JPH0432582Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a gas meter counter transmission device,
In particular, it relates to a transmission mechanism that transmits the movement of a crank mechanism of a measuring instrument housed in a case to a counter mechanism provided outside the case.

BACKGROUND ART Conventionally, in a gas meter in which a counter mechanism is attached to the outside of the front of a case containing a built-in meter, power is transmitted from the meter to the counter mechanism by rotational transmission that passes through the front wall of the case via a shaft sealing device. It was supposed to be done through a shaft.

Technical issues to be solved by the invention However, as long as the transmission shaft is installed through the case, there is a risk of gas leaking from the penetrating portion of the transmission shaft. The durability of the shaft sealing device itself has been limited due to swelling and deterioration caused by contact with the shaft sealing device, resulting in great disadvantages in terms of maintenance such as repair and inspection.

This idea was aimed at fundamentally solving the problems mentioned above, and by using a magnetic coupling to perform contactless power transmission, it achieved the intended purpose. This is what we were able to achieve.

Means for Solving the Problems Namely, the gas meter counter transmission device according to this invention is a cylindrical one with one end open and the other end closed in a through hole 12 bored in the front cover of a case 1 housing a measuring instrument 2. A blind cylindrical main shaft holding cylinder 11 is press-fitted and fixed in an airtight state with the open end facing the counter chamber side,
A power transmission main shaft 13 is disposed within the holding cylinder 11, with an inner end formed by a protruding shaft 14 bored in the center of a closed wall at the inner end of the holding cylinder 11, and the other outer end formed by the same. It is rotatably supported by a cylindrical bearing member 15 that is fitted and fixed to the open end of the holding cylinder 11, and a drive gear 16 that meshes with the input gear of the counter mechanism 6 is fixed to the outer end of the transmission main shaft 13. At the same time, a crank member 17 is attached to the inner end of the holding cylinder 11, and the crank member 17 is attached to the transmission main shaft 13 outside the outer peripheral wall of the inner end of the holding cylinder 11 via the wall. A cylindrical portion 17a located opposite to the circumferential surface of the large diameter portion 13a at the inner end of the cylindrical portion, and a plurality of protrusions 17c integrally formed at the inner end of the cylindrical portion and extending radially from the outer circumferential surface. The center portion of the crank blade portion 17b is loosely fitted and rotatably supported by a protruding shaft 18 protruding from the center of the inner end of the holding cylinder 11, and the crank blade portion 17b is rotatably supported. The crank mechanism 5 of the measuring instrument 2 is attached to any one of the pieces 17c.
When the drive pin 19 of the crank member 17 is in contact with the drive pin 19, the drive pin 19 is driven to rotate, and the inner end outer peripheral surface of the main shaft 13 and the cylinder of the crank member 17 are brought into contact with each other. It is characterized in that a plurality of magnetic poles N and S having different poles facing each other are formed on the inner circumferential surface of the shaped portion 17a.

Embodiments Hereinafter, this invention will be further explained in detail based on illustrated embodiments.

In Fig. 1, reference numeral 1 denotes a case formed in two separate parts, an upper case 1a made of a die-casting product and a lower case 1b made of a press-formed sheet metal product, 2 denotes a weighing device as is known and housed and fixed in the case 1, which comprises a weighing box 3, a distributing valve mechanism 4, and a crank mechanism 5. 6 denotes a counter mechanism attached to the outside of the upper front of the case 1, 7 denotes a counter cover which covers the counter mechanism 6 and is fixed in an airtight state to the front of the case, and the part of the counter mechanism 6 facing the display unit is composed of a transparent glass window 8.
is a transmission device according to the present invention for transmitting the movement of the crank mechanism 5 of the weighing device 2 to the counter mechanism 6,
The structure is shown in detail in FIGS.

