Strain wave gear mechanism

Abstract

The invention relates to a strain wave gear mechanism comprising: a wave generator, the wave generator insert of which is rotatably mounted relative to a flexspline about an axis of rotation; a gear which meshes with the flexspline; and a measuring device which has at least one sensor and an evaluation device, wherein the evaluation device receives measurement signals from the at least one sensor and, based on the measurement signals, determines the rotational position and / or the rotational speed and / or the direction of rotation of the wave generator and / or of a transmission element rotating in accordance with the reduction ratio of the strain wave gear mechanism, in particular relative to the gear or relative to the flexspline, or the evaluation device is designed as a torque measuring device. The strain wave gear mechanism is characterised in that the sensor and the evaluation device are arranged axially in the region of the flexspline.

Description

[0001] tension shaft gear

[0002] The invention relates to a stress wave transmission with a wave generator, the wave generator insert of which is mounted so as to be rotatable about a rotation axis relative to a flexspline, and with a gear that meshes with the flexspline, and with a measuring device that has at least one sensor and an evaluation device, wherein the evaluation device receives measurement signals from the at least one sensor and determines from the measurement signals the rotational position and / or the speed and / or the direction of rotation of the wave generator and / or of a transmission element rotating with the reduction ratio of the stress wave transmission, in particular relative to the gear or relative to the flexspline, or which is designed as a torque measuring device.

[0003] Gearboxes come in a variety of designs and are used to change motion quantities, often involving rotational movement. One possible design is a stress wave gear.

[0004] A stress wave transmission usually has a rigid, circular-section, internally toothed gear, called a circular spline, and a flexible, externally toothed gear, called a flexspline, which is arranged in the space surrounded by a rigid, internally toothed gear. A usually oval wave generator is rotatably arranged within the flexspline, the outer circumference of which has a bearing seat for a radially flexible rolling bearing. The wave generator is in contact with the radially flexible, externally toothed gear via the radially flexible rolling bearing. The radially flexible rolling bearing enables the wave generator to rotate relative to the radially flexible, externally toothed gear. The wave generator bends the rolling bearing and the flexspline into an oval shape in order to mesh the teeth of the circular spline and the flexspline along the vertical axis of the oval wave generator.

[0005] The flexspline has fewer teeth than the circular spline. When the wave generator rotates, the outer side of the flexspline rolls against the inner side of the circular spline, with the teeth of the flexspline circumferentially engaging and disengaging from the teeth of the circular spline on opposite sides. Due to the difference in the number of teeth, the flexspline rotates relative to the circular spline when the wave generator rotates and the flexspline is held in place, for example, relative to the gearbox housing. The wave generator is usually elliptical. However, any shape deviating from the circular shape is possible, resulting in the described engagement of the teeth of the flexible, externally toothed gear with the teeth of the rigid, internally toothed gear.It is also possible to design the wave generator in such a way that the teeth of the flexspline engage with the teeth of the circular spline at three or more points.

[0006] In the ring design of a stress wave gear, two internally toothed, rigid ring gears (circular spline and dynamic spline) with different numbers of teeth are present. Their teeth mesh with the external teeth of the radially flexible, externally toothed sleeve (flexspline). One of the internally toothed ring gears has the same number of teeth as the flexspline, while the other internally toothed ring gear has more teeth than the flexspline.

[0007] WO 2010 142318 A1 discloses a device for measuring the torque transmitted to an output shaft of a stress wave transmission. The device comprises a housing, a circular spline mounted in the housing, and a flex spline mounted on the output shaft. The device also includes sensors arranged between the circular spline and the housing for measuring forces, as well as a computing unit that receives measurement signals from the sensors and calculates the transmitted torque based on them.

[0008] European patent application EP 4257848 A1 discloses a transmission system comprising a torque-supporting element and a three-shaft transmission. The three-shaft transmission has at least one, in particular annular, gear. The gear is designed as a flange or has a flange. The gear is secured to the torque-supporting element by means of an elastically deformable coupling component, which has a counterflange that is rotationally connected to the flange.

[0009] From the German patent DE 10 2020 107 674 B3 a stress wave transmission device is known which comprises a stress wave transmission with a first gearwheel which functions as a circular spline, a second gearwheel which functions as a flex spline, a wave generator and a spatially fixed component, wherein a coding embodiment is arranged on one of the gearwheels or the wave generator and at least one sensor is provided on the spatially fixed component which is designed to detect the coding embodiment in a contactless manner.

[0010] European patent application EP 4 130 512 A1 discloses a stress wave transmission in a ring design with two internally toothed ring gears, in which a crossed roller bearing acts as the output bearing. The output bearing is arranged axially in the area of ​​the flexspline. One of the internally toothed ring gears of the stress wave transmission is designed as a component of a torque measuring device. A very similarly constructed stress wave transmission is known from WO 2023 132 109 A1.

[0011] It is the object of the present invention to provide a stress wave transmission which offers high measurement reliability with a compact design.

[0012] The task is solved by a stress wave transmission, which is characterized in that the sensor and the evaluation device are arranged axially in the area of ​​the flexspline.

[0013] The stress wave transmission according to the invention has the very special advantage of improved measurement accuracy, a more compact design, increased protection, and optimized signal transmission, which overall increases the efficiency and reliability of the stress wave transmission. In particular, the signal transmission from the at least one sensor to the evaluation unit is almost optimal due to the spatial proximity between the sensor and evaluation unit, which significantly increases the accuracy of the recording of the measured variables. In particular, long electrical cables susceptible to interference are avoided. The stress wave transmission according to the invention enables direct recording of relevant measured variables such as direction of rotation, rotational position, speed, and / or torque at a central location in the transmission, allowing measurements to be carried out with high accuracy and low signal distortion.A further advantage lies in the compact design, achieved by integrating the sensors into the axial area of ​​the flexspline. This facilitates the integration of the stress wave gear according to the invention into machines, especially robots, and drive systems. Furthermore, the evaluation device in the stress wave gear according to the invention is protected from external influences such as dirt or moisture.

[0014] The flexspline can extend axially from a first plane perpendicular to its rotation axis to a second plane perpendicular to its rotation axis, wherein the evaluation device and at least a part of the measuring device are arranged at least partially, preferably completely, between the first and the second plane.

[0015] The part of the measuring device arranged axially in the region of the flexspline can be at least one deformation body and / or at least one deformation measuring sensor and / or a circuit board with electrical or electronic components and / or a rotary encoder.

[0016] In an advantageous embodiment, several deformation bodies are part of the measuring device, in particular the torque measuring device. It can advantageously be provided that the deformation bodies elastically movably connect a first transmission component element and a second transmission component element such that one of the transmission component elements can be rotated about a rotation axis relative to the other of the transmission component elements by the application of torque. Here, each deformation body is preferably designed and arranged such that the force acting on it due to the application of torque is exclusively a compressive force or exclusively a tensile force.

[0017] In an advantageous embodiment, the stress wave transmission comprises a transmission base, in particular a transmission chassis or a transmission housing. In particular, the stress wave transmission can have an output component that is rotatably mounted relative to the transmission base by means of an output bearing arranged axially in the region of the flexspline. Such a stress wave transmission can advantageously be designed to be particularly compact. This is particularly the case if the stress wave transmission is designed as a pot-type or hat-type transmission.

