JP3063809B2 - Volumetric flow meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive displacement flowmeter, and more particularly to a structure in which the rotation of one rotor is transmitted to another rotor via a timing gear fitted to the rotation shafts of a pair of rotors. Volumetric flowmeter.

[0002]

2. Description of the Related Art For example, one of flow meters has a pair of non-contact type rotators (rotating bodies for flow measurement) formed in the form of eyebrows. There are roots-type positive displacement flowmeters. As this type of positive displacement flowmeter,
For example, there is a flow meter configured as shown in FIG.

In FIG. 1, a pair of roots-type rotors 2a and 2b are provided in a measuring chamber 1a of a casing 1,
a and 2b are supported by rotating shafts 3a and 3b. The rotating shafts 3a and 3b are provided integrally with the rotors 2a and 2b, respectively, and are rotatably supported by bearings 4 of the side plates 1b and 1c of the casing 1.

A rotation detecting magnet 5 is fixed to one end of one of the rotating shafts 3a. The lid 6 facing the magnet 5 is provided with a magnetic sensor 7 for detecting the rotation of the magnet 5 and a flow rate indicator 6a for displaying the measured flow rate. The rotating shafts 3a, 3b projecting into the lid 8 of the side plate 1c opposite to the lid 6.
The other end is provided with timing gears 9a and 9b that mesh with each other.

Therefore, the rotors 2a and 2b are connected to the rotating shafts 3a and
Rotational driving forces are transmitted to each other via timing gears 9a and 9b fitted to the other end of 3b, whereby the rotation is smoothly performed at a rotation speed corresponding to the flow rate.

[0006]

However, in the above-described conventional configuration, for example, when inspection or repair is performed, one of the lids 6 is removed, so that the flow rate indicating section 6a, the magnetic sensor 7, the magnet 5, and the bearing 4 are connected. The inspection can be performed, and by removing the cover 8 on the opposite side, the rotating shafts 3a, 3b, the timing gears 9a, 9
b. The bearing 4 can be inspected. Furthermore, conventionally,
Remove the rotating shafts 3a, 3b and the timing gears 9a, 9b, then remove the side plates 1b, 1c of the casing 1 and remove the rotors 2a, 2c.
b will be taken out of the casing 1. Therefore, in the conventional configuration, both lids 6 and 8 on both sides must be removed from the casing 1 at the time of inspection, and especially the rotors 2a and 2b
It is necessary to remove and disassemble all parts in order to inspect, and not only a considerable amount of labor is required at the time of inspection, but also a problem that inspection work requires much labor and time.

In addition, during the assembling operation, each component must be assembled from both sides of the casing 1, and the assembling operation is troublesome and difficult to assemble in a short time.

Conventionally, since only one magnet 5 is provided at the end of the rotating shaft 3a, the rotors 2a and 2b are
Two pulses of the north pole and the south pole were detected during the rotation. However, when the number of pulses per rotation of the rotors 2a and 2b is increased to improve the flow rate measurement accuracy, the end of the rotation shaft 3a has a larger diameter than the rotation shaft 3a so that a plurality of magnets 5 can be attached. It is necessary to provide a magnet mounting part.
In this case, the rotating shaft 3a does not come off to the timing gear 9a side, so that the maintenance workability is further reduced and the work such as inspection and repair becomes troublesome.

[0009] Therefore, an object of the present invention is to solve a volumetric flowmeter which has solved the above-mentioned problems.

[0010]

According to the first aspect of the present invention,
A pair of non-contact type rotors rotatably provided in the measuring chamber through which the fluid passes, and a pair of rotations so as to transmit the rotation of one of the pair of rotors to the other rotor. A timing gear provided on the rotating shaft of the child, a magnet for rotation detection provided on at least one of the pair of rotating shafts, and a sensor for outputting a signal corresponding to the rotation of the magnet, A flow indicator that integrates the signal from the sensor and displays the flow rate, wherein the timing gear is provided between the rotor and the flow indicator. .

The invention according to claim 2 is characterized in that a rotation detecting means for detecting rotation of the rotating shaft is provided between the timing gear and the flow rate indicating section.

