Valve actuator for adjusting a valve piston of a valve

Abstract

Valve actuator (1) for adjusting a valve piston (25) of a valve (24), wherein at least one drive motor (5) having a drive shaft rotatable about a rotation axis (6) is arranged, wherein at least one spindle drive unit (4) is arranged for converting the rotation of the drive shaft into a linear adjustment (P) of the valve piston (25), wherein the spindle drive unit (4) comprises at least one spindle shaft (3) and at least one spindle nut (2) operatively connected to the spindle shaft (3) in a drive phase of the drive motor (5), wherein at least one nut-coupling unit (18, 19) is arranged for engaging and disengaging the spindle nut (2), wherein the spindle nut (2) has at least two operating positions corresponding to an engaged, first coupling state and a disengaged, second coupling state, wherein the nut-coupling unit (18, 19) is designed such thatto move the spindle nut (2) from one of the operating positions to the other operating position, characterized in that the nut-coupling unit (18, 19) is designed as an adjusting device (18, 19) for adjusting or at least partially spacing the spindle nut (2) at least partially transversely to the axis of rotation (11) of the spindle shaft (3), that the adjusting device (18, 19) comprises at least one pivot axis (16) for pivoting the spindle nut (2) and that the pivot axis (16) is aligned transversely or perpendicularly to the axis of rotation (11) of the spindle shaft (3).

Description

[0001] The invention relates to a valve drive for adjusting a valve piston of a valve, wherein at least one drive motor having a drive shaft rotatable about a rotation axis is arranged, according to the preamble of claim 1. State of the art

[0002] Valve actuators for adjusting a valve or valve piston have long been in use. Linear motors, electromagnets, electric coils, or actuators with spindle drives are among the devices used. While linear motors or electromagnets can be adjusted relatively quickly, they have only two or a few switching positions and relatively small actuating forces. Larger actuating forces require a large installation space and high unit costs, which are intolerable in many applications, such as hydraulic systems / controls with relatively high pressure.

[0003] Actuators with spindle drives, on the other hand, have the great advantage of being able to achieve very high actuating forces without requiring much space / installation space, and some are very cost-effective. Spindle drives can be implemented with a wide variety of pitches and adapted to the application. However, particularly high actuating forces can only be achieved with comparatively small pitches. In the event of a power failure, emergency, or similar, spindle drives with small pitches remain in the corresponding position due to their self-locking feature. This is not permitted in some applications, such as hydraulic valves in hydraulic systems, so this drive system cannot currently be used in these applications.

[0004] In addition, special valve actuators with a spindle and nut are already known, e.g., from EP 2 228 573 B1. This allows for a quick-action closure during the closing process, which, among other things, enables emergency shutdown. However, this is only possible with a threaded spindle without self-locking, i.e., with a comparatively large thread pitch. The actuating forces for small electric motors are correspondingly small. Large actuating forces, in turn, require large electric motors, which are both expensive and require a lot of installation space.

[0005] Furthermore, DE 10 2011 103 135 A1 discloses a valve actuator with an electric motor-driven spindle and nut, as well as a freewheel or quick-adjustment system. This valve actuator is designed to open with virtually no delay to prevent faulty ignition attempts in a burner's combustion chamber. Object and advantages of the invention

[0006] The object of the invention is to propose a valve drive for adjusting a valve and / or valve piston, which improves the state of the art, in particular in an emergency and / or in the event of a power failure, can assume a predetermined position or safe rest position.

[0007] This object is achieved by the features of claim 1, starting from a valve drive of the type mentioned in the introduction. Advantageous embodiments and further developments of the invention are possible by the measures mentioned in the subclaims.

[0008] Accordingly, a valve drive according to the invention for adjusting a valve piston is characterized in that the nut-coupling unit is designed as an adjusting device for adjusting or at least partially spacing the spindle nut at least partially transversely to the axis of rotation of the spindle shaft, that the adjusting device comprises at least one pivot axis for pivoting the spindle nut and that the pivot axis is aligned transversely or perpendicularly to the axis of rotation of the spindle shaft.