[0018] The output bearing can advantageously be designed as a rolling bearing. The use of a crossed roller bearing as the output bearing is particularly advantageous because a crossed roller bearing has particularly high bending and tilting stiffness. In particular, the output bearing can also be a cylindrical roller bearing, a four-point contact bearing, a multi-row rolling bearing, or a multi-row ball bearing. An output bearing designed as a plain bearing is also possible.

[0019] The output bearing can advantageously be arranged so that it surrounds the flexspline. This design is particularly compact.

[0020] It can advantageously be provided that the output component is a circular spline or a dynamic spline or a flex spline or that the output component is a transmission component that is torsionally and rigidly connected to a circular spline or a dynamic spline or a flex spline, for example screwed or glued or welded.

[0021] In general, the drive component can be formed by a shaft generator insert of the shaft generator.

[0022] In a stress wave transmission, for example, a wave generator insert mounted so that it can rotate relative to a flexspline can act as the transmission drive and a circular spline as the output component, while a flexspline fastened to the transmission base acts as the fixed shaft. Alternatively, it is also possible for a transmission designed as a stress wave transmission to have a wave generator insert mounted so that it can rotate relative to a flexspline as the transmission drive and a flexspline as the output component, while a circular spline fastened to the transmission base acts as the fixed shaft.

[0023] The stress wave gear can advantageously be designed, in particular, as a pot gear or a hat gear. In a design designed as a hat gear, the flexspline has a rim, on whose outer circumference a flange is arranged. The flange can be designed for coupling to the gear base, for example, a gear chassis or a gear housing, or for coupling to a shaft. In a design designed as a pot gear, the flexspline has a pot base, which can have a flange for coupling to the gear base, for example, a gear chassis or a gear housing, or for coupling to a shaft.

[0024] Preferably, the evaluation device and / or the torque measuring device are arranged at a distance from the external toothing of the flexspline. Such a design is particularly straightforward to implement.

[0025] The stress wave gear can alternatively be designed as a ring gear and have a ring-shaped flexspline. In such a design, for example, a wave generator insert mounted for rotation relative to the flexspline can act as the gear drive and a circular spline (preferably designed as an internally toothed ring gear) can act as the output component, while a dynamic spline (preferably designed as an internally toothed ring gear) that is rotationally fixed to the gear base acts as the fixed shaft.

[0026] The torque measuring device preferably comprises at least one deformation body and at least one deformation measuring sensor, which is designed and arranged to detect the deformation (in particular bending, shearing, compression, and / or elongation) of the deformation body caused by the application of torque. The deformation measuring sensor can, for example, comprise at least one strain gauge. However, alternatively or in addition to at least one strain gauge, other measuring means, for example a piezo-based length measuring sensor, can also be present to detect the deformation of the deformation body. The deformation body can, for example, be designed as a bending beam. Alternatively, the deformation body can, for example, be designed as a tension or compression rod.

[0027] Preferably, the torque measuring device comprises a plurality of deformation bodies, each with at least one deformation measuring sensor.

[0028] In a particular embodiment, the torque measuring device has two, in particular annular or ring-segment-shaped, gear component elements which are elastically movably connected to one another by means of a plurality of deformation bodies, wherein it can be provided in particular that at least one deformation measuring sensor is arranged on each of the deformation bodies.

[0029] The gear element rotating with the reduction ratio of the stress wave gear can, for example, be the flexspline if the gear is fixed to the gear housing and the wave generator acts as the gear drive. The gear element rotating with the reduction ratio of the stress wave gear can, for example, be the gear if the flexspline is fixed to the gear housing and the wave generator acts as the gear drive. The gear element rotating with the reduction ratio of the stress wave gear can, for example, be another gear meshing with the flexspline if the stress wave gear is designed as a ring gear and the wave generator acts as the gear drive. In the latter case, for example, the gear can function as a dynamic spline and the other gear as a circular spline, or vice versa.

[0030] In an advantageous embodiment, the flexspline has external teeth. In this embodiment, the gear is an internally toothed ring gear. In particular, the gear can be a circular spline or a dynamic spline of the stress wave transmission.

[0031] Another design is also possible in the form of a so-called external rotor, in which the flexspline has an internal toothing, while the circular spline has an external toothing.

[0032] The electronic evaluation device is preferably designed and configured to receive measurement signals from the at least one deformation measurement sensor and to determine therefrom a torque and / or a rotational speed of a transmission shaft and / or a rotational position of a transmission shaft and / or a direction of rotation of a transmission shaft.

[0033] In a particularly advantageous embodiment, the evaluation device records the measurement signals as a function of time.

[0034] A particularly advantageous embodiment is one in which the measuring device comprises at least one deformation sensor that measures a deformation, particularly radial, of the gear and / or a transmission component connected to the gear or the flexspline caused by the shape of the wave generator. The deformation sensor can advantageously comprise at least one strain gauge.

[0035] Even if the gear or the gear component connected to the gear or flexspline can be considered stiff, particularly with regard to their primary function within the stress wave transmission, small elastic deformations of the gear or gear component occur due to the periodic loading from the rotating wave generator. Although these elastic deformations are small, they exhibit characteristic patterns that arise from the interaction between the wave generator, flexspline, and gear. Preferably, the gear and gear component are designed to be just as stiff as in the stress wave transmissions known from the prior art. At the very least, the gear and gear component are designed to be so stiff that these minor elastic deformations have no influence, or at least no significant influence, on the primary function of the gear and gear component within the stress wave transmission.

[0036] It was recognized that these small elastic deformations can be measured, and information about the rotational position, speed, or direction of rotation of the shaft generator or the gear component can be derived from them. For example, it can advantageously be provided that an evaluation device performs a Fourier analysis of the measurement signals in order to identify periodic patterns in the deformations and take these into account in the evaluation. From the measurement signal, a kinematic variable, namely the speed, rotational position, and / or direction of rotation, and a dynamic variable, namely the torque, can be derived. These are essential parameters of a precision gear. The concept therefore uses an indirect measurement technique in which structural reactions to the excitation by the rotating shaft generator are analyzed.

[0037] The transmission component can advantageously be attached to the gear or to the flexspline. In particular, the transmission component can be attached to the gear or to the flexspline in a force-fitting, form-fitting, and / or material-fitting manner. For example, the transmission component can be attached to the gear or to the flexspline by means of one or more screw connections.

[0038] In a particularly precise and reliable design, the deformation measurement sensor has at least one deformation section whose shape continuously and repeatedly changes during rotation of the wave generator, particularly when the stress wave gear is unloaded. The deformation section can be formed, for example, by a section of the gear and / or the gear component connected to the gear or to the flexspline.

[0039] To detect the change in the shape of the deformation section, a measuring sensor, for example, at least one strain gauge, can be glued to the deformation section. However, alternatively or in addition to the at least one strain gauge, other measuring sensors, for example, a piezo-based length measuring sensor, can also be attached to the deformation section to detect the deformation.

