JP2010145173A - Gas meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas meter including a rotating shaft reducing amount of grease discharged when integrating the rotating shaft into a rotary bearing or a bush. <P>SOLUTION: In this gas meter, a reciprocation motion of a metering film is converted into a rotation motion, and the rotation motion is transmitted to a digit wheel by a rotating shaft unit and displayed as a flow rate pointer value. The rotating shaft unit includes: the rotating shaft whose tip has an angle of 30-60° from the shaft center, and whose tip has a tapered shape having an R-shape with a radius of 0.5 mm, for transmitting the rotation motion; the rotary bearing for holding the rotating shaft rotatably; the bush wherein grease for keeping airtightly is applied onto the inside; and a rotating shaft gear for transmitting rotation of the rotating shaft to the digit wheel. The rotating shaft unit is fixed to a bulkhead for separating a gas chamber from its outside by the rotary bearing, and transmits the rotation motion to the digit wheel by the rotating shaft gear. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas meter, and more particularly to a rotating shaft for transmitting rotational motion to a numeral wheel to display the amount of gas used.

The membrane gas meter is provided with a metering membrane that reciprocates by the gas flowing in from the gas chamber. The reciprocating motion of the metering membrane is converted into a rotational motion by a crank mechanism, and this rotational motion is transmitted to the rotating shaft. A rotary shaft is pulled out from a bearing hole provided in a partition wall between the gas chamber and the gear, and the number wheel is driven by a gear provided at the tip of the rotary shaft. The amount of gas used can be understood by looking at the display of the numeral wheel (Patent Documents 1 and 2).
Registered Utility Model No. 2515129 Registered Utility Model No. 2578477

In the above-mentioned membrane gas meter, the rotational movement of the rotary shaft (horizontal axis) must be transmitted to the number wheel as smoothly as possible, and there should be no gas leakage.
For this purpose, the clearance between the rotating shaft for transmitting from the gas chamber to the numeral wheel and the bearing hole thereof is made small, grease is applied, and a bush is put on the rotating shaft.

  Here, the grease has a function of smooth rotation and airtightness. If the amount of grease is less than a prescribed amount, not only the rotation is not transmitted smoothly, but also gas leakage may occur.

When assembling the rotary shaft to the bearing or bush, apply grease to the inside of the bush, then fit it into the bearing, and finally push the rotary shaft into the bearing or bush and incorporate it.
Here, most of the tip of the rotary shaft used in the conventional gas meter is a flat surface, and the grease is pushed at the tip of the rotary shaft, so that less grease is filled in the bush. There was a problem.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas meter having a rotating shaft that reduces the amount of grease discharged when the rotating shaft is incorporated in a bearing or bush. .

  In order to achieve the above object, a gas meter according to the present invention converts a reciprocating motion of a measurement membrane into a rotational motion, and transmits the rotational motion to a number wheel by a rotary shaft unit to display it as a flow indicator value. The rotary shaft unit includes a rotary shaft that has a tapered tip and transmits the rotary motion, a rotary bearing that rotatably holds the rotary shaft, and a bush that is internally coated with grease for airtightly holding the rotary shaft. The rotating shaft gear is configured to transmit the rotation of the rotating shaft to the number wheel, and is fixed to a partition wall separating the gas chamber from the outside by the rotating bearing, and the rotating motion is transmitted to the number wheel by the rotating shaft gear.

The shape of the tip of the rotating shaft is preferably any one of the following shapes.
(1) The taper shape at the tip of the rotating shaft has an angle of 30 ° to 60 ° from the shaft center, and the tip has an R shape with a radius of 0.5 mm.
(2) In addition to the shape of (1), there is a cut from the front end to the rear end of the rotating shaft.
(3) In addition to the shape of (1), a spiral groove is formed on the side surface of the rotating shaft from the front end to the rear end.

According to the present invention, the grease filled in the bush is difficult to be pushed out by the tip of the rotating shaft, and a specified amount of grease can stay in the bush, thereby preventing smooth rotation of the rotating shaft and gas leakage. Is achieved.
Further, by making the shape of the tip of the rotating shaft into an R shape which is not an acute angle, it becomes safe in handling the parts.
In addition, by cutting the tip of the rotating shaft and engraving a spiral groove on the wall of the rotating shaft, the grease is less pushed out and smooth rotation of the rotating shaft and prevention of gas leakage are achieved. .

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
In the present embodiment, a membrane gas meter is described as an object, but any gas meter having a rotating shaft that is rotatable through a wall portion that separates the gas chamber and the outside can be applied.

  As shown in FIG. 1, the membrane gas meter has a casing C composed of an upper case 2 constituting the upper part and a main body case 3 constituting the lower part. The upper case 2 has a gas supply port 6 and a gas. A display surface provided outside the casing C, which is provided with a discharge port 7 and connected in the middle of a gas supply pipe for supplying gas to a gas demand destination such as a house to measure the flow rate of the gas flowing through the gas supply pipe 1 is configured to display the measured gas flow rate.

  By reciprocating the measuring film formed on the main body case 3, the gas flowing in from the gas supply port 6 is discharged to the gas discharge port 7, and this reciprocating motion is transmitted to the crank mechanism to be converted into rotational motion. .

  This rotational motion is caused by rotating the rotating shaft (horizontal shaft), and the gear train mechanism of the number wheel is driven by the gear provided at the tip of the rotating shaft. It is shown on the display surface 1.

