JPH10169724A - Reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively prevent unexpected opening and closing of a valve element due to the fluid pressure of fluid passing through the inside of a valve casing by improving the efficiency of a reduction gear to reduce controlling force for opening and closing the valve element, and allowing the reduction gear to have a self-locking function. SOLUTION: The reduction gear is provided with a worm 5 on the driving shaft 4 side, and a fan-type turning plate 9 mounted to the driven shaft (valve rod) 6 crossing the driving shaft 4 at right angles so that it can rotate simultaneously with the driven shaft. Then, plural cone rollers 10, 10... sequentially engaging the screw gear teeth 5A of the worm 5 in rolling contact, are rotatably mounted on the shafts of roller shafts 11 at specified intervals in the circumferential direction on the outer peripheral edge part of the turning plate 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a speed reducer, and more particularly to a speed reducer suitable for opening and closing a valve element such as a butterfly valve, a ball valve, or an eccentric structure valve.

[0002]

2. Description of the Related Art Conventionally, for example, in a manual butterfly valve shown in FIG.
The speed reducer 3 is used to open and close the. The speed reducer 3 is disposed outside the valve box 1 and has a worm 5 on the drive shaft 4 side.
And a worm gear 7 attached to a driven shaft (valve rod) 6 orthogonal to the drive shaft 4 so as to be able to rotate simultaneously. Therefore, by manually rotating the handle 8 attached to the drive shaft 4 in the forward or reverse direction, the worm gear 7 and the valve rod 6 are rotated in the forward or reverse direction at a large reduction ratio, thereby allowing the valve body to rotate. 2 can be opened and closed.

However, in the speed reducer 3 composed of a combination of the worm 5 and the worm gear 7, the screw teeth 5A of the worm 5 and the plurality of teeth 7 of the worm gear 7 are provided.
Since A and 7A are successively meshed by sliding contact, the sliding resistance of the meshing portion is large, and the efficiency is poor at about 0.3 to 0.4. Therefore, a relatively large operation force is required to open and close the valve body 2. For this reason, it is conceivable to configure the reduction gear 3 by combining the spur gear and the bevel gear, and improve the efficiency to about 0.9. However, since the speed reducer 3 configured by a combination of the spur gear and the bevel gear does not have a self-locking function, the valve element 2 is unintentionally opened and closed by the fluid pressure passing through the valve box 1. Will be. Therefore, it cannot be used for a butterfly valve, a ball valve, an eccentric structure valve, or the like.

[0004]

That is, in a conventional speed reducer constituted by a combination of a worm and a worm gear, the screw teeth of the worm and a plurality of teeth of the worm gear sequentially mesh with each other in sliding contact. Therefore, since the sliding resistance of the meshing portion is large and the efficiency is low, there is a disadvantage that a relatively large operation force is required to open and close the valve body. On the other hand, it is conceivable to improve the efficiency by configuring a reduction gear by combining a spur gear and a bevel gear. However, since this type of speed reducer does not have a self-locking function, the valve body is unintentionally opened and closed by the fluid pressure passing through the valve box. Can not be used. Therefore, the present invention can improve the efficiency and reduce the operation force for opening and closing the valve body, and by having a self-locking function, the unintended opening and closing of the valve body due to the fluid pressure passing through the inside of the valve box. It is an object of the present invention to provide a speed reducer that can surely prevent the reduction.

[0005]

In order to achieve the above object, the present invention comprises a worm on a drive shaft side and a rotating plate mounted on a driven shaft orthogonal to the drive shaft so as to be simultaneously rotatable. The rotary plate is provided with a plurality of rollers having conical portions that are sequentially engaged with the threaded teeth of the worm at predetermined intervals in the circumferential direction by rolling contact.

