JPS6252285A - Actuator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an actuator for a valve having a disengagement device, and in particular to an actuator for a valve, the actuator having a motor and a gearing, the gearing being Mounted with provision for limited longitudinal movement (having a force transmitting element pulled and supported between springs, the overload release device having a member for sensing the restricted movement of the force transmitting element) However, such a member is operatively associated with a start and shut-off switch for the motor.

Prior Art This type of actuator is known as Cl-1-PS57667.
2, in which the disengagement device includes a two-armed lever extending through a hole in a casing extending around the gearing. The hole also accommodates a bushing to which the fulcrum of the lever is attached. One arm of this lever has two arms that are actuated individually according to the direction in which the lever rotates.
The end of the lever extends out of the casing between the two switches. The other arm of the lever carries a ball bearing supported on one side of an annular disc attached to a force transmitting element at its end. The spring between the bushing and the first mentioned lever arm ensures that the lever arm carrying the ball bearing is always pressed into engagement with the ring disc, so that the lever senses all movements of the force transmitting element. I'm making sure that there are. It has been found that the use of a spring between the bushing and the lever arm does not provide sufficient reliable operation, for example in the event of spring weakening or breaking. In such cases, the disengagement action in response to an overload position of the device connected to the force transmitting element is delayed or does not occur at all;
Equipment and/or actuator performance is damaged. Too much difficulty exists in the placement of the spring between the bushing and the lever, as both switches get in the way when the spring is returned to its original position - ie, the mounting of the switch has to be removed.

SUMMARY OF THE INVENTION The object of the invention is to provide an actuator of the kind described so far, in which the reliability of operation of the release device is improved.

Therefore, according to the invention, the sensing member comprises a toothed rack connected to two force transmitting elements; and a pinion meshing with the rack. This feature is that there is no need to provide special springs for the connection between the sensing member and the force transmitting element, providing a permanent non-secure and positive connection as this connection. The reliability of operation is therefore improved since the sensing member is reliably involved in every movement of the force transmitting element. Delayed operations are therefore avoided. If, in the case of an actuator, the switch is arranged outside the housing for the gearing, it is structurally simple to seal off the parts that need to extend outward through the housing wall.

Other advantageous features of the invention are set out in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS 51 Embodiments of the invention are described in more detail hereinafter with reference to the drawings.

Embodiment Referring to FIG. 1, the actuator is a gear device 19
．． 19a and two coaxial holes 2.3
It has a casing 1 formed by comprising. The gearbox cover 4 is attached to the casing 1 by a number of screws 6 located in the top holes 2 in FIG. 1 and extending through the flange 5 of the cover 4. A bottom bearing cover 7 is attached to the bore 3 in a manner not shown in great detail. A bronze spindle nut 15, extended by a hollow cylinder, is housed in a central hole 11.12 in each of the covers 4.7 and
each has a seal 8°9 around it. A key 16 secures the steel ring 17 to the spindle nut 15 with which the ring 17 rotates. However, the nut 15 has provision for limited axial movement relative to the ring 17, with the key 16 sliding in the keyway 16a of the ring 17 in this case. The key 18 thus connects the ring 17 to the bronze worm wheel 19, so that the worm wheel 19 and the ring 17 rotate together: the worm wheel 17
9a to form a gearing, which is driven by an electric motor (not shown). ring 1
The worm wheel 19 is mounted between two axial ball bearings 20 and 21. The ball bearing 20 is located on the end face 22' of a sleeve-like part 22 of the casing 1, and the part 22 is connected to the nut 1.
The bearing 21 extends around the bottom part of the bearing cover 5 and projects radially inwardly, while the bearing 21 is supported on the inner end face of the bearing cover 4. Ring 17 is ring 2
6 is supported on one side by a set of disc springs 25 at the top, and in the ring 26 a resilient locking washer 27 is attached to the nut 1.
5 and a ring 17 on the other side of the bottom set of disk springs 30. Threaded sleeve 31 and oak 1
It is supported by a circular toothed rack 32 on a second resilient stop washer 33 held at -15. A threaded spindle 55 is disposed therein, and at its top, unthreaded end two gears 58 are inserted into each of the two axial grooves 60, 61 in the dome 62 by means of a key 56. , 59 is fixed. The dome 62 is closed at its top end (not shown) and secured to the top bearing cover 4.

The actuator has a cercin transmitter that indicates the instantaneous position of the spindle 55 and therefore the position of the device, such as the valve, actuated by the actuator. All of the Sercin transmitters shown here have threaded sleeves 31, the same carrying two starting threads 31, the pitch of which is the same as that of the spindle nut 15.
The threads 11115b mesh with a helical gear (not shown) in a plane equal to the pitch of b and perpendicular to the plane of the drawing.

The actuator also has an overload relief device, which operates in response to an overload, for example by a forcefully pushed outer body, or in both of the two end positions of the spindle 55, to stop the drive motor. This allows the drive motor to move away from the overload position corresponding to the drive motor. The overload release device is devised as follows: Nara+-151: The rack 32 with circular teeth is
The shaft 36 meshes with the pinion 35 on the instep.

