Actuator in the field of automation technology
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-07
- Publication Date
- 2026-03-18
AI Technical Summary
Existing actuators in automation technology face challenges in achieving a compact structure while effectively absorbing and measuring axial forces, leading to increased size due to resilient bearing requirements.
An actuator design featuring a housing with an electric motor, gearbox, and a resilient spring device comprising a first and second spring element with different spring constants, mounted radially via a rolling bearing, allowing for compact force measurement and directional force consideration, integrated with a force measuring device to detect deflections and convert them into electronic signals.
The compact actuator structure enables robust and reliable force measurement across different directional loads, maintaining efficiency and precision in automation tasks.
Smart Images
Figure EP2024062612_14112024_PF_FP_ABST
Abstract
Description
[0001] Actuator for automation technology The invention relates to an actuator for automation technology, in which an output has a linearly or axially moving element. For example, DE212008000062U1 shows such an actuator. In the field of automation technology, it may be of interest to provide a spring-loaded output in order, for example, to absorb and measure axial forces that arise. However, the provision of such a spring-loaded mounting leads to an increase in the size of the actuator. The object of the invention can be seen as proposing an actuatorwhich has a compact design of the spring-loaded mounting and enables robust and reliable force measurement. The object is achieved by an actuator according to independent claim 1. An actuator according to the invention in automation technology, configured to actuate a valve, such as a valve, comprises: a housing with a housing wall; an electric motor; a gear; an electronic operating circuit for operating the electric motor; an output with a threaded spindle and a spindle nut, wherein the threaded spindle is rotationally fixed and configured to actuate a valve through an axial movement, wherein the electric motor, gear, and electronic operating circuit are arranged in the housing, wherein the electric motor is configured to drive the spindle nut rotationally by means of the gear and thereby move the threaded spindle axially,wherein the output is spring-mounted in the housing in an axial direction of the threaded spindle by means of a spring device, wherein the output assumes a rest position in the force-free state, wherein the actuator in particular has a force measuring device which is designed to measure a force of the output against the spring device or to detect a force limit, wherein the spring device has at least a first spring element and at least one second spring element, wherein the at least one first spring element is designed to effect a force against a deflection of the output from the rest position in a first direction, wherein the at least one second spring element is designed to effect a force against a deflection of the output from the rest position in a second,to effect a direction opposite to the first direction. In this way, a compact spring device can be set up. In one embodiment, the first spring element and the second spring element have different spring constants. In this way, a load on the output that depends on the direction of movement can be taken into account. For example, greater forces occur when closing a valve than when opening a valve, so that different measuring ranges are required for force measurement depending on the direction of movement. In one embodiment, the at least one first spring element and the at least one second spring element surround the output, wherein a cross-sectional plane of the first spring element and a cross-sectional plane of the second spring element have a distance of less than 30%, and in particular less than 25%,and is preferably less than 20% of a diameter of the first spring element or the second spring element. In this way, a spring device that is compact in the axial direction can be set up. In one embodiment, the spindle nut is mounted radially by means of a rolling bearing, which rolling bearing is arranged at least partially in a cylindrical recess in the housing wall, wherein the cylindrical recess provides a stop for the rolling bearing against movement towards a side of the cylindrical recess facing away from the housing, wherein the rolling bearing touches the stop when the output is in the rest position and / or is preloaded against the stop,wherein the at least one first spring element and the at least one second spring element act against the rolling bearing on a side of the rolling bearing facing the housing. The support of the first spring element and the second spring element from one side against the rolling bearing contributes to improved compactness of the spring device. In one embodiment, the actuator has a spring plate fastened in the housing with a central opening through which the spindle nut is guided. The spindle nut has a radial formation, in particular a collar, on a side of the spring plate facing away from the housing, which is designed to act directly or indirectly as a stop against the spring plate. The spring plate is designed as one of the at least one first spring element. In one embodiment, the spring plate is arranged outside the cylindrical recess.wherein the radial formation acts against the spring plate via the rolling bearing. In one embodiment, the gear has a first toothed element, such as a gearwheel, which is rotationally fixedly connected to the spindle nut, wherein the spring device has at least one disc spring, which at least one disc spring engages around the spindle nut and is designed as at least one of the at least one second spring element, wherein the at least one disc spring is arranged and clamped between the first toothed