JPH0323532Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement in the bearing structure of a rotor in a positive displacement flowmeter.

2. Description of the Related Art Positive displacement flowmeters such as oval gear type flowmeters are capable of measuring the flow rate of fluid with high precision, and are therefore widely used in many fields of industry including trading.

Oval gear flowmeters are well known, as shown in one embodiment in FIG. That is, 1 is a flow meter main body which forms a metering chamber 20, and a hole 1-1 for inserting and fixing one end of the rotor shafts 4, 5 is bored in the bottom of the metering chamber 20, and an inlet is provided. , an outlet (none of which is shown). 2 and 3 are a pair of non-circular gear rotors that mesh and rotate with each other. Each of the non-circular gear rotors 3 has a first bearing 8
Holes 2-1 and 3-1 are provided for fitting. The first bearing 8 has a cylindrical shape, for example, and fits into a hole provided in the rotor shafts 2 and 3.
The rotor shaft 4 is slidably fitted into the rotor shaft 4, and a partition wall 19 is formed in the rotor shaft 4 by, for example, forming a recessed portion 18 therein. 6 is the pair of non-circular gear rotors 2 and 3 in the measurement chamber of the flow meter main body.
It is an end face plate for accommodating the rotor and rotatably supporting the rotor, and is provided with a hole 6-1 through which the other ends of the rotor shafts 4 and 5 are inserted and fixed. 7
is an outer cover, which is fixed to the flow meter main body 1 using fastening members 22 such as bolts. As shown in FIG. 5, 9 is a second bearing mounted with a minute gap h maintained between the end surfaces of the non-circular gear rotors 2 and 3 and the wall surface of the measuring chamber. Reference numeral 11 is, for example, a ring-shaped main drive magnet, which is fitted into the rotor 2 and slidably inserted into the rotor shaft 4. Reference numeral 10 denotes a buffer material inserted between the first bearing 8 and the main drive magnet 11. Reference numeral 12 denotes a transmission shaft, which is rotatably supported in a recessed portion 18 by a ball bearing 14 or the like. Transmission shaft 1
A driven magnet 13 is fixed to one end of the magnet 2 at a position facing the main magnet 11, and the other end is connected to a counter (not shown). The rotation of the rotor is transmitted to the counter by the magnetic coupling between the driving magnet 11 and the driven magnet 13. 16 is Patsukin. 17 is Patsukin.

Problems to be Solved by the Present Invention The oval gear type flowmeter constructed as described above needs to maintain measurement accuracy, so its bearings and sliding parts, such as the rotor, rotor shaft, bearings, or measuring chamber, are It is manufactured so that the rotational friction between the rotors is as small as possible. In other words, as shown in Figure 5, there are minute gaps formed between these rotating parts, and if a fluid with particularly poor lubricity or a special chemical liquid that tends to polymerize if it stagnates is supplied there. The rotational friction may become large, which is not preferable for flow rate measurement.

The present invention aims to solve this drawback, and attempts to smoothly rotate between rotating parts without impairing measurement accuracy.

Means for Solving the Problems In view of the above problems, in a non-circular gear type positive displacement flowmeter such as an oval gear type flowmeter, a first groove is provided in the axial direction in the first bearing, and the first groove is provided in the first bearing in the axial direction. A second groove is provided in the second bearing that communicates with the groove of the rotor, and a second groove is provided in each of the pair of rotors that extends from the shaft center toward the outer diameter and does not communicate with each other and that communicates with the first groove and the second groove. By drilling a hole that communicates with the groove, when a pair of non-circular gears mesh and rotate through the communication path, a pump action can be performed using the confinement pressure of the fluid to be measured that is generated between the meshing tooth profiles as a pressure source. The fluid is fed under pressure to prevent the fluid from stagnation in the bearings and sliding parts of the flowmeter, ie, the rotor, the rotor shaft, the bearings, or between the metering chamber and the rotor.

1 to 4 show an embodiment of the present invention.

