JPH08285656A - Shaft rotation transmitting device of wet type gas meter - Google Patents

Abstract

PURPOSE: To prevent a trouble due to abrasion and swelling of an oil seal and a trouble due to friction with an oil seal, and to simplify the structure and reduce the size thereof so as to transmit shaft rotation smoothly and correctly. CONSTITUTION: In order to transmit the rotation of a drum shaft 6 in a measuring casing 1 to an output shaft 53 in a counter casing 1, a main driving magnet disc 71 which is axial anisotropic is fixed in the vicinity of the casing front wall 1a in such a manner as to be aligned with the axis of the drum shaft 6, and an axial anisotropic driven magnet disc 72 which is rotated following the main driving magnet disc 71 by magnetic adsorption is fixed in the vicinity of the casing front wall 1a of the output shaft 53 in such a manner as to be opposite to the main driving magnet disc 71 with the casing front wall 1a interposed between them and be aligned with the axis of the output shaft 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft rotation transmission device for a wet gas meter for transmitting rotation of a drum shaft in a measuring casing to an output shaft in a counter box.

[0002]

2. Description of the Related Art FIG. 3 is a side sectional view showing a conventional general wet gas meter. As shown in the figure, the wet gas meter includes a measuring casing (1) and a counter box (2) provided on the front side of the casing (1).
It has and.

Inside the measuring casing (1) is a partition plate (1
A cylindrical drum (5), which is separated into a front chamber and a rear chamber by c), is separated into a plurality of measuring chambers (4) arranged in the circumferential direction inside the rear chamber. The drum shaft (6) of this drum (5) is rotatably supported at its rear end by the rear wall (1b) of the weighing casing (1) via a rear bearing device (7) and has a front portion at the front. In a state of penetrating the wall (1a), the front wall (1a) is rotatably supported by the front bearing device (8). Furthermore, the front end of the drum shaft (6) which penetrates the front wall (1a) and is arranged in the counter box (2) is connected to the counter device (2a) housed in the counter box (2).

In this wet gas meter, gas is measured in a state in which the sealing liquid (L) is enclosed in the measuring casing (1) up to a predetermined position higher than the drum shaft (6). That is, when the sample gas is introduced into the front chamber of the measuring casing (1) through the gas introduction port (9a) in that state, the sample gas is sent into the drum (5) through the gas conduction pipe (10). Be done. Further, the sample gas is sequentially introduced into each measuring chamber (4) as the drum (5) rotates, and is discharged from the rear end side of the drum to the rear chamber of the casing (1) to pass through the gas discharge port (9b). It is discharged through the casing (1). During this measurement, the rotation status of the drum (5) is transmitted to the counter device (2a) in the counter box (2) via the drum shaft (6), and the integrated flow rate value of the sample gas is measured there. It is displayed on the front of the counter box (2).

[0005]

By the way, the front bearing device (8) of the conventional wet gas meter described above has a front wall (1a).
A bearing holder (8a) fixed to the bearing, a bearing (8b) for rotatably supporting the drum shaft (6) on the holder (8a), a drum shaft (6) and a holder (8).
and an oil seal (8c) for sealing the gap with a).

However, the oil seal (8c) is
It is usually made of nitrile rubber or the like, and has a problem that it swells due to the sealing liquid (L) to cause liquid leakage. Further, when the oil seal (8c) is worn due to long-term use, there is a problem that liquid leakage may occur or the rotational resistance of the drum shaft (6) may be reduced to cause an instrumental difference change, resulting in a reduction in gas measurement accuracy. It was

Further, in order to prevent swelling due to the sealing liquid (L), if the material of the oil seal (8c) is made of Teflon type, it is hard, so that the load resistance during rotation of the drum shaft increases, and the high performance wet type. Another problem occurs that a gas meter cannot be manufactured.

On the other hand, in recent years, as a shaft rotation transmission device for transmitting the rotation of the drum shaft in the wet gas meter to the counter box side, a device utilizing a magnet coupling has been developed.

A shaft rotation transmission device (11) of that kind is shown in FIG.
The bearing bracket (12) mounted via the mounting ring (11a) in the mounting hole (1d) formed in the front wall (1a) of the weighing casing (1) and the drum shaft (5) side as shown in FIG. Magnet holder fixed to (17)
And have.