element and the rolling bearing. In one embodiment, the force measuring device is designed to convert a deflection of the output from the rest position against the spring device into a deflection-dependent measurement signal of an electronic measured variable, such as inductance, capacitance, current, or voltage, wherein the force measuring device or the electronic operating circuit is designed toto derive or calculate a measured value for the force from the measurement signal. In one embodiment, the force measuring device comprises a sensor for generating the measurement signal, such as a coil, a capacitor, or a photodiode. The force measuring device comprises a pick-up arm configured to be moved by an axial movement of the spindle nut and thereby to effect a change in the measurement signal of the electronic measurement variable. In one embodiment, the force measuring device comprises a lever device with a lever bearing and, with respect to the lever bearing, a first end and an opposite second end. The pick-up arm forms the first end, and the second end is configured to influence a measured value of the electronic measurement variable depending on the position.wherein a lever length of the first end is in particular smaller than a lever length of the second end. A smaller lever length of the first end allows a small deflection of the spring-mounted device to be translated into a larger change in the measurement signal. In one embodiment, the sensor comprises a sensor element with an end face, wherein the second end is configured to at least partially cover the end face, wherein a coverage ratio is dependent on the force against the spring device. The sensor element comprises a coil, wherein the second end is permanently magnetic and / or electrically conductive, wherein the second end is configured to influence an inductance of the coil and the second end, or the sensor element comprises a capacitor plate, wherein the second end is electrically conductive, wherein the second end is configured to influence a capacitance of the capacitor plate and the second end.or wherein the sensor element is a photodiode, wherein the second end is configured to attenuate or block the incidence of light, for example, by an LED. In one embodiment, the second end is disk-shaped. In one embodiment, measured values of the measurement signal occupy a value range with a maximum value and a minimum value, wherein a measured value of the measurement signal in the force-free state of the output takes a value that is less than 30%, and in particular less than 25%,and preferably less than 20% of a difference between the maximum value and the minimum value is removed from a mean value of the value range. In this way, a deflection of the spring-mounted device in both directions can be detected with sufficient detection margin. The invention is described below with reference to exemplary embodiments. Fig. 1 shows a cross-section through an exemplary actuator according to the invention. Fig. 2 shows an enlarged detail of the actuator shown in Fig. 1. Figs. 3 a) and b) outline sensors of an actuator according to the invention. Fig. 1 shows a cross-section through an exemplary actuator 1 according to the invention comprising a housing 10 with a housing wall 11, wherein an electric motor 20, an electronic operating circuit 40 for operating the electric motor, a gear 30, and an output 50 are arranged in the housing of the actuator. The output has a threaded spindle 51,The output is configured to actuate a valve by means of a rotary movement of the threaded spindle. The gear 50 is configured to transmit a force or torque from the electric motor to the output and comprises gear parts 51, such as gears 51.1 or worms, which are mounted on gear part bearings 32, such as gear axes 32.1 or gear shafts 32.2. The electric motor is configured to move the output axially, wherein the output is spring-mounted by means of a spring device 60. The actuator has a force measuring device 70, which force measuring device is configured toto measure a mechanical force causing the movement of the output from a deflection of the spring-mounted device from a rest position. The electronic operating circuit can then, for example, derive a drive efficiency of the actuator from force measured values relating to the output movement as well as from measured values of a mechanical motor force derived from motor current and / or motor voltage. Fig. 2 shows a section of the cross-section of the actuator 1 shown in Fig. 1. The spring device has at least one first spring element 61 and at least one second spring element 62, wherein the at least one first spring element is configured to cause a force against a deflection of the output from the rest position in a first direction, wherein the at least one second spring element is configured to cause a force against a deflection of the output from the rest position in a second,to effect a direction opposite to the first direction. The spindle nut 52 can, as shown here, be radially mounted by means of a rolling bearing 80, which rolling bearing is arranged at least partially in a cylindrical recess 11.1 of the housing wall, wherein the cylindrical recess provides a stop 11.11 for the rolling bearing against movement in the direction of a side of the cylindrical recess facing away from the housing. The rolling bearing touches the stop when the output 40 is in the rest position and / or is preloaded against the stop. The at least one first spring element 61 and the at least one second spring element 62 act against the rolling bearing on a side of the rolling bearing facing the housing. The cylindrical recess provides a stop 11.11 for the rolling bearing. In one embodiment, a spring plate 61.1 fastened in the housing has a central opening 61.11, through which opening the spindle nut 52 is guided.wherein the spindle nut has a radial formation 52.1, in particular a collar 52.11, on a side of the spring plate