JPH07103794A - Turbine meter - Google Patents

Abstract

PURPOSE:To provide a turbine meter which can measure flow rate from a low flow-rate region and has an improved durability. CONSTITUTION:The title meter is provided with a turbine rotor 8 which is provided at a channel and bearing members 11 and 12 for supporting the turbine rotor 8 so that it can rotate freely and measures the flow rate by detecting the rotation of the magnet 14 attached to the turbine rotor 8 using a magnetic sensor. Then, a spherical body 11 made of carbide alloy is sealed to both edges of a turbine shaft 10 of the turbine rotor 8 and the bearing 12 made of an artificial jewel with a bearing surface for supporting the spherical body 11 as a recessed spherical surface 12a is provided. Since the spherical body sealed to both edges of the turbine shaft is supported by the recessed spherical surface of the bearing, the contact resistance between the shaft and the bearing becomes small, load is infrequently applied to the rotation of the turbine rotor even at a low flow-rate region, and hence the rotor rotates accurately up to a small flow rate in proportion to the flow rate. Also, use of the spherical body made of carbide alloy and the bearing made of artificial jewel formed on the recessed spherical surface prevents wear, thus accurately achieving the measurement of flow rate from a small flow rate over a long period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine meter for measuring a flow rate of a fluid from a minute flow rate with high accuracy.

[0002]

2. Description of the Related Art Generally, in a turbine type flow meter, a turbine rotor having a plurality of blades is arranged in a fluid passage, a bearing for rotatably supporting the turbine rotor is provided, and a magnet attached to the turbine rotor rotates. It is known to detect the flow rate with a magnetic sensor or the like and measure the flow rate based on the rotation speed of the turbine rotor. The bearing portion of this type of flow meter uses a cylindrical plain bearing to support the turbine shaft.

[0003]

With this conventional bearing structure, the sliding resistance of the slide bearing acts as a load on the rotational force of the turbine rotor, which is a major factor of performance degradation. Especially, in the low flow rate region, the rotational force of the turbine rotor due to the fluid is small, so that the sliding bearing cannot rotate in proportion to the flow rate, resulting in a decrease in measurement accuracy and incapability of measurement. Further, when used for general industries, dust and sand enter the bearing portion and wear the turbine shaft and the bearing, which poses a problem of durability performance. The present invention has been made with the object of solving these problems, providing stable flow rate measurement from a low flow rate range, preventing wear due to dust and sand, and providing a turbine meter having a simple and inexpensive structure. It is a thing.

[0004]

To achieve this object, a turbine rotor provided in a fluid passage and a bearing member for rotatably supporting the turbine rotor are provided.
In a flowmeter that measures the flow rate by detecting the rotation of a magnet attached to a turbine rotor with a magnetic sensor, cemented carbide spheres are fixed to both ends of the turbine shaft of the turbine rotor, and the bearing surface that supports this sphere is a concave spherical surface. A turbine meter provided with a bearing for an artificial jewel formed in.

[0005]

With this structure, the inflowing liquid is rectified by the front guide member 5 and hits the impeller 9 inclined in a stable flow state to rotate the turbine rotor 8. The bearing portion of this turbine meter is the turbine shaft 10
Cemented carbide spheres 11 at both ends are supported by bearings 12 and 12 having concave spherical surfaces 12a made of artificial jewels provided at the front and rear, so that they are supported by almost point contact and friction resistance during rotation is small. Moreover, there is no abrasion due to dust, sand, etc. Therefore, rotation proportional to the flow rate of the liquid can be obtained from the low flow rate range, and accurate flow rate measurement can be performed from the low flow rate range for a long period of time.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, reference numeral 1 denotes a tubular meter body, which has a flow passage extending along the axis A. At both ends of the meter body 1, an inflow side connecting member 2 and an outflow side connecting member 3 are provided.
Are assembled with the seal member 4 sandwiched therebetween so that they can be screw-connected to the piping material. In addition, the meter body 1
The front guide member 5 in the form of a shell is provided on the inflow side of the plate
a (FIG. 3) so as to be located at the center of the flow channel, and the rear guide member 6 is provided on the outflow side of the meter body 1 by the plate-shaped rib portion 6a (FIG. 4) at the center of the flow channel. The meter body 1 is fitted so as to be positioned and is held by the pressing ring 7.
It is attached to.

A turbine rotor 8 is arranged between the front guide member 5 and the rear guide member 6, and is rotatably supported by bearings 12 provided on the front guide member 5 and the rear guide member 6. There is. As shown in FIG. 1, the turbine rotor 8 is constituted by fixing an impeller 9 having a plurality of blades inclined at a predetermined angle with respect to an axis A to the turbine shaft 10. At both ends of the turbine shaft 10, a cemented carbide (JIS H
The spheres 11 of 5501 C type No. 2) are fixed so as to protrude substantially from a hemispherical surface. Further, a magnet (permanent magnet) 14 is fixed to a central portion of the turbine shaft 10 in a direction orthogonal to the axis A along with a protective member 13 made of a non-magnetic material so that the turbine shaft 10 and the turbine shaft 10 rotate together. ing. The bearing 12, which supports the turbine shaft 10,
Reference numeral 12 denotes a bearing surface on the rear end axis of the front guide member 5 which is a concave spherical surface 1.
A bearing 12 of precision-finished artificial jewel (artificial sapphire) is fixed to 2a, and a shaft 16 of the rear guide member 6 is provided with an adjustment shaft 15 which can be adjusted forward and backward by a screw.
Is fixed to the rear guide member 6, and the bearing 12 of an artificial jewel (artificial sapphire) whose bearing surface is precisely finished into a concave spherical surface 12a is fixed to the front end axis of the adjusting shaft 15. These bearings 12 and 12 are formed on a concave spherical surface 12a having a radius slightly larger than the radius of the sphere 11, and between the front and rear bearings 12 and 12, the axial direction required for the turbine shaft 10 to rotate. It is assembled with a minute gap.