[0040] In an advantageous embodiment, the deformation section is a compression section that experiences a continuously changing compressive load during rotation of the wave generator, especially when the stress wave gear is unloaded. In particular, the deformation section can advantageously be designed and arranged such that it experiences exclusively compressive loads during rotation of the wave generator. Such a design operates with particular precision.

[0041] It can also be provided that the deformation section is a tensile section that experiences a continuously changing tensile load during rotation of the wave generator, especially when the stress wave gear is unloaded. In particular, the deformation section can advantageously be designed and arranged such that it experiences only tensile loads during rotation of the wave generator. Such a design operates with particular precision.

[0042] The stress wave transmission preferably has a plurality of deformation sections. It can advantageously be provided that some of the deformation sections are compression sections and others are tension sections.

[0043] In a special design, the deformation section is continuously subjected to alternating compressive and tensile loads during rotation of the wave generator, particularly when the stress wave gear is unloaded.

[0044] In another embodiment, the deformation section is designed and arranged in such a way that it experiences a continuously changing bending load and / or shear load during rotation of the wave generator, in particular even when the stress wave gear is unloaded.

[0045] In a particularly precise design, a first group of deformation measuring sensors and a second group of deformation measuring sensors are provided. For example, a total of six deformation measuring sensors can be provided, with the first, third, and fifth deformation measuring sensors being assigned to the first group of deformation measuring sensors, while the second, fourth, and sixth deformation measuring sensors are assigned to the second group of deformation measuring sensors, viewed in the direction of rotation.The evaluation device processes the measurement signals of the first group of deformation measuring sensors and the second group of deformation measuring sensors separately from one another, wherein a comparison of the results is subsequently carried out for plausibility and / or a final result for the rotational position and / or the speed and / or the direction of rotation of the wave generator and / or the rotating gear element relative to the gear is obtained by calculating the results.

[0046] In a particularly advantageous embodiment, the evaluation device determines the current rotational position of the wave generator and / or the rotating gear element starting from an initial rotational position, taking into account a measured temporal profile of the measurement signals. In particular, it can advantageously be provided that the evaluation device determines the current rotational position of the wave generator and / or the rotating gear element starting from an initial rotational position, taking into account a measured temporal profile of the measurement signals and the gear reduction. Such an embodiment is particularly reliable.

[0047] The deformation sensor can be arranged, for example, on the gear or on the transmission component. In particular, the deformation sensor can comprise at least one strain gauge that is bonded to the gear or the transmission component.

[0048] In a particularly advantageous embodiment, the deformation measuring sensor is formed on a connector or part of a connector which connects two gear component elements of the gearwheel to one another, in particular elastically movable, or which connects two gear component elements of the gear component to one another, in particular elastically movable, or which connects the gearwheel to the gear component, in particular elastically movable, or which connects the gear component to another gear component, in particular elastically movable, or which connects the gear component to the flexspline, in particular elastically movable.In particular, a plurality of connectors, which are designed as deformation measuring sensors or are each part of a deformation measuring sensor, can be present, each of which connects two gear component elements of the gearwheel, in particular elastically movable, to one another, or which connects two gear component elements of the gear component, in particular elastically movable, to one another, or which connects the gearwheel to the gear component, in particular elastically movable, or which connects the gear component to another gear component, in particular elastically movable, or which connects the gear component to the flexspline, in particular elastically movable.

[0049] The connector can have a first fastening section and a second fastening section for fastening to the aforementioned components. The fastening can have a force-fitting, form-fitting, and / or material-fitting connection. In a particularly advantageous embodiment, the fastening of the connector is designed to be non-destructively removable. Such a design is particularly flexible in use, particularly with regard to later conversion and / or maintenance of the stress wave gear.

[0050] In general, it can advantageously be provided that the connector has at least one pressure section that is subjected to pressure, in particular exclusively to pressure. Such a design makes it possible, for example, to measure the pressure forces and, from the measured pressure forces, to infer the rotational position and / or the speed and / or the direction of rotation of the wave generator and / or the rotating gear element relative to the gear. The pressure section can in particular be designed as a pressure rod. The pressure rod, in turn, can be formed by a leg of the connector, in particular one of several legs of the connector.

[0051] Likewise, quite generally, it can advantageously be provided that the connector has at least one tensile section that is subjected to tensile stress, in particular exclusively tensile stress. Such a design makes it possible, for example, to measure the tensile forces and, from the measured tensile forces, to infer the rotational position and / or the rotational speed and / or the direction of rotation of the wave generator and / or the rotating gear element relative to the gear. The tensile section can, in particular, be designed as a tensile rod. The tensile rod, in turn, can be formed by a leg of the connector, in particular one of several legs of the connector.

[0052] In a particularly advantageous embodiment, the connector has at least one compression section and at least one tension section. Such a design makes it possible, for example, to measure the compression and tension forces simultaneously. Such a measurement is particularly accurate and robust against disturbances.

[0053] In particular, it can be provided that a section of the connector forms the pressure section in one direction of rotation of a shaft of the transmission, for example the drive shaft of the transmission, and the tension section in an opposite direction of rotation of the shaft.

[0054] The connector can advantageously have a U-shaped cross-section. Such a design allows, for example, one of the legs of the U-shaped connector in cross-section to be inserted, in particular axially or radially, into a first plug-in recess of the respective component for the purpose of fastening, in particular in a clamping and / or precise manner, and the other leg of the U-shaped connector in cross-section to be inserted, in particular axially or radially, into a second plug-in recess of the respective component for the purpose of fastening, in particular in a clamping and / or precise manner.

[0055] The connector can advantageously have an S-shaped cross-section, an X-shaped cross-section, or a V-shaped cross-section. For example, such a design can include axial plug-in pins that are inserted into axial plug-in recesses of the respective component for fastening purposes.

[0056] In a particularly advantageous embodiment, the connector is designed such that, depending on the sign of the torque, at least one leg of the connector is the tensile section and at least one other leg of the connector is the compressive section. Such a design is particularly precise and allows accurate measurement if the legs function as part of a deformation sensor, wherein, for example, at least one strain gauge can be glued to each of the individual legs. However, alternatively or in addition to at least one strain gauge, other measuring means, such as a piezo-based length measuring sensor, can also be present to detect the deformation of the connector.

[0057] The connector can generally advantageously have at least two legs, wherein in particular one of the legs forms the pressure section and the other the tension section.

[0058] As already mentioned, the stress wave transmission according to the invention preferably has a plurality of deformation measuring sensors. The deformation measuring sensors can be arranged distributed in the circumferential direction. In particular, the deformation measuring sensors can be arranged such that the distances between immediately adjacent deformation measuring sensors are equal. However, a particularly advantageous embodiment is one in which the deformation measuring sensors are arranged such that the distances between immediately adjacent deformation measuring sensors are unequal. Such an asymmetrical arrangement of the deformation measuring sensors allows, in particular, a particularly precise determination of the rotational position and / or the direction of rotation of the wave generator and / or the rotating transmission element relative to the gear. One advantage of an asymmetrical arrangement of a plurality of deformation measuring sensors with unequal spacing is that it enables measurements with greater precision and fewer ambiguities.If the strain measurement sensors are arranged symmetrically, certain periodic patterns can occur in the measurement signals that are ambiguous with regard to evaluation. By distributing the strain measurement sensors unevenly, this problem is avoided or at least reduced. An asymmetric sensor arrangement therefore makes it possible to determine finer details about the movement of the shaft generator or the gear element. In particular, by performing a Fourier analysis in combination with an asymmetric arrangement, particularly good evaluation results can be achieved to determine the rotational position and / or speed and / or direction of rotation of the shaft generator with particularly high accuracy.