facing away from the housing, which is designed to act directly or indirectly as a stop against the spring plate, wherein the spring plate is designed as one of the at least one first spring element 61. The spring plate 61.1 is arranged outside the cylindrical recess 11.1, wherein the radial formation 52.1 acts against the spring plate via the rolling bearing 80. One of the toothed elements 31 of the gear 30 is rotationally fixedly connected to the spindle nut 52. In one embodiment, the spring device 60 has at least one disc spring 62.1, which at least one disc spring engages around the spindle nut and is designed as at least one of the at least one second spring element 62.wherein the at least one disc spring is arranged and clamped between the first toothed element and the rolling bearing. In this way, the spring device 60 can be implemented compactly. The force measuring device, as shown here by way of example, has the lever device 72 with a lever bearing 72.01 and with a first end 72.1 and, in particular, an opposite second end 72.2 with respect to the lever bearing, wherein the pick-up arm forms the first end, wherein the second end is configured to influence a measured value of the electronic measurement variable in a position-dependent manner, wherein a lever length of the first end is in particular smaller than a lever length of the second end. In one embodiment, the force measuring device 70 of an exemplary actuator according to the invention is configured toto convert a deflection of the spring-mounted device 61 from the rest position against the spring device 60 into a deflection-dependent measurement signal of an electronic measurement variable such as inductance, capacitance, current, or voltage, wherein the force-measuring device or the electronic operating circuit 30 is configured to derive or calculate a measured value for the force from the measurement signal. A sensor 71 of the force-measuring device is configured to generate a measurement signal corresponding to the propulsion force. The sensor can have an end face 71.1, wherein the second end 72.2 is configured to at least partially cover the end face, wherein a coverage portion depends on the propulsion force against the spring device and influences the measurement signal. Measured values of the measurement signal occupy a value range with a maximum value and a minimum value.wherein, in one embodiment, a measured value of the measurement signal in the force-free state of the output assumes a value which is less than 30%, and in particular less than 25%, and preferably less than 20% of a difference between the maximum value and the minimum value away from a mean value of the value range. In this way, a deflection of the spring-mounted device in both directions can be detected with sufficient detection margin. Sensor elements 71 are schematically sketched in Figs. 3 a) and 3 b). The sensor element can, as shown in Fig. 3 a), have a coil 71.2, wherein the second end is permanently magnetic and / or electrically conductive, wherein the second end is configured to influence an inductance of the coil and the second end. The sensor element can, as shown in Fig. 3 b), have a capacitor plate 71.3, wherein the second end is electrically conductive, wherein the second end is configured toto influence the capacitance of the capacitor plate and the second end. Alternatively, the sensor can comprise a photodiode 71.4, wherein the second end is configured to attenuate or block the incidence of light, for example, generated by an LED. The invention is not limited to the embodiments shown in Figs. 1, 2, and 3; features of the embodiments can be interchanged where technically feasible. / List of Reference Symbols,
[0002] List of reference symbols 1 Actuator 10 Housing 11 Housing wall 11.1 Cylindrical recess 11.11 Stop 20 Electric motor 30 Gearbox 31 Toothed element 31.1 Gear 40 Electronic operating circuit 50 Output 51 Threaded spindle 52 Spindle nut 52.1 Radial formation 52.11 Collar 60 Spring device 61 First spring element 61.1 Spring plate 61.11 Central opening 62 Second spring element 62.1 Disc spring 70 Force measuring device 70.1 Sensor 71 Sensor element 71.01 End face 71.1 Coil 71.2 Capacitor or capacitor plate 71.3 Photodiode 72 Lever device 72.01 Lever bearing 72.1 First end 72.11 Pick-up arm 72.2 Second end 80 Roller bearing
Claims
AMENDED CLAIMS received by the International Bureau on 30 September 2024 (30.09.2024) 1. Actuator (1) of automation technology designed to operate a fitting such as a valve comprising: A housing (10) with a housing wall (11); An electric motor (20); A gearbox (30); An electronic operating circuit (40) for operating the electric motor; An output (50) with a threaded spindle (51) and a Spindle nut (52), wherein the threaded spindle is rotationally fixed and is designed to be rotated by a Axial movement to operate a valve, whereby electric motor, gear and electronic Operating circuit are arranged in the housing, wherein the electric motor is designed to To drive the spindle nut rotationally by means of the gear and thereby move the threaded spindle axially, whereby the output in the housing is in an axial direction of the Threaded spindle is resiliently mounted by means of a spring device (60), wherein the output assumes a rest position in the force-free state, characterized in that the actuator has a force measuring device (70) which is designed to measure a force of the output against the spring device or to measure a force limit level, wherein the spring device has at least a first Spring element (61) and at least one second spring element (62), wherein the at least one first spring element is adapted to exert a force against a deflection of the output from the rest position in a first direction, wherein the at least one second spring element is designed to exert a force against a deflection of the downforce from the rest position into a second, the first direction to cause opposite direction.
