CONTROL VALVE FOR A PROCESS PLANT

Abstract

The invention relates to an actuator for a process plant, with a pneumatically operated actuating drive (4), which is connected to a valve housing (8) of a control valve via a yoke (10), and with a drive rod (16), a valve cone (20) actuated by the actuating drive (4) with a valve rod (18), and a rod connector (14), which connects the drive rod (16) and the valve rod (19) to one another for transmitting power, wherein the rod connector (14) is rotationally fixed to the yoke (10), on the one hand. The invention is characterized in that the rod connector (14) is non-rotatably connected to the valve rod (18), on the other hand.

Claims

1. Actuator for a process plant, having a pneumatically operated actuating drive (4) which is connected to a valve housing (8) via a yoke (10) and has a drive rod (16), a valve cone (20) which is actuated by the actuating drive (4) and has a valve rod (18), and a rod connector (14) which connects the drive rod (16) and the valve rod (18) to one another for force transmission, which rod connector (14) is non-rotatably fixed to the yoke (10), on the one hand, characterized in that said rod connector (14) is non-rotatably connected to the valve rod (18), on the other hand.

2. Actuator according to claim 1, characterized in that the yoke (10) is secured to the valve housing (8) by a positive fit.

3. Actuator according to claim 2, characterized in that the positive fit between the yoke (10) and the valve housing (8) has a ball/ball receptacle or pin/pin receptacle or feather keys or elevations and depressions between the yoke (10) and the valve housing (8).

4. Actuator according to claim 1, characterized in that the rod connector (14) is formed by two half-shells (30, 32) which are fastened to one another by bolts (34, 36, 38, 40, 42, 44), and that the rod connector (14) comprises a first connecting device (46) on the drive rod side and a second connecting device (48) on the valve rod side.

5. Actuator according to claim 4, characterized in that the connecting device (46) has a coupling head (50) on the drive end of the drive rod (16), which head (50) is embraced by the half shells (30, 32) via a corresponding groove bulge so that the rod connector (14) is non-rotatably mounted on the valve rod (18).

6. Actuator according to claim 4, characterized in that, on the drive end of the drive rod (16), the connecting device (48) comprises a bushing (52) formed by the half shells (30, 32) of the rod connector (14), in which bushing (52) a cylindrical shoulder (54) on the drive rod (16) is non-rotatably mounted.

7. Actuator according to claim 5, characterized in that, on the drive end of the drive rod (16), the connecting device (48) comprises a bushing (52) formed by the half shells (30, 32) of the rod connector (14), in which bushing (52) a cylindrical shoulder (54) on the drive rod (16) is non-rotatably mounted.

8. Actuator according to claim 1, characterized in that for non-rotatably connecting the rod connector (14) to the yoke (10), the yoke (10) has a guide device (56) along which the rod connector (14) is slidingly guided in an axially movable manner over the entire stroke range.

9. Actuator according to claim 8, characterized in that the guide device (56) has a guide rail (58) aligned on the yoke (10) in the direction of movement of the valve rod (18) and a guide carriage (60) guided on the guide rail (58) and integrally formed on the rod connector (14).

10. Actuator according to claim 9, characterized in that the guide carriage (60) has two legs (62, 64) which engage on both sides on the guide rail (58) via sliding layers (66, 68).

11. Actuator according to claim 1, characterized in that a pointer (70) is provided on the rod connector (14) and a marker (72) is provided on the yoke (10) so that the stroke of the valve body (20) can be read off.

12. Actuator according to claim 1, characterized in that the rod connector (14) comprises a mechanical stroke pick-up device which can be coupled to a positioner or a stroke indicator in order to output a control signal which is proportional to the stroke value.

Description

[0017] Throughout the description, the claims and the drawings, those terms and associated reference characters are used as are indicated in the List of Reference Characters which follows below. In the drawings

[0018] FIG. 1 is a sectional view of an actuator having a rod connector, in accordance with the invention;

[0019] FIG. 2 is a lateral view of the part of the actuator that has the rod connector, in accordance with the invention;

[0020] FIG. 3 is a sectional view taken along line A-A of FIG. 2;

[0021] FIG. 4 is a sectional view taken along line B-B of FIG. 2.

