FI116311B - Device that adjusts activator - Google Patents

Description

116311

THE INSTITUTION'S MOTION CONTROL DEVICE

The invention relates to a device for controlling and maintaining the movement of an actuator, such as a valve stem, comprising a rotary motor, a gearbox, a shaft actuated by a gear, a bearing on said shaft, by means of which the position of the actuator or its attachment means is recognized.

10

An application for detecting a position of a spindle in connection with a valve spindle is previously known from application FI-980180, wherein a deflection portion on the spindle is led out of the spindle movement arm and the movement of the spindle is further directed to a position sensor.

15

In the solution described above, the position sensor is not able to accurately control the movement of the spindle, but the movement is sensed from the clearance section, whereby some accuracy is already lost. The movement is transmitted outside the shaft system, whereby the shaft is exposed to a different temperature as compared to the body parts of the device and the accuracy may be impaired, e.g. 20 due to its thermal extension properties. Outside drive shaft: ··; * easily damaged and dirty in use. The lateral leakage of the movement arm out of or in the vicinity of the spindle is also difficult to accomplish because the spindle or the like is at the point in question; The j! Usually slides and moves inside the tube or cylinder.

I I t • · I '· * f! 1. ΐ; ; The actuator movement control device according to the invention solves the above problems, * and avoids the disadvantages of existing devices. The device according to the invention is characterized in that a rod for transmitting linear motion from an actuator or a fastening member guiding it is disposed within the axis of motion, the other end of which is guided out of the shaft and cooperates with the position sensing sensor.

F ': The device of the invention has the advantage of providing a backlash free movement from the mandrel to the sensor. · · The transmission rod is protected inside the shaft. The bar temperature can hardly differ from that of the device **! · * '*. ·, The current body temperature, so there is no loss of motion.

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It is also relatively easy to make a shaft hollow or make a tube.

2 116311

In the following, the invention will be explained in more detail with reference to the accompanying drawing, in which Figure 1 shows a sectional view of a valve actuator.

Figure 2 is a schematic view of the device of Figure 1 in some respects.

5

Figure 1 shows an actuator for adjusting linear motion of the valve stem. If necessary, the control circuit rotates the motor 14 according to how the spindle motion detector 11 detects signals to correct the position. After the motor 14 there are reduction gears 9 and 10 through which the shaft 15 is rotated. The upper end of the shaft 15 has a bearing 10 8. The lower end of the shaft 15 has a gear, by means of a screw / nut principle, by which the rotation of the shaft 15 is converted into a linear movement of the spindle or its fastening part 1. The gear unit has two nuts 3 and 4 which can be tightened against one another by means of the third nut 5, thereby eliminating the play clearance from this gear unit.

15 Conducting motion as described above for spindle or the like is known in the art. According to the invention, the shaft 15 is inside a hollow shaft and a rod 2 is disposed which is guided by the movement of the spindle or the like portion 1 to the position sensor sensor 11 without a clearance and protected as a position sensor sensor 11.

20; ί The electrical sensor 11 is placed close to the electronic unit and avoids the wiring that would occur if the sensor 11 were located outside the housing 13. The device body outside the housing 13 becomes simple because the output of the actuator is not directed to the sensor; for the pole now needed.

'25 »

It is also possible that immediately after the gearbox 10, 9 a linear movement of the rotational movement is effected, e.g. by a screw / nut arrangement, whereby the hollow shaft corresponding to the axis 15: makes the linear movement and the spindle part 1 either linear or rotational. , *,: The rod 2 leading to the sensor is within said hollow shaft according to the invention.

V: 30 1 * * '

Claims (2)

A device which adjusts and maintains movement of an activator, as well as a locking member in a valve, comprising a rotary motor (14), a gear (9,10), a shaft (15) as the gear rotates, stores (8) for said shaft, furthermore, a gear is most preferably a screw arrangement (3, 4) which converts rotational movement to linear movement, movement connection from the screw arrangement (3,4) to the movable actuator or to the conductive fastener (1) and a transducer device (11, 12), by which there is linear movement of the activator 10 or of a fastener (1) leading to the activator, characterized in that rod (2) which transmits linear movement of the activator or of the fastener leading to it is positioned to move into the movement shaft (15), one end (12) of which the rod is led out of the shaft (15) and is in cooperation with position known sensor (11). Device claim 1, characterized in that the one end of the closure (2) is fixed in the movable part of the actuator, as well as in the locking member of the valve, or in a fixed part (1) which transmits movement to said part and the other end is movably positioned in position. sensing sensors (11). 20 • t t f f f 25 t I * i t 1> »i 30 ί ('I * * I ·' Mi» »» »