The shaft 36 has a sleeve-like casing part 2
2 to the outside of the casing 1 (FIG. 2). A number of countersunk screws 38, which are internally hexagonal and extend through the flange 37' on the bushing 37, secure the flange 37' to the casing 1 from the outside. Pinion 35 and shaft A7 shaft 36
An abutment surface 35' at the transition between C and an elastic stop washer 39 meshing on the shaft 36 on the outside of the casing positions the pinion 35 and therefore the axial shaft 36 on the bush 37. A two-armed lever 4o is arranged on that end portion of the shaft 36 projecting from the bushing 37, and the lever 4o
o is held in the axial direction at the end portion between the elastic locking washer 39 and the hexagonal nut 41. Pin 42 secures lever 40 against rotation. At each of its two ends, the lever 40 has a threaded finger 43°4.
3', the fingers projecting upwardly in FIG.
' When activated, operate. Switch 44.44'
is thus connected to the drive motor, and the pushbutton 45
．． While 45' is in the pressed state, the corresponding direction of rotation of the motor is blocked.

The motor operates as follows: In response to an actuation signal applied to a drive motor (not shown), the drive motor is actuated by gearing 19.19 to move nut 15 in one direction or the other. It rotates and the spindle 55 moves up or processes. If spindle 55 is connected to the valve lid, movement of spindle 55 opens or closes the valve, and cooperating synchro oscillators such as sleeve 31 adjust the position of spindle 55 and
Therefore, it indicates the operating position of the valve lid.

Depending on the direction of movement of the spindle 55, the nut 15
As it rotates either against the return saw of disk spring 25 or against the return force of disk spring 30,
Move, Natsu 1-15 to ring 17 (pull key @1
It is slid by the key 16 of 6a. The momentum of the nuts 1 to 15 depends on the load on the spindle 55. Once such a movement exceeds a predetermined value, as occurs, for example, when the valve lid reaches its closed position, the internal toothed rack 32 will displace the shaft 36 and therefore the , for example, the pinion 3 with the lever 4° until the finger 43 actuates the associated pushbutton 45 of the switch 44.
5 and prevents further rotation of the drive motor in its previous direction. Since the pushbutton 45' of the other switch 44' is not actuated, the drive motor can be started immediately and moved in the opposite direction of rotation, if necessary, in the direction of rotation of the nut 15 and the movement of the spindle 55. The direction is also reversed, while the disc spring 25 or 30 initially pushes the nut 15 back into its neutral initial position.

The pinion 35, shaft 36 and lever 40, even though they experience little return stress and are of relatively elongated construction and are manufactured without particularly stringent requirements, are suitable for the described use. forming a generally single component with high dimensional stability. pinion 3
5 and the rack 32 can be manufactured with great precision with reduced manufacturing costs, and the mounted state of the nut 15 and shaft 36 has a greatly reduced backing. It ensures a rush.

Other factors that assist here are switches 44, 44'
and the respective pushbuttons 45, 45' are arranged on the same side of the two lever arms and react generally identically in the overload release device, so that any backlash is generally in the same groove and in the same direction in both directions of rotation. has been reduced. The course of the tests was such that, as previously mentioned, the forces acting on the nut 15 in one direction of movement differed by less than 2% from the corresponding forces operating for movement in the other direction.

If necessary, a ring seal can be arranged between the shaft 36 and the bushing 37 and between the latter and the part 22.

Instead of the lever 4o, a cam or similar 4 is used and a number of consecutively connected switches 44.4
4' can be operated in redundant states at the same time, thus increasing operational reliability.

The gearing may be other than a worm gearing and the spring may be implemented by other than a disc spring. The switching device may be electrical or mechanical or hydraulic or pneumatic, for example. The toothed rack 32 is nut 1
5, the toothed rack 15 may be connected to the nut 15 by a bearing, for example a rolling bearing, in which case the nut can rotate without the rack 32.

The pinion 35 may also have a shaft corresponding to the shaft 16 at its bottom end, as shown in FIG. It is attached by.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the actuator according to the invention near the force transmitting element; FIG. 2 is a line I[ of FIG.
-I; and FIG. 3 is a partial view taken in the direction of arrow A in FIG. DESCRIPTION OF SYMBOLS 1... Casing, 15... Spindle nut, 19... Worm wheel, 19a... Worm, 25.30... Belleville spring, 32.33... Toothed rack, 35. 35'...Pinion, 4o...Lever, 44.44'...Switch, 55...Threaded spindle.

Claims (4)

[Claims] (1) An actuator for a valve having a release device, more particularly an actuator for a valve, having a motor and a gearing device, the gearing device being mounted with facilities for limited longitudinal movement and between springs. an actuator having a supported force transmitting element, the disconnection device having a member for sensing limited movement of the force transmitting element, and such member being operatively associated with a start and shut off switch for the motor; ,
The sensing member has a disengagement device characterized in that it includes: a toothed rack connected to a force transmitting element; and a pinion meshing with said rack, more particularly an actuator for a valve. (2) An actuator according to claim 1, having a release device characterized in that the rack has circular meshing teeth and extends around the force transmission element, more particularly the valve Actuator for. (3) An actuator according to any one of claims 1 or 2, wherein the pinion has a shaft extending through the casing around the gearing, and an end thereof extending outside the casing. A release device characterized in that it has a lever actuated on a switch, more particularly an actuator for a valve. (4) An actuator according to claim 3, in which the force transmitting element is a spindle nut cooperating both with a rotationally mounted spindle and also with a gearing, and the lever is a two-armed lever. and the switch is configured such that one switch is actuated by one lever in response to pinion rotation in one direction and the other lever is actuated by another lever in response to pinion rotation in the other direction. and more particularly for a valve, the disconnection device being arranged in actuator.