Adjusting device

Abstract

The invention relates to an adjusting device (1), comprising a spindle drive (2), an adjusting element (3) which can be positioned by the spindle drive (2), and an optical measuring system (4), wherein the spindle drive (2) has a motor (22), a hollow threaded spindle (24) with a threaded spindle axis (A1), and a spindle nut (26) which is in threaded engagement with the threaded spindle (24), wherein the motor (22) directly or indirectly drives either the threaded spindle (24) or the spindle nut (26), and the actuating element (3) is connected either to the spindle nut (26) or to the threaded spindle (24), and the optical measuring system (4) comprises at least one first transmitting means (44) which emits a light beam (42) and at least one first receiving means (46) which interacts with the light beam (42), wherein the at least one first transmitting means (44) or at least parts thereof are / is arranged in a stationary manner on or outside the adjusting device (1) and the at least one first receiving means (46) or at least parts thereof are / is arranged movably on the actuating element (3), or the at least one first receiving means (46) or at least parts thereof are / is arranged in a stationary manner on or outside the adjusting device (1) and the at least one first transmitting means (44) or at least parts thereof are / is arranged movably on the actuating element (3), and the light beam (42) of the at least one first transmitting means (44) runs along the threaded spindle axis (A1) in the interior of the hollow threaded spindle (24) and concentrically with respect to the latter, and a direct positional determination of the adjusting element (3) is made possible on account of the interaction of the light beam (42) with the at least one first receiving means (46).

Description

Description Adjusting device

[0001] The invention relates to an adjusting device according to claim 1.

[0002] According to the applicant's internal prior art, various types of sensors are used in actuating devices with screw drives for the direct or indirect determination of the position of an actuating element of the actuating device to be adjusted or positioned. Rotary sensors for detecting a rotational movement of the respective element of the actuating device can be arranged on its motor, its brake, its gear, its spindle nut, or on its spindle. From the direct measurement or detection of the rotational movement of the corresponding element of the actuating device, the actuating movement generated by the screw drive or the position of the actuating element can be indirectly determined via gear parameters (such as the gear ratio or the spindle pitch). In addition, linear sensors, which are usually arranged on the actuating element itself, allow its position to be determined directly.

[0003] In the indirect position determination of the actuator outlined above, a disadvantage may arise from the presence of inaccuracies in the drive train, for example in the form of gear play, which reduce the accuracy of the position determination of the actuator.

[0004] However, the direct position determination of the actuating element outlined above can also be disadvantageous, since, depending on the structural or geometric design of the actuating device, positional deviations of the elements of the actuating device and, in particular, tilting of the elements of the screw drive can occur, which are transferred to the actuating element due to the mechanical coupling and which are mistakenly interpreted by the linear sensor as position information of the actuating element. On the other hand, it is possible that, due to the above-outlined Positional deviations can result in the actual actuating movements of the actuator not being detected or recognized by the linear sensor (so-called Abbe errors). In the worst case, the sensor detects position information that is opposite to the actual actuating movement, which can render any downstream control of the actuator's drive unstable.

[0005] Therefore, it is an object of the invention to provide an actuating device which enables a very precise position determination of the actuating element, regardless of any inaccuracies in the drive train and while avoiding Abbe errors.

[0006] This object is achieved by an adjusting device according to claim 1, wherein the subclaims contain at least expedient further developments.

[0007] In the actuating device according to the invention, which comprises a spindle drive, an actuating element that is moved and to be positioned by the spindle drive, and an optical measuring system, it is essential that the spindle drive has a hollow threaded spindle with a threaded spindle axis, along which a light beam of a transmitting device of the optical measuring system runs and, due to an interaction of the light beam running through the hollow threaded spindle with a receiving device, a direct and highly accurate position determination of the actuating element is possible.

[0008] Here, the optical measuring system comprises at least a first transmitting device for emitting the light beam and at least one first receiving device cooperating therewith, wherein either the first transmitting device or at least parts thereof is / are arranged in a stationary manner on or outside the actuating device and the first receiving device or at least parts thereof is / are arranged movably on the actuating element, or the first receiving device or at least parts thereof is / are arranged in a stationary manner on or outside the actuating device and the first transmitting device or at least parts thereof is / are arranged movably on the actuating element.

[0009] By orienting the light beam along the threaded spindle axis and thus concentrically to and within the threaded spindle, it is impossible for inaccuracies in the drive train to influence the measurement of the actuator's position. It is even possible to detect or identify inaccuracies in the drive train. Due to the concentric arrangement of the light beam with respect to the threaded spindle, the measurement axis coincides with the force flow axis, which also effectively prevents Abbe errors.

