a set discharge amount, and counts the number of revolutions of the rotor 5. and store it as the measured number of revolutions. Further, the rotary piston type flowmeter according to the present invention calculates and displays the flow rate of the liquid based on the measured rotation speed and the set discharge amount.

As described above, when the rotor 5 is irregularly eccentrically rotated in the weighing chamber 2, the central shaft 5a and the eccentric shaft support 6a that supports the same rotate relatively. Wear powder may be generated due to contact with the inner wall of 6a, but the rotary piston type flowmeter 1 according to the present invention easily discharges the wear powder from the communicating portion. Therefore, it is possible to rotate the rotor 5 more smoothly than before. Moreover, since the rotor 5 is provided with the eccentric bearing 6 for preventing the inclination of the rotor 5, the inclination of the rotor 5 can be prevented, and the very small flow rate of the liquid can be measured with high accuracy.

2 and 3, the radial dimension of the eccentric shaft support portion 6a of the eccentric bearing 6 is set smaller than the diameter of the central shaft 5a of the rotor 5. The central shaft 5a protrudes radially outward from the outer side surface of the eccentric bearing 6, and is set to be sandwiched and held between the groove wall surface of the notch groove 6c and the annular partition wall 2b. ing. Therefore, the eccentric bearing 6 does not need to support the central shaft 5a from the outside in the radial direction, and is designed to have a smaller diameter than conventional eccentric bearings in which the eccentric shaft supporting portion covers the entire circumference of the central shaft. can. When the diameter of the eccentric bearing 6 is designed to be small in this way, the size of the entire flowmeter including the annular bulkhead 2b enclosing the eccentric bearing 6 and the metering chamber 2 can also be designed to be small. That is, when the eccentric bearing 6 has the structure described above, the rotary piston type flowmeter 1 may be designed as a small flowmeter for measuring minute flow rates. Accurate minute flow measurement becomes possible.

The rotary piston type flowmeter 1 according to the present invention may have both the notch groove 6c and the communication hole 6d, thereby more efficiently discharging abrasion powder. Further, the rotary piston type flow meter 1 according to the present invention can measure the flow rate of water, oil, and various chemical liquids. Make flow rate measurable. Furthermore, the rotary piston type flow meter 1 according to the present invention is configured to calculate the liquid flow rate based on the previously stored set discharge amount and the rotation speed of the rotor 5, but is not limited to this. A configuration may be adopted in which a plurality of gears that rotate with the rotation of the rotor 5 are meshed with each other, and the gears are exchanged according to the type of liquid so that the flow rate display can be adjusted. Also, the inflow direction of the liquid and the eccentric rotation direction of the rotor 5 may be opposite to those in the above embodiment.

DESCRIPTION OF SYMBOLS 1... Rotary piston type flowmeter 2... Measuring chamber 2b... Annular partition 5... Rotor 5a... Center shaft 6... Eccentric bearing 6a... Eccentric shaft support

Claims (7)

A rotary piston type flowmeter comprising a bottomed cylindrical measuring chamber having a liquid inlet and a liquid outlet, and a rotor capable of eccentrically rotating the measuring chamber,
The weighing chamber has an annular partition formed in the center of its bottom,
The annular partition is provided with an eccentric bearing rotatably arranged inside thereof,
The eccentric bearing comprises an eccentric shaft support part formed to extend in the axial direction at a predetermined distance from the center of rotation,
A rotary piston type flowmeter, wherein the eccentric shaft support portion supports the central axis of the rotor, and the inner wall of the eccentric shaft support portion includes a communication portion that communicates with the inner wall of the annular bulkhead. 2. The rotary piston type flowmeter according to claim 1, wherein the communicating portion is a notched groove obtained by notching the outer periphery of the eccentric bearing in the axial direction. 3. The rotary piston type flowmeter according to claim 1, wherein the communication portion is a plurality of communication holes scattered around the outer periphery of the eccentric bearing. 4. The rotary according to any one of claims 1 to 3, wherein the center axis of the rotor is configured to be closer to the annular partition wall than to the outer periphery of the eccentric bearing. Piston type flow meter. 5. The rotary piston type flowmeter according to claim 1, wherein said eccentric shaft supporting portion always supports the central axis of said rotor at two or more points in the circumferential direction. 6. The rotary piston type flowmeter according to claim 1, wherein the eccentric shaft supporting portion axially penetrates the eccentric bearing. The measuring chamber includes a wall plate that partitions the inlet and the outlet,
The wall plate is formed by connecting the inner wall of the weighing chamber and the annular partition,
7. A rotary piston flowmeter according to claim 1, wherein said rotor has a notch through which said wall plate can be inserted.

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