FIG. 1 shows an embodiment of the first bearing 8. 8
-1 is a first groove spirally provided along the inner wall of the cylindrical bearing. Reference numeral 8-2 is a notch formed in the end face of the bearing 8. The first groove 8-1 may be provided linearly along the length of the bearing 8. FIG. 2 shows an embodiment of the second bearing 9.
9-1 is a second groove provided radially in the end face of the ring-shaped second bearing 9. This second groove 9-1
may be provided on both end faces. FIG. 3 shows an example of holes drilled in an oval gear type rotor. 2-
Reference numerals 1 and 3-1 designate small holes drilled from the shaft center toward the outer diameter near the minimum radius position of each of the pair of non-circular rotors that mesh and rotate with each other. Here, it is a matter of course that the small hole 2-1 formed in the circular gear rotor 2 is communicated with the notch 8-2 of the first bearing 8. These small holes 2-1, 3-1
are bored in positions that do not directly communicate with each other's rotors. FIG. 4 shows the main parts of a flowmeter constructed using the first and second bearings having grooves and a rotor having small holes according to the present invention.

Function The function of the present invention having the above structure will be explained. The liquid flowing in from the inflow port 1-2 flows into the measuring chamber 20.
At the same time, between the rotor and the flow meter main body, the first bearing, the second bearing, the groove 8-1 provided in the first bearing, and the groove 9-1 provided in the second bearing. The liquid is circulated through the small holes 2-1, 3-1, etc. and the gaps between them. In particular, the liquid is compressed at the meshing part of the toothed gears of the oval flowmeter, but since the gap between the end faces of the liquid gears is made as small as possible to prevent leakage, a sealing pressure is generated and the small holes 2-1, 3- 1 through a pump action using the confinement pressure as a pressure source. This pumped liquid flows out through the communication path of the groove 8-1 and the groove 9-1 provided in the second bearing as it rotates, and the bending stress on the first bearing 8 due to the confining pressure is is reduced compared to

Therefore, even if the temperature of the liquid rises due to rotational friction when measuring a liquid with poor lubricity, sufficient circulation of the liquid is carried out to the rotating parts, cooling the area around the bearing and ensuring smooth rotation. It is done. In addition, even if the temperature of the chemical liquid increases and polymerization is likely to occur, the liquid sprayed from the small holes 2-1 and 3-1 by the pump action is sufficiently supplied around the bearing, so that the liquid can be smoothly polymerized. A rotation is performed.

Effects of the invention This invention guides the fluid flowing into the measuring chamber through the bearing grooves, small holes, etc. provided in locations that do not affect measurement accuracy, so the fluid does not stagnate, resulting in smooth rotation. . In addition, since the amount of leakage between the rotating parts is an extremely small amount of confinement, it can be ignored compared to the flow rate passing through the flowmeter, and therefore does not affect measurement accuracy. In addition, since the liquid does not stagnate even in chemical liquids that tend to polymerize, the flowmeter exhibits its performance effectively.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the first bearing of the present invention, in which A is a sectional view and B is a view taken in the direction of the arrows in FIG. FIG. 2 shows an embodiment of the second bearing of the present invention, in which A is a sectional view and B is a view taken in the direction of the arrows in FIG. Third
The figure shows one embodiment of the rotor according to the present invention, in which A is a sectional view of the main part and a view taken along the line A-A in the Rohi diagram. FIG. 4 is a sectional view of the main part of the present invention. FIG. 5 is a sectional view of the main parts of the conventional example. FIG. 6 is a sectional view of a conventional positive displacement flowmeter. 2... Non-circular gear rotor, 3... Non-circular gear rotor, 2-1... Small hole, 3-1... Small hole, 8...
First bearing, 8-1...First groove, 8-2...
Notch, 9... second bearing, 9-1... second groove.

Claims (1)

[Claims for Utility Model Registration] (1) A first bearing that pivotally supports a pair of non-circular gear rotors driven in proportion to the flow rate on a rotor shaft;
In the positive displacement flowmeter, the pair of non-circular gear rotors are rotatably supported in the measuring chamber by a second bearing mounted between an end surface of the rotor and a wall surface of the measuring chamber. A first groove communicating in the axial direction is provided in the bearing, a second groove communicating with the first groove is provided in the end face of the second bearing, and a groove is provided in each of the pair of rotors from the axial center. A positive displacement flowmeter, characterized in that holes are bored toward the outer diameter that do not directly communicate with each other but communicate with the first groove and the second groove. (2) The positive displacement flowmeter according to claim (1), wherein the size of the hole is at least 1/2 or less of the reference pitch of the gear of the non-circular gear rotor. (3) The positive displacement flowmeter according to claim 1, wherein the hole is located near the minimum diameter of the non-circular gear rotor. (4) The positive displacement flowmeter according to claim (1), wherein the first groove has a spiral shape.