[0010] The actuating device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the motor of the spindle drive has a hollow shaft with a hollow shaft axis, wherein the hollow shaft axis is arranged in alignment with the threaded spindle axis, and the light beam runs along the threaded spindle axis and along the hollow shaft axis or concentrically with the threaded spindle axis and concentrically with the hollow shaft axis. Thus, the advantageous arrangement of the light beam, which is congruent with the threaded spindle axis, can be implemented easily and without great effort, particularly in embodiments of the actuating device in which the motor of the spindle drive is arranged in the extension of the threaded spindle or the threaded spindle axis, i.e., is arranged approximately behind the threaded spindle.

[0011] The actuating device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that a hollow shaft gear with a hollow shaft gear axis is arranged between the motor and the hollow threaded spindle, and the hollow shaft gear axis is arranged in alignment with the threaded spindle axis and the hollow shaft axis, and the light beam runs along the threaded spindle axis and along the hollow shaft axis and along the hollow shaft gear axis. In this way, even in embodiments in which a hollow shaft motor and the hollow threaded spindle a gear or a hollow shaft gear is arranged, the advantageous arrangement or the advantageous course of the light beam along the threaded spindle axis can be implemented in a simple and uncomplicated manner.

[0012] The actuating device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the motor is arranged laterally spaced from the threaded spindle or laterally spaced from the threaded spindle axis and is operatively connected to the spindle axis via a gear mechanism or to the spindle nut, for example, via a belt or spur gear. This enables a space-saving folded design of the actuating device, particularly with regard to the length.

[0013] The actuating device according to the invention can be realized with any other feature provided according to the invention of a combination of features described herein in such a way that the light beam is a laser beam.

[0014] The positioning device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the optical measuring system is designed as or comprises an interferometer. Interferometers allow for particularly high measurement resolution down to the sub-nanometer range, thus enabling correspondingly precise positioning by means of the positioning device.

[0015] The actuator according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the transmitting device comprises an optical fiber in which the light beam is guided. An optical fiber allows for dedicated beam guidance, in particular beam guidance around corners or along bends, which is possible without the use of additional optical elements.

[0016] The actuating device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the optical measuring device comprises a second transmitter device emitting a light beam and a second receiver device interacting with the light beam of the second transmitter device, wherein the second receiver device is movably arranged on the threaded spindle or on the spindle nut, and the second transmitter device is arranged stationary on or outside the actuating device, wherein the second light beam extends at least partially at a distance from the threaded spindle axis. In this way, a further and additional measurement signal can be obtained, which can be used for redundancy purposes or for noise reduction.

[0017] The actuating device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that it has a device for recording and processing measurement or operating data relevant to the state of the actuating device, which device is designed to record and process the measurement or operating data during the running time of the actuating device and to optionally link them together so that an image of the state of the actuating device can be derived therefrom.

[0018] Advantages and benefits of the invention will become clearer from the following description of preferred embodiments with reference to the figures. They show:

[0019] Fig. 1 : Schematic representation of an adjusting device according to the invention, in which the motor drives the threaded spindle directly

[0020] Fig. 2: Schematic representation of an adjusting device according to the invention, in which a hollow shaft gear is arranged between the motor and the threaded spindle

[0021] Fig. 3: Schematic representation of an adjusting device according to the invention, in which the motor is arranged laterally next to the threaded spindle

[0022] Fig. 4: Schematic representation of an adjusting device according to the invention, in which the motor drives the spindle nut

[0023] Fig. 5: Schematic representation of an actuating device according to the invention, which, in modification of Fig. 1, has two transmitting devices and two receiving devices

[0024] Fig. 1 shows a schematic representation of an actuating device 1 according to the invention. This comprises a spindle drive 2 with a motor 22, which drives a hollow threaded spindle 24 directly coupled to the spindle, thereby causing it to rotate. The hollow threaded spindle 24 has a threaded spindle axis A1, which is arranged concentrically to the threaded spindle 24 and runs through its cross-sectional center. A spindle nut 26 is in threaded engagement with the external thread of the threaded spindle via its internal thread. The spindle nut 26 is mechanically coupled to an actuating element 3, which is to be driven or positioned via the spindle nut 26, in such a way that a rotary movement of the spindle nut 26 is prevented, and thus the rotary movement of the threaded spindle 24 is converted into a linear movement of the spindle nut 26 or of the actuating element 3 connected to it.

[0025] The motor 22 has a hollow shaft with a hollow shaft axis A2, which is aligned with the threaded spindle axis A1. A first transmitting device 44 of an optical measuring system 4, arranged within the hollow shaft axis A2, emits a light beam 42 in the form of a laser beam, which runs along the hollow shaft axis A2 and along the threaded spindle axis A1 and strikes a first receiving device 46, which is mechanically coupled or connected to the actuating element 3. The interaction of the laser beam of the stationary transmitting device 44 with the movably arranged receiving device 46 enables a direct and highly precise determination of the position of the actuating element 3.

