JPH09329111A - Shaft connecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely connect a valve stem to a driving shaft. SOLUTION: This shaft connecting device is so constituted that a key 9 is fitted into key ways 6 and 7 formed on the outer circumferential face of a valve stem 3 and a driving shaft 4 which are concentrically arranged, a coupling 5 is externally fitted with the valve stem 3 and the driving shaft 4, a key way 8 formed on the inner circumferential face of the coupling 5 is fitted into the key 9 so that the valve stem 3 is integrally connected with the driving shaft 4. In this case, a tapered inclination toward the centers of the valve stem 3 and the driving shaft 4 is formed on the side of an inner key part 9a to be fitted into the key ways 6 and 7 of the key 9, a tapered inclination toward the outside of the coupling is formed on the side of an outer key part 9b to be fitted into the key way 8 of the key 9, and a pair of flanges 5b and 5c projected with the key way 8 between them are fastened to the coupling 5 with a bolt nut 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft connecting device for integrally connecting a valve shaft of a butterfly valve and a drive shaft, for example.

[0002]

2. Description of the Related Art Conventionally, an example of a butterfly valve is shown in FIGS. This is because a valve body 2 is rotatably disposed in a valve box 1 via a valve rod 3, a drive shaft 4 is concentrically arranged so as to face the valve rod 3, and a small-diameter upper end of the valve rod 3 is arranged. The key 9 is fitted into the key grooves 6 and 7 formed in the portion 3a and the small-diameter lower end portion 4a of the drive shaft 4, the coupling 5 is fitted onto the both portions 3a and 4a, and the inner circumference of the coupling 5 is formed. By fitting the key groove 8 formed on the surface into the key 9, the valve rod 3 and the drive shaft 4 are integrally connected.

[0003]

SUMMARY OF THE INVENTION In the above conventional configuration,
Since the key 9 is simply fitted into the key groove formed in the valve rod 3, the drive shaft 4, and the coupling 5, a clearance may be generated between the key 9 and each of the key grooves 6 to 8. Due to the clearance, the valve rod 3 is not reliably connected to the drive shaft 4, and there is a possibility that the valve element 2 may swing and cause a water hammer when water is passed.

In view of the above problems, it is an object of the present invention to provide a shaft connecting device capable of surely connecting shafts.

[0005]

In order to achieve the above object, the invention according to claim 1 fits a key into a key groove formed on the outer peripheral surface of two concentrically arranged shafts, and the both shafts In the shaft coupling device, the coupling is fitted onto the outer periphery of the coupling, and the key groove formed on the inner peripheral surface of the coupling is fitted into the key to integrally couple the both shafts. Is formed on the side surface of the inner key portion that fits into the shaft side key groove of the outer key portion, and the side surface of the outer key portion that fits into the coupling side key groove of the key. In addition, a tapered slope is formed toward the outside of the coupling, and a space adjusting tool for adjusting the space between the coupling-side key grooves is provided.

Here, the butterfly valve will be described as an example. A key is fitted in a key groove formed in the valve rod (shaft) and the drive shaft (shaft) and externally fitted in the valve rod and the drive shaft. The key groove formed in the coupling may be fitted into the key, and the gap between the coupling side key grooves may be narrowed by the gap adjusting tool. Accordingly, the key can be pushed into the key groove of the valve rod and the drive shaft to integrally connect the drive shaft and the valve rod.

In this case, by narrowing the gap between the coupling-side key grooves by the gap adjusting tool, the side surface of the outer key portion having the slope is pressed, and the inner key portion is pushed into the shaft-side key groove. Since the inclined side surface of the inner key portion is pressed against the side surface of the shaft side key groove, there is no clearance between the key and each key groove. Therefore, for example, in the case of a butterfly valve, the valve rod is reliably connected to the drive shaft, and there is no possibility that the valve body will oscillate and water hammer will occur during water passage.

