JP2565458Y2 - Gate valve actuator - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator in which the function of a valve is not affected even if the valve shaft expands and contracts due to fluctuations in the temperature around the gate valve.

[0002]

2. Description of the Related Art FIG. 2 shows a main part of a conventional gate valve.
A vertically long guide groove (4) cut at the side of a vertical valve shaft (3) fixed at its lower end to the valve body (1) and penetrating through the valve box (2).
The, you have set-digit detent (5) is fitted to the valve box (2)
Ri, the valve shaft (3), are allowed lifting the actuator <br/> data provided at the upper end of the valve box (2) (A), to open and close the valve body (1).

[0003] are screwed stem nut (6) on the top of the valve shaft (3), stem nut (6), the upper and lower Beyaringu (7)
It is clamped by (7) and is supported by the valve box (2) so that it cannot rotate freely.

A worm wheel is provided on the stem nut (6).
(8) is a solid wear, worm which meshes with the worm wheel (8) (9), made me rotated in both directions by a motor (10)
You. The valve element (1) rises with the valve shaft (3) by the rotation of the motor (10) to open and close the gate valve.

[0005]

[Devised Problems to be Solved] valve shaft of <br/> length dimension of the gate valve (3) Since the expansion and contraction due to changes in ambient temperature, in a conventional gate valve, at a nighttime low temperature valve box
(3) shrinks , and the closed valve element opens slightly during hot daytime.
There is.

[0006] The valve closed at night during cold is daytime when high temperatures, the valve shaft (3) is extended actuator
The member (A) may be damaged. The present invention has been made to solve these problems.

[0007]

According to the present invention, there is provided a gate valve.
Threaded stem nut Nagasun to the valve shaft facing the vertical direction of
If then, in place of the stem nut, rotating by a suitable driving device
Worm wheel meshed with worm to be turned
Through a spline, fitted non-rotatably and slidably in the axial direction , and fitted to the upper end of the stem nut, a buffer cylinder that was slightly movable in the axial direction, and further into the valve box , The above- mentioned problem is solved by providing a compression spring that presses the buffer cylinder downward.

[0008]

When the valve shaft is slightly expanded or contracted due to temperature change when the valve body is at the upper or lower limit, the compression spring of the stem nut expands and contracts to cope with the movement of the buffer cylinder. , it is pressed in the direction to close the valve with a constantly Teki圧, or close the valve is open, to prevent the member from being damaged.

The worm wheel and the stem nut are
Because the line is connected, the valve shaft expands and contracts due to temperature changes
The worm wheel does not move up and down,
Damage the worm and worm wheel.
No.

[0010]

FIG. 1 shows an embodiment of the present invention, in which the same members as those of the conventional actuator (A) described above are provided.
The same reference numerals are given and the description is omitted. Valve shaft (3)
Is the actuator of the present invention installed on the top of the valve box (2).
(B) moves up and down to open and close the valve body .

[0011] valve shaft (3) is either than the conventional ones described above
Become length dimensions of the stem nut (11) is screwed, stem nut
At (11), a worm wheel (12) is connected via a spline (13) .
And it is mutually unrotatable vertically movably fitted.

[0012] Warm you are meshed with the worm wheel (12) (14) rotates in both directions by a motor (not shown)
Can be The worm wheel (12) is supported by the valve box (2) by a bearing (15) so as not to move laterally.

[0013] The upper end of the stem nut (11), Beyaringu
The buffer cylinder (17) is fitted through (16) . Buffer tube (17)
A slight gap (18) is provided between the upper and lower ends of the valve body and the inward step of the valve box (2), and the shock-absorbing cylinder (17) can be slightly moved up and down.
It has become.

[0014] The outer step portion of the upper part of the buffer cylinder (17) and the valve box (2)
Between the inward step (19) provided at the upper end , a compression spring (20)
Is provided. When together with the worm wheel (12) stem nut (11) is rotated, the valve body with the valve shaft (3) (not shown) to lift, opening and closing the valve.

When the valve is located at the upper or lower limit
, When the valve shaft due to a temperature change (3) is expanded and contracted, the stem nut (11) is raised and lowered slightly the extent permitted by the gap (18) together with the shock absorbing cylinder (17). However, the worm wheel (12), since the stem nut (11) and is spline-coupled, lifting
I will not do it.

[0016] Thus, with the lift of the valve stem (3), even if the lift stem nut (11) is, Waugh a worm wheel (12)
Beam (14) never meshed relationship varying, can be without any trouble lifting the valve shaft (3), also the worm (14) and worm wheel (12) does not damage the member or the like.

Even if the valve shaft (3) is shortened, the valve shaft (3) is
Since the compression spring (20) pushes down the cushion via the buffer cylinder (17) and the stem nut (11), the closed valve does not leak.

[0018]

[Effects of the invention] (a) The stem nut that can be raised and lowered slightly
By the compression spring, it is always pressed downward through the buffer cylinder
The valve is at the upper or lower limit
, Even if the valve shaft expands and contracts slightly due to temperature changes,
Leaking from a valve that is
There is no damage to members such as gears.

(B) Worm wheel and stem nut
Are spline-coupled, the valve shaft is
The worm wheel does not move up and down even if
Damage to the worm and worm wheel
Not even.

[Brief description of the drawings]

FIG. 1 is a front view of the actuator according to the present invention, taken along a central longitudinal section.

FIG. 2 is a front view in the center longitudinal section of a conventional actuator.

[Explanation of symbols]

 (A) (B) Actuator (1) Valve body (2) Valve box (3) Valve shaft (4) Guide groove (5) Non-rotating (6) Stem nut (7) Bearing (8) Worm wheel (9) Worm (10) Motor (11) Stem nut (12) Worm wheel (13) Spline (14) Worm (15) (16) Bearing (17) Buffer cylinder (18) Clearance (19) Annular groove (20) Compression spring

Claims (1)

(57) [Scope of request for utility model registration] 1. A by screwing the stem nut Nagasun to the valve shaft facing the vertical direction of the gate valve, in place <br/> stem nut, a worm which is rotated by a suitable driving device engage
Turn the combined worm wheel through the spline
A buffer which is immovable and slidable in the axial direction , and is slightly movable in the axial direction on the upper end of the stem nut.
An actuator for a gate valve , wherein a compression spring that presses the buffer cylinder downward is provided in the valve box , the cylinder being fitted therein .