The bearing bracket (12) has a bottomed tubular bracket body (12a) and a flange (12b) projecting from the outer periphery of the opening side end portion of the bracket body (12a). Is inserted into the mounting ring (11a) from the counter box (2) side, and the flange (12b) is fixed to the mounting ring (11a) via the packing (13) by screwing.

In the bearing bracket (12), the rear end of the output shaft (14) is arranged inside the bracket (12) and the front end is arranged outside the bracket (12), so that the bearing (15) is formed. ) Is rotatably supported via. Further, the inner magnet cylinder (16a) is fixed to the outer periphery of the rear end of the output shaft (14) in the bearing bracket (12), and the front end of the output shaft (14) is counter device outside the bearing bracket (12). It is connected to (2a).

The magnet holder (17) is in the shape of a cylinder with a bottom, and the bearing bracket body (12a) is housed inside the magnet holder (17) so that one end of the drum shaft (6) penetrates the bottom wall. The drum shaft (6) is fixed and one end of the drum shaft (6) is attached to the bottom wall of the bearing bracket (12).
It is rotatably supported via 8). Further, an outer magnet cylinder (16b) is fixed to the inner peripheral surface of the magnet holder (17) corresponding to the outside of the inner magnet cylinder (16a).

In the shaft rotation transmission device (11) of this structure, the inner magnet cylinder (16
The rotation of the drum shaft (6) is transmitted to the output shaft (14) by utilizing that a) rotates following the outer magnet cylinder (16b).

However, this shaft rotation transmission device (1
1) arranges the inner magnet cylinder (16a) on the side of the counter box (2) inside the outer magnet cylinder (16b) on the side of the measuring casing (1), the inner magnet cylinder (16b) is arranged on the side of the measuring casing (16b). 1) side, and the drum shaft (5) and the output shaft (14) need to be pivotally supported by the protruding portion (bearing bracket 12). There is a problem that it causes an increase in manufacturing cost.

Further, in this device (11), it is necessary to increase the amount of overlap of the magnet cylinders (16a) and (16b) in the axial direction to secure a sufficient transmission force between the two, so that the size in the axial direction is small. This causes a problem that the size of the metering casing (1) becomes large and the gas meter becomes large. Moreover, the outer magnet cylinder (16
Inner magnet cylinder (16) arranged inside b)
In the case of a), the turning radius becomes small, so that a sufficient turning torque cannot be obtained and the shaft rotation cannot be transmitted smoothly.

Further, in the conventional shaft rotating device (11), if an anisotropic magnet is used as the magnet cylinders (16a) and (16b), it is necessary to use an expensive cylinder magnet having an anisotropic radial direction. However, in terms of cost, anisotropic magnets cannot be used, and isotropic magnets are generally used. For this reason both cylinders (16a)
The transmission force between (16b) becomes small, and it is necessary to reduce the dimension between them in order to secure a sufficient transmission force. In addition, as described above, in order to prevent the apparatus from increasing in size, it is not possible to increase the overlapping amount of both cylinders (16a) (16b) in the axial direction.
It is necessary to reduce the dimension between a) and (16b) to secure a sufficient transmission force. As a result, of course, the outer magnet cylinder (16b) and the bearing bracket (12)
There is also a problem in that the gap between the cylinder and the cylinder becomes smaller, and the gap contains impurities, dust, etc. contained in the sealing liquid, so that the cylinder (16b) cannot rotate smoothly, and the shaft rotation cannot be accurately transmitted. It was

Further, particularly when a highly corrosive gas is used as the sample gas, the outer magnet cylinder (16b) is easily corroded, which causes a problem that stable shaft rotation cannot be transmitted for a long period of time. To do.

On the other hand, in the wet gas meter, since the casing (1) is mainly made of sheet metal, if both magnet cylinders (16a) (16b) are axially overlapped as described above, both cylinders (16a). ) (1
It is practically impossible to partition 6b) with a single plate. Therefore, the casing front wall (1
It is necessary to form a through hole such as the mounting hole (1d) in a) and separate the two cylinders (16a) and (16b) by the bracket (12) mounted in the hole. However, once the through hole (1d) is formed in the front wall (1a) of the casing, it is difficult to ensure a perfect sealing property even if the bracket (12) is closed later. There is.