On the other hand, a mounting hole for the pressure resistant cover 17 is provided directly above the magnet 14, and the cylindrical pressure resistant cover 17 with a bottom is fixed to the meter body 1 with the seal ring 18 interposed therebetween. There is. A magnetic sensor (magnetoresistive element type) 19 is incorporated in the bottom of the pressure-resistant cover 17 so as to detect the rotation of the magnet 14 in a non-contact state and without coming into contact with liquid.

This turbine meter is mounted in the pipe, and the liquid to be measured is made to flow in the direction of the arrow in FIG. The liquid flowing through the inflow-side connecting member 2 flows into the front guide member 5
Impeller 9 which is rectified by and is inclined in a stable flow state
And acts to rotate the turbine rotor 8. Since the bearing portion of this turbine meter is supported by the bearings 12 and 12 having the concave spherical surfaces 12a of artificial jewels provided with the cemented carbide spheres 11 and 11 at both ends of the turbine shaft 10 in front and back, the bearing portion is supported by almost point contact. Therefore, the frictional resistance during rotation is extremely small, and therefore accurate rotation of the turbine rotor 8 can be obtained in proportion to the flow rate of the liquid, and since it is made of a material with high hardness, it is worn by dust or sand in the fluid. Is extremely small. The rotation of the turbine rotor 8 is detected by a magnetic sensor 19 provided above the magnet 14, and the flow rate can be known by inputting this detection signal to a flow rate converter (not shown).
Then, the liquid that has passed through the turbine rotor 8 passes through the rear guide member 6 and flows out from the outflow side connection member 3.

Next, FIG. 5 shows the measurement test results of the turbine meter according to this embodiment and a conventional slide bearing type turbine meter. As shown in this instrumental error curve (accuracy curve), first, in the conventional turbine meter, as the flow rate becomes lower, the meter delays from the actual flow rate (generally called minus instrumental error). / Every minute, the instrumental error exceeds -1%, and when the flow rate is less than that, the instrumental error suddenly worsens to the negative side, so it cannot be used at low flow rates. On the other hand, in this embodiment, 3
At -5 liters / minute, a phenomenon occurs in which the meter slightly advances with respect to the actual flow rate (generally called plus instrumental error), and the instrumental error is -1%.
The flow rate that becomes worse toward the negative side is approximately 2.2 liters / minute. This is improved by the configuration of the present invention so that the frictional resistance of the bearing portion in the low flow rate region is reduced, and the turbine rotor is rotating accurately in proportion to the flow rate from a smaller flow rate than the conventional one. Shows.

[0011]

As is apparent from the above embodiments, the present invention comprises a turbine rotor provided in a fluid passage and a bearing member for rotatably supporting the turbine rotor,
A flow meter for measuring the flow rate by detecting the rotation of a magnet attached to a turbine rotor with a magnetic sensor, wherein a cemented carbide sphere is fixed to both ends of the turbine shaft of the turbine rotor, and a bearing surface supporting this sphere is formed. This is a turbine meter provided with a bearing for an artificial jewel formed on a concave spherical surface. According to the present invention, since the spherical body fixed to both ends of the turbine shaft is supported by the bearing formed in the concave spherical surface, the contact resistance between the shaft and the bearing is small, and the rotation of the turbine rotor is loaded even in the low flow rate region. Is given less, and it rotates accurately in proportion to the flow rate up to the low flow rate range. In addition, since the bearing of the artificial jewel formed on the sphere of cemented carbide and the concave spherical surface is used, there is no wear, and therefore a large effect that the flow rate can be measured with a high accuracy from a small flow rate over a long period of time was obtained.

[Brief description of drawings]

FIG. 1 is a front sectional view of a turbine meter of the present invention.

FIG. 2 is an enlarged cross-sectional view of a turbine rotor and a bearing portion of FIG.

FIG. 3 is a left side view of FIG.

FIG. 4 is a right side view of FIG.

FIG. 5 is a performance curve of a turbine meter.

[Explanation of symbols]

 1 meter main body 2 inflow side connecting member 3 outflow side connecting member 4 sealing member 5 front guide member 5a straightening plate 6 rear guide member 6a rib portion 7 pressing ring 8 turbine rotor 9 impeller 10 turbine shaft 11 spherical body 12 bearing 12a concave spherical surface 13 Protective member 14 Magnet 15 Adjustment shaft 16 Nut 17 Pressure-resistant cover 18 Seal ring 19 Magnetic sensor A Axis core wire

Claims (1)

[Claims] 1. A turbine rotor provided in a fluid flow path, and a bearing member for rotatably supporting the turbine rotor, wherein the rotation of a magnet attached to the turbine rotor is detected by a magnetic sensor to measure a flow rate. In the flow meter, the turbine meter is characterized in that cemented carbide spheres are fixed to both ends of the turbine shaft of the turbine rotor, and bearings for artificial jewels in which a bearing surface for supporting the spheres is formed into a concave spherical surface are provided. .