[0026] It should be noted that the first transmitting device 44 is not necessarily arranged within the motor 22 or within its hollow shaft. It is also conceivable for the transmitting device 44 to be arranged outside the motor, for example, to the left of the motor 22 in Fig. 1. Furthermore, it is conceivable for the motor 22 to drive not the threaded spindle 22, but rather the spindle 26, thereby causing it to rotate, resulting in a linear movement of the threaded spindle 24, which is prevented from rotating.

[0027] Fig. 2 shows a schematic representation of a further embodiment of an actuating device 1 according to the invention. The only difference from the actuating device 1 shown in Fig. 1 is that the actuating device shown in Fig. 2 additionally comprises a hollow shaft gear 5 arranged between the motor 22 and the threaded spindle 4, said gear having a hollow shaft gear axis A3 which is aligned with the hollow shaft axis A2 of the hollow shaft motor 22 and aligned with the threaded spindle axis A1, so that the light beam 42 emitted by the transmitting device 44 in the form of a laser beam can readily interact with the receiving device 46 arranged on the actuating element 3.

[0028] Fig. 3 schematically shows a further embodiment of an actuating device 1 according to the invention, in which, in contrast to the embodiment shown in Fig. 2, the motor is not arranged behind the threaded spindle or in the extension of the threaded spindle axis, but laterally spaced therefrom (so-called folded arrangement). Via a gear 6, which comprises a drive element 62 driven directly by the motor 22 and an output element 64 coupled to the drive element 62 via a connecting element 66 in the form of a belt, an indirect and rotary drive of the threaded spindle 24 is achieved. This leads to a linear movement of the spindle nut 26 threadedly engaged with the threaded spindle 24 and thus to a linear actuating or positioning movement of the actuating element 3 coupled to the spindle nut 26.

[0029] Here, the output element 64 has a hollow shaft 642, the hollow shaft axis of which is arranged in alignment with the threaded spindle axis A1 and the light beam 42 emitted by the transmitting device 44 arranged at a distance from the output element 64 runs in the form of a laser beam along the hollow shaft axis of the output element 64 and along the threaded spindle axis A1 or coincides therewith and can therefore interact with the receiving device 46 arranged on the actuating element 3 for determining the position of the actuating element 3.

[0030] Fig. 4 shows a schematic view of a further embodiment of an actuating device 1 according to the invention, in which the motor 22 does not drive the threaded spindle 24, but rather the spindle nut 26. For this purpose, the spindle drive 2 has a hollow drive shaft 28 which is directly coupled to both the motor 22 and the spindle nut 26. Due to this mechanical coupling, the rotary drive movement of the motor 22 leads to a rotation of the hollow drive shaft 28 and also to a rotation of the spindle nut 26. Since the spindle nut 26 is fixed in position due to the coupling to the hollow drive shaft 28, the rotation of the spindle nut 26 causes a linear movement of the threaded spindle 24, which, depending on the drive direction of rotation of the motor 22, ensures that the threaded spindle 24 moves in or out of the hollow drive shaft 28.Due to the mechanical coupling of the threaded spindle 24 with the actuating element 3, the linear movement of the threaded spindle 24 leads to a linear actuating or positioning movement of the actuating element 3.

[0031] The receiving device 46 is arranged on the actuating element 3 and is located within the hollow threaded spindle 24 and surrounded or enclosed by it. The transmitting device 44, which interacts with the receiving device 46, is arranged within the hollow shaft of the motor 22. The light beam 42 emitted by it, in the form of a laser beam, runs along the hollow shaft axis A2 of the motor 22 and the threaded spindle axis A1, with the hollow shaft axis A2 being aligned with the threaded spindle axis A1.

[0032] Fig. 5 schematically shows a further embodiment of an actuating device 1 according to the invention, the only difference of which from the actuating device shown in Fig. 1 is that it additionally comprises a second transmitting device 442 emitting a light beam 422 in the form of a laser beam and a receiving device 462 cooperating therewith. The second transmitting device 442 is fixedly arranged on a part of the actuating device 1 not shown in Fig. 5, while the second receiving device 462 is movably arranged on the spindle nut 26.

[0033] A wide variety of further embodiments of the actuating device according to the invention are conceivable. In particular, it is conceivable that, in a modification of the embodiments according to Figures 1 to 5, the receiving device 46, 462 comprises an optical element, such as a mirror element, and is part of the respective receiving device 46, 462, wherein the mirror element is arranged as a purely passive element on the movable actuating element 3 or connected thereto, while the part of the respective receiving device 46, 462, which is generally provided with or connected to at least one cable for transmitting energy or data, is arranged stationary on or outside the actuating device. This applies in particular to embodiments in which the optical measuring system comprises an interferometer or is designed as such.