The present invention solves the above-mentioned problems of the prior art, can prevent problems such as liquid leakage and instrumental error due to wear and swelling of the oil seal, and can increase frictional resistance against the rotation of the oil seal due to friction with the oil seal. A shaft rotation transmission device for a wet gas meter that uses a magnetic coupling system that can prevent malfunctions.It has a simple structure that can reduce costs and reduce the size of the device, and can transmit shaft rotation accurately and smoothly. In addition, it is necessary to provide the one that can ensure the perfect sealing property between the measuring casing and the counter box, and further, to provide the one that can effectively prevent the adverse effect on the magnet due to the dust in the sealing liquid and the trouble due to the corrosion of the magnet. With the goal.

[0020]

To achieve the above object, according to the present invention, both ends of the drum shaft of a measuring drum housed in the measuring casing are rotatably supported inside the front and rear walls of the measuring casing. For transmitting the rotation of the drum shaft to the output shaft in a wet gas meter in which an output shaft is rotatably provided coaxially with the drum shaft in a counter box provided on the front surface side of the front wall of the measuring casing. A shaft rotation transmission device for a wet gas meter, wherein an axially anisotropic main drive magnet disk is fixed in the vicinity of a front wall of the casing of the drum shaft in a state where the axial line of the drum shaft is aligned with the drum shaft. The driving magnet disk is magnetically attracted in a manner to face the driving magnet disk near the front wall with the front wall of the casing interposed therebetween. Driven magnet disk axial anisotropy rotation followability to is summarized as made fixed in a state of being matched with the axis and the output shaft.

In the present invention, the driving magnet disk is fixed to the drum shaft via a magnet holder, and a magnet cover for covering the exposed area of the driving magnet disk is attached to the magnet holder. It is preferable to adopt the configuration as described below.

[0022]

In the shaft rotation transmission device of the wet gas meter according to the present invention, the main drive magnet disk is fixed to the end of the drum shaft in the measuring casing, and the end of the output shaft in the counter box is opposed to the main drive magnet disk and is driven by the driven magnet. Since the disk is fixed and the rotation of the drum shaft is transmitted to the output shaft in a non-contact manner by the magnetic attraction of both disks, it is compared with, for example, a shaft-through type in which the drum shaft penetrates the front wall of the casing. In this case, it is possible to reliably prevent problems such as liquid leakage and changes in instrumental differences due to wear and swelling of the oil seal, and it is possible to reliably prevent problems due to friction with the oil seal, such as an increase in rotational load resistance.

The present invention has a simple structure in which both discs are opposed to each other with the front wall of the casing interposed therebetween, and since a thinner magnet disc is disposed along the front wall of the casing, the size in the axial direction of the drum is increased. Can be made smaller. Further, since the driven magnet disk has a large turning radius like the driving magnet disk, a sufficient rotation torque can be obtained and the shaft rotation can be transmitted smoothly.
Moreover, since the magnet disk is anisotropic, a sufficient transmission force can be obtained between the two disks without causing an adverse effect such as an increase in size in the axial direction. In other words, the gap between the driving magnet disk and the front wall can be formed with some margin, and it is possible to prevent impurities and the like in the sealing liquid from clogging the gap.

Further, the structure of the present invention can be realized without forming any through hole or the like in the front wall of the casing, in which case the measuring casing and the counter box are separated by the front wall of the single plate. Is possible.

In the present invention, the magnet holder is
If a magnet cover is attached to cover the exposed area of the driving magnet disk, the driving magnet disk can be shielded from the surrounding atmosphere, especially when measuring highly corrosive sample gas. In addition to preventing the above, it is possible to prevent adverse effects on the magnet due to dust and the like in the sealing liquid.

[0026]

1 is a side sectional view showing the vicinity of a shaft rotation transmitting device of a wet gas meter to which an embodiment of the present invention is applied, FIG.
FIG. 3 is a side sectional view showing the shaft rotation transmitting device in an exploded manner.