[0009] With the help of this type of nut-coupling unit, the spindle nut can be uncoupled from the shaft or spindle shaft, so that the valve or valve piston can assume a defined position or predetermined, safe rest position in the event of an emergency or power failure, among other things. The spindle nut, which is advantageously not in active connection with the shaft / spindle shaft in the second, uncoupled coupling state, enables the valve drive to be adjusted particularly quickly and / or easily in terms of the actuating force. This is a huge advantage for spindles with a flat or small pitch as well as for spindles with a steep or large pitch, i.e. also for spindles or shafts and spindle nuts with or without self-locking. Accordingly, actuators orValve drives according to the invention can be realized with small or even with particularly large actuating forces without requiring comparatively large and / or expensive drive motors.

[0010] In principle, various drive principles and systems are conceivable according to the invention. For example, on the one hand, a rotating shaft or spindle shaft and a "wandering" spindle nut or one that adjusts in the direction of the adjustment path can be provided. On the other hand, a rotating and "wandering" shaft or spindle shaft that adjusts in the direction of the adjustment path and a fixed spindle nut can be provided. In addition, a rotating spindle nut and a "wandering" shaft or spindle shaft that adjusts in the direction of the adjustment path can be provided. Also conceivable is a rotating and "wandering" spindle nut or one that adjusts in the direction of the adjustment path, with the shaft or spindle shaft being fixed.

[0011] Preferably, a shaft or spindle shaft that adjusts along the adjustment path and / or a spindle nut that is fixed or non-adjustable, i.e., does not "wander," is provided. This allows advantageous coupling and decoupling according to the invention to be realized using the nut-coupling unit. The design and cost-effectiveness are reduced or optimized compared to the other aforementioned principles.

[0012] Preferably, a shaft or spindle shaft that can rotate or rotate about a rotational axis and / or a stationary or non-rotatable or non-rotating spindle nut is provided. This also allows advantageous coupling or decoupling according to the invention to be realized by means of the nut-coupling unit. Alternatively or in combination with the aforementioned variant according to the invention, the design and economic effort can also be (additionally) reduced or optimized compared to the other aforementioned principles.

[0013] In general, it is advantageous to provide a torque support or torque support, whereby the torque of the drive motor or rotating spindle element (shaft or nut) can be absorbed or supported / dissipated on an armature element or housing or the like.

[0014] Advantageously, at least one holding device is provided for holding and / or arranging the spindle nut on a housing element. This advantageously allows the torque of the drive motor or the rotating shaft to be absorbed or supported / dissipated on a housing element or the housing or the like.

[0015] A particularly preferred variant of the invention comprises a spindle drive unit with a shaft or spindle shaft and a spindle nut, wherein the shaft has at least one thread and the spindle nut has at least one threaded portion for the thread. Advantageously, the threaded portion is engaged with the thread in the first coupling state, and the threaded portion is disengaged from the thread in the second coupling state.

[0016] Within the meaning of the invention, however, a spindle drive unit can also be provided with a shaft or spindle shaft and a spindle nut that does not have a thread. For example, such a drive system has become known as a frictional transmission, whereby a smooth shaft and a so-called "rolling nut" are used to convert rotation into linear movement / adjustment. These rolling nuts from Uhing have roller bearings or rolling rings that are arranged at an acute angle to one another and press against the shaft, so that during a rotational movement between the shaft and rolling nut, the rings roll on the shaft surface at their position angle. Accordingly, a linear adjustment within the meaning of the invention is possible.

[0017] Such drive nuts advantageously have a locking device, which allows engagement and disengagement, or a nut coupling unit, within the meaning of the invention. The compact design and the overload protection provided here are advantageous here. However, comparatively large coupling forces are required to engage / disengage the locking device in order to generate the frictional connection between the shaft and drive nut. Thus, spindle drive units according to the invention with a thread or thread pitch and / or threaded sections are preferable, i.e., with a threaded spindle and threaded nut.