Further, the invention according to claim 3 is characterized in that the rotation detecting means is provided at an end of a rotation shaft passing through the timing gear,
A rotating body having a diameter larger than the outer diameter of the rotating shaft, a plurality of magnets arranged in an annular shape on the rotating body, and a signal provided in opposition to the plurality of magnets, the signal corresponding to the rotation of the plurality of magnets And a sensor that outputs

[0013]

According to the first aspect of the invention, by providing the timing gear between the rotor and the flow indicator, the flow indicator, the rotating shaft and the timing gear can be removed from one direction.
Disassembly at the time of inspection is easy, the inspection work can be performed efficiently, and the assembling work can be performed in a short time.

According to the second aspect of the present invention, a rotation detecting means for detecting the rotation of the rotating shaft is provided between the timing gear and the flow indicator, whereby the flow indicator, the rotating shaft and the timing adjuster are provided. Inspection can be performed by removing the rotation detection means from one direction together with the gear.

According to the third aspect of the present invention, the rotation detecting means includes a rotating body having a diameter larger than the outer diameter of the rotating shaft, a plurality of magnets annularly arranged on the rotating body, and a plurality of magnets. Since it consists of a sensor that outputs a signal according to the rotation, a plurality of magnets and sensors can be removed from one direction along with the flow rate indicator, the rotating shaft, and the timing gear, and the sensor can be inspected. Increase the flow rate measurement accuracy.

[0016]

1 to 3 show one embodiment of a volume flow meter according to the present invention.

In each of the figures, a volume flow meter 11 is provided, for example, in the middle of a pipe (not shown) for feeding a fluid, and measures the flow rate of the fluid flowing in the pipe. It is composed of

A casing 12 has an inlet 12a inside.
And a flow channel 12c that communicates with the outlet 12b.
A measuring chamber 13 is provided in the middle of 2c. The casing 12 has an opening 13a on one side of the measuring chamber 13 (the left side of the casing 12 in FIG. 1) and a side wall 13b on the other side. A pair of eyebrow-shaped rotors 14, 15 inserted from the opening 13a are assembled in the measuring chamber 13 with a phase difference of 90 degrees, and the pair of rotors 14, 15 rotate in a non-contact state. The rotating shafts 16, which are press-fitted into the central holes, respectively,
17 supported.

A side lid 18 for closing the opening 13a of the measuring chamber 13 is screwed to one side surface 12d on one side of the casing 12. A side cover 19 for hiding the ends of the rotating shafts 16 and 17 is screwed to the other side surface 12 e of the casing 12. The side covers 18 and 19 have a bearing 20 for bearing the ends of the rotating shafts 16 and 17 and a measuring chamber 13.
An O-ring 21 is mounted to prevent leakage.

Further, a cup-shaped cover 22 that covers the outside of the side cover 18 is screwed to the side cover 18. Incidentally, an O-ring 23 is interposed between the cover 22 and the side cover 18,
The inside of the cover 22 is hermetically sealed.

One end (the left end in FIG. 1) of the rotary shafts 16 and 17 penetrates the side cover 18 and protrudes into a space 24 formed by the cover 22 and the side cover 18. The other ends (right ends in FIG. 1) of the rotating shafts 16 and 17 are fitted to the bearing 20 but do not protrude outside the bearing 20. Since the screw 25 is screwed into the other end of each of the rotating shafts 16 and 17, the end of the screw 25 can be viewed by removing the side cover 19 from the casing 12, whereby the pair of rotors 14 and 17 can be seen. It can be confirmed that 15 is rotating.

The pair of rotors 14 and 15 are combined with each other via a minute clearance, and rotate while maintaining a minute clearance with respect to the inner wall of the flow chamber 13. Further, since the pair of rotors 14 and 15 are provided with a shift of 90 degrees, rotational force due to fluid pressure is alternately applied. Therefore, time adjusting gears 26 and 27 for adjusting the timing when the pair of rotors 14 and 15 rotate are fitted and fixed to one ends of the rotating shafts 16 and 17. The timing gears 26 and 27 mesh with each other in the space 24,
Rotational force generated when the pair of rotors 14 and 15 rotates at a rotation speed corresponding to the flow rate is transmitted to the rotation shafts 16 and 17 via the timing gears 26 and 27, respectively. In other words, when one of the rotors 14 and 15 is driven to rotate, the other is transmitted to the other via the timing gears 26 and 27 and rotates at the same rotational speed while maintaining a non-contact state with each other.