2. Actuator according to claim 1, wherein the at least one first spring element (61) and the at least one second spring element (62) encompass the output (50), wherein a cross-sectional plane of the first spring element and a cross-sectional plane of the second spring element a distance less than 30%, and in particular less than 25%, and preferably less than 20% of a diameter of the first spring element (61) or the second spring element (62).
3. Actuator according to claim 1 or 2, wherein the spindle nut (52) is radially rolling bearing (80), which rolling bearing is at least partially mounted in a cylindrical recess (11.1) of the Housing wall is arranged, wherein the cylindrical recess provides a stop (11.1) for the rolling bearing against a movement in the direction of a side of the cylindrical recess facing away from the housing, wherein the rolling bearing, when driven in the rest position, stop and / or is prestressed against the stop, wherein the at least one first spring element (61) and the at least one second spring element (62) are arranged on a Housing facing side of the rolling bearing against the Rolling bearings work.
4. Actuator according to one of the preceding claims, wherein the actuator comprises a fixed in the housing (11) Spring plate (61.1) with a central opening (61.11), through which opening the spindle nut (52) is guided, wherein the spindle nut is mounted on a side facing away from the housing Side of the spring plate has a radial formation (52.1), in particular a collar (52.11), which is designed to act directly or indirectly as a stop against the spring plate, wherein the spring plate is one of the at least one first spring element (61).
5. Actuator according to claim 4, wherein the spring plate (61.1) outside the cylindrical Recess (11.1) is arranged, wherein the radial formation (52.1) acts against the spring plate via the rolling bearing.
6. Actuator according to one of the preceding claims, wherein the gear (30) has a first toothed element (31) such as a gear (31.1) which is rotationally fixedly connected to the spindle nut (52), wherein the spring device (60) has at least one Disc spring (62.1) which has at least one Disc spring engages around the spindle nut (52) and as at least one of the at least one second spring element (62), wherein the at least one disc spring is arranged between the first Gearing element and the rolling bearing are arranged and clamped.
7. Actuator according to one of the preceding claims, wherein the force measuring device (70) is designed to convert a deflection of the output from the rest position against the spring device into a deflection-dependent Measurement signal of an electronic quantity such as inductance, capacitance, current or voltage, whereby the force measuring device or the electronic Operating circuit (40) is arranged to To derive or calculate a measured value for the force from the measurement signal.
8. Actuator according to claim 7, wherein the force measuring device (70) comprises a sensor (70.1) with a sensor element (71) for generating the Measuring signal comprising, for example, a coil (71.1), a capacitor (71.2) or a photodiode (71.3), wherein the force measuring device has a pick-up arm (72.11) which is designed to be able to measure the measurement signal by an axial Movement of the spindle nut (52) and thereby causing a change in the measuring signal of the electronic measuring variable.
9. Actuator according to claim 8, wherein the force measuring device comprises a lever device (72) with a lever bearing (72.01) and with respect to the Lever bearing a first end (72.1) and a second end opposite the first end End (72.2), wherein the pick-up arm (72.11) forms the first end, wherein the second end is designed to determine a measured value of the electronic To influence the measured variable, wherein a lever length of the first end is in particular smaller than a lever length of the second end.
10. Actuator according to claim 9, wherein the sensor element (71) has an end face (71.01), wherein the second end (72.2) is designed to at least partially cover the end face, wherein a coverage proportion is dependent on the force against the spring device, wherein the sensor has a coil (71.1), wherein the second end is permanently magnetic and / or electrically conductive, wherein the second end is designed to inductance of the coil and the second end, or wherein the sensor comprises a capacitor plate (71.2), wherein the second end is electrically conductive, wherein the second end is adapted to to influence the capacitance of the capacitor plate and the second end, or wherein the sensor is a photodiode (71.3), wherein the second end is configured to attenuate or block an incidence of light, for example by an LED.
11. Actuator according to claim 9 or 10, wherein the second end (72.2) is disc-shaped.
12. Actuator according to one of the preceding claims 7 to 11, wherein measured values of the measuring signal occupy a value range with a maximum value and a minimum value, wherein a measured value of the measuring signal in the force-free state of the output takes a value which is less than 30%, and in particular less than 25%, and preferably less than 20% of a difference between the maximum value and Minimum value is away from a mean value of the value range.