Patent ID: 12247676

DETAILED DESCRIPTION

In the description hereunder of different embodiments of the invention, functionally equivalent elements have the same reference signs, even if said elements differ in design or shape.

The figures show at least parts of actuating drive assemblies which in their entirety are in each case identified by the reference sign1.

Each of the actuating drive assemblies1shown comprises an actuating drive2, a ball screw drive3driven by the actuating drive2, and a linearly activated fitting4.

The ball screw drive3comprises a nut5and a spindle6which is at least indirectly connected to the fitting4.

The fitting4is able to be opened by means of an opening movement of the spindle6which is driven by way of the actuating drive3and the nut5, said opening movement being directed in the opening direction of the fitting4. The fitting4can be closed again by means of a restoring movement caused by a restoring unit7and acting on the spindle6, said restoring movement acting in the closing direction of the fitting4. The restoring unit7comprises at least one restoring element8, for example a restoring spring. The restoring movement that acts on the spindle6when closing the fitting4here is a restoring movement and/or a relaxing movement of the restoring element8of the restoring unit7.

The ball screw drive3is able to be driven by a drive motor9of the actuating drive2. In the actuating drive assembly1shown inFIG.1, the restoring unit7and the actuating drive2are integrated in a fail-safe unit10. In the exemplary embodiment of an actuating drive assembly1shown inFIG.2, a separate restoring unit7is used.

The actuating drive assembly1, here the respective actuating drive2, comprises terminal switches for the fitting4. The terminal switches can define terminal positions of the fitting4.

The actuating drives2of the actuating drive assemblies1shown in the figures have in each case a rotary encoder11. The rotary encoders11are specified for detecting terminal positions of the respective fitting4. With the aid of the rotary encoders11it is possible for a rotating movement of the respective nut5to be ascertained in the process and to mathematically convert said rotating movement to a linear movement acting on terminal detents.

FIG.3highlights that the nut5of the ball screw drive3shown there is also mounted by means of an axial bearing12. The axial bearing12is disposed such that said axial bearing12is specified for absorbing axial forces that are transmitted to the spindle6by way of the restoring movement. In this way it is possible for comparatively high restoring forces to be transmitted from the spindle6to the nut5.

The spindles6illustrated inFIGS.3and4have a thread pitch of 16 mm.

According to the two block diagrams ofFIGS.1and2, each of the actuating drives2shown comprises a brake unit13. The brake units13comprise in each case an operating current brake14and a centrifugal brake15.

Two gearboxes, specifically a worm gear16and a planetary gear17, are provided between the drive motor9of the actuating drive2and the ball screw drive3. The worm gear16as well as the planetary gear17are in each case not configured so as to be self-locking. The rotation of a drive output shaft of the drive motor9of the actuating drive2can be deflected by 90° with the aid of the worm gear16. A reduction of the rotating speed introduced by way of the worm gear16into the planetary gear17is possible with the aid of the planetary gear17. The rotating speed which for driving the spindle6is transmitted from the planetary gear17to the nut5of the ball screw drive3is thus lower than the rotating speed by way of which the drive output shaft of the drive motor9of the actuating drive2rotates. However, by means of the reduction provided by the planetary gear17, in this instance a higher torque bears on the nut5such that not only can the fitting3be moved from the closed position thereof to the open position thereof but the restoring force of the restoring unit7can also be overcome by activating the spindle6.

FIGS.1and2highlight that a releasable interface18is configured between the ball screw drive3, specifically between the spindle6of the ball screw drive3, and the restoring unit7. The releasable interface18can be opened when closing the fitting. The is performed by tensile forces that act on the interface18, acting in each case in the closing direction and also in the opening direction. The releasable interface18between the spindle6and the restoring unit7can open in particular when the fitting4is closed and the spindle6, by virtue of the mass inertia thereof and/or of the mass inertia of the drive motor9, potentially overruns somewhat.

In order for the fitting4to be moved to the open position thereof with the aid of the spindle6, and for the spindle6with the aid of the restoring unit7to be impinged with the aid of the restoring unit7during the self-acting closing of the fitting4, and for the restoring movement of the restoring unit7to be transmitted to the spindle6, the interface18is specified for transmitting compressive forces in the closing direction and in the opening direction.

In order to prevent that the spindle6under axial loading rotates relative to the nut5driving the spindle, the interface18is moreover also specified for rotationally fixing the spindle6. For this purpose, the interface18has a guide element19which can be configured as a feather key, for example. The interface18, with the aid of the guide element19, is specified for coupling a drive output of the restoring unit7to the spindle6. The guide element19here permits axial play which is of such a dimension that the rotational fixing of the spindle6is maintained when opening and closing the fitting4. The rotational fixing of the spindle6is thus not canceled during the orderly operation of the fitting4.