According to a second aspect of the present invention, in the first aspect of the invention, the side surface of each key groove facing the side surface of each key portion where the slope is formed has an inclination angle substantially the same as the inclination angle of each key portion. It is characterized by the formation of a gradient.

According to the above structure, the sloped side surface of each key groove can be brought into surface contact with the sloped side surface of each key portion so that no clearance is generated between them. For example, in the case of a butterfly valve, the valve rod is more reliably connected to the drive shaft, and there is no risk of causing a water hammer when the valve body is swung during water passage.

[0010] The third aspect of the present invention is the first or second aspect.
In the invention described above, the space adjusting tool is composed of bolts and nuts for tightening a pair of flanges projecting at predetermined intervals with a key groove sandwiched in the coupling.

According to the above construction, the gap between the coupling side key grooves can be easily adjusted by adjusting the tightening force of the bolts and nuts.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows the valve stem (shaft) of a butterfly valve.
3 shows a state in which a drive shaft (shaft) 3 and a drive shaft (shaft) 4 are connected by a shaft connecting device according to an embodiment of the present invention, wherein the shaft connecting device is a concentrically arranged valve rod 3 and drive shaft. The key 9 is fitted into the key grooves 6 and 7 formed in both the small diameter upper end portions 3a and 4a of 4, and the coupling 5 is fitted onto the both portions 3a and 4a, and the key groove 8 of the coupling 5 is formed into A space adjusting tool 10 is provided on the coupling 5 so as to be fitted to the key 9. Since the configuration other than the above is almost the same as that of the conventional example shown in FIGS. 5 and 6, the same reference numerals are given to the same portions and the description thereof will be omitted.

As shown in FIGS. 2 to 4, the coupling 5 includes a coupling body 5a having a split cylindrical shape, and a pair of flanges 5b and 5c integrally projecting from both side edges of the coupling body 5a. And both flanges 5b, 5c
The key groove 8 is formed therebetween.

The space adjusting tool 10 includes two flanges 5b,
A bolt 10a inserted through a through hole 11 formed through 5c;
It is composed of a nut 10b that is screwed into the bolt 10a, and by tightening the nut 10b, the interval H of the coupling side key groove 8 can be adjusted.

The key 9 is composed of an inner key portion 9a fitted into the shaft side key grooves 6 and 7, and an outer key portion 9b fitted into the coupling side key groove 8, and one side surface of the inner key portion 9a. A tapered slope 11 is formed toward the center of the valve rod 3 and the drive shaft 4 at a predetermined inclination angle α, and the coupling 5 is formed on one side surface of the outer key portion 9b.
A tapered slope 12 is formed at a predetermined inclination angle β toward the outside.

In the above structure, the key 9 is fitted in the key grooves 6, 7 formed in the valve rod 3 and the drive shaft 4, and the small diameter upper end portion 3a of the valve rod 3 and the small diameter lower end portion 4a of the drive shaft 4 are externally fitted. The key groove 8 of the coupling 5 thus fitted is fitted into the key 9, and the bolt 1 is inserted into the through holes 11 of both flanges 5b and 5c.
0a is inserted and the nut 10b is attached to the bolt 10a.
It suffices to screw and tighten to narrow the gap H between the coupling-side key grooves 8. By this, one flange 5c
The side surface of the outer key portion 9b that forms the slope 12 is pressed by the inner key portion 9a into the key grooves 6 and 7 of the valve rod 3 and the drive shaft 4, and the slope 11 of the inner key portion 9a is pressed.
Since the side surface forming the key is pressed against the side surfaces of the key grooves 6 and 7, there is no clearance between the key 9 and each of the key grooves 6 to 8, and the valve rod 3 is connected to the drive shaft 4. There is no risk of rocking the valve body 2 and causing a water hammer during water passage.