[0034] It is also conceivable for the threaded spindle to be designed as a telescopic spindle with several nested or folded hollow threaded spindles. In this case, it is conceivable to detect the position of each of the individual threaded spindles separately using a respective combination of transmitting and receiving devices.

[0035] List of reference symbols 1 adjusting device 2 spindle drive 3 Control element 4 optical measuring system 5 hollow shaft gearboxes 6 gearboxes 22 Engine 24 threaded spindle 26 spindle nut 28 hollow drive shaft 42 Light beam (of the first transmitting device 44) 44 first transmitting device (of the optical measuring system 4) 46 first receiving device (of the optical measuring system 4) 422 Light beam (of the second transmitting device 442) 442 second transmitting device (of the optical measuring system 4) 462 second receiving device (of the optical measuring system 4) A1 Threaded spindle axis A2 hollow shaft axis A3 Hollow shaft gear axis

Claims

Claims Claim 1. Adjusting device (1) comprising a spindle drive (2), an adjusting element (3) to be positioned by the spindle drive (2), and an optical measuring system (4), wherein the spindle drive (2) has a motor (22), a hollow threaded spindle (24) with a threaded spindle axis (A1), and a spindle nut (26) threadably engaged with the threaded spindle (24), wherein the motor (22) drives either the threaded spindle (24) or the spindle nut (26) directly or indirectly, and the adjusting element (3) is connected either to the spindle nut (26) or to the threaded spindle (24), and the optical measuring system (4) comprises at least one first transmitting device (44) emitting a light beam (42) and at least one first receiving device (46) cooperating with the light beam (42),wherein the at least first transmitting device (44) or at least parts thereof is / are arranged stationary on or outside the actuating device (1) and the at least first receiving device (46) or at least parts thereof is / are arranged movably on the actuating element (3), or the at least first receiving device (46) or at least parts thereof is / are arranged stationary on or outside the actuating device (1) and the at least first transmitting device (44) or at least parts thereof is / are arranged movably on the actuating element (3), and the light beam (42) of the at least first transmitting device (44) runs along the threaded spindle axis (A1) inside the hollow threaded spindle (24) and concentrically thereto, and due to the interaction of the light beam (42) with the at least first receiving device (46), a direct position determination of the actuating element (3) is possible. Claim 2. Adjusting device (1) according to claim 1, characterized in that the motor (22) has a hollow shaft axis (A2), wherein the hollow shaft axis (A2) is arranged in alignment with the threaded spindle axis (A1), and the light beam (42) runs along the threaded spindle axis (A1) and along the hollow shaft axis (A2). Claim 3 Adjusting device (1) according to claim 2, characterized in that between the motor (22) and the hollow threaded spindle (24) a Hollow shaft gear (5) is arranged with a hollow shaft gear axis (A3) which is aligned with the threaded spindle axis (A1) and with the hollow shaft axis (A2), and the light beam (42) runs along the threaded spindle axis (A1) and along the hollow shaft axis (A2) and along the hollow shaft gear axis (A3). Claim 4 Adjusting device (1) according to claim 1, characterized in that the motor (22) is arranged laterally spaced from the threaded spindle (24) and is operatively connected to the latter or to the spindle nut (26) via a gear (6). Claim 5 Adjusting device (1) according to one of the preceding claims, characterized in that the light beam (42) is a laser beam. Claim 6 Adjusting device (1) according to one of the preceding claims, characterized in that the optical measuring system (4) is designed as an interferometer or comprises such an interferometer. Claim 7 Adjusting device (1) according to one of the preceding claims, characterized in that the at least first transmitting device (44) has an optical fiber in which the light beam (42) is guided. Claim 8 Adjusting device (1) according to one of the preceding claims, characterized in that the optical measuring device (4) comprises a second transmitter device (442) emitting a light beam (422) and a second receiver device (462) interacting with the light beam (422) of the second transmitter (442), wherein the second receiver device (462) or at least parts thereof is or are arranged movably on the threaded spindle (24) or on the spindle nut (26), and the second transmitter device (442) or at least parts thereof is or are arranged stationary on or outside the adjusting device (1), wherein the second light beam (422) runs at least partially at a distance from the threaded spindle axis (A1) of the hollow threaded spindle (24). Claim 10 Actuating device (1) according to one of the preceding claims, characterized in that it has a device for detecting and processing measurement or operating data relevant to the state of the actuating device (1), which device is designed to accompany the measurement or operating data during the running time of the actuating device (1). to record and process them and optionally to link them together so that an image of the state of the actuating device (1) can be derived therefrom.

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