[0018] For example, a spindle nut or threaded nut is provided that comprises at least two separate and / or spaced-apart threaded parts or threaded shells / half-shells. Thus, the nut-coupling unit or the adjusting device can advantageously be designed to space the at least two or possibly even three threaded parts or threaded shells apart from one another for decoupling or for the second coupling state and / or to adjust them transversely, in particular almost perpendicularly, to the linear adjustment / rotational axis of the spindle shaft. Thus, the spindle nut or the threaded parts can advantageously be disengaged from the shaft and reengaged as needed.

[0019] Preferably, the nut-coupling unit is designed to tilt the spindle nut and thereby transfer the spindle nut from one of the operating positions to the other. This allows for the advantageous use of a one-piece spindle nut, meaning that splitting or multiple separate threaded nut parts is not absolutely necessary, thus optimizing the design and cost-effectiveness.

[0020] In an advantageous variant of the invention, an extension of the pivot axis intersects the shaft's rotational axis. This allows for particularly low design and cost-effectiveness, while also being particularly compact and requiring little installation space.

[0021] To advantageously implement the first and second coupling states according to the invention, the spindle nut advantageously has at least a first threaded portion at a first end region viewed in the direction of the rotation axis, and a second threaded portion spaced apart from the first threaded portion in the direction of the rotation axis at a second end region arranged opposite the first end region when viewed in the direction of the rotation axis. Furthermore, the first threaded portion is advantageously arranged on a first side of the spindle nut viewed transversely to the rotation axis, and the second threaded portion is advantageously arranged on a second side of the spindle nut viewed transversely to the rotation axis.

[0022] This measure or measures advantageously enable the spindle nut to be pivoted about a pivot axis oriented transversely / perpendicularly to the rotational axis of the shaft, so that the nut is / remains arranged around the shaft in both the first and second coupling states. At least one smooth or threadless section of the spindle nut can approach the shaft during pivoting for the second, uncoupled coupling state, without the spindle nut engaging or coming into operative connection with the shaft. Accordingly, especially in the aforementioned variants of the invention, the coupling states are superimposed and arranged at an angle to one another.

[0023] In general, according to the invention, in the uncoupled or second, uncoupled coupling state, the spindle drive unit and / or the valve or the valve piston can be adjusted to a desired or arbitrary position or safe rest position without great (force) expenditure and comparatively quickly, particularly in an emergency and / or in the event of a power failure. For this purpose, at least one reset unit and / or return spring is advantageously provided for resetting the valve and / or valve piston and / or the shaft and / or the spindle nut. This advantageously eliminates the need for manual adjustment, and adjustment in the uncoupled or second, uncoupled coupling state can be automated or advantageously controlled.

[0024] Preferably, the reset unit is designed as an emergency unit for positioning and / or setting the valve and / or valve piston and / or the shaft and / or the spindle nut in an emergency position and / or the center of the adjustment travel. This is of great advantage for special and / or safety-relevant applications / areas of use and is legally required. Accordingly, a wide range of applications and numerous, particularly safety-relevant, areas of use open up for valve actuators according to the invention.

[0025] Advantageously, the reset unit comprises at least one electromagnet. This allows, for example, the electromagnet or electromagnetic coil or the like to be automatically or forcibly deactivated in the event of a power failure, allowing automatic reset to the desired position or the emergency position and / or the center of the adjustment range. Consequently, this advantageously enables absolutely safe operation even in the event of a power failure or similar event.

[0026] A wide variety of materials can be used for the spindle drive unit, e.g., plastic and / or metal elements. A combination of a brass nut and a steel spindle shaft is preferred, so that lubrication can be omitted if necessary. Example

[0027] An embodiment of the invention is shown in the drawing and is explained in more detail below with reference to the figures.