[0059] In general, it can advantageously be provided that the deformation measurement sensors are arranged asymmetrically. Alternatively or additionally, the wave generator can also be designed asymmetrically. For example, the wave generator can be designed such that the cams that press the flexspline radially outward (which are identical if the wave generator has an elliptical cross-section) differ from one another, for example, with regard to their distance from the rotation axis and / or their curvature.

[0060] In a particularly versatile embodiment of the stress wave transmission according to the invention, it is provided that the at least one deformation measuring sensor detects, in addition to the deformation of the gearwheel or of the transmission component connected to the gearwheel caused by the shape of the wave generator, an additional deformation caused by a transmitted or supported torque of the loaded stress wave transmission, and that the evaluation device calculates a torque value from the detected additional deformation.

[0061] In general, the deformation measuring sensor can advantageously be arranged on the gear or on the transmission component.

[0062] In an advantageous embodiment, the measuring device comprises a rotary encoder for detecting the rotational position, the rotational speed, and / or the direction of rotation of the shaft generator or of a gear element rotating with the reduction ratio, in particular relative to the gear or the flexspline. There are no fundamental restrictions with regard to the design of the rotary encoder. The rotary encoder can advantageously comprise a rotary encoder sensor and a coding embodiment that interacts, preferably contactlessly, with the rotary encoder sensor, for example in the form of a graduation disk, a toothed ring, or a magnetic wheel. It can advantageously be provided that the rotary encoder sensor transmits its measurement signals to the evaluation device. The rotary encoder can, for example, be designed as an optical rotary encoder comprising a coding disk with printed or engraved markings that is optically scanned by the rotary encoder sensor.Another variant is a magnetic encoder, which uses a Hall sensor or a magnetoresistive sensor to detect the movement of a permanent magnet ring or a magnetized gear ring. Alternatively, an inductive encoder can be used, which detects the movement of a metallic target object via an electromagnetic field. Another possibility, for example, is a capacitive encoder, which measures changes in capacitance between rotating and stationary electrodes.

[0063] A particularly advantageous design is one in which at least part of the rotary encoder and the evaluation device are arranged on a common carrier, in particular on a common circuit board. This integration reduces assembly effort and saves space, as the sensors can be compactly integrated into the system. Furthermore, cabling effort is reduced, which lowers both manufacturing costs and the risk of contact problems or electromagnetic interference. A combination of rotary encoder and evaluation device arranged on a common circuit board also allows for reliable direct signal processing, as long signal cables are avoided. This design offers the advantage of synergy, as the arrangement on a common carrier achieves great compactness and reliable signal processing.

[0064] In a particularly advantageous embodiment, the measuring device comprises two separate measuring devices, in particular two different measuring devices. For example, one of the measuring devices can contain deformation measuring sensors, as described above, while the other measuring device comprises a rotary encoder.

[0065] In a particularly precise design, the stress wave transmission comprises, in addition to a measuring device having at least one deformation measuring sensor that measures a deformation, in particular radial, of the gear and / or a transmission component connected to the gear or the flexspline caused by the shape of the wave generator, an additional rotary encoder for detecting the rotational position, speed, and / or direction of rotation of the wave generator or of a transmission element rotating with the reduction ratio, in particular relative to the gear or the flexspline. This addition can significantly increase the accuracy of the detection of the measured variables. While measurement via deformation sensors already enables precise indirect detection, the additional rotary encoder permits direct and redundant measurement, whereby the measured values ​​can be verified and potential measurement errors can be detected.Especially in applications with high demands on position accuracy, such as in robotics or precision drives, the combination of both measuring methods can ensure outstanding accuracy and operational reliability.

[0066] Alternatively or additionally, it can advantageously be provided that the stress wave transmission, in addition to a torque measuring device which has at least one deformation measuring sensor, additionally has a rotary encoder for detecting the rotational position, the rotational speed and / or the direction of rotation of the wave generator or of a transmission element rotating with the reduction ratio, in particular relative to the gear or the flexspline.

[0067] The stress wave gear can advantageously be designed such that at least part of the encoder, in particular the entire encoder, is arranged axially in the area of ​​the flexspline. This positioning optimally utilizes the available installation space and enables a compact design of the gear. At the same time, it allows a direct coupling of the encoder to the gear element to be measured, enabling measurements with less backlash and greater precision. This arrangement offers significant advantages, as the sensor technology is compactly integrated into the existing mechanical structure of the gear. This design also has the advantage of synergy, as this special arrangement achieves good use of installation space and reliable signal processing.

[0068] In general, it can advantageously be provided that at least part of the sensor and the evaluation device are arranged on a common carrier, in particular on a common circuit board. This integration reduces assembly effort and saves installation space, as the sensor technology can be compactly integrated into the system. Furthermore, the cabling effort is reduced, which reduces both manufacturing costs and the risk of contact problems or electromagnetic interference. A combination of sensor and evaluation device arranged on a common circuit board also allows for reliable, more direct signal processing, as long signal lines are avoided. This design has the advantage of synergy, as the arrangement on a common carrier achieves great compactness and reliable signal processing.

[0069] In a particularly advantageous embodiment, the electronic evaluation device has an annular or ring-segment-shaped or cylindrical circuit board, in particular with electrical or electronic components. Such a design allows the electronic evaluation device to be arranged in a particularly space-saving manner such that it at least partially, in particular completely, surrounds the flexspline and / or the shaft generator and / or a shaft that is rotationally and rigidly connected to the shaft generator. The electronic evaluation device can have multiple circuit boards; even in such a design, it is advantageously possible for the electronic evaluation device to at least partially, in particular completely, surround the flexspline and / or the shaft generator and / or a shaft that is rotationally and rigidly connected to the shaft generator.

[0070] In another embodiment, the electronic evaluation device is arranged in the space surrounded by the flexspline.

[0071] A particularly compact design is one in which the electronic evaluation device at least partially surrounds the Flexspline.

[0072] In a particularly advantageous design, the electronic evaluation device is attached to an inner or outer ring of the output bearing. This design ensures a secure arrangement of the electronic evaluation device while still allowing for a compact design of the stress wave gear unit.

[0073] As already mentioned, it can advantageously be provided that the flexspline extends axially from a first plane perpendicular to its rotational axis to a second plane perpendicular to its rotational axis, wherein the measuring device and the evaluation device are arranged at least partially, preferably completely, between the first plane and the second plane. In particular, it can additionally be provided that the output bearing is arranged between the first plane and the second plane.

[0074] An actuator which has a drive motor and a transmission according to the invention which is connected downstream of the drive motor is particularly advantageous.