2A and 2B are views showing the periphery of the rotating shaft provided in the upper case 2, wherein FIG. 2A is a perspective view of the upper case 2, FIG. 2B is a front view of the upper case 2, and FIG. Sectional drawing in the AA line of is represented.
The rotary shaft unit 4 is provided so as to pass through a partition wall 22 that separates a gas chamber 21 filled with gas and a counter chamber 23 with a numeral wheel, and performs rotational movement of the crank mechanism without causing gas leakage. It is transmitted to the gear mechanism of the number wheel.

  As shown in FIG. 3, the rotary shaft unit 4 includes a rotary shaft 41, a bush 42, a rotary shaft packing 43, a rotary bearing 44, and a rotary shaft gear 45. And the handle 47 are integrally provided. When the handle 47 is pushed by the rotational movement from the crank mechanism, the rotary shaft 41 rotates.

  As shown in FIG. 4, the rotating shaft unit 4 is assembled by injecting grease into the bushing 42, attaching the bushing 42 to the rotating bearing 44, and then fitting the rotating shaft packing 43 into the rotating bearing 44. After being assembled by screwing into the second partition wall 22, the rotating shaft 41 is inserted, and finally, the rotating shaft gear 45 is fixed by press-fitting the tip of the rotating shaft 41.

  When the rotary shaft 41 is inserted into the bush 42, the tip 411 of the conventional rotary shaft 41 as shown in FIG. 8 is a flat portion, so that the grease 5 is placed inside the bush 42 as shown in FIG. If it is filled, the grease 5 may be pushed out of the rotary bearing 44 to the outside as shown in FIG.

  On the other hand, in the present invention, the grease is not easily pushed out by making the rotating shaft have any one of the following shapes.

(1) The tip of the rotating shaft is tapered.
As shown in FIG. 5, it is preferable that the tip 411 of the rotating shaft 41 has a tapered shape with an angle within 30 ° to 60 ° from the center of the shaft, and the tip has an R shape with a radius of about 0.5 mm.

As a result, since the tip is not a flat portion, the grease filled in the bush 42 is difficult to be pushed out, and a specified amount of grease stays in the bush, so that smooth rotation of the rotating shaft and prevention of gas leakage are achieved. The
In addition, since the tip is not an acute angle, the safety of handling parts is improved.

(2) The tip of the rotating shaft is tapered and cut.
As shown in FIG. 6, by inserting a notch 412 from the front end to the rear end of the rotating shaft 41, when the rotating shaft 41 is inserted into the bush 42, the grease filled in the bush 42 is pushed out. And can stay inside the rotary bearing 44.

(3) The tip of the rotating shaft is tapered, and a spiral groove is formed on the side surface of the rotating shaft.
As shown in FIG. 7, a spiral groove 413 is formed on the side surface 414 from the front end to the rear end of the rotating shaft 41. The depth of the spiral groove 413 needs to be deep enough not to reduce the strength of the shaft, and a depth of about 0.5 mm is appropriate for a shaft diameter of 3 mm. The groove width is preferably about 1 mm with respect to a depth of 0.5 mm.

  When the rotating shaft 41 is assembled to the rotating shaft unit 4, the grease that is about to be pushed out is inserted along the groove 413 by inserting the rotating shaft 41 while rotating the tip of the rotating shaft 41 in the direction in which the spiral advances. Since it can be pushed back in the direction, the grease pushed out by the rotating shaft 41 is further reduced.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and corrections can be made without departing from the scope of the present invention.

It is a perspective view of the membrane type gas meter concerning an embodiment. They are a perspective view (A), a front view (B), and a sectional view (C) of the upper case. It is a figure which shows the structure of a rotating shaft unit. It is a figure when a rotating shaft unit is attached to a partition. It is a figure which shows the shape of a rotating shaft. It is a figure which shows the other shape of a rotating shaft. It is a figure which shows the other shape of a rotating shaft. It is a figure which shows the shape of the conventional rotating shaft. It is a figure which shows a mode that grease is discharged | emitted.

Explanation of symbols

C ... casing, 1 ... display surface, 2 ... upper case, 21 ... gas chamber, 22 ... partition wall, 23 ... counter chamber, 3 ... main body case, 6 ... gas supply port, 7 ... gas discharge port, 4 ... rotating shaft unit , 41 ... Rotating shaft (horizontal axis), 411 ... Tip of rotating shaft, 412 ... Notch of rotating shaft, 413 ... Groove in side of rotating shaft, 414 ... Side surface of rotating shaft, 42 ... Bush, 43 ... Rotating shaft Packing 44... Rotating bearing 45. Rotary shaft gear 46. Arm 47. Handle 5 Grease

Claims (4)

  In the gas meter that converts the reciprocating motion of the measurement membrane into a rotational motion, and transmits this rotational motion to the numeral wheel by the rotational shaft unit and displays it as a flow rate guide value, the rotational shaft unit has a tapered tip and performs the rotational motion. From a rotating shaft that transmits, a rotating bearing that rotatably holds the rotating shaft, a bush that is internally coated with grease for holding airtightly, and a rotating shaft gear that transmits rotation of the rotating shaft to the numeral wheel The gas meter is fixed to a partition wall that separates the gas chamber from the outside by the rotary bearing, and the rotary motion is transmitted to the numeral wheel by the rotary shaft gear.   2. The gas meter according to claim 1, wherein the tip of the rotating shaft has a tapered shape having an angle of 30 ° to 60 ° with respect to the center of the shaft, and the tip has an R shape having a radius of 0.5 mm. .   The gas meter according to claim 2, wherein there is a cut from a front end to a rear end of the rotating shaft.   The gas meter according to claim 2, wherein a spiral groove is formed on a side surface of the rotating shaft from a front end to a rear end.