According to the present invention, the conical portions of the plurality of rollers are successively meshed with the threaded teeth of the worm by rolling contact, so that the resistance of the meshed portion is reduced and the efficiency can be improved. Further, a self-locking function that does not transmit the rotation of the driven shaft and the rotating plate to the worm and the drive shaft can be exhibited.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a front view showing a meshing state between a worm screw tooth and a plurality of conical rollers. In addition, valve box,
The valve body and the like are the same as those in the conventional example shown in FIG. 1 and 2, the reduction gear 3
Is disposed outside the valve box 1 and includes a worm 5 on the drive shaft 4 side and a fan-shaped rotating plate 9 attached to a driven shaft (valve rod) 6 orthogonal to the drive shaft 4 so as to be simultaneously rotatable. Have.
A plurality of roller shafts 11 are attached to the outer peripheral edge of the rotating plate 9 at a predetermined interval in the circumferential direction, and each of the roller shafts 11 is sequentially meshed with the screw teeth 5A of the worm 5 by rolling contact. A conical roller (more specifically, a downwardly-truncated conical roller) 10 is rotatably mounted around a roller shaft 11. Therefore, by manually rotating the handle 8 attached to the drive shaft 4 in the forward or reverse direction, the rotating plate 9 and the valve stem 6 in FIG. 3 are rotated in the forward or reverse direction at a large reduction ratio. Thus, the valve body 2 can be opened and closed.

According to the speed reducer 3 according to the present invention, the plurality of conical rollers 1 are brought into rolling contact with the screw teeth 5 A of the worm 5.
Since 0, 10... Sequentially mesh, the resistance of the meshing portion is reduced, the efficiency is improved to about 0.9, and the operating force for opening and closing the valve body 2 can be reduced. In the manual type in which the drive shaft 4 is manually rotated via the handle 8, the operating force is reduced to about 1/3 to 1/2. In the electric type in which the drive shaft 4 is rotated by an electric motor, the capacity of the electric motor is reduced. About 1/3 ~
It has been confirmed that it can be reduced to half.

Further, similarly to the conventional speed reducer 3 constituted by a combination of a worm 5 and a worm gear 7, a self-locking function for preventing the rotation of the driven shaft 6 from being transmitted to the worm 5 and the drive shaft 4 is exhibited. Therefore, unintended opening and closing of the valve element 2 due to fluid pressure passing through the inside of the valve box 1 can be reliably prevented. Therefore, it can be used for a butterfly valve, a ball valve, an eccentric structure valve, or the like.

In the above embodiment, a plurality of roller shafts 1 are provided on the outer peripheral edge of the rotating plate 9 at predetermined intervals in the circumferential direction.
1 and a conical roller 10 which is in contact with each of the roller shafts 11 in a rolling contact with the screw teeth 5A of the worm 5 is rotatably mounted around the shaft. A deformed roller having a conical portion or a truncated cone formed at the tip of a cylindrical roller having a large outer diameter is provided, and the deformed roller is rotatably mounted on each of a plurality of roller shafts 11 so as to be rotatable around the axis. The conical portion or the truncated conical portion may be sequentially engaged with the screw teeth 5A of the worm 5 by rolling contact.

[0011]

As described above, according to the present invention, since the conical portions of a plurality of rollers are sequentially meshed by rolling contact with the screw teeth of the worm, the resistance of the meshing portion is reduced, the efficiency is improved, and the valve is improved. The operating force for opening and closing the body can be reduced. That is, in the manual type in which the drive shaft is rotated manually, the operating force is reduced to about 1/3 to 1/2, and in the electric type in which the drive shaft is rotated by the electric motor, the capacity of the electric motor is reduced to about 1/3 to 1/1/2.
2 can be reduced. In addition, since the self-locking function of preventing the rotation of the driven shaft from being transmitted to the rotation plate and the worm and the drive shaft can be exhibited, it can be used for a butterfly valve, a ball valve, an eccentric structure valve, and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a front view showing a meshing state between a worm screw tooth and a plurality of conical rollers;

FIG. 3 is a perspective view showing a partial cross section of a conventional speed reducer applied to a butterfly valve.

[Explanation of symbols]

 Reference Signs List 3 speed reducer 4 drive shaft 5 worm 5A worm screw tooth 9 rotating plate 10 conical roller (roller with conical portion)

Claims (1)

[Claims] 1. A worm on a drive shaft side, and a rotating plate attached to a driven shaft orthogonal to the drive shaft so as to be simultaneously rotatable, the rotating plate having a predetermined interval in a circumferential direction. A plurality of rollers each having a conical portion that is successively engaged with the threaded teeth of the worm by rolling contact.