[0028] In detail: Fig. 1 a schematic side view of a valve drive according to the invention in the engaged state of a spindle nut, Fig. 2 a schematic, enlarged detailed view of Fig. 1, Fig. 3 a schematic, enlarged detailed view of the valve drive according to Fig. 1 in the disengaged state of the spindle nut and Fig. 4 a schematic, enlarged plan view of the valve drive according to the invention with a pivot axis of the spindle nut.

[0029] The figures show a preferred valve drive 1 according to the invention with a spindle drive unit 4 or a gear 4 with a spindle nut 2 and a spindle shaft 3. The valve drive 1 advantageously also comprises an electric or drive motor 5, in particular a DC motor, which has a motor / rotor shaft (not shown in detail) rotatable about a rotational axis 6 and drives an optionally provided reduction / transmission gear 7.

[0030] In the illustrated embodiment, a rotatable spindle shaft 3 is provided, which is connected to the gear 7 via an advantageous first clutch 8 and receives the drive torque of the drive motor 5. This first clutch 8 has a sleeve 8 or a hollow cylindrical element 8, on which, for example, a pin 10 or cross element 10 is arranged or fixed at one end, so that the pin 10 or the cross element passes through the sleeve 8. The spindle shaft 3 comprises an elongated recess or an elongated hole 9, in which the pin 10 or the cross element is arranged or guided, so that it can be adjusted in the longitudinal direction of the elongated hole 9.

[0031] This advantageously allows the drive torque of the drive motor 5 to be transmitted to the spindle shaft 3, wherein the spindle shaft 3 is adjustable or movable in the longitudinal direction or along the axis of rotation 11 (cf. directions of rotation D). This means that the spindle shaft 3 can "wander" along its axis of rotation 11. This linear adjustment or movement of the spindle shaft 3 (cf. directions of arrows P) is generated by means of the spindle nut 2 and the direction of rotation D of the spindle shaft 3 or by means of a thread 13 or threaded section 12 of each of the two components, i.e. the spindle nut 2 and the spindle shaft 3.

[0032] When the spindle nut 2 is engaged according to the Fig. 1 and Fig. 2, the two threads 13 or thread pitches engage with each other, so that from / with the direction of rotation D of the spindle shaft 3, a longitudinal adjustment or linear movement of the spindle shaft 3 is simultaneously generated. The spindle nut 2 remains firmly positioned or is held (stationarily) by means of torque supports or holder devices 14 arranged on both sides. The torque supports or holder devices 14 are fixed to a housing 15 and have an advantageous pivot axis 16 (cf. Fig. 4). Here, the spindle nut 2 comprises a shaft section 17 or shaft stub on each side.

[0033] The valve drive 1 according to the figures also comprises a (hydraulic) valve 24 or a valve piston 25, which is adjusted or controlled in the longitudinal direction P by means of the linear adjustment of the spindle shaft 3. Corresponding control / directional valves or the like are widely known, so that their operation and their structure, etc., need not be explained in detail here.

[0034] By pivoting the spindle nut 2 about the pivot axis 16 or about the shaft sections 17, the threaded section 12 of the spindle nut 2 is disengaged from the spindle shaft 3 or its thread 13. This is especially important in Fig. 3. Here it is also clear that the spindle nut 2 does not have a full or "complete" thread on the inside, as is the case with "normal" nuts. Rather, there are two separate threaded sections 12 at both ends arranged opposite each other in the longitudinal direction of the rotation axis 11. In addition, these threaded sections 12 each extend only over a comparatively small arc section of the spindle nut 2 or over its inner circumference, so that in the tilted, uncoupled state according to Fig. 3 the spindle nut 2 also has no threaded sections laterally, ie along the pivot axis 16, which engage with the thread 13 of the spindle shaft 3. Preferably, the two axes 11 and 16 cross / intersect (cf. Fig. 2 and Fig. 3).