The timing gears 26 and 27 are a pair of rotors 1
Since the cover 22 is provided between the casing 12 and the flow indicator 32, the rotation shafts 16 and 17, and the timing gear 2
6, 27 can be removed from one direction. This allows
Disassembly at the time of inspection becomes easy, and the inspection work of the flow rate indicating part 32, the rotating shafts 16, 17 and the timing gears 26, 27 can be performed in a short time, the inspection work can be performed efficiently, and the assembling work can be performed in a short time. Can be done with

At one end of the rotating shaft 16 penetrating the timing gear 26, a disk-shaped magnet holding portion (rotating body) 28 having a diameter larger than the outer diameter of the rotating shaft 16 and rotating integrally with the rotor 14 is provided. Is provided. On the end surface 28a of the magnet holding portion 28,
As shown in FIGS. 3A and 3B, a plurality (8 in this embodiment)
Pieces of the magnets 29a to 29h are arranged at regular intervals (in this embodiment,
(Every 45 °). The magnets 29a to 29h
Are buried in a direction such that N poles and S poles are alternately arranged on the end face 28a side of the magnet holding portion 28.

Numeral 30 denotes a magnetic sensor for outputting a signal corresponding to a magnetic change, and the magnets 29a to 29h of the magnet holding portion 28 are provided.
4 is inserted into the mounting hole 22a of the cover 22 so as to be close to.
A signal as shown in FIG. The magnet holding part 2
8, rotation detecting means for detecting rotation of the rotors 14 and 15 by the magnets 29a to 29h and the magnetic sensor 30 is configured.

Since the rotation detecting means is provided between the timing gears 26 and 27 and the flow indicator 32, the flow indicator 32, the rotating shafts 16 and 17, and the timing gears 26 and 27 will be described later. At the same time, the rotation detecting means (the magnet holding section 28, the magnets 29a to 29h, and the magnetic sensor 30) can be removed from one direction for inspection.

When the fluid flows through the flow path 12c of the casing 12, the pair of rotors 14 and 15 move A and B as shown in FIG.
Rotate in the direction. A space 31 as shown by hatching in FIG. 2 is formed between the rotors 14 and 15 and the measuring chamber 13, and as the rotors 14 and 15 rotate, a volume of fluid in the space 31 is supplied to the outlet 12 b side. Sent to

Numeral 32 is a flow rate instructing section, which is provided on the cover 22 and houses therein an arithmetic circuit (not shown) for integrating the flow rate. The flow sensor 32 includes a magnetic sensor 3
0 is input, and this signal is
The waveform is shaped into a detection pulse as shown in FIG. Therefore, when the magnetic sensor 30 outputs a signal corresponding to the rotation speed of the rotor 14, the arithmetic circuit of the flow rate instruction unit 32
The flow rate is calculated from the number of rotations 4 and the volume of the space 31.

In this embodiment, the end surface 28 of the magnet holding portion 28
Since eight magnets 29a to 29h are embedded at a constant interval in a, eight pulses are detected while the rotors 14, 15 make one rotation. Therefore, the rotors 14, 1
The number of pulses for the rotation of 5 is increased, and the flow rate measurement accuracy is improved accordingly.

Further, the rotation detecting magnets 29a to 29a-2
Magnet holding portion 28 having a diameter of 9 h and a diameter larger than the outer diameter of the rotating shaft 16
Are provided on the timing gears 26 and 27, so that FIG.
Remove the cover 22 in order from the middle left and remove the magnets 29a to 29h.
And the timing gears 26, 27 can be inspected, and then the rotors 14, 15 can be inspected by removing the side cover 18. Therefore,
When performing inspection, repair, etc., the large-diameter magnet holding portion 28 and the timing gear 2 can be easily removed by removing the cover 22 and the side cover 18.
6, 27 and the rotors 14 and 15 can be taken out, and maintenance work can be performed efficiently.