[0075] In a particularly advantageous embodiment, the evaluation device is designed to control or regulate the drive motor depending on a sensor measurement value from the at least one deformation sensor. In particular, the evaluation device can be designed to throttle and / or stop the drive motor if a predefined or predeterminable sensor measurement value is exceeded, if a predefined or predeterminable sensor measurement value is undershot, or if a predefined or predeterminable sensor measurement value range is exceeded. In this way, overloading of the transmission can be avoided.

[0076] A robot, in particular an industrial robot, that includes at least one gear mechanism or actuator according to the invention is particularly advantageous. In particular, the gear mechanism according to the invention can be used in a robot joint. The robot joint can be used and monitored in a particularly versatile manner through the use of the gear mechanism according to the invention.

[0077] Of particular advantage is a chassis, in particular an active chassis, for a motor vehicle that has at least one transmission or actuator according to the invention. A particularly advantageous feature is that high overload protection and reliable monitoring of the transmission can be easily implemented, thus increasing driving safety. A steering system, in particular a car steering system or a truck steering system, that has at least one transmission according to the invention is of particular advantage. The steering system can, in particular, be a power steering system and / or a superimposed steering system.

[0078] The subject matter of the invention is illustrated schematically and by way of example in the drawing and is described below with reference to the figures, wherein identical or similarly acting elements are generally provided with the same reference numerals even in different embodiments. In the drawings:

[0079] Fig. 1 shows a first embodiment of a stress wave transmission according to the invention,

[0080] Fig. 2 shows a connector of the first embodiment of a stress wave transmission according to the invention,

[0081] Fig. 3 shows a second embodiment of a stress wave transmission according to the invention,

[0082] Fig. 4 is a detailed view of the second embodiment with a view along the rotation axis, wherein the gear housing and the evaluation device are not shown,

[0083] Fig. 5 the circular spline of the second embodiment,

[0084] Fig. 6 the rear view of one of the connectors for an inventive

[0085] Stress wave transmission according to the second embodiment,

[0086] Fig. 7 shows the front view of one of the connectors for an inventive

[0087] Stress wave transmission according to the second embodiment, Fig. 8 is a side view of one of the connectors for a stress wave transmission according to the invention

[0088] Stress wave transmission according to the second embodiment,

[0089] Fig. 9 shows a third embodiment of a stress wave transmission according to the invention,

[0090] Fig. 10 shows a fourth embodiment of a stress wave transmission according to the invention,

[0091] Fig. 1 1 a fifth embodiment of an inventive

[0092] stress wave transmission, and

[0093] Fig. 12 a sixth embodiment of an inventive

[0094] Stress wave transmission.

[0095] Figure 1 shows a first embodiment of an inventive

[0096] Stress wave transmission in a cross-sectional view along the rotation axis 28.

[0097] The stress wave transmission has a wave generator 1 comprising a wave generator insert 33, which is mounted for rotation about a rotation axis 28 relative to a flexspline 2 by means of a radially flexible roller bearing 12. The flexspline 2 has an external toothing 3. The stress wave transmission also has a gear 4, which forms a circular spline 15 and has an internal toothing 5. The internal toothing 5 engages with the external toothing 3 of the flexspline 2 at two opposite points.

[0098] The hat-shaped flexspline 2 has a flange 6 on its brim, which is elastically and movably connected to the outer ring 8 of an output bearing 32, namely a crossed roller bearing 9, by means of several connectors 7 arranged offset in the circumferential direction. The flange 6 can be constructed in several parts to facilitate assembly of the stress wave gear, but this is not shown for the sake of clarity. An inner ring 10 of the crossed roller bearing 9 is torsionally and rigidly connected to the gear 4. The outer ring 8 of the crossed roller bearing 9 is torsionally and rigidly connected to a gear housing 11.

[0099] The flange 6 has a plurality of radial plug-in recesses 13 for first plug-in sections 14 of the connectors 7, which have a U-shaped cross section. The outer ring 8 of the crossed roller bearing 9 has a plurality of radial plug-in recesses 13 for plug-in sections 14 of the connectors 7, which have a U-shaped cross section.

[0100] For example, the wave generator 1 can act as a gear drive and the circular spline 15 as a gear output, while the flex spline 2 attached to the gear housing 11 via the flange 6, the connectors 7 and the outer ring 8 acts as a fixed shaft.

[0101] The stress wave transmission has a measuring device 34 which includes several sensors 35 and an evaluation device 19.

[0102] Each of the connectors 7 has a deformation measuring sensor 16 which detects a deformation of a deformation body 29 formed by a deformation portion of the connector 7.

[0103] As already mentioned, the stress wave transmission also has an evaluation device 19. The evaluation device 19 receives the measurement signals from the at least one deformation measurement sensor 16 and determines from the measurement signals the rotational position and / or the rotational speed and / or the direction of rotation of the wave generator 1 and / or the flexspline 2 (and / or another rotating transmission element) relative to the gear 4. The evaluation device 19 has an annular plate that is attached to the outer ring 8.

[0104] The flexspline 2 extends axially from a first plane 30 perpendicular to its rotation axis to a second plane 31 perpendicular to its rotation axis.

[0105] The evaluation device 19 and the sensors 35 are arranged axially in the region of the flexspline 2, namely between the first plane 30 and the second plane 31. In this embodiment, the output bearing 32 is also arranged between the first plane 30 and the second plane 31, which is advantageous but not absolutely necessary.

[0106] Figure 2 shows a very schematic perspective detailed view of one of the connectors 7 of the first embodiment of a transmission according to the invention. The two legs of the U-shaped connector 7 function as plug-in sections 14, which are inserted into the radial plug-in recesses 13 of the flange 6 and the outer ring 8. Additionally, fastening can be achieved by means of screws (not shown) that extend through bores 20 in the legs of the U-shaped connector 7. The deformation section 17 connecting the legs of the U-shaped connector 7 functions as a deformation body 29, to which strain gauges 18 are glued to detect the respective elastic deformation.

[0107] Figure 3 shows a second embodiment of a stress wave transmission according to the invention. The stress wave transmission has a transmission housing 11 and a gear 4, namely a circular spline 15. The gear 4 (circular spline 15) is shown separately in Figure 5. The circular spline 15 is rotationally connected to the transmission housing 11.

[0108] The gear 4 (circular spline 15) has a first gear component element 21 and a second gear component element 22, which are elastically movably connected to one another by means of four connectors 7, each of which is fastened to the first gear component element 21 and the second gear component element 22. The first gear component element 21 is designed as a ring and has a plurality of axial bores, which are designed as plug-in recesses 13 for plug-in pins 23 of the connectors 7. The second gear component element 22 is designed as an internally toothed ring and also has a plurality of axial bores, which are designed as plug-in recesses 13 for plug-in pins 23 of the connectors 7.

[0109] The stress wave transmission also features a radially flexible, externally toothed, cup-shaped flexspline 2, which is arranged axially in the area of ​​its toothing in the space surrounded by the circular spline 15 and which has a flange 6 at the bottom of the cup. Arranged within the flexspline 2 is a wave generator 1 with a wave generator insert 33 and a radially flexible rolling bearing 12, which has an inner ring 24, an outer ring 25, and rolling elements 26. The wave generator 1 is rotationally connected to a transmission drive shaft 27. The wave generator 1 bends the flexspline 2 into an oval shape in order to engage the toothings of the circular spline 15 and the flexspline 2 along the vertical axis of the wave generator 1.