[0035] This advantageous spindle nut 2 according to the invention can be produced, for example, by forming an advantageous oblique bore or cylindrical recess, ie at an acute angle W, in relation to the internal thread of the spindle nut 2, according to Fig. 3, is generated or introduced. The diameter of the bore / recess is advantageously almost the same as or slightly larger than the outer diameter of the spindle shaft 3.

[0036] In addition, two stops 21 are advantageously provided, which limit the adjustment or tilting of the spindle nut 2 or advantageously position the spindle nut 2 exactly in every position or every coupling state / positioning (cf. Fig. 2 and Fig. 3).

[0037] As in Fig. 3, the spindle nut 2 can be tilted at an acute angle W in order to disengage from the spindle shaft 3. For this purpose, an electromagnet 18 or a coil 18 with a return device or spring (not shown in detail) is advantageously provided, which generates the coupling of the spindle nut 2 according to the invention via a lever 19. The lever 10 or the actuator element 19 is in turn rotatably mounted, with an axis 20 and preferably also the lever 19 each advantageously arranged at a distance from the spindle nut 2.

[0038] Thus, in a special operating case, such as an emergency or a power failure, by switching off or checking and / or by a power failure, it can be achieved that the spindle nut 2 is switched off from the engaged state according to Fig. 2 in the uncoupled / disengaged state according to Fig. 3 is changed or changes / switches. The spindle shaft 3 is thus "exposed" or unlocked and freely adjustable or freely movable in the longitudinal direction of the rotational axis 11, i.e., freely adjustable in both directions and with particularly low force or quickly. Accordingly, in this uncoupled state, the spindle shaft 3 can "slip through" the spindle nut 2, and the electromagnet 18 acts or implements a type of "first reset device" according to the invention.

[0039] As in Fig. 1, an advantageous further or “second” return unit 22 with a return spring 23 is provided at an end of the valve drive 1 opposite the drive motor 5. This causes the spindle nut 2 or spindle shaft 3 to be disengaged according to Fig.3 that the spindle shaft 3 (automatically) adjusts or moves very quickly along the rotational axis 11 in the direction of the drive motor 5. The achievable return path of the spindle shaft 3 depends on a favorable stop or a distance A of the return unit 22. This is preferably selected / adjusted such that the spindle shaft 3 is positioned in a middle position or the center position. This makes it possible, for example, to meet corresponding specifications or regulations in certain areas of application, which expands the use or application area of ​​the valve drive 1 according to the invention, e.g., for certain hydraulic applications, safety applications, or the like.

[0040] Alternatively, manual positioning in the uncoupled state can also be carried out or realized, e.g. in a special application, the spindle shaft 3 is only uncoupled or "released" according to the invention or by means of the spindle nut 2 and can then be adjusted manually (as desired).

[0041] In general, by means of the valve drive 1 shown, on the one hand, an adjustment of the valve 24 or valve piston 25 can be achieved with very large actuating forces during normal operation, in particular by means of the step-up / reduction gear 7 and comparatively "flat" thread pitches / threads of the threads 13. On the other hand, a secure positioning or control of the valve 24 or valve piston 25 can be achieved even / especially in the event of a power failure, in particular by means of the advantageous spindle nut 2 or the electromagnet 18 or lever 19. In addition, this positioning or resetting can be carried out particularly quickly by means of the advantageous resetting unit 22, which further increases safety. Alternatively, any other rest positions of the valve 24 or valve piston 25 can also be realized, e.g. in the end position or any intermediate positions that can be set using the distance A.