As shown in both figures, this wet gas meter has the same structure as the above-mentioned conventional example except for the shaft rotation transmission device (30), and is a cylindrical measuring drum (5).
And a measuring casing (1) that is housed in a state where the container is immersed in the sealing liquid (L) up to a predetermined position, and the measuring casing (1).
And a counter box (2) provided on the front surface of the front wall (1a). Furthermore, a mounting hole (1d) is formed in the front wall (1a) of the measuring casing (1) in correspondence with the arrangement position of the drum shaft (6).
A mounting ring (21) is fixed by welding along the peripheral portion of d).

The shaft rotation transmitting device (30), which is the point of this embodiment, includes a main magnet holder (40) arranged on the side of the measuring casing (1) and a driven magnet holder arranged on the side of the counter box (2). (50)
And a bearing bracket (60) disposed between the magnet holders (40) and (50).

First, the bearing bracket (60) has a substantially disc shape, and has a flange (61) along the outer peripheral edge.
Is provided, and shaft support pins (62) and (63) projecting on both sides along the axis are provided at the center position.

Then, the bearing bracket (60) closes the mounting hole (1d) of the casing front wall (1a) from the counter box (2) side, and the flange (61).
Are superposed on the mounting ring (21) via the packing (22), and in this state, the flange (61) is screwed (6).
It is fixed to the mounting ring (21) by 2).

The driving magnet holder (40) has a recess (41) for axial support formed in the center of the front side and a magnet mounting recess (42) in the shape of a donut along the outer peripheral edge of the front side. There is. Further, a shaft fixing recess (43) is formed in the center of the rear surface side.

In the magnet mounting recess (42) of the magnet holder (40), a driving magnet disk (a donut type) ferrite magnet having four poles arranged in the circumferential direction and having axial anisotropy (a donut type) is used. 71)
Are fixed with their axes aligned with the holder (40). Further, a donut-shaped magnet cover (70) made of a material having excellent corrosion resistance such as stainless steel or vinyl chloride so as to cover the front exposed portion of the disk (71).
Is attached. In this case, the driving magnet disk (71) is configured such that the entire outer peripheral surface thereof is covered with the magnet holder (40) and the magnet cover (70).

The front end of the drum shaft (6) fixed along the axis of the drum (5) is inserted into the shaft fixing recess (43) of the magnet holder (40) and fixed by screwing. It At this time, the axis of the magnetic disk (71) is configured to coincide with the axis of the drum shaft (6).

Then, this magnet holder (40)
The inner side of the shaft support concave portion (41) of the shaft support pin (6) of the bearing bracket (60) is inserted through the bearing (44).
It is rotatably supported by 2). The rear end side of the drum shaft (6) is rotatably supported on the rear wall of the measuring casing (1) via a bearing device as in the conventional case.

The driven magnet holder (50) has a recess (51) for axial support formed in the center of the rear surface side, and a donut-shaped magnet mounting portion (52) formed along the outer peripheral edge of the rear surface side. There is. Furthermore, in the center of the other side,
An output shaft (53) is provided so as to project along the axis.

The magnet mounting portion (52) of the holder (50) is composed of an axially anisotropic disc type (doughnut type) ferrite magnet having four poles arranged in the circumferential direction. A driven magnet disk (72) of the same size as the disk (71) is fixed in a state of being aligned with the axis of the holder (50).

And this magnet holder (50)
The inner side of the shaft support recess (51) of the shaft support pin (6) of the bearing bracket (60) is inserted through the bearing (54).
3) is rotatably supported, whereby the driven magnet disk (72) is arranged in a state of being coaxially opposed to the driving magnet disk (71) with the bearing bracket (60) interposed therebetween.

In the counter box (2),
A counter device (2
a) is provided, and the gas flow rate can be measured based on the rotation of the output shaft (53).

Further, an oil seal (45) for preventing the sealing liquid (L) from entering the bearing (44) side is mounted in the shaft support recess (41) of the driving magnet holder (40). ing.