[0110] The stress wave transmission has a measuring device 34 which includes several sensors 35 and an evaluation device 19.

[0111] Each of the connectors 7 has deformation measuring sensors 16 which detect a deformation of deformation bodies 29 formed by the two legs of the connector 7.

[0112] The stress wave transmission also has an evaluation device 19 that receives measurement signals from the at least one deformation measurement sensor 16 and uses the measurement signals to determine the rotational position and / or the rotational speed and / or the direction of rotation of the wave generator insert 33 and / or the flexspline 2 (or another rotating transmission element) relative to the gear 4. The evaluation device 19 can be ring-shaped and attached to the transmission housing 11.

[0113] The evaluation device 19 and the sensors 35 are arranged axially in the region of the flexspline 2, namely between the first plane 30 and the second plane 31. In this embodiment, the output bearing 32 is also arranged between the first plane 30 and the second plane 31, which is advantageous but not absolutely necessary.

[0114] Figure 4 shows a detailed view of the second embodiment with a viewing direction along the rotation axis 28, wherein, among other things, the gear housing 11 and the evaluation device 19 are not shown for the sake of better clarity.

[0115] Figure 5 shows the circular spline of the second embodiment shown separately.

[0116] Figures 6 to 8 show various views of one of the connectors 7 of the stress wave transmission according to the invention shown in Figure 3. Figure 6 shows the rear view of one of the connectors 7. This figure shows that the connector 7 has a V-shaped deformation section 17, which can be made, for example, from a punched sheet metal. A strain gauge 18 is glued to the back of each leg of the V-shaped deformation section 17, which makes it possible to measure the tensile or compressive forces acting on the legs of the V-shaped deformation section 17.

[0117] On the V-shaped deformation section 17, protruding plug pins 23 are arranged on the front side, which are inserted into the plug recesses 13.

[0118] Figure 9 shows a third embodiment of an inventive

[0119] Stress wave transmission in a cross-sectional view along the rotation axis 28.

[0120] The stress wave transmission has a wave generator 1 comprising a wave generator insert 33, which is mounted for rotation about a rotation axis 28 relative to a flexspline 2 by means of a radially flexible roller bearing 12. The flexspline 2 has an external toothing 3. The stress wave transmission also has a gear 4, which forms a circular spline 15 and has an internal toothing 5. The internal toothing 5 engages with the external toothing 3 of the flexspline 2 at two opposite points.

[0121] A flange 6 of the flexspline 2 is arranged on the brim of the hat-shaped flexspline 2. This flange 6 is elastically and movably connected to the outer ring 8 of an output bearing 32, namely a crossed roller bearing 9, by means of several connectors 7 arranged offset in the circumferential direction. The flange 6 can be constructed in several parts to facilitate assembly of the stress wave gear, although this is not shown for the sake of clarity. An inner ring 10 of the crossed roller bearing 9 is torsionally and rigidly connected to the gear 4. The outer ring 8 of the crossed roller bearing 9 is torsionally and rigidly connected to a gear housing 11.

[0122] The flange 6 is directly connected to the outer ring 8 of the crossed roller bearing 9, for example by means of screw connections.

[0123] For example, the wave generator 1 can act as a gear drive and the circular spline 15 as a gear output, while the flex spline 2 attached to the gear housing 11 via the flange 6, the connectors 7 and the outer ring 8 acts as a fixed shaft.

[0124] The stress wave transmission has a measuring device 34, which includes an evaluation device 19 and a rotary encoder 36 as a sensor 35.

[0125] The rotary encoder 36 serves to determine the rotational position, the speed and / or the direction of rotation of a gear element rotating with the reduction ratio, namely the inner ring 10 connected to the circular spline 15.

[0126] The rotary encoder 36 has a rotary encoder sensor 37 and a coding embodiment 38 that interacts contactlessly with the rotary encoder sensor 37, for example in the form of a dial, a toothed ring or a magnetic wheel.

[0127] The rotary encoder sensor 37 and the evaluation device 19 are arranged on a common carrier 39, namely on a common circuit board.

[0128] The flexspline 2 extends axially from a first plane 30 perpendicular to its rotation axis to a second plane 31 perpendicular to its rotation axis. The evaluation device 19 and the rotary encoder 36 are arranged axially in the region of the flexspline 2, namely between the first plane 30 and the second plane 31.

[0129] The stress wave transmission also includes an evaluation device 19. The evaluation device 19 receives the measurement signals from the rotary encoder 36 and uses the measurement signals to determine the rotational position and / or the speed and / or the direction of rotation of the wave generator 1 and / or the flexspline 2 (and / or another rotating transmission element) relative to the gear 4. The evaluation device 19 includes an annular plate attached to the outer ring 8.

[0130] Figure 10 shows a fourth embodiment of a stress wave transmission according to the invention. The fourth embodiment is essentially constructed in the same way as the first embodiment, but unlike the first embodiment, sensor 35 functions as a torque measuring device.

[0131] The torque measuring device comprises a plurality of deformation bodies 29 with deformation measuring sensors 16. The deformation bodies 29 are designed and arranged such that the deformation of the deformation body caused by the application of torque can be detected by means of the strain gauges 18 of the deformation measuring sensors 16. The measurement signals from the deformation measuring sensors 16 are received by the evaluation device 19 and evaluated by the evaluation device to determine the currently acting torque.

[0132] The flexspline 2 extends axially from a first plane 30 perpendicular to its rotation axis to a second plane 31 perpendicular to its rotation axis. The evaluation device 19 and the sensor 35 are arranged axially in the region of the flexspline 2, namely between the first plane 30 and the second plane 31.

[0133] Figure 11 shows a fifth embodiment of a stress wave transmission according to the invention.

[0134] In the stress wave transmission of the fifth exemplary embodiment, the measuring device 34 includes two sensors 35, namely a sensor 35 containing deformation measuring sensors and functioning to detect the rotational position, the rotational speed, and / or the direction of rotation of the inner ring 10, and a rotary encoder 36. Both sensors 35 are connected to the same evaluation device 19. By using two sensors 35, the accuracy of the detection of the measured variables can be significantly increased. While measurement via deformation sensors 16 already enables precise indirect detection, the additional rotary encoder 36 allows for direct and redundant measurement, whereby the measured values ​​can be verified and possible measurement errors can be detected. Particularly in applications with high demands on position accuracy, such as in robotics or precision drives, the combination of both measuring methods can ensure outstanding accuracy and operational reliability.

[0135] In addition, the sensor 35, which includes deformation measuring sensors 16, can function to detect a torque.

[0136] The flexspline 2 extends axially from a first plane 30 perpendicular to its rotation axis to a second plane 31 perpendicular to its rotation axis. The evaluation device 19 and both sensors 35 are arranged axially in the region of the flexspline 2, namely between the first plane 30 and the second plane 31.

[0137] The rotary encoder sensor 33 and the evaluation device 19 are arranged on a common carrier 39, namely on a common circuit board.

[0138] Figure 12 shows a sixth embodiment of an inventive

[0139] Stress wave transmission in a cross-sectional view along the rotation axis 28.