FIG.4shows an exemplary embodiment of an actuating drive assembly1in which a bush22is provided for rotationally fixing the spindle6. The bush22is specified and provided for preventing relative rotation between the spindle6and the bush22and between the spindle6and the housing part26. The bush22here is mounted so as to be axially displaceable in the housing part26and is simultaneously axially fixed to the spindle6.

The bush22has an internal toothing23and an external toothing24. The internal toothing23of the bush22engages with a corresponding external toothing25of the spindle6. The corresponding toothings23and25reliably prevent the spindle6from rotating relative to the bush22. The bush22is axially established on the spindle6and moves conjointly with the spindle6when the spindle6moves in and out within the housing part26, the latter surrounding the spindle6and the bush22.

An internal toothing27which is configured so as to correspond to the external toothing24of the bush22and engages with the external toothing24is configured in the housing part26. The external toothing24of the bush22and the internal toothing27of the housing part26prevent the bush22from rotating within the housing part26but do permit an axial displacement of the bush22within the housing part26.

The corresponding toothings23and25as well as24and27can also withstand comparatively high forces and provide a high rotational resistance across the entire axial adjustment range of the spindle6.

According toFIGS.3and4, a receptacle space28into which the spindle6can overrun without colliding with components of the actuating drive assembly1is in each case provided in the housing29. Additionally or alternatively to the receptacle space28, a damping element could also be used for damping an axial overrunning movement of the spindle6and for avoiding a collision between the spindle6and components of the actuating drive assembly1.

An axial stroke of the fitting4between the open position thereof and the closed position thereof, and an axial stroke of the spindle6that is traveled by the spindle6in order to move the fitting4between the open position of the latter and the closing position of the latter, are of such a dimension that balls20of the ball screw drive3cannot perform a complete recirculation in the ball screw drive3.

In the actuating drive assemblies1which are at least partially shown inFIGS.1to3, the ball screw drives3are thus used for activating a self-closing, linearly activated fitting4. It is provided here that a nut5of the ball screw drive3for opening the fitting4is driven by an electric motor, as a result thereof a spindle6of the ball screw drive3is moved in a translatory manner in the opening direction of the fitting4, and the fitting4is opened as a result. For closing the fitting4, a linear restoring movement, here a relaxing movement, is transmitted to the spindle6. The restoring movement can be a relaxing movement which is imparted by a pressurized medium which is switched by the fitting4. The restoring movement can also be a relaxing movement of the restoring unit7, already mentioned above, of the previously described actuating drive assembly1. To this end, the restoring unit7has at least one restoring element8, as has likewise already been explained above.

A restoring force that has been introduced into the spindle6by the restoring movement can be at least partially dissipated behind the ball screw drive3and in part also by the ball screw drive3. In the actuating drive assemblies1illustrated inFIGS.1and2, the dissipation of the restoring force is performed by the brakes14and15of the brake units13of the actuating drive assemblies1illustrated.

At the end of the restoring movement the spindle6may overrun and be released from the fitting4. In the exemplary embodiments of the actuating drive assemblies1shown in the figures, the release of the spindle6is performed at the interface18, between the spindle6and the restoring unit7.

FIGS.1and2show that the fitting is connected to a line21, for example a pipeline. A medium, which is potentially pressurized and can be switched by the fitting4, flows through the line21. A flow through the line21is disabled in the closed position of the fitting4. The line21is passable when the fitting4is opened by way of the ball screw drive3.

According toFIG.4, a distal end of the spindle6is surrounded by a wiper ring25which prevents ingress of dirt as a result of the movement of the spindle6.

The invention is directed toward improvements in the technical field of actuating drives2. Proposed to this end is, inter alia, the use of a ball screw drive3for activating a self-closing, linearly activated fitting4. While the opening of the fitting4by means of an actuating drive2takes place by an electric motor by way of the ball screw drive3, a restoring movement is transmitted to the spindle6and from the latter to the nut5of the ball screw drive3when closing the automatically closing fitting4. The restoring movement, and thus also a closing movement of the fitting4, can be decelerated by way of the ball screw drive3, in particular by means of the centrifugal brake15, this being able to protect the fitting4and ultimately also the ball screw drive3and moreover optionally further components of an actuating drive assembly1from damage, and moreover also being able to facilitate a fail-safe function.

LIST OF REFERENCE SIGNS

1Actuating drive assembly2Actuating drive3Ball screw drive4Fitting5Nut6Spindle7Restoring unit8Restoring element9Drive motor10Fail-safe unit11Rotary encoder12Axial bearing13Brake unit14Operating current brake15Centrifugal brake16Worm gear17Planetary gear18Interface between6and719Guide element20Ball21Line22Bush23Internal toothing of2224External toothing of2225External toothing of626Housing part27Internal toothing in628Receptacle space29Housing