When assembling the volumetric flowmeter 11, the rotors 14, 15 and the rotating shafts 16, 17,
Since the side cover 18, the timing gears 26 and 27, and the cover 22 may be assembled, the assembly can be performed efficiently in a short time.

In the above-described embodiment, the flow indicator 32 is provided on the side surface of the cover 22. However, the present invention is not limited to this. It is good also as a structure which displays a flow rate above.

In the above embodiment, the magnet holding portion 28
Although the magnets are provided for each of them, the number is not limited thereto, and eight or less or eight or more may be provided. By providing eight or more magnets, it is possible to increase the flow rate measurement accuracy more than in the above embodiment.

[0034]

As described above, according to the first aspect of the volume flow meter according to the present invention, since the timing gear is provided between the rotor and the flow rate indicating section, the flow rate indicating section, the rotating shaft, and the adjusting section are provided. The hour gear can be removed from one direction, so that it can be easily disassembled at the time of inspection, and inspection work can be performed efficiently and assembly work can be performed in a short time. Furthermore, since the magnet, timing gear, and rotor can be removed from one direction, inspection and repair can be performed easily, and maintenance work can be performed in a short time. It can be assembled well and the manufacturing cost can be reduced.

According to the second aspect of the present invention, since the rotation detecting means for detecting the rotation of the rotating shaft is provided between the timing gear and the flow indicator, the flow indicator, the rotating shaft and the timing gear are provided. At the same time, the rotation detecting means can be removed from one direction for inspection.

According to the third aspect of the present invention, the rotation detecting means includes: a rotating body having a diameter larger than the outer diameter of the rotating shaft; a plurality of magnets annularly disposed on the rotating body; Since it consists of a sensor that outputs a signal according to the rotation, a plurality of magnets and sensors can be removed from one direction along with the flow rate indicator, the rotating shaft, and the timing gear, and the sensor can be inspected. It has the advantage that the flow measurement accuracy can be increased by increasing it.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a volume flow meter according to the present invention.

FIG. 2 is a longitudinal sectional view showing a rotor and a measuring chamber.

FIG. 3 is an enlarged view for explaining a magnet holding portion in which a plurality of magnets are embedded.

FIG. 4 is a waveform diagram of a signal detected by a magnetic sensor and its pulse.

FIG. 5 is a longitudinal sectional view for explaining a conventional positive displacement flow meter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Volumetric flow meter 12 Casing 13 Measuring chamber 14, 15 Rotor 16, 17 Rotating shaft 18 Side cover 22 Cover 26, 27 Timing gear 28 Magnet holding part 29a-29d Magnet 30 Magnetic sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-247527 (JP, A) JP-A-1-1355731 (JP, A) JP-A-63-111620 (JP, A) 185222 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01F 3/10

Claims (3)

(57) [Claims] 1. A non-contact type pair of rotors rotatably provided in a measuring chamber through which a fluid passes, and the rotation of one of the pair of rotors is transmitted to another rotor. A timing gear provided on the rotating shafts of a pair of rotors, a rotation detecting magnet provided on at least one of the pair of rotating shafts, and a signal corresponding to the rotation of the magnets. In a positive displacement flowmeter having a sensor to output and a flow rate indicator for integrating a signal from the sensor and displaying a flow rate, the timing gear is provided between the rotor and the flow rate indicator. A volume flow meter characterized by the above. 2. A positive displacement flowmeter according to claim 1, further comprising a rotation detecting means for detecting rotation of said rotary shaft between said timing gear and said flow rate indicating section. 3. The rotation detecting means is provided at an end of a rotating shaft penetrating the timing gear, and a rotating body having a diameter larger than an outer diameter of the rotating shaft; and the rotating body is annularly disposed on the rotating body. The volume flow meter according to claim 2, comprising: a plurality of magnets; and a sensor provided to face the plurality of magnets, and configured to output a signal according to rotation of the plurality of magnets.