[0140] The stress wave transmission has a wave generator 1 comprising a wave generator insert 33, which is mounted for rotation about a rotation axis 28 relative to a flexspline 2 by means of a radially flexible roller bearing 12. The flexspline 2 has an external toothing 3. The stress wave transmission also has a gear 4, which forms a circular spline 15 and has an internal toothing 5. The internal toothing 5 engages with the external toothing 3 of the flexspline 2 at two opposite points.

[0141] A flange 6 of the flexspline 2 is arranged on the brim of the hat-shaped flexspline 2. This flange 6 is elastically and movably connected to the outer ring 8 of an output bearing 32, namely a crossed roller bearing 9, by means of several connectors 7 arranged offset in the circumferential direction. The flange 6 can be constructed in several parts to facilitate assembly of the stress wave gear, although this is not shown for the sake of clarity. An inner ring 10 of the crossed roller bearing 9 is torsionally and rigidly connected to the gear 4. The outer ring 8 of the crossed roller bearing 9 is torsionally and rigidly connected to a gear housing 11.

[0142] The stress wave transmission has a torque measuring device 34 as a sensor 35.

[0143] The flange 6 is connected to the outer ring 8 via the torque measuring device 34. For example, the shaft generator 1 can function as the gear drive and the circular spline 15 as the gear output, while the flex spline 2, which is attached to the gear housing 11 via the flange 6 and the torque measuring device 34, functions as the fixed shaft.

[0144] The stress wave transmission also has an evaluation device 19 that receives measurement signals from the torque measuring device 34 and determines a torque therefrom. The flexspline 2 extends axially from a first plane 30 perpendicular to its rotational axis to a second plane 31 perpendicular to its rotational axis, with the output bearing 32 and the evaluation device 19 arranged between the first plane 30 and the second plane 31.

[0145] The rotary encoder 36 has a rotary encoder sensor 37 and a coding embodiment 38 that interacts contactlessly with the rotary encoder sensor 37, for example, in the form of a dial, a toothed ring, or a magnetic wheel. The rotary encoder sensor 37 and the evaluation device 1 are arranged on a common carrier 39, namely on a common circuit board. The evaluation device 19 also receives measurement signals from the rotary encoder sensor 37.

[0146] The flexspline 2 extends axially from a first plane 30 perpendicular to its rotation axis to a second plane 31 perpendicular to its rotation axis. The evaluation device 19 and both sensors 35 are arranged axially in the region of the flexspline 2, namely between the first plane 30 and the second plane 31.

[0147]

[0148] 1 wave generator

[0149] 2 Flexsplines

[0150] 3 External gearing

[0151] 4 gear

[0152] 5 Internal gearing

[0153] 6 Flange

[0154] 7 connectors

[0155] 8 Outer ring

[0156] 9 crossed roller bearings

[0157] 10 inner ring

[0158] 1 1 Gearbox housing

[0159] 12 rolling bearings

[0160] 13 Plug-in recess

[0161] 14 plug-in sections

[0162] 15 Circular splines

[0163] 16 Deformation measuring sensor

[0164] 17 Deformation section

[0165] 18 strain gauges

[0166] 19 Evaluation device

[0167] 20 holes

[0168] 21 first transmission component element

[0169] 22 second transmission component element

[0170] 23 plug pins

[0171] 24 inner ring

[0172] 25 Outer ring

[0173] 26 rolling elements

[0174] 27 Gearbox drive shaft

[0175] 28 Rotation axis

[0176] 29 deformation bodies

[0177] 30 first level

[0178] 31 second level

[0179] 32 output bearings

[0180] 33 Shaft generator insert

[0181] 34 Measuring device

[0182] 35 Sensor

[0183] 36 Encoder Encoder Sensor Coding Embodiment Carrier

Claims

Patent claims 1. A stress wave transmission with a wave generator (1), the wave generator insert (33) of which is mounted so as to be rotatable about a rotation axis (28) relative to a flexspline (2), and with a gear (4) which meshes with the flexspline (2), and with a measuring device (34) which has at least one sensor and an evaluation device (19), wherein the evaluation device (19) receives measurement signals from the at least one sensor and determines from the measurement signals the rotational position and / or the speed and / or the direction of rotation of the wave generator (1) and / or of a transmission element rotating with the reduction ratio of the stress wave transmission, in particular relative to the gear (4) or relative to the flexspline (2), or which is designed as a torque measuring device, characterized in that the sensor (35) and the evaluation device (19) are arranged axially in the region of the flexspline (2).

2. Stress wave transmission according to claim 1, characterized in that the stress wave transmission has a transmission base, in particular a transmission chassis or a transmission housing (11), and an output component rotatably mounted relative to the transmission base by means of an output bearing (32) arranged axially in the region of the flexspline (2).

3. Stress wave transmission according to claim 2, characterized in that the output bearing (32) is designed as a rolling bearing, in particular a crossed roller bearing (9) or a cylindrical roller bearing or a four-point bearing or a multi-row rolling bearing or a multi-row ball bearing.

4. Stress wave transmission according to claim 2 or 3, characterized in that the output component is a circular spline (15) or a dynamic spline or the flex spline (2) or that the output component is a transmission part which is torsionally and rigidly connected to a circular spline (15) or a dynamic spline or the flex spline (2).

5. Stress wave transmission according to one of claims 1 to 4, characterized in that the wave generator insert (33) is a drive component of the stress wave transmission.

6. Stress wave gear according to one of claims 1 to 5, characterized in that the stress wave gear is designed as a pot gear or as a hat gear.

7. Stress wave transmission according to one of claims 1 to 6, characterized in that the stress wave transmission is designed as a ring transmission.

8. Stress wave transmission according to one of claims 1 to 7, characterized in that the torque measuring device has at least one deformation body (29) and at least one deformation measuring sensor (16).

9. Stress wave transmission according to claim 8, characterized in that the deformation measuring sensor (16) has at least one strain gauge (18).

10. Stress wave transmission according to claim 8 or 9, characterized in that the torque measuring device has two, in particular annular, transmission component elements (21, 22) which are elastically movably connected to one another by means of a plurality of deformation bodies (29). 1 1. Stress wave transmission according to one of claims 8 to 10, characterized in that the deformation body (29) is designed as a bending beam or that the deformation bodies (29) are designed as bending beams.

12. Stress wave transmission according to one of claims 8 to 10, characterized in that the deformation body (29) is designed as a tension or compression rod or that the deformation bodies (29) are designed as tension or compression rods.

13. Stress wave transmission according to one of claims 1 to 12, characterized in that the flexspline (2) is the transmission element rotating with the reduction ratio of the stress wave transmission or that the gear (4) is the transmission element rotating with the reduction ratio of the stress wave transmission.

14. Stress wave transmission according to one of claims 1 to 13, characterized in that a. that the flexspline (2) has an external toothing and that the gear (4) is an internally toothed ring gear, and / or that b. the gear (4) is a circular spline (15) or a dynamic spline.

15. Stress wave transmission according to one of claims 1 to 14, characterized in that the evaluation device (19) records the measuring signals as a function of time.

