DE10235353A1 - Position regulator for drives of control valves has magnetic drive elements to transmit rotational position of feedback shaft to externally installed rotational position indicating element installed in Exd housing with window - Google Patents

Abstract

The position regulator for the positioning of actuating drives of control valves has a feedback shaft (1) guided on the inner wall of the regulator housing (10), and via magnetic drive elements (2,3) the rotational position of the feedback shaft is transmitted to an externally installed rotational position indicating element installed in a dust-protected housing constructed as a double-walled cap (12) provided with a window surface (13).

Description

The invention relates to a positioner for Positioning actuators for control valves, with between Actuator and controller coupling means in the form of a feedback shaft are provided, according to the preamble of claim 1.

Positioners are mostly used as valve actuators for Large process valves used. The valves of large nominal size are required for the regulated one Intervention in the process of a exact determination of the valve rod positions. The valve stem can either be lift operated or rotary operated be, after which the corresponding specific design of the Tap means designed. An example in the prior art are rotary-operation Valves. Here, a valve drive is provided, which on two diametrically opposite have output shafts lying on the sides of the drive. The lower one The output shaft acts on the mechanical through appropriate coupling Actuating means of the Valve. The upper output becomes the actual positioner fed. The positioner is in known designs, via a standardized mounting bracket attached to the valve actuator. Between the one facing the controller The output side of the drive and the controller itself find a mechanical one Coupling instead. For this purpose, the controller also has a shaft output on, which is coupled to the output shaft of the valve drive becomes.

To the regulated valve position at a greater distance to indicate, it is necessary to install an indicator. Such indicators that simply indicate the rotational movement of the return shaft of the controller for displaying are from the intrinsically safe devices known.

The interpretation becomes more problematic such a display device in controllers with Exd claim, because the necessary housing openings for optical detection only with disproportionately high costs are to be realized, e.g. B. Using tempered glass and complying with flame paths that fit perfectly.

The invention is therefore the object based on a positioner for positioning actuators for control valves to further develop the position of the return shaft also in fulfillment the Exd conditions can be read. and the design if possible is simply designed.

The object is achieved with respect to a device of the generic type according to the invention by the characterizing features of the claim 1 solved.

Further advantageous configurations of the pressure medium operated according to the invention Actuators are in the dependent claims specified.

The essence of the invention is that the return shaft is led to the inner wall of the controller, and via magnetic Driver elements the rotational position of the return shaft on an outside arranged rotational position indicator is transferable.

In an advantageous embodiment indicated that the Positioner housing is designed to be flameproof according to Exd (DIN 50018).

Furthermore, it is advantageously provided that the rotational position indicator dustproof in one with a window area provided protective housing is arranged, which is arranged at a corresponding point on the positioner housing is.

All in all, the invention for every possible Drive design suitable. The position or the rotational position of the Feedback shaft can be easily read, although the positioner housing is explosion-proof Executed according to DIN 50018 is.

The designs can be single-acting, double acting, linear or pivoting. In each of the above Cases are the advantages mentioned known designs can be achieved. The invention is in the drawing shown and below in more detail described.

It shows:

1 Lid arrangement of a positioner according to the invention.

2 Arrangement on rotary actuator.

1 shows a side sectional view of the lid assembly of a positioner according to the invention 10 , This is used to position the actuator for control valves. The valve as such is not shown further here. The return shaft 1 which leads to the actuator or to the valve drive is with a rotating magnet 2 connected. The return shaft 1 with the magnet 2 ends below the lid 11 this arrangement. In the case of known positioners, the return shaft would be guided outwards through a rotary leadthrough in order to be readable from the outside in its rotational position.

However, in order to meet the above-mentioned explosion protection and explosion protection requirements, the rotary movement below the cover is carried out according to the invention 11 ending return shaft 1 by means of a magnet 2 the one on the return shaft 1 is attached to a rotatable magnet 3 transferred to the top of the lid 11 is arranged. This is in a double-walled cap 12 rotatably, and is rotated by the magnet 2 the return shaft 1 taken. In this way, it serves as an implementation-free one Rotary coupling.

The rotational position of the feedback shaft 1 can through a window 13 can therefore be easily read from the outside without having to seal a shaft leading to the outside. In this way, all requirements for Ex and Exd protection are met.

2 shows a positioning with positioner 10 in its closed design. On the mounting flange 30 the drive shaft can be seen, which is led down to the valve, not shown here.

1

Feedback shaft

2

magnet

3

magnet

10

Positioner housing

11

cover

12

double Plastic cap

13

window

30

mounting flange

Claims (3)

Positioner for positioning actuators in control valves, coupling means in the form of a feedback shaft being provided between the actuator and the controller, characterized in that the feedback shaft ( 1 ) up to the inner wall of the positioner housing ( 10 ) is guided, and via magnetic driver elements ( 2 . 3 ) the rotational position of the feedback shaft ( 1 ) to an outside position indicator element ( 4 ) is transferable. Positioner according to claim 1, characterized in that the positioner housing ( 1 ) is designed to be flameproof according to Exd (DIN 50018). Positioner according to claim 1 or 2, characterized in that the rotary position indicator element ( 4 ) dust-protected in one with a window surface ( 13 ) provided as a double-walled cap ( 12 ) designed protective housing is arranged, which at a corresponding point on the positioner housing ( 10 ) is arranged.