[0022] FIG. 1 is a sectional view of an actuator 2 according to the invention. The actuator 2 essentially comprises a pneumatic actuating drive 4, a control valve body 6 with a valve housing 8, a yoke 10 arranged between the actuating drive 4 and the valve housing 8 or a cover 12 of the valve housing 8 and fixed to the valve housing 8 by positive locking, as well as a rod connector 14 through which the actuating movement is transmitted from the pneumatic actuating drive 4 to the control valve body 6. A drive rod 16 of the actuating drive 4 extends out of the actuating drive 4.

[0023] The control valve body 6 is equipped with a valve rod 18 that is axially aligned vertically to the drive rod 16. A valve cone 20 is arranged at the end of the valve rod 18 that faces away from the actuating drive 4. The valve cone 20 is used to open and/or close an opening of a valve seat 22 in order to allow or to block a flow through the control valve body 6 from an inlet area 24 to an outlet area 26.

[0024] To guide the valve rod 18, a guide sleeve 28 on the valve seat side and a seal packing (not shown) are provided. To connect the valve-side end of the drive rod 16 and the drive-side end of the valve rod 18, the rod connector 14 is provided which is implemented by two half-shells 30, 32. The two half shells 30, 32 are attached to each other by means of bolts 34, 36, 38, 40, 42, 44.

[0025] The rod connector 14, which on the one hand is non-rotatably connected to the yoke 10 and on the other hand is firmly connected to the valve rod 18, has a first connection device 46 on the drive rod side and a second connection device 48 on the valve rod side. The connection device 46 on the drive end of the drive rod 16 comprises a coupling head 50 which the half-shells 30, 32 embrace by means of a corresponding groove bulge, so that the rod connector 14 is non-rotatably fastened to the valve rod 18.

[0026] The connection device 48 on the valve rod end of the drive rod 16 comprises a bushing 52 formed by the half shells 30, 32 of the rod connector 14 and a cylindrical extension 54 on the drive rod 16 which is received in the bushing 52 in a rotationally fixed manner.

[0027] The positive connection between yoke 10 and valve housing 8 may have a ball/ball receptacle or pin/pin receptacle or feather keys or elevations and depressions between the yoke and the valve housing, with a ball/ball receptacle 55 being shown in the view of FIG. 2.

[0028] The non-rotatable connection of the rod connector 14 with the yoke 10 consists of the yoke 10 having a guide device 56 along which the rod connector 14 is slidingly guided in an axially movable manner over the entire stroke range of the valve rod 18. The guide device 56 comprises a guide rail 58 aligned on the yoke 10 in the direction of movement of the valve rod 18 and a guide carriage 60 guided on the guide rail 58 and integrally formed on the rod connector 14. The guide carriage 60 has two legs 62, 64 which engage the guide rail 58 on both sides via sliding layers 66, 68.

[0029] The rod connector 14 may have a pointer 70, and a marking 72 may be provided on the yoke 10, so that the stroke of the valve cone 20 can be read off. The rod connector 14 may also have a mechanical stroke pick-up device which can be coupled to a positioner or to a stroke indicator to output a control signal proportional to the stroke value.

[0030] The invention is not limited to the embodiment shown. The seal arrangement may for instance be arranged at other locations of actuators, for example between the valve seat and the valve housing.

LIST OF REFERENCE CHARACTERS

[0031] 2 actuator

[0032] 4 actuating drive

[0033] 6 control valve body

[0034] 8 valve housing

[0035] 10 yoke

[0036] 12 cover

[0037] 14 rod connector

[0038] 16 drive rod

[0039] 18 valve rod

[0040] 20 valve cone

[0041] 22 valve seat

[0042] 24 inlet area

[0043] 26 outlet area

[0044] 28 guide sleeve

[0045] 30, 32 half shells

[0046] 34-44 bolts

[0047] 46 drive-side connection device

[0048] 48 valve-side connection device

[0049] 50 coupling head

[0050] 52 bushing

[0051] 54 shoulder

[0052] 55 ball/ball holder device

[0053] 56 guidance device

[0054] 58 guide rail

[0055] 60 guide carriage

[0056] 62, 64 legs

[0057] 66, 68 sliding layers

[0058] 70 pointer

[0059] 72 marking