16. Stress wave transmission according to claim 1, characterized in that the measuring device (34) has at least one deformation measuring sensor (16) which measures a deformation of the gear (4) and / or of a transmission component connected to the gear (4) or to the flexspline (2) caused by the shape of the wave generator (1), in particular a radial deformation.

17. Stress wave transmission according to claim 16, characterized in that the deformation measuring sensor (16) has at least one strain gauge.

18. Stress wave transmission according to claim 16 or 17, characterized in that the deformation measuring sensor (16) has at least one deformation section (17) whose shape changes continuously and repeatedly during rotation of the wave generator (1), in particular also when the stress wave transmission is unloaded.

19. Stress wave transmission according to claim 18, characterized in that the deformation section (17) is a pressure section which experiences a continuously changing pressure load during rotation of the wave generator (1), in particular also when the stress wave transmission is unloaded.

20. Stress wave transmission according to claim 18, characterized in that the deformation section (17) is a tensile section which experiences a continuously changing tensile load during rotation of the wave generator (1), in particular also when the stress wave transmission is unloaded.

21. Stress wave transmission according to claim 18, characterized in that the deformation section (17) is continuously and alternately subjected to compression and tension during rotation of the wave generator (1), in particular also when the stress wave transmission is unloaded.

22. Stress wave transmission according to claim 18, characterized in that the deformation section (17) experiences a continuously changing bending load and / or shear load during rotation of the wave generator (1), in particular also when the stress wave transmission is unloaded.

23. Stress wave transmission according to one of claims 1 to 22, characterized in that the deformation measuring sensor (16) is arranged on the gear (4) or on the transmission component.

24. Stress wave transmission according to one of claims 16 to 22, characterized in that the deformation measuring sensor (16) is arranged on the transmission component.

25. Stress wave transmission according to one of claims 1 to 24, characterized in that the evaluation device (1) determines the respective current rotational position starting from an initial rotational position taking into account a measured temporal course of the measuring signals.

26. Stress wave transmission according to one of claims 1 to 25, characterized in that the deformation measuring sensor (16) is formed on a connector or is part of a connector which a. connects two transmission component elements of the gear wheel (4), in particular elastically movable, to one another or which b. connects two gear component elements of the gear component to one another, in particular in an elastically movable manner, or c. connects the gear wheel (4) to the gear component, in particular in an elastically movable manner, or d. connects the gear component to another gear component, in particular in an elastically movable manner, or e. connects the gear component to the flexspline (2), in particular in an elastically movable manner.

27. Stress wave transmission according to one of claims 16 to 26, characterized in that several deformation measuring sensors (16) are present.

28. Stress wave transmission according to claim 27, characterized in that the deformation measuring sensors (16) are arranged distributed in the circumferential direction.

29. Stress wave transmission according to claim 27 or 28, characterized in that the deformation measuring sensors (16) are arranged such that the distances between immediately adjacent deformation measuring sensors (16) are equal.

30. Stress wave transmission according to claim 28 or 29, characterized in that the deformation measuring sensors (16) are arranged such that the distances between at least two immediately adjacent deformation measuring sensors (16) are unequal.

31. Stress wave transmission according to claim 28 or 29, characterized in that the deformation measuring sensors (16) are arranged asymmetrically.

32. Stress wave transmission according to one of claims 1 to 31, characterized in that the wave generator (1) is designed asymmetrically.

33. Stress wave transmission according to one of claims 8 to 32, characterized in that the at least one deformation measuring sensor (16) detects, in addition to the deformation of the gear (4) or of the transmission component connected to the gear (4) caused by the shape of the wave generator (1), an additional deformation caused by a transmitted or supported torque of the loaded stress wave transmission, and in that the evaluation device (19) calculates a torque value from the detected additional deformation.

34. Stress wave transmission according to one of claims 1 to 33, characterized in that the measuring device (34) comprises a rotary encoder (36) for detecting the rotational position and / or the speed and / or the direction of rotation of the wave generator (1) and / or of a shaft rotating with the reduction ratio of the stress wave transmission. Gear element, in particular relative to the gear (4) or relative to the flexspline (2).

35. Stress wave transmission according to claim 34, characterized in that the rotary encoder (36) has a rotary encoder sensor (37) and a coding embodiment (38) which interacts, preferably contactlessly, with the rotary encoder sensor (37), for example in the form of a line disk, a line ring, a toothed ring or a magnetic wheel.

36. Stress wave transmission according to claim 34 or 35, characterized in that at least a part of the rotary encoder (36) and the evaluation device (19) are arranged on a common carrier, in particular on a common printed circuit board.

37. Stress wave transmission according to one of claims 1 to 36, characterized in that at least part of the sensor and the evaluation device (19) are arranged on a common carrier, in particular on a common circuit board.

38. Stress wave transmission according to one of claims 1 to 37, characterized in that the electronic evaluation device (19) has an annular or ring-segment-shaped or cylindrical circuit board.

39. Stress wave transmission according to one of claims 1 to 38, characterized in that the electronic evaluation device (19) has several circuit boards.

40. Stress wave transmission according to one of claims 1 to 39, characterized in that the electronic evaluation device (19) is arranged in the space surrounded by the flexspline (2).

41. Stress wave transmission according to one of claims 1 to 40, characterized in that the electronic evaluation device (19) at least partially surrounds the flexspline (2).

42. Stress wave transmission according to one of claims 1 to 41, characterized in that the electronic evaluation device (19) is attached to an inner ring (10) or to an outer ring (8) of the output bearing (32).

43. Stress wave transmission according to one of claims 1 to 42, characterized in that the flexspline (2) extends axially from a first plane (30) perpendicular to its axis of rotation to a second plane (31) perpendicular to its axis of rotation, wherein the measuring device (34) and the evaluation device (19) are arranged at least partially, preferably completely, between the first plane (30) and the second plane (31).

44. Stress wave transmission according to claim 43, characterized in that the output bearing (32) is arranged between the first plane (30) and the second plane (31).

45. Actuator comprising a drive motor and a transmission according to one of claims 1 to 44, which is connected downstream of the drive motor.

46. ​​Actuator according to claim 45, characterized in that the evaluation device (19) is designed to control or regulate the drive motor in dependence on the sensor signals.

47. Actuator according to claim 45 or 46, characterized in that the evaluation device (19) is designed to throttle and / or stop the drive motor when a predetermined or predeterminable sensor measured value is exceeded or when a predetermined or predeterminable sensor measured value is undershot or when a predetermined or predeterminable sensor measured value range is left.

48. Robot joint comprising at least one gear mechanism according to one of claims 1 to 44 and / or an actuator according to one of claims 45 to 47.

49. Robot comprising at least one gear mechanism according to one of claims 1 to 44 and / or an actuator according to one of claims 45 to 47.

50. Chassis, in particular active chassis for a motor vehicle, which has at least one according to one of claims 1 to 44 and / or an actuator according to one of claims 45 to 47.

51. Steering system, in particular car steering system or truck steering system, which has at least one transmission according to one of claims 1 to 44 and / or an actuator according to one of claims 45 to 47.

52. Steering system according to claim 51, characterized in that the steering system is a power steering system and / or a superposition steering system.

Images