In this wet gas meter, when the drum (5) is rotated and the drum shaft (6) is rotated by the introduction of the sample gas, the driving magnet disk (71) is rotated along with the rotation. Further, due to magnetic attraction, the driven magnet disk (72) rotates following the driving disk (71), and the output shaft (53) rotates. In this way, while the output shaft (53) rotates corresponding to the drum (5), the integrated flow rate value of the sample gas is measured by the counter device (2a) from the rotation status of the output shaft (53) and displayed on the front of the counter box. It

According to this wet gas meter, as the shaft rotation transmission device (30), the rotation of the drum shaft (5) in the measuring casing (1) is magnetically attracted to the output shaft (53) in the counter box (2). Since the magnetic coupling type that transmits in a non-contact manner is used, the front wall (2
Shaft penetration type in which the drum shaft is penetrated in a) (see Fig. 3)
Compared with the above, it is possible to reliably prevent problems due to wear and swelling of the oil seal, such as liquid leakage and changes in instrument differences, and to prevent problems due to friction with the oil seal, such as an increase in rotational load resistance. It is possible to maintain high measurement accuracy.

The shaft rotation transmission device (30) has two
Since a disk type magnetic coupling in which two magnetic disks (71) and (72) are arranged to face each other with a substantially disk-shaped bearing bracket (60) interposed therebetween is used, for example, a cylinder type magnetic coupling is used. Compared with the shaft rotation transmission device (see FIG. 4), the structure is simplified, and the manufacturing cost can be reduced and the assembling work can be facilitated. Moreover, the driven magnet disk (72) is the driving magnet disk (71).
Similar to the above, since the turning radius is large, a sufficient turning torque can be obtained, and the shaft rotation can be transmitted smoothly.

Furthermore, in this embodiment, since the magnetic disks (71) and (72) are anisotropic, a strong magnetic attraction force can be obtained and the axial rotation can be transmitted more accurately. In this embodiment, the disc (71)
Although an anisotropic magnet is used as (72), an increase in cost can be avoided. That is, when an anisotropic magnet is used as a magnet cylinder in the conventional cylinder type magnet coupling type axial rotation transmitting device shown in FIG. 4, it is necessary to use an expensive radial direction anisotropic cylinder type magnet. is there. On the other hand, in the present embodiment, relatively inexpensive axial direction anisotropic disk type magnets can be used as the disks (71) and (72), and an increase in cost can be avoided.

Further, in this embodiment, a magnet disk (7) which is thin in the axial direction is provided in the measuring casing (1).
Since 2) is simply arranged along the casing front wall (1a), the space inside the measuring casing (1) is not restricted, and the interior space for mounting the casing interior parts such as the drum (5) and the gas conducting pipe. It is possible to reduce the size of the device while sufficiently securing the above.

On the other hand, the main drive magnet disk (71) on the side of the measuring casing (1) has a magnet holder (4).
0) and the magnet cover (70) cover the entire outer peripheral surface, so that the driving magnet disk (7)
1) can be reliably shielded from the ambient atmosphere, even when measuring a highly corrosive sample gas, the magnet disk can be reliably prevented from corroding, and the magnet disk (71) due to dust etc. in the sealing liquid It is possible to surely prevent the adverse effect of, and to achieve stable transmission of shaft rotation over a long period of time.

Further, a sufficient transmission force can be secured between the two discs (71) and (72) without causing any adverse effect such as an increase in size in the axial direction. ) And bearing brackets (60)
A wide gap can be formed with a margin. Therefore,
Impurities and dust contained in the sealing liquid are not clogged in the gap, and smooth shaft rotation can be transmitted for a long time.

Further, since the oil seal (45) for sealing the bearing (44) is mounted in the shaft support recess (41) of the driving magnet holder (40), the oil is removed from the driving magnet disk (71). The bearing (44) is not deteriorated by the sealing liquid (L) entering through the gap with the bearing bracket (60).

In the present invention, since the two magnet disks (71) and (72) are separated from each other in the axial direction, the two disks (71) and (72) are separated by one plate (the front wall of the casing). It is possible to realize the constitution of the present invention without forming any through hole such as the mounting hole (1d) in the front wall (1a) of the measuring casing (1). For example, by directly supporting the drum shaft (6) to which the magnet disks (71) (72) are fixed and the output shaft (53) on the front wall (1a) without using the bearing bracket (60) or the like. The configuration of the present invention can be realized without forming any through holes or the like in the front wall (1a) of the casing. When this configuration is adopted, the casing (1) and the counter box (2) can be separated by the one-plate front wall of the casing, and a perfect sealing property can be secured between the both (1) and (2).