The slopes 11 and 12 of the respective key portions 9a and 9b
On the side surfaces of the respective key grooves 6 to 8 facing the side surface on which is formed the slopes 13 and 14 having the inclination angles α and β substantially the same as the slopes 11 and 12 of the key portions 9a and 9b, respectively.

According to the above structure, the side surfaces of the key portions 9a and 9b having the slopes 11 and 12 are brought into surface contact with the side surfaces of the key grooves 6 to 8 having the slopes 13 and 14 between them. Since the clearance can be prevented, the valve rod 3 is more reliably connected to the drive shaft 4, and there is no possibility that the valve body 2 is swung and water hammer occurs when water is passed.

In the above embodiment, the slopes 11 to 14 are formed only on one side surface of each of the key grooves 6 to 8 and each of the key portions 9a and 9b. However, the present invention is not limited to this, and each of the key grooves 6 to. 8 and the slopes 11 to 1 on both side surfaces of each key portion 9a, 9b
4 may be formed.

Although the butterfly valve has been described as an example, the invention is not limited to this but can be applied to the case where concentrically arranged shafts of various devices are connected.

[0021]

According to the first aspect of the present invention, the gap between the coupling-side key grooves is narrowed by the gap adjuster, so that the sloped side surface of the outer key portion is pressed and the inner key portion is rotated. Since the side surface of the inner key portion that is pushed into the side key groove and has the slope is pressed against the side surface of the shaft side key groove, there is no clearance between the key and each key groove. Therefore, for example, in the case of a butterfly valve, the valve rod is reliably connected to the drive shaft, and there is no possibility that the valve body will oscillate and water hammer will occur during water passage.

According to the second aspect of the present invention, the sloped side surface of each key portion is brought into surface contact with the sloped side surface of each key groove so that no clearance is generated therebetween. Therefore, in the case of a butterfly valve, for example, the valve rod is more reliably connected to the drive shaft, and there is no risk of rocking the valve element when passing water to cause a water hammer.

According to the third aspect of the present invention, by adjusting the tightening force of the bolts and nuts, it is possible to easily adjust the distance between the coupling-side key grooves.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a butterfly valve using a shaft connecting device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the coaxial coupling device.

FIG. 3 is a view as viewed in the direction of arrows AA in FIG. 2;

FIG. 4 is an exploded perspective view of the main part.

FIG. 5 is a cross-sectional view showing a conventional example.

FIG. 6 is a view taken in the direction of arrows BB in FIG. 5;

[Explanation of symbols]

 3 Valve Rod (Shaft) 4 Drive Shaft (Shaft) 5 Coupling 5b, 5c Coupling Flange 6-8 Keyway 9 Key 9a Inner Key Part of Key 9b Outer Key Part of Key 10 Spacing Adjuster 10a Bolt 10b Nut 11 Inner key slope 12 Outer key slope 13,14 Key groove slope α, β Inclination angle

Claims (3)

[Claims] 1. A key is fitted into a key groove formed on the outer peripheral surfaces of two concentrically arranged shafts, a coupling is externally fitted on both shafts, and a key is formed on the inner peripheral surface of the coupling. In a shaft connecting device configured to integrally connect the both shafts by fitting a key groove into the key,
On the side surface of the inner key portion that fits in the shaft side key groove of the key,
A tapered slope is formed toward the center of the shaft, and a tapered side toward the outside of the coupling is formed on the side surface of the outer key portion that fits into the key groove on the coupling side of the key. A shaft coupling device, wherein a gradient is formed, and a gap adjusting tool for adjusting the gap of the coupling-side key groove is provided. 2. A slope having substantially the same inclination angle as the slope of each key portion is formed on a side surface of each key groove opposite to a side surface of each key portion where the slope is formed. The shaft connecting device described. 3. The shaft according to claim 1 or 2, wherein the space adjusting tool comprises a bolt and a nut for tightening a pair of flanges protruding from the coupling with a key groove interposed therebetween at a predetermined interval. Coupling device.