In these figures, 11 is a blind metal spindle holding cylinder with one end open and the other end closed, and a through hole 12 of a corresponding diameter bored in the front wall of the case 1.
The opening end side faces the counter chamber side, and is press-fitted and fixed in an airtight manner from the outside via a sealing material if necessary. Therefore, the holding cylinder 11 completely hermetically seals the inside and outside of the case 1. Reference numeral 13 denotes a transmission main shaft rotatably supported within this holding cylinder 11, and its inner end is loosely fitted and supported on a protruding shaft 14 bored from the center of a closed wall at the inner end of the holding cylinder 11. At the same time, the other end is rotatably supported by a cylindrical bearing member 15 made of synthetic resin or metal which is similarly fitted and fixed to the open end of the holding cylinder 11. And this transmission main shaft 13 is
The inner end thereof is formed into a large-diameter portion 13a as close as possible to the inner circumferential surface of the holding cylinder 11, and the outer end protruding toward the counter chamber has a drive gear 16.
is fixed and meshed with an input gear (not shown) of the counter mechanism 6, so that the counter mechanism 6 is operated by rotation of the main shaft 13.

Reference numeral 17 denotes a crank member, which is positioned on the outside of the thin outer circumferential wall at the inner end of the holding cylinder 11 so as to face the circumferential surface of the large-diameter portion 13a at the inner end of the transmission main shaft 13 via the wall. cylindrical portion 17a, and a crank blade portion 17b having four protrusions 17c extending radially on the outer circumferential surface integrally formed on the inner end of the cylindrical portion 17a, the crank blade portion 17b is loosely fitted and rotatably supported by a protruding shaft 18 protruding from the center of the inner end of the holding cylinder 11, and the crank mechanism 5 of the measuring instrument 2 is mounted on any one of the radial protrusions 17c. When the drive pin 19 is brought into contact with the drive pin 19, the drive pin 19 passively rotates the drive pin 19.

By the way, on the inner end of the transmission main shaft 13, that is, on the outer circumferential surface of the large-diameter portion 13a and on the inner circumferential surface of the cylindrical portion 17a of the crank member 17, there are two grooves in the circumferential direction in which different poles face each other. A plurality of magnetic poles N and S, approximately 4 to 4, are formed by permanent magnetization. Therefore, as the crank member 17 rotates, the transmission main shaft 13 is driven to rotate at the same rate within the holding cylinder 11 due to the magnetic attraction force of the magnetic poles N and S. Preferably, the magnetic poles N and S are formed by forming the transmission main shaft 13 and the crank member 17 themselves from a polyacetal resin mixed with ferrite powder, and directly magnetizing key points thereof. Although it is advantageous,
It may be formed by attaching separately manufactured permanent magnet pieces to each of the above-mentioned members made of non-magnetic material.

Effect of the Invention Since the counter transmission device according to the invention has the above-mentioned structure, the movement of the crank mechanism 5 of the measuring device 2 is transmitted to the transmission main shaft 13 in the retaining tube 11, which is in a non-contact state, by the rotation of the crank member 17 located outside the retaining tube 11, and further transmitted correctly to the counter mechanism 6 via the driving gear 16. Not only can the intended accurate transmission purpose be achieved, but the inside and outside of the case 1 are completely sealed off by the blind retaining tube 11, and the rotation transmission is performed between the members located inside and outside the case 1, so that there is no need for a shaft seal device for the rotating shaft that passes through the case, and furthermore, the need for shaft seal packing is eliminated, and a completely airtight state can be reliably maintained permanently. Therefore, in addition to improving durability, it is possible to eliminate all the trouble of maintenance inspections, repairs and replacements of packings, etc., which were required for conventional products, and a significant reduction in the labor required for maintenance work can be achieved. In addition, in this device, the transmission main shaft 13 is supported rotatably in the retaining cylinder 11 at its inner end by a protruding shaft 14 drilled in the center of the closed wall of the inner end of the retaining cylinder 11, and at its other outer end by a cylindrical bearing member 15 similarly fitted and fixed to the open end of the retaining cylinder 11.
3 is supported at both ends. Therefore, the rotation of the main shaft 13 itself is performed smoothly without any wobble. In addition, the crank member 17 is integrally formed with a cylindrical portion 17a having magnetic poles N and S and a crank blade portion 17b having a protruding piece 17c, and is rotatably supported by a protruding shaft 18 protruding from the retaining cylinder 11, which is integral with the protruding shaft 14 supporting the main shaft 13. Therefore, the rotation of the main shaft 13 and the cylindrical portion 17a of the crank member 17 is performed accurately and smoothly around one axis without causing any relative positional deviation. In other words, the relative rotation is performed stably without any wobble. Therefore, the magnetic poles N and S of the main shaft 13 and the cylindrical portion 17a can be arranged as close as possible to each other.
This in turn increases the magnetic coupling between the two.
Therefore, the transmission main shaft 13 can be rotated reliably and synchronously with the crank member 17, thereby eliminating measurement errors, and the magnet coupling formed by the large-diameter portion 13a of the main shaft 13 and the cylindrical portion 17a of the crank member 17, which are positioned across the thin peripheral wall of the retaining tube 11, can be made extremely compact, thereby providing a counter transmission device that is convenient for installation in a gas meter.