[0049]

As described above, in the shaft rotation transmission device for a wet gas meter according to the present invention, the main drive magnet disk is fixed to the end of the drum shaft in the measurement casing, and the output shaft in the counter box faces the main drive magnet disk. Then, the driven magnet disc is fixed and the rotation of the drum shaft is transmitted to the output shaft in a non-contact manner by magnetic attraction of both discs. When compared to
It is possible to reliably prevent problems due to wear and swelling of the oil seal, such as liquid leakage and change in instrumental error, and to prevent problems due to friction with the oil seal, such as an increase in rotational load resistance. Further, since both disks have a simple structure in which they are opposed to each other with the front wall of the casing interposed therebetween, the manufacturing cost can be reduced and the assembling work can be facilitated. Further, since the thin magnet disk is simply arranged along the front wall of the casing in the measuring casing, the size in the axial direction of the drum can be reduced and the device can be downsized. Further, since the driven magnet disk has a large turning radius like the driving magnet disk, a sufficient rotating torque can be obtained and the shaft rotation can be transmitted accurately and smoothly. Moreover, since an anisotropic magnet disk is used, a sufficient transmission force between both disks can be secured, and a gap between them, in other words, a gap between the driving magnet disk and the casing front wall can be formed with a margin. . Therefore, it is possible to prevent impurities and the like in the sealing liquid from being clogged in the gap, so that the shaft rotation can be transmitted more accurately and reliably. In the present invention, an anisotropic magnet is used as the magnet disk, but since this magnet is a relatively inexpensive axial direction anisotropic disk type magnet,
The increase in cost can be avoided.

Further, the structure of the present invention can be realized without forming any through holes or the like in the front wall of the casing. In that case, the front wall of the casing of one plate separates the measuring casing and the counter box. The effect of being able to separate and ensuring a perfect sealing property between the two is obtained.

In the present invention, the magnet holder is
When installing a magnet cover to cover the exposed area of the driving magnet disk, the driving magnet disk can be reliably shielded from the surrounding atmosphere, and the adverse effect on the magnet due to corrosion of the magnet disk and dust in the sealing liquid is prevented. This has the advantage that stable shaft rotation can be transmitted over a long period of time.

[Brief description of drawings]

FIG. 1 is a side sectional view showing the vicinity of a shaft rotation transmission device of a wet gas meter to which an embodiment of the present invention is applied.

FIG. 2 is a side sectional view showing the shaft rotation transmitting device of the embodiment in an exploded manner.

FIG. 3 is a side sectional view schematically showing a conventional wet gas meter.

FIG. 4 is a partially cutaway side view showing the periphery of a shaft rotation transmission device in another conventional wet gas meter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Measuring casing 1a ... Front wall 2 ... Counter box 30 ... Shaft rotation transmission device 40 ... Driving magnet holder 53 ... Output shaft 70 ... Magnet cover 71 ... Driving magnet disk 72 ... Followed magnet disk

Claims (2)

[Claims] 1. A counter box provided on the front side of the front wall of the measuring casing while both ends of a drum shaft of a measuring drum housed in the measuring casing are rotatably supported inside the front and rear walls of the measuring casing. In the wet gas meter in which the output shaft is rotatably provided on the coaxial line with the drum shaft, there is provided a wet gas meter shaft rotation transmission device for transmitting the rotation of the drum shaft to the output shaft. An axially anisotropic main drive magnet disk is fixed near the front wall of the casing with the axis of the drum shaft aligned, and the main drive magnet disk and the front wall of the output shaft are sandwiched near the front wall of the casing. In the aspect facing with,
A shaft rotation transmission of a wet gas meter, characterized in that an axially anisotropic driven magnet disc that rotates following the main drive magnet disc by magnetic attraction is fixed in a state where the axis line coincides with the output shaft. apparatus. 2. The driving magnet disk is fixed to the drum shaft via a magnet holder,
The shaft rotation transmission device for a wet gas meter according to claim 1, wherein a magnet cover for covering the exposed area of the driving magnet disk is attached to the magnet holder.