[0042] The components used are also comparatively inexpensive and require relatively little installation space, which has a particularly positive effect on cost-effectiveness and space requirements. List of reference symbols 1 valve actuator 2 spindle nuts 3 spindle shaft 4 gearboxes 5 Drive motor 6 Rotation axis 7 gearboxes 8 Coupling / Sleeve / Hollow Cylinder Element 9 slotted hole 10 pens 11 Axis 12 threaded section 13 threads 14 Holding device 15 housings 16 Axis 17 Wave 18 Electromagnet / Coil 19 Lever / actuator element 20 axis 21 stop 22 Reset unit 23 spring 24 valve 25 valve pistons 26 stop A distance D Direction of rotation P Longitudinal direction W angle

Claims

[1] Valve drive (1) for adjusting a valve piston (25) of a valve (24), wherein at least one drive motor (5) having a drive shaft rotatable about a rotational axis (6) is arranged, wherein at least one spindle drive unit (4) is arranged for converting the rotation of the drive shaft into a linear adjustment (P) of the valve piston (25), wherein the spindle drive unit (4) comprises at least one spindle shaft (3) and at least one spindle nut (2) operatively connected to the spindle shaft (3) in a drive phase of the drive motor (5), wherein at least one nut-coupling unit (18, 19) is arranged for coupling and uncoupling the spindle nut (2), wherein the spindle nut (2) has at least two operating positions corresponding to an engaged, first coupling state and an uncoupled, second coupling state, wherein the nut-coupling unit (18, 19) is designed such thatto move the spindle nut (2) from one of the operating positions to the other operating position, , characterized by that the nut coupling unit (18, 19) is designed as an adjusting device (18, 19) for adjusting or at least partially spacing the spindle nut (2) at least partially transversely to the axis of rotation (11) of the spindle shaft (3), that the adjusting device (18, 19) comprises at least one pivot axis (16) for pivoting the spindle nut (2), and that the pivot axis (16) is aligned transversely or perpendicularly to the axis of rotation (11) of the spindle shaft (3). [2] Valve drive according to claim 1, characterized by that the spindle shaft (3) is rotatable about a rotation axis (11) and that at least one holding device (14) is provided for holding and / or arranging the spindle nut (2) on a housing element (15). [3] Valve drive according to one of the preceding claims, characterized bythat the nut coupling unit (18, 19) is designed to tilt the spindle nut (2) and thereby transfer the spindle nut (2) from one of the operating positions to the other operating position. [4] Valve drive according to one of the preceding claims, characterized by that an extension of the pivot axis (16) has an intersection point with the rotation axis (11) of the spindle shaft (3). [5] Valve drive according to one of the preceding claims, characterized by that each of the operating positions corresponds to a coupling state. [6] Valve drive according to one of the preceding claims, characterized by that the coupling states are superimposed and arranged at an angle to each other. [7] Valve drive according to one of the preceding claims, characterized by that the spindle shaft (3) has at least one thread (13) and that the spindle nut (2) has at least one threaded section (12) for the thread (13). [8] Valve drive according to claim 7, characterized by that the threaded portion (12) is in engagement with the thread (13) in the first coupling state and that the threaded portion (12) is disengaged from the thread (13) in the second coupling state. [9] Valve drive according to one of the preceding claims 7 or 8, characterized by that the spindle nut (2) has at least a first threaded section (12) at a first end region viewed in the direction of the axis of rotation (11) and a second threaded section (12) spaced from the first threaded section (12) in the direction of the axis of rotation (11) at a second end region arranged opposite the first end region viewed in the direction of the axis of rotation (11). [10] Valve drive according to one of the preceding claims 7 to 9, characterized bythat the first threaded section (12) is arranged on a first side, viewed transversely to the axis of rotation (11), and the second threaded section (12) is arranged on a second side of the spindle nut (2) opposite the first side, viewed transversely to the axis of rotation (11). [11] Valve drive according to one of the preceding claims, characterized by that at least one return unit (18, 22) is arranged for resetting the spindle nut (2) and / or that at least one return spring (23) is arranged for resetting the valve piston (25) or the spindle nut (2). [12] Valve drive according to claim 11, characterized by that the reset unit (18, 22) is designed as an emergency unit (18, 22) for positioning or setting the valve piston (25) or the spindle shaft (3) or the spindle nut (2) in an emergency position or in a center of the adjustment path. [13] Valve drive according to one of the preceding claims 11 or 12, characterized bythat the reset unit (18, 22) comprises at least one electromagnet (18).

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