[Brief explanation of drawings]

The drawings show an embodiment of this invention; Fig. 1 is a longitudinal sectional view of the entire gas meter without detailed illustrations of the structure of the meter, Fig. 2 is a longitudinal sectional view of the main parts of the counter transmission, and Fig. 3 The figure is a sectional view taken along the line of FIG. DESCRIPTION OF SYMBOLS 1...Case, 2...Measuring device, 5...Crank mechanism, 6...Counter mechanism, 10...Counter transmission, 11...Spindle holding cylinder, 12...Through hole, 1
3... Transmission main shaft, 14... Protruding shaft, 15... Bearing member, 16... Drive gear, 17... Crank member, 17a... Cylindrical portion, 17b... Crank wing portion, 18... Protruding shaft , 19... Drive pin, N, S...
...magnetic pole.

Claims (1)

[Scope of utility model registration request] A blind cylinder-shaped spindle holding cylinder 11 with one end open and the other end closed is inserted into a through hole 12 bored in the front cover of the case 1 containing the measuring instrument 2, with the open end facing the counter chamber side. The transmission main shaft 13 is fixed in an air-tight manner in an airtight state, and the transmission main shaft 13 is inserted into the holding cylinder 11 with the inner end thereof being connected to a protruding shaft 14 bored in the center of the closing wall at the inner end of the holding cylinder 11. , the other outer end is rotatably supported by a cylindrical bearing member 15 which is also fitted and fixed to the open end of the holding cylinder 11, and the transmission main shaft 1
A drive gear 16 that meshes with the input gear of the counter mechanism 6 is fixed to the outer end of the holding cylinder 11, and a crank member 17 is attached to the inner end of the holding cylinder 11.
The crank member 17 is a cylinder located outside the outer circumferential wall of the inner end of the holding cylinder 11 so as to face the large diameter portion 13a of the inner end of the transmission main shaft 13 through the wall. a crank blade portion 17b having a plurality of protrusions 17c integrally formed on the inner end of the cylindrical portion and extending radially on the outer circumferential surface;
The center part of the crank blade part 17b is loosely fitted and rotatably supported by a protruding shaft 18 protruding from the center of the inner end of the holding cylinder 11, and the radial protruding piece 17c
By bringing the drive pin 19 of the crank mechanism 5 of the measuring instrument 2 into contact with any one of the above, the drive pin 19 is driven to rotationally drive the main shaft 13. A plurality of magnetic poles N, S with different poles facing each other are provided on the outer circumferential surface of the inner end and the inner circumferential surface of the cylindrical portion 17a of the crank member 17.
A counter transmission device for a gas meter, characterized in that the counter transmission device is formed by: